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Papers by Wayne Mohammed

Revista panamericana de salud pública (Impresa), Apr 1, 2013

Objective. To determine the relative contribution of known high-risk human papillomavirus (HPV) g... more Objective. To determine the relative contribution of known high-risk human papillomavirus (HPV) genotypes to the occurrence of cervical cancers in Trinidad. Methods. The distribution of HPV genotypes in cases of invasive cervical squamous cell carcinoma in Trinidad was investigated. This study was a follow-up to an investigation of HPV genotypes in 310 nonsymptomatic women in Trinidad. The latter study showed that cervical HPV prevalence and heterogeneity of genotypes were high in the study population; notably, the genotypes targeted by the available HPV prophylactic vaccines were not the most common types. Results. The current study of 85 cases of invasive cervical squamous cell carcinomas demonstrated that the previously observed heterogeneity in HPV genotype distribution is lost in cases of invasive cervical cancer, with the vaccine-targeted HPV types HPV 16 and HPV 18 becoming the most prevalent. Conclusions. HPV 16 and HPV 18 were the primary HPV genotypes associated with cases of invasive squamous cell carcinoma in the current Trinidad study. This strong association leads us to conclude that the HPV vaccines targeting HPV 16 and HPV 18 may contribute to reducing the cervical cancer burden in Trinidad.

The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601... more The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601 of the HIV gp41 and fragments 308 331 and 421 438 of the HIV gp120 from the human immunodeficiency virus (HIV) in layer hens. Keyhole limpet hemocynin (KLH) was conjugated to HIV synthetic peptides by the glutaraldehyde method after they were dimerized by cysteine oxidation with dimethyl sulfide. Two healthy brown Leghorn layer hens (per immunogen) were injected intramuscularly on the breasts with KLH peptide conjugated vaccines. They were immunized on days 0,21,45 and 60. Enzyme linked immunosorbent assays (ELISA) were used to test for anti HIV antibodies and there was a statistical significance in the mean of optical density readings between pre immunized and post immunized animals, proving the formation of specific antibodies. These molecules can potentially be used as therapeutic agents or diagnostic reagents. The limitations of this investigation were the small number of cases, vir...

International Journal of Gynecology & Obstetrics, 2009

Cervical cancer is the second most common cancer affecting women worldwide [1], with persistent i... more Cervical cancer is the second most common cancer affecting women worldwide [1], with persistent infection by high-risk human papillomavirus (HPV) having an important role in cervical carcinogenesis [2]. Knowledge of HPV genotypes associated with invasive cervical carcinoma is necessary for determining the impact of new HPV vaccines on the incidence of these lesions. An updated meta-analysis of the worldwide distribution of HPV types associated with both invasive cervical cancer and high-grade squamous intraepithelial lesions was recently published [3]. A total of 14 595 cases of invasive cervical cancer revealed HPV 16 to be the most common type on all continents, with HPV 18 the second most common. Types 31, 33, 35, 45, 52, and 58 were the next most common types, although there was regional variation in the relative importance of each of these 6 types. Data from the Middle East were scarce; thus, the objective of the present study was to determine the HPV genotypes involved in invasive cervical cancer in Jordan. The archives of the Pathology Department at King Hussein Cancer Center, Amman, Jordan, were searched for cases of invasive cervical cancer; all cases accessioned at the time of diagnosis between 2003 and 2007, and with available paraffin blocks, were analyzed. Using the Extra DNA Tissue kit (Sacace Biotechnologies, Como, Italy) according to the manufacturer's instructions, DNA was extracted from the paraffin blocks. The adequacy and the integrity of extracted DNA were assessed via spectrophotometry and polymerase chain reaction (PCR) for the gene encoding GAPDH. An HPV typing kit (Sacace Biotechnologies, Como, Italy) containing 4 mixes of multiple primers-types 16, 31, 33, and 35; types 18, 39, 45, and 59; types 52, 56, 58, and 66; and types 6 and 11-was used. Amplification was followed by electrophoresis and band identification using an ultraviolet transilluminator. Negative results were invalidated if the internal control (the gene encoding β-globin) was absent. Positive and negative controls were included in each run. Forty-eight cases of invasive cervical cancer with 54 paraffin blocks available were identified; 7 cases failed to produce adequate DNA. Patient age in the remaining 41 cases ranged from 37 to 80 years, with Cervical cancer Genotypes Human papillomavirus Jordan

