Prevalence and duration of SARS-CoV-2 fecal shedding in breastfeeding dyads following maternal COVID-19 diagnosis

Background

There is a paucity of data on the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in feces of lactating women with coronavirus disease 2019 (COVID-19) and their breastfed infants as well as associations between fecal shedding and symptomatology.

Objective

We examined whether and to what extent SARS-CoV-2 is detectable in the feces of lactating women and their breastfed infants following maternal COVID-19 diagnosis.

Methods

This was a longitudinal study carried out from April 2020 to December 2021 involving 57 breastfeeding maternal-infant dyads: 33 dyads were enrolled within 7 d of maternal COVID-19 diagnosis, and 24 healthy dyads served as controls. Maternal/infant fecal samples were collected by participants, and surveys were administered via telephone over an 8-wk period. Feces were analyzed for SARS-CoV-2 RNA.

Results

Signs/symptoms related to ears, eyes, nose, and throat (EENT); general fatigue/malaise; and cardiopulmonary signs/symptoms were commonly reported among mothers with COVID-19. In infants of mothers with COVID-19, EENT, immunologic, and cardiopulmonary signs/symptoms were most common, but prevalence did not differ from that of infants of control mothers. SARS-CoV-2 RNA was detected in feces of 7 (25%) women with COVID-19 and 10 (30%) of their infants. Duration of fecal shedding ranged from 1-4 wk for both mothers and infants. SARS-CoV-2 RNA was sparsely detected in feces of healthy dyads, with only one mother's and two infants' fecal samples testing positive. There was no relationship between frequencies of maternal and infant SARS-CoV-2 fecal shedding (P=0.36), although presence of maternal or infant fever was related to increased likelihood (7-9 times greater, P≤0.04) of fecal shedding in infants of mothers with COVID-19.

Social Determinant Pathways to Hypertensive Disorders of Pregnancy Among Nulliparous U.S. Women

BACKGROUND

Hypertensive disorders of pregnancy are a leading cause of maternal morbidity and mortality in the United States and impact Black mothers at disproportionately higher rates. Hypertensive disparities among racialized groups are rooted in systemic inequalities, and we hypothesize that clinical markers of allostatic load capture embodied disparities in stressors that can link upstream social determinants of health with downstream hypertensive outcomes.

METHODS

We analyzed observational cohort data from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be (n = 6,501) and developed a structural equation model linking latent social determinants of health, longitudinal markers of allostatic load across gestation, and hypertensive pregnancy outcomes in a multigroup framework.

RESULTS

Non-Hispanic Black mothers-to-be (n = 1,155) showed higher rates of hypertensive disorders of pregnancy (32%) than non-Hispanic white women (n = 5,346, 23%). Among both groups, the social environment showed stronger direct effects on allostatic markers than via behaviorally mediated dietary, exercise, or smoking pathways. Demographic aspects of the social environment (e.g., household income, partnered status) were the most salient predictor of hypertensive risk and showed stronger effects among Black women.

CONCLUSIONS

Embodied stress rooted in the social environment is a major path driving maternal hypertensive disparities in the United States, with effects that vary across racialized groups. These pathway findings underscore the greater impact of systemic stressors relative to individual health behaviors. More comprehensive and detailed analyses of sociostructural domains are needed to identify promising avenues for policy and intervention to improve maternal health.

COVID-19 stay-at-home restrictions increase the alignment in sleep and light exposure between school days and weekends in university students

Younger adults have a biological disposition to sleep and wake at later times that conflict with early morning obligations like work and school; this conflict leads to inadequate sleep duration and a difference in sleep timing between school days and weekends. The COVID-19 pandemic forced universities and workplaces to shut down in person attendance and implement remote learning and meetings that decreased/removed commute times and gave students more flexibility with their sleep timing. To determine the impact of remote learning on the daily sleep-wake cycle we conducted a natural experiment using wrist actimetry monitors to compare activity patterns and light exposure in three cohorts of students: pre-shutdown in-person learning (2019), during-shutdown remote learning (2020), and post-shutdown in-person learning (2021). Our results show that during-shutdown the difference between school day and weekend sleep onset, duration, and midsleep timing was diminished. For instance, midsleep during school days pre-shutdown occurred 50 min later on weekends (5:14 ± 12 min) than school days (4:24 ± 14 min) but it did not differ under COVID restrictions. Additionally, we found that while the interindividual variance in sleep parameters increased under COVID restrictions the intraindividual variance did not change, indicating that the schedule flexibility did not cause more irregular sleep patterns. In line with our sleep timing results, school day vs. weekend differences in the timing of light exposure present pre- and post-shutdown were absent under COVID restrictions. Our results provide further evidence that increased freedom in class scheduling allows university students to better and consistently align sleep behavior between school days and weekends.

SARS-CoV-2 specific antibody trajectories in mothers and infants over two months following maternal infection

Infants exposed to caregivers infected with SARS-CoV-2 may have heightened infection risks relative to older children due to their more intensive care and feeding needs. However, there has been limited research on COVID-19 outcomes in exposed infants beyond the neonatal period. Between June 2020 - March 2021, we conducted interviews and collected capillary dried blood spots from 46 SARS-CoV-2 infected mothers and their infants (aged 1-36 months) for up to two months following maternal infection onset (COVID+ group, 87% breastfeeding). Comparative data were also collected from 26 breastfeeding mothers with no known SARS-CoV-2 infection or exposures (breastfeeding control group), and 11 mothers who tested SARS-CoV-2 negative after experiencing symptoms or close contact exposure (COVID- group, 73% breastfeeding). Dried blood spots were assayed for anti-SARS-CoV-2 S-RBD IgG and IgA positivity and anti-SARS-CoV-2 S1 + S2 IgG concentrations. Within the COVID+ group, the mean probability of seropositivity among infant samples was lower than that of corresponding maternal samples (0.54 and 0.87, respectively, for IgG; 0.33 and 0.85, respectively, for IgA), with likelihood of infant infection positively associated with the number of maternal symptoms and other household infections reported. COVID+ mothers reported a lower incidence of COVID-19 symptoms among their infants as compared to themselves and other household adults, and infants had similar PCR positivity rates as other household children. No samples returned by COVID- mothers or their infants tested antibody positive. Among the breastfeeding control group, 44% of mothers but none of their infants tested antibody positive in at least one sample. Results support previous research demonstrating minimal risks to infants following maternal COVID-19 infection, including for breastfeeding infants.

CHECK: Multi-level Real-World Pediatric Asthma Care Coordination: Results and Lessons Learned

OBJECTIVE

Because asthma health disparities in children remain common, innovative approaches to obtain asthma health equity are essential. Comprehensive care coordination programs may address the social determinants of health that influence these disparities. This analysis aims to ascertain if receipt of Coordination of Healthcare for Complex Kids (CHECK) program services was associated with changes in school absence, cost, healthcare utilization, and controller prescription in children with asthma.

METHODS

The CHECK program ran from December 1^st, 2014 through August 31^st, 2017. Engagement with Community Health Workers (CHW) was rolling and targeted based on risk level (low, medium or high determined by healthcare utilization). This analysis included school-aged children with asthma (n = 2,629) and sufficient Chicago Public Schools attendance data (n = 430).

