Bimatoprost: a novel antiglaucoma agent.

The aim of glaucoma therapy is to preserve vision by reducing intraocular pressure (IOP). Following recent National Eye Institute sponsored studies, it is becoming increasingly apparent that every mmHg of extra IOP lowering counts. Bimatoprost is the newest and most effective addition to the physician's armamentarium of ocular hypotensive drugs. Direct clinical comparisons have demonstrated that it is more efficacious than the prostaglandin (PG) FP receptor agonist prodrugs, latanoprost and travoprost, as well as a beta-adrenoceptor antagonist, timolol, alone or in fixed combination with the carbonic anhydrase inhibitor, dorzolamide. Moreover, patients that are refractory to latanoprost therapy may be successfully treated with bimatoprost. Such evidence provides support, at the clinical level, for the contention that bimatoprost is pharmacologically distinct from PG FP receptor agonist prodrugs. Bimatoprost is a structural analog of PGF2alpha-ethanolamide (prostamide F2alpha), which is formed from the endocannabinoid anandamide by a biosynthetic pathway involving cyclooxygenase-2 (COX-2). Their pharmacology is remarkably similar, such that bimatoprost may be regarded as a prostamide mimetic. The target receptor for bimatoprost and the prostamides appears unique and unrelated to PG- and endocannabinoid-sensitive receptors. Extensive ocular distribution/metabolism studies in non-human primates demonstrate that bimatoprost is not a prodrug, it remains essentially intact. Its profound ocular hypotensive effects may, therefore, be attributed to its prostamide-mimetic properties.

A compact respiratory-triggering device for routine microimaging of laboratory mice.

A partial-body plethysmograph was developed for measuring the respiratory flow of anesthetized mice during routine microimaging experiments performed in the close confines of an 89-mm-diameter, vertical-bore magnet. Respiratory flow patterns were used for synchronizing conventional T2-weighted spin-echo imaging with the respiratory cycle, thereby, significantly reducing motion-induced artifacts and increasing observed liver lesion contrast.

Acute inhalation toxicity of neutralized chemical agent identification sets (CAIS) containing agent in chloroform.

An acute head-only inhalation study was conducted in rats exposed for 1 h to product solution (wastestream) resultant from the chemical neutralization of Chemical Agent Identification Sets (CAIS) containing agent (sulfur mustard (HD), nitrogen mustard (HN-1) or lewisite (L)) in chloroform. Groups of Sprague-Dawley rats were exposed to varying concentrations (24000, 18000, 12000 or 6000 ppm) of CAIS wastestream. An additional group was exposed to the vehicle (chloroform/t-butanol) only, at a concentration equivalent to the concentration of vehicle at the highest exposure level. Animals were evaluated for toxic effects, including assessment of toxicant-induced alterations to the ocular and respiratory systems. Mortality on exposure to 24000 ppm of test article or to vehicle alone was high. Mortality in the other exposure groups was roughly proportional to the concentration of test article (wastestream). Toxic signs were consistent with exposure to solvent system components (chloroform/t-butanol) and to agent decomposition products/by-products. Incidence and severity of ocular effects were similar in vehicle control and treatment groups. The salient respiratory effect observed was a decreased minute volume, which was also noted in vehicle and treatment groups.

Effect of pregnancy on renal function in patients with moderate-to-severe diabetic renal insufficiency.

OBJECTIVE: Previous studies of patients with diabetic nephropathy and mild renal impairment have suggested no determination in renal function as a result of pregnancy. The objective of this study was to determine whether pregnancy may permanently worsen renal function in women with diabetic nephropathy and moderate-to-severe renal insufficiency. RESEARCH DESIGN AND METHODS: Eleven patients were identified with diabetic nephropathy and moderate-to-severe renal dysfunction (creatinine [Cr] > or = 124 mumol/l [1.4 mg/dl]) at pregnancy onset by retrospective chart review. Alterations in glomerular filtration rate were estimated by using linear regression of the reciprocal of Cr over time. An equal number of nonpregnant premenopausal type 1 diabetic women with similar degrees of renal dysfunction served as a comparison group for nonpregnant rate of decline of renal function and potential contributing factors. RESULTS: Mean serum Cr rose from 159 mumol/l (1.8 mg/dl) prepregnancy to 221 mumol/l (2.5 mg/dl) in the third trimester. Renal function was stable in 27%, showed transient worsening in pregnancy in 27%, and demonstrated a permanent decline in 45%. Proteinuria increased in pregnancy in 79%. Exacerbation of hypertension or preeclampsia occurred in 73%. Seven patients progressed to dialysis 6-57 months postpartum, with 71% (five of seven) of these cases attributed to acceleration of disease during the pregnancy. Student's tests and repeated-measures analysis of variance support a pregnancy-induced acceleration in the rate of decline of renal function. CONCLUSIONS: In this series, patients with diabetic nephropathy and moderate-to-severe renal insufficiency were found to have a > 40% chance of accelerated progression of their disease as a result of pregnancy.

