The Tbx20-TLE interaction is essential for the maintenance of the second heart field

T-box transcription factor 20 (Tbx20) plays a multifaceted role in cardiac morphogenesis and controls a broad gene regulatory network. However, the mechanism by which Tbx20 activates and represses target genes in a tissue-specific and temporal manner remains unclear. Studies show that Tbx20 directly interacts with the Transducin-like Enhancer of Split (TLE) family of proteins to mediate transcriptional repression. However, a function for the Tbx20-TLE transcriptional repression complex during heart development has yet to be established. We created a mouse model with a two amino acid substitution in the Tbx20 EH1 domain, thereby disrupting the Tbx20-TLE interaction. Disruption of this interaction impaired crucial morphogenic events, including cardiac looping and chamber formation. Transcriptional profiling of Tbx20EH1Mut hearts and analysis of putative direct targets revealed misexpression of the retinoic acid pathway and cardiac progenitor genes. Further, we show that altered cardiac progenitor development and function contribute to the severe cardiac defects in our model. Our studies indicate that TLE-mediated repression is a primary mechanism by which Tbx20 controls gene expression.

PLIN5 interacts with FATP4 at membrane contact sites to promote lipid droplet-to-mitochondria fatty acid transport

Cells adjust their metabolism by remodeling membrane contact sites that channel metabolites to different fates. Lipid droplet (LD)-mitochondria contacts change in response to fasting, cold exposure, and exercise. However, their function and mechanism of formation have remained controversial. We focused on perilipin 5 (PLIN5), an LD protein that tethers mitochondria, to probe the function and regulation of LD-mitochondria contacts. We demonstrate that efficient LD-to-mitochondria fatty acid (FA) trafficking and ß-oxidation during starvation of myoblasts are promoted by phosphorylation of PLIN5 and require an intact PLIN5 mitochondrial tethering domain. Using human and murine cells, we further identified the acyl-CoA synthetase, FATP4 (ACSVL4), as a mitochondrial interactor of PLIN5. The C-terminal domains of PLIN5 and FATP4 constitute a minimal protein interaction capable of inducing organelle contacts. Our work suggests that starvation leads to phosphorylation of PLIN5, lipolysis, and subsequent channeling of FAs from LDs to FATP4 on mitochondria for conversion to fatty-acyl-CoAs and subsequent oxidation.

Quantitative proteomic profiling identifies global protein network dynamics in murine embryonic heart development

Defining the mechanisms that govern heart development is essential for identifying the etiology of congenital heart disease. Here, quantitative proteomics was used to measure temporal changes in the proteome at critical stages of murine embryonic heart development. Global temporal profiles of the over 7,300 proteins uncovered signature cardiac protein interaction networks that linked protein dynamics with molecular pathways. Using this integrated dataset, we identified and demonstrated a functional role for the mevalonate pathway in regulating the cell cycle of embryonic cardiomyocytes. Overall, our proteomic datasets are a resource for studying events that regulate embryonic heart development and contribute to congenital heart disease.

Breadth of SARS-CoV-2 neutralization and protection induced by a nanoparticle vaccine

Coronavirus vaccines that are highly effective against current and anticipated SARS-CoV-2 variants are needed to control COVID-19. We previously reported a receptor-binding domain (RBD)-sortase A-conjugated ferritin nanoparticle (scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected non-human primates (NHPs) from SARS-CoV-2 WA-1 infection. Here, we find the RBD-scNP induced neutralizing antibodies in NHPs against pseudoviruses of SARS-CoV and SARS-CoV-2 variants including 614G, Beta, Delta, Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5, and a designed variant with escape mutations, PMS20. Adjuvant studies demonstrate variant neutralization titers are highest with 3M-052-aqueous formulation (AF). Immunization twice with RBD-scNPs protect NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protect mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect animals from multiple different SARS-related viruses. Such a vaccine could provide broad immunity to SARS-CoV-2 variants.

Breadth of SARS-CoV-2 Neutralization and Protection Induced by a Nanoparticle Vaccine

Coronavirus vaccines that are highly effective against SARS-CoV-2 variants are needed to control the current pandemic. We previously reported a receptor-binding domain (RBD) sortase A-conjugated ferritin nanoparticle (RBD-scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected monkeys from SARS-CoV-2 WA-1 infection. Here, we demonstrate SARS-CoV-2 RBD-scNP immunization induces potent neutralizing antibodies in non-human primates (NHPs) against all eight SARS-CoV-2 variants tested including the Beta, Delta, and Omicron variants. The Omicron variant was neutralized by RBD-scNP-induced serum antibodies with a mean of 10.6-fold reduction of ID50 titers compared to SARS-CoV-2 D614G. Immunization with RBD-scNPs protected NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protected mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect NHPs and mice from multiple different SARS-related viruses. Such a vaccine could provide the needed immunity to slow the spread of and reduce disease caused by SARS-CoV-2 variants such as Delta and Omicron.

Delivering a dietetic intervention to cardiovascular patients in the Covid era

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Department of Health

Introduction

Healthy diet and body composition are core components of cardiac rehabilitation. Following the COVID outbreak in March 2020, our face-to-face cardiac rehabilitation programme (Our Hearts Our Minds) was suspended. The programme was then quickly moved to a virtual platform to continue to deliver the programme.

Purpose

Here we describe how the OHOM programme adapted our service to deliver the dietetic assessment and intervention on a virtual platform.

Methods

Pre-Covid the dietary component of OHOM consisted of a face-to-face Initial Assessment (IA) with a dietitian, group education sessions and an End of Programme assessment (EOP). Anthropometric measures and dietary habits were assessed including adherence to the Mediterranean diet via the Mediterranean Diet Score (MDS) toolkit. Using behaviour change techniques, tailored dietary advice was provided and goals agreed to educate on healthier food choices, increase adherence to Mediterranean diet and (if appropriate) promote weight loss and reduce central obesity. The assessment and intervention is now delivered virtually via telephone or video. Anthropometrics are self-reported with tape-measures supplied to assess waist circumference and advice provided on home-weighing. MDS is still assessed. The programme includes fortnightly coaching telephone consultations to review and reset goals, the option to attend a dietitian-led virtual group education session, access to a filmed educational video and submission of food diaries via the Fitbit app.

Results

From April to November 2020, 114 patients completed the virtual programme (65 telephone, 39 video). Dietetic outcomes are outlined in Table 1 with inclusion of data for a similar period one year previously (face-to-face) for comparison. Reductions in anthropometric measures and increased adherence to a cardio-protective diet were noted and the results for the two time periods are remarkably similar.

