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Papers by jose gonzales

SSRN Electronic Journal, 2004

We modify the paper of Stahl (1989) on sequential consumer search in an oligopoly context by rela... more We modify the paper of Stahl (1989) on sequential consumer search in an oligopoly context by relaxing the assumption that consumers obtain the first price quotation for free. When all price quotations are costly to obtain, a new equilibrium arises where consumers randomize between not searching at all and searching for one price. The region of parameters for which this equilibrium exists becomes larger as the number of shoppers decreases and/or the number of firms increases. The comparative statics properties of this new equilibrium are interesting. In particular, the expected price increases as search cost decreases, and is constant in the number of shoppers and in the number of firms. We show that the Diamond result never obtains with truly costly search.

Anales de la Facultad de Medicina, 2013

Objetivos: Detectar el genoma proviral de HTLV-1 mediante el desarrollo de reacción en cadena de ... more Objetivos: Detectar el genoma proviral de HTLV-1 mediante el desarrollo de reacción en cadena de la polimerasa (PCR). Diseño: Descriptivo. Institución: D.A. Microbiología Médica, Facultad de Medicina, UNMSM. Participantes: Personas con y sin sospecha de HTLV-I. Principales medidas de resultados: detección de HTLV-1 mediante PCR. Resultados: El 71,4% de los pacientes con sospecha clínica de HTLV-I fue reactivo por métodos Inmunológico. Elisa HTLV I-II Biokit detectó 5 casos reactivos (X=2,359 ± DE: 0,7309); los dos casos con sospecha clínica de HTLV- I fueron no reactivos (DO: 0,007 y 0,04); los tres casos con antecedente clínico de estrongiloidiosis fueron no reactivos al Elisa (DO: 0,029, 0,001 y 0,00). El promedio de los sueros no reactivos con antecedente clínico de HTLV-1 y estrongiloidiosis fue 0,0154 ±0,018. En el grupo de voluntarios sanos, el promedio de las DO fue 0,0085 ± 0,0068. Al comparar los grupos, se observó que hubo diferencias significativas entre el grupo HTLV-1 y...

Anales de la Facultad de Medicina, 2013

Objetivos: Caracterizar las moléculas de respuesta humoral anti Paragonimus mexicanus/P. peruvian... more Objetivos: Caracterizar las moléculas de respuesta humoral anti Paragonimus mexicanus/P. peruvianus para diferenciar la infección en fase aguda y fase crónica, mediante la evaluación de la dinámica de la respuesta inmune. Diseño: Observacional, longitudinal. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM Material biológico: Animales de experimentación. Principales medidas de resultados: Determinación de IgG e IgM anti Paragonimus. Resultados: Existió diferencia significativa de medias de la DO entre los grupos crónico y no infectados para los anticuerpos IgG anti ES de Paragonimus. Los anticuerpos IgM anti Paragonimus tuvieron una ligera elevación entre los días 7 a 20 post inoculación (pi), y una tendencia hacia la disminución entre los días 40 y 60 pi. Conclusiones: La dinámica de producción de anticuerpos IgG e IgM anti Paragonimus mediante Elisa indirecto, diferenció la fase aguda de la fase crónica, en los gatos inoculados.

Quintessence Publicacion Internacional De Odontologia, May 1, 2007

Resumen: El presente estudio aleatorizado multicéntrico tenía por objetivo comparar la eficacia t... more Resumen: El presente estudio aleatorizado multicéntrico tenía por objetivo comparar la eficacia terapéutica de las proteínas derivadas de la matriz del esmalte (Emdogain®, grupo experimental) con la de la regeneración tisular guiada por medio de membranas (Resolur ...

Http Dx Doi Org 10 1902 Jop 2004 75 8 1150, Jan 11, 2005

The objective of this multicenter, randomized trial was to compare enamel matrix derivative (EMD;... more The objective of this multicenter, randomized trial was to compare enamel matrix derivative (EMD; test) with barrier membranes (control) for the treatment of mandibular buccal Class II furcation defects. Forty-five patients with 90 comparable defects on contralateral molars were included. Defects were randomly assigned to EMD or bioabsorbable barrier membrane; the contralateral defect received the alternative treatment. Assessments at baseline and 8 and 14 months included gingival margin levels, probing depths, bleeding on probing, vertical attachment levels, and vertical bone sounding from a stent at five buccal sites/ tooth. Defect dimensions were recorded at surgery and during reentry at 14 months. Change of open horizontal furcation depth was the primary outcome variable. Adverse reactions and patient perceptions were also noted. Both treatment modalities led to significant clinical improvements. The median reduction of open horizontal furcation depth was 2.8 mm with the corresponding interquartile interval (1.5 mm, 3.5 mm) at test sites compared with 1.8 mm (1.0 mm, 2.8 mm) at control sites. The Hodges-Lehmann estimator of the advantage (reduction test versus control) was 0.75 mm (95% confidence interval [CI]: 0.125 mm, 1.375 mm, P = 0.033, Wilcoxon). The frequency of complete furcation closure was 8/45 (test) and 3/45 (control); partial closure, 27/45 in both groups; no change, 9/45 and 11/45, respectively; and deterioration, 1/45 and 4/45, respectively. The frequency of no pain or no swelling at 1 week post-surgery was 62% and 44%, respectively, at the test sites and 12% and 6% at the control sites. There was a significantly greater reduction in horizontal furcation depth and a comparatively lower incidence of postoperative pain/swelling following enamel matrix derivative compared to membrane therapy.

