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Biomedical subjects

J Walker

Publications and source records attributed to J Walker.

At least 469 records · Page 26Linked to original sources
PubMed1977

Effect of preoperative anaesthetic visit on anxiety.

Anxiety levels measured in patients who received preoperative reassurance about anaesthesia from a member of the hospital staff were significantly lower than those in a control group given no such support. Anxiety levels in patients who read a booklet designed to reassure about anaesthesia were less significantly reduced. Owing to the increasing work load in the operating theatre many anaesthetists can no longer afford the time to visit patients preoperatively. This study shows that either this trend should be reversed or the role of reassurer should be assumed by someone else, possibly the anaesthetic nurse. For optimal effect, the visits should be combined with use of the booklet. Unless such measures are taken, up to three million people each year may be being denied any form of reassurance before surgical treatment.

Adult↗
PubMed1977

Microinvasive squamous carcinoma of cervix in the Tayside region of Scotland.

A total of 117 patients with microinvasive squamous carcinoma of the cervix encountered between 1960 and 1972 is reviewed. No lymph node metastases were found in the 42 patients who had pelvic lymphadenectomy and only one died from her disease. The proposal is made that when the depth of invasion is 3 mm or less, microinvasive carcinoma can be treated in the same way as carcinoma in situ.

Adult↗
PubMed1976

A longitudinal study of parotid secretory kinematics by cinemicrography and computer analysis.

The kinematic responses of parotid gland acini to isoproterenol were studied in vitro by time-lapse cinemicrography. It was shown that once secretion begins, granule depletion accelerates to a maximum rate in 8-10 min, continues at a steady rate for 5-8 min and then slows, depletion becoming essentially complete 25-30 min after stimulation. The continuum of morphologic change manifested by the acinar lumen during secretion was quantified by computer analysis of sequential cine-frames representing a time resolution of 0.1 min. Interpretation of seventh-order and eleventh-order polynominal non-linear least squares trend curves shows that the lumen enlarges from an initial cross-sectional area of approximately 96 mum2 at 14.9 min. The shape of these curves suggests that after an initial partial enlargement the lumen shrinks (or remains steady) before climbing to the maximum. The basic pattern resembles distortion curves characteristic of two-phase viscoelastic compliance systems. It is also shown that luminal plasma membranes undergo a very active ebb and flow during the egestive phase of secretion.

Animals↗
PubMed1976

Homoserine kinase from Escherichia coli K12.

Homoserine kinase was purified to apparent homogeneity from a derepressed strain of Escherichia coli K12, using standard fractionation techniques. It is a dimer (Mr = 60000) composed of apparently identical polypeptide chains (Mr = 29000). Its amino acid composition and N-terminal sequence have been determined. L-Threonine is a competitive inhibitor of the substrate L-homoserine; this inhibition is straighforward and shows no sign of co-operativity. Evidence is presented that homoserine and threonine bind to the same site of this non-allosteric enzyme. The binding of homoserine and threonine can also be studied by difference spectroscopy; the latter studies reveal an unexpected effect of magnesium ions, which might be the basis for the unusual high Mg2+ requirement for optimal enzyme reaction.

Amino Acid Sequence↗
PubMed1976

Prognostic value of antenatal screening.

Rates of stillbirths and first-week deaths have fallen steadily in Scotland in the last 30 years. Seventy-five per cent of all such deaths in the City of Dundee now follow the clinical condition of "antepartum hemorrhage," "premature labor," "poor fetal growth," and "lethal deformity," all of which are conditions associated with poorer environmental conditions which are worse in larger industrial cities. Therefore, we are concerned with these clinical situations and with fetal death and subsequent morbidity of children born in those situations. This paper describes in summary a planned study of antenatal screening with assessment of fetal placental hormones, fetal biparietal diameter, and other determinants of fetal well-being, the growth of the child and weight at birth, the quality of the labor, the neonatal state, and the ultimate quality of the child.

Amniotic Fluid↗
PubMed1976

Effects of marijuana extract and tetrahydrocannabinol on electroencephalographic sleep patterns.

