Influence of twenty-five per cent human serum albumin on total and ionized calcium concentrations in vivo

BACKGROUND: A inverse correlation has been found between changes in ionized calcium concentrations and the addition of albumin in vitro, which may explain adverse cardiovascular effects attributed to exogenous albumin in vivo. The purpose of this investigation was to determine the interaction (if any) between exogenous 25% albumin administration (100 ml given over < 30 min) and calcium concentrations in patients, all but one of whom were in an intensive care unit. RESULTS: There were no significant differences in the ionized calcium concentrations obtained before, at the end and 6 h after the administration of albumin (1.09 +/- 0.23, 1.06 +/- 0.22, 1.06 +/- 0.21 mmol/l, respectively). Similarly, there were no significant differences in the total calcium concentrations between these same time periods (2.03 +/- 0.18, 2.05 +/- 0.20, 2.08 +/- 0.23 mmol/l, respectively). CONCLUSIONS: In patients receiving infusions of 25% albumin, it appears that circulating calcium concentrations are well regulated by homeostatic mechanisms. Albumin infusions had no effect on calcium concentrations, although it is possible that temporary changes of questionable clinical importance may have occurred between measurement periods.     

Adaptation and implementation of local maternity dashboards in a Zimbabwean hospital to drive clinical improvement

Problem

The Commission on Information and Accountability for Women''s and Children''s Health of the World Health Organization (WHO) reported that national health outcome data were often of questionable quality and “not timely enough for practical use by health planners and administrators”. Delayed reporting of poor-quality data limits the ability of front-line staff to identify problems rapidly and make improvements.

Approach

Clinical “dashboards” based on locally available data offer a way of providing accurate and timely information. A dashboard is a simple computerized tool that presents a health facility’s clinical data graphically using a traffic-light coding system to alert front-line staff about changes in the frequency of clinical outcomes. It provides rapid feedback on local outcomes in an accessible form and enables problems to be detected early. Until now, dashboards have been used only in high-resource settings.

Local setting

An overview maternity dashboard and a maternal mortality dashboard were designed for, and introduced at, a public hospital in Zimbabwe. A midwife at the hospital was trained to collect and input data monthly.

Relevant changes

Implementation of the maternity dashboards was feasible and 28 months of clinical outcome data were summarized using common computer software. Presentation of these data to staff led to the rapid identification of adverse trends in outcomes and to suggestions for actions to improve health-care quality.

Lessons learnt

Implementation of maternity dashboards was feasible in a low-resource setting and resulted in actions that improved health-care quality locally. Active participation of hospital management and midwifery staff was crucial to their success.     

Implementation of a prospective pregnancy registry for antiretroviral based HIV prevention trials

Background: Safety data on pregnancy and fetal outcomes among women in HIV prevention trials are urgently needed to inform use of effective antiretroviral agents for HIV prevention. We describe an effective, efficient, and novel method to prospectively collect perinatal safety data concurrent with on-going parent clinical trials.

Methods: The Microbicide Trials Network (MTN)-016 study is a multinational prospective pregnancy exposure registry designed to capture pregnancy and neonatal outcomes. Studies currently contributing data to this registry included phase I and II safety trials with planned exposures to candidate HIV prevention agents, as well as phase IIB and III efficacy trials capturing data on pregnancy and infant outcomes following inadvertent fetal exposure during study participation.

Results: To date, participants from two phase I studies and two effectiveness trials have participated in MTN-016, resulting in 420 pregnant women and 381 infants enrolled. Infant retention has been high, with 329 of 381 (86%) infants completing the 12-month follow-up visit.

Conclusion: In a research setting context, it is feasible to establish and implement a prospective, multinational HIV chemoprophylaxis pregnancy registry that will generate pregnancy exposure data in a robust fashion.     

A decade of spore-forming bacterial infections among European injecting drug users: pronounced regional variation

The recent anthrax outbreak among injecting drug users (IDUs) in Europe has highlighted an ongoing problem with severe illness resulting from spore-forming bacteria in IDUs. We collated the numbers of cases of 4 bacterial illnesses (botulism, tetanus, Clostridium novyi, and anthrax) in European IDUs for 2000 to 2009 and calculated population rates. Six countries reported 367 cases; rates varied from 0.03 to 7.54 per million people. Most cases (92%) were reported from 3 neighboring countries: Ireland, Norway, and the United Kingdom. This geographic variation needs investigation.     