Emerging Infectious Diseases, Aug 1, 2011

We determined the seroprevalence of hepatitis E virus (HEV) in persons in 2 rural communities in ... more We determined the seroprevalence of hepatitis E virus (HEV) in persons in 2 rural communities in southeastern Bolivia and the presence of HEV in human and swine fecal samples. HEV seroprevalence was 6.3%, and HEV genotype 3 strains with high sequence homology were detected.

Archives of virology, Jan 9, 2015

Foot-and-mouth disease (FMD) is a livestock disease that has serious economic repercussions. Here... more Foot-and-mouth disease (FMD) is a livestock disease that has serious economic repercussions. Here, we report the laboratory results for samples from suspected outbreaks that were sent for confirmation of FMD in Pakistan. From January 2010 to December 2011, 132 suspected outbreaks were investigated, and samples from 58 out of the 76 outbreaks sent to the National Veterinary Laboratory (NVL) were positive. The highest proportion of positives were of serotype O (65.52 %), followed by serotype A (24.14 %) and serotype Asia-1 (10.35 %), whereas amongst the samples sent to the World Reference Laboratory, Pirbright, UK (WRL), samples from 48 out of 56 outbreaks were confirmed to be FMD positive, with the following serotypes identified: O (56.25 %), Asia-1 (37.50 %) and A (6.25 %). The outbreaks affected cattle, buffalo and mixed (cattle and buffalo) herds at rates of 91, 70 and 76 %, respectively. The trend of positive outbreaks was higher in the months of winter and late spring (November ...

Veterinary parasitology, Jan 15, 2006

There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers we... more There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers were validated under different DNA extraction methods and study designs leading to heterogeneity of results. The objective of the present study was to validate PCR as a diagnostic test for T. vivax trypanosomosis by means of determining the test sensitivity of different published specific primers with different sample preparations. Four different DNA extraction methods were used to test the sensitivity of PCR with four different primer sets. DNA was extracted directly from whole blood samples, blood dried on filter papers or blood dried on FTA cards. The results showed that the sensitivity of PCR with each primer set was highly dependant of the sample preparation and DNA extraction method. The highest sensitivities for all the primers tested were determined using DNA extracted from whole blood samples, while the lowest sensitivities were obtained when DNA was extracted from filter paper pr...

The American journal of tropical medicine and hygiene, 1998

The factors influencing the risk of acquisition of Helicobacter pylori infection are not well est... more The factors influencing the risk of acquisition of Helicobacter pylori infection are not well established. One hundred four children (0-17 years of age) requiring an endoscopy for the evaluation of gastrointestinal symptoms had demographic and dietary data collected and biopsy specimens of the gastric antrum stained for the identification of H. pylori. The 52 (50%) infected subjects were significantly older than the uninfected ones with no difference in gender, crowding, source of drinking water, or exposure to domestic animals. Increased prevalence of infection was associated with increased consumption of food from street vendors, and decreased consumption of fruits in the subgroup that denied consuming food from street vendors. No association was found with consumption of fish, chicken, beef, beans, vegetables, rice, cheese, milk, and unboiled water. These findings support the role of food prepared under unhygienic conditions as a probable mechanism of transmission of H. pylori in...

Vaccine, 2014

The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance ac... more The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance activities such as clinical inspections (CI) and serological monitoring. New evidence to refine current surveillance guidelines has been provided by evaluating (1) the diagnostic performance of CI and serological tests for detection of FMD virus (FMDV) non-structural proteins (NSP), and (2) the within-herd transmission of the virus in partially immune cattle. Data came from 23 affected herds during an epidemic of FMDV type O in Bolivia, in 2007. All cattle (n=957) in these herds were clinically inspected and serum samples were collected one month after the last animal with clinical signs was detected. Samples were tested for the presence of antibodies against NSP using the PANAFTOSA 3ABC-ELISA test and a subset of samples were tested using the enzyme-linked immunoelectrotransfer blot assay (EITB). Data from clinical and serological diagnoses were analysed using a Bayesian model. The sensitivity Se and specificity Sp of the tests, as well as the prevalence and the within-herd reproduction ratio R of FMDV were estimated. In addition, risk factors for infection were identified. The Se of CI, the 3ABC-ELISA and the EITB tests were estimated to be 0.30, 0.88 and 0.96 respectively. The estimated Sp, in the same order, were 0.88, 0.93 and 0.97. The within-herd prevalence of infected animals ranged from 0.04 to 0.91 and R ranged from 1.02 to 2.68. It was observed that cattle coming from areas with high vaccination coverage had a lower risk of becoming infected than home-bred cattle from the affected herds, where vaccination coverage was thought to be low. Although these estimates come from herds kept under specific conditions, they provide a reference for future surveillance design and can inform simulation models for surveillance and control of FMD in similar cattle populations.