RESULTS

Children engaged in CHECK were more likely to be female (p = 0.046) and to identify as Black and/or Hispanic/Latino than enrolled-only children. School absence was not different between the groups. Average total cost for engaged children was 21.3% more than enrolled-only children the first year (p = 0.027) but did not differ by the second year (p = 0.948). At baseline, 68.1% of the cohort had at least one ED visit 12-months prior to CHECK, this reduced to 49.5% post-1 and 41.9% post-2. Engaged children were 21% more likely to visit an ED (p = 0.010) and 40% more likely to have a controller.

CONCLUSIONS

CHECK program receipt was associated with reduced costs and improved healthcare utilization, and controller prescriptions. School attendance did not change. The CHECK model offers potential pathways to support low-income children with asthma.

Psychosocial and energetic factors on human female pubertal timing: a systematized review

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.g. weight, height) and psychosocial stressors (e.g. adversity, father absence) in relation to female pubertal timing. A total of 1069 non-duplicated studies were identified across five databases. Twenty studies met selection criteria for critical review following independent screening of titles, abstracts and manuscripts. Within these studies, measures indicative of rapid childhood growth were more consistently associated with earlier pubertal timing than were measures of psychosocial stress. We discuss future research directions to investigate the impact of psychosocial stress on pubertal timing more robustly, including methodological and mechanistic considerations, and contextualization of findings by socioecological environments.

Traditional and biomedical maternal and neonatal care practices in a rural Indigenous population of the Bolivian Amazon

In recent decades, Bolivia has expanded maternal and child health insurance coverage to improve access to prenatal and early life health care. Nationally, however, maternal and child health disparities persist along a rural-urban divide. Research is needed among rural populations to better understand local barriers to health care access and usage. Particularly among Indigenous populations, disparities may be compounded by differences in preferences for and access to traditional versus biomedical health care. We examined prenatal care and birth practices among Tsimane forager-farmers of El Beni, Bolivia. From 2012-2013, we interviewed 151 Tsimane mothers (0-35 months postpartum) from nine villages about birth and neonatal care practices, prenatal care, and pharmaceutical usage during labour and postpartum recovery. Results demonstrate local disparities in biomedical care usage by ease of access (e.g. proximity to market town, Spanish fluency), and maternal experience (e.g. parity and prior offspring death or miscarriage). While 59% of interviewed mothers had received at least one prenatal screening, services performed in screenings were limited. Nearly all women continue to birth at home with family assistance. Inconsistent access to health care services may be exacerbated by regional, generational, and educational disparities within the population.

Milk From Women Diagnosed With COVID-19 Does Not Contain SARS-CoV-2 RNA but Has Persistent Levels of SARS-CoV-2-Specific IgA Antibodies

Background

Limited data are available regarding the balance of risks and benefits from human milk and/or breastfeeding during and following maternal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Objective

To investigate whether SARS-CoV-2 can be detected in milk and on the breast after maternal coronavirus disease 2019 (COVID-19) diagnosis; and characterize concentrations of milk immunoglobulin (Ig) A specific to the SARS-CoV-2 spike glycoprotein receptor binding domain (RBD) during the 2 months after onset of symptoms or positive diagnostic test.

Methods

Using a longitudinal study design, we collected milk and breast skin swabs one to seven times from 64 lactating women with COVID-19 over a 2-month period, beginning as early as the week of diagnosis. Milk and breast swabs were analyzed for SARS-CoV-2 RNA, and milk was tested for anti-RBD IgA.

Results

SARS-CoV-2 was not detected in any milk sample or on 71% of breast swabs. Twenty-seven out of 29 (93%) breast swabs collected after breast washing tested negative for SARS-CoV-2. Detection of SARS-CoV-2 on the breast was associated with maternal coughing and other household COVID-19. Most (75%; 95% CI, 70-79%; n=316) milk samples contained anti-RBD IgA, and concentrations increased (P=.02) during the first two weeks following onset of COVID-19 symptoms or positive test. Milk-borne anti-RBD IgA persisted for at least two months in 77% of women.

Conclusion

Milk produced by women with COVID-19 does not contain SARS-CoV-2 and is likely a lasting source of passive immunity via anti-RBD IgA. These results support recommendations encouraging lactating women to continue breastfeeding during and after COVID-19 illness.

Birth mode and infectious morbidity risks in Qom children of Argentina

OBJECTIVES

Cesarean delivery may increase childhood infectious morbidity risks via altered birth exposures and subsequent immune, microbial, and epigenetic development. Many Latin American indigenous populations experience dual burdens of infectious and chronic diseases, and are particularly vulnerable to rising rates of cesarean delivery and associated adverse outcomes. The Qom/Toba are an indigenous population in Argentina experiencing rapid lifestyle transitions. We hypothesized that cesarean delivery would be associated with increased risk of infectious symptoms in Qom children after adjusting for gestational and nutritional factors.

METHODS

We conducted a secondary analysis of birth records and monthly anthropometric and illness data collected previously from 90 Qom children (aged 1-55 months). We tested for additive effects of birth mode on risk of gastrointestinal (GI) and respiratory illness (RI) in mixed-effects logistic regression models adjusting for child weight-for-age (WAZ), weaning, and gestational and maternal age.

RESULTS

Cesarean deliveries accounted for 46% of births and were associated with maternal age < 20 and ≥ 30 years, gestational age < 39 weeks, and prenatal complications. GI and RI risks were reduced in association with cesarean delivery, greater WAZ, weaning, maternal age ≥ 30 years, and gestational age < 39 weeks.

CONCLUSIONS

The relationship between cesarean delivery and reduced infectious risks may reflect statistical confounding with relatively rapid postnatal growth and greater adiposity. Postnatal growth trajectories may be important mediators of long-term morbidity risks associated with cesarean delivery. The frequency of cesarean deliveries among the Qom remains concerning given traditionally high rates of fertility and adolescent pregnancy.

Variation among populations in the immune protein composition of mother's milk reflects subsistence pattern

LAY SUMMARY

Adaptive immune proteins in mothers' milk are more variable than innate immune proteins across populations and subsistence strategies. These results suggest that the immune defenses in milk are shaped by a mother's environment throughout her life.

BACKGROUND AND OBJECTIVES

Mother's milk contains immune proteins that play critical roles in protecting the infant from infection and priming the infant's developing immune system during early life. The composition of these molecules in milk, particularly the acquired immune proteins, is thought to reflect a mother's immunological exposures throughout her life. In this study, we examine the composition of innate and acquired immune proteins in milk across seven populations with diverse disease and cultural ecologies.

METHODOLOGY

Milk samples (n = 164) were collected in Argentina, Bolivia, Nepal, Namibia, Philippines, Poland and the USA. Populations were classified as having one of four subsistence patterns: urban-industrialism, rural-shop, horticulturalist-forager or agro-pastoralism. Milk innate (lactalbumin, lactoferrin and lysozyme) and acquired (Secretory IgA, IgG and IgM) protein concentrations were determined using triple-quadrupole mass spectrometry.

