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Biomedical subjects

L Satyanarayana

Publications and source records attributed to L Satyanarayana.

At least 19 recordsLinked to original sources
PubMed2005

X-ray crystallographic studies on C-phycocyanins from cyanobacteria from different habitats: marine and freshwater.

C-phycocyanins from three cyanobacterial cultures of freshwater and marine habitat, Spirulina, Phormidium and Lyngbya spp., were purified to homogeneity and crystallized using the hanging-drop vapour-diffusion method. Blue-coloured crystals in different crystal forms, monoclinic and hexagonal, were obtained for the three species. The crystals took 1-12 weeks to grow to full size using polyethylene glycols of different molecular weights as precipitants. The amino-acid sequences of these proteins show high similarity to other known C-phycocyanins from related organisms; however, the C-phycocyanins reported here showed different biochemical and biophysical properties, i.e. molecular weight, stability etc. The X-ray diffraction data were collected at resolutions of 3.0 A for the monoclinic and 3.2 and 3.6 A for the hexagonal forms. The unit-cell parameters corresponding to the monoclinic space group P2(1) are a = 107.33, b = 115.64, c = 183.26 A, beta = 90.03 degrees for Spirulina sp. C-phycocyanin and are similar for crystals of Phormidium and Lyngbya spp. C-phycocyanins. Crystals belonging to the hexagonal space group P6(3), with unit-cell parameters a = b = 154.97, c = 40.35 A and a = b = 151.96, c = 39.06 A, were also obtained for the C-phycocyanins from Spirulina and Lyngbya spp., respectively. The estimated solvent content is around 50% for the monoclinic crystals of all three species assuming the presence of two hexamers per asymmetric unit. The solvent content is 66.5 and 64.1% for the hexagonal crystals of C-phycocyanin from Spirulina and Lyngbya spp. assuming the presence of one alphabeta monomer per asymmetric unit.

Crystallography, X-Ray↗
PubMed2005

Catch-up growth in children with late-diagnosed coeliac disease.

Anthropometric parameters and catch-up growth were prospectively evaluated in fifty late-diagnosed children with coeliac disease aged 2.25-10 years after 1-4 years of adhering to a strict gluten-free diet (GFD). The anthropometric parameters were expressed as Z scores relative to National Centre for Health Statistics standards using Epi Info 2000 (weight-for-height Z score (WHZ) and height-for-age Z score (HAZ)). Catch-up growth was evaluated by repeated measures. ANOVA, overall significance by an F test and pair-wise comparisons for estimated marginal means using the least significant difference. At the time of enrolment, no significant difference was observed in WHZ and HAZ between children diagnosed before (group 1) or after (group 2) 4 years of age. On follow-up, HAZ was significantly higher in group 1 after the first and third years of the GFD (P=0.04 and 0.02, respectively), with a non-significant increase after completing 4 years of the GFD (P=0.22). Feeding the GFD resulted in an overall significant (F=3.99, P=0.011) increase in HAZ up to 4 years of follow-up. However, the catch-up in height was incomplete, with stunting in sixteen (55.4%) of twenty-nine children after 3 years and in seven (46.6%) of fifteen children after 4 years on the GFD. Pair-wise comparisons demonstrated a linear catch-up growth during the initial follow-up on GFD. Treatment with the GFD did not result in an overall significant increase in WHZ up to 4 years of follow-up (F=1.01, P=0.42). Our results suggest that, in children with late-diagnosed coeliac disease, treatment with a GFD leads to a normalisation of body mass and a significant but incomplete recovery in HAZ during 4 years of follow-up.

Analysis of Variance↗
PubMed2001

Early detection of cervical cancer through acetic acid application--an aided visual inspection.

OBJECTIVE: To assess the sensitivity and specificity of visual inspection of cervix for detection of precancerous and early cancerous lesions of cervix. METHODS: In a Maternal and Child Health Care setting of New Delhi women underwent a detailed pelvic examination, visual inspection of cervix after 5% acetic acid application, cytology (pap smear), detailed colposcopic examination and colposcopic directed biopsy when indicated. RESULTS: Findings of aided visual inspection using 5% acetic acid and of cytology were evaluated among symptomatic 402 women against colposcopic findings and/or histologic reports. Seventy-three mild dysplasias, 50 moderate dysplasias, 45 severe dysplasias/Carcinoma in-situ and 40 early invasive cancerous cases were diagnosed histologically. The sensitivity of cytology (75.3%) was higher compared to that of acetic acid application (52.0%) for mild dysplasias. On the other hand, the sensitivity for detecting moderate dysplasias was 78% for cytology and 81.6% for acetic acid; for severe dysplasias/carcinoma in-situ it was 73.3% for cytology and 86.7% for acetic acid. For invasive cancers sensitivity for acetic acid application and cytology (95% for both modalities) was comparable. The specificity of cytology (99%) was higher compared to that of acetic acid application (94.3%). The false positive rate for cytology was 1.0% as against 5.7% for acetic acid application. The results of acetic acid application also showed a remarkable improvement in the sensitivity of unaided visual inspection for early cancerous lesion which was about 60% for early cancerous lesion and only 12% for mild dysplastic and 20% for moderate and severe dysplastic lesions in our earlier experience. It also reduced the false positive rates from 12% by unaided visual inspection to 5.7% by acetic acid application. Furthermore, cost of detection of one true lesion through acetic acid application (Rs.1689.00) was much lower as compared to the cost involved in cytology detected true lesions (Rs.2227.00). Visual inspection without acetic acid incurred Rs.6608.60 for detection of true lesion. CONCLUSION: Screening for cervical precancerous and cancerous lesions using visual inspection aided by acetic acid may be a suitable low-cost and a feasible alternative modality for control of cervical cancer in a resource poor setting.

