H. Madhavan - Academia.edu (original) (raw)

Papers by H. Madhavan

Research paper thumbnail of Profiling of human leukocyte antigens in Eales disease and tuberculosis

International Ophthalmology, 2013

To analyze the association between Eales disease, histocompatibility leukocyte antigen alleles (H... more To analyze the association between Eales disease, histocompatibility leukocyte antigen alleles (HLA-A/B, HLA-DRB/DQB) and tuberculosis infection, and to explore susceptible genes and protective genes associated with Eales disease and tuberculosis infection in a population of Han nationals from Zunyi City in Guizhou Province, China. The subjects were analyzed by a case-control study consisting of three groups--Eales disease group (47 cases), pulmonary tuberculosis group (36 cases) and normal control group (100 cases). The Eales disease group was divided into four parts. Part one consisted of 12 patients who had suffered from pulmonary tuberculosis. Part two consisted of 27 patients who had not suffered from pulmonary tuberculosis. Parts three and four consisted of 27 patients with a positive purified protein derivative test and 12 patients with a negative test, respectively. DNA samples from 47 patients with Eales disease, 36 patients with pulmonary tuberculosis and 100 healthy people were detected by polymerase chain reaction with sequence-specific primers. The 59 HLA-A/B and HLA-DRB/DQB alleles from Eales disease were compared with those from tuberculosis and normal control, and a correlativity test of common susceptible genes was performed to analyze the potential relationship between Eales disease and pulmonary tuberculosis. The frequency distribution of HLA-A*02 alleles (OR 9.719, OR 95 % CI 4.377-21.580, P = 0.000) and HLA-B*07 (OR 11.605, OR 95 % CI 2.397-56.191, P = 0.001) in the Eales disease group was higher than in the normal control group, but the HLA-A*11 alleles (OR 0.495, OR 95 % CI 0.245-1.000, P = 0.048) were lower than in the normal control group, showing a significant difference. Compared with parts two and four, the frequency distribution of HLA-A*02, HLA-A*11 and HLA-B*07 alleles in parts one and three showed no significant difference (P > 0.05). HLA-A*A02, HLA-A*24, HLA-B*07 and HLA-DRB*16 alleles between the Eales disease, pulmonary tuberculosis and normal control group showed statistical significance (P < 0.05). HLA-A*24 alleles in the pulmonary tuberculosis group were lower than the Eales disease group (χ(2) 7.289, P = 0.007), but HLA-A*02 alleles showed no significant difference (P > 0.05) between the two groups. The results show that HLA-A*02 and HLA-B*07 may be genetic predisposing genes, but HLA-A*11 alleles may be protective genes of Eales disease, the HLA-A*02 allele may be a common susceptible gene of Eales disease and pulmonary tuberculosis. HLA-A*11 and HLA-A24 alleles are protective genes of Eales disease and pulmonary tuberculosis,…

Research paper thumbnail of Fatal myocarditis in a young female caused by coxsackie virus group B type two

The Journal of the Association of Physicians of India, 1975

Research paper thumbnail of Role of adenoviruses in infections of the nervous system

The Journal of the Association of Physicians of India, 1977

Research paper thumbnail of The frequency of non-A, non-B hepatitis in acute and chronic liver disease

The Medical journal of Malaysia, 1985

Research paper thumbnail of Insights on Drug Targeting of Toxoplasma Gondii Host Invasion Proteins:A Review

Asian Journal of Pharmaceutical and Clinical Research

Toxoplasma gondii is an obligate intracellular parasite that infects homoeothermic animals. It is... more Toxoplasma gondii is an obligate intracellular parasite that infects homoeothermic animals. It is also the major cause of retinochoroiditis in humans. Drugs targeting T. gondii proteins involved in the establishment of host-pathogen interactions is well documented to be an efficient way to combat the infections. Basically, parasitic invasion of T. gondii occurs by the sequential secretion of apical membrane antigen 1 and rhoptry neck proteins on the parasite and host cell surfaces, respectively. These proteins operate synergistically and form the moving junction (MJ) complex, thereby, enabling attachment and penetration of the parasite into the host cell. Better understanding of molecular interactions of these proteins is essential to develop highly efficient therapeutic modalities. Hence, by this review it is intended to update the current status of rhoptry and other MJ complex proteins as ideal candidates for targeting T. gondii.