Conclusion

Delivery of a virtual dietetic component in cardiac rehabilitation is feasible, acceptable and just as effective as face-to-face based on preliminary data.

Table 1: Dietary outcomes at IA and EOP Face-to-face assessments (April - March 2019) Virtual assessments (April - November 2020) IA EOP Change IA EOP Change Mean weight (in those with BMI >25kg/m2) 86.5 85.2 -1.3 91.4 88.6 -2.8 Waist circumference (cm) 104.3 103 -1.3 107 102 -5 Mean MDS (Range 1-14) 4.4 7.5 +3.1 4.8 7.8 +3 % Consuming oily fish once per week 20 57 +37 25 68 +43 Achieving fruit and vegetable target 16 61 +45 21 57 +36

Abstract Figure. Dietitian waist circumference tutorial

Specificity and effector functions of non-neutralizing gB-specific monoclonal antibodies isolated from healthy individuals with human cytomegalovirus infection

Human cytomegalovirus (HCMV) is the most common congenital infection. A glycoprotein B (gB) subunit vaccine (gB/MF59) is the most efficacious clinically tested to date, having achieved 50% protection against primary infection of HCMV-seronegative women. We previously identified that gB/MF59 vaccination primarily elicits non-neutralizing antibody responses, with variable binding to gB genotypes, and protection associated with binding to membrane-associated gB. We hypothesized that gB-specific non-neutralizing antibody binding breadth and function are dependent on epitope and genotype specificity, and ability to interact with membrane-associated gB. We mapped twenty-four gB-specific monoclonal antibodies (mAbs) from naturally HCMV-infected individuals for gB domain specificity, genotype preference, and ability to mediate phagocytosis or NK cell activation. gB-specific mAbs were primarily specific for Domain II and demonstrated variable binding to gB genotypes. Two mAbs facilitated phagocytosis with binding specificities of Domain II and AD2. This investigation provides novel understanding on the relationship between gB domain specificity and antigenic variability on gB-specific antibody effector functions.

Human Cytomegalovirus Glycoprotein B Nucleoside-Modified mRNA Vaccine Elicits Antibody Responses with Greater Durability and Breadth than MF59-Adjuvanted gB Protein Immunization

A vaccine to prevent maternal acquisition of human cytomegalovirus (HCMV) during pregnancy is a primary strategy to reduce the incidence of congenital disease. The MF59-adjuvanted glycoprotein B (gB) protein subunit vaccine (gB/MF59) is the most efficacious vaccine tested to date for this indication. We previously identified that gB/MF59 vaccination elicited poor neutralizing antibody responses and an immunodominant response against gB antigenic domain 3 (AD-3). Thus, we sought to test novel gB vaccines to improve functional antibody responses and reduce AD-3 immunodominance. Groups of juvenile New Zealand White rabbits were administered 3 sequential doses of the full-length gB protein with an MF59-like squalene-based adjuvant, the gB ectodomain protein (lacking AD-3) with squalene adjuvant, or lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA encoding full-length gB. All vaccines were highly immunogenic with similar kinetics and comparable peak gB-binding and functional antibody responses. The AD-3-immunodominant IgG response following human gB/MF59 vaccination was closely mimicked in rabbits. Though gB ectodomain subunit vaccination eliminated targeting of epitopes in AD-3, it did not improve vaccine-elicited neutralizing or nonneutralizing antibody functions. gB nucleoside-modified mRNA-LNP-immunized rabbits exhibited an enhanced durability of vaccine-elicited antibody responses. Furthermore, the gB mRNA-LNP vaccine enhanced the breadth of IgG binding responses against discrete gB peptides. Finally, low-magnitude gB-specific T cell activity was observed in the full-length gB protein and mRNA-LNP groups, though not in ectodomain-vaccinated rabbits. Altogether, these data suggest that the use of gB nucleoside-modified mRNA-LNP vaccines is a viable strategy for improving on the partial efficacy of gB/MF59 vaccination and should be further evaluated in preclinical models.IMPORTANCE Human cytomegalovirus (HCMV) is the most common infectious cause of infant birth defects, resulting in permanent neurological disability for one newborn child every hour in the United States. After more than a half century of research and development, we remain without a clinically licensed vaccine or immunotherapeutic to reduce the burden of HCMV-associated disease. In this study, we sought to improve upon the glycoprotein B protein vaccine (gB/MF59), the most efficacious HCMV vaccine evaluated in a clinical trial, via targeted modifications to either the protein structure or vaccine formulation. Utilization of a novel vaccine platform, nucleoside-modified mRNA formulated in lipid nanoparticles, increased the durability and breadth of vaccine-elicited antibody responses. We propose that an mRNA-based gB vaccine may ultimately prove more efficacious than the gB/MF59 vaccine and should be further evaluated for its ability to elicit antiviral immune factors that can prevent HCMV-associated disease.

pH Method for Determination of Cholinesterase in Whole Blood: Collaborative Study

A collaborative study of an indirect method for determination of cholinesterase activity was conducted with cattle blood. Ten collaborators analyzed 8 samples of varying degrees of cholinesterase inhibition. The sample is diluted with a buffer, and the pH change that results from the hydrolysis of acetylcholine is monitored. Repeatability relative standard deviations (RSDr) ranged from 6.6 to 8.6%, and reproducibility relative standard deviations (RSDR) ranged from 10.7 to 17.3% for mean activities of 0.60-0.40 ΔpH/h. All samples that were completely inhibited were detected. The method was adopted first action by AOAC International for determination of cholinesterase activity in whole bovine blood.

Maternal Humoral Immune Responses Do Not Predict Postnatal HIV-1 Transmission Risk in Antiretroviral-Treated Mothers from the IMPAACT PROMISE Study

