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Biomedical subjects

A Chapman

Publications and source records attributed to A Chapman.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Hyperthyroidism and hypersecretion of chorionic gonadotropin in gastric adenocarcinoma].

We report a case of hyperthyroidism complicating and revealing a metastatized adenocarcinoma of the stomach with high circulating levels of human chorionic gonadotropin and its beta component. To our knowledge, this is the first reported case of a non-trophoblastic tumor with hyperthyroidism and secreting quantities of these hormones. High circulating levels of beta component in such patients have been considered to be a sign of malignancy. The mechanisms of thyroid stimulation could be related to the biological activity of certain forms of the human chorionic gonadotropin.

Adenocarcinoma↗
PubMed1994

[Renal manifestation in POEMS syndrome].

The authors report four cases of POEMS Syndrome with renal involvement. Two had renal failure and mild proteinuria. The two others had hyporeninemic hypoaldosteronism with type IV renal tubular acidosis in the first and hyperkalemia alone in the second. In the two cases, renal biopsy showed mesangial proliferation. Evolution was favourable when the plasma cell proliferation could be checked. In POEMS pathophysiology of renal involvement remains unknown. Soluble factor(s) produced by plasma cells may be responsible for most signs and symptoms perhaps as a result of increased vascular permeability.

Acidosis, Renal Tubular↗
PubMed1993

Evidence for an [Fe]-type hydrogenase in the parasitic protozoan Trichomonas vaginalis.

The hydrogenase of the pathogenic protozoan Trichomonas vaginalis was extracted and partially purified. The catalytic and spectroscopic properties of the enzyme indicate that it belongs to the class of [Fe]-hydrogenases, rather than the [NiFe]-hydrogenases. The hydrogenase activity was highly sensitive to carbon monoxide, 50% inhibition being attained by 1 microM CO. The EPR spectrum of the most active fractions from chromatography, after reduction by hydrogen and partial reoxidation under argon, showed an EPR spectrum at g = 2.10, 2.04, 2.00. This unusual spectrum is characteristic of the 'H-cluster', as seen in [Fe]-hydrogenases of anaerobic bacteria such as Clostridium spp.

Animals↗
PubMed1993

[A new cause of unexplained prolonged fever: estroprogestogen treatments, apropos of 12 cases].

Twelve female patients treated by progestogens with or without estrogens presented with prolonged (1 to 48 months) elevation of body temperature above 37 degrees C but below 38 degrees C. They had usually continued taking their temperature after and initial transitory febrile episode. Most had had multiple diagnostic tests which remained negative. Temperature became normal after cessation of hormonal treatment.

Adult↗
PubMed1992

[Does arthritis due to varicella zoster virus exist?].

Occurrence of monoarthritis or oligoarthritis during the course of zoster is exceedingly rare (three previously reported cases). In the additional case reported herein, an immunocompetent female exhibited oligoarthritis (right shoulder followed by two metacarpophalangeal joints in her right hand) a few days before developing a typical zoster eruption in the ipsilateral upper limb. Pathogenesis of zoster-related arthritis is discussed. The most likely hypothesis is infection of the joint via the nerve supply rather than via the bloodstream. Evidence in support of this mechanism includes recovery of the virus from synovial fluid specimens in a previously published case.

Arthritis, Infectious↗
PubMed1992

["Primary" pulmonary arterial hypertension associated with HIV infection. Two cases].

We report two cases of pulmonary arterial hypertension (PAHT) in HIV infected patients who never were, or had ceased to be, drug addicts. A study of these cases and a review of the literature show that this association is not fortuitous and persists after the classical causes of PAHT (pulmonary embolism, toxic factors, cirrhosis) have been excluded. The clinical features and the results of complementary cardiovascular examinations are identical with those of the so-called "primary" PAHT. The prognosis is severe: 50 percent of the patients died of the consequences of PAHT 1 year after the first clinical signs. Histology displays signs of plexogenic pulmonary arteriopathy, as in primary PAHT. In HIV patients pulmonary arterial hypertension occurs independently of the degree of immunodeficiency. Its relation with other HIV-related vasculites and their physiopathology are discussed.

Adult↗
PubMed1992

GYKI 52466 blocks the increase in extracellular glutamate induced by ischaemia.

In vivo microdialysis has been used to study the effect of pre- or post-ischaemic administration of the non-NMDA antagonist 1-(4-amino-phenyl)-4-methyl-7, 8-methyl-endioxyl-5H-2,3- benzodiazepine hydrochloride (GYKI 52466), on the increases in extracellular glutamate levels induced by 20 minutes of four vessel occlusion in rats. In control rats, ischaemia resulted in transient increases in glutamate (4 fold), aspartate (6 fold) and gamma-aminobutyric acid (GABA) (15 fold) and decreases in glutamine (0.5 fold). Intravenous administration of GYKI 52466 (10 mg kg-1 bolus followed by 10 mg kg-1 h-1 infusion) beginning 20 minutes prior to the induction of ischaemia abolished ischaemia-induced glutamate release without affecting the increases in aspartate and GABA and the decrease in glutamine. Administration of GYKI 52466 immediately post-ischaemia resulted in a more rapid return of glutamate levels to basal values.

Animals↗