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Biomedical subjects

K Shah

Publications and source records attributed to K Shah.

At least 91 records · Page 5Linked to original sources
PubMed1996

Measles antibody in vaccinated human immunodeficiency virus type 1-infected children.

OBJECTIVES: The goals of this study were to evaluate the proportion of previously vaccinated human immunodeficiency virus (HIV) type 1-infected children with detectable postvaccination measles antibody; to assess risk factors for vaccine failure; and to evaluate the response to reimmunization. METHODS: A total of 81 perinatally HIV-infected children receiving medical care in the Bronx, New York who had previously received measles vaccine were enrolled. The Centers for Disease Control and Prevention (CDC) HIV class, lymphocyte subsets, and measles antibody were determined upon enrollment. Additional data abstracted from medical records included dates and number of prior measles vaccinations and CDC HIV class at the time of vaccination. Measles antibody was determined by microneutralization enzyme-linked immunosorbent assay (ELISA). RESULTS: The median age at time of study was 42 months (range, 9 to 168 months). Overall, 58 (72%) subjects had detectable measles antibody (microneutralization ELISA titer > 1:5). Children studied within 1 year of vaccination were more likely to have detectable measles antibody than children evaluated more than 1 year after vaccination (83% vs 52%, P < .01). The proportion of children with detectable measles antibody was higher among children with no or moderate immunosuppression compared to those with severe immunosuppression when immune status was based on CD4%. Children vaccinated at 6 to 11 months of age appeared to have a higher proportion of detectable measles antibody than those who received a first measles vaccination after age 1. Only 1 (14%) of 7 previously vaccinated children who were seronegative or had very low titers experienced a four-fold rise in measles antibody when reimmunized. CONCLUSION: These results support current recommendations to vaccinate HIV-infected children against measles. The proportion of children with detectable measles antibody among vaccinated HIV-infected children is considerably lower than in vaccinated healthy children. HIV-infected children may respond better to measles vaccine when it is administered before the first birthday. From our limited data it appears that reimmunization of previously vaccinated HIV-infected children with moderate to severe immunosuppression does not result in an antibody recall response.

Adolescent↗
PubMed1996

Recurrent respiratory papillomatosis.

Recurrent respiratory papillomatosis is an uncommon clinical disorder of the respiratory epithelium caused by HPV. It shares an identical viral etiology with genital condyloma and, in all likelihood, is transmitted at the time of birth (juvenile onset RRP) or through intimate sexual contact (adult onset RRP). Despite the precision of the surgical laser under magnification of the operating microscope, a substantial proportion of patients with RRP, adults as well as pediatric, require repeated operations at frequent intervals because of severe hoarseness and upper airway obstruction. For the management of at least a subset of patients, the efficacy of adjuvant agents (interferon is a leading choice) should be investigated in a multi-institutional clinical trial. For the potential prophylactic benefit, cesarean sections in selected high-risk expectant mothers should be considered.

Adult↗
PubMed1995

Effect of longterm misoprostol coadministration with non-steroidal anti-inflammatory drugs: a histological study.

Prostaglandins are widely used in the prevention and healing of non-steroidal anti-inflammatory drug (NSAID) induced gastric and duodenal ulcers, but their longterm effect on the human gastric mucosa is unknown. This study assessed the effect of coadministration of prostaglandins with NSAIDs on the histology of the gastroduodenal mucosa. Histological appearances (using the Sydney system) of gastric biopsy specimens from 180 patients receiving longterm NSAID treatment of whom 90 had been receiving misoprostol (400-800 micrograms/day) for one to two years were studied. Both groups of patients were comparable with regard to clinical and demographic details. There was no significant difference (p > 0.1) in the prevalence of chronic gastritis (total, corpus or antrum only) between patients receiving (36 of 90 (40%)) or not receiving misoprostol (35 of 90 (39%)). Chronic gastritis was equally associated with the presence of Helicobacter pylori, 86% and 73% (p > 0.1), respectively, in the two groups. Significantly fewer patients receiving misoprostol had reactive gastritis than those receiving only NSAIDs (8 (9%) versus 27 (30%), p < 0.01). Reactive gastritis was not associated with H pylori. Thirty nine (43%) of the misoprostol treated patients had normal histology compared with 16 (18%) receiving only NSAIDs (p < 0.01). These results show two different patterns of gastric damage in patients receiving NSAIDs, namely chronic and reactive gastritis. Misoprostol treatment was associated with a significantly reduced prevalence of reactive gastritis and it is suggested that this, along with its antisecretory action, may explain the reduced prevalence of gastroduodenal lesions when coadministered with NSAIDs.