RESULTS

Both innate and acquired immune protein composition in milk varied among populations, though the acquired immune protein composition of milk differed more among populations. Populations living in closer geographic proximity or having similar subsistence strategies (e.g. agro-pastoralists from Nepal and Namibia) had more similar milk immune protein compositions. Agro-pastoralists had different milk innate immune protein composition from horticulturalist-foragers and urban-industrialists. Acquired immune protein composition differed among all subsistence strategies except horticulturist-foragers and rural-shop.

CONCLUSIONS AND IMPLICATIONS

Our results reveal fundamental variation in milk composition that has not been previously explored in human milk research. Further study is needed to understand what specific aspects of the local environment influence milk composition and the effects this variation may have on infant health outcomes.

Timing of pubertal growth and menarche in indigenous Qom girls of Argentina

BACKGROUND

Pubertal timing is in part mediated by environmental factors, with greater energy availability often associated with earlier or more rapid development. Many indigenous populations are undergoing socioeconomic change that may affect pubertal development and related health risks, necessitating fundamental longitudinal research on growth and development in these populations.

AIM

Growth velocity and time to menarche among peri-urban indigenous Qom (Toba) girls in Argentina are described.

SUBJECTS AND METHODS

From 2011-2015, monthly anthropometrics and menstrual status were collected from 61 Qom girls aged 7-14. Growth velocity curves were generated using the 'Super-imposition by translation and rotation' (SITAR) method. Median time to menarche was estimated by Kaplan-Meier survival analysis.

RESULTS

Mean ages at peak height, weight and BMI velocity were estimated at 10.8, 10.5 and 10.7 years and median age at menarche at 11.6 years (95% CI = 11.4-11.9). At menarche, 45% of girls were overweight or obese and only one participant was short-statured by international standards.

CONCLUSION

Qom participants in this study exhibit relatively fast pubertal development as compared to other Latin American indigenous populations studied previously by others. Genetic and environmental factors influencing body size, diet and/or activity levels should be investigated further in this population.

Redefining the therapeutic objective in psoriatic patients candidates for biological therapy

The advances in psoriasis management currently allow achieving a good control of the disease. In particular, with the latest developed molecules, available evidence suggests that it is possible to pose an ambitious therapeutic goal, such as a Dermatology Life Quality Index 0/1, a Physician Global Assessment 0/1, or a Psoriasis Area and Severity Index 90/100 response. However, patients often fail to achieve the complete clearance of their cutaneous lesions or the improvement of disease factors that impair their quality of life. To optimize the treatment of psoriasis, it is not enough to define precisely the therapeutic objective, but also to adapt the therapeutic strategy to make the necessary modifications in case of not achieving it at the time point (at the end of the induction phase, or every 3-6 months) to be agreed with the patient (the so-called treat-to-target approach). In the present report, based on the Delphi methodology, 11 dermatologists from the Spanish Psoriasis Group addressed key issues that could be involved in the achievement and maintenance of the therapeutic goals of patients with moderate to severe psoriasis. The document provides 27 consensus statements intended to support clinical decision-making by healthcare professionals for patients who might be candidates to receive biologic therapy.

Conflict or congruence? Maternal and infant-centric factors associated with shorter exclusive breastfeeding durations among the Tsimane

Six months of exclusive breastfeeding (EBF) is considered optimal for infant health, though globally most infants begin complementary feeding (CF) earlier-including among populations that practice prolonged breastfeeding. Two frameworks for understanding patterns of early CF emerge in the literature. In the first, maternal and infant needs trade-off, as "maternal-centric" factors-related to time and energy demands, reproductive investment, cultural influences, and structural barriers- favor supplanting breastfeeding with earlier and increased CF. A second framework considers that "infant-centric" factors-related to infant energetic needs-favor CF before six months to supplement breastfeeding. We apply these two frameworks in examining early CF among the Tsimane-a high-fertility, high-mortality, forager-horticulturalist population residing in the Bolivian Amazon. Data were collected from a mixed-longitudinal sample of 161 Tsimane mother-infant pairs from August 2012-April 2013. Tsimane mothers generally reported introducing CF because of perceived infant needs. However, CF is introduced with continued intensive breastfeeding, and generally coupled with premastication. Risks of earlier CF relative to the minimum hazard (estimated at 5 births) were elevated for lower and higher parity mothers, but were significantly greater only after 9 births. Seventeen percent of mothers reported introducing CF because of low milk supply. Introducing CF because of low milk was most common from 0 to 3 months of age and among higher parity mothers, which may reflect physiological constraints. Maternal reproductive trade-offs and perceived infant needs may help explain the low prevalence of EBF to six months among other populations in which breastfeeding is not structurally or culturally constrained.

Clinical Pharmacogenetics Implementation Consortium Guidelines for HLA-B Genotype and Abacavir Dosing: 2014 update

The Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for HLA-B Genotype and Abacavir Dosing were originally published in April 2012. We reviewed recent literature and concluded that none of the evidence would change the therapeutic recommendations in the original guideline; therefore, the original publication remains clinically current. However, we have updated the Supplementary Material online and included additional resources for applying CPIC guidelines to the electronic health record. Up-to-date information can be found at PharmGKB (http://www.pharmgkb.org).

Natural disease course and genotype-phenotype correlations in Complex I deficiency caused by nuclear gene defects: what we learned from 130 cases

Mitochondrial complex I is the largest multi-protein enzyme complex of the oxidative phosphorylation system. Seven subunits of this complex are encoded by the mitochondrial and the remainder by the nuclear genome. We review the natural disease course and signs and symptoms of 130 patients (four new cases and 126 from literature) with mutations in nuclear genes encoding structural complex I proteins or those involved in its assembly. Complex I deficiency caused by a nuclear gene defect is usually a non-dysmorphic syndrome, characterized by severe multi-system organ involvement and a poor prognosis. Age at presentation may vary, but is generally within the first year of life. The most prevalent symptoms include hypotonia, nystagmus, respiratory abnormalities, pyramidal signs, dystonia, psychomotor retardation or regression, failure to thrive, and feeding problems. Characteristic symptoms include brainstem involvement, optic atrophy and Leigh syndrome on MRI, either or not in combination with internal organ involvement and lactic acidemia. Virtually all children ultimately develop Leigh syndrome or leukoencephalopathy. Twenty-five percent of the patients died before the age of six months, more than half before the age of two and 75 % before the age of ten years. Some patients showed recovery of certain skills or are still alive in their thirties . No clinical, biochemical, or genetic parameters indicating longer survival were found. No clear genotype-phenotype correlations were observed, however defects in some genes seem to be associated with a better or poorer prognosis, cardiomyopathy, Leigh syndrome or brainstem lesions.

Fatty acid composition in the mature milk of Bolivian forager-horticulturalists: controlled comparisons with a US sample

Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6-82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational stage to samples from a US milk bank, and analysed concurrently for FA composition by gas-liquid chromatography. We compared milk FA composition between Tsimane (n = 35) and US (n = 35) mothers, focusing on differences in LCPUFA percentages that may be due to population-typical dietary patterns. Per total FAs, the percentages of AA, DHA, total n-3 and total n-6 LCPUFA were significantly higher among Tsimane mothers. Mean percentages of 18:2n-6 (linoleic acid) and trans FAs were significantly higher among US mothers. Tsimane mothers' higher milk n-3 and n-6 LCPUFA percentages may be due to their regular consumption of wild game and freshwater fish, as well as comparatively lower intakes of processed foods and oils that may interfere with LCPUFA synthesis.

