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Biomedical subjects

B Harris

Publications and source records attributed to B Harris.

At least 127 records · Page 7Linked to original sources

Salivary steroids and psychometric parameters in male marathon runners.

Testosterone and cortisol in male marathon runners (n = 11) were determined in saliva samples (n = 28) collected during the three rest days preceding a competitive marathon and in the samples collected at 08.00h on the race day. An Eysenck Personality Inventory was completed on the first rest day and psychological state was assessed on rest days and on the morning of the marathon by completion of visual analogue scales for anxiety, depression, hostility and libido at four times each day. Anxiety, depression and hostility were positively inter-correlated. Extraversion and depression were negatively correlated. At 08.00h on the day of the marathon, anxiety and hostility scores were significantly higher than those on rest days, but depression and libido scores were unchanged. No relationship was found between depression or libido and any hormonal parameter. Race day cortisol correlated negatively with hostility, and changes in cortisol (09.00h) between the race day and the mean rest-day levels correlated with the corresponding changes in anxiety.

Adult↗

The hormonal environment of post-natal depression.

The incidence of post-natal depression is high, and dramatic changes in steroid hormones and prolactin occur in the post-partum period. In an attempt to correlate these events, 147 mothers, six to eight weeks after delivery of a healthy infant, completed standard psychological tests, including the Edinburgh, Montgomery-Asberg, and Raskin scales. They also provided matched samples of plasma for assay of cortisol, oestradiol, progesterone and prolactin, and saliva for assay of cortisol and progesterone. All steroid concentrations were within the appropriate normal ranges. Of the mothers, 14.9% were depressed on all three scales. Significant correlations were seen between depression ratings and salivary progesterone and prolactin. In bottle-feeders, salivary progesterone was positively associated with depression, whereas in breast-feeders it was negatively associated. Plasma prolactin levels were inappropriately low in depressed breast-feeders. These data indicate that differing therapies may be appropriate for depression in breast- and bottle-feeders.

Adolescent↗

The use of rating scales to identify post-natal depression.

One hundred and forty-seven mothers were screened for major depression at six to eight weeks post-partum. Using predetermined cut-off points, the Edinburgh Postnatal Depression Scale and the Beck scale were compared in their abilities to identify the 15% of subjects who had major depression according to DSM-III criteria. The sensitivity of Edinburgh scale was 95% and its specificity 93%. The performance of the Beck scale was markedly inferior, with a sensitivity of 68% and specificity of 88%.

Adult↗

Anxiety and the dexamethasone suppression test monitored with saliva.

To assess the effect of anxiety on response to the Dexamethasone Suppression Test (DST), cortisol concentrations were determined in patients who had various diagnoses, with anxiety as a secondary characteristic. Saliva was collected before and after venepuncture at 4:05 PM following completion of the Leeds Questionnaire at 3:00 PM. Matrix effects, which caused an initial artefactual decrease in cortisol levels in some saliva samples in patients with high anxiety, could be eliminated by repeated freezing/thawing. There was no significant difference between salivary cortisol concentrations before and after venepuncture, indicating that variability in response to the DST is not a correlate of anxiety and stressful venepuncture. There was no association between anxiety scores and plasma or salivary cortisol values: thus, anxiety is unlikely to be a major contributory cause of nonsuppression of hypercortisolemia in the DST.

Adult↗

Peripheral serotoninergic receptor sensitivity in senile dementia of the Alzheimer type.

Platelet aggregation induced by 5-hydroxytryptamine (5-HT) was used as a measure of the functional responsiveness of peripheral 5-HT receptors in controls and drug-free patients suffering from senile dementia of Alzheimer type (SDAT). No significantly different aggregatory response (5-HT/ADP ratio) was noted between the two groups of subjects. If the receptor mediating this response is a 5-HT2 receptor, there is no evidence to suggest that the functional activity of this system is abnormal in SDAT.

Aged↗

Regional distribution of the expression of a human stimulatory GTP-binding protein alpha-subunit in the human brain studied by in situ hybridization.

