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Biomedical subjects

L Edwards

Publications and source records attributed to L Edwards.

At least 127 records · Page 7Linked to original sources
PubMed1985

Case report of prolactin and bipolar illness: a longitudinal study.

A longitudinal and naturalistic study of nine bipolar patients attending a lithium clinic during a six-month period was undertaken. Prolactin plasma levels and psychiatric symptoms were evaluated bi-weekly. Wide interindividual and intraindividual fluctuations were observed both in prolactin levels and psychiatric symptoms. The relationship between prolactin and affective episodes was found to be complex. In a few instances, sharp prolactin changes preceded behavioral modifications. Bipolar disorders, even if treated, appeared to be unstable conditions, from both the phenomenological and neuroendocrinological viewpoints.

Adult↗
PubMed1985

The use of a platelet nucleotide assay as a possible diagnostic test for malignant hyperthermia.

A bioassay, using high-performance liquid chromatography (HPLC) analysis of platelet adenosine nucleotides and hypoxanthine, was studied for its potential use as a test for MH susceptibility. A protocol for the assay was developed, based on the method outlined by Solomons and Masson. The HPLC procedure was a rapid, efficient, sensitive, and highly reproducible technique for measuring ATP, ADP, AMP, and hypoxanthine in platelets. Conditions of extraction and storage were critical for preventing degradation of the nucleotides. Extraction of nucleotides at icebath temperature was found necessary. Storage of platelet extract in PCA, even at -20 degrees C, showed loss of ATP and ADP; hence, neutralization with KOH was essential before storage. Contrary to the findings of Solomons et al., the present study demonstrated that neither ATP depletion nor per cent reduction in nucleotide ratios in platelets treated with halothane can be used as a definitive test for the diagnosis of MH susceptibility. The reason for this disagreement is unclear; however, differences in methods and altitude are implicated. It is possible that the platelet is not affected by malignant hyperthermia and thus cannot serve as a test system for the detection of the syndrome.

Adenine Nucleotides↗
PubMed1985

Indole amines and amino acids in various brain regions after infusion of branched chain amino acids into hepatectomized rats.

This study was designed to determine regional changes of amino acids and indole amines in the brain and possible interactions between amino acids and indole amines 18 h after hepatectomy in rats. Hepatectomy and glucose infusion alone resulted in a profound increase of most large neutral amino acids (LNAA) in plasma and in the brain except for the branched-chain amino acids (BCAA), which maintained normal or somewhat lower values in plasma. Hepatectomy and infusion of glucose combined with BCAA sharply reduced the plasma and brain amino acid concentrations of other LNAA. Simultaneously the concentrations of serotonin and 5-hydroxyindoleacetic acid were decreased in all brain regions. In both groups of hepatectomized rats there were regional variations of the amino acid and the indole amine concentrations in the brain, but the response to BCAA infusion was generally the same in all brain regions. No difference in survival between the 2 groups could be found.

Amino Acids↗
PubMed1983

Double-ended pigtail polyethylene stents in management of benign and malignant ureteric obstruction.

Surgical urinary diversion for incurable pelvic malignancy has a high morbidity and mortality, and external drainage provides less than ideal palliation. Six patients with ureteric obstruction caused by cancer have been managed by operative or endoscopic insertion of self-retaining polyethylene tubes. These techniques also have applications in non-malignant disease, and the treatment of two patients with benign ureteric stricture is described.

Abdominal Neoplasms↗
PubMed1982

Effect of infusing the branched-chain amino acids on concentrations of amino acids in plasma and brain and on brain catecholamines after total hepatectomy in the rat.

In totally hepatectomized rats supported by infusion of glucose, the concentrations of many amino acids in plasma and brain rose progressively over time, while the brain levels of norepinephrine decreased. Infusion of a solution containing glucose, leucine, isoleucine, and valine after hepatectomy greatly reduced the accumulation of other essential amino acids in plasma and brain. However, the decrease in brain norepinephrine content was not significantly affected by this infusion, suggesting that high brain concentrations of monoamine precursor amino acids are not the primary cause of norepinephrine depletion after hepatectomy.

