Magnetic trapping of SH radicals.

Magnetic trapping of SH radicals, produced via the photostop technique, has been demonstrated. H2S in a skimmed, supersonic molecular beam was photodissociated at 212.8 nm to produce SH inside a 330 mK deep static magnetic trap. The molecular-beam speed was controlled by the mixing ratio of H2S in Kr to match the recoil velocity of the SH photofragments such that some SH radicals were produced with near-zero laboratory-frame velocity. The density of SH radicals in the 2Π3/2, v = 0, J = 3/2 state was followed by (2 + 1) REMPI over seven orders of magnitude of signal intensity. 5 ms after photodissociation, SH radicals moving faster than the capture velocity of 13 m s-1 had left the trap. The 1/e trap lifetime of the remaining SH radicals was 40 ± 10 ms at an estimated density of 5 × 104 molecules per cm3. Photostop offers a simple and direct way to accumulate absolute ground state molecules in a variety of traps.

The Effects of Sertraline on Fathead Minnow (Pimephales promelas) Growth and Steroidogenesis.

The purpose of this study was to evaluate the steroidogenic effects of sertraline, a popular selective serotonin reuptake inhibitor, on larval fathead minnow (FHM; Pimephales promelas) and adult FHM. Larvae were exposed to 0.1, 1, and 10 µg/L sertraline for 28 days and analyzed for differential mRNA expression of 11ß-hydroxysteroid dehydrogenase (11ß-HSD), 20ß-hydroxysteroid dehydrogenase (20ß-HSD), aromatase (CYP19a), nuclear thyroid receptor alpha (TRα), and normalized to RP-L8. Adult FHM were exposed to 3 or 10 µg/L sertraline for 7 days and analyzed for differential expression of the same genes with the addition of thyroid receptor beta (TRß). Larval FHM exposed to 0.1 µg/L had a significant upregulation of both 20ß-HSD and TRα while adult FHM exposed to 10 µg/L had a significant upregulation of 11ß-HSD expression in brain tissue. The significance of these findings with respect to survival, growth and reproduction are currently unknown, but represent areas for future research.

A "Diabetes Acute Care Day" for medical students increases their knowledge and confidence of diabetes care: a pilot study.

BACKGROUND: Evidence suggests that junior doctors lack the confidence and skills to manage acute/inpatient diabetes. We investigated the impact of the introduction of a "Diabetes Acute Care Day" on undergraduate medical students' knowledge and confidence in acute/inpatient diabetes. METHODS: Participants attended four short lectures on the basics of diabetes, diabetic emergencies, inpatient diabetes management and peri-operative/procedure care followed by case-based learning tutorials on diabetic ketoacidosis (DKA), hyperosmolar hyperglycaemic state (HHS) and hypoglycaemia using capillary blood glucose charts to interpret and practice subsequent insulin prescription and adjustment. Participants were asked to complete multiple-choice questions and confidence questionnaires using a visual analogue score pre and post participation. RESULTS: One hundred forty-four students completed the pre-course survey and 196 completed the post-course survey. Mean confidence using a visual analogue score increased in all areas with a mean at baseline of 46.9 mm rising to 71.2 mm post-participation (p < 0.001). The largest increases were in the management of HHS, patients on subcutaneous and intravenous insulin and perioperative/procedure care. The mean mark obtained in the pre-test multiple choice questions (MCQs) was 2.72 (27.2 %) and increased to 4.74 (47.4 %) on the post-score MCQs (p < 0.001). 56.9 % of participants answered all 10 pre-test MCQs with the mean number of questions answered = 4.71 rising to 82.0 % of students answered all ten questions and the mean number of questions answered = 9.56 in the post-test MCQs. CONCLUSIONS: An intensive "Diabetes Acute Care Day" consisting of themed live lectures and case-based learning tutorials is an effective way to increase medical students' knowledge and confidence in acute/inpatient diabetes. Further development and evaluation of this educational intervention is required to assess the impact of on patient care in the clinical setting post graduation.

Endothelial FOS expression and pre-eclampsia.