Evidence for a peak shift in a humoral response to helminths: age profiles of IgE in the Shuar of Ecuador, the Tsimane of Bolivia, and the U.S. NHANES

BACKGROUND

The peak shift model predicts that the age-profile of a pathogen's prevalence depends upon its transmission rate, peaking earlier in populations with higher transmission and declining as partial immunity is acquired. Helminth infections are associated with increased immunoglobulin E (IgE), which may convey partial immunity and influence the peak shift. Although studies have noted peak shifts in helminths, corresponding peak shifts in total IgE have not been investigated, nor has the age-patterning been carefully examined across populations. We test for differences in the age-patterning of IgE between two South American forager-horticulturalist populations and the United States: the Tsimane of Bolivia (n=832), the Shuar of Ecuador (n=289), and the U.S. NHANES (n=8,336). We then examine the relationship between total IgE and helminth prevalences in the Tsimane.

METHODOLOGY/PRINCIPAL FINDINGS

Total IgE levels were assessed in serum and dried blood spots and age-patterns examined with non-linear regression models. Tsimane had the highest IgE (geometric mean =8,182 IU/ml), followed by Shuar (1,252 IU/ml), and NHANES (52 IU/ml). Consistent with predictions, higher population IgE was associated with steeper increases at early ages and earlier peaks: Tsimane IgE peaked at 7 years, Shuar at 10 years, and NHANES at 17 years. For Tsimane, the age-pattern was compared with fecal helminth prevalences. Overall, 57% had detectable eggs or larva, with hookworm (45.4%) and Ascaris lumbricoides (19.9%) the most prevalent. The peak in total IgE occurred around the peak in A. lumbricoides, which was associated with higher IgE in children <10, but with lower IgE in adolescents.

CONCLUSIONS

The age-patterning suggests a peak shift in total IgE similar to that seen in helminth infections, particularly A. lumbricoides. This age-patterning may have implications for understanding the effects of helminths on other health outcomes, such as allergy, growth, and response to childhood vaccination.

Living donor liver transplantation: usefulness of hemostatic and prothrombotic screening in potential donors

Bleeding and thrombosis are serious complications of living donor liver transplantation (LDLT). The aim of this paper was to describe the results of a screening for coagulation disorders, including for thrombophilic factors, in potential living liver graft donors and to evaluate thrombotic and bleeding events in donors and recipients, during and after the procedure. From January 2001 to January 2007, 41 LDLTs were performed at our institution. We performed systematic screening for bleeding or prothrombotic states among 188 potential donors, 38 (20.2%) of whom showed at least one abnormality. We rejected potential donors with factor V Leiden, prothrombin mutation G20210A, and deficiencies in anticoagulant proteins (protein C, protein S, and antithrombin) or coagulation factors. Bleeding and thrombotic events in donors and recipients of the 41 LDLTs were evaluated during 7 days to 70 months follow-up. No major bleeding events were detected in the donors. Neither donor nor recipient experienced venous thrombosis or pulmonary embolism. Among all recipients, six suffered hepatic artery thrombosis including five in the first month probably related to surgery. Deep venous thrombosis and pulmonary embolism are well-known complications of hepatic surgery; Prothrombotic abnormalities in the donor can be transmitted to the recipient, leading to increased risk of serious postoperative events. Although the cost-effectiveness is not definitely established, we recommend systematic screening for hemostatic and prothrombotic disorders to prevent more morbidity of a procedure that already has high risks of bleeding and thrombosis.

The use of fluorescent probes in pharmaceutical analysis

Even though many pharmaceuticals show native fluorescence, there is also an important group of compounds which is not fluorescent. A main object of studies is to make them fluorescent, principally by using fluorescent probes through derivatisation reactions. An account of the fluorescent probes more widely used for the determination of drugs and related compounds is presented in this review paper. A wide variety of fluorescent probes is described on the basis of their ability to react specifically with various functional groups. Attention is focused on derivatisation reactions used in spectrofluorimetry and chromatographic techniques (HPLC, TLC) with fluorimetric detection. The review covers only those fluorescent probes whose use involves a chemical reaction with the analyte, and not those methods that involve physico-chemical interactions such as sensitised or charge transfer processes. Many of these derivatisation reactions have been widely used in the detection of primary and secondary amines. Reagents such as dansyl chloride, fluorescamine, o-phtalaldehyde are very well known. Other reagents have also been developed for other functional groups, for example dansyl hydrazine for compounds with a carbonyl function or 4-bromomethyl-7-methoxy-coumarin for acidic compounds . Acid chlorides such as dansyl chloride may also react with different functional groups carrying active hydrogens as do phenols. The use and development of new fluorescent probes in pharmaceutical analysis is a subject for further studies.

Novel mutations in patients with McArdle disease by analysis of skeletal muscle mRNA

OBJECTIVE

To identify pathogenic mutant alleles of the PYGM gene in "genetic manifesting heterozygous" patients with McArdle disease-that is, those in whom we could only find a sole mutant allele by genomic DNA analysis.

METHODS

We studied four unrelated patients. PCR-RFLP, gene sequencing, and muscle cDNA analysis were performed to search for mutations in the PYGM gene. The effects of the mutations were evaluated by in silico analysis, and gene expression was assessed by real-time polymerase chain reaction (PCR).

RESULTS

Patient 1 was a compound heterozygous for the p.G205S missense mutation and for a novel "in frame" mutation, p.Q176_M177insVQ, resulting from a retention of six nucleotides from the 3'-end sequence of intron 4. Patient 2 was heterozygous for the common nonsense mutation p.R50X, and for a 1094 bp, c.1969+214_2177+369del mutation, spanning from intron 16 to intron 17 sequences. Furthermore, mRNA expression level was dramatically reduced consistent with nonsense mediated decay. Patient 3 was heterozygous for the p.R50X substitution, and patient 4 was heterozygous for the relatively common private Spanish mutation p.W798R. These two patients harboured a heterozygous exonic synonymous variant, p.K215K. Quantification of gene transcripts in patient 3 revealed a drastic decrease in the relative expression of the gene, which strongly supports the possibility of nonsense mediated decay.

CONCLUSIONS

Our results indicate that skeletal muscle cDNA studies in "genetic manifesting heterozygous" patients with McArdle disease are prone to identify their second mutant allele.

Genotype distributions in top-level soccer players: a role for ACE?

We determined the genotype and allelic frequency of several genetic polymorphisms (ACE I/D, GDF-8K153R [and also E164K, P198A and I225T] and AMPD1 C34T) that are candidates to influence sports performance in a group of 54 male professional soccer players. Their results were compared with those of elite endurance male athletes (52 runners) and 123 sedentary, healthy men (controls). We found statistical significance for the ACE ID (chi (2)((2))=8.176, P=0.017) and II genotypes (chi(2)((2))=16.137, P<0.001) with a higher and lower frequency of ID ( P=0.005) and II (P<0.001), respectively, in soccer players than in endurance runners. Statistical significance was also reached for AMPD1 (with a higher frequency of the CT genotype in soccer players than in runners [chi(2)((2))=7.538, P=0.006]) but not for GDF-8 K153R. Since the ACE II genotype is associated with improved potential for endurance performance but with decreased training gains in muscle mass and strength, these findings together with previous results support the notion that elite soccer players tend to have a power/strength oriented genotype.