Using a cDNA probe complementary to an mRNA coding for the alpha-subunit of a human GTP-binding protein that stimulates adenylate cyclase we have studied its regional distribution in human brain by in situ hybridization histochemistry. The specificity of the hybridization signal was examined by using a labelled sense probe and RNase treatment. Gs alpha transcripts presented a widespread but heterogeneous distribution in human brain postmortem tissues. The cell bodies of the granular layer of the cerebellum were the most heavily labelled cells in all the cases examined. High levels of hybridization were also seen in the pyramidal cell layer of the hippocampus and over the cell bodies of the granule cells of the dentate gyrus. Several cortical regions also presented high levels of hybridization. Another area rich in the Gs alpha mRNA was the hypothalamus. The caudate and putamen nuclei presented intermediate levels while the globus pallidus, the thalamus, the midbrain and the brainstem presented only very low levels of hybridization. This distribution differs from the known distribution of adenylate cyclase activity and other GTP-binding proteins, and could indicate that this particular Gs alpha clone codes for a subset of the alpha-subunit of the Gs protein family.

Adenylyl Cyclases↗

Effect of nicotinamide on methionine metabolism in rat liver.

To test the response to increased utilization of methyl groups, we administered large dosages of nicotinamide to rats fed an adequate diet that contained limited amounts of methionine and choline. During the 4 d after the injection, we observed several significant effects on the hepatic concentrations of the enzymes and metabolites of methionine metabolism. Methionine and S-adenosylmethionine remained at control levels; the concentrations of S-adenosylhomocysteine exceeded the control values from 4 to 16 h; and the levels of serine and betaine were lower after 16 h. Treatment with nicotinamide resulted in higher hepatic levels of methionine adenosyltransferase (after 4 h) and cystathionine synthase (after 16 h). These data indicate that increases in both homocysteine methylation and S-adenosylmethionine synthesis may be components of the response to excessive methyl group consumption. An increased synthesis of cystathionine would provide for the removal of S-adenosylhomocysteine (and homocysteine) derived from the adenosylmethionine-dependent methylation of nicotinamide.

Animals↗

Neuroendocrine (Merkel cell) carcinoma of the skin. Its natural history, diagnosis, and treatment.

Over 400 cases of neuroendocrine (Merkel cell) carcinoma of the skin (NCS) have been reported. This tumor continues to pose problems in diagnosis and effective treatment for physicians unfamiliar with its biological characteristics. Reported here are five additional cases of NCS and the literature for this rare neoplasm is comprehensively reviewed. An early and accurate diagnosis is made possible by combining clinical presentation with results of histologic study, immunoperoxidase staining for neuron-specific enolase (NSE), epithelial membrane antigen (EMA), cytokeratins, and electron microscopy. NCS is an aggressive tumor. Depending on the length of follow-up, up to 40% of tumors locally recur, 55% develop regional nodal metastases, and 36% undergo distant metastasis. Survival is sex, but not age, dependent, with an overall 2-year survival rate of 72% (males 58% vs. females 79%). No standard procedure for initial and/or follow-up treatment for NCS exists. The authors recommend that NCS be treated, whenever possible, using the same rationale as applied for the treatment of squamous cell carcinoma of the skin.

Adenocarcinoma↗

Performance of the dexamethasone suppression test in depressive illness according to ICD and DSM-III classification systems.

The performance of the dexamethasone suppression test was assessed in 90 consecutive admissions with a diagnosis of depression, categorised according to two classification systems (DSM-III and ICD-9). Non-suppression was found in most of the diagnostic categories, but there was a highly significant association with the DSM-III classification 'major depressive episode with melancholia' (52%) in comparison with the ICD group 'manic-depressive illness-depressed' (29%).

Adolescent↗

Effects of citrus molasses distillers solubles and molasses on rumen parameters and lactation.

Effects of dietary citrus molasses distillers solubles (0, 6, 12, and 18% of DM) on diet digestibility and ruminal parameters were studied with four fistulated Holstein cows fed each diet in Latin square sequence. Diets were 25% cottonseed hulls with solubles substituted for corn. Dry matter and organic matter digestibilities were increased curvilinearly with peak at 6%. Crude protein digestibility was depressed linearly and ADF curvilinearly with added solubles. Ruminal acetic acid proportion increased linearly and propionic acid decreased curvilinearly. Change in butyric acid was small with 0, 6, and 12% solubles but it increased dramatically with 18%. In a 36-cow (107 cow-period) lactation experiment with corn silage-based and cottonseed hull-based diets (0, 3, 6, and 9% solubles) milk yield increased; the diet containing 6% solubles gave highest production. We compared cane molasses (3 and 6%), liquid hemicellulose extract (3%, Masonex), and liquid lignin sulfonate (3%, Flambeau) added to cottonseed hull diets. Linear increases in milk yield and FCM were obtained with cane molasses; Flambeau and Masonex effects on production were not different from control. With diets and amounts used in these experiments, citrus molasses solubles and cane molasses each at up to 6% of DM nutritionally were superior to corn.