Revista Panamericana de Salud Pública

Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort o... more Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort of 310 sexually active women in Trinidad, West Indies. Cervical samples were collected with Ayre's spatulas and endocervical brushes. Samples were used for the conventional Papanicolaou test and for determining HPV genotypes by amplification of a section of the viral L1 gene, followed by DNA sequencing and probe hybridization. HPV infections were identified in 126 of 310 (40.6%) women. Of them, 83 (65.8%) were infected with high-risk HPV, 16 (12.7%) with low-risk HPV, and 27 (21.4%) with HPV types of unknown risk. HPV 52 (12.7%) was the most frequently occurring high-risk type, followed by HPV 66 (10.3%), HPV 16 (9.5%), and HPV 18 (8.6%). High-risk types HPV 16 and HPV 66 were each found in 3 (20.0%) and HPV 18 was found in 1 (6.6%) of the 15 women with abnormal cytology. Cervical HPV prevalence and heterogeneity of HPV genotypes are high in this Trinidad cohort. The relative importan...

Journal of Cancer Research and Therapeutics

Objectives: The objective of the evaluate was to study and determine the usefulness of immunohist... more Objectives: The objective of the evaluate was to study and determine the usefulness of immunohistochemistry (IHC) staining in neoplastic lung lesions. Materials and Methods: We evaluated seven IHC stains in fifty lung cancers that included adenocarcinoma (AC), squamous cell carcinoma (SCC), small cell carcinoma, and carcinoid tumors. Results: P63 was expressed in all the cases of SCCs and thyroid transcription factor-1 (TTF-1) was expressed in all cases of ACs. CK 5/6 was expressed in 77.77% of SCCs and CK 7 was expressed in 92.59% of ACs. Synaptophysin and chromogranin-A were expressed in 100% of neuroendocrine (NE) carcinomas. Conclusion: P63 and TTF-1 are sensitive markers for SCCs and ACs. Synaptophysin and Chromogranin-A are sensitive markers for NE carcinomas.

Journal of Chromatography & Separation Techniques, 2013

By using trichloroacetic acid (TCA) precipitation to separate egg yolk proteins, mainly IgY was d... more By using trichloroacetic acid (TCA) precipitation to separate egg yolk proteins, mainly IgY was demonstrated that this procedure yield twice more IgY that its counterpart polyethylene glycol (PEG). An ELISA demonstrated that it does not affect the functionality of the IgY molecule. The TCA precipitation procedure provides an efficient and rapid way to purify IgY antibody. It can be used for large scale production of high quality IgY.

Journal of Vaccines and Vaccination, 2013

The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601... more The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601 of the HIV gp41 and fragments 308 331 and 421 438 of the HIV gp120 from the human immunodeficiency virus (HIV) in layer hens. Keyhole limpet hemocynin (KLH) was conjugated to HIV synthetic peptides by the glutaraldehyde method after they were dimerized by cysteine oxidation with dimethyl sulfide. Two healthy brown Leghorn layer hens (per immunogen) were injected intramuscularly on the breasts with KLH peptide conjugated vaccines. They were immunized on days 0,21,45 and 60. Enzyme linked immunosorbent assays (ELISA) were used to test for anti HIV antibodies and there was a statistical significance in the mean of optical density readings between pre immunized and post immunized animals, proving the formation of specific antibodies. These molecules can potentially be used as therapeutic agents or diagnostic reagents. The limitations of this investigation were the small number of cases, vir...

Journal of Chromatography & Separation Techniques, 2015

A mule is the off-spring (F1 hybrid) of two equine species: a male donkey and a female horse. Lit... more A mule is the off-spring (F1 hybrid) of two equine species: a male donkey and a female horse. Little is known about the immune system of the mule. In this investigation we isolated and characterized molecularly the mule IgG that was purified by Staphylococcal protein A (SpA) affinity chromatography, and then the purified IgG was further study by SDS-PAGE and enzyme-linked immunosorbent assay that concluded that the intact mule IgG has a molecular weight of 150 kDa.

Journal of Chromatography & Separation Techniques, 2013

The aim of this preliminary study was to investigate the presence of proteins in the tissue fluid... more The aim of this preliminary study was to investigate the presence of proteins in the tissue fluids of the sea mussel Isognomonalatus. Protein extraction was done by the chloroform-cold ethanol technique. Immunization for production of antibody to be used as reagents in Western blotting, assessment of the protein concentration by the Bradford method, protein characterization by native polyacrylamide gel electrophoresis (PAGE) were also performed as a part of the methodology of this study. The results showed a protein content of 65 mg/ml in tissue fluids and a protein band approximately of 220 kDa in PAGE that was further confirmed by the Western blotting. Future work should investigate the structure and function of the proteins separated from the tissue fluids and we considered it as a limitation of this investigation. The sea bivalve literature is scanty. However the limitation of this work we still can conclude that there are high molecular weight proteins in large concentrations i...

