Backbone dynamics of an alamethicin in methanol and aqueous detergent solution determined by heteronuclear (1)H- (15)N NMR spectroscopy.

The (15)N relaxation rates of the α-aminoisobutyric acid (Aib)-rich peptide alamethicin dissolved in methanol at 27°C and 5°C, and dissolved in aqueous sodium dodecylsulfate (SDS) at 27°C, were measured using inverse-detected one-and two-dimensional (1)H-(15)N NMR spectroscopy. Measurements of (15)N longitudinal (R(N)(N(z))) and transverse (R(N)(N(x,y))) relaxation rates and the {(1)H} (15)N nuclear Overhauser enhancement (NOE) at 11.7 Tesla were used to calculate (quasi-) spectral density values at 0, 50, and 450 MHz for the peptide in methanol and in SDS.

Preclinical evaluation of fluorine-18-labeled androgen receptor ligands in baboons.

Unlabelled: A noninvasive method for detecting and quantifying androgen receptors (AR) in metastatic prostate cancer may be helpful in choosing the method of treatment and in better understanding the pathophysiology of this disease. Nine previously synthesized fluorinated androgens exhibited high affinity binding to AR and showed AR-mediated uptake in the ventral and dorsal prostate of the rat. Further evaluation of these agents for PET imaging is needed since sex hormone binding globulin (SHBG), a glycoprotein which binds androgens with high affinity, is absent in rat blood but is present at high levels in the blood of primates.

Treatment of diabetes by xenogeneic islets without immunosuppression. Use of a vascularized bioartificial pancreas.

Tight glycemic control by intensive insulin therapy effectively delays the onset and slows the progression of diabetic complications but is associated with frequent dose adjustments and a high incidence of hypoglycemia. Successful pancreas transplantation corrects abnormal glucose metabolism but subjects patients to morbidity and mortality associated with chronic immunosuppression. A vascularized artificial pancreas device containing pancreatic islets is designed to provide glycemic control without immunosuppression.

Issues in health policy for indigenous peoples in Canada.

This paper provides a preliminary report on the work of the Canadian Royal Commission on Aboriginal Peoples. This commission has spent the past four years undertaking a comprehensive review of all matters pertaining to indigenous people in Canada, and will publish a final report in late 1995 or early 1996. The paper provides an overview of health policy issues examined by the commission.

A pilot study of the effect of low level exposure to mercury on the health of dental surgeons.

Objectives: This project was conducted to examine whether the computerised analysis of psychomotor responses available from Cognitive Drug Research is appropriate for measuring an effect of low level exposure to mercury in dentists.

Methods: A computerised battery of psychomotor tests was given to two groups of dentists (older dentists and trainees) and to two age matched control groups. As well as the psychomotor tests, volunteers were required to complete a questionnaire to identify potential influences on psychomotor performance and to provide a sample for analysis of urinary mercury.

Induction by herpes simplex virus of free and heteromeric forms of E2F transcription factor.

We have determined that HSV causes rapid and large increases in cell-cycle-regulated free E2F and S-phase p107/E2F DNA binding activities in asynchronous cultures of C33A cells. Induction occurred by 4 hr postinfection and coincided with the appearance of viral encoded immediate-early and delayed-early proteins, i.e.

Injuries from falls on playgrounds. Effects of day care center regulation and enforcement.

Objectives: To measure the incidence of playground fall injuries among children attending licensed US day care centers and to evaluate how injury incidence varies with center characteristics and with the regulatory and enforcement climate in which centers operate.

Design: Telephone surveys of directors of day care centers and enforcement agencies and review of written day care regulations.

Setting: Probability sample of licensed day care centers in 50 states and the District of Columbia.

The predictive value of posterior pole vessels in retinopathy of prematurity.

Dilation and tortuosity of the posterior pole vessels "(plus disease)" is a sign of poor prognosis and may be associated with threshold or prethreshold retinopathy of prematurity (ROP). We have found that normal posterior pole vessels are a reliable marker for the absence of stage 3 ROP. One hundred thirty-two consecutive premature infants weighing less than 1600 g at birth underwent ROP examinations between 32 and 40 weeks' postconceptional age.

Plasma lipids in two indigenous Arctic populations with low risk for cardiovascular diseases.

The distribution of plasma lipids and their sociodemographic and metabolic correlates were investigated in two Arctic indigenous populations based on two health surveys conducted during 1990-1991 among adults in eight Inuit communities in the Keewatin region of the Northwest Territories, Canada (n = 387), and in four communities in the Chukotka region in the Russian Far North (n = 362). For comparison, data from the Canadian Heart Health Survey were used. The age-sex-specific mean total and low-density lipoprotein (LDL)-cholesterol levels among Inuit in northern Canada either do not differ significantly from the Canadian national population, or, in the case of younger Inuit women, are higher than in Canadians.

The population survey as a tool for assessing family health in the Keewatin region, NWT, Canada.

