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H Gordon

Publications and source records attributed to H Gordon.

At least 37 records · Page 2Linked to original sources
PubMed1995

Computerized consensus diagnosis: a classification strategy for the robust analysis of MR spectra. I. Application to 1H spectra of thyroid neoplasms.

We introduce and apply a new classification strategy we call computerized consensus diagnosis (CCD). Its purpose is to provide robust, reliable classification of biomedical data. The strategy involves the cross-validated training of several classifiers of diverse conceptual and methodological origin on the same data, and appropriately combining their outcomes. The strategy is tested on proton magnetic resonance spectra of human thyroid biopsies, which are successfully allocated to normal or carcinoma classes. We used Linear Discriminant Analysis, a Neural Net-based method, and Genetic Programming as independent classifiers on two spectral regions, and chose the median of the six classification outcomes as the consensus. This procedure yielded 100% specificity and 100% sensitivity on the training sets, and 100% specificity and 98% sensitivity on samples of known malignancy in the test sets. We discuss the necessary steps any classification approach must take to guarantee reliability, and stress the importance of fuzziness and undecidability in robust classification.

Adenocarcinoma, Follicular↗
PubMed1995

Acetylcholine receptor clustering in C2 muscle cells requires chondroitin sulfate.

Proteoglycans have been implicated in the clustering of acetylcholine receptors (AChRs) on cultured myotubes and at the neuromuscular junction. We report that the presence of chondroitin sulfate is associated with the ability of cultured myotubes to form spontaneous clusters of AChRs. Three experimental manipulations of wild type C2 cells in culture were found to affect both glycosaminoglycans (GAGs) and AChR clustering in concert. Chlorate was found to have dose-dependent negative effects both on GAG sulfation and on the frequency of AChR clusters. When extracellular calcium was raised from 1.8 to 6.8 mM in cultures of wild-type C2 myotubes, increases were observed both in the level of cell layer-associated chondroitin sulfate and in the frequency of AChR clusters. Culture of wild-type C2 myotubes in the presence of chondroitinase ABC eliminated cell layer-associated chondroitin sulfate while leaving heparan sulfate intact and simultaneously prevented the formation of AChR clusters. Treatment with either chlorate or chondroitinase inhibited AChR clustering only if begun prior to the spontaneous formation of clusters. We propose that chondroitin sulfate plays an essential role in the initiation of AChR clustering and in the early events of synapse formation on muscle.

Cells, Cultured↗
PubMed1995

Management of female genital mutilation: the Northwick Park Hospital experience.

OBJECTIVE: To outline the problems associated with female genital mutilation and to highlight the need for deinfibulation before delivery. DESIGN: A review of women attending a newly established African Well Woman Clinic. Age at infibulation, gravidity of clinic attenders and adequacy of introitus for management of labour were assessed. SETTING: Northwick Park Hospital, Harrow, Middlesex. SUBJECTS: Fifty women attending a newly established African Well Woman Clinic, of whom 13 were nulliparous, 14 were primigravid and 23 were multigravid. RESULTS: The average age at which infibulation had occurred was 6.7 years. At the time of clinic attendance the mean age of pregnant and nonpregnant patients was 26 and 23.3 years, respectively. Of the 14 primigravid patients, only 50% had an adequate introitus to allow management of the first and second stages of labour. Five had deinfibulation performed antenatally or at delivery. Ninety-three percent of the primigravid patients and 74% of the multigravid patients had a vaginal delivery. CONCLUSIONS: We believe that the Northwick Park Hospital management policy for infibulated women closely mirrors the cultural practices in Somalia. The policy also improves obstetric management of infibulated patients. Twenty-six percent of referrals were of nonpregnant women, and this practice is to be encouraged.

Adolescent↗
PubMed1993

Association of familial Duane anomaly and urogenital abnormalities with a bisatellited marker derived from chromosome 22.