Our aim was to provide information about the production of Egg White Immunoglobulin (EWIg) with s... more Our aim was to provide information about the production of Egg White Immunoglobulin (EWIg) with specificity to Staphylococcal protein-A, a surface antigen of Staphylococcus aureus and to study the inhibition of this bacterium growth in pre- and post-immunized hens. A sandwich Enzyme-Immunosorbent Assay (ELISA) showed a large concentration of anti-SpA antibodies in the eggs from hens immunized with protein A. The titer of these antibodies was at least 5 to 6-folds of that of the eggs from pre-immunized hens 10 days post-immunization. Inhibition of the growth of S. aureus by anti-SpA antibodies purified by SpA-affinity chromatography (PURE-1A) was observed in laying hens vaccinated. Growth of the bacteria in blood agar plates occurred in antibody samples from preimmunized laying hens only. Inhibition of the agglutination of SpA-bearing Staphylococcus aureus cells by purified anti-SpA antibodies was observed in vitro. The authors are not aware of previous studies of the primary immune ...

Journal of Veterinary Science and Technology, 2015

Objective: To purify IgG molecules from several species by SpA-affinity chromatography and to stu... more Objective: To purify IgG molecules from several species by SpA-affinity chromatography and to study the interactions of mammalian IgGs with a peroxidase-labelled SpL, SpA and SpG conjugate (SPLAG-HRP) in an enzyme-linked immunosorbent assay (ELISA). Materials and methods: The periodate method described by Nakane and Kawoi was used to prepare the SPLAG-HRP conjugate. The 10% non-denaturing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of sera and purified immunoglobulins was carried out to characterize molecularly the purified IgGs. The chicken IgY fraction was isolated by the chloroform-polyethylene glycol (PEG) method for its use as a negative control in the ELISA that was used to determine the affinity of different immunoglobulins to a SPLAG-HRP conjugate. Results: The SpA-affinity chromatography and the 10% non-denaturing SDS-PAGE of sera and purified immunoglobulins (IgGs) were useful separation techniques. Most purified IgGs interacted moderately with th...

Journal of analytical and bioanalytical techniques, 2015

2Biochemistry Section, Department of Basic Medical Sciences, The University of the West Indies, M... more 2Biochemistry Section, Department of Basic Medical Sciences, The University of the West Indies, Mona Campus, Jamaica, West Indies *Corresponding author: Angel Justiz-Vaillant, Pathology and Microbiology Unit, Department of Para-Clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies; Tel: +868-773-5914; E-mail: angel.vaillant@sta.uwi.edu

Angel Alberto Justiz Vaillant1*, Wayne Mohammed1, Sehlule Vuma1 and Norma Anderson2 1Department o... more Angel Alberto Justiz Vaillant1*, Wayne Mohammed1, Sehlule Vuma1 and Norma Anderson2 1Department of Para-clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, Trinidad and Tobago, West Indies 2Department of Basic Medical Sciences, The University of the West Indies, Mona campus, Jamaica, West Indies *Corresponding author: Angel Alberto Justiz Vaillant, Department of Para-clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, Trinidad and Tobago, West Indies, E-mail: avail4883@gmail.com

Journal of Marine Science: Research & Development, 2014

The aim of this preliminary study was to investigate the presence of proteins in the tissue fluid... more The aim of this preliminary study was to investigate the presence of proteins in the tissue fluids of the sea mussel Isognomon alatus. Protein extraction was done by the chloroform-cold ethanol technique. Immunization for production of antibody to be used as reagents in Western blotting, assessment of the protein concentration by the Bradford method, protein characterization by native polyacrylamide gel electrophoresis (PAGE) were also performed as a part of the methodology of this study. The results showed a protein content of 65 mg/ml in tissue fluids and a protein band approximately of 220 kDa in PAGE that was further confirmed by the Western blotting. Future work should investigate the structure and function of the proteins separated from the tissue fluids and we considered it as a limitation of this investigation. The sea bivalve literature is scanty. However the limitation of this work we still can conclude that there are high molecular weight proteins in large concentrations ...