Caloric restriction in gestational diabetes mellitus: when and how much?

Variations in nutritional intake during pregnancy have measurable effects on the circulating levels of maternal nutrients, maternal weight gain, and birth weight of the offspring. A growing body of evidence indicates that alterations in maternal metabolism can also have long-term consequences in the offspring in relation to adult adiposity, glucose tolerance, and perhaps intellectual development. Therefore, recommendations for diet during pregnancy must be made with great care, and with as much scientific understanding as possible. Nutritional advice traditionally given to all pregnant women, including those with gestational diabetes mellitus (GDM) or noninsulin-dependent diabetes, does not allow for individual differences in caloric needs as a function of the degree of maternal obesity and thus, may encourage excessive weight gain. Evidence reviewed below suggests that adjusting caloric intake to meet new guidelines for weight gain during pregnancy may be advantageous in reducing maternal blood sugar and insulin levels, without producing abnormalities in other metabolic variables. Modest caloric reduction which limits excessive weight gain in the mother may also be associated with a small reduction of fetal weight. However, more stringent dietary manipulations in obese gravida should be discouraged as a routine measure until more knowledge is available from large-scale clinical trials about their effects on the entire panoply of maternal nutrients and their impact on the offspring.

A new method for obtaining electrocardiograms in unrestrained crocodilian reptiles.

A new procedure is described for acquiring measurements of electrocardiographic parameters in unrestrained crocodilians. These measurements are difficult to obtain in freely moving animals; hence, electrocardiographic activity under natural conditions has not been previously quantified. In this investigation, twelve American alligators were equipped with subcutaneous electrodes. The lead wires were sutured to each animal's skin and the extracutaneous wires coiled and held in place against the animals' dorsal surfaces with waterproof elastic bandages. The electrodes were connected to an ECG analyzer only at the time of measurement. The presence of the leads and harness did not appear to interfere with the movements of the animals either in the animal room or during testing. This method allows for more precise measurements of cardiac activity under conditions which closely resemble those of crocodilians in their natural state.

The nursing care technician program. An education process for nurse extenders.

The Nursing Care Technician Program at Ochsner Foundation Hospital in New Orleans, Louisiana, is specifically designed to enable the nurse to plan, provide, and evaluate patient care while delegating tasks to assistive personnel. This article describes the institution's approach to role development, reviews the planning, implementation, and evaluation process, and provides an analysis of associated costs, benefits, and patient outcomes of the program.

A working model for nursing staff development.

A working model for nursing staff development used currently in a major teaching hospital in the south is presented. It explores six challenges facing hospital education departments and, using the model as a framework, provides strategies for effective interventions and creative solutions to the problems facing nursing currently.

Changes in diabetic retinopathy during pregnancy. Correlations with regulation of hyperglycemia.

Thirty-eight pregnancies in 35 women with insulin-dependent diabetes mellitus were monitored for changes in diabetic retinopathy during the institution of "tight" metabolic control by intensive medical management. Eye findings were scored on paired sets of retinal photographs obtained when enrolled in this study and shortly after delivery. These findings were then correlated with measurements of diabetic regulation. Intensive therapy for the diabetes mellitus resulted in improved glucose control by the time of delivery. However, retinal abnormalities worsened as gestation proceeded in 55% of the pregnancies. Deterioration of background retinopathy correlated significantly with the levels of plasma glucose at entry and with the magnitude of improvement in glycemia achieved during the first six to 14 weeks after entry (ie, "early changes") and by the final week before delivery (ie, "overall changes"). Our findings indicate that the changing retinopathy during pregnancy cannot be interpreted without assessment of concurrent changes in the regulation of maternal diabetes and that the abrupt institution of improved diabetic control during pregnancy may be one factor in the deterioration of background retinopathy sometimes seen during pregnancy.