OBJECTIVE: To study gene expression profiles in human endothelial cells incubated with plasma from women who developed pre-eclampsia and women with normotensive pregnancies. DESIGN: A case-control study. SETTING: A longitudinal nested case-control study within three maternity units. POPULATION: A mixed obstetric population attending maternity hospitals in Glasgow. METHODS: Plasma was obtained at both 16 and 28 weeks of gestation from 12 women: six women subsequently developed pre-eclampsia (cases) and six women, matched for age, body mass index (BMI) and parity, remained normotensive (controls). Human umbilical vein endothelial cells (HUVECs) were incubated with plasma for 24 hour before RNA isolation. MAIN OUTCOME MEASURES: Gene expression profiles were compared between the two gestational time points using Illumina(®) HumanHT-12 v4 Expression BeadChips. Differential mRNA expression observed in microarray experiments were validated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), and gene networks were analysed using Ingenuity(®) pathway analysis. RESULTS: There was a significant difference in the expression of 25 genes following incubation with plasma from controls, and an increase in the expression of 11 genes following incubation with plasma from cases, with no overlap between the two groups (false discovery rate, FDR < 0.05). There was a 3.74-fold (FDR < 0.001) increase in the expression of the c-Fos gene (FOS) when HUVECs were incubated with control plasma from 16 and 28 weeks of gestation, with no significant difference between the two time points with plasma from cases. Similar findings for FOS were obtained by qRT-PCR. CONCLUSIONS: Plasma from women who subsequently develop pre-eclampsia appears to contain factors that lead to the dysregulation of FOS in endothelial cells during pregnancy. Reduced expression of c-Fos may lead to impaired vasculogenesis, and thereby contribute to the development of pre-eclampsia.

Production of cold bromine atoms at zero mean velocity by photodissociation.

The production of a translationally cold (T < 1 K) sample of bromine atoms with estimated densities of up to 10(8) cm(-3) using photodissociation is presented. A molecular beam of Br(2) seeded in Kr is photodissociated into Br + Br* fragments, and the velocity distribution of the atomic fragments is determined using (2 + 1) REMPI and velocity map ion imaging. By recording images with varying delay times between the dissociation and probe lasers, we investigate the length of time after dissociation for which atoms remain in the laser focus, and determine the velocity spread of those atoms. By careful selection of the photolysis energy, it is found that a fraction of the atoms can be detected for delay times in excess of 100 µs. These are atoms for which the fragment recoil velocity vector is directly opposed and equal in magnitude to the parent beam velocity leading to a resultant lab frame velocity of approximately zero. The FWHM velocity spreads of detected atoms along the beam axis after 100 µs are less than 5 ms(-1), corresponding to temperatures in the milliKelvin range, opening the possibility that this technique could be utilized as a slow Br atom source.

A region of adenylyl cyclase 2 critical for regulation by G protein beta gamma subunits.

Receptor-mediated activation of heterotrimeric guanine nucleotide-binding proteins (G proteins) results in the dissociation of alpha from beta gamma subunits, thereby allowing both to regulate effectors. Little is known about the regions of effectors required for recognition of G beta gamma. A peptide encoding residues 956 to 982 of adenylyl cyclase 2 specifically blocked G beta gamma stimulation of adenylyl cyclase 2, phospholipase C-beta 3, potassium channels, and beta-adrenergic receptor kinase as well as inhibition of calmodulin-stimulated adenylyl cyclases, but had no effect on interactions between G beta gamma and G alpha o. Substitutions in this peptide identified a functionally important motif, Gln-X-X-Glu-Arg, that is also conserved in regions of potassium channels and beta-adrenergic receptor kinases that participate in G beta gamma interactions. Thus, the region defined by residues 956 to 982 of adenylyl cyclase 2 may contain determinants important for receiving signals from G beta gamma.

A study of lactate dehydrogenase levels and turnover rates during postnatal development in the rat.