The population survey is an important tool in community health assessment, including the physical and psychological aspects of family health. It provides data on health status and health determinants not available from vital statistics and health service utilization. The Keewatin Health Assessment Study (KHAS), which was designed in collaboration with the Keewatin Regional Health Board (KRHB), surveyed a representative sample of the predominantly Inuit population in 8 communities in the central Canadian Arctic.

Inactivation of lysosomal proteases by oxidized low density lipoprotein is partially responsible for its poor degradation by mouse peritoneal macrophages.

Deficient processing of apo B in oxidized LDL (ox-LDL) by macrophage lysosomal proteases has been documented and attributed to modifications in apo B. We have investigated whether direct inactivation of lysosomal proteases by ox-LDL could also be responsible for this deficient degradation. When mouse peritoneal macrophages (MPM) were preincubated for 21 h at 37 degrees C with ox-LDL, LDL, or vortex-aggregated LDL, only ox-LDL inhibited the subsequent degradation of 125I-labeled forms of the above lipoproteins.

Study groups: are they effective in preparing students for NCLEX-RN?

The effectiveness of faculty-directed study groups as an intervention to prepare nurse candidates for NCLEX-RN was evaluated. The NCLEX-RN performance of a baccalaureate class who had participated in study groups was compared to the performance of a prior class who had not participated in study groups. Academic subgroups within the classes were compared to determine if study groups were equally effective across levels of academic achievement.

The compliance of licensed US child care centers with national health and safety performance standards.

The American Public Health Association and the American Academy of Pediatrics recently published health and safety guidelines for child care centers. A survey was conducted to determine the extent to which practices in US child care centers are reflective of these guidelines. Compliance with 16 guidelines ranged from 19.

Progestin radiopharmaceuticals labeled with technetium and rhenium: synthesis, binding affinity, and in vivo distribution of a new progestin N2S2-metal conjugate.

We have prepared and evaluated three metal conjugates of a progestin-monoamine-monoamide (MAMA') bisthiol chelate system. These conjugates of rhenium and technetium-99 and -99m, are structural analogs of the bisamino-bisthiol (BAT) conjugates we have described recently, but the MAMA' chelate, being more polar than the BAT system, gives a conjugate that is much less lipophilic, having an octanol-water partition coefficient that is nearly 80-fold lower. In competitive binding assays, the Re- and 99Tc-MAMA'-progestin conjugates bind to the progesterone receptor with affinities greater than that of progesterone itself, and in a direct binding assay, the equilibrium dissociation constant (Kd) of the 99mTc-MAMA' conjugate was 0.

Thermodynamics of transfer of indocarbocyanines from gel to fluid phases of phospholipid bilayers.

Application of the regular solution model to thermal transition data obtained by differential scanning calorimetry has allowed the determination of partition coefficients, Kp, and the thermodynamics of transfer of a series of indocarbocyanine solutes between the gel and fluid phases of phospholipid bilayers. The indocarbocyanines with alkyl chain lengths of 12 to 22 carbons were partitioned between dipalmitoyl- and distearoylphosphatidylcholine phases at the transition temperatures of the gel-liquid-crystal phase transition. The results indicate that as the alkyl chain length of the solute nears that of the acyl chains of the bilayer lipid, the free energy of transfer from gel to fluid is least negative, and the enthalpy of transfer is most positive.

Homodimeric and heterodimeric bis(amino thiol) oxometal complexes with rhenium(V) and technetium(V). Control of heterodimeric complex formation and an approach to metal complexes that mimic steroid hormones.

We have investigated the possibility of preparing complexes of rhenium and technetium whose shape resembles that of ligands for steroid receptors. The general structure of N2S2 complexes of oxorhenium(V) and oxotechnetium(V) is such that they could replace the BC ring system of steroid, thereby generating a metal complex system with considerable size and shape similarity to a steroid. Such a metal-integrated steroid-shaped complex can be constructed as a heterodimer of two different amino thiols; complexes of rhenium and technetium with such heterodimeric bis-bidentate structure have not been systematically studied.

An X-ray crystallographic study of the nonsteroidal contraceptive agent centchroman.

We have determined an X-ray crystal structure for the N-methyl iodide derivative of the nonsteroidal contraceptive centchroman. The pendant aromatic substituents on C-3 and C-4 of the chroman system are nearly perpendicular to the plane of the chroman system, an orientation expected in such a chroman, but perturbed to some degree by the gem dimethyl substituents at C-2. Structural superposition with other nonsteroidal antiestrogens, tamoxifen and nafoxidine, shows a similar disposition of the tertiary amine side chains responsible for antagonist activity.

A nationwide study of the risk of injury associated with day care center attendance.

Objective: Because an increasing proportion of US children spends time in day care center environments, a national estimate of injury risks in day care centers is needed.

Methods: We interviewed directors of 1797 day care centers from every state and the District of Columbia from October to December 1990 and analyzed medically attended injuries and center characteristics reported by the directors.

Results: The centers were attended by 138,404 children.

Lp(a) and premature mortality during chronic hemodialysis treatment.

Lipoprotein(a) levels are approximately three to four times higher in patients with end-stage renal disease (ESRD) when compared to controls with normal renal function (H.J. Parra, H.