Research paper thumbnail of Serological evidence for active Epstein-Barr virus infection in multifocal choroiditis

Indian journal of pathology & microbiology, 1997

Six patients, consisting of 4 males and 2 females with mean average age fo 29.20 years, with vari... more Six patients, consisting of 4 males and 2 females with mean average age fo 29.20 years, with variable picture of multifocal choroiditis were serologically investigated for their association with Epstein-Barr Virus (EBV) infection. IgG and IgM antibodies to EBV-Virus Capsid Antigen (VCA) were assayed by immunoperoxidase method on EBV infected lymphoblast cells (P3HR-1 Burkitt's lymphoma cell line). In these patients definite serological evidence of EBV infection with high titres of IgG and IgM antibodies to EBV-VCA was demonstrated suggestive of active continuing or persisting EBV infection.

Research paper thumbnail of Ocular chlamydial infections. Clinicomicrobiological correlation

Cornea, 1996

We report the results of conjunctival scrapings done in 234 eyes of 127 patients presenting with ... more We report the results of conjunctival scrapings done in 234 eyes of 127 patients presenting with acute, chronic, or recurrent conjunctivitis. Although some patients had the classic features of superior pannus, Herbert's pits, conjunctival follicles, and tarsal distortions, others presented in a more subtle fashion mimicking allergic, viral, and bacterial diseases of the eyes. These scrapings were subjected to rapid diagnostic techniques and culture studies for the identification of chlamydial infections. The correlation between the clinical and laboratory diagnosis was studied. Of the 127 patients, 44 were culture positive for Chlamydia. Of these, only 19 had been clinically suspected to have chlamydial ocular disease, whereas the others were diagnosed to have bacterial, viral, allergic, or other diseases. This higher rate of Chlamydia detection is probably a reflection of endemicity of this infection in India. This article highlights the possible underdiagnosis of chlamydial oc...

Research paper thumbnail of Skin and mucous membrane as reservoirs of Bacterium anitratum and Mima polymorpha in patients

Journal of the Indian Medical Association, Jan 16, 1972

Research paper thumbnail of Enteroviruses from cases of encephalitis in Pondicherry

The Indian journal of medical research, 1969

Research paper thumbnail of Application of PCR based-RFLP for species identification of ocular isolates of methicillin resistant staphylococci (MRS)

The Indian journal of medical research, 2009

Early detection of methicillin resistant staphylococci (MRS) from clinical specimens enables inst... more Early detection of methicillin resistant staphylococci (MRS) from clinical specimens enables institution of appropriate antimicrobial therapy. Limited information is available on speciation of MRS. This study was undertaken to compare results of conventional and molecular methods in detection of methicillin resistance (MR) and application of PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing for speciation of ocular isolates of MRS. A total of 110 consecutive ocular staphylococcal isolates were screened for MR. MRS was speciated by PCR-RFLP of gap gene and results were confirmed by DNA sequencing. All isolates were processed within 48 h of isolation. A single colony of bacterium, stocked as stab cultures in Hyer's and Johnson agar, was stored at 4 degrees C and sub-cultured at every 15 days interval. Seventy (63.6%) of 110 isolates were identified as MRS and 40 (36.4%) were MSS by conventional and molecular method (100% correlation). Of the 70 MRS, 18 (25.7%)...

Research paper thumbnail of DNA sequencing by Microseq kit targeting 16S rRNA gene for species level identification of mycobacteria

The Indian journal of medical research, 2009

Identification of mycobacteria to the species level is of therapeutic significance. Conventional ... more Identification of mycobacteria to the species level is of therapeutic significance. Conventional methods are laborious and time consuming so we did 16S rRNA sequencing using a commercial MicroSeq sequencing kit, which includes DNA sequencing with software package for identification and phylogenetic analysis of clinical mycobacterial isolates. A total of 47 mycobacteria were tested by both conventional and genotypic method using commercially available MicroSeq 500 amplification kit assay. The identification was determined by comparing the 500 bp amplified product of 16S rDNA sequence to the MicroSeq database. The phenotypic identification was concordant with genotypic identification in 33 (70.2%) isolates of 14 Mycobacterium tuberculosis, 11 M. fortuitum, 7 M. abscessus and 1 M. duvalii. For the discrepant isolates, identification was possible only by DNA sequencing in 14 (29.7%) isolates. The 14 discrepant isolates were 5 M. farcinogenes, 3 M. genavense, 2 M. species. nov and 1 each...