Specific radioimmunoassays for lactate dehydrogenase A and B subunits have been employed to quantify cellular contents of these proteins more precisely than hitherto possible and to monitor changes during postnatal development. Liver, skeletal muscle, heart muscle and kidney cortex all demonstrated alterations in cellular levels of lactate dehydrogenase subunits over the first 56 days of life, the particular pattern being specific to each tissue. Studies on the turnover of lactate dehydrogenase in vivo and in vitro indicated that the developmental changes in total lactate dehydrogenase content in liver and kidney were regulated at some point(s) during both the biosynthesis and the degradation of the proteins.

A 43 kDa form of the GTP-binding protein Gi3 in human erythrocytes.

Purified preparations of human erythrocyte G-proteins contain a 43 kDa pertussis toxin substrate which appears to be the alpha-subunit of a heterotrimeric GTP-binding protein. The 43 kDa protein is recognized by antisera that are sequence-specific for peptides encoding a sequence common to all 39-53 kDa G-protein alpha-subunits. G alpha o-specific antiserum did not recognize 43 or 40-41 kDa alpha-subunits. AS/6, which recognizes the alpha i proteins, recognized 43 kDa as well as 40-41 kDa proteins. Of the three antisera specific for individual members of the alpha i family, only the Gi3-specific antiserum recognized the 43 kDa erythrocyte G-protein. However, 40-41 kDa forms of all three alpha is are present. These observations indicate that human erythrocytes contain a novel 43 kDa form of Gi3.

A decade of improvement in areas of chronic disease. Where do we go from here?

The last decade has seen significant progress in reduction of mortality rates from many chronic diseases on both a state and national level. Moreover, in general, Wisconsin has achieved levels below the United States for mortality. However, as suggested by Figures 1 and 2, preventive efforts in stroke and prostate cancer should become high priorities in this state. Additionally, it will be important to monitor the stabilization of death rates due to diabetes. Turning Point, anti-tobacco efforts by the Tobacco Control Board and the Thomas T. Melvin Program, and the upcoming Minority Health Report should reveal additional areas for DHFS and its statewide partners to address in the arena of chronic disease. Programs such as the Wisconsin Diabetes Control Program and the Wisconsin Well Woman Program will also continue to contribute significantly to other community and clinical efforts to control chronic diseases.

Cigarette smoking in Wisconsin: the influence of race, ethnicity, and socioeconomics.

A disparate burden of cigarette use has been demonstrated among demographic subgroups both in the United States and Wisconsin. We examined patterns of adult current smoking prevalence in Wisconsin by race, Hispanic ethnicity, household income, and education to assess whether differences exist among these subgroups. This analysis revealed a strong graded relationship between household income, education, and smoking prevalence, consistent among non-Hispanic whites and blacks, though not Hispanics. Respondents with less than a high school education had significantly higher smoking prevalence rates (41%) than those with a college degree or more (13%). Smoking prevalence rates did not significantly differ between the race and ethnicity subgroups overall, or by gender and education, although they differed in some age and income subgroups. Possible explanations for the socioeconomic gradient include differences in tobacco product marketing practices, indoor workplace smoking policies, and access to health information, resources, and consistent, high-quality health care.

Pulse wave analysis for the prediction of preeclampsia.

Preeclampsia is associated with a number of changes to maternal vascular function. Assessment of arterial stiffness using pulse wave analysis (PWA) has been proposed as a means of predicting preeclampsia before the onset of clinically detectable disease. One hundred and eighty women with 2 risk factors for preeclampsia were examined at gestational weeks 16 and 28, of whom 17 (9.4%) developed preeclampsia. To study the effects of pregnancy itself women were also examined at 6-9 months post-natally; an additional 30 healthy non-pregnant women were also examined. PWA was performed using SphygmoCor; augmentation index (AIx), a marker of arterial wave reflection, was also measured using EndoPAT-2000. Women who developed preeclampsia were more likely to be overweight and had a higher brachial and central diastolic BP at gestational week 16 than those who remained normotensive. There was no difference in any parameter of arterial wave reflection between non-pregnant and pregnant women, nor between those who developed preeclampsia and those who remained normotensive, when examined at weeks 16 and 28 or post-natally. In this cohort of women with risk factors for preeclampsia, PWA did not provide additional information beyond brachial blood pressure and maternal risk factor profile about the risk of future development of preeclampsia.