To design immune interventions that can synergize with antiretroviral therapy (ART) to reduce the rate of HIV mother-to-child transmission (MTCT), it is essential to characterize maternal immune responses in the setting of ART during pregnancy and breastfeeding and define their effect on MTCT. Prior studies reported an association between breast milk envelope (Env)-specific antibodies and antibody-dependent cell cytotoxicity (ADCC) activity with reduced postnatal transmission. In this study, we investigated whether these immune correlates were similarly associated with protection in a matched case-control study of mother-infant pairs receiving maternal ART or infant nevirapine prophylaxis during breastfeeding in the International Maternal-Pediatric-Adolescent AIDS Clinical Trials Network Promoting Maternal-Infant Survival Everywhere (PROMISE) trial, assessing postnatal transmission risk in 19 transmitting and 57 nontransmitting mothers using conditional logistic regression models adjusted for maternal plasma viral load. The odds ratios of postnatal MTCT for a 1-unit increase in an immune correlate were 3.61 (95% confidence interval [CI], 0.56, 23.14) for breast milk Env-specific secretory IgA (sIgA), 2.32 (95% CI, 0.43, 12.56) for breast milk and 2.16 (95% CI, 0.51, 9.14) for plasma Env-specific IgA, and 4.57 (95% CI, 0.68, 30.48) for breast milk and 0.96 (95% CI, 0.25, 3.67) for plasma ADCC activity, with all CIs spanning 1.0. Interestingly, although mucosal IgA responses are poor in untreated HIV-infected women, there was a strong correlation between the magnitudes of breast milk and plasma Env-specific IgA in this cohort. In this analysis of the small number of postnatal virus transmissions in the landmark PROMISE study, no single antibody response was associated with breast milk transmission risk.IMPORTANCE Each year, >150,000 infants become newly infected with HIV-1 through MTCT despite ART, with up to 42% of infections occurring during breastfeeding. Several factors contribute to continued pediatric infections, including ART nonadherence, the emergence of drug-resistant HIV strains, acute infection during breastfeeding, and poor access to ART in resource-limited areas. A better understanding of the maternal humoral immune responses that provide protection against postnatal transmission in the setting of ART is critical to guide the design of maternal vaccine strategies to further eliminate postnatal HIV transmission. In this study, we found that in women treated with antiretrovirals during pregnancy, there was a positive correlation between plasma viral load and breast milk and plasma IgA responses; however, conclusions regarding odds of MTCT risk were limited by the small sample size. These findings will inform future studies to investigate maternal immune interventions that can synergize with ART to eliminate MTCT during breastfeeding.

Complex integration of intrinsic and peripheral signaling is required for pituitary gland development

The coordination of pituitary development is complicated and requires input from multiple cellular processes. Recent research has provided insight into key molecular determinants that govern cell fate specification in the pituitary. Moreover, increasing research aimed to identify, characterize, and functionally describe the presumptive pituitary stem cell population has allowed for a better understanding of the processes that govern endocrine cell differentiation in the developing pituitary. The culmination of this research has led to the ability of investigators to recapitulate some of embryonic pituitary development in vitro, the first steps to developing novel regenerative therapies for pituitary diseases. In this current review, we cover the major players in pituitary stem/progenitor cell function and maintenance, and the key molecular determinants of endocrine cell specification. In addition, we discuss the contribution of peripheral hormonal regulation of pituitary gland development, an understudied area of research.

Effects of Exposure to the Endocrine-Disrupting Chemical Bisphenol A During Critical Windows of Murine Pituitary Development

Critical windows of development are often more sensitive to endocrine disruption. The murine pituitary gland has two critical windows of development: embryonic gland establishment and neonatal hormone cell expansion. During embryonic development, one environmentally ubiquitous endocrine-disrupting chemical, bisphenol A (BPA), has been shown to alter pituitary development by increasing proliferation and gonadotrope number in females but not males. However, the effects of exposure during the neonatal period have not been examined. Therefore, we dosed pups from postnatal day (PND)0 to PND7 with 0.05, 0.5, and 50 μg/kg/d BPA, environmentally relevant doses, or 50 μg/kg/d estradiol (E2). Mice were collected after dosing at PND7 and at 5 weeks. Dosing mice neonatally with BPA caused sex-specific gene expression changes distinct from those observed with embryonic exposure. At PND7, pituitary Pit1 messenger RNA (mRNA) expression was decreased with BPA 0.05 and 0.5 μg/kg/d in males only. Expression of Pomc mRNA was decreased at 0.5 μg/kg/d BPA in males and at 0.5 and 50 μg/kg/d BPA in females. Similarly, E2 decreased Pomc mRNA in both males and females. However, no noticeable corresponding changes were found in protein expression. Both E2 and BPA suppressed Pomc mRNA in pituitary organ cultures; this repression appeared to be mediated by estrogen receptor-α and estrogen receptor-β in females and G protein-coupled estrogen receptor in males, as determined by estrogen receptor subtype-selective agonists. These data demonstrated that BPA exposure during neonatal pituitary development has unique sex-specific effects on gene expression and that Pomc repression in males and females can occur through different mechanisms.

Incomplete offspring sex bias in Australian populations of the butterfly Eurema hecabe

Theory predicts unified sex ratios for most organisms, yet biases may be engendered by selfish genetic elements such as endosymbionts that kill or feminize individuals with male genotypes. Although rare, feminization is established for Wolbachia-infected Eurema butterflies. This paradigm is presently confined to islands in the southern Japanese archipelago, where feminized phenotypes produce viable all-daughter broods. Here, we characterize sex bias for E. hecabe in continental Australia. Starting with 186 wild-caught females, we reared >6000 F1-F3 progeny in pedigree designs that incorporated selective antibiotic treatments. F1 generations expressed a consistent bias across 2 years and populations that was driven by an ~5% incidence of broods comprising ⩾80% daughters. Females from biased lineages continued to overproduce daughters over two generations of outcrossing to wild males. Treatment with antibiotics of differential strength influenced sex ratio only in biased lineages by inducing an equivalent incomplete degree of son overproduction. Brood sex ratios were nevertheless highly variable within lineages and across generations. Intriguingly, the cytogenetic signature of female karyotype was uniformly absent, even among phenotypic females in unbiased lineages. Molecular evidence supported the existence of a single Wolbachia strain at high prevalence, yet this was not clearly linked to brood sex bias. In sum, we establish an inherited, experimentally reversible tendency for incomplete offspring bias. Key features of our findings clearly depart from the Japanese feminization paradigm and highlight the potential for more subtle degrees of sex distortion in arthropods.

Identification of a novel progenitor cell marker, grainyhead-like 2 in the developing pituitary

BACKGROUND

Pituitary stem/progenitor cells give rise to all of the endocrine cell types within the pituitary gland and are necessary for both development and gland homeostasis. Recent studies have identified several key factors that characterize the progenitor cell population. However, little is known about the factors that regulate progenitor cell differentiation and maintenance. Therefore, it is crucial to identify novel factors that help elucidate mechanisms of progenitor cell function in the developing pituitary. Our studies are the first to characterize the expression of Grainyhead-like 2 (GRHL2), a transcription factor known to regulate progenitor cell plasticity, in the developing pituitary.

RESULTS

Our studies show GRHL2 expression is highest in the embryonic and early postnatal pituitary and is localized in pituitary progenitor cells. We demonstrate GRHL2 expression is changed in Notch2 cKO and Prop1^df/df mice, mouse models that display progenitor cell number defects. In addition, our studies indicate a potential relationship between Notch signaling and GRHL2 expression in the developing pituitary.