Research paper thumbnail of Comparative efficacy of PCR-based restriction fragment length polymorphism (RFLP) & multiplex PCR for glycoprotein B (gB) genotyping of human cytomegalovirus

The Indian journal of medical research, 2007

Glycoprotein B (gB), involved in cell-to-cell transmission of human cytomegalovirus (HCMV), is a ... more Glycoprotein B (gB), involved in cell-to-cell transmission of human cytomegalovirus (HCMV), is a critical factor in tissue tropism and viral pathogenesis. The aim of the present study was to compare the efficiency of PCR-based RFLP and multiplex nested PCR for gB gene of HCMV to determine their genotype in clinical specimens from patients with HCMV. The PCR based RFLP and the multiplex nested PCR were applied on standard strain of HCMV AD169, 4 clinical HCMV isolates and 70 clinical specimens positive for HCMV by pp65 antigenaemia assay or nested PCR for mtr II region or both. Three of the four clinical isolates were genotyped as gB1 and the other as gB3 by both the methods. HCMV genome in all the 70 clinical specimens were genotyped by multiplex nested PCR whereas only 65 were genotyped by PCR-based RFLP. Forty one of 65 clinical specimens, gave concordant results by both methods. In the remaining 24, mixed infection with multiple genotypes was identified by multiplex nested PCR wh...

Research paper thumbnail of Evaluation of three polymerase chain reaction tests targeting morphological transforming region II, UL-83 gene and glycoprotein O gene for the detection of human cytomegalovirus genome in clinical specimens of immunocompromised patients in Chennai, India

Virology journal, 2006

Human Cytomegalovirus (HCMV) continues to be an important cause of morbidity and occasional morta... more Human Cytomegalovirus (HCMV) continues to be an important cause of morbidity and occasional mortality in immunocompromised patients. Polymerase chain reaction (PCR) is the most sensitive and commonly used method for the assessment of HCMV infection in the immunocompromised patients at risk from severe associated clinical manifestations. However, there is little consistency in the qualitative PCR used for different regions of HCMV genome. Therefore, the performance of three Qualitative PCR tests to detect HCMV genome in clinical specimens from immunocompromised patients was evaluated. With pp65 antigenemia assay as the "gold standard", nested PCR for morphological transforming region II (mtr II) and glycoprotein O (gO) gene and uniplex PCR for UL 83 gene were applied on 92 consecutive clinical specimens obtained from 74 immunocompromised patients with clinically suspected HCMV disease. Virus isolation was attempted on 12 clinical specimens from six pp65 antigenemia positive...

Research paper thumbnail of A hospital based study on the prevalence of conjunctivitis due to Chlamydia trachomatis

The Indian journal of medical research, 2003

Very few studies have been done in India to determine the prevalence of Chlamydia trachomatis cau... more Very few studies have been done in India to determine the prevalence of Chlamydia trachomatis causing conjunctivitis using polymerase chain reaction (PCR) methods. Hence the prevalence of primary conjunctivitis due to C. trachomatis among individuals attending ophthalmic hospitals in Chennai was determined and compared with our earlier results. A total of 328 conjunctival swabs from 255 (both eyes 73 and one eye 182) patients were investigated by fluorescent antibody test (FAT) on direct smears, culture and PCRs for cryptic plasmid and major outer membrane protein (MOMPI) gene of C. trachomatis. An infant with ophthalmia neonatorum was also included. Among these 328 specimens processed, 16 (4.9%) from 12 (4.7%) patients were positive by cryptic plasmid PCR. Among these, 3 from 2 patients were positive by FAT (direct smear), culture and PCR for MOMP 1 gene. Both eyes of the infant with ophthalmia neonatorum were positive by all the methods. The sensitivity of FAT and culture (18.8%) ...

Research paper thumbnail of Polymerase chain reaction using IS6110 primer to detect Mycobacterium tuberculosis in clinical samples

Indian journal of pathology & microbiology, 2001

Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical ... more Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical specimens has been extensively used as laboratory tool for the diagnosis for tuberculosis. Despite it's dramatic scientific value in practice, it is not as sensitive as expected for the detection of M. tuberculosis. The results of the study suggest that PCR using 123 bp fragment of DNA belonging to IS6110 is specific (95.6%) but only has a sensitivity of 30% to detect M. tuberculosis in clinical specimens.

