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Biomedical subjects

V A Hill

Publications and source records attributed to V A Hill.

9 recordsLinked to original sources
PubMed1995

Cutaneous T-cell lymphoma presenting with atypical perianal lesions.

A patient with an atypical presentation of cutaneous T-cell lymphoma is reported. For many years, there were perianal lesions only, which were initially diagnosed as a non-specific severe perianal dermatitis, possibly due to psoriasis. There was little response, however, to potent topical steroids. Further patch and plaque lesions then developed elsewhere and plaque stage mycosis fungoides was diagnosed, allowing effective treatment with superficial radiotherapy and PUVA to be given. The difficulties that may be encountered in the diagnosis of cutaneous T-cell lymphoma are discussed.

Anus Neoplasms↗
PubMed1994

Cutaneous necrosis associated with the antiphospholipid syndrome and mycosis fungoides.

The development of extensive cutaneous necrosis in a patient with tumour-stage mycosis fungoides is described. Skin biopsies showed a lymphomatous infiltrate, and thrombosis of dermal blood vessels. Investigation revealed the presence of anticardiolipin antibodies, a lupus anticoagulant, and low free protein S, which contributed to a prothrombotic state. Antiphospholipid antibodies have been detected in non-Hodgkin's lymphoma, but clinical manifestations are uncommon. Such autoantibodies may be produced by neoplastic lymphoid cells. The frequency with which antiphospholipid antibodies occur in mycosis fungoides is currently unknown.

Antiphospholipid Syndrome↗
PubMed1993

Sample preparation techniques.

Evidentiary false positives are caused by passive exposure to drugs in the environment rather than by active use of drugs. The avoidance of such positives is essential for both hair and urine analysis. Hair analysis enjoys the advantage over urinalysis in having a number of approaches for making this distinction. These include: methylene blue staining of the hair specimen for selecting the appropriate wash solvent; application of hair digestion techniques for the complete release of chemically unaltered analytes; the determination of three diagnostic ratios from wash and digestion data; the measurement of metabolite:drug ratios; the use of cut-off levels setting the limits for passive endogenous drug exposure; reproducibility of results (including segmental analysis) with a newly collected hair specimen; and the reporting of results as either negative, positive, or contaminated. Our sample preparation procedures have been effectively applied to the analyses of nearly 200,000 specimens, i.e. to approximately one million drug analyses for cocaine, opiates, methamphetamine, phencyclidine or marijuana. On the basis of this experience we conclude that hair analysis is a safe and effective method for workplace drug testing.

Aged↗
PubMed1992

Detection of benzodiazepines in human hair by radioimmunoassay.

OBJECTIVE: In this preliminary investigation, we sought to determine whether a standard benzodiazepine radioimmunoassay (RIA) could detect three benzodiazepines in human hair. DESIGN: Hair samples of 20-50 strands (minimum 10 mg) were cut from eight patients receiving diazepam, two patients receiving alprazolam, three patients receiving lorazepam, and two negative controls. Samples were treated with ethanol and phosphate buffer washes at 37 degrees C to remove external contamination. The protein hair matrix was destroyed using proprietary procedures, then analyzed with Abuscreen RIA designed to detect various benzodiazepines and their metabolites, using oxazepam as a reference standard. SETTING: Patients were hospitalized in a locked psychiatric facility. PATIENTS: Twelve patients with chronic psychiatric conditions who had received therapeutic dosages of benzodiazepines for 1-11 months were included in the sample. One outpatient who reported heavy prior diazepam use was also included. MAIN OUTCOME MEASURE: Detection of benzodiazepines was well above a 1.5 ng/10 mg cutoff level with the Abuscreen assay. RESULTS: Diazepam was readily detected, but alprazolam and lorazepam were not detected. CONCLUSIONS: There is no test that can currently determine duration and extent of prior benzodiazepine use. Hair analysis for diazepam offers a potential, new clinical and research tool for characterizing prior level and extent of usage.

Adult↗
PubMed1984

Serum thyroglobulin, a monitor of differentiated thyroid carcinoma in patients receiving thyroid hormone suppression therapy: concise communication.

Serum thyroglobulin levels were obtained in 86 patients who had undergone thyroidectomy and I-131 ablation for differentiated thyroid cancer, and who were receiving or had recently discontinued thyroid hormone suppression therapy. Excellent correlation was observed between serum thyroglobulin levels in patients receiving thyroid hormone suppression therapy and I-131 imaging studies. Serum thyroglobulin levels equal to or below 20 ng/ml indicate the absence of thyroid carcinoma, and values exceeding 60 ng/ml were indicative of active thyroid cancer but may include some patients without clinical evidence of disease. Intermediate serum thyroglobulin levels were observed in a small number of patients with postsurgical thyroid remnants or active disease. Serum thyroglobulin levels are of considerable value in monitoring the activity of thyroid cancer in patients who are receiving thyroid hormone suppression therapy.

Antithyroid Agents↗
PubMed1978

Anomalous vitamin E effects in mitochondrial oxidative metabolism.

Three different vitamin E effects, suggestive of specific antioxidant effects, were discovered in the protective action of vitamin E against respiratory decline (a decrease in mitochondrial respiration attributed to a "leakage" of electron transport radicals). No correlation was found between respiraotry decline and random lipid peroxidation. The mechanisms behind two of the three atypical vitamin E effects were defined. Both involve an artifact in the TBA assay for lipid peroxidation. This artifact occurs when TBA assays are carried out in the presence of sucrose and acetaldehyde; the latter is produced from ethanol, the solvent used to add vitamin E to preparations. The artifact in the TBA assay for peroxidations appears also to be responsible for differing interpretations of the hepatotoxic effect of ethanol.

Acetaldehyde↗
PubMed1978

Antioxidant effects in the development of Ehrlich ascites carcinoma.

The effect of Ehrlich ascites tumor growth on selenium-turnover rates and selenium-75 distribution in liver, kidney, and immunological tissues (spleen, thymus, and lymph nodes) was investigated in Swiss Webster mice that had been prelabeled with selenium-75. Ehrlich ascites tumor caused a decrease in the selenium-75 content of liver, kidney, and thymus; it also decreased the rate of the total-body selenium-turnover. In liver, depletion of selenium-75 was almost as great as that produced by a selenium and vitamin E-deficient diet. When mice had been fed an antioxidant-deficient diet, considerable quantities of selenium-75 were accumulated by the tumor; the specific activity of the tumor increased 9-fold over that in antioxidant-supplemented mice. The same diet produced a premature, and in some cases drastic, contraction in tumor volume. The possible significance of tumor-induced antioxidant deficiencies to the etiology of certain paraneoplastic syndromes is discussed.

Animals↗
PubMed1975

Novel interference in thiobarbituric acid assay for lipid peroxidation.

The thiobarbituric acid test for lipid peroxidation, when applied to a mixture of acetaldehyde and sucrose, produces a 532 nm aborbing chromogen which is indistinguishable from that formed by malonaldehyde and thiobarbituric acid. Unless special procedures are adopted to correct for this effect, the combined action of acetaldehyde and sucrose interferes seriously with the assay of lipid peroxidation reactions, notably those implicated in alcohol-induced liver injuries. However, this unusual thiobarbituric acid effect also can be used as a sensitive method for the detection of acetaldehyde.

Acetaldehyde↗