Revista da Sociedade Brasileira de Medicina Tropical, 2010

We report a case of an immunocompetent Peruvian patient from the Andes with a one-month history o... more We report a case of an immunocompetent Peruvian patient from the Andes with a one-month history of meningoencephalitis. Cryptococcus gattii was identified from a cerebrospinal fluid culture through assimilation of D-proline and D-tryptophan as the single nitrogen source. Initially, the patient received intravenous antifungal therapy with amphotericin B. The patient was discharged 29 days after hospitalization and continued with oral fluconazole treatment for ten weeks. During this period, the patient showed clinical improvement with slight right-side residual weakness. Through this case report, we confirm the existence of this microorganism as an infectious agent in Peru.

Gynecologie Obstetrique & Fertilite - GYNECOL OBSTET FERTIL, 2006

With Ham, Leeuwenhoek discovered animalcules in human semen in 1677, without theoretical interpre... more With Ham, Leeuwenhoek discovered animalcules in human semen in 1677, without theoretical interpretations. Discussions focused on the respective role of ovum and animalcules during two centuries with erroneous doctrines. Modern ideas on status and origin of animalcules are associated with the development of the cell theory. Animalcules became spermatozoa. In 1875, Hertwig observed that the head of spermatozoon becomes a pronucleus and combines with the female pronucleus, thus establishing the concept that fertilization is the conjugation of two cells. During the first half of 20th century, endocrinology and genetics influenced management of infertile couples. Cryopreservation, analyses of ultrastructural morphology improved knowledges of normal and abnormal male gametes. In Vitro Fertilization and more IntraCytoplasmic Sperm Injection opened new views on the role of spermatozoa in human generation. Genetics and procreation were more and more so linked that each perspective of further...

Veterinary Parasitology, 2007

Trypanosomosis caused by Trypanosoma vivax has been a constraint for cattle production in the Bol... more Trypanosomosis caused by Trypanosoma vivax has been a constraint for cattle production in the Bolivian lowlands, since it was introduced in 1996. Flooded areas like the Bolivian Pantanal have a suitable environment for the presence and transmission of Salivarian trypanosomes and farmers from that region often report trypanosomosis-like problems on their farms. The objective of the present study, therefore, was to characterize the epidemiology of bovine trypanosomosis in the Bolivian Pantanal. In order to achieve this objective, 202 cattle from the province of Angel Sandoval and 209 cattle from the province of German Busch were randomly sampled (the Pantanal is located in both provinces). Twenty-nine farms in both provinces were visited, the farmers interviewed, and biologic samples collected from their cattle. Samples were submitted for parasitological and PCR evaluation and the prevalence of bovine trypanosomosis was estimated for each province. Laboratory results were correlated with the sampled animals packed cell volume (PCV) and body condition (BC) scores and the observed T. vivax parasites measured for morphometry analysis. Results from this study show differences in morphometric measures between T. vivax parasites from each province. Differences between provinces were also observed in the T. vivax-related disease situation. While in Angel Sandoval the PCV and BC of T. vivax-affected animals were significantly lower than those of the T. vivax-negative animals, in German Busch no differences were observed in the PCV and BC of T. vivax-positive or negative animals. Animal prevalence of T. vivax in Angel Sandoval was 27.79% (95% CI: 14.52-44.28) and in German Busch was 19.03% (95% CI: 9.19-30.75). The T. evansi animal prevalence in each province was 0.99% (95% CI: 0.27-2.99) and 5.71% (95% CI: 2.43-12.19), respectively. Based on questionnaire and laboratory results, it was concluded that trypanosomosis is a primary constraint for cattle production in the Bolivian Pantanal. #

Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly p... more Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly pathogenic avian influenza virus (HPAIv), which are lethal for most poultry species, can cause large epidemics and are a serious threat to public health. Thus, circulation of these LPAIv in poultry is undesirable. To date, these mutations cannot be reliably predicted and they can already take place within the first infected farm. Early detection and eradication of LPAI infected farms would minimise the probability of this mutations to happen. Because LPAI infections are associated with mild and unspecific clinical signs, detection of infected flocks is mainly based on serological surveillance.The goal of this thesis was to develop the framework of a serological surveillance programme for early detection of LPAI. Data of the current surveillance programmes in the European Union and the Netherlands were evaluated to quantify the risk of introduction of a LPAIv into the different poultry sec...