Research paper thumbnail of Papilloedema with peripapillary retinal haemorrhages in an acquired immunodeficiency syndrome (AIDS) patient with cryptococcal meningitis

Indian journal of ophthalmology, 2000

A case of cryptococcal meningitis in an AIDS patient who presented with optic disc edema, bilater... more A case of cryptococcal meningitis in an AIDS patient who presented with optic disc edema, bilateral retinal and peripapillary haemorrhages is reported.

Research paper thumbnail of Nocardia Asteroides keratitis: report of seven patients and literature review

Indian journal of ophthalmology, 2000

To describe clinical features and treatment outcomes in patients with advanced Nocardia asteroide... more To describe clinical features and treatment outcomes in patients with advanced Nocardia asteroides keratitis. Retrospective review of case records of 7 patients with culture-proven Nocardia keratitis. Corneal infection occurred after corneal trauma in two patients, cataract surgery in three patients, penetrating keratoplasty in one patient and was associated with a silicone buckle element infection in one patient. Mean duration of infection at presentation was 33.4 days (7-75 days), and five patients had received prior treatment with corticosteroids. Six of seven patients had deep corneal suppuration at the time of presentation, clinically suggestive of mycotic keratitis. In two patients who had received prolonged corticosteroid therapy (> or = 45 days), the eyes could not be salvaged. Complete resolution of infection was achieved in all 4 eyes treated with topical fortified cefazolin eye drops (50 mg/ml).

Research paper thumbnail of Microbiological assay of ampicillin in serum and aqueous humor of patients given ampicillin-sulbactam injection

Indian journal of ophthalmology, 1998

The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin i... more The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin in aqueous humor and serum of patients administered ampicillin-sulbactam combination intramuscularly prior to cataract surgery. 43 patients received a combination of both antibiotics intramuscularly at varying periods (60-140 minutes) prior to surgery. Aqueous humor and venous blood were collected at the beginning of the surgery. For microbiological assay, spores of Bacillus subtilis were incorporated in the agar. The test sample and the standard solutions (calibrators) of ampicillin and ampicillin-sulbactam combination were placed in 3 mm wells in the agar. The diameter zones of growth inhibitory activities of ampicillin of the calibrators and the test samples measured in mm were extrapolated to the standard curve and were recorded as ampicillin activity in micrograms/ml. The results of the assay were placed in 5 groups according to the time intervals between injection and collection of ...

Research paper thumbnail of Effects of viscoelastic ophthalmic solutions on cell cultures

Indian journal of ophthalmology, 1998

The development of mild but significant inflammation probably attributable to viscoelastic ophtha... more The development of mild but significant inflammation probably attributable to viscoelastic ophthalmic solutions in cataract surgery was recently brought to the notice of the authors, and hence a study of the effects of these solutions available in India, on cell cultures was undertaken. We studied the effects of 6 viscoelastic ophthalmic solutions (2 sodium hyaluronate designated as A and B, and 4 hydroxypropylmethylcellulose designated as C, D, E and F) on HeLa, Vero and BHK-21 cell lines in tissue culture microtitre plates using undiluted, 1:10 and 1:100 dilutions of the solutions, and in cover slip cultures using undiluted solutions. Phase contrast microscopic examination of the solutions was also done to determine the presence of floating particles. The products D and F produced cytotoxic changes in HeLa cell line and these products also showed the presence of floating particles under phase contrast microscopy. Other products did not have any adverse effects on the cell lines no...

Research paper thumbnail of Blepharitis and lid ulcer as initial ocular manifestation in acquired immunodeficiency syndrome patients

Indian journal of ophthalmology, 1997

... Arch Dermatol 1994;130:521-22. Back to cited text no. 5. 6. Tomar VPS, Sharma OP, and Joski K... more ... Arch Dermatol 1994;130:521-22. Back to cited text no. 5. 6. Tomar VPS, Sharma OP, and Joski K. Bacterial and fungal flora of normal conjunctiva. Ann Ophthalmol 1971;3:669. Back to cited text no. 6. Figures. [Figure - 1], [Figure - 2]. Top. ...