Marijuana extract, given in daily doses containing 70 to 210 mg delta-9-tetrahydrocannabinol (THC), induced effects on sleep that were virtually identical to those produced by the same doses of relatively pure (96%) THC. Both drugs reduced eye movements density with some tolerance developing to this effect. Stage 4 tendend to increase with drug administration. Abrupt withdrawal led to extremely high densities of eye movement, increased rapid eye movement (REM) durations, and a sharp but transient fall in stage 4 to baseline levels. These effects may be useful in the elucidation of the pharmacology of sleep. The effects on sleep of THC administration (but not withdrawal) closely resemble those induced by lithium. For this reason, we suggest further studies of THC in affective disorders. Evidence available thus far suggests that THC produces dysphoric symptoms in unipolar but not in bipolar depressed patients; these differences in response may prove of diagnostic value. An adequate therapeutic trial of THC in bipolar depressed patients has not yet been carried out.

Administration, Oral↗
PubMed1976

Preoperative risk factors and aorta-coronary bypass graft patency.

The relationship between graft patency and the presence of presurgical prognostic factors was studied in 636 patients who have undergone aorta-coronary bypass operation. We have found a positive correlation between vein graft patency and both coronary artery constriction score (p less than 0.01) and diastolic blood pressure (p less than 0.05). In patients studied up to one year after surgery, high graft patency was associated with both higher diastolic pressures (p less than 0.03) and higher cholesterol levels (p less than 0.001). However, high cholesterol levels also were associated with coronary arterial obstruction. In patients studied more than a year after operation, high constriction scores before the operation were associated with improved graft patency (p less than 0.03). Our findings indicate that short-term prognosis of the grafts is related mainly to hemodynamic variables.

Age Factors↗
PubMed1976

Perineal wound healing after abdominoperineal resection.

The healing of the perineal wound after proctectomy depends on the disease, the presence of perianal infection, and the technique of management of the perineum. Experience shows that when the perineum is left open, healing by secondary intention is accompanied by a significant morbidity, extended hospitalization, continued disability, prolonged postoperative drainage and an occasional persistent perineal sinus. The patients required daily care of the perineum for two to 12 months. The wound healed slower in patients with inflammatory disease of the colon. Within six months the perineum healed in 58 per cent of the patients with inflammatory disease and 70 per cent of the patients with carcinoma. After one year, healing had taken place in 98 per cent of the patients. It is necessary to leave the perineal wound open in the patients with perineal sepsis, contamination and uncontrollable hemorrhage. For the other patients, there should be some attempt to close the perineum and obtain primary healing of the wound.

Adult↗
PubMed1975

Isolation of tumor-specific antibodies from effusions of ovarian carcinomas.

Peritoneal effusions of patients with ovarian cancer contain sizable amounts of free and complexed immunoglobulins. By means of salt precipitation procedures, antibodies were recovered that after purification and concentration displayed a high degree of specificity against ovarian carcinoma cells. In indirect immunofluorescence, immunoglobulins recovered from seven different peritoneal effusions showed bright cytoplasmic staining with tissue cultures and fresh suspensions of ovarian carcinoma cells but not of normal ovaries or non-ovarian tumors. Immunoglobulins isolated from fluids of benign ovarian cysts or from effusions of non-ovarian tumors were negative in immunofluorescence tests. Autologous antibodies recovered from peritoneal effusions will be hopefully utilized in sensitive radioimmunoassay tests that are greatly needed for the early detection of ovarian cancer, the leading cause of death from gynecologic neoplasia.

Antibodies, Neoplasm↗
PubMed1975

Biological aspects of twin pregnancy in Dundee.

A review is presented of 712 twin pregnancies which occurred in Dundee between 1956 and 1971. It shows a falling age of twin reproduction, a changing ratio of mono- to dizygosity and the poor growth rates of both types. Birth weight variations suggest that "crowding" in the uterus may affect the individual growth of each twin, but the combined weight of twins continues to increase to term and shows no obvious sign of restriction.

Birth Weight↗
PubMed1975

The effects of adenosine triphosphate and adenosine diphosphate on transmission at the rat and frog neuromuscular junctions.

1 The effects of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) were investigated on evoked end-plate potentials (e.p.ps) and on miniature end-plate potentials (min. e.p.ps) recorded from muscle fibres of the rat diaphragm and the frog sartorius.2 ATP and ADP decreased the quantum content of the e.p.ps and the frequency of the min. e.p.ps. The maximum effects produced by the two substances were similar.3 The potency of ATP was found to be similar to that of adenosine. In the presence of adenosine, in a concentration producing its maximum effect, the addition of ATP had no further effect. This is compatible with the idea that ATP acts in the same way as adenosine.

Adenosine↗