Scandinavian Journal of Immunology, 2011

Aggressive periodontitis (AgP) is a specific form of periodontal disease, with rapid destruction ... more Aggressive periodontitis (AgP) is a specific form of periodontal disease, with rapid destruction of the tissues supporting the teeth in otherwise young healthy individuals. We recently showed a higher frequency of the interleukin-4 (IL-4) -34TT and -590TT genotype in AgP patients compared to controls (P<0.05). Herein, we demonstrated that this specific IL-4 genotype exerts its function by increasing expression of IL-4 and STAT6, and producing higher concentrations of IL-4 in activated CD4+ cells of patients with AgP. In the present study, we investigated the effects of the IL-4-specific genotype on IL-13, IL-2 and IFN-γ expression and production in activated CD4+ cells of patients with AgP and healthy controls. Results revealed higher IFN-γ and IL-2 expression and significantly increased IL-13 production in the cells of the patients who were homozygous for the -34T and -590T alleles in comparison with the patients who were homozygous for the -34C and -590C alleles (P<0.05). Results of controls with the -34C and -590C alleles were similar to those of AgP with the same genotype. To our knowledge, the present study is the first to show an effect of the -34TT and -590TT genotype on IL-13 production. There is an increased production of IL-13 by the T cells of aggressive periodontitis patients with the IL-4 genotype.

Periodontology 2000, 2001

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

External root resorption can be divided into 3 categories: 1) progressive inflammatory resorption... more External root resorption can be divided into 3 categories: 1) progressive inflammatory resorption; 2) cervical resorption; and 3) replacement resorption. Cervical resorption is a not well recognized type of progressive external inflammatory resorption. It occurs after injury to the cervical attachment apparatus, mostly in the area of the cervical root surface (precementum) below the epithelial attachment. The present article describes an abnormal case of cervical resorption in a vital lateral maxillary incisor of a 27-year-old male patient. Endodontic treatment and subsequent periodontal plastic-esthetic surgery were performed. Reconstruction of the defect was achieved using mineral trioxide aggregate cement. After 2 years, the tooth showed no pathologic symptoms. The present case demonstrates a novel combined endodontic and periodontal treatment of an external root resorption.

Molecular Immunology, 2010

Aggressive periodontitis (AgP) is a severe periodontal disease characterized by rapid destruction... more Aggressive periodontitis (AgP) is a severe periodontal disease characterized by rapid destruction of the tissues supporting the teeth in otherwise healthy individuals. The frequency of the interleukin-4 homozygous −34TT and −590TT genotype was increased in patients in comparison with controls. This study aimed to test the functional effect of this specific genotype in AgP patients by analyzing gene expression of IL-4 and STAT6, and protein concentration of IL-4, in activated CD4+ T cells. Results revealed an increased IL-4 and STAT6 expression and IL-4 production in the cells of the patients who were homozygous for the −34T and −590T alleles in comparison with the patients who were homozygous for the −34C and −590C alleles (p < 0.05). These findings demonstrate that the IL-4 −34TT and −590TT genotype has a functional effect on T helper (Th) cells of patients with AgP, inducing increased expression of IL-4 and STAT6, and increased production of IL-4.

Journal of Periodontology, 2011

Journal of Periodontology, 2004

This multicenter, randomized trial compared enamel matrix derivative (EMD) with barrier membranes... more This multicenter, randomized trial compared enamel matrix derivative (EMD) with barrier membranes for the treatment of Class II mandibular furcations with regard to secondary outcomes. The influence of furcation morphology on the effectiveness of either treatment was also evaluated. Forty-eight patients (age range 28 to 73 years; 22 females, 26 males) with buccal Class II furcation involvements in both contralateral lower first or second molars were included. After initial periodontal treatment, defects were randomized to either EMD or bioabsorbable guided tissue regeneration (GTR) barrier. Study design and the results for the primary parameter were previously described. Results of the following secondary outcome variables are reported here: changes of the hard tissue boundaries describing the anatomical situation of the furcation defect and changes in the following clinical parameters between baseline and 14 months: plaque, level of gingival margin, probing depth, bleeding on probing, attachment level, and bone sounding at five sites/tooth at the buccal side. Descriptive statistics were applied for changes in clinical parameters and measurements of hard tissue boundaries. The differences observed under treatment with EMD or membrane were analyzed by means of the Wilcoxon two-sample test. The difference between the effect of the EMD and membrane treatment was estimated by means of the Hodges-Lehmann estimator. Overall, similar healing results were observed for both treatments. However, there was slightly more recession in the mid-furcation site following membrane treatment (P = 0.04). Additionally, different treatment effects could be detected for the distances from the stent or cemento-enamel junction (CEJ) to the buccal bone crest, mid-distal root (Pstent = 0.01; PCEJ = 0.07) and for the distance from the stent or CEJ to the buccal bone crest, mid-mesial root (Pstent = 0.01; PCEJ = 0.01). There was no measurable bone resorption in EMD sites, whereas a slight resorption occurred with membrane treatment. Furcation morphology at the time of surgery was not associated with clinical outcome, irrespective of the treatment. With regard to secondary outcome parameters, enamel matrix derivative treatment led to a similar regenerative result as the membrane procedure.