Research paper thumbnail of Profiling of human leukocyte antigens in Eales disease and tuberculosis

International Ophthalmology, 2013

To analyze the association between Eales disease, histocompatibility leukocyte antigen alleles (H... more To analyze the association between Eales disease, histocompatibility leukocyte antigen alleles (HLA-A/B, HLA-DRB/DQB) and tuberculosis infection, and to explore susceptible genes and protective genes associated with Eales disease and tuberculosis infection in a population of Han nationals from Zunyi City in Guizhou Province, China. The subjects were analyzed by a case-control study consisting of three groups--Eales disease group (47 cases), pulmonary tuberculosis group (36 cases) and normal control group (100 cases). The Eales disease group was divided into four parts. Part one consisted of 12 patients who had suffered from pulmonary tuberculosis. Part two consisted of 27 patients who had not suffered from pulmonary tuberculosis. Parts three and four consisted of 27 patients with a positive purified protein derivative test and 12 patients with a negative test, respectively. DNA samples from 47 patients with Eales disease, 36 patients with pulmonary tuberculosis and 100 healthy people were detected by polymerase chain reaction with sequence-specific primers. The 59 HLA-A/B and HLA-DRB/DQB alleles from Eales disease were compared with those from tuberculosis and normal control, and a correlativity test of common susceptible genes was performed to analyze the potential relationship between Eales disease and pulmonary tuberculosis. The frequency distribution of HLA-A*02 alleles (OR 9.719, OR 95 % CI 4.377-21.580, P = 0.000) and HLA-B*07 (OR 11.605, OR 95 % CI 2.397-56.191, P = 0.001) in the Eales disease group was higher than in the normal control group, but the HLA-A*11 alleles (OR 0.495, OR 95 % CI 0.245-1.000, P = 0.048) were lower than in the normal control group, showing a significant difference. Compared with parts two and four, the frequency distribution of HLA-A*02, HLA-A*11 and HLA-B*07 alleles in parts one and three showed no significant difference (P > 0.05). HLA-A*A02, HLA-A*24, HLA-B*07 and HLA-DRB*16 alleles between the Eales disease, pulmonary tuberculosis and normal control group showed statistical significance (P < 0.05). HLA-A*24 alleles in the pulmonary tuberculosis group were lower than the Eales disease group (χ(2) 7.289, P = 0.007), but HLA-A*02 alleles showed no significant difference (P > 0.05) between the two groups. The results show that HLA-A*02 and HLA-B*07 may be genetic predisposing genes, but HLA-A*11 alleles may be protective genes of Eales disease, the HLA-A*02 allele may be a common susceptible gene of Eales disease and pulmonary tuberculosis. HLA-A*11 and HLA-A24 alleles are protective genes of Eales disease and pulmonary tuberculosis,…

Research paper thumbnail of Fatal myocarditis in a young female caused by coxsackie virus group B type two

The Journal of the Association of Physicians of India, 1975

Research paper thumbnail of Role of adenoviruses in infections of the nervous system

The Journal of the Association of Physicians of India, 1977

Research paper thumbnail of The frequency of non-A, non-B hepatitis in acute and chronic liver disease

The Medical journal of Malaysia, 1985

Research paper thumbnail of Insights on Drug Targeting of Toxoplasma Gondii Host Invasion Proteins:A Review

Asian Journal of Pharmaceutical and Clinical Research

Toxoplasma gondii is an obligate intracellular parasite that infects homoeothermic animals. It is... more Toxoplasma gondii is an obligate intracellular parasite that infects homoeothermic animals. It is also the major cause of retinochoroiditis in humans. Drugs targeting T. gondii proteins involved in the establishment of host-pathogen interactions is well documented to be an efficient way to combat the infections. Basically, parasitic invasion of T. gondii occurs by the sequential secretion of apical membrane antigen 1 and rhoptry neck proteins on the parasite and host cell surfaces, respectively. These proteins operate synergistically and form the moving junction (MJ) complex, thereby, enabling attachment and penetration of the parasite into the host cell. Better understanding of molecular interactions of these proteins is essential to develop highly efficient therapeutic modalities. Hence, by this review it is intended to update the current status of rhoptry and other MJ complex proteins as ideal candidates for targeting T. gondii.

