Identification of Suitable Guar Genotypes for Summer Season of Semi-Arid Region.

Cluster bean (Cyamopsis tetragonoloba (L.) Taub.) is a nitrogen-fixing legume has been used as a green manure, forage and as a seed crop. Guar gum, extracted from the pods of the guar plant, is widely used as an emulsifier, thickener and stabiliser in food and cosmetics. Approximately 23% of the guar seed is the gum (galactomannin). With growing international demand for the guar gum, identification or development of suitable varieties for different agro climatic conditions along with high seed yield and quality gum is the pressing need of the hour. To address these issues five guar varieties were evaluated during summer for their yield potential along with biotic factors. The genotype RGC-1017 performed better for biomass, pod number and seed yield as well as showed resistance to cutworm disease. RGC-986 a long duration variety produced high vegetative biomass with good root and shoot system may serve as a dual purpose variety for fodder and seed.

Relative efficiency of polymerase chain reaction and enzyme-linked immunosorbant assay in determination of viral etiology in congenital cataract in infants.

BACKGROUND: Perinatal viral infections of fetus are among the leading causes of congenital cataract and identifying the viral etiology is important. OBJECTIVES: To detect the presence of Rubella virus (RV), herpes simplex virus (HSV) and cytomegalovirus (CMV) in lens aspirate specimens obtained from patients with congenital cataract and relate the results with serology. SETTING AND DESIGN: Prospective study carried out in tertiary care hospital. MATERIALS AND METHODS: Fifty lens aspirates from 50 infants with congenital cataract were subjected to HSV, RV isolation and polymerase chain reaction (PCR) for detection of HSV and CMV. Reverse transcription polymerase chain reaction (RT-PCR) was applied for RV detection. Peripheral blood specimens were screened for anti-HSV, RV and CMV antibodies by enzyme-linked immunosorbant assay (ELISA). RESULTS: Rubella virus was detected in nine (18%) lens aspirates, by nRT-PCR which includes six positive by culture. HSV-2 DNA was detected in nine other lens aspirates, while CMV was not detected by PCR. Serological results did not correlate with the presence of viruses in the lens aspirates. This is the first report of detection of HSV-2 DNA in cases of congenital cataract. CONCLUSIONS: Cytomegalovirus may not be playing a significant role in causation of congenital cataract. The role of serology in identifying causative viral infection for congenital cataract needs to be re-evaluated.

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

BACKGROUND & OBJECTIVE: 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. METHODS: 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. RESULTS: 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 whereas single genotypes were identified by PCR-based RFLP. INTERPRETATION & CONCLUSION: Multiplex nested PCR provided a rapid, sensitive and cost-effective assay for gB genotyping of HCMV and allowed detection of multiple gB genotypes of HCMV in clinical samples compared to PCR-based RFLP.

Application of polymerase chain reaction to differentiate herpes simplex virus 1 and 2 serotypes in culture negative intraocular aspirates.

PURPOSE: To standardize and apply a polymerase chain reaction (PCR) on the glycoprotein D gene to differentiate Herpes simplex virus (HSV) 1 & 2 serotypes in culture negative intraocular specimens. METHODS: Twenty-one intraocular fluids collected from 19 patients were subjected to cultures for HSV and uniplex PCR (uPCR) for DNA polymerase gene. To differentiate HSV serotypes, as 1 & 2, a seminested PCR (snPCR) targeting the glycoprotein D gene was standardised and applied onto 21 intraocular fluids. The specificity of the snPCR was verified by application onto ATCC strains of HSV 1 and 2, clinical isolates and DNA sequencing of the amplified products. All specimens were also tested for the presence of cytomegalovirus (CMV) and varicella zoster virus (VZV) by nucleic acid amplification methods. RESULTS: Four of the 21 intraocular fluids were positive for HSV by uPCR. snPCR detected HSV in three additional specimens (total of seven specimens), and identified three as HSV 1 and four as HSV 2. DNA sequencing of PCR products showed 100% homology with the standard strains of HSV 1 and 2 respectively. None of the samples were positive in culture. Among the other patients, CMV DNA was detected in two and VZV DNA in five others. CONCLUSIONS: The standardized snPCR can be applied directly onto the culture negative specimens for rapid differentiation of HSV serotypes.

Body proportions in Fanconi anemia heterozygotes.

To study the anthropometric ratios in parents (heterozygotes) of children with Fanconi anemia. The study was carried out in the Department of Hematology, Institute of Child Health & Hospital for Children, Chennai. Parents of children with Fanconi anemia were the subjects of the study. Applying standard instruments and methods, various body measurements were recorded. 31 fathers and 37 mothers were included in the study. A hundred male and female controls of the same ethnic group were also studied for the same parameters. The ratios were calculated and statistically analyzed. It was observed that fathers (male heterozygotes) had shorter forearms, the ratio of upper arm: forearm was significantly increased compared to male controls. In mothers (female heterozygotes) the inter-pupillary distance was increased, the ratio of head circumference to inter-pupillary distance was decreased compared to female controls.