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Biomedical subjects

R London

Publications and source records attributed to R London.

At least 55 records · Page 3Linked to original sources
PubMed1983

Serum unconjugated estriol concentrations before and after the oxytocin challenge test: an index of fetal well-being.

Serum unconjugated estriol concentrations before and after the oxytocin challenge test (stress test) were measured in 54 high-risk, obstetric patients. Six of the stress test results were positive, and eight were equivocal. Eleven patients demonstrated decrements in estriol of greater than or equal to 25% after stress tests, and the infants of six of these patients demonstrated perinatal morbidity. Three patients exhibited positive stress test results but had estriol concentrations which were unaltered by the stress test; all were delivered vaginally of healthy infants shortly after the stress test. The coefficient of correlation between the stress test and perinatal outcome was 0.58 (P less than 0.001). When the estriol and stress test results were combined to predict outcome, a multiple correlation coefficient of 0.71 was obtained (P less than 0.001). This increment represents a significant (P less than 0.001) and substantial (18%) improvement in the prediction of perinatal outcome. These findings indicate that the measurement of changes in estriol with the stress test significantly improves one's ability to define the fetus at risk.

Estriol↗
PubMed1983

Regulation of intracellular chloride activity during perfusion with hypertonic solutions in the Necturus proximal tubule.

In a previous study we presented evidence that chloride transport across the basolateral membrane in Necturus proximal tubule cells occurs predominantly via exchange for both Na+ and HCO3-. In this study the regulation of intracellular chloride was further examined in the doubly-perfused kidney preparation using conventional and chloride-sensitive microelectrodes. Application of hypertonic basolateral solutions containing 80 mM raffinose stimulated an efflux of chloride such that chloride activity remained unchanged at control levels. Membrane potential did not change in these experiments. Inhibition of Cl- exit across the basolateral cell membrane by removal of either HCO3- or Na+ from the perfusion solution resulted in a significant increase in intracellular chloride activity, aiCl, when basolateral osmolarity was raised. Hypertonic basolateral solutions also produced a significant rise in aiCl in the presence of SITS. This study provides further evidence that chloride is transported across the basolateral cell membrane in exchange for both Na+ and HCO3-. Since this exchange mechanism is activated in response to hypertonic solutions, these studies suggest a functional role for this exchanger in the regulation of aiCl in the Necturus proximal tubule cell during volume changes.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1983

Chloride transport across the basolateral cell membrane of the Necturus proximal tubule: dependence on bicarbonate and sodium.

The transport of chloride across the Necturus proximal tubule cell was studied in the doubly-perfused kidney using conventional, chloride-sensitive and pH-sensitive microelectrodes. Lowering chloride activity in the basolateral solution results in a reduction in intracellular Cl- activity (aiCl). This reduction in aiCl is inhibited by removing either HCO-3 or Na+ from the perfusion solution, indicating that both HCO-3 and Na+ are required for Cl- movement across the basolateral cell membrane. Reducing either HCO-3 or Na+ in the basolateral solution causes an increase in aiCl. Thus changes in either Na+ or HCO-3 chemical gradients across the basolateral cell membrane significantly affect chloride movement. Changing intracellular pH by means of NH4Cl exposure results in an increase in aiCl followed by a sharp decrease when NH4Cl is removed. These changes in intracellular chloride do not occur in the absence of HCO-3. Likewise, the decrease in aiCl following NH4Cl treatment requires the presence of Na+ in the basolateral solution. We conclude that chloride is transported across the basolateral cell membrane in exchange for both Na+ and HCO-3. Our results also support the presence of a Na+/Cl- cotransport mechanism on the apical cell membrane.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1983

Episiotomy pain: efficacy and safety of fluproquazone compared to aspirin and placebo.

The analgesic efficacy of fluproquazone at 100 mg and 200 mg doses, was measured in 160 patients with episiotomy pain and was compared to that of aspirin (650 mg) and placebo. The 100-mg dose of fluproquazone was more effective in relieving episiotomy pain than the 200-mg dose of fluproquazone, aspirin or placebo in terms of mean pain intensity scores after 1 h. All active compounds were more effective than placebo by all criteria.

Adolescent↗
PubMed1983

Unilateral absence of a pulmonary artery.

Congenital absence of a main pulmonary artery is a rare anomaly. Most patients without associated congenital cardiac abnormalities are asymptomatic, and the diagnosis is first suggested by the appearance of the involved lung on a routine chest roentgenogram. The ipsilateral lung will be smaller than normal, and the contralateral lung will be overinflated and may herniate across the midline. We describe eight children with unilateral pulmonary arterial atresia (seven on the right side, four of whom were without associated cardiac anomalies).

Adolescent↗
PubMed1983

Role of cholecystokinin in the gastrocolonic response to a fat meal.

The fat component of the meal is the major stimulant of the gastrocolonic response. The aim of this study was to characterize the mechanism of the gastrocolonic response after eating fat in healthy human volunteers. A bipolar clip electrode recorded spike activity (SP) from the distal colon. An immediate increase in colonic spike activity occurred after eating a fat meal (18.0 +/- 3.0 SP/30 min) (p less than 0.02). Spike activity remained elevated for 90 min after eating the fat meal (18.6 +/- 2.7 SP/30 min) (p less than 0.01). The intravenous infusion of naloxone or atropine inhibited the fat-induced increase in colonic motility. Cholecystokinin is a candidate mediator of the fat-stimulated gastrocolonic response. The intravenous infusion of the octapeptide of cholecystokinin (20 ng/kg . h) stimulated an increase in distal colonic spike activity (16.0 +/- 3.7 SP/30 min) (p less than 0.025). Intravenous atropine did not affect stimulation of colonic motility by the octapeptide of cholecystokinin. Continuous infusion of naloxone, however, did inhibit stimulation of colonic spike activity by the octapeptide of cholecystokinin. There was no cross-reactivity between opiate or muscarinic receptors. These data suggest (a) fat stimulation of the gastro-colonic response required a muscarinic and opiate receptor, and (b) octapeptide of cholecystokinin can stimulate colonic motility, but it is not the major mediator of the gastrocolonic response.