SSRN Electronic Journal, 2004

We modify the paper of Stahl (1989) on sequential consumer search in an oligopoly context by rela... more We modify the paper of Stahl (1989) on sequential consumer search in an oligopoly context by relaxing the assumption that consumers obtain the first price quotation for free. When all price quotations are costly to obtain, a new equilibrium arises where consumers randomize between not searching at all and searching for one price. The region of parameters for which this equilibrium exists becomes larger as the number of shoppers decreases and/or the number of firms increases. The comparative statics properties of this new equilibrium are interesting. In particular, the expected price increases as search cost decreases, and is constant in the number of shoppers and in the number of firms. We show that the Diamond result never obtains with truly costly search.

Anales de la Facultad de Medicina, 2013

Objetivos: Detectar el genoma proviral de HTLV-1 mediante el desarrollo de reacción en cadena de ... more Objetivos: Detectar el genoma proviral de HTLV-1 mediante el desarrollo de reacción en cadena de la polimerasa (PCR). Diseño: Descriptivo. Institución: D.A. Microbiología Médica, Facultad de Medicina, UNMSM. Participantes: Personas con y sin sospecha de HTLV-I. Principales medidas de resultados: detección de HTLV-1 mediante PCR. Resultados: El 71,4% de los pacientes con sospecha clínica de HTLV-I fue reactivo por métodos Inmunológico. Elisa HTLV I-II Biokit detectó 5 casos reactivos (X=2,359 ± DE: 0,7309); los dos casos con sospecha clínica de HTLV- I fueron no reactivos (DO: 0,007 y 0,04); los tres casos con antecedente clínico de estrongiloidiosis fueron no reactivos al Elisa (DO: 0,029, 0,001 y 0,00). El promedio de los sueros no reactivos con antecedente clínico de HTLV-1 y estrongiloidiosis fue 0,0154 ±0,018. En el grupo de voluntarios sanos, el promedio de las DO fue 0,0085 ± 0,0068. Al comparar los grupos, se observó que hubo diferencias significativas entre el grupo HTLV-1 y...

Anales de la Facultad de Medicina, 2013

Objetivos: Caracterizar las moléculas de respuesta humoral anti Paragonimus mexicanus/P. peruvian... more Objetivos: Caracterizar las moléculas de respuesta humoral anti Paragonimus mexicanus/P. peruvianus para diferenciar la infección en fase aguda y fase crónica, mediante la evaluación de la dinámica de la respuesta inmune. Diseño: Observacional, longitudinal. Institución: Instituto de Medicina Tropical Daniel A. Carrión, Facultad de Medicina, UNMSM Material biológico: Animales de experimentación. Principales medidas de resultados: Determinación de IgG e IgM anti Paragonimus. Resultados: Existió diferencia significativa de medias de la DO entre los grupos crónico y no infectados para los anticuerpos IgG anti ES de Paragonimus. Los anticuerpos IgM anti Paragonimus tuvieron una ligera elevación entre los días 7 a 20 post inoculación (pi), y una tendencia hacia la disminución entre los días 40 y 60 pi. Conclusiones: La dinámica de producción de anticuerpos IgG e IgM anti Paragonimus mediante Elisa indirecto, diferenció la fase aguda de la fase crónica, en los gatos inoculados.

Quintessence Publicacion Internacional De Odontologia, May 1, 2007

Resumen: El presente estudio aleatorizado multicéntrico tenía por objetivo comparar la eficacia t... more Resumen: El presente estudio aleatorizado multicéntrico tenía por objetivo comparar la eficacia terapéutica de las proteínas derivadas de la matriz del esmalte (Emdogain®, grupo experimental) con la de la regeneración tisular guiada por medio de membranas (Resolur ...

Http Dx Doi Org 10 1902 Jop 2004 75 8 1150, Jan 11, 2005

The objective of this multicenter, randomized trial was to compare enamel matrix derivative (EMD;... more The objective of this multicenter, randomized trial was to compare enamel matrix derivative (EMD; test) with barrier membranes (control) for the treatment of mandibular buccal Class II furcation defects. Forty-five patients with 90 comparable defects on contralateral molars were included. Defects were randomly assigned to EMD or bioabsorbable barrier membrane; the contralateral defect received the alternative treatment. Assessments at baseline and 8 and 14 months included gingival margin levels, probing depths, bleeding on probing, vertical attachment levels, and vertical bone sounding from a stent at five buccal sites/ tooth. Defect dimensions were recorded at surgery and during reentry at 14 months. Change of open horizontal furcation depth was the primary outcome variable. Adverse reactions and patient perceptions were also noted. Both treatment modalities led to significant clinical improvements. The median reduction of open horizontal furcation depth was 2.8 mm with the corresponding interquartile interval (1.5 mm, 3.5 mm) at test sites compared with 1.8 mm (1.0 mm, 2.8 mm) at control sites. The Hodges-Lehmann estimator of the advantage (reduction test versus control) was 0.75 mm (95% confidence interval [CI]: 0.125 mm, 1.375 mm, P = 0.033, Wilcoxon). The frequency of complete furcation closure was 8/45 (test) and 3/45 (control); partial closure, 27/45 in both groups; no change, 9/45 and 11/45, respectively; and deterioration, 1/45 and 4/45, respectively. The frequency of no pain or no swelling at 1 week post-surgery was 62% and 44%, respectively, at the test sites and 12% and 6% at the control sites. There was a significantly greater reduction in horizontal furcation depth and a comparatively lower incidence of postoperative pain/swelling following enamel matrix derivative compared to membrane therapy.