Research paper thumbnail of Serological evidence for active Epstein-Barr virus infection in multifocal choroiditis

Indian journal of pathology & microbiology, 1997

Six patients, consisting of 4 males and 2 females with mean average age fo 29.20 years, with vari... more Six patients, consisting of 4 males and 2 females with mean average age fo 29.20 years, with variable picture of multifocal choroiditis were serologically investigated for their association with Epstein-Barr Virus (EBV) infection. IgG and IgM antibodies to EBV-Virus Capsid Antigen (VCA) were assayed by immunoperoxidase method on EBV infected lymphoblast cells (P3HR-1 Burkitt's lymphoma cell line). In these patients definite serological evidence of EBV infection with high titres of IgG and IgM antibodies to EBV-VCA was demonstrated suggestive of active continuing or persisting EBV infection.

Research paper thumbnail of Ocular chlamydial infections. Clinicomicrobiological correlation

Cornea, 1996

We report the results of conjunctival scrapings done in 234 eyes of 127 patients presenting with ... more We report the results of conjunctival scrapings done in 234 eyes of 127 patients presenting with acute, chronic, or recurrent conjunctivitis. Although some patients had the classic features of superior pannus, Herbert's pits, conjunctival follicles, and tarsal distortions, others presented in a more subtle fashion mimicking allergic, viral, and bacterial diseases of the eyes. These scrapings were subjected to rapid diagnostic techniques and culture studies for the identification of chlamydial infections. The correlation between the clinical and laboratory diagnosis was studied. Of the 127 patients, 44 were culture positive for Chlamydia. Of these, only 19 had been clinically suspected to have chlamydial ocular disease, whereas the others were diagnosed to have bacterial, viral, allergic, or other diseases. This higher rate of Chlamydia detection is probably a reflection of endemicity of this infection in India. This article highlights the possible underdiagnosis of chlamydial oc...

Research paper thumbnail of Skin and mucous membrane as reservoirs of Bacterium anitratum and Mima polymorpha in patients

Journal of the Indian Medical Association, Jan 16, 1972

Research paper thumbnail of Enteroviruses from cases of encephalitis in Pondicherry

The Indian journal of medical research, 1969

Research paper thumbnail of Application of PCR based-RFLP for species identification of ocular isolates of methicillin resistant staphylococci (MRS)

The Indian journal of medical research, 2009

Early detection of methicillin resistant staphylococci (MRS) from clinical specimens enables inst... more Early detection of methicillin resistant staphylococci (MRS) from clinical specimens enables institution of appropriate antimicrobial therapy. Limited information is available on speciation of MRS. This study was undertaken to compare results of conventional and molecular methods in detection of methicillin resistance (MR) and application of PCR-restriction fragment length polymorphism (RFLP) and DNA sequencing for speciation of ocular isolates of MRS. A total of 110 consecutive ocular staphylococcal isolates were screened for MR. MRS was speciated by PCR-RFLP of gap gene and results were confirmed by DNA sequencing. All isolates were processed within 48 h of isolation. A single colony of bacterium, stocked as stab cultures in Hyer's and Johnson agar, was stored at 4 degrees C and sub-cultured at every 15 days interval. Seventy (63.6%) of 110 isolates were identified as MRS and 40 (36.4%) were MSS by conventional and molecular method (100% correlation). Of the 70 MRS, 18 (25.7%)...

Research paper thumbnail of DNA sequencing by Microseq kit targeting 16S rRNA gene for species level identification of mycobacteria

The Indian journal of medical research, 2009

Identification of mycobacteria to the species level is of therapeutic significance. Conventional ... more Identification of mycobacteria to the species level is of therapeutic significance. Conventional methods are laborious and time consuming so we did 16S rRNA sequencing using a commercial MicroSeq sequencing kit, which includes DNA sequencing with software package for identification and phylogenetic analysis of clinical mycobacterial isolates. A total of 47 mycobacteria were tested by both conventional and genotypic method using commercially available MicroSeq 500 amplification kit assay. The identification was determined by comparing the 500 bp amplified product of 16S rDNA sequence to the MicroSeq database. The phenotypic identification was concordant with genotypic identification in 33 (70.2%) isolates of 14 Mycobacterium tuberculosis, 11 M. fortuitum, 7 M. abscessus and 1 M. duvalii. For the discrepant isolates, identification was possible only by DNA sequencing in 14 (29.7%) isolates. The 14 discrepant isolates were 5 M. farcinogenes, 3 M. genavense, 2 M. species. nov and 1 each...

