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Biomedical subjects

C Womack

Publications and source records attributed to C Womack.

At least 37 records · Page 2Linked to original sources

Application of random amplified polymorphic DNA PCR for genomic analysis of HIV-1-infected individuals.

Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) is a DNA fingerprinting technique used to detect genomic polymorphisms. We employed sixteen different RAPD-PCR 10-mer primers to amplify DNA from the peripheral blood mononuclear cells (PBMC) of 80 HIV-1-infected individuals. These individuals were previously identified as either heterozygotes (+ /delta32) and homozygotes (+/+) for the CCR5 locus by PCR with gene specific primers. Four of the sixteen randomly selected RAPD primers produced distinguishable banding profiles between CCR5 (+/delta32) heterozygotes and CCR5 (+/+ ) homozygotes. Direct sequencing of some RAPD-PCR products obtained with one of the four RAPD primers that were tested yielded clearly readable, but limited sequences, which were similar to portions of the previously published sequences for (+/+ ) homozygotes (98% similarity) and (+/delta32) heterozygotes (87% similarity) of the CCR5 alleles. Thus, the RAPD-PCR technique may be useful for the identification of human molecular markers that may correlate with susceptibility to HIV-1-infection, or differences in disease progression among HIV-l-infected individuals.

Base Sequence↗

Achievable laboratory standards; a review of cytology of 99 women with cervical cancer.

The Working Party guidelines are a significant advance in the audit of the National Health Service Cervical Screening Programme (NHSCSP), the priority of which is to reduce mortality and morbidity from cervical cancer. This study was undertaken to apply the guidance on review of screening history to a series of 99 women with invasive cervical cancer diagnosed in one centre during a 9 year period. The majority (approx. 64%) of these women had not been screened within the 5 years preceding diagnosis, 25% had negative, inadequate or abnormal smears and 6% had previous treatment for cervical intraepithelial neoplasia (CIN). In four patients diagnosis was delayed. No standards are yet available to test the results of this series of women. Cervical cancer is relatively uncommon, and for data to be aggregated and compared across the UK, it is important that strict criteria are developed and applied to ensure that recruitment to the Working Party categories is uniform and not open to local interpretation. Full review and documentation of screening history should be mandatory for all women who develop cervical cancer.

Adenocarcinoma↗

An unusual cutaneous manifestation of myelodysplastic syndrome: "pseudo-Koebner phenomenon".

An unusual and hitherto unreported complication of myelodysplastic syndrome is reported: the "pseudo-Koebner phenomenon." The skin lesions were characterised by exuberant "fleshy" masses at the sites of intravenous cannulation and skin trauma, and by histological evidence of chronic inflammation with focal necrosis and abscess formation. No evidence of dermal infiltration by malignant haemopoietic cells was seen. The exact aetiopathology of the phenomenon is unclear but an inappropriate and exaggerated inflammatory response owing to aberrant mediator mechanisms that are known to occur in some cases of myelodysplastic syndrome may be implicated.

Catheterization, Peripheral↗

Epidemiology of HIV-1 infection in rural Georgia: demographic trends and analysis at the Medical College of Georgia.

We have conducted a retrospective study of 100 HIV-infected patients enrolled in an AZT monotherapy clinical study at the Medical College of Georgia (MCG) in Augusta, Georgia. When compared to the national trends, our results confirm previous studies that describe an overall increase in the burden of HIV infections among blacks, and, in particular, black women in the rural Southeast. In our cohort, infections due to homosexual contact accounted for approximately 40% of all cases while heterosexual contact and intravenous drug use (IDU) comprised 33% and 13%, respectively. Infections attributable to all other risk factors accounted for the remaining 14%. Relative to national surveillance data, we observed an increase in the prevalence of HIV infections among blacks, and heterosexually acquired infections, particularly among black women. Our analysis illustrates the dynamic nature of the current U.S. epidemic which appears to be shifting both in terms of its demographic and epidemiological profile. These data may indicate that national surveillance data may not reflect the dynamic nature of current demographic trends in HIV incidence, particularly as evidenced in the rural Southeast. This suggests that hospital or laboratory based cross-sectional studies, like ours, that analyze demographic variables of HIV-infected clinic attendees may be necessary to more accurately assess the leading edge of the HIV epidemic in rural, non-metropolitan areas.

Female↗

Pharmacokinetics and pharmacodynamics of metrifonate in humans.