Emerging Infectious Diseases, Aug 1, 2011

We determined the seroprevalence of hepatitis E virus (HEV) in persons in 2 rural communities in ... more We determined the seroprevalence of hepatitis E virus (HEV) in persons in 2 rural communities in southeastern Bolivia and the presence of HEV in human and swine fecal samples. HEV seroprevalence was 6.3%, and HEV genotype 3 strains with high sequence homology were detected.

Archives of virology, Jan 9, 2015

Foot-and-mouth disease (FMD) is a livestock disease that has serious economic repercussions. Here... more Foot-and-mouth disease (FMD) is a livestock disease that has serious economic repercussions. Here, we report the laboratory results for samples from suspected outbreaks that were sent for confirmation of FMD in Pakistan. From January 2010 to December 2011, 132 suspected outbreaks were investigated, and samples from 58 out of the 76 outbreaks sent to the National Veterinary Laboratory (NVL) were positive. The highest proportion of positives were of serotype O (65.52 %), followed by serotype A (24.14 %) and serotype Asia-1 (10.35 %), whereas amongst the samples sent to the World Reference Laboratory, Pirbright, UK (WRL), samples from 48 out of 56 outbreaks were confirmed to be FMD positive, with the following serotypes identified: O (56.25 %), Asia-1 (37.50 %) and A (6.25 %). The outbreaks affected cattle, buffalo and mixed (cattle and buffalo) herds at rates of 91, 70 and 76 %, respectively. The trend of positive outbreaks was higher in the months of winter and late spring (November ...

Veterinary parasitology, Jan 15, 2006

There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers we... more There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers were validated under different DNA extraction methods and study designs leading to heterogeneity of results. The objective of the present study was to validate PCR as a diagnostic test for T. vivax trypanosomosis by means of determining the test sensitivity of different published specific primers with different sample preparations. Four different DNA extraction methods were used to test the sensitivity of PCR with four different primer sets. DNA was extracted directly from whole blood samples, blood dried on filter papers or blood dried on FTA cards. The results showed that the sensitivity of PCR with each primer set was highly dependant of the sample preparation and DNA extraction method. The highest sensitivities for all the primers tested were determined using DNA extracted from whole blood samples, while the lowest sensitivities were obtained when DNA was extracted from filter paper pr...

The American journal of tropical medicine and hygiene, 1998

The factors influencing the risk of acquisition of Helicobacter pylori infection are not well est... more The factors influencing the risk of acquisition of Helicobacter pylori infection are not well established. One hundred four children (0-17 years of age) requiring an endoscopy for the evaluation of gastrointestinal symptoms had demographic and dietary data collected and biopsy specimens of the gastric antrum stained for the identification of H. pylori. The 52 (50%) infected subjects were significantly older than the uninfected ones with no difference in gender, crowding, source of drinking water, or exposure to domestic animals. Increased prevalence of infection was associated with increased consumption of food from street vendors, and decreased consumption of fruits in the subgroup that denied consuming food from street vendors. No association was found with consumption of fish, chicken, beef, beans, vegetables, rice, cheese, milk, and unboiled water. These findings support the role of food prepared under unhygienic conditions as a probable mechanism of transmission of H. pylori in...

Vaccine, 2014

The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance ac... more The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance activities such as clinical inspections (CI) and serological monitoring. New evidence to refine current surveillance guidelines has been provided by evaluating (1) the diagnostic performance of CI and serological tests for detection of FMD virus (FMDV) non-structural proteins (NSP), and (2) the within-herd transmission of the virus in partially immune cattle. Data came from 23 affected herds during an epidemic of FMDV type O in Bolivia, in 2007. All cattle (n=957) in these herds were clinically inspected and serum samples were collected one month after the last animal with clinical signs was detected. Samples were tested for the presence of antibodies against NSP using the PANAFTOSA 3ABC-ELISA test and a subset of samples were tested using the enzyme-linked immunoelectrotransfer blot assay (EITB). Data from clinical and serological diagnoses were analysed using a Bayesian model. The sensitivity Se and specificity Sp of the tests, as well as the prevalence and the within-herd reproduction ratio R of FMDV were estimated. In addition, risk factors for infection were identified. The Se of CI, the 3ABC-ELISA and the EITB tests were estimated to be 0.30, 0.88 and 0.96 respectively. The estimated Sp, in the same order, were 0.88, 0.93 and 0.97. The within-herd prevalence of infected animals ranged from 0.04 to 0.91 and R ranged from 1.02 to 2.68. It was observed that cattle coming from areas with high vaccination coverage had a lower risk of becoming infected than home-bred cattle from the affected herds, where vaccination coverage was thought to be low. Although these estimates come from herds kept under specific conditions, they provide a reference for future surveillance design and can inform simulation models for surveillance and control of FMD in similar cattle populations.

