Search PubMed⌕ Search

Biomedical subjects

M Hall

Publications and source records attributed to M Hall.

At least 271 records · Page 15Linked to original sources
PubMed1985

The utility and validity of daytime naps in the assessment of sleep-onset insomnia.

This study examined the discriminant validity, consistency, and reactivity of afternoon naps for assessing sleep-onset insomnia. Eleven insomniac and 17 noninsomniac subjects came to a sleep laboratory for three afternoon naps while multiple electrophysiological and subjective measures were taken. The results indicated that sleep-onset latencies during the afternoon naps significantly discriminated between insomniac and noninsomniac subjects. Further, significant correlations were found among most measures of sleep-onset latency measured both electrophysiologically and subjectively. The proportion of variance in sleep-onset latency accounted for by groups (insomniac vs. noninsomniac) increased over the three naps. Finally, a comparison of the results from this study with those from three all-night studies using identical facilities and procedures revealed that the sleep-onset latencies from this nap study were within the ranges expected on the basis of the all-night studies.

Adolescent↗
PubMed1985

Ureteral stenosis after kidney transplantation: true incidence and long-term followup after surgical correction.

Between March 1965 and December 31, 1982, 421 kidney transplantations were performed in our department. The over-all incidence of ureteral stenosis was 5.5 per cent. However, when the number of patients at risk at various times after transplantation was considered the probability for ureteral stenosis to develop was 4.6 per cent at 1 year, 7.7 per cent at 2 years and 9.7 per cent at 5 years. Preoperative and postoperative complications were frequent. The wound infection rate was 21.9 per cent and 2 of the 24 patients died of septic shock. Graft survival rate after definitive surgical correction of ureteral stenosis was 71 per cent at 1 and 2 years, and 65 per cent at 3 years. Late results justify the efforts to re-establish correct urinary drainage of the graft.

Follow-Up Studies↗
PubMed1985

Low glycemic index carbohydrate foods in the management of hyperlipidemia.

Reduction in the mean glycemic index (GI) of diets of 12 hyperlipidemic patients from 82 +/- 1 to 69 +/- 2 units (p less than 0.001) for a 1 mo period resulted in a significant reduction in total and LDL serum cholesterol and serum triglyceride by comparison with the mean lipid values for the preceding and following control months. The change in GI of the diet was achieved largely through manipulation of the cereal products and was not related to large differences in the amount of dietary fiber. In addition, apart from a small mean increase in unsaturated fat and calorie intake during the control periods, no difference was seen between the proportion of macronutrients on either treatment as determined by 1 wk diet histories recorded on alternate weeks throughout the 3 mo study. Selection of low glycemic index foods may therefore be a useful adjunct to the management of hyperlipidemia.

Adult↗
PubMed1985

Oncodevelopmental enzymes of the Dunning rat prostatic adenocarcinoma.

In this paper, data are presented which demonstrate that adenylate kinase and creatine kinase are oncodevelopmental enzymes in the rat prostate. The Dunning tumor (dorsal rat prostate) was used as a model system; four sublines of the tumor (R3327-H, R3327-AT, MAT Lu, and MAT LyLu) were studied. The tumor lines were maintained as solid tumors in syngeneic rats (Copenhagen) and as monolayers in tissue culture. The appearance of adenylate kinase with malignant transformation of the dorsal prostate was demonstrated. The disappearance of the CK-M subunit of creatine kinase and decreasing levels of creatine kinase were demonstrated with increasing anaplasia. The lactate dehydrogenase (LDH) concentration increased with increasing anaplasia, and the LDH isoenzyme pattern shifted to a more glycolytic pattern (LDH-4, LDH-5). The malignant isoenzyme pattern was reversible with the use of a differentiating agent (dimethyl sulfoxide). Prostates from neonatal rats and castrated adult male rats exhibited patterns of creatine kinase and adenylate kinase similar to those of the undifferentiated tumor. The oncofetal isoenzyme pattern of the castrated rat prostate was reversible with physiological levels of exogenous testosterone.

