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Biomedical subjects

M Miller

Publications and source records attributed to M Miller.

At least 757 records · Page 42Linked to original sources

Action of cortisol introduced into the supraoptic nucleus, on vasopressin release and antidiuresis during hypertonic saline infusion in conscious rhesus monkeys.

In human subjects cortisol raises the osmotic threshold for vasopressin release. The presumption that this results from a direct inhibitory action of cortisol on osmotically stimulated vasopressin release has been tested in conscious rhesus monkeys. Preparatory surgical procedures included chronic bladder catheterization, placement of cannulae in the right atrium, the left jugular vein and the stomach and stereotaxic insertion of metal cannulae in both supraoptic nuclei. The osmotic threshold for vasopressin release was defined as the plasma osmolality at the beginning of the 3 min urine sample in which free water clearance first fell by greater than 2 SD below the mean control level, in response to 5% saline infusion during constant hydration. Compared with control substances (0.9% saline solution or 11-deoxycortisol crystals), cortisol solution or crystals introduced into both supraoptic nuclei significantly lowered the plasma osmolality during the water-induced pre-saline diuresis, so that a larger amount of 5% NaCl infusion was required to reach the osmotic threshold. Thus, cortisol introduced into the supraoptic nuclei prolonged the duration of 5% saline infusion needed to reach the osmotic threshold, and raised the increment in plasma osmolality needed to reach the threshold but cortisol did not significantly raise the absolute level of the threshold.

Animals↗

Agonist and antagonist activity of en-clomiphene upon oestrogen-mediated events in the uterus, pituitary gland and brain of the rat.

The oestrogen agonist and antagonist activity of a single dose of en-clomiphene (0.5--50 mg/kg) was studied in peripheral and brain tissue in the 3 week ovariectomized rat. 17 beta-Oestradiol benzoate (100 microgram/kg) or vehicle was injected 24 h after en-clomiphene administration and data collected at 72 h. En-clomiphene produced a dose-related (agonist) fall in body weight and food intake. Agonist action was not observed upon sexual receptivity and prolactin secretion; oestrogen antagonism of these parameters was only seen at the higher doses. The effects of en-clomiphene upon serum LH and FSH were complex, both agonist and antagonist activity being demonstrated in the absence and presence of oestrogen. En-clomiphene was uterotrophic at all doses tested; however, oestrogen antagonism was only seen at the higher doses. Inhibition of the accumulation of uterine luminal fluid at the higher doses of en-clomiphene was a sensitive index of oestrogen antagonism. The results are discussed in relation to previous studies of the effects of en-clomiphene on oestrogen receptors. With the exception of the antagonism of oestrogen-induced sexual receptivity no correlation could be made between biological activity and the status of oestrogen receptors in tissue.

Animals↗

Implementation strategies for an inpatient women's support group.

The authors believe an inpatient women's group to be a supportive and educative nursing intervention that, when adjunctively combined with other inpatient therapy forms, assists women to resolve sex-role conflicts. Use of the nursing audit, review of relevant literature, development of a group philosophy, objectives, and appropriate credentialing of nurse group facilitators are strategies that maximize group effectiveness. Moreover, group content, which is determined from the client's perspectives of need, and evaluated by behavioral changes among client participants, insures sustained program relevancy.

Adult↗

Multicenter comparative evaluation of netilmicin and gentamicin in adult patients. Efficacy and safety.

Netilmicin and gentamicin were compared in a multicenter clinical trial in 12 study locations. The two aminoglycosides were randomly assigned to hospitalized adult patients with systemic infections, and were administered by i.m. injection or slow i.v. infusion in divided doses generally calculated to deliver either 4-6.5 mg/kg per day of netilmicin, or 3-5 mg/kg per day of gentamicin. Lower dosages were given to patients with impaired renal function. Data from 210 patients receiving netilmicin and 212 receiving gentamicin were analyzed for efficacy. Favorable bacteriologic responses occurred in 95.5% (255/267) of the netilmicin-treated sites and in 90.1% (247/274) of the gentamicin-treated sites (p = 0.05). Netilmicin eliminated or reduced 95.6% (283/296) of all pathogens isolated from all infection sites compared with 89.5% (289/323) for gentamicin (p = 0.012). Favorable clinical responses were observed in 94.2% (275/292) of the netilmicin-treated patients and 89.5% (289/323) of the gentamicin-treated patients. Data from 377 netilmicin-treated patients and 378 gentamicin-treated patients were analyzed for safety. Evidence of nephrotoxicity probably related to treatment was observed in 8 of the netilmicin-treated patients and 14 of the gentamicin-treated patients. Audiometrically documented hearing loss probably related to treatment was observed in one gentamicin-treated patient. In one netilmicin-treated patient there were transient auditory and vestibular effects. Local tolerance to parenteral administration of the two drugs was excellent.

Adolescent↗

Metabolic abnormalities associated with diabetes mellitus, as investigated by gas chromatography and pattern-recognition analysis of profiles of volatile metabolites.

