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Biomedical subjects

J Leonard

Publications and source records attributed to J Leonard.

At least 127 records · Page 7Linked to original sources
PubMed1987

Structure and function of the human interleukin 2 receptor gene.

The gene encoding the human Interleukin 2 (IL-2) receptor consists of 8 exons spanning more than 25 kilobases on chromosome 10. Exons 2 and 4 were derived from a gene duplication event and unexpectedly also are homologous to the recognition domain of human complement factor B. Receptor gene transcription is initiated at two principal sites in normal activated T cells. Adult T cell leukemia cells infected with HTLV-I show activity at both of these sites, but also at a third transcription initiation site. Resting T cells do not contain detectable IL-2 receptor mRNA. Within 1 hour after stimulation with phytohemagglutinin (PHA), a large, presumably nuclear precursor RNA species is seen, which then gradually disappears. Mature IL-2 receptor mRNA forms appear within 8 hours after stimulation, reach peak levels between 8 and 24 hours, and then decline. Thus in PHA-activated lymphocytes the rise and fall in IL-2 receptor mRNA levels precede by more than 24 hours the peak and decline of IL-2 receptor protein expression occurring at the cell surface. Nuclease S1-protection assays indicate that IL-2 receptor mRNAs may differ in length due to the use of three different polyadenylylation signals. Further, these assays demonstrate the presence of transcripts that lack a 216-base segment within the protein-coding region and thus do not encode a functional IL-2 receptor. Nuclear transcription assays indicate that the increase in IL-2 receptor mRNA is reflected at the level of transcription. Thus, IL-2 receptor gene regulation controls IL-2 receptor expression at the cell surface and is intimately linked to the control of T-cell proliferation.

DNA↗
PubMed1986

Sensitivity and specificity of IgA-class antiendomysial antibodies for dermatitis herpetiformis and findings relevant to their pathogenic significance.

The specificity and sensitivity of the recently reported IgA-class antiendomysial antibody test for gluten-sensitive enteropathy were evaluated in four double-blind studies involving the sera of fifty-seven patients with dermatitis herpetiformis who were not on a gluten-free diet and ninety-seven assorted control sera. The control sera provided by the four centers included the sera of nineteen patients with dermatitis herpetiformis and two with celiac disease who were on a gluten-free diet, the sera of five normal subjects with human lymphocyte antigens (B8 locus), the sera of thirteen patients with linear IgA bullous dermatosis, and fifty-eight other control sera, mostly from patients with other bullous diseases and other dermatoses. The frequency of IgA antiendomysial antibody in these coded studies was zero of ninety-seven control sera and thirty-four of fifty-seven sera (60%) from patients with dermatitis herpetiformis who were not on a gluten-free diet. The pathogenic role of IgA antiendomysial antibodies in dermatitis herpetiformis and celiac disease is suggested not only by their high degree of disease sensitivity and specificity but also by their formation in response to gluten challenge, their appearance before gut changes, and the in vitro binding of gliadin to the antiendomysial antibody antigen sites. These and other findings in this study and in the literature suggest that gluten-sensitive enteropathy is immunologically mediated and that IgA antiendomysial antibodies play a significant pathogenetic role.

Animals↗
PubMed1985

[Not Available].

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France↗
PubMed1984

Genital tract examinations and zona-free hamster egg penetration tests from men exposed in utero to diethylstilbestrol.

Because most men with prenatal exposure to diethylstilbestrol (DES) are still young and have not attempted to father children, its reproductive effects are uncertain. In a previous pilot study, we had noted an association between in utero DES exposure and reduced penetration of zona-free hamster eggs by sperm. To test these findings in a controlled manner, we performed physical examinations on 51 men with in utero DES exposure and 29 unexposed men and evaluated the penetration of zona-free hamster eggs by their sperm. Epididymal cysts or abnormalities of the prostate, testicle, or penile meatus were present in 37% of men with in utero DES exposure, versus 4% of nonexposed men (P less than 0.001). The mean proportions of penetrated eggs were 25% after in utero DES exposure and 29% in the nonexposed group (P greater than 0.57). The genital abnormalities related to DES exposure were not related to reduced egg penetration. We conclude that in utero exposure to DES is not related to a significant change in the penetration of zona-free hamster eggs by sperm.