Immunome Research, 2018

Streptococcal protein-G (SpG), type III bacterial Fc receptor, is a small globular protein produc... more Streptococcal protein-G (SpG), type III bacterial Fc receptor, is a small globular protein produced by several Streptococcal species and it is composed of two or three nearly identical domains, each of 55 amino acids. Streptococcal protein G has been shown to have high binding affinity to sera from various mammalian species including rabbit, human, pig, goat, sheep, cow and many other animal species. Of concern are patients with invasive infections by Streptococcus spp, where large amount of secreted SpG could interfere with the outcome of the gel technique by getting false negative tests. It has been shown and reported that the bacterial protein SpA was already found to inhibit the Coomb's test. We hypothesize that SpG as well as many other immunoglobulin-binding bacterial proteins with binding affinity to human IgG could cause false negative results in patients with bacteraemia. With the intention of proving this hypothesis we conducted two sets of experiments, which proved that SpG has the potential of inhibiting the gel test for the detection of sensitized erythrocytes in vitro. We concluded that is important to exercise caution, when evaluating a result of gel technique in patients with septicemia caused by SpG-producer Streptococci. The experiments used in this research were novel modifications of existent techniques and they proved reliable in demonstrating our hypothesis.

BMJ Case Reports, 2018

this case presents a woman in her early 20s who died after the sudden onset of chest pain. Five y... more this case presents a woman in her early 20s who died after the sudden onset of chest pain. Five years earlier, she was investigated for a cardiac murmur during pregnancy and an echocardiogram revealed a 6.0×3.0 cm blood-filled sac compressing the left atrium and anterolateral aspect of the left ventricle with communication to the aortic root. she later had a Ct scan of the chest with contrast, which showed aneurysmal dilatation of the left main coronary artery. she was placed on aspirin but defaulted from clinic 11 months post partum. at autopsy, a left coronary aneurysmal sac measuring 10.0×9.0 cm. was identified with a rupture measuring 7.0 cm in length and the pericardial sac contained 900 mL of blood with clots. the cause of death was cardiac tamponade secondary to rupture of the coronary artery aneurysm.

Journal of surgical case reports, 2018

Splenic artery aneurysms (SAAs) are an extremely rare cause of asymptomatic massive lower gastroi... more Splenic artery aneurysms (SAAs) are an extremely rare cause of asymptomatic massive lower gastrointestinal bleeding with less than a handful of patients surviving such a presentation. A 24-year-old female presented in shock after multiple episodes of massive rectal bleeding. Imaging revealed a heterogeneous mass arising from the tail of the pancreas eroding into the splenic flexure of the colon. Further episodes of bleeding led to an exploratory laparotomy. Intraoperatively, a suspected neoplastic process arising from the tail of the pancreas with contiguous involvement of the splenic flexure of the colon and the greater curvature of the stomach was noted. Distal pancreaticosplenectomy, gastric wedge resection with segmental colectomy and primary anastomosis were performed. Histology revealed a SAA with rupture into the colon. This case report shows that en-bloc resection of a ruptured SAA can be performed with success in the emergency setting.

International journal of surgery case reports, Jan 4, 2017

Phyllodes tumors (PTs) of the breast are extremely rare accounting for less than 1% of all breast... more Phyllodes tumors (PTs) of the breast are extremely rare accounting for less than 1% of all breast tumors globally. Case records at the Trinidad and Tobago Cancer Registry show that only 0.003% of the reported breast cancer cases between 1995 and 2009 were PTs. We report a 45-year-old woman who presented with swelling of the left breast. Ultrasound, mammogram and computed tomography imaging confirmed the presence of a mass in the right upper inner quadrant of the left breast. A biopsy revealed features supportive of a benign phyllodes tumor. A wide local excision was performed with the removal of a 19×11×10cm mass. Histopathological analysis revealed features consistent with malignant phyllodes tumor. A complete mastectomy of the left breast was subsequently performed. Follow up over a 5-year period did not reveal any evidence of local recurrence or residual disease. To the best of our knowledge, this is the first case report of a malignant PT from the Caribbean and Latin America. Ph...

International journal of surgery case reports, Jan 7, 2017

Pelvic exenteration (PE) is an ultra-radical surgical procedure characterized by the en bloc rese... more Pelvic exenteration (PE) is an ultra-radical surgical procedure characterized by the en bloc resection of the pelvic organs. In this case series, we report retrospectively on four patients who underwent PE in Trinidad and Tobago from 2012 to 2016. One male patient had rectal cancer while one each of three women had cervical, colon, or rectal cancer. Early postoperative complications (≤30days) occurred in all patients, while late complications (>30days) occurred in one patient (Grade 1 - Clavien-Dindo classification). Disease recurrence occurred in 50% of patients, and the median overall survival was 8 months (range, 4-15 months). There are many inherent challenges to conducting such major procedures in developing countries, including inadequate blood product supplies, intensive care unit beds, and pre- and post-operative support services. With increased surgical capacity and support infrastructure, hospitals in these regions would be equipped to perform PEs with better outcomes. ...