CONCLUSIONS

Taken together, our results indicate GRHL2 as a novel progenitor cell maker in the developing pituitary that may contribute to progenitor cell function and maintenance. Developmental Dynamics 245:1097-1106, 2016. © 2016 Wiley Periodicals, Inc.

Defining the mechanisms and cues that influence cytotoxic T cell homeostasis during malnourishment (LYM2P.727)

T cell homeostasis is clearly disrupted by malnutrition, but the precise cues and mechanisms through which it occurs are unknown. Short-term malnutrition reduces the size of the peripheral CD8+ T population in mice. Perhaps paradoxically, malnourished CD8+ T cells are less sensitive to death-by-neglect and express higher levels of CD127, a component of the IL-7 receptor. We aimed to identify whether vitamin and mineral deficiency or reduced caloric intake triggers these changes and to better understand the molecular mechanisms through which such changes occur. While vitamin and mineral deficiency is not sufficient to reduce total CD8+ T cell numbers or trigger CD127 up-regulation, it is sufficient to reduce CD8+ T cell sensitivity to death-by-neglect. Mechanistically, we have determined that the reduced sensitivity to death-by-neglect observed in malnourished CD8+ T cells is Foxo1-dependent. Given that CD127 is a transcriptional target of Foxo1, additional studies were conducted to determine if CD127 is up-regulated or if CD127low CD8+ T cells are simply out-competed in a malnourished environment. Our results suggest that during malnourishment, Foxo1 induces the up-regulation of CD127 on CD8+ T cells, which may relate to the cells’ reduced sensitivity to growth factor withdrawal. While different mechanisms may be triggered by calorie versus vitamin and mineral deficiency, both deficiencies reduce CD8+ T cell sensitivity to death-by-neglect.

Strategies to prevent and reduce diabetes and obesity in Sacramento, California: the African American Leadership Coalition and University of California, Davis

BACKGROUND

Diabetes is one of the leading causes of illness and death for African Americans and people of African descent throughout the United States and in the city and county of Sacramento, California. The involvement of families and communities in developing prevention strategies can increase the likelihood that behavioral changes will be sustained.

CONTEXT

Three member organizations of the African American Leadership Coalition (AALC) entered into a partnership with the University of California, Davis (UC Davis) to engage families in developing a process to identify barriers to diabetes and obesity prevention and reduction, exchange strategies, and create action plans for prevention.

METHODS

The intervention comprised 3 phases: 1) coalition formation and training; 2) data collection, analysis, and dissemination of results; and 3) development of family and community action plans. Academic and community partners planned and implemented all project phases together.

OUTCOMES

Sources of information about diabetes and obesity were primarily doctors and the Internet; barriers were related to lack of time needed to prepare healthy meals, high food costs, transportation to fresh markets, motivation around healthy habits, and unsafe environments. Action plans addressed behavioral change and family cohesion. The group discussion format encouraged mutual support and suggestions for better eating and physical exercise habits.

INTERPRETATION

This collaborative partnership model can strengthen existing group relationships or promote new affiliations that form the basis for future action coalitions. Participants worked both within and across groups to exchange information, stories of success and challenges, and specific health improvement strategies.

Membrane bioreactor application within the treatment of high-strength textile effluent

A pilot-scale dual-stage membrane bioreactor (dsMBR) incorporating two ultra-filtration (UF) side-stream membrane modules was designed, constructed, operated and evaluated on-site for treating high-strength textile effluent. The effluent stream was characterised by a COD range of between 45 to 2,820 mg/L and an average BOD of 192.5 mg/L. The dsMBR achieved an average COD reduction of 75% with a maximum of 97% over the 9 month test period. The COD concentration obtained after dsMBR treatment averaged at 190 mg/L, which was well within the discharge standard. The average reduction in turbidity and TSS were 94% and 19.6%, respectively, during the UF-MBR stage of the system. Subsequent treatment of the UF-permeate with nanofiltration (NF) and reverse osmosis (RO) removed both the residual colour and remaining salt. A consistent reduction in the color of the incoming effluent was evident. The ADMI was reduced from an average of 659 to ∼20, a lower ADMI and colour compared to the potable water. An average conductivity rejection of 91% was achieved with conductivity being reduced from an average of 7,700 to 693 μS/cm and the TDS reduced from an average of 5,700 to 473 mg/L, which facilitated an average TDS rejection of 92%.

Treatment of paper mill effluent using an anaerobic/aerobic hybrid side-stream membrane bioreactor

This paper presents the design and operational performance data of an anaerobic/aerobic hybrid side-stream Membrane Bioreactor (MBR) process for treating paper mill effluent operated over a 6 month period. The paper mill effluent stream was characterized by a chemical oxygen demand (COD) range of between 1,600 and 4,400 mg/L and an average BOD of 2,400 mg/L. Despite large fluctuations in COD feed concentration, stable process performance was achieved. The anaerobic Expanded Granular Sludge Bed (EGSB) pre-treatment step effectively lowered the organic loading by 65 to 85%, thus lowering the MBR COD feed concentration to consistently below 750 mg/L. The overall MBR COD removal was consistent at an average of 96%, regardless of the effluent COD or changes in the hydraulic retention time (HRT) and organic loading rate (OLR). Combining a high-rate anaerobic pre-treatment EGSB with a Modified Ludzack-Ettinger (MLE) MBR process configuration produced a high quality permeate. Preliminary NF and RO results indicated an overall COD removal of around 97 and 98%, respectively.

Can Cycling Performance in an Early Morning, Laboratory-Based Cycle Time-Trial be Improved by Morning Exercise the Day Before?

The normal circadian rhythm in exercise performance may be altered by the habitual timing of training. We have investigated if morning time trial performance is affected by the time at which moderate exercise is performed on the previous day. Eight male cyclists undertook two separate exercise sessions of sub-maximal cycle ergometry (60% V.O2peak for 30 min) at 07:00 h and 12:00 h the day before a 16.1-km time trial at 07:00 h. Heart rate, power output, ratings of perceived exertion, and rectal temperature were measured at rest and every 5 min in the pre-time trial exercises, and every 1.61 km during the time trial. Blood samples were taken at rest and immediately after the time trial for the measurement of lactate concentration. The time trial performed the day after the 07:00 h sub-maximal exercise was completed in 1672+/-135 s, compared to 1706+/-159 s for the time trial performed the day after the noon pre-time trial exercise (p=0.027). The time trial after exercise the previous morning was associated with higher work-rates (p=0.031), a higher net lactate accumulation after the time trial (p=0.018), and a trend for higher heart rates (p=0.093) compared to the time trial after exercise the previous noon. These findings suggest that cycling performance in an early morning time trial is improved if an athlete participates in early-morning rather than noontime moderate exercise the day before. This finding cannot be attributed to the physiological responses to the exercise on the pre-time trial day or to environmental factors. It is suggested that it might partly reflect an advantage gained by performing exercise in the day(s) immediately beforehand at the same time as the competition.

