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M Bower

Publications and source records attributed to M Bower.

116 records · Page 7Linked to original sources

Neurohypophysial secretion to insulin-induced hypoglycemia and its regulation by endogenous opioids in women.

In animals, there is sexual dimorphism of both neurohypophysial peptide secretion in response to stressful stimuli and to the inhibitory effects of opioids. In men, endogenous opioids inhibit the release of oxytocin when AVP secretion is stimulated by insulin-induced hypoglycemia. We have now investigated the role of endogenous opioids in the AVP and oxytocin response to insulin-induced hypoglycemia in women. Twelve subjects, 6 in the follicular and 6 in the luteal phase of the menstrual cycle, were infused on 2 occasions with naloxone (4 mg bolus and 6 mg/h) or saline. Soluble insulin (Human Actrapid, 0.15 mu/kg, iv) was given and serial blood samples taken. Blood sugar fell significantly (p less than 0.05) and similarly in all groups. In the follicular phase hypoglycemia led to a rise in plasma AVP from 1.3 +/- 0.2 to 1.8 +/- 0.2 pmol/l in the saline-infused subjects (NS), and from 1.0 +/- 0.1 to 2.0 +/- 0.2 pmol/l in the naloxone-infused (p less than 0.05). AVP rose similarly from 0.6 +/- 0.1 to 1.6 +/- 0.5 pmol/l (p less than 0.05) in the luteal phase controls and from 0.8 +/- 0.1 to 1.5 +/- 0.3 pmol/l (p less than 0.05) in naloxone-infused subjects in the luteal phase. There were no significant differences between any of these groups. There were no significant changes in plasma oxytocin in any group. We therefore conclude that in women, unlike men, endogenous opioids do not modulate oxytocin or vasopressin release during insulin-induced hypoglycemia.

Arginine Vasopressin↗

The automatic implantable cardioverter/defibrillator for a life threatening arrhythmia in a case of post-partum cardiomyopathy.

We report the development of severe life threatening polymorphic ventricular tachycardia in a young woman shortly following her first pregnancy, who ultimately required the insertion of an automatic implantable cardioverter/defibrillator because of the failure of conventional antiarrhythmic therapy. Although only about 7 patients have received units in the UK to date, the experience in the USA, where up to 300 per month may be implanted, suggests that they will become a more common method of treatment in cases of life threatening arrhythmias.

Adult↗

Oligodeoxyribonucleoside methylphosphonates. NMR and UV spectroscopic studies of Rp-Rp and Sp-Sp methylphosphonate (Me) modified duplexes of (d[GGAATTCC])2.

1H NMR chemical shift assignments for the title compounds were made for most of the 1H signals using two-dimensional nuclear Overhauser effect (2D-NOE) data, which were also used to establish the absolute configuration at the modified phosphorus. The chemical shifts were similar to those reported [Broido, M.S., et al. (1985) Eur. J. Biochem. 150, 117-128] for the unmodified, parent, B-type duplex [d(GGAATTCC)]2. Differences in chemical shifts were mostly localized to the nucleotides on the 5'- and 3'-sides of the modified phosphorus. The Rp-Rp isomers exhibited UV-derived Tm values similar to that of the parent duplex. On the other hand, the Sp-Sp isomers generally exhibited lower Tm values which correlated with P-CH3--H3' (n-1 nucleotide) cross peak intensities and 31P spectral parameters. The combined data argue for increased steric interactions with the Sp-P-Me methyl group as the modification position is moved toward the center of the oligomer. All of the Tm results can be explained in terms of three factors which result from replacement of a phosphate by a methylphosphonate group: reduction of oligomer charge; electronic and other substituent effects; steric interactions.

Deoxyribonucleosides↗

Synthesis and characterization of oligodeoxyribonucleotides containing terminal phosphates. NMR, UV spectroscopic and thermodynamic analysis of duplex formation of [d(pGGAATTCC)]2, [d(GGAATTCCp)]2 and [d(pGGAATTCCp)]2.

Derivatives of the oligomer [d(GGAATTCC)]2 with 5' (5'-P), 3' (3'-P) and both 5' and 3' (5',3'-P2) terminal phosphate groups have been synthesized and studied by temperature dependent UV and NMR spectroscopic methods. Thermodynamic studies of the helix to strand transition indicate that addition of 3' phosphate groups has very little effect on the delta G degree for helix formation at 37 degrees C while addition of 5' phosphate groups adds approximately -0.5 kcal/mole to the delta G degree for duplex formation. The helix stabilization by 5' phosphate groups occurs at salt concentrations of 0.1 M and above, and is primarily enthalpic in origin. Tm studies as a function of ionic strength also indicate that the oligomers fall into two groups with the parent and 3'-P derivatives being similar but less stable than the 5'-P and 5',3'-P2 derivatives. Imino proton and 31P NMR studies also divide the oligomers into these same two groups based on spectral comparisons and temperature induced chemical shift and linewidth changes. 31P NMR analysis suggests that addition of 5' phosphate groups results in a small change in phosphodiester torsional angles in the g,t to g,g direction, indicating improved base stacking at the 5' end of the modified oligomer. No such changes are seen at the 3' end of the oligomer on adding 3' phosphate groups.

Magnetic Resonance Spectroscopy↗

Penicillin in the treatment of skin sores in children.

Skin infections are a common cause of morbidity in children, particularly in tropical areas. Cultures from such lesions often grow both penicillin-resistant staphylococci and penicillin-sensitive streptococci. In a controlled trial of the treatment of septic skin lesions in 227 paediatric outpatients at Goroka Hospital, sequential analysis of the response to treatment showed that washing plus the intramuscular administration of procaine penicillin was more effective than washing plus placebo (P less than 0.05) after the 25th preference had been decided. When the amount of healing in the two groups was compared, washing plus penicillin was again more effective than washing plus placebo (P less than 0.001; Wilcoxon's rank-sum test). Because it eradicates beta-haemolytic streptococci, penicillin is a safe and effective agent for the treatment of large, multiple, or badly infected skin sores, even in countries such as Australia and Papua New Guinea in which most staphylococci are resistant to penicillin.

Bacterial Infections↗

The bacteriology of skin sores in Goroka children.

The bacteriology of infected skin lesions was studied in paediatric outpatients. Thirty-nine untreated lesions were studied: 37 (95%) grew beta haemolytic streptococci (46% group A, 3% group B, 23% group C, 26% group G), 21 (54%) grew Staphylococcus aureus and 13 (33%) grew Corynebacterium haemolyticum. No attempt was made to selectively isolate Corynebacterium diphtheriae in this study. Vincent's organisms were seen in 13 (37%) of 35 gram stains from untreated lesions, including eight (73%) of 11 tropical ulcers. Twenty-three (92%) of the 25 strains of S. aureus isolated from untreated sores were resistant to penicillin.

Child↗