Revista da Sociedade Brasileira de Medicina Tropical, 2010

We report a case of an immunocompetent Peruvian patient from the Andes with a one-month history o... more We report a case of an immunocompetent Peruvian patient from the Andes with a one-month history of meningoencephalitis. Cryptococcus gattii was identified from a cerebrospinal fluid culture through assimilation of D-proline and D-tryptophan as the single nitrogen source. Initially, the patient received intravenous antifungal therapy with amphotericin B. The patient was discharged 29 days after hospitalization and continued with oral fluconazole treatment for ten weeks. During this period, the patient showed clinical improvement with slight right-side residual weakness. Through this case report, we confirm the existence of this microorganism as an infectious agent in Peru.

Gynecologie Obstetrique & Fertilite - GYNECOL OBSTET FERTIL, 2006

With Ham, Leeuwenhoek discovered animalcules in human semen in 1677, without theoretical interpre... more With Ham, Leeuwenhoek discovered animalcules in human semen in 1677, without theoretical interpretations. Discussions focused on the respective role of ovum and animalcules during two centuries with erroneous doctrines. Modern ideas on status and origin of animalcules are associated with the development of the cell theory. Animalcules became spermatozoa. In 1875, Hertwig observed that the head of spermatozoon becomes a pronucleus and combines with the female pronucleus, thus establishing the concept that fertilization is the conjugation of two cells. During the first half of 20th century, endocrinology and genetics influenced management of infertile couples. Cryopreservation, analyses of ultrastructural morphology improved knowledges of normal and abnormal male gametes. In Vitro Fertilization and more IntraCytoplasmic Sperm Injection opened new views on the role of spermatozoa in human generation. Genetics and procreation were more and more so linked that each perspective of further...

Veterinary Parasitology, 2007

Trypanosomosis caused by Trypanosoma vivax has been a constraint for cattle production in the Bol... more Trypanosomosis caused by Trypanosoma vivax has been a constraint for cattle production in the Bolivian lowlands, since it was introduced in 1996. Flooded areas like the Bolivian Pantanal have a suitable environment for the presence and transmission of Salivarian trypanosomes and farmers from that region often report trypanosomosis-like problems on their farms. The objective of the present study, therefore, was to characterize the epidemiology of bovine trypanosomosis in the Bolivian Pantanal. In order to achieve this objective, 202 cattle from the province of Angel Sandoval and 209 cattle from the province of German Busch were randomly sampled (the Pantanal is located in both provinces). Twenty-nine farms in both provinces were visited, the farmers interviewed, and biologic samples collected from their cattle. Samples were submitted for parasitological and PCR evaluation and the prevalence of bovine trypanosomosis was estimated for each province. Laboratory results were correlated with the sampled animals packed cell volume (PCV) and body condition (BC) scores and the observed T. vivax parasites measured for morphometry analysis. Results from this study show differences in morphometric measures between T. vivax parasites from each province. Differences between provinces were also observed in the T. vivax-related disease situation. While in Angel Sandoval the PCV and BC of T. vivax-affected animals were significantly lower than those of the T. vivax-negative animals, in German Busch no differences were observed in the PCV and BC of T. vivax-positive or negative animals. Animal prevalence of T. vivax in Angel Sandoval was 27.79% (95% CI: 14.52-44.28) and in German Busch was 19.03% (95% CI: 9.19-30.75). The T. evansi animal prevalence in each province was 0.99% (95% CI: 0.27-2.99) and 5.71% (95% CI: 2.43-12.19), respectively. Based on questionnaire and laboratory results, it was concluded that trypanosomosis is a primary constraint for cattle production in the Bolivian Pantanal. #

Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly p... more Low pathogenic avian influenza virus (LPAIv) of H5 and H7 subtypes are able to mutate to highly pathogenic avian influenza virus (HPAIv), which are lethal for most poultry species, can cause large epidemics and are a serious threat to public health. Thus, circulation of these LPAIv in poultry is undesirable. To date, these mutations cannot be reliably predicted and they can already take place within the first infected farm. Early detection and eradication of LPAI infected farms would minimise the probability of this mutations to happen. Because LPAI infections are associated with mild and unspecific clinical signs, detection of infected flocks is mainly based on serological surveillance.The goal of this thesis was to develop the framework of a serological surveillance programme for early detection of LPAI. Data of the current surveillance programmes in the European Union and the Netherlands were evaluated to quantify the risk of introduction of a LPAIv into the different poultry sec...