Revista panamericana de salud pública (Impresa), Apr 1, 2013

Objective. To determine the relative contribution of known high-risk human papillomavirus (HPV) g... more Objective. To determine the relative contribution of known high-risk human papillomavirus (HPV) genotypes to the occurrence of cervical cancers in Trinidad. Methods. The distribution of HPV genotypes in cases of invasive cervical squamous cell carcinoma in Trinidad was investigated. This study was a follow-up to an investigation of HPV genotypes in 310 nonsymptomatic women in Trinidad. The latter study showed that cervical HPV prevalence and heterogeneity of genotypes were high in the study population; notably, the genotypes targeted by the available HPV prophylactic vaccines were not the most common types. Results. The current study of 85 cases of invasive cervical squamous cell carcinomas demonstrated that the previously observed heterogeneity in HPV genotype distribution is lost in cases of invasive cervical cancer, with the vaccine-targeted HPV types HPV 16 and HPV 18 becoming the most prevalent. Conclusions. HPV 16 and HPV 18 were the primary HPV genotypes associated with cases of invasive squamous cell carcinoma in the current Trinidad study. This strong association leads us to conclude that the HPV vaccines targeting HPV 16 and HPV 18 may contribute to reducing the cervical cancer burden in Trinidad.

The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601... more The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601 of the HIV gp41 and fragments 308 331 and 421 438 of the HIV gp120 from the human immunodeficiency virus (HIV) in layer hens. Keyhole limpet hemocynin (KLH) was conjugated to HIV synthetic peptides by the glutaraldehyde method after they were dimerized by cysteine oxidation with dimethyl sulfide. Two healthy brown Leghorn layer hens (per immunogen) were injected intramuscularly on the breasts with KLH peptide conjugated vaccines. They were immunized on days 0,21,45 and 60. Enzyme linked immunosorbent assays (ELISA) were used to test for anti HIV antibodies and there was a statistical significance in the mean of optical density readings between pre immunized and post immunized animals, proving the formation of specific antibodies. These molecules can potentially be used as therapeutic agents or diagnostic reagents. The limitations of this investigation were the small number of cases, vir...

International Journal of Gynecology & Obstetrics, 2009

Cervical cancer is the second most common cancer affecting women worldwide [1], with persistent i... more Cervical cancer is the second most common cancer affecting women worldwide [1], with persistent infection by high-risk human papillomavirus (HPV) having an important role in cervical carcinogenesis [2]. Knowledge of HPV genotypes associated with invasive cervical carcinoma is necessary for determining the impact of new HPV vaccines on the incidence of these lesions. An updated meta-analysis of the worldwide distribution of HPV types associated with both invasive cervical cancer and high-grade squamous intraepithelial lesions was recently published [3]. A total of 14 595 cases of invasive cervical cancer revealed HPV 16 to be the most common type on all continents, with HPV 18 the second most common. Types 31, 33, 35, 45, 52, and 58 were the next most common types, although there was regional variation in the relative importance of each of these 6 types. Data from the Middle East were scarce; thus, the objective of the present study was to determine the HPV genotypes involved in invasive cervical cancer in Jordan. The archives of the Pathology Department at King Hussein Cancer Center, Amman, Jordan, were searched for cases of invasive cervical cancer; all cases accessioned at the time of diagnosis between 2003 and 2007, and with available paraffin blocks, were analyzed. Using the Extra DNA Tissue kit (Sacace Biotechnologies, Como, Italy) according to the manufacturer's instructions, DNA was extracted from the paraffin blocks. The adequacy and the integrity of extracted DNA were assessed via spectrophotometry and polymerase chain reaction (PCR) for the gene encoding GAPDH. An HPV typing kit (Sacace Biotechnologies, Como, Italy) containing 4 mixes of multiple primers-types 16, 31, 33, and 35; types 18, 39, 45, and 59; types 52, 56, 58, and 66; and types 6 and 11-was used. Amplification was followed by electrophoresis and band identification using an ultraviolet transilluminator. Negative results were invalidated if the internal control (the gene encoding β-globin) was absent. Positive and negative controls were included in each run. Forty-eight cases of invasive cervical cancer with 54 paraffin blocks available were identified; 7 cases failed to produce adequate DNA. Patient age in the remaining 41 cases ranged from 37 to 80 years, with Cervical cancer Genotypes Human papillomavirus Jordan