Research paper thumbnail of Comparative efficacy of PCR-based restriction fragment length polymorphism (RFLP) & multiplex PCR for glycoprotein B (gB) genotyping of human cytomegalovirus

The Indian journal of medical research, 2007

Glycoprotein B (gB), involved in cell-to-cell transmission of human cytomegalovirus (HCMV), is a ... more Glycoprotein B (gB), involved in cell-to-cell transmission of human cytomegalovirus (HCMV), is a critical factor in tissue tropism and viral pathogenesis. The aim of the present study was to compare the efficiency of PCR-based RFLP and multiplex nested PCR for gB gene of HCMV to determine their genotype in clinical specimens from patients with HCMV. The PCR based RFLP and the multiplex nested PCR were applied on standard strain of HCMV AD169, 4 clinical HCMV isolates and 70 clinical specimens positive for HCMV by pp65 antigenaemia assay or nested PCR for mtr II region or both. Three of the four clinical isolates were genotyped as gB1 and the other as gB3 by both the methods. HCMV genome in all the 70 clinical specimens were genotyped by multiplex nested PCR whereas only 65 were genotyped by PCR-based RFLP. Forty one of 65 clinical specimens, gave concordant results by both methods. In the remaining 24, mixed infection with multiple genotypes was identified by multiplex nested PCR wh...

Research paper thumbnail of Evaluation of three polymerase chain reaction tests targeting morphological transforming region II, UL-83 gene and glycoprotein O gene for the detection of human cytomegalovirus genome in clinical specimens of immunocompromised patients in Chennai, India

Virology journal, 2006

Human Cytomegalovirus (HCMV) continues to be an important cause of morbidity and occasional morta... more Human Cytomegalovirus (HCMV) continues to be an important cause of morbidity and occasional mortality in immunocompromised patients. Polymerase chain reaction (PCR) is the most sensitive and commonly used method for the assessment of HCMV infection in the immunocompromised patients at risk from severe associated clinical manifestations. However, there is little consistency in the qualitative PCR used for different regions of HCMV genome. Therefore, the performance of three Qualitative PCR tests to detect HCMV genome in clinical specimens from immunocompromised patients was evaluated. With pp65 antigenemia assay as the "gold standard", nested PCR for morphological transforming region II (mtr II) and glycoprotein O (gO) gene and uniplex PCR for UL 83 gene were applied on 92 consecutive clinical specimens obtained from 74 immunocompromised patients with clinically suspected HCMV disease. Virus isolation was attempted on 12 clinical specimens from six pp65 antigenemia positive...

Research paper thumbnail of A hospital based study on the prevalence of conjunctivitis due to Chlamydia trachomatis

The Indian journal of medical research, 2003

Very few studies have been done in India to determine the prevalence of Chlamydia trachomatis cau... more Very few studies have been done in India to determine the prevalence of Chlamydia trachomatis causing conjunctivitis using polymerase chain reaction (PCR) methods. Hence the prevalence of primary conjunctivitis due to C. trachomatis among individuals attending ophthalmic hospitals in Chennai was determined and compared with our earlier results. A total of 328 conjunctival swabs from 255 (both eyes 73 and one eye 182) patients were investigated by fluorescent antibody test (FAT) on direct smears, culture and PCRs for cryptic plasmid and major outer membrane protein (MOMPI) gene of C. trachomatis. An infant with ophthalmia neonatorum was also included. Among these 328 specimens processed, 16 (4.9%) from 12 (4.7%) patients were positive by cryptic plasmid PCR. Among these, 3 from 2 patients were positive by FAT (direct smear), culture and PCR for MOMP 1 gene. Both eyes of the infant with ophthalmia neonatorum were positive by all the methods. The sensitivity of FAT and culture (18.8%) ...

Research paper thumbnail of Polymerase chain reaction using IS6110 primer to detect Mycobacterium tuberculosis in clinical samples

Indian journal of pathology & microbiology, 2001

Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical ... more Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical specimens has been extensively used as laboratory tool for the diagnosis for tuberculosis. Despite it's dramatic scientific value in practice, it is not as sensitive as expected for the detection of M. tuberculosis. The results of the study suggest that PCR using 123 bp fragment of DNA belonging to IS6110 is specific (95.6%) but only has a sensitivity of 30% to detect M. tuberculosis in clinical specimens.