Adult↗
PubMed1994

U-73122 does not specifically inhibit phospholipase C in rat pancreatic islets and insulin-secreting beta-cell lines.

Phospholipase C is activated in insulin secretion by islets of Langerhans and insulin-secreting beta-cells such as RINm5F and beta-TC3. We have examined the effects of the aminosteroid U-73122, a phospholipase C inhibitor, on insulin secretion and phospholipase C activation. U-73122 slightly inhibited glucose-induced insulin secretion from islets, but this effect was not specific since the structural "inactive" analogue U-73343 also inhibited insulin secretion. Likewise, in RINm5F cells, U-73122 did not inhibit glyceraldehyde-induced insulin secretion. Phospholipase C activity was assessed as the accumulation of inositol-1,4,5-trisphosphate (Ins(1,4,5)P3) measured with a competitive binding assay: U-73122 failed to inhibit glucose-induced increase in Ins(1,4,5)P3. Similarly, when the effects of U-73122 and U-73343 were measured on [3H]phosphatidylinositol hydrolysis of islets, both compounds caused a slight, non-specific inhibition of phospholipase C activity. These observations suggest that U-73122 does not specifically inhibit phospholipase C in insulin-secreting cells.

Animals↗
PubMed1994

The role of ultrasound in the management of peritonsillar abscess.

A distinction between a peritonsillar abscess and peritonsillitis is useful clinically, as the former requires surgical drainage while the latter merely requires treatment with antibiotics. To evaluate the diagnostic implications of performing ultrasonography of the tonsils in patients with clinically diagnosed peritonsillar abscess, 27 patients underwent ultrasound examination before needle aspiration of the abscess was performed. Ultrasound was able to detect peritonsillar abscess in 91 per cent of the cases (sensitivity rate), with a false negative rate of nine per cent and a false positive rate of 20 per cent. The specificity of the test was 80 per cent, and was able to differentiate abscess from peritonsillitis in 88.9 per cent. On the basis of these results we conclude that ultrasonography of the tonsils in patients thought to have peritonsillar abscess is a useful adjunct, enhancing diagnostic accuracy and reducing unnecessary surgical drainage.

Adult↗
PubMed1994

Interferon-alpha generation in mice responding to challenge with UV-inactivated herpes simplex virus.

In humans with advanced human immunodeficiency virus (HIV) infection, an interferon-alpha (IFN-alpha) response by a specialized blood mononuclear cell to herpes simplex virus (HSV) in vitro is associated with resistance to opportunistic infections. A cell type of unknown lineage, designated the natural IFN-producing cell (NIPC), has been identified preliminarily as the source of these IFNs and may have a role in other host defense functions. Earlier studies suggested the existence of analogous HSV-responsive cell populations in mice. The role specifically of IFN-alpha in the murine system, however, has not been characterized. Using IFN bioassay and neutralization with antisera against Type I IFNs and IFN-beta, we have defined the types and sources of IFNs produced by mice in response to in vivo and in vitro challenge with UV-inactivated HSV. After intraperitoneal inoculation with HSV, BALB/c and C57Bl/6 strains produced characteristically different levels of serum IFNs that appeared principally to be IFN-alpha. The response of mononuclear cells from these mice differed from that of the intact mouse. Isolated cells from bone marrow and spleen released detectable IFNs much later than did whole animals, and the IFNs produced by marrow, spleen, and peritoneal cells were usually neutralized by the anti-IFN-beta. Only bone marrow cells produced detectable amounts of IFN-alpha. Both intact mice and their cells became refractory to restimulation with similar kinetics.

Animals↗
PubMed1994

Presence of antibodies to seven human papillomavirus type 16-derived peptides in cervical cancer patients and healthy controls.

Sera from 133 cervical cancer patients and 154 healthy women (controls) from Spain and Colombia were tested in IgG-specific ELISAs for the presence of antibodies against seven peptides derived from five open-reading frames of human papillomavirus (HPV) type 16. Three of the peptides corresponded to overlapping regions of the N-terminal half of E7 protein; the other peptides corresponded to selected regions of E2, E4, L1, and L2 proteins. The prevalence of antibodies against E2 and E7 peptides was significantly different between patients and controls. The most marked differences were for E7 peptides. HPV DNA polymerase chain reaction diagnoses of cervical scrapes were available; these were correlated with serologic findings. In HPV-16 DNA-positive patients, E7 antibodies were more broadly and more strongly reactive than in other patient groups.