Sciatic nerve blockade improves early postoperative analgesia after open repair of calcaneus fractures

OBJECTIVE

To determine the effectiveness of analgesia, with or without sciatic nerve blockade, after open repair of calcaneus fracture.

DESIGN

Randomized, prospective trial involving 30 patients divided into 3 groups of 10, all having open repair of calcaneus fractures. Group 1 used morphine patient-controlled analgesia alone. Groups 2 and 3 had morphine patient-controlled analgesia and a "one-shot" bupivacaine sciatic nerve blockade, either presurgically (group 2) or postsurgically (group 3).

SETTING

Harborview Medical Center operating rooms and orthopedic floors.

OUTCOME MEASURES

Morphine use over 24 hours, visual analogue scale pain scores, and sciatic nerve blockade duration.

RESULTS

In the absence of sciatic nerve blockade, initial postoperative pain was marked, even with a mean recovery room dose of intravenous morphine more than 30 mg. Sciatic nerve blockade with bupivacaine had a mean duration of 14 hours and substantially reduced pain for the first 24 postoperative hours. Presurgical blockade confers no advantage over postsurgical blockade.

CONCLUSION

Sciatic nerve blockade confers significant benefit over morphine alone for analgesia after open repair of calcaneus fractures. Postsurgical sciatic nerve blockade provides the longest possible postoperative block duration.

Decision technology

This review is about decision technology-the rules and tools that help us make wiser decisions. First, we review the three rules that are at the heart of most traditional decision technology-multi-attribute utility, Bayes' theorem, and subjective expected utility maximization. Since the inception of decision research, these rules have prescribed how we should infer values and probabilities and how we should combine them to make better decisions. We suggest how to make best use of all three rules in a comprehensive 19-step model. The remainder of the review explores recently developed tools of decision technology. It examines the characteristics and problems of decision-facilitating sites on the World Wide Web. Such sites now provide anyone who can use a personal computer with access to very sophisticated decision-aiding tools structured mainly to facilitate consumer decision making. It seems likely that the Web will be the mode by means of which decision tools will be distributed to lay users. But methods for doing such apparently simple things as winnowing 3000 options down to a more reasonable number, like 10, contain traps for unwary decision technologists. The review briefly examines Bayes nets and influence diagrams-judgment and decision-making tools that are available as computer programs. It very briefly summarizes the state of the art of eliciting probabilities from experts. It concludes that decision tools will be as important in the 21st century as spreadsheets were in the 20th.

Factors affecting long-term expression of a secreted transgene product after intravenous administration of a retroviral vector

We have studied parameters affecting in vivo expression of human growth hormone (hGH) in mice after intravenous administration of a retroviral vector encoding the protein as a model system for clotting factor VIII gene therapy. Such treatment results in a brief burst of high-level expression followed by lower level sustained expression of the hGH in the circulation. The major targets for transduction in the mouse are liver and spleen. Such direct transduction (i.e., without surgical or chemical induction of cell division) requires vector at high titer (>/=10(8) cfu/ml) and is dose dependent. Transduction efficiency decreases with increasing age of the recipient. Nevertheless, long-term expression in adults is observed after administration of vector as a split dose on 2 consecutive days. We also show that anti-vector immune responses may enhance long-term expression and that both anti-vector and anti-transgene immunity can be modulated. This work provides a framework for the rational development of means to enhance the efficiency of retroviral vectors for use in clinical gene replacement therapy.

Transport of proteins into and across the thylakoid membrane

The biogenesis of thylakoid proteins is a complex issue that requires the operation of at least four pathways within the chloroplast. Two of the pathways are used for soluble lumenal proteins, where the proteins bear cleavable targeting signals that are recognized by one of two distinct translocases. These pathways differ in fundamental respects. A subset of lumenal proteins are transported in an unfolded state by a typical Sec system, whereas others are transported by a novel class of translocase that appears to function primarily in the transport of fully-folded proteins. Related protein translocases have now been shown to operate in a wide variety of bacterial species, suggesting a widespread requirement for the translocation of folded proteins across biological membranes. Numerous integral membrane proteins are also targeted into the thylakoid membrane, and these too follow at least two distinct routes. Some proteins use a signal recognition particle-dependent pathway that requires GTP and unidentified apparatus in the thylakoid membrane. Others, however, require none of the known targeting factors and may insert spontaneously into the membrane. In this article, the rationale behind this pathway complexity is discussed in relation to the properties of the substrate proteins and the evolutionary origins of the chloroplast.

Phase I trial of interferon-gamma (IFN-gamma) retroviral vector administered intratumorally to patients with metastatic melanoma

BACKGROUND

Interferon-gamma (IFN-gamma) gene/retroviral vector cell vaccinations have generated protective responses from unmodified tumor cell challenges as well as a regression of established tumors in animal models. The purpose of this trial was to determine the feasibility and safety of a direct intratumoral injection of IFN-gamma retroviral vector in advanced melanoma patients.

METHODS

This was a phase I study, in which 13 patients received a single daily injection of a retroviral vector with the IFN-gamma gene for 5 consecutive days (1.5 x 10(8) colony-forming units total dose); patients subsequently underwent resection of the injected lesion to confirm DNA transduction in situ.

RESULTS

No toxicity related to the injected vector was observed. Replication competent retrovirus was not observed in any prepared samples (n = 65). IFN-gamma expression was confirmed in 3 of 10 harvested tumor samples; one was equivocal, and DNA transduction was unable to be confirmed by enzyme-linked immunospot assay in six samples.

CONCLUSIONS

An injection of IFN-gamma gene/retroviral vector is well tolerated. DNA transduction was demonstrated in human subjects, confirming the feasibility of the direct injection approach for the gene therapy of solid tumors. Further trials to determine optimal schedule and potential efficacy are indicated.

