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Biomedical subjects

J G Hall

Publications and source records attributed to J G Hall.

At least 271 records · Page 15Linked to original sources
PubMed1980

Prenatal genetic diagnosis and elective abortion in women over 35: utilization and relative impact on the birth prevalence of Down syndrome in Washington State.

We have examined the relative contributions of a population-based antenatal detection program and unrestricted elective abortion used by women 35 years old and over in Washington State and King County for 1976--1977 to the declining birth prevalence of Down syndrome (DS). The amniocentesis/live birth (LB) ratio for women 35 years old and over was 20.5/100 LBs for King County and 11.7/100 LBs for Washington State in 1977. For the state in 1976, abortion ratios/1,000 LBs were 571 for women 35 to 39 years old and 1,096 for women 40 years old and over. Based on the total Washington State data, elective abortion has a greater impact on averting DS births than does the antenatal detection program. The impact of elective abortion appears to be related to its disproportionate use by women 35 years old and over compared to their contribution to the population of of LBs.

Abortion, Legal↗
PubMed1980

Significance of phenotypic and chromosomal abnormalities in X-linked mental retardation (Martin-Bell or Renpenning syndrome).

With the exception of macro-orchidism, three families with X-linked mental retardation showed diagnostic concordance of clinical features among the affected males. Since macro-orchidism was a variable feature among the otherwise identically affected males in one family, we question the existence of a separate entity of X-linked mental retardation characterized only be testicular enlargement. The X chromosome marker of Lubs was expressed, under the culture conditions of Sutherland, in lymphocytes of the affected males of two families, one with and the other without megalotestes. Two affected members of the third family, with megalotestes, did not show the marker. Telomeric structural changes similar to the mar(X) (qter) formation were found on certain autosomes, notably, chromosome 6 in some of the affected males, potential and obligate carrier females, and in both related and unrelated normal males. These autosomal markers appear to represent a nonspecific response to either in vivo or in vitro folate deficiency. Caution against premature introduction of this test for prenatal diagnosis, in the face of current ignorance regarding diagnostic specificity, is urged.

Female↗
PubMed1980

Lower limb anomalies in the thrombocytopenia absent-radius (TAR) syndrome.

We report a case of the TAR syndrome with severe abnormalities of the lower limbs. The syndrome of thrombocytopenia and radial deformities occasionally presents diagnostic difficulties when severe limb anomalies are present. Based on this case and 2 additional cases from the literature, reduction anomalies of the lower limbs should be considered part of the TAR syndrome.

Female↗
PubMed1980

Maternal and fetal sequelae of anticoagulation during pregnancy.

Review of published cases of pregnancies in which coumarin derivatives or heparin were administered demonstrates that use of either class of anticoagulant carries substantial risks. Of 418 reported pregnancies in which coumarin derivatives were used, one-sixth resulted in abnormal liveborn infants, one-sixth in abortion or stillbirth and, at most, two-thirds in apparently normal infants. In addition to the expected hemorrhagic complications, fetal effects of coumarin derivative administration include a specific embryopathy and central nervous system abnormalities. All available cases (including unpublished ones) of warfarin embryopathy and central nervous system abnormalities following gestational exposure to coumarin derivatives are reviewed, various complications are tabulated, critical periods of teratogenesis are discussed and possible mechanisms proposed. The use of heparin during gestation does not result in a significantly better outcome of pregnancy. In 135 published cases, the infants in one-eighth were stillborn, in one-fifth premature (a third of whom died) and, again at most, in two-thirds apparently normal. Because of the substantial risks of both clases of anticoagulants, and the inherent risks of pregnancy complicated by the indications for anticoagulation, prevention of pregnancy is usually indicated. If pregnancy occurs, a relatively normal outcome can be anticipated in about two-thirds of the pregnancies regardless of the anticoagulant used. Heparin does not appear to be a clearly superior alternative to coumarin derivatives.

Abnormalities, Drug-Induced↗
PubMed1980

Studies of the transport of polyclonal IgA antibody from blood to bile in rats.

Bile or thoracic duct lymph, collected from rats 7-9 days after suspensions of B. abortus, S. typhi or SRBC had been injected into the Peyer's patches, contained high titres of specific agglutinins. Samples of these fluids were injected i.v. into unimmunized, syngeneic recipients and the partitioning between blood and bile of the injected antibodies was studied and found to depend on the source and class of the antibody. IgA antibodies from lymph plasma disappeared rapidly from the recipients' blood and half of the dose was recovered in the bile within 2 h of its injection. IgA antibodies which had been collected from bile and so had previously traversed the liver and acquired secretory component, appeared in the recipients' bile much less rapidly so that less than half of the dose entered the bile over a period of 40 h. Passively administered IgG antibodies did not enter the recipients' bile to any significant extent and specific haemolysins never appeared in the bile after either passive or active immunization.

