Food insecurity screening practices in a pediatric gastroenterology population

Food insecurity is a rising concern for US households and leads to adverse child health outcomes. Pediatric gastroenterology providers are uniquely equipped to help guide families experiencing this challenge given their specialized training in nutritional support and dietary therapy for disease management. Hence, this study aimed to evaluate food insecurity screening practices from the perspectives of patient caregivers and healthcare providers in a tertiary pediatric gastroenterology practice. A survey was administered to 1279 caregivers and 121 providers. Of the 248 completed caregiver responses, 10%-15% reported being asked about food insecurity. Among the 36 healthcare provider responses, 53% expressed comfort in conducting food insecurity screening but only 14% routinely screened. The most cited barrier to screening was the lack of readily available patient resources. Further research is imperative to address these screening barriers and assess the impact of food insecurity screening and interventions on pediatric gastrointestinal health outcomes.

A mitochondrial surveillance mechanism activated by SRSF2 mutations in hematologic malignancies

Splicing factor mutations are common in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but how they alter cellular functions is unclear. We show that the pathogenic SRSF2P95H/+ mutation disrupts the splicing of mitochondrial mRNAs, impairs mitochondrial complex I function, and robustly increases mitophagy. We also identified a mitochondrial surveillance mechanism by which mitochondrial dysfunction modifies splicing of the mitophagy activator PINK1 to remove a poison intron, increasing the stability and abundance of PINK1 mRNA and protein. SRSF2P95H-induced mitochondrial dysfunction increased PINK1 expression through this mechanism, which is essential for survival of SRSF2P95H/+ cells. Inhibition of splicing with a glycogen synthase kinase 3 inhibitor promoted retention of the poison intron, impairing mitophagy and activating apoptosis in SRSF2P95H/+ cells. These data reveal a homeostatic mechanism for sensing mitochondrial stress through PINK1 splicing and identify increased mitophagy as a disease marker and a therapeutic vulnerability in SRSF2P95H mutant MDS and AML.

Bone health screening practices with dual-energy X-ray absorptiometry and prediction of abnormal results in pediatric inflammatory bowel disease

OBJECTIVES

Pediatric patients diagnosed with inflammatory bowel disease (IBD) are at risk of suboptimal peak bone mass attainment. This study aimed to understand rates of bone health screening adherence, describe factors associated with dual-energy X-ray absorptiometry (DXA) acquisition, and identify factors associated with abnormal DXA.

METHODS

We performed a retrospective cohort study of pediatric IBD patients over a 10-year time frame. We included IBD patients (2-20 years of age) enrolled in ImproveCareNow and excluded patients with primary metabolic bone disease. Time-to-event methods and multivariable logistic regression were employed to identify factors associated with DXA acquisition and abnormal DXA.

RESULTS

In 676 patients, 464 (68.63%) pediatric patients with IBD had a risk factor for low bone mineral density (BMD); 137 (29.53%) underwent an initial DXA scan. Quiescent disease was significantly associated with a reduced likelihood of DXA (hazard ratio [HR]: 0.48; 95% confidence interval [CI]: 0.24-0.97), while weight z-score <-2 was significantly associated with DXA performance (HR: 2.07; 95% CI: 1.08-3.98). Abnormal DXA results (BMD z-score ≤-1) occurred in 59 (35.54%) individuals. After adjusting for visit diagnosis, delayed puberty, severe disease course, 6 months or greater of steroid exposure, and history of fracture, BMI z-score <-1 (odds ratio: 5.45; 95% CI: 2.41-12.33) was associated with abnormal DXA.

CONCLUSIONS

DXA screening occurred in less than one-third of eligible pediatric IBD patients. Compliance was more common in patients with a weight z-score <-2 and less common in those with quiescent disease. BMI strongly predicted abnormal DXA results when adjusting for risk factors for abnormal BMD.

Summer Olympic sports and female athletes: comparison of anti-doping collections and prohibited substances detected in Australia and New Zealand vs. France

Like any athlete, female athletes may be tempted to use prohibited substances during competition or training to enhance their performance. Anti-doping tests performed on female athletes in summer Olympic sports from two geographical areas: Australia/ New Zealand, and France were compared. First, the distribution of sample collections across different sports disciplines, as well as the distribution of substances was investigated. Then the distribution of collections and substances detected in the five sports categories (Strength/Speed, Endurance, Mixed, Motor Skills with High Energy Expenditure, and Motor Skills with Low Energy Expenditure) were studied with consideration of therapeutic use exemptions obtained by the athlete. Australia/New Zealand and France were similar in their overall number of anti-doping collections performed. Likewise, both regions had the same sports disciplines (athletics, aquatics, cycling) and sport categories (Mixed and Endurance) as having the highest number of sample collections. The Motor Skills with High Energy Expenditure, and Motor Skills with Low Energy Expenditure categories had the lowest number of sample collections. However, the number of substances detected was significantly different (p < 0.05) with a greater number of substances found in the French data. There were a few substances in common between the two geographical areas, namely prednisone/prednisolone, carboxy-THC, terbutaline, vilanterol and methylphenidate, but most were different. In-competition tests were the category where most of the AAFs were found.