Can patients with McArdle's disease run?

Patients with McArdle's disease commonly adopt a sedentary lifestyle. This sedentary behaviour, however, usually worsens the limited exercise capacity of these patients. Although eccentric muscle work can be associated with rhabdomyolysis, supervised eccentric training with gradually increasing loads has important advantages compared with conventional concentric work, particularly for patients with a poor cardiorespiratory system. We report the beneficial effects (particularly, increased VO(2peak) (from 14.6 to 30.8 ml/kg/min) and increased gross muscle efficiency (from 13.8% to 17.2%)) induced by a supervised aerobic training programme of 7 months duration including 3-4 running sessions (< or =60 min/session) per week in a 38-year-old patient. These preliminary data suggest the potential therapeutic value of this type of exercise in these patients.

Exercise capacity in a 78 year old patient with McArdle's disease: it is never too late to start exercising

The case is reported of a 78 year old man with McArdle's disease and a history of treated coronary heart disease. Despite the pre-exercise administration of sucrose allowing the patient to exercise with normal physiological responses, and without typical McArdle's symptoms or biochemical evidence of muscle damage, his exercise capacity was very low (V(O2)peak = 10.7 ml/min/kg), probably attributable to his lifetime of sedentary living. The data suggest that, with pre-exercise sucrose administration, such patients may be candidates for systematic reconditioning, which may improve functional capacity and quality of life.

Mobilisation of mesenchymal cells into blood in response to skeletal muscle injury

Mesenchymal cells recruited to damaged tissues must circulate through the bloodstream. The absolute numbers of circulating mesenchymal stem cells (cMSCs) in two different models of acute and chronic skeletal muscle injury were determined. cMSCs were present in significantly higher numbers in both models than in healthy controls. These results support the hypothesis that MSCs are mobilised into the bloodstream after skeletal muscle tissue damage. These two models (acute and chronic) would be of value in the search for molecular mediators of mobilisation of MSCs into the circulation.

Does the C34T Mutation in AMPD1 Alter Exercise Capacity in the Elderly?

Ageing does affect functional capacity through several changes at the peripheral muscle level that impair the muscles capacity to produce energy and generate force. The skeletal muscle-specific isoform of AMP deaminase (AMPD) plays an important regulatory role in muscle metabolism and in determining energy charge. Since nearly 20 % of the general Caucasian population is heterozygous (CT) for the most common C34T mutation of the gene (AMPD1) encoding for this enzyme, it would be worthwhile to study if such a condition further increases the effects of ageing. Twenty-one women (61 - 80 yrs) served as subjects, and depending on the results of previous genotyping, were assigned to a group with the C34T mutation (heterozygous; n=4; mean+/-SEM age: 71+/-1 yrs) or with no mutation (n=17; 68+/-1 yrs). Several indices of maximal (peak oxygen uptake [V.O (2 peak)], peak power output) and submaximal endurance performance (ventilatory threshold, mechanical efficiency) and functional tests (one-mile walk test and a specific test of lower-body functional performance [sit-stand test]) were compared between the two groups. No significant differences were found in exercise capacity between both groups, e. g. V.O (2 peak) of 19.1+/-1.0 vs. 20.1+/-1.9 ml . kg (-1) . min (-1), V.O (2) at the VT of 11.9+/-0.6 vs. 12.9+/-1.0 ml . kg (-1) . min (-1), or time to complete the one-mile walk test (951+/-18 s vs. 962+/-61 s) and sit-stand test (9.9+/-0.2 vs. 9.2+/-0.2) (no mutation vs. C34T mutation, respectively). Although more research is necessary, it seems that the C34T mutation of the AMPD1, at least in heterozygous individuals, does not affect functional capacity in the elderly.

C34T mutation of the AMPD1 gene in an elite white runner

The case is reported of an elite, male, white endurance runner (28 years of age), who is one of the best non-African runners in the world despite carrying the C34T mutation in the gene (AMPD1) that encodes the skeletal muscle specific isoform of AMP deaminase, an enzyme that plays an important role in muscle metabolism. The frequency of the mutant allele in sedentary white people is 8-11%. Previous research has shown that this mutation, at least in homozygotes, can impair the exercise capacity of untrained people and their trainability. The maximum oxygen uptake of the study subject was exceptionally high (83.6 ml/kg/min), whereas his ammonia and lactate concentrations at high submaximal running speeds were lower than those of other world class runners who are not carriers of the mutation. The partial metabolic deficiency of the study subject is possibly compensated for by his exceptionally favourable anthropometric characteristics (body mass index 18.2 kg/m2).

Applying a moving total mortality count to the cities in the NMMAPS database to estimate the mortality effects of particulate matter air pollution

OBJECTIVES

To apply a new method for estimating the association between daily ambient particulate matter air pollution (PM) and daily mortality to data from over 100 United States cities contained in the National Morbidity, Mortality, and Air Pollution Study (NMMAPS) database and to see whether the results from the 90 cities NMMAPS analysis are robust to this different modelling approach. This new method has recently been shown to provide improved estimates for the association between PM and daily mortality when every-day PM data are unavailable. It avoids the need for selecting a lag of PM at which the mortality effects of PM are to be investigated.

METHODS

With the aid of analytical methods and databases developed for NMMAPS, Poisson log linear models controlling for long term trends and weather effects were used to estimate the association between PM and mortality for cities in the NMMAPS database using the new method. A two stage Bayesian hierarchical model was then used to combine city specific estimates to form a national average PM mortality effect estimate.

RESULTS

A 10 microg/m3 increase in PM was associated with a 0.12% increment in total mortality and a 0.17% increment in cardiovascular and respiratory mortality. These results are consistent with those found in the NMMAPS analysis.

CONCLUSIONS

There is a statistically significant association between short term changes in PM and mortality on average for the cities contained in the NMMAPS database. These findings are further evidence that this widespread pollutant adversely affects public health.

Tumour dose enhancement using modified megavoltage photon beams and contrast media

This study examines the magnitude of tumour dose enhancement achieved by injection of gadolinium or iodine contrast media (CM) and treatment using modified x-ray photon spectra from linear accelerators. Monte Carlo modelling of the linear accelerator and patient geometry was used to explore the effect of removing the flattening filter for various beam qualities and the resultant effect on dose enhancement. In addition, ionization measurements were conducted to observe dose enhancement within a phantom containing CM. Simulation results indicate that for flattened 6-24 MV photon beams and realistic CM tumour concentrations, the dose enhancement remains below 5%. However, if the flattening filter is removed, dose enhancement is increased significantly. For a 30 mg ml(-1) gadolinium CM tumour concentration, for example, 8.4%, 10.8%, 13.7% and 23.1% dose enhancements are achieved for 18 MV, 6 MV, 4 MV and 2 MV unflattened beams, respectively. In contrast to the phototherapy technique, which uses the orthovoltage beam from a modified CT scanner to achieve dose enhancement, all unflattened spectra preserve the dose build-up at the surface, and thus the skin and bone are spared.