Effects of oxytocin on steroidogenesis by bovine theca and granulosa cells

Oxytocin (OT) is secreted during the final stages of bovine follicular development. To test OT's potential role as a regulator of follicular steroidogenesis, theca and granulosa cells were isolated from bovine preovulatory follicles 48 h after initiation of luteolysis with prostaglandin F2 alpha, and cultured with graded doses of OT (0, 0.5, 5, 50, and 500 mIU/ml). Granulosa cells were cultured with testosterone (0.5 microM) in either defined medium or medium containing 10% fetal bovine serum in the presence or absence of FSH (300 ng/ml); medium was collected and replaced daily for 5 days. In defined medium, oxytocin alone significantly increased progesterone production by granulosa cells (P less than 0.001) in a dose-dependent manner; over 5 days, doses of 0.5, 5, 50, and 500 mIU/ml OT caused 1.7-, 2.0-, 2.2-, and 2.6-fold increases. FSH enhanced progesterone 5-fold, but no dose of OT increased progesterone in the presence of FSH. OT also elevated progesterone in serum-containing medium (P less than 0.005), but the magnitude of its effects was lower (1.07-, 1.1-, 1.2-, and 1.4-fold increases with 0.5, 5, 50, and 500 mIU/ml OT). OT had little effect on estradiol secretion by granulosa cells cultured with or without FSH. To test the specificity of OT's effects on progesterone production by granulosa cells, granulosa cells were treated with graded doses of an OT antagonist (0, 1, 10, 100, and 1000 ng/ml) in the presence or absence of OT (5 and 50 mIU/ml). Progesterone production by granulosa cells in the presence of the antagonist alone was similar to production in control cultures. The stimulatory effects of 5 and 50 mIU OT were completely abolished in the presence of 100 or 1000 ng antagonist, respectively (P less than 0.01). Preparations of theca interna were cultured in defined medium with graded doses of OT (0, 0.5, 5, 50, and 500 mIU/ml) in the presence or absence of LH (300 ng/ml), with collection and replacement of medium at 3, 6, 12, 24, 48, and 72 h. LH alone increased both progesterone (12-fold) and androstenedione (4-fold) production over controls. However, no dose of OT significantly affected either progesterone or androstenedione production. These results show that OT stimulates progesterone production by granulosa cells, and thus, suggest that OT regulates steroidogenesis in bovine granulosa cells in vivo.     

自动微生物鉴定药敏分析系统

介绍2000型自动微生物药敏分析系统的原理、特点及应用前景。     

Progesterone secretion by granulosa cells from rats with four- or five-day estrous cycles: the development of responses to follicle-stimulating hormone, luteinizing hormone, and testosterone

Changes in granulosa cell sensitivity and responsiveness to gonadotropins during the rat estrous cycle were studied by measuring progesterone (P) secretion in vitro in response to treatment with increasing doses of LH or FSH (0, 0.1, 1, 10, 100 ng/ml). The effect of testosterone [(T); 0.5 microM] on response to gonadotropins was also examined. Granulosa cells were isolated from the largest ovarian follicles of rats with 4- and 5-day estrous cycles at 0800 h, 1400 h, and 2000 h on proestrus and on the preceding day of diestrus at 1200 h and 2000 h. In rats with 5-day cycles, granulosa cells were also obtained at 1200 h on the first day of diestrus. Fifty percent maximal P production and 50% effective dose (ED50-dose of gonadotropin which elicited 50% maximal P production) were calculated from dose-response curves for LH and FSH and were used as measures of responsivity and sensitivity to gonadotropins, respectively. Basal P secretion and 50% maximal P secretion increased progressively as cells were isolated at later stages of follicular growth in both 4- and 5-day cycles. In cells from 5-day rats, however, basal and gonadotropin-stimulated P secretion were higher on the second day of diestrus than in cells from 4-day rats. By proestrus responsiveness was equal. Granulosa cell sensitivity to FSH was constant during 4- and 5-day cycles, as indicated by a lack of change in the ED50. Granulosa cell sensitivity to LH was lower than sensitivity to FSH on diestrus of both 4- and 5-day cycles. However, by the morning of proestrus sensitivity to LH increased and was similar to that for FSH. T increased basal P production only slightly, but synergized with both LH and FSH to stimulate 2-fold increases in 50% maximal P production by granulosa cells isolated at all times except 2000 h on proestrus, after the endogenous LH surge. T had no effect on the sensitivity (ED50) of granulosa cells to LH or FSH. In summary, granulosa cell responsiveness to LH and FSH increased in parallel during the final stages of follicular growth, but increased sensitivity was noted only for LH. The development of granulosa cell capacity to secrete P appears to be more advanced in 5-day rats than in 4-day rats relative to the next estrus. Because T synergized with LH and FSH to increase P secretion without altering sensitivity to gonadotropins, it probably acts at a site distal to gonadotropin receptors.     