Amino Acids↗
PubMed1982

An objective comparison of transurethral resection and bladder neck incision in the treatment of prostatic hypertrophy.

Transurethral resection has become the operation of choice in almost all cases of benign prostatic enlargement. However, when the gland does not exceed 30 gm. bladder neck incision is easier to perform, results in a lower morbidity, and is less likely to be followed by incontinence and retrograde ejaculation. We studied 2 groups of men with proved obstruction. Complete urodynamic investigation was done on 51 patients before and on 44 patients after the operation. We compared our subjective and objective findings in the 2 groups. The conclusion suggest that bladder neck incision is as effective as transurethral resection in relieving the obstruction of prostatic enlargement in the presence of a small gland.

Humans↗
PubMed1982

Plasma and skeletal muscle amino acids following severe burn injury in patients and experimental animals.

This study describes and analyzes sequential changes in plasma and skeletal muscle free amino acids following severe burn injury. Plasma free amino acids were determined in children (n = 9) with burns averaging 60% total body surface area and were compared with laboratory beagles (n = 44) which received a flame burn totaling 30% of their body surface area. In addition, needle biopsy specimens were obtained from the semitendonosus muscle in the animals to determine free intracellular amino acids. In both patients and animals the amount of total free amino acids in plasma fell following burn, suggesting relative protein deficiency. This drop was primarily due to a 47% drop in nonessential amino acids. However, plasma phenylalanine was consistently higher than normal following burn, and was strongly associated with death and weight loss in both animals and patients, especially when analyzed as a ratio with tyrosine. This finding suggested excessive catabolism, hepatic dysfunction, or both. Plasma levels of several amino acids correlated significantly with weight loss. Alterations in muscle free amino acids generally were similar to plasma amino acids. Exceptions were muscle alanine and glycine which strongly correlated with weight loss. However, the determination of muscle free amino acid profiles did not yield clinically useful information not available from plasma profiles. Plasma levels of liver enzymes suggested progressive hepatic dysfunction. These studies show that the laboratory beagle is a good model for studying the metabolic alterations of amino acids that accompany burn injury, since they mimic humans in many parameters which appear to be most useful with respect to clinical evaluation.

Amino Acids↗
PubMed1980

Clinical phase I-II and pharmacokinetic study of high-dose thymidine given by continuous intravenous infusion.

High-dose thymidine (dThd) was given to 12 patients with advanced hematological and solid tumors. The dose schedule used was 75 g/sq m/day, given i.v. continuously for 5 days or more. Myelosuppression, especially leukopenia, was the dose-limiting toxicity. Nonhematological toxicities affected the gastrointestinal tract (nausea, vomiting, anorexia, diarrhea, and indigestion) and the central nervous system (somnolence, headache, visual illusions, and memory impairment). Patients who had received cumulative doses of dThd developed alopecia. Thymine crystals were noted in the urine after refrigeration. Tumor regression (less than partial remission) occurred in one patient with melanoma. Three of four patients with acute leukemia had a fall in peripheral white blood cell counts and blasts but no marrow improvement. Four patients with adenocarcinoma (three colon, one unknown primary) had stable disease. Pharmacokinetic studies revealed that, at a dThd dose of 75 g/sq m/day, millimolar concentrations of dThd and thymine can be achieved in the plasma. The half-life of dThd was approximately 100 min. One-third of the plasma concentrations was measurable in the cerebrospinal fluid. dThd was mainly excreted by the kidneys.

Adolescent↗
PubMed1979

Interstitial cystitis.

Twenty histologically proven cases of interstitial cystitis were investigated in an attempt to find evidence of a possible autoimmune mechanism in its aetiology. HLA tissue typing was performed, autoantibody profiles were obtained, and a questionnaire of the patients' past history completed, especially with respect to other autoimmune conditions. An experiment was designed to test the effect of sodium cromoglycate on rat bladders. The results are discussed in relation to the management of patients with interstitial cystitis.

Aged↗