Gestational diabetes mellitus: a syndrome with phenotypic and genotypic heterogeneity.

One hundred ninety-nine gravida with gestational diabetes mellitus (GDM) defined as "carbohydrate intolerance of varying severity with onset or first recognition during pregnancy" have been stratified into subgroups on the basis of fasting plasma glucose and evaluated for further phenotypic and genotypic heterogeneity. A significantly greater proportion of the women in all our groups were older and heavier than in a "control" population of 148 consecutive gravida with documented normal oral glucose tolerance. After correction for age and weight by covariate analysis, absolute insulinopenia in response to oral glucose could be demonstrated in all GDM groups, although exceptions were present in each. The incidence of diabetes in the mothers of our patients with GDM was 8-fold greater than in controls; the incidence in fathers did not deviate from control patterns. HLA-DR3 and DR4 antigens were more frequently present in GDM and the increase was statistically significant in blacks. At the time of diagnosis, cytoplasmic islet cell antibodies (ICA) were significantly more common in GDM associated with elevated fasting plasma glucose than in controls; the frequency of ICA was 18.4% (7/38) in women with fasting plasma glucose greater than or equal to 130 mg/dl. Our findings indicate that GDM entails genotypic as well as phenotypic diversity and may include patients with slowly-evolving Type I diabetes mellitus, as well as patients with Type II diabetes mellitus, and women with asymptomatic diabetes which antedated the pregnancy (i.e. pregestational diabetes mellitus). Appreciation of this heterogeneity should be incorporated into any evaluation of intervention strategies for women with GDM or into prognoses concerning their postpartum metabolic status.

Gestational diabetes mellitus. Heterogeneity of maternal age, weight, insulin secretion, HLA antigens, and islet cell antibodies and the impact of maternal metabolism on pancreatic B-cell and somatic development in the offspring.

We have examined gravida with gestational diabetes mellitus (GDM), as defined by the National Diabetes Data Group (Diabetes 1979; 28:1039), for phenotypic and genotypic heterogeneity. Fasting plasma glucose (FPG) at diagnosis was used for further stratification of GDM according to putative metabolic severity into class A1 (FPG less than 105 mg/dl [N = 129]), class A2 (FPG 105-129 mg/dl [N = 47]), and class B1 (FPG greater than or equal to 130 mg/dl [N = 23]). All GDM classes tended to be older and heavier than consecutive gravida with documented normal glucose tolerance (controls, N = 148). Subdivision into "lean" and "obese" indicated that plasma immunoreactive insulin (IRI) was greater after overnight fast in the obese of all groups except B1. However, absolute increases in IRI above fasting levels in response to glucose during OGTT were significantly enhanced by obesity only in class A2 gravida. Adjustment for the effects of age and weight by covariate analysis indicated that the IRI response to glycemic stimulation is usually attenuated in all forms of GDM. Mean values for increases in IRI above fasting values during the first 15 min and IRI increments relative to the increases in plasma glucose throughout the 180-min OGTT were below control values in all GDM groups and progressively so, i.e., A1 less than A2 less than B1. The absolute insulinopenia was not invariable; a small number of gravida from all GDM groups displayed well-preserved IRI responses to oral glucose. Genotypic evaluation of the GDM population disclosed an increased occurrence of "markers" known to be associated with type I diabetes mellitus.(ABSTRACT TRUNCATED AT 250 WORDS)

Gestational diabetes mellitus. Correlations between the phenotypic and genotypic characteristics of the mother and abnormal glucose tolerance during the first year postpartum.

We evaluated glucose tolerance during the first year postpartum in 113 women with gestational diabetes mellitus (GDM) diagnosed according to the criteria of the First International Workshop-Conference on GDM and the National Diabetes Data Group. The high incidence of abnormal postpartum glucose tolerance (38% "diabetes mellitus" plus 19% "impaired glucose tolerance") was correlated with certain of the heterogeneous characteristics of the population at the time of antepartum diagnosis. Virtually all women with antepartum fasting plasma glucose (FPG) greater than or equal to 130 mg/dl (GDM class B1) remained abnormal postpartum (21/22 [95%]), which suggests that this group may include women with preexisting glucose intolerance unrecognized before pregnancy. In the remainder, those with FPG greater than or equal to 105-129 mg/dl (GDM class A2) were more likely to be abnormal postpartum than those with FPG less than 105 mg/dl (GDM class A1). Within the A1 and A2 groups, increasing maternal age, relative insulinopenia, and hyperglycemia at 2 h during antepartum OGTT were also associated with a greater likelihood of abnormal glucose tolerance postpartum. The presence of HLA-DR3 and/or -DR4 antigens was not predictive of the status of glucose tolerance during the first year postpartum, although the increased frequency of cytoplasmic islet cell antibodies in A2 and B1 subjects was associated with a high incidence of abnormal postpartum glucoregulation. The high incidence of abnormal postpartum glucose tolerance in all GDM classes makes a compelling case for careful, early, and continuing follow-up of all women with a diagnosis of GDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Biphasic changes in hemoglobin A1c concentrations during normal human pregnancy.