Adenocarcinoma↗
PubMed1985

Adenylate kinase: an oncodevelopmental marker in an animal model for human prostatic cancer.

Data are presented demonstrating that adenylate kinase (AK; EC 2.7.4.3) is an oncodevelopmental enzyme in the prostate of Copenhagen rats. We selected the Dunning tumor (dorsal rat prostate) as a model system because it most nearly approximates the human pathology. Four sublines of the tumor (R3327-H, R3327-AT, MAT Lu, and MAT LyLu) were studied. The tumor sublines were maintained as solid tumors in syngeneic rats and as monolayers in tissue culture. AK activity appeared in conjunction with malignant transformation of the dorsal prostate. We also determined the normal developmental enzyme pattern: AK was present in prostates of newborns, but was undetectable in prostates of adults. However, AK increased after castration. Therefore, we propose AK as a potential oncofetal tumor marker in prostatic cancer.

Adenocarcinoma↗
PubMed1984

Phenotypic basis for a feeding change in an insular population of garter snakes.

Predation on birds, an unusual behavior for the common garter snake (Thamnophis sirtalis), has been observed and documented in an insular garter snake population. Feeding preference tests were performed on naive neonatal snakes and experienced adults from both the island test population and a nearby mainland control population. No significant preference for birds as a prey item was found for either neonates or adults from either population. Therefore, neither a genetic nor an ontogenetic basis for the observed behavior was demonstrable. Birds tainted with a piscine odor, however, elicited a positive feeding response from adult snakes from both geographical sources. We propose that the observed behavior in the field is a result of learning to exploit an abundant, readily available resource already in the predator's repertoire.

Animals↗
PubMed1984

In vitro characterization of MAT LyLu: a Dunning rat prostate adenocarcinoma tumor subline.

Prostate carcinoma has been a therapeutic challenge. The Dunning tumor, a rat prostate adenocarcinoma tumor model, has been used to evaluate prostate carcinoma treatment protocols. The Dunning tumor subline, MAT LyLu , as described in this report, has been established and characterized as an in vitro continuous cell culture. The cell culture has been stable for greater than 60 passages. The in vitro characteristics of the MAT LyLu cell culture, such as growth rate, loss of contact inhibition, clonogenicity, morphology and tumorigenicity, are consistent with the malignant characteristics of the Dunning tumor subline. The MAT LyLu cell culture has enzyme activities which can be used to characterize the cell line. The establishment of MAT LyLu as a continuous cell culture should provide a controlled approach to evaluate the etiology and treatment of prostate carcinoma.

Adenocarcinoma↗
PubMed1984

Structural and functional impairment of adrenergic input to intraocular cerebellar grafts during thyroid hormone deficiency.

Embryonic cerebellae were transplanted to the anterior eye chamber of normal and thyroidectomized adult rats and were left in the eye to mature for 5 weeks. The cerebellar grafts received adrenergic innervation from the sympathetic ground plexus of the host iris. The density of adrenergic fibers innervating the grafts was reduced by approximately 50% in all thyroidectomized groups, without any effect on the fluorescence intensity or the morphology of individual nerve fibers. The reduction in adrenergic ingrowth was entirely prevented in grafts raised in similarly thyroidectomized recipients, which were substituted daily with thyroxine (100 micrograms/kg, SC). Electrophysiologically, there was no difference between the groups in terms of spontaneous firing rate of Purkinje neurons, recorded extracellularly from cerebellar grafts. However, there was a 10-fold decrease in the potency of catecholamines to inhibit the spontaneous neuronal activity in thyroidectomized hosts as compared to controls when applied either locally by micropressure ejection or by superfusion. Similar to the observed histologic changes in catecholamine innervation, the abnormal responsiveness of hypothyroid cerebellar neurons to locally applied catecholamines could be prevented by daily substitution with thyroxine in these animals. It is thus concluded that there is both structural and functional impairment of the adrenergic innervation of intraocular cerebellar grafts that underwent development under conditions of thyroid hormone deficiency.