Animal Feed↗

Comparison of different methods of expressing dietary protein for lactating dairy cows.

Data were from Holstein cows from 20 experiments at the University of Florida (1688 cow-period observations). Objectives were to compare milk responses to increasing dietary percent or daily intake of CP, estimated undegradable CP, and estimated metabolizable protein from Burroughs and Chalupa equations and to determine if higher producing cows (26.8 kg milk/d) responded differently to increasing dietary protein percent or intake than do lower producing cows (18.9 kg milk/d). The mathematical model included experiment, cow-within-experiment, period, body weight, and source of roughage. Intake of protein (kg/d) had a greater effect (cubic polynomial) on milk yield than protein percent of DM since CP, undegraded protein, Chalupa metabolizable protein, and Burroughs metabolizable protein intakes explained 17.2, 20.9, 23.5, and 24.1% of residual variation in milk yield compared with .6, 2.1, 1.7, and 2.1%, for percents of DM. High producing cows responded more to increasing protein intake than did low producing cows. Respective protein intake variables explained 20.6, 23.7, 30.5, and 31.2% of residual variation in milk yield in high production group compared with 17.2, 23.1, 20.6, and 20.6% in low production group.

Animals↗

Quality assurance in residences for people with a disability.

OBJECTIVE: To review the quality of service in 7 residences for people with a disability administered by the NSW Department of Health in the New England Region. METHOD: Evaluation of each residence by an evaluation team using an evaluation package incorporating three approaches to assessment: process measures, goal-oriented outcome measures, and interviews or questionnaires. RESULTS: This comprehensive review of the 7 residences showed that high standards had been set throughout the New England Region and that the evaluation package was a powerful tool for staff keen to improve the lifestyle of people with a disability. Some of the notable changes made as a direct result of the evaluation included additional staff for recreation and leisure; more flexible administrative control from local hospitals; increased staff consistency in home routine training; and increased community integration programming.

Persons with Disabilities↗

Thyroid status in senile dementia of the Alzheimer type (SDAT).

Thyroid function was investigated in a group of 21 patients with severe senile dementia of the Alzheimer type (SDAT) and in a group of 17 age and sex matched normal controls. Free thyroid hormone levels (triiodothyronine (T3) and thyroxine (T4) were measured, as were also the thyrotrophin (TSH), prolactin (PRL) and growth hormone (GH) responses to thyrotrophin releasing hormone (TRH)). When compared to controls, patients demonstrated a significantly lower free T3 value (but not free T4), a blunted TSH response to TRH, slightly elevated basal PRL and GH values and a small GH response to TRH. However, all differences were small in biological terms and were within the laboratory's normal range. This emphasizes the relative normality of neuroendocrine function, particularly thyroid status, in SDAT.

Aged↗

Salivary cortisol for monitoring adrenal activity during marathon runs.

In non-elite male runners (n = 8), changes in adrenal activity were monitored by measurement of salivary cortisol in samples collected at 4-mile intervals during marathon runs. These changes were compared with those in similarly timed samples collected on rest days. Immediately prior to the Cardiff marathon, at 09.00 h, mean salivary cortisol concentrations (21.5 nmol/l) were higher than those in similarly timed rest day samples (14.9 nmol/l). Cortisol concentrations increased during the marathon, and although values at 25 miles were high (79.4 nmol/l), maximum values (87.9 nmol/l) were observed in samples collected 30 min after completion of the run. Some Cardiff marathon runners also participated in the Bristol marathon (n = 4) and a non-competitive event (n = 3). The changing pattern in secretory activity was similar in all events. The easy collection of saliva without cessation of exercise is ideal for monitoring the hormonal response to exercise.

Adrenal Cortex↗