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Biomedical subjects

H Gilbert

Publications and source records attributed to H Gilbert.

At least 19 recordsLinked to original sources
PubMed1994

Angelman syndrome associated with a maternal 15q11-13 deletion of less than 200 kb.

Angelman syndrome (AS) is a neurogenetic disorder arising from a lack of genetic contribution from the maternal chromosome 15q11-13. To date, the AS critical region has been defined by an inherited deletion of approximately 1.5Mb, spanning the 3-21 (D15S10), LS6-1 (D15S113) and GABRB3 loci. We have identified an individual with the typical features of AS who has a deletion of the maternal chromosome which encompasses LS6-1, but does not extend to either flanking marker. This deletion, initially detected by (CA)n repeat analysis, was further characterised by fluorescence in situ hybridisation (FISH) using cosmids derived from a 260 kb LS6-1 yeast artificial chromosome (YAC). Neither end cosmid from this YAC clone falls within the deletion, suggesting that the minimal AS region is less than 200 kb. We also studied three loci within 15q11-13 which detect parent-of-origin specific DNA methylation imprints, and found that both normal maternal and paternal patterns were present in this patient.

Angelman Syndrome↗
PubMed1992

Survey of Bacteroides fragilis group susceptibility patterns in Canada.

The in vitro activities of penicillin, clindamycin, chloramphenicol, metronidazole, piperacillin, piperacillin-tazobactam, ticarcillin, ticarcillin-clavulanate, ampicillin-sulbactam, cefoxitin, ceftizoxime, cefotetan, moxalactam, and imipenem against 348 Bacteroides fragilis group isolates collected from six Canadian cities during 1990 were determined by the National Committee for Clinical Laboratory Standards (NCCLS) agar dilution technique. All isolates were susceptible to chloramphenicol, metronidazole, piperacillin-tazobactam, and imipenem. For the other antibiotics tested, the following resistance rates were observed: penicillin, 97%; clindamycin, 9%; piperacillin, 19%; ticarcillin, 31%; ticarcillin-clavulanate, 0.28%; ampicillin-sulbactam, 0.85%; cefoxitin, 26%; ceftizoxime, 15%; cefotetan, 53%; and moxalactam, 17%. Susceptibility profiles to beta-lactam antibiotics varied among the different species tested: B. fragilis and Bacteroides vulgatus demonstrated lower resistance rates than Bacteroides distasonis and indole-positive Bacteroides thetaiotaomicron and Bacteroides ovatus. Ceftizoxime results should be interpreted cautiously, because the MICs obtained with the recommended NCCLS control strain were lower than expected.

Anti-Bacterial Agents↗
PubMed1989

Activation of human neutrophil NADPH-oxidase in vitro by the catalytic fragment of protein kinase-C.

Phorbol ester treatment of intact neutrophils both stimulates protein kinase C (PK-C) and causes the rapid proteolytic conversion to a cytosolic, co-factor independent fragment, protein kinase M (PK-M). In intact neutrophils, phorbol ester treatment activates the NADPH-oxidase, the enzyme responsible for the oxidative burst. Addition of purified PK-M to resting neutrophil light density membranes activated the NADPH-oxidase in the presence of PS, ATP and Mg2+. A 3.5-fold greater stimulation of oxidase (ca. 25 nmoles O2-/min/mg membrane protein) was obtained with comparable PK-M concentrations to that observed with the reconstituted PK-C system, and approximately 1/3 that obtained with arachidonic acid (AA) or SDS. In contrast to the reconstituted system using PK-C, PMA and Ca++ were neither required nor affected activity. The effect of PS was unexpected, since PK-M does not require phospholipids for enzymatic activity, and likely represents the action of PS on the oxidase itself or on another component in the plasma membrane fraction. Our studies demonstrate for the first time that purified PK-M permits reconstitution of a physiologic phorbol ester response.

