Esterified estrogens with and without methyltestosterone decrease arterial LDL metabolism in cynomolgus monkeys

OBJECTIVES: To assess retinal complications and to identify risk factors for retinal complications following aqueous shunt procedures. MATERIALS AND METHODS: Records of 38 consecutive aqueous shunt procedures that were performed on 36 patients at the Eye Institute of the Medical College of Wisconsin, Milwaukee, from June 1993 to March 1995 (minimum follow-up, 6 months) were reviewed. The mean +/- SD follow-up was 11.4 +/- 5.2 months (median, 10.5 months). RESULTS: Twelve patients (32%) had the following retinal complications: 4 serous choroidal effusions (10%) that required drainage, 3 suprachoroidal hemorrhages (8%), 2 vitreous hemorrhages (5%), 1 rhegmatogenous retinal detachment (3%), 1 endophthalmitis (3%), and 1 scleral buckling extrusion (3%). Surgical procedures for retinal complications were required in 8 (67%) of these 12 patients. Visual acuity decreased 2 lines or more in 9 (75%) of these 12 patients. The median onset of a postoperative retinal complication was 12.5 days, with 10 patients (83%) experiencing complications within 35 days. Serous choroidal effusions developed in 10 other patients (26%), and these effusions resolved spontaneously. Visual acuity decreased 2 lines or more in 2 (20%) of these additional 10 patients. Patients who experienced serious retinal complications were significantly older, had a higher rate of hypertension, and postoperative ocular hypotony. Serious retinal complications were distributed evenly among patients with Krupin valves with discs and Molteno and Baerveldt devices. Experience with the Ahmed glaucoma valve implant was limited. CONCLUSION: Aqueous shunt procedures may be associated with significant retinal complications and subsequent visual loss.     

Anogenital papillomavirus infection and neoplasia in immunodeficient women

This article reviews the impact of infection with human immunodeficiency virus (HIV) on HPV infections and HPV-associated lesions of the female anogenital tract. Studies investigating HPV infections in HIV-seropositive women are presented as well as the possibility that HIV can influence HPV expression directly through molecular interactions between viral genes and indirectly through immunosuppression. Studies linking HIV infection to invasive cervical cancer and cervical intraepithelial neoplasia are reviewed; recommended protocols for cervical cancer screening in HIV-seropositive women for cervical disease also are presented.     

Menarcheal age in University of Warwick young women

The influence of ischemia on purine nucleotide and their catabolite concentration in human myocardium was investigated during surgery of acquired and congenital heart defects. This was compared with the influence of ischemia on rat heart. Concentrations of adenine and guanine nucleotides and their catabolites were measured in the extracts of heart biopsies taken at the onset of ischemia and at the time of reperfusion. The content of myocardial ATP in human heart decreased from the initial value of 22.3 +/- 1.1 to 14.6 +/- 1.5 nmol/mg protein and total adenine nucleotide pool decreased from 34.2 +/- 1.8 to 27.6 +/- 1.5 nmol/mg protein during the operation. Significant increases in myocardial concentrations of purine catabolites were also observed with the most prominent rise in inosine from below 0.5 at the onset of the ischemia to 3.0 +/- 0.5 nmol/mg protein at the time of reperfusion. A positive correlation was demonstrated between the concentration of purine catabolites in the heart at the end of ischemia with the decrease of both ATP and the total nucleotide pool. An interesting metabolic specificity of the ischemic human heart appeared to be only a small accumulation of inosine monophosphate (IMP). The increase of IMP in the rat heart after ischemia was several-fold higher. Thus, cardiac surgery of congenital and acquired heart defects was associated with a significant decrease in myocardial adenylate pool and a single biopsy collected at the end of ischemia seems to be sufficient to evaluate the extent of this metabolic and possibly functional impairment of the heart.     

Modulation of postural tremors at the wrist by supramaximal electrical median nerve shocks in essential tremor, Parkinson's disease and normal subjects mimicking tremor

The response of postural wrist tremors to supramaximal median nerve stimulation was examined in patients with hereditary essential tremor (n = 10) and Parkinson's disease (n = 9), and in normal subjects mimicking wrist tremor (n = 8). The average frequency of on-going tremor was the same in all three groups. Supramaximal peripheral nerve shocks inhibited and then synchronised the rhythmic electromyographic (EMG) activity of all types of tremor. The duration of inhibition ranged from 90 to 210ms, varying inversely with the frequency of on-going tremor. There was no significant difference in mean duration of inhibition or in the timing of the first peak after stimulation on the average rectified EMG records between the three groups. The degree to which supramaximal peripheral nerve shocks could modulate the timing of rhythmic EMG bursts in the forearm flexor muscles was also quantified by deriving a resetting index. No significant difference in mean resetting index of the three groups was found. These results suggest that such studies cannot be used to differentiate between the common causes of postural wrist tremors.     