We studied the pharmacokinetics and pharmacodynamics [red blood cell (RBC) cholinesterase (ChE) inhibition] of metrifonate (MTF) and its active anti-ChE metabolite, dichlorvos (DDVP) in Alzheimer's disease (AD) patients and normal controls after oral MTF. In Study I conducted for 6 h, 3 patients with prior MTF exposure received oral MTF (7.5 mg/kg). Plasma ChE inhibition peaked to 78.5 +/- 12.3% at 15 min, while maximum RBC ChE inhibition seen at 1 h was 61.0 +/- 11.0%. Plasma ChE inhibition was unchanged at 6 h, whereas RBC ChE recovered with a t1/2 of 7.0 +/- 3.5 h. In Study II, 6 patients and 6 controls with no prior MTF exposure were given oral MTF. Mean plasma t1/2 of MTF was 2.3 +/- 0.3 h with ChE recovery t1/2 of 9.0 +/- 3.3 (plasma) and 26.6 +/- 15.2 days (RBC) after 7.5 mg/kg MTF. The short drug t1/2, long ChE recovery t1/2 and the achievement of high ChE inhibition levels with minimal side effects suggest the potential use of this drug for Alzheimer therapy.

Administration, Oral↗

A study of the local toxicity of agents used for variceal injection sclerotherapy.

Injection sclerotherapy is widely used in the treatment of oesophageal varices. However, few studies have compared the local toxicity of sclerosant agents which may be important if serious local complications are to be avoided. In this study the depth of injury caused by submucosal injection of increasing concentrations of sodium tetradecyl sulphate, polidocanol, 5% ethanolamine oleate and 5% varicosid in rabbits stomach, has been compared by histopathological examination. Macroscopic ulceration was seen in 14.6% of injection sites. Increasing concentrations of sodium tetradecyl sulphate and polidocanol produced increasingly extensive microscopic inflammation. Five percent varicosid caused more inflammation than 5% ethanolamine and only 3% polidocanol and 5% varicosid caused full thickness inflammation. Only 5% ethanolamine produced inflammation consistently confined to the mucosa and submucosa. On the basis of this study we feel that 5% ethanolamine is the most suitable agent for injection sclerotherapy.

Animals↗

Primary malignant melanoma of the gall bladder.

A case of primary malignant melanoma of the gall bladder is reported, in which a 29 year old man presented with acute cholecystitis which led to perforation of the gall bladder and biliary peritonitis. To help in the differentiation between primary and secondary malignant melanoma in the gall bladder and to overcome some of the difficulties posed by the clinical identification of what is often a small or relatively inaccessible primary tumour, it is suggested that certain criteria should be fulfilled before primary melanoma is diagnosed. (i) Tumours must be solitary and arise from the mucosal surface of the gall bladder; (ii) they must either be papillary or polypoid; (iii) they must either display junctional activity or have any other primary sites excluded by history taking, examination, and investigation. If these criteria are applied to the published case reports of primary malignant melanoma, only six cases, including the present one, can be regarded as true primary tumours.

Adult↗

Electrohydraulic lithotripsy of gall stones--in vitro and animal studies.

Electrohydraulic lithotripsy of human gall stones was investigated in vitro in a bath of saline and in a saline perfused bile duct. The technique was effective--only two stones could not be shattered. Electrohydraulic lithotripsy power requirement correlated with mechanical strength of stones, but not with biochemical composition. A trend toward higher power requirement was recorded with larger stones and stones over 2 cm in diameter could not be fragmented. Safety studies indicated that electrohydraulic lithotripsy was safe, provided the probe tip was not in contact with the bile duct wall. In vivo studies did not show any late effects after 10 days. Electrohydraulic lithotripsy is likely to be useful in the management of biliary calculi.

Animals↗

Diagnosis of molar pregnancy and persistent trophoblastic disease by flow cytometry.

Histopathological assessment and flow cytometric analyses were carried out on 32 placentas (representative of each trimester) and 88 molar pregnancies. Three first trimester placentas were triploid, and the remaining 29 placentas were diploid. Of the 88 cases originally diagnosed as molar pregnancies, 26 were triploid (two complete moles, 20 partial moles, and four hydropic abortions); 59 were diploid (46 complete moles, 10 partial moles, three hydropic abortions); one was tetraploid (partial mole); and two were DNA aneuploid (one partial mole, one complete mole). A significantly increased hyperdiploid fraction (a measure of cell proliferation) was detected in diploid complete moles (p less than 0.0001) and cases of persistent trophoblastic disease (p less than 0.001) when compared with diploid placentas and diploid partial moles. All seven cases of established persistent trophoblastic disease, for which follow up was available, were diploid and showed high hyperdiploid fractions within the range for diploid complete moles. These findings suggest that flow cytometric DNA measurements may be an important aid in the diagnosis of molar pregnancy. The high degree of cell proliferation found in this study may explain the premalignant potential of complete hydatidiform moles.

Diploidy↗