Nicotinamide Riboside alleviates exercise intolerance in ANT1-deficient mice

Objective

Methods

Results

Conclusion

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ANT1-deficient mice demonstrate a reduced exercise capacity.

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ANT1-deficiency reduces complex I - linked respiration and the NAD/NADH redox state.

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Lack of NAD+ in skeletal muscle exacerbates exercise intolerance in ANT1 mice.

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Nicotinamide Riboside increases NAD+ and improves exercise capacity in ANT1 mice.

Synthesis, Crystal Structure, and Optical Characterization of the Sulfide Chloride Oxide CsBa6V4S12ClO4 with a Near-Infrared Fluorescence

When CsCl, BaS, BaO, V, and S are reacted in a solid-state reaction under inert conditions, pure powders and single crystals of senary CsBa₆V₄S₁₂ClO₄ can be obtained. Its unique crystal structure has the symmetry R3̅H (no. 148) and unit cell parameters a = 9.0575(2) and c = 28.339(1) Å. The crystal structure contains polar units [VS₃O]^3- and a complex BaS₇ClO₂ coordination. The compound gets its deep-red color from a low-energy charge transfer, which can be explained by an electron transfer from S^2- to V⁵⁺. In the near-infrared range, down-converted fluorescence occurs at 1.06 and 0.90 eV, and both emissions appear <450 ps after excitation at about 1.27 eV.

Bichalcogenide Model Systems for Magnetic Chains with Variable Spin Sizes and Optional Crystallographic Inversion Symmetry

To develop an understanding of the magnetism on one-dimensional lattices, one of the great challenges is to identify novel model systems with enough chemical flexibility to design the magnetic interactions in measurable samples. To contribute to this endeavor, we present a number of bichalcogenides with similar trigonal packing of magnetic chains. These chains consist of 3d transition-metal (TM) ions that are 6-fold-coordinated by S or Se. Each TM coordination can be described as a trigonally distorted octahedron that shares faces with two neighboring octahedra. A unique ability with these model systems is that an entity with electric polarity can be introduced between the chains that causes the TM ions in the chains to shift to polar positions, thereby allowing for magnetoelectric coupling. By a comparison of the macroscopic data of polar and nonpolar chains with either S = 1 or S = ³/₂, it is obvious that the magnetic properties are affected by the indirect electric polarity from the entity between the chains.

Spin-Orbit Coupling Controlled J=3/2 Electronic Ground State in 5d^{3} Oxides

Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca_{3}LiOsO_{6} and Ba_{2}YOsO_{6}, which reveals a dramatic spitting of the t_{2g} manifold. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal that the ground state of 5d^{3}-based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J=3/2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.

Spin-orbit coupling control of anisotropy, ground state and frustration in 5d(2) Sr2MgOsO6

The influence of spin-orbit coupling (SOC) on the physical properties of the 5d² system Sr₂MgOsO₆ is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr₂MgOsO₆ orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d² system of 0.60(2) μ_B–a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropy is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the size of the local moment in this compound. Through comparison to Sr₂ScOsO₆, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d² systems relative to their 5d³ counterparts, providing an explanation of the high T_N found in Sr₂MgOsO₆.

Epitaxial growth of iridate pyrochlore Nd2Ir2O7 films

Epitaxial films of the pyrochlore Nd₂Ir₂O₇ have been grown on (111)-oriented yttria-stabilized zirconia (YSZ) substrates by off-axis sputtering followed by post-growth annealing. X-ray diffraction (XRD) results demonstrate phase-pure epitaxial growth of the pyrochlore films on YSZ. Scanning transmission electron microscopy (STEM) investigation of an Nd₂Ir₂O₇ film with a short post-annealing provides insight into the mechanism for crystallization of Nd₂Ir₂O₇ during the post-annealing process. STEM images reveal clear pyrochlore ordering of Nd and Ir in the films. The epitaxial relationship between the YSZ and Nd₂Ir₂O₇ is observed clearly while some interfacial regions show a thin region with polycrystalline Ir nanocrystals.

A Novel Mental Health Crisis Service - Outcomes of Inpatient Data

INTRODUCTION

Northern Ireland has high mental health needs and a rising suicide rate. Our area has suffered a 32% reduction of inpatient beds consistent with the national drive towards community based treatment. Taking these factors into account, a new Mental Health Crisis Service was developed incorporating a high fidelity Crisis Response Home Treatment Team (CRHTT), Acute Day Care facility and two inpatient wards. The aim was to provide alternatives to inpatient admission. The new service would facilitate transition between inpatient and community care while decreasing bed occupancy and increasing treatment in the community.