Economic considerations for the adoption of transgenic crops: the case of bt corn

Biotechnology is offering farmers new crop production opportunities and challenges. Prior to selecting a transgenic variety, farmers must consider the cost of the technology fee, possible yield drag, potential pest infestations, possible reductions in pesticide costs, refuge requirements to minimize the development of insect resistance, and adjustments in cultural practices. Moreover, crop segregation in the field, storage, and shipment may be necessary to capture potential price premiums for nontransgenic varieties. As farmers consider these various production and marketing factors, they find that Bt corn is a more profitable control method for European corn borer in the Western Corn Belt relative to the Eastern Corn Belt. This is primarily due to higher infestation probabilities in the Western Corn Belt, coupled with greater demand for manufacturing and export uses in the Eastern Corn Belt where several buyers do not accept transgenic corn.

Thyroid hormone regulates oxidative phosphorylation in the cerebral cortex and striatum of neonatal rats

We have previously shown that thyroid hormone (T(3)) regulates mitochondrial gene expression, morphology and transmembrane potential in the developing brain. Here, we have analysed the effect of thyroid hormone on mitochondrial function in different brain regions. For this purpose we have determined, in control, hypothyroid and T(3)-treated hypothyroid neonatal rats, the rate of oxidative phosphorylation in isolated mitochondria and the activity of the respiratory complexes in tissue homogenates. Our results showed a decrease in oxidative phosphorylation rate (only in the presence of NADH-generating substrates) and mitochondrial complexes I and III activity in the cerebral cortex and striatum of hypothyroid neonates, but not in the other areas analysed (hippocampus, cerebellum, thalamus, mid brain and brain stem). In parallel with mitochondrial activity, the levels of mitochondrially encoded transcripts were decreased only in the cerebral cortex and striatum of hypothyroid rats. The administration of T(3) corrected all these parameters. In summary, this study showed a down-regulation of mitochondrial gene expression accompanied by a decrease in mitochondrial activity in the cerebral cortex and striatum of developing hypothyroid neonatal rats.

N-linked glycosylation sites adjacent to and within the V1/V2 and the V3 loops of dualtropic human immunodeficiency virus type 1 isolate DH12 gp120 affect coreceptor usage and cellular tropism

The envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) is extensively glycosylated, containing approximately 23 asparagine (N)-linked glycosylation sites on its gp120 subunit. In this study, specific glycosylation sites on gp120 of a dualtropic primary HIV-1 isolate, DH12, were eliminated by site-directed mutagenesis and the properties of the resulting mutant envelopes were evaluated using a recombinant vaccinia virus-based cell-to-cell fusion assay alone or in the context of viral infections. Of the glycosylation sites that were evaluated, those proximal to the V1/V2 loops (N135, N141, N156, N160) and the V3 loops (N301) of gp120 were functionally critical. The glycosylation site mutations near the V1/V2 loop compromised the use of CCR5 and CXCR4 equally. In contrast, a mutation within the V3 loop preferentially inhibited the usage of CCR5; although this mutant protein completely lost its CCR5-dependent fusion activity, it retained 50% of the wild-type fusion activity with CXCR4. The replication of a virus containing this mutation was severely compromised in peripheral blood mononuclear cells, MT-4 cells, and primary monocyte-derived macrophages. A revertant virus, which acquired second site changes in the V3 loop that resulted in an increase in net positive charge, was isolated. The revertant virus fully recovered the usage of CXCR4 but not of CCR5, thereby altering the tropism of the parental virus from dualtropic to T-tropic. These results suggest that carbohydrate moieties near the V1/V2 and the V3 loops play critical roles in maintaining proper conformation of the variable loops for optimal interaction with receptors. Our results, combined with those of previously reported studies, further demonstrate that the function of individual glycans may be virus isolate dependent.

Polyvalent envelope glycoprotein vaccine elicits a broader neutralizing antibody response but is unable to provide sterilizing protection against heterologous Simian/human immunodeficiency virus infection in pigtailed macaques

The great difficulty in eliciting broadly cross-reactive neutralizing antibodies (NAbs) against human immunodeficiency virus type 1 (HIV-1) isolates has been attributed to several intrinsic properties of their viral envelope glycoprotein, including its complex quaternary structure, extensive glycosylation, and marked genetic variability. Most previously evaluated vaccine candidates have utilized envelope glycoprotein from a single virus isolate. Here we compare the breadth of NAb and protective immune response following vaccination of pigtailed macaques with envelope protein(s) derived from either single or multiple viral isolates. Animals were challenged with Simian/human immunodeficiency virus strain DH12 (SHIV(DH12)) following priming with recombinant vaccinia virus(es) expressing gp160(s) and boosting with gp120 protein(s) from (i) LAI, RF, 89.6, AD8, and Bal (Polyvalent); (ii) LAI, RF, 89.6, AD8, Bal, and DH12 (Polyvalent-DH12); (iii) 89.6 (Monovalent-89.6); and (iv) DH12 (Monovalent-DH12). Animals in the two polyvalent vaccine groups developed NAbs against more HIV-1 isolates than those in the two monovalent vaccine groups (P = 0.0054). However, the increased breadth of response was directed almost entirely against the vaccine strains. Resistance to SHIV(DH12) strongly correlated with the level of NAbs directed against the virus on the day of challenge (P = 0.0008). Accordingly, the animals in the Monovalent-DH12 and Polyvalent-DH12 vaccine groups were more resistant to the SHIV(DH12) challenge than the macaques immunized with preparations lacking a DH12 component (viz. Polyvalent and Monovalent-89.6) (P = 0.039). Despite the absence of any detectable NAb, animals in the Polyvalent vaccine group, but not those immunized with Monovalent-89.6, exhibited markedly lower levels of plasma virus than those in the control group, suggesting a superior cell-mediated immune response induced by the polyvalent vaccine.

Recent economic evaluations of antenatal screening: a systematic review and critique

A systematic review of recent economic evaluations of antenatal screening was conducted. Relevant studies were identified from a number of sources including computerised databases, bibliographies of economic evaluations, and searches of unpublished manuscripts. Each study identified by the literature searches was categorised on the basis of its title and abstract. Studies considered relevant to the systematic review were obtained from libraries. The methodology, results, and policy implications of studies categorised as economic evaluations upon full review were documented. A total of 566 studies were identified by the literature searches, 41 of which were categorised as economic evaluations upon full review. The economic evaluations covered a range of antenatal screening practices, aimed mainly at the prevention of infectious diseases and fetal anomalies. The review highlighted the poor methodological quality of the bulk of economic evaluations of antenatal screening. The study design, data collection methods, and analysis and interpretation of results frequently violated methodological guidelines adopted by health economists. The review also highlighted the narrow definition of benefits adopted by this body of literature, with most studies reporting outcomes in terms of cases detected, cases of particular disorders prevented or, most often, costs averted. The conclusions arrived at differed by area of antenatal screening. There appeared to be clear economic arguments in favour of some forms of antenatal screening, for example, triple test screening for Down's syndrome. Other economic evaluations pertained to specific locations, which suggests that the results may not necessarily be generalizable to different settings. For all areas of antenatal screening, an updating of published economic evaluations may be required to account for evolving economic, epidemiological, and clinical effectiveness evidence.