Fatal pancarditis associated with human granulocytic Ehrlichiosis in a 44-year-old man

Human cases of infection with a granulocytotropic Ehrlichia species closely related to Ehrlichia equi are now being described with increasing frequency in the United States, especially in areas where Lyme disease is already endemic. We describe a case of fatal pancarditis during the course of human granulocytic ehrlichiosis (HGE) in a 44-year-old outdoor worker who was previously treated for presumptive Lyme disease. Serological and molecular diagnostic tests for Borrelia burgdorferi and Babesia microti infections were negative. Postmortem serum specimens were seroreactive for HGE, and molecular evidence of infection with the HGE agent was obtained. These findings suggest that carditis may be a manifestation of HGE, further complicating the differential diagnosis of tick-borne illness.

Incidence, presenting features, risk factors and significance of late onset septicemia in very low birth weight infants. The National Institute of Child Health and Human Development Neonatal Research Network

BACKGROUND

Septicemia is a major antecedent of morbidity and mortality in very low birth weight (501- to 1500-g) infants. Our purpose was to determine prospectively the incidence, clinical presentation, laboratory features, risk factors, morbidity and mortality associated with late onset septicemia in infants 501 to 1500 g.

METHODS

Clinical data were prospectively collected for 2416 infants enrolled in a multicenter trial to determine the efficacy of intravenous immunoglobulin in preventing nosocomial infections. Septicemia was confirmed by positive blood culture in 395 symptomatic infants. Multivariate analyses of factors associated with septicemia were performed.

RESULTS

Sixteen percent of VLBW infants developed septicemia at a median age of 17 days. Factors associated with septicemia by logistic regression included male gender, lower gestational age and birth weight and decreased baseline serum IgG concentrations. Increasing apnea (55%), feeding intolerance, abdominal distension or guaiac-positive stools (43%), increased respiratory support (29%), lethargy and hypotonia (23%) were the dominant presenting features of septicemia. An abnormal white blood cell count (46%), unexplained metabolic acidosis (11%) and hyperglycemia (10%) were the most common laboratory indicators. Septicemic infants, compared with nonsepticemic infants, had significantly increased mortality (21% vs. 9%), longer hospital stay (98 vs. 58 days) and more serious morbidity, including severe intraventricular hemorrhage, bronchopulmonary dysplasia and increased ventilator days (P < 0.001).

CONCLUSIONS

Late onset septicemia is common in very low birth weight infants, and the rate is inversely proportional to gestational age and birth weight. Septicemia is more common in males and those with low initial serum IgG values. A set of clinical signs (apnea, bradycardia, etc.) and laboratory values (leukocytosis, immature white blood cells and neutropenia) increase the probability of late onset sepsis, but they have poor positive predictive value.

Hailfinder. Tools for and experiences with Bayesian normative modeling

Bayes Nets (BNs) and Influence Diagrams (IDs), new tools that use graphic user interfaces to facilitate representation of complex inference and decision structures, will be the core elements of new computer technologies that will make the 21st century the Century of Bayes. BNs are a way of representing a set of related uncertainties. They facilitate Bayesian inference by separating structural information from parameters. Hailfinder is a BN that predicts severe summer weather in Eastern Colorado. Its design led to a number of novel ideas about how to build such BNs. Issues addressed included representation of spatial location, categorization of days, system boundaries, pruning, and methods for eliciting and checking on the appropriateness of conditional probabilities. The technology of BNs is improving rapidly. Especially important is the emergence of ways of reusing fragments of BNs. BNs and IDs are not just important design tools; they also represent a major enhancement of the understanding about how important intellectual tasks typically performed by people should and can be performed.

Hailfinder. Tools for and experiences with Bayesian normative modeling

Bayes Nets (BNs) and Influence Diagrams (IDs), new tools that use graphic user interfaces to facilitate representation of complex inference and decision structures, will be the core elements of new computer technologies that will make the 21st century the Century of Bayes. BNs are a way of representing a set of related uncertainties. They facilitate Bayesian inference by separating structural information from parameters. Hailfinder is a BN that predicts severe summer weather in Eastern Colorado. Its design led to a number of novel ideas about how to build such BNs. Issues addressed included representation of spatial location, categorization of days, system boundaries, pruning, and methods for eliciting and checking on the appropriateness of conditional probabilities. The technology of BNs is improving rapidly. Especially important is the emergence of ways of reusing fragments of BNs. BNs and IDs are not just important design tools; they also represent a major enhancement of the understanding about how important intellectual tasks typically performed by people should and can be performed.

An epidemic of Malassezia pachydermatis in an intensive care nursery associated with colonization of health care workers' pet dogs

BACKGROUND

Malassezia species are lipophilic yeasts that are emerging as nosocomial pathogens, particularly in low-birth-weight neonates who receive lipid emulsions. When a cluster of patients with Malassezia pachydermatis infection was identified in an intensive care nursery, we initiated an investigation.

METHODS

A case patient was defined as any infant in the intensive care nursery who had a positive culture for M. pachydermatis between October 17, 1993, and January 18, 1995. We conducted a cohort study to identify risk factors for colonization and infection with M. pachydermatis. We collected cultures from the infants and the health care workers and from the health care workers' pets, since this organism has been associated with otitis externa in dogs.

RESULTS

Fifteen infants met the case definition: eight with bloodstream infections, two with urinary tract infections, one with meningitis, and four with asymptomatic colonization. The case patients were significantly more likely than the other infants to weigh 1300 g or less (15 of 65 vs. 0 of 419, P<0.001). In a multivariate analysis of infants weighing 1300 g or less, the independent risk factors for colonization or infection with M. pachydermatis were a greater severity of concomitant illness (odds ratio, 19.7; P=0.001), arterial catheterization for nine or more days (odds ratio, 29.5; P=0.027), and exposure to Nurse A (odds ratio, 74.7; P=0.004). In a point-prevalence survey, 9 additional infants, 1 health care worker, and 12 of the health care workers' pet dogs had positive cultures for M. pachydermatis. The isolates from all 15 case patients, the 9 additional colonized infants, 1 health care worker, and 3 of the 12 dogs had identical patterns of restriction-fragment-length polymorphisms.

CONCLUSIONS

In this outbreak, it is likely that M. pachydermatis was introduced into the intensive care nursery on health care workers' hands after being colonized from pet dogs at home. The organism persisted in the nursery through patient-to-patient transmission.