Revista Panamericana de Salud Pública

Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort o... more Human papillomavirus (HPV) genotypes and their relative prevalences were determined in a cohort of 310 sexually active women in Trinidad, West Indies. Cervical samples were collected with Ayre's spatulas and endocervical brushes. Samples were used for the conventional Papanicolaou test and for determining HPV genotypes by amplification of a section of the viral L1 gene, followed by DNA sequencing and probe hybridization. HPV infections were identified in 126 of 310 (40.6%) women. Of them, 83 (65.8%) were infected with high-risk HPV, 16 (12.7%) with low-risk HPV, and 27 (21.4%) with HPV types of unknown risk. HPV 52 (12.7%) was the most frequently occurring high-risk type, followed by HPV 66 (10.3%), HPV 16 (9.5%), and HPV 18 (8.6%). High-risk types HPV 16 and HPV 66 were each found in 3 (20.0%) and HPV 18 was found in 1 (6.6%) of the 15 women with abnormal cytology. Cervical HPV prevalence and heterogeneity of HPV genotypes are high in this Trinidad cohort. The relative importan...

Journal of Cancer Research and Therapeutics

Objectives: The objective of the evaluate was to study and determine the usefulness of immunohist... more Objectives: The objective of the evaluate was to study and determine the usefulness of immunohistochemistry (IHC) staining in neoplastic lung lesions. Materials and Methods: We evaluated seven IHC stains in fifty lung cancers that included adenocarcinoma (AC), squamous cell carcinoma (SCC), small cell carcinoma, and carcinoid tumors. Results: P63 was expressed in all the cases of SCCs and thyroid transcription factor-1 (TTF-1) was expressed in all cases of ACs. CK 5/6 was expressed in 77.77% of SCCs and CK 7 was expressed in 92.59% of ACs. Synaptophysin and chromogranin-A were expressed in 100% of neuroendocrine (NE) carcinomas. Conclusion: P63 and TTF-1 are sensitive markers for SCCs and ACs. Synaptophysin and Chromogranin-A are sensitive markers for NE carcinomas.

Journal of Chromatography & Separation Techniques, 2013

By using trichloroacetic acid (TCA) precipitation to separate egg yolk proteins, mainly IgY was d... more By using trichloroacetic acid (TCA) precipitation to separate egg yolk proteins, mainly IgY was demonstrated that this procedure yield twice more IgY that its counterpart polyethylene glycol (PEG). An ELISA demonstrated that it does not affect the functionality of the IgY molecule. The TCA precipitation procedure provides an efficient and rapid way to purify IgY antibody. It can be used for large scale production of high quality IgY.

Journal of Vaccines and Vaccination, 2013

The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601... more The aim of this preliminary study was to produce anti HIV antibodies against the fragment 579 601 of the HIV gp41 and fragments 308 331 and 421 438 of the HIV gp120 from the human immunodeficiency virus (HIV) in layer hens. Keyhole limpet hemocynin (KLH) was conjugated to HIV synthetic peptides by the glutaraldehyde method after they were dimerized by cysteine oxidation with dimethyl sulfide. Two healthy brown Leghorn layer hens (per immunogen) were injected intramuscularly on the breasts with KLH peptide conjugated vaccines. They were immunized on days 0,21,45 and 60. Enzyme linked immunosorbent assays (ELISA) were used to test for anti HIV antibodies and there was a statistical significance in the mean of optical density readings between pre immunized and post immunized animals, proving the formation of specific antibodies. These molecules can potentially be used as therapeutic agents or diagnostic reagents. The limitations of this investigation were the small number of cases, vir...

Journal of Chromatography & Separation Techniques, 2015

A mule is the off-spring (F1 hybrid) of two equine species: a male donkey and a female horse. Lit... more A mule is the off-spring (F1 hybrid) of two equine species: a male donkey and a female horse. Little is known about the immune system of the mule. In this investigation we isolated and characterized molecularly the mule IgG that was purified by Staphylococcal protein A (SpA) affinity chromatography, and then the purified IgG was further study by SDS-PAGE and enzyme-linked immunosorbent assay that concluded that the intact mule IgG has a molecular weight of 150 kDa.

Journal of Chromatography & Separation Techniques, 2013

The aim of this preliminary study was to investigate the presence of proteins in the tissue fluid... more The aim of this preliminary study was to investigate the presence of proteins in the tissue fluids of the sea mussel Isognomonalatus. Protein extraction was done by the chloroform-cold ethanol technique. Immunization for production of antibody to be used as reagents in Western blotting, assessment of the protein concentration by the Bradford method, protein characterization by native polyacrylamide gel electrophoresis (PAGE) were also performed as a part of the methodology of this study. The results showed a protein content of 65 mg/ml in tissue fluids and a protein band approximately of 220 kDa in PAGE that was further confirmed by the Western blotting. Future work should investigate the structure and function of the proteins separated from the tissue fluids and we considered it as a limitation of this investigation. The sea bivalve literature is scanty. However the limitation of this work we still can conclude that there are high molecular weight proteins in large concentrations i...