Abnormalities, Drug-Induced↗
PubMed1983

[Not Available].

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Historiography↗
PubMed1981

Possible relationship between in utero diethylstilbestrol exposure and male fertility.

Seventeen men who were exposed in utero to diethylstilbestrol (DES), 12 non-DES-exposed volunteers, and 11 fertile control subjects were evaluated by physical examination, seminal fluid analysis, and sperm penetration assay (SPA). Fourteen of the 17 male subjects exposed to DES in utero and two of the 12 non-DES-exposed volunteers had SPAs of less than 14% and qualified as infertile by the criteria of this test. All 11 fertile control subjects had demonstrated SPA values in the fertile range. Thirteen of the 17 DES-exposed male subjects, four of the 12 non-DES-exposed volunteers, and four of the 11 fertile control subjects demonstrated at least one abnormality of the reproductive organs.

Adolescent↗
PubMed1981

Disodium cromoglycate in dermatitis herpetiformis.

Eleven patients with dermatitis herpetiformis, all requiring dapsone to control their rash and taking a normal diet, were given disodium cromoglycate (DSCG) 1.5-1.6 g daily. Eight out of the eleven patients continued to take DSCG for periods varying from 6-11 months, the other three patients chose to discontinue the DSCG before 6 months. Of the eight patients taking DSCG for at least 6 months, none was able to stop taking dapsone. In three of the eight, the dapsone requirements were unaltered, whilst in two it decreased and in three it increased. The mean daily dose of dapsone was 105 mg/day before DSCG and 141 mg/day after DSCG. In the eight patients who took DSCG for at least 6 months, intestinal biopsies were performed before and after this drug. The macroscopic appearance was unchanged in four, improved in two and worse in two. The mean interepithelial lymphocyte count was 346 before and 342 after DSG.

Adult↗
PubMed1980

Comprehensive management of children on a paediatric ward: a family approach.

A team approach in the comprehensive management of children on a general paediatric ward is described. The team comprises paediatricians, nurses, a child psychiatrist, and a social worker, with a psychologist, play-leader, and teachers making important contributions. In this way members of the team learn from each other, and the paediatrician in training gains valuable experience about the management of children with emotional problems. The team approach is based on the principles of family therapy, but it also uses other forms of therapy--such as behavioural, marital, and individual. Children with severe psychosomatic problems in particular can be helped by such treatment, but other emotional problems are also suitable for management using such an approach.

Child↗
PubMed1980

Left lateral decubitus sonography of gallstones in the contracted gallbladder.

A prospective study of the accuracy in diagnosing gallstones using ultrasonography in the absence of a fluid-filled gallbladder was done over a 20 month period; 91 patients were studied. A focal echo complex with acoustic shadowing was shown to be a highly reliable criterion for diagnosing gallstones in a contracted gallbladder when (1) it was demonstrated on longitudinal, transverse, and left lateral decubitus views, and (2) the configuration of the echo complex remained the same.

Child↗
PubMed1979

A comparison of amphotericin B alone and combined with flucytosine in the treatment of cryptoccal meningitis.

We compared amphotericin B therapy for cryptococcal meningitis with a newer regimen containing both amphotericin B and flucytosine. In 50 patients with 51 courses of therapy adherent to the protocol, 27 courses were with amphotericin B and 24 with the combination. Even though the combination regimen was given for only six weeks and amphotericin B for 10 weeks, the combination cured or improved more patients (16 vs 11), produced fewer failures or relapses (three vs. 11), more rapid sterilization of the cerebrospinal fluid (P less than 0.001) and less nephrotoxicity (P less than 0.05) than did amphotericin B alone. The number of deaths was the same (five) with each regimen. Adverse reactions to flucytosine occurred in 11 of 34 patients but were not life threatening. We conclude that combined flucytosine-amphoericin B therapy is the regimen of choice in cryptococcal meningitis.

Adolescent↗