Acetic Acid↗
PubMed2000

Erythromycin in pityriasis rosea: A double-blind, placebo-controlled clinical trial.

BACKGROUND: The study stemmed from an incidental observation of improvement in 2 patients with pityriasis rosea while receiving erythromycin. OBJECTIVE: The purpose of the study was to evaluate the efficacy of erythromycin in patients with pityriasis rosea. METHODS: A double-blind, placebo-controlled clinical study was performed in an outpatient setting in a major hospital. Ninety patients over a period of 2 years were alternatively assigned to treatment group or placebo group. Patients in the treatment group received erythromycin in divided doses for 14 days. The response was categorized as complete response, partial response, or no response. All patients were followed up for 6 weeks. RESULTS: Both groups were comparable with regard to age at presentation, sex, and average duration of disease at the time of reporting to the clinic. Upper respiratory tract infection before the appearance of skin lesions was reported in 68.8% of all patients. Complete response was observed in 33 patients (73.33%) in the treatment group and none in the placebo group (P <.0001). CONCLUSION: Oral erythromycin was effective in treating patients with pityriasis rosea.

Administration, Oral↗
PubMed2000

Low-cost technology for screening uterine cervical cancer.

We report on an illuminated, low-cost (Rs 1500 (US$ 36)) magnifying device (Magnivisualizer) for detecting precancerous lesions of the uterine cervix. A total of 403 women attending a maternal and child health care clinic who had abnormal vaginal discharge and related symptoms were referred for detailed pelvic examination and visual inspection by means of the device after the application of 5% (v/v) acetic acid. Pap smears were obtained at the same time. The results were compared with those obtained using colposcopy and/or histology. The Magnivisualizer improved the detection rate of early cancerous lesions from 60%, for unaided visual inspection, to 95%. It also permitted detection of 58% of cases of low-grade dysplasia and 83% of cases of high-grade dysplasia; none of these cases were detectable by unaided visual inspection. For low-grade dysplasia the sensitivity of detection by means of the Magnivisualizer was 57.5%, in contrast with 75.3% for cytological examination. However, the two methodologies had similar sensitivities for higher grades of lesions. The specificity of screening with the Magnivisualizer was 94.3%, while that of cytology was 99%. The cost per screening was approximately US$ 0.55 for the Magnivisualizer and US$ 1.10 for cytology.

Adolescent↗
PubMed1999

Biological behavior and etiology of inflammatory cervical smears.

Two hundred and fifty-seven consecutive women attending a major maternal and child health (MCH) center were studied clinically, colposcopically, cytologically, and microbiologically for different gynecologic infections. Out of 257 cases, 207 (80.5%) had inflammatory cervical smears, of which 183 (88.4%) were infected with one or more genital tract infections. Bacterial vaginosis (risk, 22.6-fold), chlamydia (risk, 21.6-fold), and human papillomavirus (HPV) (risk, 13.5-fold) were independently associated with inflammatory smears. In addition, significantly higher proportions of women with inflammatory smears had cervical ectopies (28.5% vs. 10.2%) and bleeding ectopies (30.9% vs. 4.1%) as compared to noninflammatory smears. Women infected with bacterial/parasitic genital infections were given specific treatment. These women were followed up at regular intervals to assess the efficacy of antimicrobial therapy. During follow-up examination, only 26 women (12.6%) showed negative smears. Sixteen women developed squamous intraepithelial lesions (SIL) during follow-up, and 163 women had persistent inflammatory smears. Multivariate analysis revealed that persistent inflammatory smears were associated with herpes simplex virus (HSV) infection, as revealed through detection of IgA antibodies to HSV (risk, 11.5-fold). Progression of SIL was associated with HPV infection (risk, 17.6 fold). Thus, inflammatory smears are associated with different types of infection, most of which do not respond to antimicrobial therapy.

Colposcopy↗