Macrophage are the principal reservoir and sustain high virus loads in rhesus macaques after the depletion of CD4+ T cells by a highly pathogenic simian immunodeficiency virus/HIV type 1 chimera (SHIV): Implications for HIV-1 infections of humans

The highly pathogenic simian immunodeficiency virus/HIV type 1 (SHIV) chimeric virus SHIV(DH12R) induces a systemic depletion of CD4(+) T lymphocytes in rhesus monkeys during the initial 3-4 weeks of infection. Nonetheless, high levels of viral RNA production continue unabated for an additional 2-5 months. In situ hybridization and immunohistochemical analyses revealed that tissue macrophage in the lymph nodes, spleen, gastrointestinal tract, liver, and kidney sustain high plasma virus loads in the absence of CD4(+) T cells. Quantitative confocal immunofluorescence analysis indicated that greater than 95% of the virus-producing cells in these tissues are macrophage and less than 2% are T lymphocytes. Interestingly, the administration of a potent reverse transcriptase inhibitor blocked virus production during the early T cell phase but not during the later macrophage phase of the SHIV(DH12R) infection. When interpreted in the context of HIV-1 infections, these results implicate tissue macrophage as an important reservoir of virus in vivo. They become infected during the acute infection, gradually increase in number over time, and can be a major contributor to total body virus burden during the symptomatic phase of the human infection.

Identifying priority patients for coronary angiography

We conducted an open observational study with blinded endpoint evaluation to validate the use of the Duke treadmill score in identifying patients likely to require coronary intervention. We studied 101 consecutive patients referred for coronary angiography from a cardiology clinic. All patients had a Bruce protocol exercise test. A 70% stenosis was regarded as significant. Patients were referred for percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) surgery, if indicated. The Duke score was calculated as follows: exercise time (min) - (5 x ST segment deviation [mm]) - (4 x angina index [text]). Patients were classified into low, medium and high risk. The patients at high risk are more likely to have a significant stenosis (53/58 vs 30/43: p = 0.01 [OR 4.59 95% CI 1.34-16.6]) and require CABG or PTCA (47/58 vs 16/43: p < 0.001 [OR 7.21 95% CI 2.69-19.8]) than those at medium/low risk. Multiple logistic regression analysis, including ST segment depression, exercise time and symptoms shows that the score independently predicts a significant stenosis (p = 0.002) and the need for coronary intervention (p = 0.001). Introducing the score can help to identify those patients who need priority investigation.

Associations between alcohol consumption and insulin sensitivity and cardiovascular disease risk factors: the Insulin Resistance and Atherosclerosis Study

OBJECTIVE

Light-to-moderate alcohol consumption has been associated with reduced cardiovascular disease (CVD) mortality, which may be explained by increased insulin sensitivity (SI) and an improved lipoprotein and blood pressure profile. Prior research has shown improved SI with light-to-moderate alcohol intake even though somewhat imprecise measures of SI were used.

RESEARCH DESIGN AND METHODS

Relationships between alcohol use and SI and CVD risk factors were assessed in a cross-sectional analysis of 1,196 white, African-American, and Hispanic men and women from the Insulin Resistance and Atherosclerosis Study (IRAS). Five categories of previous-year alcohol use (never, <0.5 drinks/day, 0.5-0.99 drinks/day, 1-2.99 drinks/day, and > or =3 drinks/day) and log SI + 1 (frequently sampled intravenous glucose tolerance test with Bergman minimal model analysis), log fasting insulin, log triglycerides, HDL cholesterol, and systolic/diastolic blood pressure were examined using analysis of variance.

RESULTS

Univariate analysis showed an inverse U-shaped relationship between SI and alcohol intake, with a peak at the 0.5-0.99 drinks/day category. A U-shaped relationship was observed between fasting insulin and the lipid and blood pressure measures. After adjustment for demographic (clinic, sex, ethnicity, age), lifestyle (smoking, dietary energy/fat intake, physical activity), and physical (BMI, waist circumference) variables, the alcohol/insulin association was attenuated, but the association with lipids and blood pressure remained for high-intake categories.

CONCLUSIONS

These data suggest that the enhanced SI associated with light-to-moderate alcohol consumption may be a function solely of a BMI and central adiposity profile more favorable to higher SI.

Identification of gp120 regions targeted by a highly potent neutralizing antiserum elicited in a chimpanzee inoculated with a primary human immunodeficiency virus type 1 isolate

We have previously reported that a chimpanzee infected with a primary human immunodeficiency virus type 1 (HIV-1) isolate (HIV-1(DH12)) developed an extremely potent virus-neutralizing antibody. Immunoglobulin G purified from this animal conferred sterilizing immunity following passive transfer to macaques which were subsequently challenged with simian immunodeficiency virus/HIV-1 chimeric virus strain DH12. In addition to being highly strain specific, the chimpanzee antiserum did not bind to the V3 loop peptide of HIV-1(DH12), nor did it block the interaction of gp120 with the CD4 receptor. When neutralization was examined in the context of virus particles carrying chimeric envelope glycoproteins, the presence of all five hypervariable regions (V1 to V5) was required for optimal neutralization. Virions bearing chimeric gp120 containing the V1-V2 and V4 regions of HIV-1(DH12) could also be neutralized, but larger quantities of the chimpanzee antiserum were needed to block infection. These results indicate that the HIV-1 gp120 epitope(s) targeted by the chimpanzee antiserum is highly conformational, involving surface elements contributed by all of the hypervariable domains of the envelope glycoprotein.

Short- and long-term clinical outcomes in rhesus monkeys inoculated with a highly pathogenic chimeric simian/human immunodeficiency virus

A highly pathogenic simian/human immunodeficiency virus (SHIV), SHIV(DH12R), isolated from a rhesus macaque that had been treated with anti-human CD8 monoclonal antibody at the time of primary infection with the nonpathogenic, molecularly cloned SHIV(DH12), induced marked and rapid CD4(+) T cell loss in all rhesus macaques intravenously inoculated with 1.0 50% tissue culture infective dose (TCID(50)) to 4.1 x 10(5) TCID(50)s of virus. Animals inoculated with 650 TCID(50)s of SHIV(DH12R) or more experienced irreversible CD4(+) T lymphocyte depletion and developed clinical disease requiring euthanasia between weeks 12 and 23 postinfection. In contrast, the CD4(+) T-cell numbers in four of five monkeys receiving 25 TCID(50)s of SHIV(DH12R) or less stabilized at low levels, and these surviving animals produced antibodies capable of neutralizing SHIV(DH12R). In the fifth monkey, no recovery from the CD4(+) T cell decline occurred, and the animal had to be euthanized. Viral RNA levels, subsequent to the initial peak of infection but not at peak viremia, correlated with the virus inoculum size and the eventual clinical course. Both initial infection rate constants, k, and decay constants, d, were determined, but only the latter were statistically correlated to clinical outcome. The attenuating effects of reduced inoculum size were also observed when virus was inoculated by the mucosal route. Because the uncloned SHIV(DH12R) stock possessed the genetic properties of a lentivirus quasispecies, we were able to assess the evolution of the input virus swarm in animals surviving the acute infection by monitoring the emergence of neutralization escape viral variants.