Evidence for localization of biologically active recombinant retroviral vector to lymph nodes in mice injected intramuscularly

We have developed a novel gene transfer drug, HIV-IT(V), for the treatment of HIV infection in humans. HIV-IT(V) is a retroviral vector encoding the HIV-1 IIIB env and rev genes and a neomycin resistance marker gene (neor). We have recently reported that HIV-IT(V) administered intramuscularly to male mice localizes primarily to the site of injection. In this study, we have investigated more extensively the localization and biological activity of HIV-IT(V) administered intramuscularly to female mice. Consistent with our previous findings, retroviral DNA was detected by PCR at the site of injection. Retroviral DNA was also detected in proximal lymph nodes, a tissue not examined previously. Potential for drainage of vector particles to regional lymph nodes was indicated by experiments showing that intramuscular injection of fluorescein-labeled latex beads concentrated in the regional lymph nodes in mice. The localization of retroviral DNA to the injection site and regional lymph nodes may play a role in the induction of the HIV-specific CTL responses detected in splenocyte populations isolated from mice 21 days after injection with HIV-IT(V).

Recombinant retroviral vector delivered intramuscularly localizes to the site of injection in mice

A murine retroviral vector encoding the human immunodeficiency virus type 1 (HIV-1) env and rev genes can be used to induce cytotoxic T lymphocyte responses. Immune responses can be induced by an ex vivo treatment, in which autologous cells are transduced in vitro and re-introduced to the donor, or by direct administration of retroviral vector via intramuscular injection. In this study we have used polymerase chain reaction (PCR) analysis to examine the distribution of recombinant murine retrovirus directly administered to mice. Mice were injected intramuscularly with HIV-IT(V), an amphotropic murine leukemia virus (MLV)-based retroviral vector carrying the HIV-1 env/rev genes and a neomycin resistance marker gene. Detection of the HIV-1 env gene in DNA isolated from injection sites demonstrated in vivo transduction. No evidence of transduction was observed in the testes, spleen, kidney, or thymus. Retroviral DNA was detected in the liver of one animal in the study. These data suggest that retroviral vector administered intramuscularly to mice localizes primarily to the site of injection and that measurable transduction in the testes does not occur.

A controlled trial of intravenous immune globulin to reduce nosocomial infections in very-low-birth-weight infants. National Institute of Child Health and Human Development Neonatal Research Network

BACKGROUND

Nosocomial infections are a major cause of morbidity and mortality in premature infants. As a rule, their low serum gamma globulin levels at birth subsequently decline to hypogammaglobulinemic values; hence, prophylactic administration of intravenous immune globulin may reduce the rate of hospital-acquired infections.

METHODS

In this prospective, multicenter, two-phase controlled trial, 2416 infants were stratified according to birth weight (501 to 1000 g and 1001 to 1500 g) and randomly assigned to an intravenous immune globulin group (n = 1204) or a control group (n = 1212). Control infants were given placebo infusions during phase 1 of the study (n = 623) but were not given any infusions during phase 2 (n = 589). Infants weighing 501 to 1000 g at birth were given 900 mg of immune globulin per kilogram of body weight, and infants weighing 1001 to 1500 g at birth were given a dose of 700 mg per kilogram. The immune globulin infusions were repeated every 14 days until the infants weighed 1800 g, were transferred to another center, died, or were sent home from the hospital.

RESULTS

Nosocomial infections of the blood, meninges, or urinary tract occurred in 439 of the 2416 infants (18.2 percent): 208 (17.3 percent) in the immune globulin group and 231 (19.1 percent) in the control group (relative risk, 0.91; 95 percent confidence interval, 0.77 to 1.08). Septicemia occurred in 15.5 percent of the immune globulin recipients and 17.2 percent of the controls. During phase 1 the rate of nosocomial infections was 13.4 percent in the immune globulin group and 17.8 percent in the control group; the respective rates during phase 2 were 21.0 percent and 20.4 percent. The predominant organisms included gram-positive cocci (53.0 percent), gram-negative bacilli (22.4 percent), and candida species (16.0 percent). Adverse reactions were rarely observed during the infusions. Immune globulin therapy had no effect on respiratory distress syndrome, bronchopulmonary dysplasia, intracranial hemorrhage, the duration of hospitalization, or mortality. The incidence of necrotizing enterocolitis was 12.0 percent in the immune globulin group and 9.5 percent in the control group.

CONCLUSIONS

Prophylactic use of intravenous immune globulin failed to reduce the incidence of hospital-acquired infections in very-low-birth-weight infants.

High intensity training-induced changes in skeletal muscle antioxidant enzyme activity

These experiments tested the hypothesis that high intensity (interval) training is superior to moderate intensity (continuous) exercise training in the upregulation of antioxidant enzyme activity in skeletal muscle. To test this postulate, we examined changes in oxidative and antioxidant enzyme activities in rat skeletal muscle following 12 wk of either interval (6 x approximately 5-min intervals at approximately 80-95% VO2max) or continuous (45 min at approximately 70% VO2max) exercise training. Both continuous and interval training resulted in significantly elevated (P < 0.05) succinate dehydrogenase (SDH) and 3-hydroxyacyl-CoA-dehydrogenase (HADH) activities in the gastrocnemius (G) and soleus (S) muscles compared with controls. SDH and HADH activities in the G and S muscles did not differ between the two exercise groups. Glutathione peroxidase (GPX) activity exceeded controls (P < 0.05) in only the interval trained S muscle. Soleus superoxide dismutase (SOD) activity was higher (P < 0.05) in both exercise groups compared with controls. No differences in SOD activity existed between interval and continuous trained animals. We conclude that when matched for oxygen cost, interval and continuous exercise training result in similar increases in SOD activity. However, high intensity interval exercise is superior to moderate intensity continuous exercise in the promotion of GPX activity in the S.

Development of Anaplasma marginale in salivary glands of male Dermacentor andersoni

Development of the rickettsia, Anaplasma marginale, in salivary glands of male Dermacentor andersoni exposed as nymphs or adult ticks, was studied indirectly by inoculation of susceptible calves with homogenates and directly by examination, using light microscopy and a DNA probe; some unfed ticks were incubated before tissues were collected. Salivary gland homogenates made from ticks in every treatment group caused anaplasmosis when injected into susceptible calves; prepatent periods decreased as the time that ticks had fed increased. Colonies of A marginale were seen only in salivary glands of ticks exposed as adults and not in those exposed as nymphs; the percentage of salivary gland acini infected in these ticks increased linearly with feeding time. However, the probe detected A marginale DNA in salivary glands of ticks from both groups; the amount of DNA detected increased as feeding time was extended. The amount of A marginale DNA appeared to remain constant in gut tissues, but to increase in salivary glands. Salivary glands of adult-infected male ticks that were incubated, but did not feed a second time, became infected with A marginale, and the pattern of infection of acini varied with incubation temperature. Development of A marginale in salivary glands appears to be coordinated with the tick feeding cycle; highest infection rate was observed in ticks exposed as adults.