Agglutinins↗
PubMed1980

Studies of efferent lymph cells from nodes stimulated with oxazolone.

Efferent lymph from nodes regional to areas of skin that had been treated with solutions of oxazolone in acetone was collected from unanaesthetized sheep. The application of 5% solutions of oxazolone to unsensitized sheep caused no signs of acute inflammation or 'shut-down' of lymphocyte traffic; none the less, normal immune responses ensued so that immunoblasts, some containing immunoglobulin, were discharged into the lymph together with specific humoral antibodies. When previously sensitized sheep were challenged with 2.5% solutions of oxazolone the vigorous secondary responses were heralded by Arthus reactions, induced presumably by pre-existing antibodies, which were mainly of the IgG class. A similar sequence of events occurred in a thymus-deprived sheep which had undergone intra-uterine thymectomy at 60 days of gestation. Repeated applications of oxazolone to normal sheep did not exhaust or inhibit the characteristic changes in the flow and composition of the lymph. When immunoblasts from efferent lymph were radiolabeled with 125I-UdR and returned intravenously to the sheep they showed no significant tendency to localize either specifically or non-specifically in areas of skin that had been treated with contact-sensitizing chemicals.

Animals↗
PubMed1980

Comparative aspects of the transport of immunoglobulin A from blood to bile.

Polymeric and monomeric human IgA were isolated from the sera of patients with IgA myeloma; rat IgA polymer, monomer and IgG2 were isolated from the ascitic fluid or sera of Lou/Wsl rats bearing appropriate myelomata. The purified Ig preparations were labelled with 125I and injected intravenously into rats, rabbits, guinea-pigs or sheep that had had a cannula inserted into the common bile duct so that their bile could be collected quantitatively. Rats and rabbits transported 30% of the injected dose of both IgA polymers, but no other type of immunoglobulin, from blood to bile within 5--7 h. Sheep and guinea-pigs were unable to transport any of the immunoglobulin preparations from blood to bile, even though the injected material remained circulating in the blood.

Animals↗
PubMed1979

Warfarin embryopathy.

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Abnormalities, Drug-Induced↗
PubMed1979

Posterolateral (Bochdalek's) diaphragmatic hernia in sisters.

Two siblings with identical left posterolateral diaphragmatic (Bochdalek's) hernias are described. To our knowledge, there is one earlier description of siblings in which the diaphragmatic defects have been defined as posterolateral. The observation of these two families with a defect that is usually sporadic raises the possibility of etiologic heterogeneity among posterolateral defects of the diaphragm. Although overall recurrence risk is probably small, prenatal diagnosis by ultrasound should be possible and may improve perinatal management in familial cases.

Female↗
PubMed1979

The Summitt syndrome: observations on a third case.

A 6 1/2 year old male presented with acrocephaly, brachydactyly, clinodactyly, mild syndactyly of the hands and feet, genu valgum, and marked obesity. Roentgenograms of the hands revealed hypoplasia or aplasia of the middle phalanges. Roentgenograms of the feet revealed hypoplasia of the middle phalanges and deformity of the proximal phalangeal epiphyses of the great toes. Chromosomes studies revealed a normal 46,XY karyotype, and psychological testing revealed low normal intelligence. Current data support autosomal recessive inheritance, although X-linkage cannot be excluded.

Child↗
PubMed1979

Lack of effect by substance P at sites in the substantia gelatinosa where Met-enkephalin reduces the transmission of nociceptive impulses.

In alpha-chloralose anaesthetized spinal cats, Met-enkephalin amide (M-ENKA) and substance P were administered electrophoretically in the substantia gelatinosa while studying the excitation of deeper spinal neurones by noxious and non-noxious cutaneous stimuli. At sites where Met-enkephalin selectively reduced excitation by noxious skin stimuli, substance P was without effect. This result does not support the hypothesis that enkephalins are released at axo-axonic synapses on the terminals of substance P releasing primary afferent fibres.

Action Potentials↗
PubMed1979

Supraspinal inhibition of spinal neurones responding to nociceptive stimulation.

A study of the tonic descending inhibition present on neurones of laminase IV and V in the lumbar spinal cord of anaesthetized cats has been made employing reversible blocking of the spinal cord by cooling. The results suggest that neurones of both laminase are subject to a similar degree of inhibitory control and imply that they are equally important to the spinal transmission of noxious input.

Animals↗