We report a spectrum of defects that were found in an 18-year-old girl who presented for investigation of primary amenorrhea. The patient was found to have Duane anomaly, left renal agenesis, absent uterus, bilateral sensorineural deafness, and bilateral preauricular skin tags and sinuses. Investigation of her family showed that her brother also had Duane anomaly, right renal agenesis, sensorineural deafness, and preauricular skin tags and that their father had preauricular skin tags. Cytogenetic analysis, including in situ hybridisation of peripheral blood lymphocytes, demonstrated a supernumerary bisatellited marker chromosome derived from the region of chromosome 22pter-q11 in the affected individuals. Our findings indicate that a gene or genes located in the region of chromosome 22pter-q11 may be associated with the Duane anomaly and the development of the urogenital tract.

Adolescent↗
PubMed1993

A muscle cell variant defective in glycosaminoglycan biosynthesis forms nerve-induced but not spontaneous clusters of the acetylcholine receptor and the 43 kDa protein.

Myotubes of the C2 mouse muscle cell line form clusters of ACh receptors (AChRs) at apparently random sites along their length when cultured alone, and near sites of nerve-muscle contact when cocultured with neurons. We find in aneural cultures that myotubes of a C2 variant, S27, which is defective in glycosaminoglycan synthesis, express the AChR on their surface, but do not form clusters. S27 cells in aneural cultures also express the 43 kDa protein but do not cluster it. The altered distribution of laminin and collagen IV on the surface of S27 myotubes suggests that the basal lamina is abnormal. Neither the addition of exogenous proteoglycans or conditioned medium from wild-type C2 cells, nor the growth of S27 cells on substrates rich in basal lamina elements caused clusters to appear on S27 myotubes in aneural cultures. When cultured with primary neurons, however, S27 myotubes formed large clusters of the AChR near sites of neurite contact. The clusters were coincident with patches of the 43 kDa protein. Prelabeling experiments indicate that at least some AChRs in the clusters arise through aggregation. Although Torpedo agrin induces AChR clusters on C2 myotubes, it does not do so on S27 cells. Our experiments suggest that the spontaneous formation of clusters of AChRs and the 43 kDa protein in aneural cultures of myotubes depends upon the normal synthesis of muscle proteoglycans, and that nerve-induced clustering does not. Thus, there appear to be multiple mechanisms for the formation of AChR clusters.

Agrin↗
PubMed1992

Cooperation between the products of different nuclei in hybrid myotubes produces localized acetylcholine receptor clusters.

Cultured myotubes form clusters of acetylcholine receptors (AChRs) spontaneously and at sites of nerve-muscle contact. To investigate the cellular mechanisms by which spontaneous clusters are formed, we have made hybrid myotubes between a mouse muscle cell variant, S27, that does not cluster AChRs, and one that does not make AChRs. We have also made hybrid myotubes using S27 and quail muscle cells. In both cases, clusters of AChRs were found near the non-S27 nuclei; in the case of the interspecific hybrids, mouse AChRs were associated with extracellular matrix components contributed by the quail nuclei. Our results suggest that AChRs made by one nucleus can be clustered by localized extracellular matrix produced by a different nucleus and provide an example of nuclear cooperation between the products of different nuclei within multinucleated muscle fibers.

Animals↗
PubMed1992

Retrospective maternal mortality case ascertainment in West Virginia, 1985 to 1989.

OBJECTIVE: The death of women from pregnancy-related causes remains a threat to national maternal and child health. Maternal deaths as persistent, albeit rare occurrences are overlooked if vital registration systems are relied on to report such deaths. STUDY DESIGN: Live birth records were matched with death records for women of reproductive age to detect if a woman died within 1 year of delivery. The data for potential cases were reviewed by committee and classified as maternal and nonmaternal deaths. RESULTS: Of all linked birth-death records, 32% were related to pregnancy: 81% were directly related to pregnancy and 19% were indirectly related to pregnancy. The most frequent causes of death were hemorrhage and embolism. Thirty-eight percent of the women were transferred to tertiary hospitals before death. The case ascertainment through this study improved maternal death detection by 100% over official vital statistics. CONCLUSION: Enhanced maternal mortality surveillance increased the detection of maternal death in West Virginia. Case review of these deaths yielded important information useful in shaping the state's perinatal system.

Adult↗
PubMed1992

Prelabour rupture of the membranes at term and unfavourable cervix; a randomized placebo-controlled trial on early intervention with intravaginal prostaglandin E2 gel.