N-acetylcysteine does not influence the activity of endothelium-derived relaxing factor in vivo

Nitric oxide forms complexes with an array of biomolecular carriers that retain biological activity. This reactivity of nitric oxide in physiological systems has led to some dispute as to whether endothelium-derived relaxing factors nitric oxide or a closely related adduct thereof, such as a nitrosothiol. In vitro bioassays used to address this question are limited by the exclusion of biological thiols that are requisite for nitrosothiol formation. Thus, the purpose of this study was to obtain insight into the identity of endothelium-derived relaxing factor in vivo. We reasoned that if endothelium-derived relaxing factor in nitric oxide, infusion of physiological concentrations of thiol would potentiate its bioactivity by analogy with effects seen in vitro, whereas nitrosothiol would be resistant to such modulation. We used venous-occlusion plethysmography to study forearm blood flow in normal subjects. Methacholine (0.3 to 10 micrograms/min) and nitroglycerin (1 to 30 micrograms/min) were infused via the brachial artery to elicit endothelium-dependent and endothelium-independent vasodilation, respectively. Dose-response determinations were made for each drug before and after an intra-arterial infusion of the reduced thiol, N-acetylcysteine, at rates estimated to achieve a physiological concentration of 1 mmol/L. Methacholine increased forearm blood flow in a dose-dependent manner. Infusion of N-acetylcysteine did not change the sensitivity (ED50, 1.7 versus 1.7 micrograms/min, P = NS) or maximal response to methacholine. In contrast, thiol increased the sensitivity to nitroglycerin (ED50, 4.7 versus 2.8 micrograms/min, P < .01). Thus, conflicting with reports in vitro, thiol does not modulate endothelium-derived relaxing factor responses in vivo. These data indicate that sulfhydryl groups are not a limiting factor for endothelium-derived relaxing factor responses in forearm resistance vessels in normal humans and are in keeping with reports that nitrosothiol contributes to endothelium-derived relaxing factor bioactivity in plasma and vascular smooth muscle. Potentiation of the effects of nitroglycerin by N-acetylcysteine can be attributed to its enhanced biotransformation to an endothelium-derived relaxing factor equivalent, such as nitrosothiol. These observations support the notion of an equilibrium between nitric oxide and nitrosothiol in biological systems that may be influenced by redox state.     

Allelotype analysis of uterine leiomyoma: localization of a potential tumor suppressor gene to a 4-cM region of chromosome 7q

The degree and nature of patient involvement in consultations with health professionals influences problem and needs recognition and management, and public accountability. This paper suggests a framework for understanding the scope for patient involvement in such consultations. Patients are defined as co-producers of formal health services, whose potential for involvement in consultations depends on their personal rights, responsibilities and preferences. Patients' rights in consultations are poorly defined and, in the National Health Service (NHS), not legally enforceable. The responsibilities of patients are also undefined. I suggest that these are not to deny, of their own volition, the rights of others, which in consultations necessitate mutuality of involvement through information-exchange and shared decision-making. Preferences should be met insofar as they do not militate against responsibilities and rights.     

Z/I and A-band lattice spacings in frog skeletal muscle: effects of contraction and osmolarity

A-band and Z-line/I-band lattice spacings were measured by small-angle X-ray diffraction from relaxed and isometrically-contracting whole frog sartorius muscles with lattice spacings reduced or swollen by changing the osmolarity of the bathing solution. A-band spacing increased by approximately 3% upon isometric contraction at reduced lattice spacings (245-356 mOsm) and decreased by approximately 1% at swollen spacings (172 mOsm), similarly to the behaviour of skinned muscles upon changing from the relaxed state to rigor. The Z/I lattice underwent a significant lattice expansion (3-8%) upon isometric contraction at all osmolarities, in qualitative agreement (but quantitative disagreement) with results from electron microscopy on mammalian skeletal muscle. Lattice areas calculated for the Z/I and A-band lattices indicate a barrel-shaped sarcomere in the resting state, which may provide a partial explanation for how longitudinal forces produced in the A-band can produce a radial expansive force in the Z-line during contraction. The radial component of cross-bridge stiffness was calculated from the A-band data for contracting muscle, using a lattice stability model incorporating structural, osmotic and electrostatic forces. The calculations gave a radial cross-bridge stiffness during contraction of about 9 x 10(5) N m-2, and outward radial force per thick filament in normal Ringer's solution of 6 x 10(-9) N, corresponding to a radial force per cross-bridge of 10(-11) N.     

The influence of advanced age on the outcome of assisted reproduction

This study investigates within-subject variations and associations of salivary viscosities and flow rates in a test panel of healthy adults. After several practice sessions, unstimulated and stimulated whole saliva samples were collected 5 times daily (at 0800, 1100, 1400, 1700, and 2000 h) from 30 university students. There was a significant within-subject variation in viscosity and flow rate of unstimulated saliva (P<0.001). Intra-item correlations were significantly different for salivary flow rates (r= 0.82 for unstimulated, r= 0.88 for stimulated, P< 0.001) and viscosity of unstimulated saliva (r= 0.54, P< 0.05), but viscosity of stimulated saliva was different in this respect. Our results indicate that there is a significant within-subject variation in viscosity of unstimulated saliva.