Our aim was to provide information about the production of Egg White Immunoglobulin (EWIg) with s... more Our aim was to provide information about the production of Egg White Immunoglobulin (EWIg) with specificity to Staphylococcal protein-A, a surface antigen of Staphylococcus aureus and to study the inhibition of this bacterium growth in pre- and post-immunized hens. A sandwich Enzyme-Immunosorbent Assay (ELISA) showed a large concentration of anti-SpA antibodies in the eggs from hens immunized with protein A. The titer of these antibodies was at least 5 to 6-folds of that of the eggs from pre-immunized hens 10 days post-immunization. Inhibition of the growth of S. aureus by anti-SpA antibodies purified by SpA-affinity chromatography (PURE-1A) was observed in laying hens vaccinated. Growth of the bacteria in blood agar plates occurred in antibody samples from preimmunized laying hens only. Inhibition of the agglutination of SpA-bearing Staphylococcus aureus cells by purified anti-SpA antibodies was observed in vitro. The authors are not aware of previous studies of the primary immune ...

Journal of Veterinary Science and Technology, 2015

Objective: To purify IgG molecules from several species by SpA-affinity chromatography and to stu... more Objective: To purify IgG molecules from several species by SpA-affinity chromatography and to study the interactions of mammalian IgGs with a peroxidase-labelled SpL, SpA and SpG conjugate (SPLAG-HRP) in an enzyme-linked immunosorbent assay (ELISA). Materials and methods: The periodate method described by Nakane and Kawoi was used to prepare the SPLAG-HRP conjugate. The 10% non-denaturing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of sera and purified immunoglobulins was carried out to characterize molecularly the purified IgGs. The chicken IgY fraction was isolated by the chloroform-polyethylene glycol (PEG) method for its use as a negative control in the ELISA that was used to determine the affinity of different immunoglobulins to a SPLAG-HRP conjugate. Results: The SpA-affinity chromatography and the 10% non-denaturing SDS-PAGE of sera and purified immunoglobulins (IgGs) were useful separation techniques. Most purified IgGs interacted moderately with th...

Journal of analytical and bioanalytical techniques, 2015

2Biochemistry Section, Department of Basic Medical Sciences, The University of the West Indies, M... more 2Biochemistry Section, Department of Basic Medical Sciences, The University of the West Indies, Mona Campus, Jamaica, West Indies *Corresponding author: Angel Justiz-Vaillant, Pathology and Microbiology Unit, Department of Para-Clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies; Tel: +868-773-5914; E-mail: angel.vaillant@sta.uwi.edu

Angel Alberto Justiz Vaillant1*, Wayne Mohammed1, Sehlule Vuma1 and Norma Anderson2 1Department o... more Angel Alberto Justiz Vaillant1*, Wayne Mohammed1, Sehlule Vuma1 and Norma Anderson2 1Department of Para-clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, Trinidad and Tobago, West Indies 2Department of Basic Medical Sciences, The University of the West Indies, Mona campus, Jamaica, West Indies *Corresponding author: Angel Alberto Justiz Vaillant, Department of Para-clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine Campus, Trinidad and Tobago, West Indies, E-mail: avail4883@gmail.com

Journal of Marine Science: Research & Development, 2014

The aim of this preliminary study was to investigate the presence of proteins in the tissue fluid... more The aim of this preliminary study was to investigate the presence of proteins in the tissue fluids of the sea mussel Isognomon alatus. Protein extraction was done by the chloroform-cold ethanol technique. Immunization for production of antibody to be used as reagents in Western blotting, assessment of the protein concentration by the Bradford method, protein characterization by native polyacrylamide gel electrophoresis (PAGE) were also performed as a part of the methodology of this study. The results showed a protein content of 65 mg/ml in tissue fluids and a protein band approximately of 220 kDa in PAGE that was further confirmed by the Western blotting. Future work should investigate the structure and function of the proteins separated from the tissue fluids and we considered it as a limitation of this investigation. The sea bivalve literature is scanty. However the limitation of this work we still can conclude that there are high molecular weight proteins in large concentrations ...