Adult↗
PubMed1982

An evaluation of the monocular estimate method of dynamic retinoscopy.

Monocular Estimate Method (MEM) dynamic retinoscopy is an objective clinical method for determining the accommodative response to a fixed accommodative stimulus. Although MEM has been used in many clinical investigations, it has never been compared with the measurement of accommodative response by the haploscope. This report compares the accommodative responses obtained by MEM and by a haploscopic instrument, the phoroaccommodometer. Linear regression analysis indicates that MEM consistently provides a close approximation to the phoroaccommodometer finding (r = 0.975, p less than 0.001). A conversion table has been generated so MEM findings may be adjusted to correspond with the phoroaccommodometer at higher stimulus values.

Accommodation, Ocular↗
PubMed1982

Changes in angle lambda during growth: theory and clinical applications.

The eye undergoes rapid growth during the first years of life. Using a mathematical model, we analyzed angle lambda from birth through adult life to determine what change in its magnitude occurs with growth of the eye. The effect of changes in angle lambda on measurement and correction of astigmatic errors and on the analysis of fixation patterns are discussed.

Adult↗
PubMed1982

Congenital esotropia--a documented case report.

Criteria for defining congenital esotropia and its cure are related to a documented case history. A congenitally esotropic child had strabismus surgery at age 13 months. At 11 years of age the had 20 delta of left exotropia. One year of vision training enabled her to achieve some stereopsis but she retained a small angle asotropia whenever the controlled her exophoric tendency.

Accommodation, Ocular↗
PubMed1982

Optokinetic nystagmus: a review of pathways, techniques and selected diagnostic applications.

There are a myriad of conditions producing abnormal OKN responses. In most of these conditions the diagnosis can be made without recourse to OKN. However, in the five conditions described in this paper (suspected poor visual acuity in infants and young children, parietal lesions, subclinical internuclear ophthalmoplegia, Parinaud's syndrome, and aberrant regeneration of the third nerve) OKN can greatly facilitate the diagnosis. A review of the neural pathways of the OKN response and an explanation of the various equipment and techniques used to assess OKN are included.

Brain Diseases↗
PubMed1982

Relationship between fixation disparity curves and symptoms in monofixators.

Patients with small angle strabismus usually are asymptomatic. Occasionally, however, binocular asthenopic symptoms are reported. Two monofixators, one symptomatic and the other asymptomatic, with similar profiles on strabismic evaluation had forced vergence Fixation Disparity Curves (FDC) measured. Slope of the FDC may help to discriminate between the symptomatic and asymptomatic patient.

Adult↗
PubMed1981

alpha-Tocopherol and serum lipoproteins.

Twenty-six patients with clinically confirmed mammary dysplasia and five age-matched controls were treated with alpha-tocopherol, 600 mg/day. Serum samples collected on the 21st day of the menstrual cycle were analyzed for cholesterol in lipoprotein fractions, isolated by a combination of precipitation and ultracentrifugation techniques. Eighty-five percent of patients showed objective and subjective remission from disease following therapy. In mammary dysplasia patients, the ratio of serum cholesterol/high density lipoprotein cholesterol was higher than those in age-matched controls, an abnormality which was corrected by alpha-tocopherol therapy. Furthermore, as a result of therapy, high density lipoproteins increased and ester cholesterol associated with low density lipoproteins decreased. The results suggest that alpha-tocopherol may serve as an effective agent in treating patients with benign disease, as well as correct the inherent abnormality in serum cholesterol distribution in mammary dysplasia patients.

Breast Diseases↗
PubMed1981

Problem orientation in vision therapy.

Quantification and retrieval of data in vision therapy is a difficult task for both the private practitioner and optometric educator. The problem-oriented record provides an organizational approach that readily identifies patient's problems, therapeutic objectives, and the results of administered therapy. A minimum data base and the resultant problem list for vision therapy has been designed by us. By combining these two through a system of coding, a ready computer data retrieval system was devised. This system provides a method to clearly define terms, objectives, and results. Utilization of this record system by optometric schools and practitioners should reduce much of the confusion existing in the specialty field of vision therapy.

Amblyopia↗
PubMed1981

Serum hormones and lipoproteins in benign breast disease.

Seventeen young women with clinically confirmed mammary dysplasia and six age-matched controls were treated with alpha-tocopherol. Serum samples collected during the luteal phase of each woman at monthly intervals for the 4-month duration of the study were analyzed for serum luteinizing hormone, follicle-stimulating hormone, and prolactin concentrations by radioimmunoassay and for lipoprotein levels by a combination of precipitation, ultracentrifugation, and enzymatic techniques. Fifteen patients showed objective and subjective remission from disease. While prolactin levels did not change significantly, elevated levels of luteinizing and follicle-stimulating hormones were decreased to normal levels. Ratios of serum cholesterol to high-density lipoprotein cholesterol decreased; high-density lipoprotein and free cholesterol associated with low-density lipoproteins increased as a result of therapy. The results suggest that alpha-tocopherol may serve as an effective agent not only to treat patients with benign breast disease but also to normalize abnormal hormone and lipid levels in subjects at high risk for breast cancer.

Breast Diseases↗