Proteomics in hypertension.

Proteomics, the study of the proteins making up the proteome, has emerged in recent years as an important tool in several different fields of medical research for early disease detection, for assessment of response to treatment and for unravelling underlying pathophysiological mechanisms. Although the majority of patients with hypertension are treated in a similar manner, the causes underlying the condition are diverse, and often poorly understood. Genetic studies have implicated several different candidate genes, but it may be that examination of the 'downstream' products of genes, the proteins, will help to improve understanding of the link between the environmental and genetic effects that contribute towards development of hypertension. Proteomic studies can be performed quickly and reliably on several different sample types including plasma and urine, requiring minimal pre-test preparation. In this review, we will compare the different analytical platforms and technical issues involved in proteomic analysis. We will discuss existing studies of proteomics in hypertension, as well as related conditions such as renal disease, pre-eclampsia and coronary artery disease. We will also explore potential future applications of proteomics-based research, which may ultimately lead to improved population screening, monitoring of therapy and early detection of target organ damage.

Purification and radioimmunoassay of rat lactate dehydrogenase A and B subunits.

We have developed procedures for purifying lactate dehydrogenase isoenzymes from rat tissues that involve two affinity-chromatography steps and that facilitate the isolation of milligram quantities of highly purified proteins within 2--3 days. Antibodies raised against pure A and B subunits in rabbits and hens were used in radioimmunoassays and showed negligible cross-reactivity with heterologous subunits. The radioimmunoassays provide a sensitive method for measuring nanogram amounts of A-subunit and B-subunit polypeptides in tissue homogenates and were employed to characterize the enzyme purification procedures.

Fractionation of platelets according to size: functional and biochemical characteristics.

The functional and biochemical heterogeneity of platelets has been studied using graded differential centrifugation to fractionate human platelets according to size while maintaining their morphological and functional integrity as indicated by scanning electron microscopy and content of beta-thromboglobulin. Aggregation kinetics were studied by both optical and quenched-flow methods involving single-particle counting. Large platelets were significantly more sensitive to ADP, but aggregated less rapidly than small platelets. Thrombin exerted a similar influence. Large platelets were also enriched in surface sialic acid and sulfhydryl groups and in internal glycogen, ATP, ADP, calcium, cyclic AMP, malonaldehyde, and succinate cytochrome c reductase when compared to small platelets, even when normalized per unit volume. ADP caused a more rapid breakdown of cyclic AMP in small platelets. Potential aging relationships were tested by isotope studies in rats. 75Se-selenomethionine was incorporated in vivo at a similar rate into all fractions. Large platelets labeled with 51Cr disappeared from circulation linearly and had a longer mean lifespan than small platelets, which disappeared exponentially. This behavior supports independent aging of platelet populations of differing size. The data suggest a distinct heterogeneity in platelet function and fate, which could derive from protection of large platelets against excessive activation by Ca2+-regulated events.

Thrombin causes subsecond changes in protein phosphorylation of platelets.

We have developed a general quenched-flow approach to study platelet function as early as 0.3 seconds after stimulation. Phosphorylation of 20- and 40-kd proteins has been analyzed during the first five seconds of platelet response to thrombin from 0.1 to 5.0 U/mL and compared with the progress of aggregation and serotonin secretion. The onset time for aggregation and phosphorylation of both proteins was less than one second, although with lowest (less than 0.5 U/mL) thrombin levels, a lag of up to 0.6 seconds occurred before 40K phosphorylation increased. The thrombin sensitivity of aggregation and 20K phosphorylation was approximately twice that of 40K phosphorylation, with Ka values of 0.51 and 0.53 v 1.10 U/mL, respectively. External calcium was necessary for maximal 20K phosphorylation, since EDTA inhibited this by 30%. The 40K phosphorylation was not affected by EDTA. Platelet activation by thrombin thus induced biochemical changes well before one second. The quenched-flow approach may help to reveal relationships between phospholipase activation, calcium fluxes, and protein phosphorylation during these early periods of platelet function.