Adenosine Triphosphate↗
PubMed1985

Massive hepatic necrosis after chemotherapy withdrawal in a hepatitis B virus carrier.

A chronic hepatitis B virus (HBV) carrier with diffuse nodular transformation of the liver and malignant lymphoma in the lymph nodes and spleen developed massive hepatic necrosis and died three weeks after the third cycle of chemotherapy. Immunosuppressive drug treatment may favor replication of HBV, resulting in massive hepatocyte destruction when the immune response recovers following withdrawal of chemotherapy. This outcome must be considered in patients with chronic hepatitis B who are treated with a course of prednisone followed by antiviral therapy as well as in HBV carriers following chemotherapy for malignant disease.

Antineoplastic Agents↗
PubMed1984

Multiple evanescent white dot syndrome. I. Clinical findings.

We examined 11 young patients with unilateral ocular findings that included multiple white dots at the level of the retinal pigment epithelium (RPE) or the deep retina, vitreal cells, RPE granularity in the macula, reduced visual acuity, electroretinogram (ERG) and early receptor potential (ERP) amplitudes, and fluorescein leakage from disc capillaries and late staining of the RPE. Recovery of visual function included a dramatic improvement in ERG and ERP amplitudes over several weeks. The etiology of this syndrome remains uncertain; there is no definite evidence of systemic involvement.

Adolescent↗
PubMed1983

Increased serum procollagen III aminoterminal peptide in myelofibrosis.

Myelofibrosis has been shown to involve an increase in type III collagen in the marrow. The aminoterminal procollagen III (PC III) peptide fragment is released during the production of PC III by fibroblasts and its serum level is therefore a marker for type III collagen synthesis. Using a recently developed sensitive radioimmunoassay, serum levels of PC III peptide were measured in 30 patients with myeloproliferative disease and 23 normal volunteers. Levels were found to be elevated above normal values in patients with polycythemia vera, even more elevated in patients with polycythemia and evidence of secondary myelofibrosis with myeloid metaplasia, and most strikingly elevated in patients with agnogenic myeloid metaplasia and severe marrow fibrosis. There was a significant association between serum levels of PC III peptide and the extent of reticulin fibrosis in bone marrow biopsies. Serum PC III level appears to be a quantitative marker for myelofibrosis.

Adult↗
PubMed1982

Rapid analysis of immunoglobulin isoelectric focusing patterns with cellulose nitrate sheets and immunoperoxidase staining.

Immunoglobulins which have been focused to their isoelectric points in thin-layer polyacrylamide gels can be transferred by diffusion to the surface of cellulose nitrate sheets with retention of the original focusing patterns. IgG can be detected with peroxidase-linked antiserum. Unlike polyacrylamide gel, cellulose nitrate offers no permeability barrier, and so washing times are reduced from days to minutes. Thus small quantities (less than 1 microgram) of IgG may be visualized within 24 h of isoelectric focusing. In addition after immobilization on cellulose nitrate, immunoglobulin reactivity with antigens, including those of high molecular weight, may be analysed.

Animals↗
PubMed1977

The management of extramedullary disease in acute leukemia with therapeutic radiations.

The authors reviewed 181 patients who received local radiation therapy for the prevention or control of extramedullary disease resulting from acute leukemia. 126 had acute lymphocytic leukemia and 55 had acute granulocytic leukemia. They were treated over a 18-year period of time with different forms of chemotherapy. Most had not received prophylactic CNS radiation therapy. Patients were evaluated for local control until death or hematologic relapse intervened. More than 80% of patients with clinical ALL meningeal leukemia had a successful response to doses over 1000 rads. This same response was not apparent in AML. More than 80% of clinical non-CNS extra medullary leukemia was controlled with doses of 600 rads or greater. Only one patient with extra-medullary relapse is still alive. The authors feel that lower preventative doses of radiation to the CNS are compatible with similar control rates, based on their own data and other suggestive data.

California↗