Patterns of volatile metabolites in urine, as obtained by glass-capillary gas chromatography, were investigated by use of a nonparametric pattern-recognition method, in an effort to detect abnormalities associated with diabetes. We used threshold logic unit analysis on a data set consisting of normal subjects and those with diabetes mellitus, and could predict patterns for volatile metabolites as belonging to the proper class in 94.83% of the cases examined. In addition, a feature-extraction algorithm isolated those volatile constituents that are most useful in making the normal/diabetic classification. We used gas chromatography/mass spectrometry to identify important profile constituents. Finally, these same pattern-recognition methods indicated strong sex-related patterns in these volatiles.

Chromatography, Gas↗

Increased risk of recurrence of pregnancies complicated by fetal neural tube defects in mothers receiving poor diets, and possible benefit of dietary counselling.

One hundred and seventy-four women who had previously had a child with a neural-tube defect were assessed retrospectively on the quality of their diets during the first trimester of that pregnancy, between pregnancies, and during the first trimester of other pregnancies. They were then studied prospectively during the first trimester of 186 following pregnancies and the outcome of these was recorded. One hundred and three women (with 109 pregnancies) were given dietary counselling before the pregnancy, the remaining 71 (with 77 pregnancies) not being counselled. Seventy-eight (72%) of the counselled women improved their diet compared with only nine (12%) of the uncounselled women. The difference was significant (p < 0.001). There were three recurrences of neural-tube defects in the counselled women (3%) and five recurrences in the uncounselled (7%). Although this difference was not significant, the relative risk in the counselled group was reduced to less than half of that in the uncounselled group. All eight recurrences occurred in the 45 pregnancies in women taking poor diets (18%), whereas there were no recurrences in the 141 other pregnancies. This difference is significant (p < 0.001). It is concluded that women receiving adequate diets have a lower incidence and recurrence of fetal neural-tube defects than women receiving poor diets and that dietary counselling may be effective in reducing the incidence of fetal neural-tube defects.

Counseling↗

Prediction of relapse in hyperthyroid Graves' disease.

Within a year of stopping a 6-month course of carbimazole treatment 41 of 65 patients (63%) with hyperthyroid Graves' disease had a recurrence of their hyperthyroidism. By combined analysis of the HLA-DRw3 status and the level of thyrotrophin-receptor antibody at the time of drug withdrawal relapse or remission could be predicted in 62 of the 65 patients.

Adult↗

Abnormalities in water homeostasis in small cell anaplastic lung cancer.

Forty-one patients with newly diagnosed small cell anaplastic lung cancer were evaluated for abnormalities in water homeostasis. Each patient underwent a standard water load (SWL) test. Overall, 68% had abnormalities in the SWL test. Abnormalities were found in 47% of the patients with carcinoma clinically limited to one hemithorax and in 86% of the patients with more extensive carcinoma. The determination of urinary antidiuretic hormone levels was available for 27 patients. Abnormally elevated levels were found in 44% of those patients. Forty-six patients had clinically detectable syndrome of the inappropriate secretion of antidiuretic hormone (SIADH); in 12% of patients water restriction was necessary. The incidence of detectable abnormalities in water homeostasis in this study was higher than has been previously recognized. The SWL test is a sensitive and useful means of determining the presence of impaired water handling in patients with small cell carcinoma of the lung.

Blood Urea Nitrogen↗

[Aflatoxin M1 in milk and milk products. A comparison of some determination procedures].

Usual TLC-methods for the determination of Aflatoxin M1 in milk and milk products sometimes do not separate interfering substances with similar optical and chemical properties from Aflatoxin M1, thus leading to considerably incorrect results. Even after an additional clean-up on polystyrene column the solutions contain so many compounds that the identification of Aflatoxin M1 is difficult. The resolving power of HPLC yield pure frations, which may be determined by their MS and UV spectra.

Aflatoxin M1↗

The effects of tetraalkylammonium salts on helix-coil transition parameters in natural and synthetic ribo- and deoxyribo-polynucleotides.

Thermal transition profiles were recorded for a variety of natural and synthetic DNA and double-stranded RNA preparations in the presence of tetramethylammonium (TMA+) and tetraethylammonium (TEA+) cations. Double-stranded RNAs of natural origin, with GC contents of 50% exhibited the same profiles and Tm values as native DNA containing normal bases. Hence the tetraalkylammonium cations liquidate not only the effects of base composition, and the difference in stability between A-T and A-U base pairs (further confirmed by measurements with uracil-containing DNA from phage PBS-2), but also that of the 2'OH. In the presence of TMA+ cations, there is very marked enhancement of the stability of U-U base pairs in poly(rU) and poly(Um). In 2.4 M TEA, the 1:1 complex of poly(G) with poly (C) formed readily and melted reversibly with a Tm as low as 87 degrees C. At concentrations of TMA and TEA for which dTm/dXGC = 0, the Tm values for various phage DNA preparations containing atypical bases (phages T2, T4, phi e, phi W-14, PBS-2) differ appreciably from those with 'normal bases'. Analysis of these findings indicates that the selective interaction of TMA and TEA cations with A-T base pairs occurs in the minor groove of the DNA helix. The overall results show that the action of these quaternary ammonium cations is not due exclusively to preferential binding to A-T base pairs, but must involve other factors, including modifications of solvent structure. They also underline the utility of TMA and TEA solvent systems for placing in evidence transition profiles not accessible in other solvent systems.

DNA↗