Fifty nine women with prelabour rupture of membranes, unfavourable cervix and no evidence of infection or fetal distress were randomized formally to receive prostaglandin E2 (3mg) gel or sterile K-Y Jelly intravaginally. Conservative expectant management was followed for the next 24 hours. The subsequent management of the labour followed departmental protocol. The women who received prostaglandin went into labour sooner and were delivered earlier but the duration of labour was not significantly different. There were no significant differences in other clinical outcomes. There was 1 case of uterine rupture in the prostaglandin group. We conclude that early intervention with prostaglandin E2 gel intravaginally confers no advantage compared with conservative management except for earlier confinement in this group of patients.

Administration, Intravaginal↗
PubMed1992

Chlamydia trachomatis antigen prevalence among pregnant women in West Virginia.

During 1990, more than 2,100 women who received prenatal care at one of four clinics which serve 11 West Virginia counties, were screened for chlamydial antigen. Overall, 5.6 percent of the women screened had positive antigen tests and 90 percent of these individuals were under the age of 25. The prevalence of chlamydia was different at three geographic sites with the highest rate of positive antigen test being 9.4 percent at one site. These findings led to a careful analysis of the prevalence of this disease among women who lived in rural areas versus those who lived in urban areas. This detailed analysis involved only patients seen in the Grafton and Morgantown clinics, and revealed a tendency for most positive antigen tests to occur among women with urban addresses. Our study indicates that a substantial chlamydial problem exists among pregnant women of young age. Although screening all pregnant women for chlamydia may not be cost effective, knowing which individuals are at highest risk may help target limited screening for these patients.

Adult↗
PubMed1991

Spontaneous carotid-cavernous fistulae in Ehlers-Danlos syndrome Type IV. Case report.

Spontaneous bilateral carotid-cavernous fistulae and cervical artery dissection is reported in a 20-year-old woman with Ehlers-Danlos syndrome Type IV. The clinical features of 16 previously published cases of spontaneous carotid-cavernous fistulae associated with Ehlers-Danlos syndrome Type IV are reviewed, for a total of 17 cases. The mean age of the 14 women and three men was 31.6 years. Only direct fistulae were encountered. Diagnostic neuroangiography carried morbidity and mortality rates of 36% and 12%, respectively; neuroradiological treatment resulted in death in one of six patients. The possible value of desmopressin in the management of these patients is discussed. In view of the risks of arterial puncture and surgery, the authors emphasize the importance of early recognition of Ehlers-Danlos syndrome.

Adult↗
PubMed1991

A staffing standard proposal for patient and non-patient areas in hospitals. Philadelphia Chapter of the National Executive Housekeepers Association.

The Philadelphia Chapter of N.E.H.A. submits the following proposal for publication. We feel very strongly about the need to formalize some staffing standards for hospitals and all related healthcare facilities. The incentive comes from the current trend in administrative philosophies to "do more with less." The less means less for the support departments whose contribution is viewed most times as less worthy because we do not directly generate revenue. Oddly enough, the revenue generators cannot make money without the non-revenue generators.

Efficiency↗
PubMed1990

Negative control of the helix-loop-helix family of myogenic regulators in the NFB mutant.

We have characterized a nondifferentiating mouse muscle cell line, NFB, that represses the activity of the helix-loop-helix (HLH) family of myogenic regulators, yet expresses sarcomeric actins. The NFB MyoD gene is silent, but can be activated upon transfection of a long terminal region-controlled chicken MyoD cDNA, resulting in myogenesis. When NFB cells are fused with H9c2 rat muscle cells in heterokaryons, the level of rat MyoD transcripts declines. Thus, the stoichiometry of MyoD and the putative repressor controls myogenesis. Although NFB cells express myogenin and Myf-5 transcripts, the activity of these regulators is also repressed:myogenesis is not induced in 10T1/2 fibroblasts and is repressed in L6 muscle cells upon fusion with NFB cells. We conclude that the myogenic HLH regulators are not required for sarcomeric actin gene activation and that myogenesis is subject to dominant-negative control.

Actins↗