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Biomedical subjects

J I Watson

Publications and source records attributed to J I Watson.

At least 19 recordsLinked to original sources
PubMed1984

Effect of exercise on repolarisation abnormalities in patients with asymptomatic QT prolongation.

Patients with congenital QT prolongation have an increased incidence of ventricular arrhythmias and sudden death. Altered sympathetic tone has been suggested as an important contributing factor in this syndrome. Although some patients with an increased QT interval and arrhythmias have an abnormal QT response during exercise, the effect of exercise has not been reported in patients with acquired QT prolongation without clinical manifestations. The purpose of this study was to determine the pattern of QT change with exercise in patients with QT prolongation without exercise-induced arrhythmias in order to: 1) determine the most frequent response in this group; 2) observe the effect of posture on QT changes; and 3) compare the rate of QT change with a control group. Treadmill exercise testing was performed in 10 patients (mean age 52.1 +/- 8.0 years) with a QTc greater than 0.44 s; the results were compared with 14 patients with a normal QTc (mean age 45.8 +/- 12.1 years). Patients with an increased QT interval at rest experienced a significant reduction in QT interval during exercise (0.315 +/- 0.030 s vs 0.394 +/- 0.046 s standing at rest; P less than 0.01), as cycle length was decreased from 0.732 +/- 0.175 s to 0.489 +/- 0.062 s. Patients in the control group had a similar change in QT interval (0.297 +/- 0.015 s vs 0.359 +/- 0.029 s standing at rest (P less than 0.01), with a comparable change in cycle length 0.733 +/- 0.097 s vs 0.511 +/- 0.059 s.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1981

Studies on hybridization between a Barbary ram (Ammotragus lervia) and domestic ewes (Ovis aries) and nanny goats (Capra hircus).

Six nanny goats and 9 ewes were inseminated with Barbary semen and 4-5 days after insemination 16 hybrid embryos were recovered: 14 were transferred to ewes or nanny goats. Survival of embryos was monitored by return to service after transfer, peripheral plasma progesterone values and by examination at laparotomy. None of the Barbary ram x ewe embryos transferred to 4 ewes and 4 nanny goats or the Barbary ram x nanny goat embryos transferred to ewes survived. Of the 4 nanny goat recipients of Barbary rm x nanny goat embryos one had a resorbed fetus at 7 weeks after transfer, one was pregnant at 7 weeks but failed to produce a young and a third produced a healthy male 155 days after the transfer oestrus. The karyotype of the hybrid was 2n = 59XY, characterized by a single metacentric chromosome.

Animals↗
PubMed1980

An autosomal centric fusion translocation in the Red Poll breed in Australia.

The karyotype 2n = 59,XY,t:1/29 was found in two pure bred Red Poll bulls originating from stock imported from Britain. Orthodox stained and G-banded karyotypes of the condition in this breed are presented for the first time. Non-return rates for one bull suggest no impairment of fertility when selected for artificial insemination. However, in a related herd infertility has become a serious problem. It is suggested that selection pressure does not operate to eliminate the translocation and that caution should be exercised in the use of animals.

Animals↗
PubMed1978

The binding of anti-DNA antibodies as measured fluorometrically by ethidium bromide.

The phenanthridine dye ethidium bromide (EB) intercalates with double-stranded DNA (dsDNA) resulting in an enhancement of fluorescence. Single-stranded DNA (ssDNA) does not show this fluorescent enhancement. Purified IgG from patients with Systemic Lupus Erythematosus (SLE) containing anti-dsDNA antibodies competes with EB for binding to DNA resulting in a decrease in fluorescence. This study has shown that antibodies which bind ssDNA in the Millipore filter radioimmunoassay displace EB from dsDNA showing that antigenic determinants are available for binding in the double-stranded molecule. This study introduces the EB assay and presents a comparison with the Millipore filter assay.

Antibodies, Antinuclear↗
PubMed1976

A comparison of methods of screening for sperm antibodies in the serum of women with otherwise unexplained infertility.

Sera from 102 women with infertility due to a variety of causes and from 40 pregnant women were studied for the presence of antisperm factors. Three techniques were used: sperm microagglutination, sperm immobilization, and an indirect immunofluorescent technique for detection of sperm-bound immuno-globulins. There was no correlation between the results obtained using these three different techniques. Of the three, only the results of sperm immobilization tests correlated with primary unexplained infertility. The sperm microagglutination test appeared to measure nonspecific factors. Methanol fixation of spermatozoa used in the indirect immunofluorescent technique apparently resulted in nonspecific binding of immunoglobulins. When fresh spermatozoa were used no binding of immunoglobulin to spermatozoa could be demonstrated. The nature and location of the antigen(s) involved remain to be determined.

Antibodies↗