Adrenergic Fibers↗
PubMed1983

Elbow arteriovenous fistula (EAVF) for chronic hemodialysis in small children.

Elbow arteriovenous fistulae (EAVF) were constructed in 10 children aged 27 mo to 10 yr. There were no operative failures. Follow-up ranged from 5 to 22 mo. Three episodes of thrombosis occurred in a single child. The fistula was recanalized each time. The creation of an EAVF is a simple surgical procedure. Children weighing as little as 10 kg were efficiently dialysed for prolonged periods of time with this vascular access device.

Arteriovenous Shunt, Surgical↗
PubMed1983

Leguminous seeds in the dietary management of hyperlipidemia.

Seven male hyperlipidemic patients substituted approximately 140g dried beans daily for other sources of starch in their diet over a 4-month period. After this, mean fasting serum triglyceride levels were reduced by 25 +/- 5% (p less than 0.01) while total serum cholesterol levels were 7 +/- 2% (p less than 0.5) lower than the values measured during the previous five clinic attendances (12 +/- 2.5 months). However, low- and high-density lipoprotein cholesterol levels remained unaltered. While taking beans a nonsignificant fall (0.7 kg) was seen in body weight. Nevertheless no change was seen in macronutrient intake determined by 1-wk diet histories recorded both before and four times during the study, although cholesterol intake decreased by 80 mg (p less than 0.02). Reintroduction of dried leguminous seeds into a Western diet may be a useful adjunct to the management of hyperlipidemia.

Adult↗
PubMed1983

Cell division in Deinococcus radiodurans and a method for displaying septa.

The study of sections, freeze-cleaved, and whole-cell preparations of Deinococcus radiodurans supported the contention that septa close assymmetrically and originate from discrete opposing locations on the cell surface. Tetrads and the larger associations (sheets) of cells in some strains were formed by alternate and synchronized divisions in two planes. The polarity initiating the second division in cells of the Sark strain, in particular, was often expressed in slower growing cells before completion of the first division so that the advancing margins of the first septum were diverted towards the nearest new pole; the resulting gap was closed later on, and consequently, the cell compartments of this coccus were in communication for some time after two rounds of nuclear segregation. Freeze cleaving showed that the initial generation of septa involved a short sulcus in the plasma membrane and not a circumferential infolding. The shape and form of the developing septum was inferred from sections but was displayed in whole-cell preparations by a technique which selectively and positively stained a septal component. Positive staining of the septum with uranyl salts was appreciable when the relative stainability of the peripheral wall (mainly peptidoglycan) was reduced by pretreatment with salts of low atomic weight metals (0.01-1.0%, w/v) such as cobalt, copper, iron, or zinc. Examination of these whole-cell preparations by stereoscopy showed that the septal diaphragm closes as a slit or long oval, and the advancing margin shows curvature towards the next axis of division. The mechanism and exact site of this positive staining was not elucidated; vancomycin blocking of the uncross-linked peptides of peptidoglycan was almost as effective as the transition metal salts as a foretreatment for staining septa.

Cell Division↗
PubMed1983

Localization of antibody binding sites in ultrathin sections of unembedded frog retinal tissue.

Much ultrastructural detail is retained in tissue fixed only with aldehydes and subsequently air-dried after suspension in a polyvinyl acetate emulsion. The latter provides an external support only, but permits ultrathin sectioning; thus, an exposure of intracellular contents for potential immunocytochemical reactions is achieved. Sections of unembedded frog retina so prepared have been studied with success. The tissue was incubated first with a rabbit antiserum prepared against gradient purified bovine rod outer segments. Following incubation, reacted sites were labeled with ferritin-conjugated goat anti-rabbit IgG and stained with phosphotungstic acid. Intense labeling of the rod outer segments was clearly achieved, whereas the cone outer segments were without label. Other parts of the retina, including the ellipsoid region of both rods and cones, were also without significant label. These regions provided an intrinsic control for the specificity of the antiserum and established the validity of the general technique.

Animals↗