Scandinavian Journal of Immunology, 2011

Aggressive periodontitis (AgP) is a specific form of periodontal disease, with rapid destruction ... more Aggressive periodontitis (AgP) is a specific form of periodontal disease, with rapid destruction of the tissues supporting the teeth in otherwise young healthy individuals. We recently showed a higher frequency of the interleukin-4 (IL-4) -34TT and -590TT genotype in AgP patients compared to controls (P&lt;0.05). Herein, we demonstrated that this specific IL-4 genotype exerts its function by increasing expression of IL-4 and STAT6, and producing higher concentrations of IL-4 in activated CD4+ cells of patients with AgP. In the present study, we investigated the effects of the IL-4-specific genotype on IL-13, IL-2 and IFN-γ expression and production in activated CD4+ cells of patients with AgP and healthy controls. Results revealed higher IFN-γ and IL-2 expression and significantly increased IL-13 production in the cells of the patients who were homozygous for the -34T and -590T alleles in comparison with the patients who were homozygous for the -34C and -590C alleles (P&lt;0.05). Results of controls with the -34C and -590C alleles were similar to those of AgP with the same genotype. To our knowledge, the present study is the first to show an effect of the -34TT and -590TT genotype on IL-13 production. There is an increased production of IL-13 by the T cells of aggressive periodontitis patients with the IL-4 genotype.

Periodontology 2000, 2001

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

External root resorption can be divided into 3 categories: 1) progressive inflammatory resorption... more External root resorption can be divided into 3 categories: 1) progressive inflammatory resorption; 2) cervical resorption; and 3) replacement resorption. Cervical resorption is a not well recognized type of progressive external inflammatory resorption. It occurs after injury to the cervical attachment apparatus, mostly in the area of the cervical root surface (precementum) below the epithelial attachment. The present article describes an abnormal case of cervical resorption in a vital lateral maxillary incisor of a 27-year-old male patient. Endodontic treatment and subsequent periodontal plastic-esthetic surgery were performed. Reconstruction of the defect was achieved using mineral trioxide aggregate cement. After 2 years, the tooth showed no pathologic symptoms. The present case demonstrates a novel combined endodontic and periodontal treatment of an external root resorption.

Molecular Immunology, 2010

Aggressive periodontitis (AgP) is a severe periodontal disease characterized by rapid destruction... more Aggressive periodontitis (AgP) is a severe periodontal disease characterized by rapid destruction of the tissues supporting the teeth in otherwise healthy individuals. The frequency of the interleukin-4 homozygous −34TT and −590TT genotype was increased in patients in comparison with controls. This study aimed to test the functional effect of this specific genotype in AgP patients by analyzing gene expression of IL-4 and STAT6, and protein concentration of IL-4, in activated CD4+ T cells. Results revealed an increased IL-4 and STAT6 expression and IL-4 production in the cells of the patients who were homozygous for the −34T and −590T alleles in comparison with the patients who were homozygous for the −34C and −590C alleles (p < 0.05). These findings demonstrate that the IL-4 −34TT and −590TT genotype has a functional effect on T helper (Th) cells of patients with AgP, inducing increased expression of IL-4 and STAT6, and increased production of IL-4.

Journal of Periodontology, 2011

Journal of Periodontology, 2004

This multicenter, randomized trial compared enamel matrix derivative (EMD) with barrier membranes... more This multicenter, randomized trial compared enamel matrix derivative (EMD) with barrier membranes for the treatment of Class II mandibular furcations with regard to secondary outcomes. The influence of furcation morphology on the effectiveness of either treatment was also evaluated. Forty-eight patients (age range 28 to 73 years; 22 females, 26 males) with buccal Class II furcation involvements in both contralateral lower first or second molars were included. After initial periodontal treatment, defects were randomized to either EMD or bioabsorbable guided tissue regeneration (GTR) barrier. Study design and the results for the primary parameter were previously described. Results of the following secondary outcome variables are reported here: changes of the hard tissue boundaries describing the anatomical situation of the furcation defect and changes in the following clinical parameters between baseline and 14 months: plaque, level of gingival margin, probing depth, bleeding on probing, attachment level, and bone sounding at five sites/tooth at the buccal side. Descriptive statistics were applied for changes in clinical parameters and measurements of hard tissue boundaries. The differences observed under treatment with EMD or membrane were analyzed by means of the Wilcoxon two-sample test. The difference between the effect of the EMD and membrane treatment was estimated by means of the Hodges-Lehmann estimator. Overall, similar healing results were observed for both treatments. However, there was slightly more recession in the mid-furcation site following membrane treatment (P = 0.04). Additionally, different treatment effects could be detected for the distances from the stent or cemento-enamel junction (CEJ) to the buccal bone crest, mid-distal root (Pstent = 0.01; PCEJ = 0.07) and for the distance from the stent or CEJ to the buccal bone crest, mid-mesial root (Pstent = 0.01; PCEJ = 0.01). There was no measurable bone resorption in EMD sites, whereas a slight resorption occurred with membrane treatment. Furcation morphology at the time of surgery was not associated with clinical outcome, irrespective of the treatment. With regard to secondary outcome parameters, enamel matrix derivative treatment led to a similar regenerative result as the membrane procedure.