Research paper thumbnail of Papilloedema with peripapillary retinal haemorrhages in an acquired immunodeficiency syndrome (AIDS) patient with cryptococcal meningitis

Indian journal of ophthalmology, 2000

A case of cryptococcal meningitis in an AIDS patient who presented with optic disc edema, bilater... more A case of cryptococcal meningitis in an AIDS patient who presented with optic disc edema, bilateral retinal and peripapillary haemorrhages is reported.

Research paper thumbnail of Nocardia Asteroides keratitis: report of seven patients and literature review

Indian journal of ophthalmology, 2000

To describe clinical features and treatment outcomes in patients with advanced Nocardia asteroide... more To describe clinical features and treatment outcomes in patients with advanced Nocardia asteroides keratitis. Retrospective review of case records of 7 patients with culture-proven Nocardia keratitis. Corneal infection occurred after corneal trauma in two patients, cataract surgery in three patients, penetrating keratoplasty in one patient and was associated with a silicone buckle element infection in one patient. Mean duration of infection at presentation was 33.4 days (7-75 days), and five patients had received prior treatment with corticosteroids. Six of seven patients had deep corneal suppuration at the time of presentation, clinically suggestive of mycotic keratitis. In two patients who had received prolonged corticosteroid therapy (> or = 45 days), the eyes could not be salvaged. Complete resolution of infection was achieved in all 4 eyes treated with topical fortified cefazolin eye drops (50 mg/ml).

Research paper thumbnail of Microbiological assay of ampicillin in serum and aqueous humor of patients given ampicillin-sulbactam injection

Indian journal of ophthalmology, 1998

The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin i... more The aim of this study was to determine the bacterial growth inhibitory activities of ampicillin in aqueous humor and serum of patients administered ampicillin-sulbactam combination intramuscularly prior to cataract surgery. 43 patients received a combination of both antibiotics intramuscularly at varying periods (60-140 minutes) prior to surgery. Aqueous humor and venous blood were collected at the beginning of the surgery. For microbiological assay, spores of Bacillus subtilis were incorporated in the agar. The test sample and the standard solutions (calibrators) of ampicillin and ampicillin-sulbactam combination were placed in 3 mm wells in the agar. The diameter zones of growth inhibitory activities of ampicillin of the calibrators and the test samples measured in mm were extrapolated to the standard curve and were recorded as ampicillin activity in micrograms/ml. The results of the assay were placed in 5 groups according to the time intervals between injection and collection of ...

Research paper thumbnail of Effects of viscoelastic ophthalmic solutions on cell cultures

Indian journal of ophthalmology, 1998

The development of mild but significant inflammation probably attributable to viscoelastic ophtha... more The development of mild but significant inflammation probably attributable to viscoelastic ophthalmic solutions in cataract surgery was recently brought to the notice of the authors, and hence a study of the effects of these solutions available in India, on cell cultures was undertaken. We studied the effects of 6 viscoelastic ophthalmic solutions (2 sodium hyaluronate designated as A and B, and 4 hydroxypropylmethylcellulose designated as C, D, E and F) on HeLa, Vero and BHK-21 cell lines in tissue culture microtitre plates using undiluted, 1:10 and 1:100 dilutions of the solutions, and in cover slip cultures using undiluted solutions. Phase contrast microscopic examination of the solutions was also done to determine the presence of floating particles. The products D and F produced cytotoxic changes in HeLa cell line and these products also showed the presence of floating particles under phase contrast microscopy. Other products did not have any adverse effects on the cell lines no...

Research paper thumbnail of Blepharitis and lid ulcer as initial ocular manifestation in acquired immunodeficiency syndrome patients

Indian journal of ophthalmology, 1997

... Arch Dermatol 1994;130:521-22. Back to cited text no. 5. 6. Tomar VPS, Sharma OP, and Joski K... more ... Arch Dermatol 1994;130:521-22. Back to cited text no. 5. 6. Tomar VPS, Sharma OP, and Joski K. Bacterial and fungal flora of normal conjunctiva. Ann Ophthalmol 1971;3:669. Back to cited text no. 6. Figures. [Figure - 1], [Figure - 2]. Top. ...