Age Factors↗
PubMed1994

Conformation of the oxalamide group in retro-bispeptides. Three crystal structures.

We have determined the structures of a range of peptides having the oxalamide (-NH-CO-CO-NH-) unit located at their center. The oxalamide group has the trans conformation in two retropeptides and an approximately orthogonal conformation in the peptide with Pro residues. Torsional angles about the CO-CO bond are 180 degrees in MeO-Aib-CO-CO-Aib-OMe (1), 175 degrees in MeO-L-Leu-CO-CO-L-Leu-OMe (2), and -108 and -106 degrees for the two independent molecules in the crystal of MeO-L-Pro-CO-CO-L-Pro-OMe (3), owing to steric hindrance between CO and the pyrolidine ring. Crystal data are: (1) C12H20N2O6, triclinic, space group P1, a = 6.190(1), b = 10.044(2), c = 11.989(2) A, alpha = 86.13(12), beta = 83.13(2), gamma = 80.16(2) degrees, R = 0.057 for 1646 observed reflections [magnitude of Fo > 3 sigma (magnitude of Fo)]; (2) C16H28N2O6, tetragonal, space group P4(1), a = b = 11.121(3), c = 15.775(6) A, R = 0.058 for 1216 observed reflections [magnitude of Fo > 3 sigma (magnitude of Fo)]; (3) C14H20N2O6, monoclinic space group P2(1), a = 9.556(2), b = 17.864(3), c = 9.618(2) A, beta = 104.35(1) degree; R = 0.051 for 2100 observed reflections [magnitude of Fo > 3 sigma (magnitude of Fo)].

Amides↗
PubMed1994

Enriched HLA-DQ3 phenotype and decreased class I major histocompatibility complex antigen expression in recurrent respiratory papillomatosis.

Respiratory papillomas, caused by human papillomaviruses, are benign tumors that recur following removal. We evaluated immune function and major histocompatibility complex (MHC) phenotype and expression in these patients. MHC-independent immune function appeared normal. The frequency of peripheral blood MHC class II phenotypes was highly enriched for DQ3 and DR11, one split of DR5. Class I MHC antigen expression on papilloma tissue was markedly reduced. Together, these phenomena may facilitate papillomavirus evasion of the cellular immune response.

Adult↗
PubMed1994

Impaired interferon alpha response in hairy cell leukemia is corrected by therapy with 2-chloro-2'-deoxyadenosine: implications for susceptibility to opportunistic infections.

Patients with hairy cell leukemia (HCL) are susceptible to opportunistic intracellular infections, suggesting defects in cellular immunity. Prior studies have indicated an association between failure of IFN-alpha generation by peripheral blood mononuclear cells (MNC) and susceptibility to such infections. We here present results on IFN-alpha generation in HCL patients pre- and post-therapy. Prior to treatment with 2-chloro-2'-deoxyadenosine (CdA), MNC from 24 HCL patients with active disease produced little or not IFN-alpha (geometric mean < 40 IU/ml) compared with controls (n = 140, geometric mean 1730 IU/ml, p < 0.0005). After treatment with CdA, IFN-alpha generation was studied in 16 patients, with a geometric mean value of 650 IU/ml (p < 0.0005 compared with pre-CdA levels). The severe depression of IFN-alpha generation improved progressively following CdA therapy-induced clinical remission. We propose that deficiency of IFN-alpha production may play a role in the susceptibility to intracellular infections of patients with active HCL.

Adult↗
PubMed1993

Analysis of the extractive and hydrolytic behavior of microthane poly(ester-urethane) foam by high pressure liquid chromatography.