Vaginal clindamycin and oral metronidazole for bacterial vaginosis: a randomized trial

OBJECTIVE

To compare the efficacy and safety of clindamycin vaginal ovules with oral metronidazole for treatment of bacterial vaginosis.

METHODS

Women with bacterial vaginosis received either 100-mg ovules of clindamycin (intravaginally for 3 consecutive days) plus placebo capsules (orally twice daily for 7 days) or metronidazole 500 mg (two 250-mg capsules orally twice daily for 7 days) plus placebo ovules (intravaginally for 3 consecutive days). The sample was determined prospectively to provide a probability of.84 of correctly concluding that the rate of success for clindamycin is not more than 15% less than the expected 75% success rate for metronidazole. Clinical outcome was determined on the basis of vaginal fluid amine odor and clue cells.

RESULTS

Of the 399 patients enrolled, 233 could be evaluated for efficacy. Of those, 77 (68.1%) of 113 patients were cured with clindamycin, compared with 80 (66. 7%) of 120 who were cured with metronidazole (95% confidence interval -10.6%, 13.4%; P =.810). Treatment-related adverse events were reported more frequently in the metronidazole treatment group. Systemic symptoms, such as nausea and taste perversion, accounted for most of the difference between groups.

CONCLUSION

A 3-day regimen of clindamycin, given as intravaginal ovules, was as effective as and better tolerated than a 7-day regimen of oral metronidazole 500 mg, given twice daily, for treatment of bacterial vaginosis.

Higher western blot immunoreactivity of glycoprotein 120 from R5 HIV type 1 isolates compared with X4 and X4R5 isolates

The envelope glycoprotein of human immunodeficiency virus 1 (HIV-1) plays important roles in viral life cycle and pathogenesis. Understanding the immune responses the protein elicits during the course of a viral infection in patients is important in designing an effective vaccine candidate against the virus or for better diagnosis of the disease. In this study, we report that gp120 of R5 isolates have higher Western blot (WB) immunoreactivity to antibodies elicited against the protein in virus-infected human patients compared with that of X4 and X4R5 isolates. Analyses of WB immunoreactivity of chimeric gp120s constructed between R5 (AD8) and X4R5 (DH12) HIV-1 isolates indicate that there are complex tertiary interdomain interactions even after a complete denaturation of the protein. Our data suggest that the determinant(s) responsible for the high WB immunoreactivity might be present in all gp120s, but are accessible to antibodies only for R5 gp120s in the WB assay. The V1/V2 and/or V3 regions of X4 and X4R5 gp120s likely interfere with either the formation or surface exposure of the WB immunoreactive determinant. Supplementing HIV-1 WB diagnosis kits with purified R5 gp120 could improve their sensitivity and facilitate earlier diagnosis of virus infection.

Quantification of thymic function by measuring T cell receptor excision circles within peripheral blood and lymphoid tissues in monkeys

The thymus is the primary organ responsible for the production of mature TCR alpha / beta T cells. Quantification of a DNA excision circle that is produced during TCR rearrangement, termed a signal joint TCR rearrangement excision circle (sjTREC) can be used as a measure of thymic function. Here sjTREC measurement has been applied to two monkey species used as animal models of human disease, rhesus macaques (Asian origin) and sooty mangabeys (African origin). Initial PCR analysis determined that the TCR deltaRec-PsiJalpha rearrangement leading to sjTREC formation occurs in both species. Primers to a DNA sequence conserved in macaques, mangabeys and humans were used in a quantitative competitive PCR assay to quantify sjTREC. We found that as in humans, sjTREC in these two monkey species decline with age. sjTREC are first generated in thymocytes during the early stages of TCR rearrangement. Lymph node CD4(+) and CD8(+) T cells contain more sjTREC than peripheral blood T cell populations, suggesting that recent thymic emigrants home to the lymphoid tissues. The sjTREC level is significantly higher within the peripheral blood CD4(+) and CD8(+) T cells of mangabeys compared to macaques. Removal of the thymus in four macaques led to a profound decrease in peripheral blood sjTREC level by 1 year post-thymectomy, indicating the lack of a significant extra-thymic source of peripheral naive T cells in macaques. Our results indicate that production, trafficking, and proliferation of recent thymic emigrants in these two monkey species represents a useful animal model system for understanding human immunological disorders.

Effect of ABC transporters on HIV-1 infection: inhibition of virus production by the MDR1 transporter

The MDR1 multidrug transporter P-gp (P-glycoprotein) is an efflux pump that extrudes diverse hydrophobic drugs and peptides from cells. Since the entry of HIV-1 into cells involves an initial interaction of the viral gp41 hydrophobic peptide with the plasma membrane, a potential effect of P-gp on HIV-1 infectivity was explored. Virus production was greatly decreased when P-gp was overexpressed at the surface of a continuous CD4(+) human T-leukemic cell line (12D7) infected with HIV-1(NL4-3), a T-tropic molecular clone of HIV-1. P-gp overexpression did not significantly alter the surface expression or distribution of either the HIV-1 receptor CD4 or the coreceptor CXCR4. Reduction of HIV-1 infectivity in P-gp-expressing cells occurred both during the fusion of viral and plasma membranes and at subsequent step(s) in the HIV-1 life cycle.

Emergency coronary artery bypass graft surgery in abciximab-treated patients

BACKGROUND

Although the platelet antiaggregant abciximab is frequently used with percutaneous coronary interventions, results of emergency coronary artery bypass graft operations in patients recently treated with abciximab are poorly characterized.

METHODS

During a 29-month period, 12 patients required emergency coronary artery bypass grafting within 12 hours (mean, 1.9 hours) of abciximab therapy. Our full standard heparin dose regimen was used (mean heparin dose, 53,000 U per patient). Each patient received a single platelet transfusion dose after protamine administration, and further blood products were transfused as necessary. Clinical outcome and transfusion requirements were compared with predicted results based on risk-adjusted historical patients.

RESULTS

No patients died and none were returned to the operating room for coagulopathy-related bleeding. Per patient transfusion requirements were as follows: red blood cells, 3.6 units; apheresis platelets, 1.4 units; and fresh frozen plasma, 1.5 units. As compared with predicted values, there was no excessive incidence of mortality, stroke, or red blood cell transfusion requirements.

CONCLUSIONS

Emergency coronary artery bypass graft operations using full-dose heparin can be performed successfully in acutely ischemic abciximab-treated patients. Prophylactic transfusion of platelets after protamine administration appears to be useful.

Kinesins in the nervous system

Both the development and the maintenance of neurons require a great deal of active cytoplasmic transport. Much of this transport is driven by microtubule motor proteins. Membranous organelles and other macromolecular assemblies bind motor proteins that then use cycles of adenosine 5'-triphosphate hydrolysis to move these 'cargoes' along microtubules. Different sets of cargoes are transported to distinct locations in the cell. The resulting differential distribution of materials almost certainly plays an important part in generating polarized neuronal morphologies and in maintaining their vectorial signalling activities. A number of different microtubule motor proteins function in neurons; presumably they are specialized for accomplishing different transport tasks. Questions about specific motor functions and the functional relationships between different motors present a great challenge. The answers will provide a much deeper understanding of fundamental transport mechanisms, as well as how these mechanisms are used to generate and sustain cellular asymmetries.