Immunome Research, 2018

Streptococcal protein-G (SpG), type III bacterial Fc receptor, is a small globular protein produc... more Streptococcal protein-G (SpG), type III bacterial Fc receptor, is a small globular protein produced by several Streptococcal species and it is composed of two or three nearly identical domains, each of 55 amino acids. Streptococcal protein G has been shown to have high binding affinity to sera from various mammalian species including rabbit, human, pig, goat, sheep, cow and many other animal species. Of concern are patients with invasive infections by Streptococcus spp, where large amount of secreted SpG could interfere with the outcome of the gel technique by getting false negative tests. It has been shown and reported that the bacterial protein SpA was already found to inhibit the Coomb's test. We hypothesize that SpG as well as many other immunoglobulin-binding bacterial proteins with binding affinity to human IgG could cause false negative results in patients with bacteraemia. With the intention of proving this hypothesis we conducted two sets of experiments, which proved that SpG has the potential of inhibiting the gel test for the detection of sensitized erythrocytes in vitro. We concluded that is important to exercise caution, when evaluating a result of gel technique in patients with septicemia caused by SpG-producer Streptococci. The experiments used in this research were novel modifications of existent techniques and they proved reliable in demonstrating our hypothesis.

BMJ Case Reports, 2018

this case presents a woman in her early 20s who died after the sudden onset of chest pain. Five y... more this case presents a woman in her early 20s who died after the sudden onset of chest pain. Five years earlier, she was investigated for a cardiac murmur during pregnancy and an echocardiogram revealed a 6.0×3.0 cm blood-filled sac compressing the left atrium and anterolateral aspect of the left ventricle with communication to the aortic root. she later had a Ct scan of the chest with contrast, which showed aneurysmal dilatation of the left main coronary artery. she was placed on aspirin but defaulted from clinic 11 months post partum. at autopsy, a left coronary aneurysmal sac measuring 10.0×9.0 cm. was identified with a rupture measuring 7.0 cm in length and the pericardial sac contained 900 mL of blood with clots. the cause of death was cardiac tamponade secondary to rupture of the coronary artery aneurysm.

Journal of surgical case reports, 2018

Splenic artery aneurysms (SAAs) are an extremely rare cause of asymptomatic massive lower gastroi... more Splenic artery aneurysms (SAAs) are an extremely rare cause of asymptomatic massive lower gastrointestinal bleeding with less than a handful of patients surviving such a presentation. A 24-year-old female presented in shock after multiple episodes of massive rectal bleeding. Imaging revealed a heterogeneous mass arising from the tail of the pancreas eroding into the splenic flexure of the colon. Further episodes of bleeding led to an exploratory laparotomy. Intraoperatively, a suspected neoplastic process arising from the tail of the pancreas with contiguous involvement of the splenic flexure of the colon and the greater curvature of the stomach was noted. Distal pancreaticosplenectomy, gastric wedge resection with segmental colectomy and primary anastomosis were performed. Histology revealed a SAA with rupture into the colon. This case report shows that en-bloc resection of a ruptured SAA can be performed with success in the emergency setting.

International journal of surgery case reports, Jan 4, 2017

Phyllodes tumors (PTs) of the breast are extremely rare accounting for less than 1% of all breast... more Phyllodes tumors (PTs) of the breast are extremely rare accounting for less than 1% of all breast tumors globally. Case records at the Trinidad and Tobago Cancer Registry show that only 0.003% of the reported breast cancer cases between 1995 and 2009 were PTs. We report a 45-year-old woman who presented with swelling of the left breast. Ultrasound, mammogram and computed tomography imaging confirmed the presence of a mass in the right upper inner quadrant of the left breast. A biopsy revealed features supportive of a benign phyllodes tumor. A wide local excision was performed with the removal of a 19×11×10cm mass. Histopathological analysis revealed features consistent with malignant phyllodes tumor. A complete mastectomy of the left breast was subsequently performed. Follow up over a 5-year period did not reveal any evidence of local recurrence or residual disease. To the best of our knowledge, this is the first case report of a malignant PT from the Caribbean and Latin America. Ph...

International journal of surgery case reports, Jan 7, 2017

Pelvic exenteration (PE) is an ultra-radical surgical procedure characterized by the en bloc rese... more Pelvic exenteration (PE) is an ultra-radical surgical procedure characterized by the en bloc resection of the pelvic organs. In this case series, we report retrospectively on four patients who underwent PE in Trinidad and Tobago from 2012 to 2016. One male patient had rectal cancer while one each of three women had cervical, colon, or rectal cancer. Early postoperative complications (≤30days) occurred in all patients, while late complications (>30days) occurred in one patient (Grade 1 - Clavien-Dindo classification). Disease recurrence occurred in 50% of patients, and the median overall survival was 8 months (range, 4-15 months). There are many inherent challenges to conducting such major procedures in developing countries, including inadequate blood product supplies, intensive care unit beds, and pre- and post-operative support services. With increased surgical capacity and support infrastructure, hospitals in these regions would be equipped to perform PEs with better outcomes. ...