Microthane foam, a poly(ester-urethane) (PU) used in the manufacture of Meme/Replicon breast implants, was analyzed by an HPLC method to determine whether 2,4- and 2,6-toluenediamine (TDA) were formed under a variety of physiological and nonphysiological extraction and hydrolytic conditions. At our detection limit of 20 ppb, no 2,4- or 2,6-TDA was observed in either methyl tert-butyl ether (MTBE), or aqueous buffer extracts of PU foam. The predominant extractable components identified by HPLC UV-analysis, were mixture of nonaromatic and aromatic PU fragments. Moreover, no detectable amounts of TDA were found in foam or MTBE extract of foam incubated in phosphate buffer, pH 7.4, at 37 degrees C for 5 days. By contrast, 2,4- and 2,6-TDA were found in foam and foam extracts exposed to low concentrations of either strong mineral acid or base; higher levels were found at higher acidity, treatment temperature, or durations of incubation. Moreover, 2,4- and 2,6-TDA were found in oligomers isolated by preparative HPLC and exposed to alkaline conditions. Finally, 1-2 ppm of 2,4-TDA was detected when PU foam extracts were prepared by the Snyder-Breder method, which employs acidic and alkaline conditions in the work-up procedure. Based on these findings, we suggest that published observations of 2,4-TDA formation from in vitro and ex vivo extractions of PU foam are artifacts resulting from pH effects on oligomeric PU fragments present in or extracted from the foam.

Biocompatible Materials↗
PubMed1993

Vulvar vestibulitis is rarely associated with human papillomavirus infection types 6, 11, 16, or 18.

Vulvar vestibular biopsy specimens from 31 women with clinical and pathologic findings of vulvar vestibulitis were studied using polymerase chain reaction (PCR) for the identification of human papilloma virus (HPV). The PCR technique specifically probed for HPV types 6, 11, 16, and 18. Of the 31 subjects, three were found to have HPV within the biopsy specimens; two had HPV type 11 and one had HPV 16. Five of the 31 cases had histopathologic features of koilocytosis consistent with HPV effect; three of these five were found to have HPV. The findings support the hypothesis that HPV types 6, 11, 16, and 18 are rarely associated with vulvar vestibulitis. The frequencies identified were similar to those seen with control patients. True koilocytosis is the most useful pathologic feature distinguishing HPV-related cases; it is rarely identified in typical vulvar vestibulitis. Nonspecific changes in the vestibular epithelium associated with glycogen effect should not be interpreted as koilocytosis.

Adult↗
PubMed1993

p53 gene mutations and MDM2 amplification are uncommon in primary carcinomas of the uterine cervix.

The p53 gene is the most frequently altered gene known thus far in a wide variety of human cancers. Inactivation of p53, either through mutation or through interaction with the human papillomavirus (HPV) E6 oncoprotein, is a characteristic feature of all cervical carcinoma cell lines that have been studied. These findings suggest that p53 inactivation is required for cervical carcinoma development and that HPV infection and p53 mutation may be mutually exclusive. We have studied the p53 gene in 35 primary cervical carcinomas. DNA sequence and single strand conformational polymorphism analyses were used to evaluate p53 in 27 squamous carcinomas (25 HPV-positive) and eight adenocarcinomas (four HPV-positive). A missense mutation of p53 was observed in one HPV 16-positive squamous carcinoma, demonstrating that p53 mutations can occur in combination with HPV infection. The HPV-negative tumors all lacked p53 gene mutations. The absence of p53 mutations in HPV-negative cases prompted an assessment of tumors for MDM2 gene amplification. The MDM2 gene encodes a p53 binding protein and has been found to be amplified in some human tumors lacking p53 mutations. MDM2 amplification was not identified in any of the tumors we examined, including four HPV-negative cases. Our findings show that HPV infection and p53 gene mutation are not mutually exclusive and suggest that many HPV-negative carcinomas may arise via a pathway independent of p53 inactivation.

Adenocarcinoma↗
PubMed1993

Evaluation of the home-based maternal record: a WHO collaborative study.

Thirteen centres in eight countries (Egypt, India, Pakistan, Philippines, Senegal, Sri Lanka, Democratic Yemen and Zambia) participated in the WHO collaborative study to evaluate the home-based maternal record (HBMR). The evaluation showed that use of the HBMR had a favourable impact on utilization of health care services and continuity of the health care of women during their reproductive period. When adapted to local risk conditions, their cut-off points and the available resources, the HBMR succeeded in promoting self-care by mothers and their families and in enhancing the timely identification of at-risk cases that needed referral and special care. The introduction of the HBMR increased the diagnosis and referral of at-risk pregnant women and newborn infants, improved family planning and health education, led to an increase in tetanus toxoid immunization, and provided a means of collecting health information in the community. The HBMR was liked by mothers, community health workers and other health care personnel because, by using it, the mothers became more involved in looking after their own health and that of their babies. Apart from local adaptation of the HBMR, the training and involvement of health personnel (including those at the second and tertiary levels) from the start of the HBMR scheme influenced its success in promoting maternal and child health care. It also improved the collection of community-based data and the linking of referral networks.

Continuity of Patient Care↗