Endurance training-induced increases in expiratory muscle oxidative capacity

Recent evidence demonstrates that endurance exercise training improves the oxidative capacity of the major mammalian inspiratory muscle (e.g., costal diaphragm). In contrast, no data exist concerning the effects of exercise training on abdominal expiratory muscles. We tested the hypothesis that 12 wk of endurance exercise training would significantly increase the activity of selected beta oxidation and Krebs cycle enzymes of abdominal expiratory muscles of the rat. To test this hypothesis two groups of female Sprague-Dawley rats were studied: group 1, continuous exercise training (n = 13); and group 2, sedentary control (n = 6). Exercise trained animals ran 5 d.wk-1 on a motorized treadmill for 45 min.d-1 at approximately 75-80% VO2max. When compared with controls, exercise training resulted in elevated (P less than 0.05) activities of 3-hydroxy-acyl-Co-A dehydrogenase (HADH) and citrate synthase (CS) in two abdominal expiratory muscles (rectus abdominus and external obliques). In contrast, training did not alter (P greater than 0.05) CS or HADH activity in the internal obliques/transversus abdominus muscles. In general, the training-induced increases in expiratory muscles CS activity were relatively small (approximately 10-13%) when compared with the training-induced increase in CS activity in the plantaris muscle (approximately 44%). These data demonstrate that continuous exercise training results in small but statistically significant improvements in the oxidative and beta oxidation capacities of expiratory muscles.

Development of Anaplasma marginale in male Dermacentor andersoni transferred from parasitemic to susceptible cattle

The development and transmission of Anaplasma marginale was studied in Dermacentor andersoni males. Laboratory-reared male D andersoni were allowed to feed for 7 days on a calf with ascending A marginale parasitemia. The ticks were then held in a humidity chamber for 7 days before being placed on 2 susceptible calves. Anaplasmosis developed in the calves after incubation periods of 24 and 26 days. Gut and salivary glands were collected from ticks on each day of the 23-day experiment and examined with light and electron microscopy. Colonies of A marginale were first observed in midgut epithelial cells on the sixth day of feeding on infected calves, with the highest density of colonies found in gut cells while ticks were between feeding periods. The first colonies contained 1 large dense organism that subsequently gave rise to many reticulated organisms. Initially, these smaller organisms were electron-lucent and then became electron-dense. On the fifth day after ticks were transferred to susceptible calves for feeding, A marginale colonies were found in muscle cells on the hemocoel side of the gut basement membrane. A final site for development of A marginale was the salivary glands. Colonies were first seen in acinar cells on the first day that ticks fed on susceptible calves, with the highest percentage of infected host cells observed on days 7 to 9 of that feeding. Organisms within these colonies were initially electron-lucent, but became electron-dense.

Detection of colonies of Anaplasma marginale in salivary glands of three Dermacentor spp infected as nymphs or adults

Salivary glands from males of 3 Dermacentor species (D andersoni, D variabilis and D occidentalis) that were infected with either the Virginia or Idaho isolate of Anaplasma marginale as nymphs or adults were examined for colonies of A marginale by use of light and electron microscopy. Prior to dissection of salivary glands, exposed ticks were held at 25 C for 15 to 18 days, followed by a 3-day incubation at 37 C. Ticks of 2 species transmitted A marginale to calves; the third tick species was confirmed infected by demonstration of typical colonies in tick gut cells, but transmission was not attempted; Colonies of A marginale were seen with light microscopy in salivary glands of all 3 species of ticks; they were located in acinar cells that contained simple granules. Colonies varied morphologically from small, compact ones to larger structures that contained distinct organisms and often were adjacent to the host cell nucleus. Electron microscopy confirmed that the colonies were rickettsial organisms. Morphologic features of A marginale varied and included reticulated forms, forms with electron-dense centers, and small particles; these various forms were similar to those described previously in midgut epithelial cells of ticks. We believe that the organism seen within tick salivary glands may replicate in the glands before its transmission to the vertebrate host.

Chronic hypoxia alters structure and transmitter dynamics in dog pulmonary artery

Confinement of dogs to 10% oxygen for 14 days caused erythropoiesis and pulmonary hypertension. Histological sections of the lung tissue showed thickening of the smooth muscle component of muscular arteries and arterioles. Segments of pulmonary artery from dogs exposed to hypoxia were superfused under continuation of hypoxic conditions or after return to oxygenated conditions. Parallel segments of pulmonary artery from normal dogs were also studied. Norepinephrine stores were labeled with [3H]norepinephrine and measurements were made of [3H]norepinephrine and its radiolabeled metabolites (separated by column chromatography) in superfusates using liquid scintillation spectrometry. Chronic hypoxia (1) reduced neuronal uptake of NE from synaptic clefts, (2) reduced the content of DOPEG in superfusate from tissues studied during continuation of hypoxic conditions and in tissues studied after return to oxygenated conditions, (3) increased extraneuronal uptake of NE and (4) increased overflow of NE from synaptic clefts. In similar segments of pulmonary artery removed from the same lung, endogenous free and conjugated norepinephrine and dopamine were measured in pulmonary artery by liquid chromatography with electrochemical detection. The tissue content of free norepinephrine after stimulation was reduced, which was compatible with the reduction in neuronal uptake. Conjugated norepinephrine was a minor metabolite and was increased modestly compared to concentrations reported previously in pulmonary artery from normal dogs.

Variability in 28-day outcomes for very low birth weight infants: an analysis of 11 neonatal intensive care units

A retrospective study of all infants weighing 701 to 1,500 g born at 11 neonatal intensive care centers during 1983 and 1984 was performed to determine whether two specific 28-day outcomes, survival and survival without the need for supplemental oxygen, varied among the centers. Survival without the need for supplemental oxygen was chosen as a reflection of infants surviving without chronic lung disease. There were 1,776 live-born infants delivered during the 2-year study period. Of these infants, 85% (1,512) survived 28 days, a range of 80% to 92% at the individual centers. A total of 60% (1,056) of the infants were alive without supplemental oxygen on day 28, a range of 51% to 70% at the individual centers. Multivariate analysis demonstrated that both survival on day 28 (chi 2 = 23.9, P less than .01) and survival without supplemental oxygen on day 28 (chi 2 = 44.2, P less than .0001) varied significantly among centers after the effects of birth weight, gender, and race were taken into account. Female gender, nonwhite race, and increased birth weight were factors associated with improved rates of survival and survival without supplemental oxygen. The magnitude of outcome variation among centers was estimated by using the logistic regression models to predict what the outcomes would be if each center were to treat a standardized population consisting of all 1,776 study infants.(ABSTRACT TRUNCATED AT 250 WORDS)