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Biomedical subjects

J E Davis

Publications and source records attributed to J E Davis.

At least 145 records · Page 8Linked to original sources
PubMed1978

Effects of beta-mercaptoethanol and chelating agents on the stability and activation of creatine kinase in serum.

We investigated the effects of sulfhydryl compounds on the stability of creatine kinase (CK) in unfrozen human serum and found that both beta-mercaptoethanol and N-acetylcysteine led to accelerated loss of the endogenous serum enzyme activity. This is in contrast to the results of others who have either studied the stability of exogenous enzyme added to human serum or studied endogenous enzyme in frozen serum. The addition of cation chelators to serum markedly improved the stability of the endogenous CK activity. The enhanced stability was independent of chelation of calcium, iron, manganese, copper, or zinc. In addition, cation chelators caused a 16% increase in the CK activity of fresh samples. This latter effect was independent of the activation of CK by BME and could be accounted for by chelation of calcium ions during the assay. The data suggest that addition of cation chelators prior to storage may be useful in enhancing the stability of CK in serum whereas sulfhydryl compounds should be added prior to assay rather than prior to storage.

Calcium↗
PubMed1978

Cutaneous metastases from prostatic carcinoma.

A case of prostatic adenocarcinoma associated with extensive cutaneous metastases and malignant acanthosis nigricans is reported. Pertinent literature is reviewed. The pathogenesis of the possible mechanism of the development of cutaneous metastases in this as well as other related cases is discussed.

Acanthosis Nigricans↗
PubMed1978

Fluorescent derivatives of prostaglandins and thromboxanes for liquid chromatography.

Fluorescent esters of the prostaglandins D2, E2, F2alpha, and 6-keto-F1alpha and of thromboxane B2 have been prepared using the reagent 4-bromomethyl-7-methoxycoumarin. All of these derivatives can be separated in a single run either by thin-layer or high-performance liquid chromatography (TLC or HPLC). As little as 20 ng of PGE2 can be detected after derivatization and HPLC analysis. Identification of thromboxane B2 produced by human platelets and of 6-keto-PG F1alpha produced by bovine aortic microsomes has been achieved with this method.

Animals↗
PubMed1978

Significant immunologic factors in male infertility.

A number of patients who suffer from involuntary infertility showed a sperm antibody in the blood serum as detected by 2 different methods of sperm agglutination. These techniques are the Kibrick method (gelatin agglutination test) and the F-D method (tube-slide agglutination test). With the former technique 9% of men and 18% of women from infertile couples had a positive result, while the latter technique revealed 5% of men and 15% of women with positive results. Such cases are termed immunological infertility. Several cases of necrospermia also showed sperm antibody activity. In vasectomized men it has been shown that 50 to 60% have sperm antibody during the first year postoperatively. To develop new methods for treatment of infertility immunosuppression by means of corticosteroid medication was applied. A 7-day regimen of 96 mg. per day methylprednisolone was studied. A drastic decrease of antibody level could be seen in some cases and the wives became pregnant. There has been approximately a 30% success rate in a group of 15 such couples.

Antibodies↗
PubMed1978

An evaluation of the Veterans Administration day hospital program.

A study of the day hospital program of the Veterans Administration was aimed at determining how well patients functioned three months after admission in relation to nine treatment goals, and how much they improved between admission and follow-up. The study group consisted of 1410 patients admitted to 34 VA day hospital programs; follow-up interviews were conducted with 70 per cent of them. At follow-up less than 10 per cent of the patients showed significant problems related to delusions, hallucinations, irrelevant speech, suicidal preoccupation, antisocial behavior, drinking, poor hygiene and eating habits, and assaultiveness. However, almost a fourth were significantly withdrawn, about a third were anxious, and three-fifths were not self-supporting. From the perspective of improvement during the three months, the study showed that treatment was helpful in all areas except promoting economic independence; it was most effective in reducing perceptual-cognitive dysfunctioning, emotional distress, and interpersonal difficulties.

Adult↗
PubMed1978

Hemoglobin A1c levels in a diabetes detection program.

Hemoglobin A1c concentration (HbA1c) was compared to the plasma glucose responses at 1 and 2 h of an oral glucose tolerance test (OGTT) in 63 subjects preselected because of postprandial hyperglycemia. HbA1c concentrations were correlated with 1- and 2-hour plasma glucose responses during the OGTT (r = 0.776 and 0.8602, respectively). The OGTT responses were diabetic-like in 21, indeterminate in 15, and normal in 27 subjects. HbA1c values were within normal limits in all subjects who had a normal or indeterminate OGTT response and in 10 out of 21 with a diabetic OGTT. The 2-h OGTT response among the 10 diabetic responders with normal HbA1c was 200 +/- 31 mg/100 ml (mean +/- SD), while that of the 11 diabetic responders with elevated HbA1c was 352 +/- 122 mg/100 ml. All subjects with an elevated HbA1c had a 2-h plasma glucose above 228 mg/100 ml, whereas only 7% of subjects with a normal HbA1c had a 2-h glucose above this value. It is concluded that only about half of the patients currently diagnosed as having mild or chemical diabetes by OGTT have elevated HbA1c and that an elevated HbA1c is usually associated with 2-h OGTT levels above 228 mg/100 mg.

Blood Glucose↗
PubMed1978

A high-performance liquid chromatography method for hemoglobin A1c.

Hemoglobin A1c (HbA1c) is a glycosylated derivative of hemoglobin and is one of a family of derivatives whose concentrations are elevated in patients with diabetes mellitus. Published methods for the measurement of HbA1c are relatively tedious and require modest amounts of blood. A high-performance liquid chromatographic (HPLC) method for the determination of HbA1c is presented. The method is rapid (20 minutes), precise (coefficient of variation of 5-10 per cent), uses small amounts of sample (3 microliter.), can be automated. A sample preparation technique using filtration was developed that shortened and simplified preparation of venous blood and allowed use of capillary samples. HbA1c was measured by this method in three age-stratified groups of controls and a group of insulin-requiring juvenile diabetics. There was clear separation of HbA1c values between all normals (5.9 +/- 1.3, 5.6 +/- 0.7, 7.1 +/- 0.9 per cent) and the diabetics (12.1 +/- 2.4 per cent). Use of this method can facilitate large-scale clinical investigations and permit biochemical investigations of the metabolism and formation of hemoglobin A1c where small sample sizes are necessary.

Adolescent↗
PubMed1977

Vasectomy: benefits versus risks.

The benefits and risks of modern vasectomy are presented, including a discussion of precautions and contraindications, the incidence of specific complications and suggestions for minimizing them, and the incidence of and reasons for procedure failures. Long-term side effects, including psychological sequelae, are also discussed.

Granuloma↗