Analyses of hemoglobin A1c concentrations were performed throughout gestation in 377 nondiabetic women. We observed significant biphasic changes in hemoglobin A1c concentrations, with an initial gradual decline to a nadir level at 24 weeks, followed by a subsequent slow reascension to peak near term. All these changes fell within the usual range of normal values for hemoglobin A1c. Values for plasma glucose estimated 1 hour after a 50 gm oral glucose load in 1,756 normal gravid women showed similar biphasic excursions, with the nadir occurring 4 weeks earlier, i.e., at 20 weeks' gestation. We conclude that the small but significant changes in hemoglobin A1c during the course of normal gestation reflect, with an appropriate displacement in time, the biphasic alterations in mean blood sugar that characterize the sequential changes in glucoregulation during normal pregnancy.

The effect of gestational age on amniotic fluid glucose in pregnancy complicated by diabetes mellitus.

Amniotic fluid glucose was measured in 189 amniotic fluid samples from 117 well-controlled Class A to F diabetic pregnant women from 32 to 40 weeks' gestation. A simultaneous maternal plasma glucose level was determined at each amniocentesis. Samples were obtained with the mother in the fasting or nonfasting (3.8 hours after breakfast) state. Amniotic fluid glucose correlated significantly with simultaneous maternal glucose (r = 0.562; p = 0.001). A significant downward linear trend of mean amniotic fluid glucose with advancing gestational age was demonstrated (p less than 0.01). No trend of mean simultaneous maternal glucose with gestational age was seen. These results were not affected by maternal prandial status at the time of amniocentesis. It is concluded that amniotic fluid glucose decreases with advancing gestational age in well-controlled diabetic pregnant women independent of maternal glycemic levels. Studies of amniotic fluid glucose and/or its relationship to other metabolic hormones must take this into account.

Carbohydrate metabolism in pregnancy. XVII. Diurnal profiles of plasma glucose, insulin, free fatty acids, triglycerides, cholesterol, and individual amino acids in late normal pregnancy.

Diurnal profiles have been constructed for glucose, free fatty acids (FFA), triglycerides, cholesterol, and ten neutral amino acids in subjects with normal carbohydrate metabolism during late pregnancy and in age- and weight-matched nongravid women. Samples of blood were secured during a 24 hour period while the subjects were receiving a liquid formula diet (containing 2,110 kcal with 275 gm carbohydrate and 75 gm protein) in three equal feedings at 0800, 1300, and 1800 hours. Postprandial excursions for most nutrients, as well as plasma concentrations after overnight fast and before each meal, were significantly different in the pregnant subjects. The studies indicate that criteria of normalcy based on observations in nongravid women cannot be invoked assess fuel homeostasis in late pregnancy, and that separate criteria are necessary to evaluate nutrient regulation at this time.

Serial ultrasonography to assess evolving fetal macrosomia. Studies in 23 pregnant diabetic women.

Serial ultrasound estimates of fetal biparietal diameter and abdominal circumference were used as differential indices of intrauterine growth of insulin-insensitive and insulin-sensitive structures, respectively, in 23 White's classes A to C diabetic women. Biparietal diameter in all fetuses conformed to growth patterns for fetuses of nondiabetic mothers. However, two patterns were noted for abdominal circumference. Normal increases occurred in 13 fetuses; in the remaining ten, growth of abdominal circumference exceeded upper normal limits from weeks 28 to 32 of gestation onward. This latter group with putative "accelerated somatic growth" in utero had more immunoreactive insulin in amniotic fluid, weighed more at birth, and had more subcutaneous fat. Serial differential ultrasonography may be useful for detecting evolving macrosomia in diabetic pregnancies, and fetal insulin or insulin-like principles may contribute to the macrosomia.