Osteocalcin as an index of osteoblast function during and after ovine pregnancy

Fetal and neonatal calcium requirements impose heavy demands on maternal bone and mineral homeostasis. The functional response of maternal osteoblasts to this stress is poorly understood. Therefore, plasma osteocalcin (OC) levels were measured by homologous RIA in age-matched nonpregnant, pregnant, and postpartum ewes to evaluate osteoblast function. In pregnant ewes from day 35 of gestation to term, the plasma OC level was suppressed to 8.2 +/- 0.5 micrograms/liter (mean +/- SEM; n = 36) compared with age-matched nonpregnant ewes (18.3 +/- 1.1 micrograms/liter; n = 39; P less than 0.0005). Plasma OC rose to the nonpregnant value by day 20 postpartum and was elevated above this level for the following 40 days (e.g. 44.0 +/- 5.0 micrograms/liter at 48-53 days; P less than 0.0005). The timing of changes in plasma OC levels and weaning did not correlate. The validity of plasma OC measurement as a marker of osteoblast function was assessed by determining the OC plasma production and clearance rates using an [125I]ovine OC infusion method. The OC plasma production rates in matched controls (n = 6), pregnant (n = 9), and 48-53-day postpartum sheep (n = 7) were 1.5 +/- 0.2, 0.5 +/- 0.04 (P less than 0.001 vs. control), and 3.6 +/- 0.6 mg/day (P less than 0.005 vs. pregnant sheep), respectively. In one ewe studied longitudinally, the OC plasma production rate increased by 15 days after parturition and achieved a 10-fold elevation at 49 days postpartum. The OC plasma clearance rate (3.3 +/- 0.3 liters/h) was the same in control, pregnant, and postpartum ewes. It is concluded that 1) changes in plasma OC levels during and after ovine pregnancy reflected changes in OC production, 2) plasma OC measurements are likely to be a useful index of osteoblast function in pregnancy, and 3) osteoblast function appears to be depressed during ovine pregnancy and enhanced markedly in the interval 20-60 days postpartum. The relationship between osteoblast function, as indicated by OC production, and bone formation remains to be clarified.     

Superovulation in cattle: effects of purity of FSH preparation on follicular characteristics in vivo.

When cattle were superovulated with an FSH preparation containing no detectable LH (FSH-W), more viable embryos were recovered as compared with a standard preparation containing LH (FSH-P), with no change in the total number of ova + embryos recovered (Donaldson et al., 1986). To determine the basis for the increased embryo viability, we compared numbers of developing follicles and concentrations of estradiol in their follicular fluid at two times during the course of superovulatory treatment with FSH-P vs. FSH-W. Holstein heifers (n = 10/group) were injected with 3.5 mg of FSH-P or FSH-W twice daily beginning on Day 9 of the estrous cycle. Animals were ovariectomized either 48 h (Group 1) or 72 h (Group 2) after the initiation of treatment; heifers in Group 2 were also given a luteolytic injection of prostaglandin F2 alpha 24 h before ovariectomy. All follicles greater than S mm in diameter were dissected from the ovaries and follicular fluid was aspirated and stored frozen. Heifers injected with FSH-W had more follicles greater than 5 mm than heifers treated with FSH-P (21 + 4 vs. 11 + 3 in Group 1 and 28 + 5 vs. 20 +/- 5 in Group 2, respectively; p less than 0.05) and a significantly greater percentage of follicles from FSH-W animals were healthy (estrogen-active; 99 vs. 85% in Group 1 and 98 vs. 89% in Group 2, respectively; p less than 0.025). Estradiol concentrations in follicular fluid were more strongly correlated (p less than 0.001) with follicular size when heifers were treated with FSH-P vs. FSH-W.(ABSTRACT TRUNCATED AT 250 WORDS)