METHODS

All services and processes were reviewed to assess deficiencies in current care. There was extensive consultation with internal and external stakeholders and process mapping using the COBRAs framework as a basis for the service improvement model. The project team set the service criteria and reviewed progress.

RESULTS

In the original service model, the average inpatient occupancy rate was 106.6%, admission rate was 48 patients per month and total length of stay was 23.4 days. After introducing the inpatient consultant hospital model, the average occupancy rate decreased to 90%, admissions to 43 per month and total length of stay to 22 days. The results further decreased to 83% occupancy, 32 admissions per month and total length of stay 12 days after CRHTT initiation.

DISCUSSION

The Crisis Service is still being evaluated but currently the model has provided safe alternatives to inpatient care. Involvement with patients, carers and all multidisciplinary teams is maximised to improve the quality and safety of care. Innovative ideas including structured weekly timetable and regular interface meetings have improved communication and allowed additional time for patient care.

Competing Superexchange Interactions in Double Perovskite Osmates

Double perovskites, A2BB'O6, containing mixed transition metal ions have exhibited numerous desirable properties such as colossal magnetoresistance, half metallic transport, and high temperature ferrimagnetism. However, a predictive understanding of the superexchange mechanisms which control the magnetism of these materials when they are insulating and B is 3d transition metal and B' is a 4d or 5d transition metal has remained elusive. In this work, a number of insulating double perovskite osmates, A2BOsO6 (A=Sr,Ca,La; B=Cr,Fe,Co,Ni) have been chosen and studied using magnetometry, specific heat, XMCD, and neutron powder diffraction techniques in order to systematically probe the effects of electronic configuration and bonding geometry on the magnetic ground state. It is concluded that the magnetic properties of these materials are controlled by a competition between short range B–O–Os and long range superexchange interactions which are sensitive to bonding geometry resulting in tunability of the magnetic ground state.

The time-dependent development of electric double-layers in pure water at metal electrodes: the effect of an applied voltage on the local pH

Water maintains a pH value of 7 owing to a balance between dissociation into hydronium (H 3 O + ) and hydroxide (OH − ) ions and their recombination. An examination is made of the effect of applying voltages from 0.1 to 0.82 V on these ions between metal electrodes which act as blocking electrodes. The movement of hydronium ions away from and hydroxide ions towards the anode is followed. This movement results in the formation of an ion double-layer with a steeply rising electric field and a maximum pH of approximately 12. At the cathode, the opposite occurs and the pH reaches a minimum of approximately 1.7. The time constant for double-layer formation is found to increase exponentially with voltage, and the pH at each electrode varies linearly with voltage; thus, the pH can be controlled systematically at each electrode. The dimensions of the double-layers are such that large biomolecules at the electrodes will be immersed in a pH environment close to the extreme values at the electrode. This means that the charge on the molecules may be controlled as they adsorb onto the electrode; this may prove valuable for the operation of biosensors.

Acyclovir and transmission of HIV-1 from persons infected with HIV-1 and HSV-2

BACKGROUND

Most persons who are infected with human immunodeficiency virus type 1 (HIV-1) are also infected with herpes simplex virus type 2 (HSV-2), which is frequently reactivated and is associated with increased plasma and genital levels of HIV-1. Therapy to suppress HSV-2 reduces the frequency of reactivation of HSV-2 as well as HIV-1 levels, suggesting that suppression of HSV-2 may reduce the risk of transmission of HIV-1.

METHODS

We conducted a randomized, placebo-controlled trial of suppressive therapy for HSV-2 (acyclovir at a dose of 400 mg orally twice daily) in couples in which only one of the partners was seropositive for HIV-1 (CD4 count, > or = 250 cells per cubic millimeter) and that partner was also infected with HSV-2 and was not taking antiretroviral therapy at the time of enrollment. The primary end point was transmission of HIV-1 to the partner who was not initially infected with HIV-1; linkage of transmissions was assessed by means of genetic sequencing of viruses.

RESULTS

A total of 3408 couples were enrolled at 14 sites in Africa. Of the partners who were infected with HIV-1, 68% were women, and the baseline median CD4 count was 462 cells per cubic millimeter. Of 132 HIV-1 seroconversions that occurred after randomization (an incidence of 2.7 per 100 person-years), 84 were linked within couples by viral sequencing: 41 in the acyclovir group and 43 in the placebo group (hazard ratio with acyclovir, 0.92, 95% confidence interval [CI], 0.60 to 1.41; P=0.69). Suppression with acyclovir reduced the mean plasma concentration of HIV-1 by 0.25 log(10) copies per milliliter (95% CI, 0.22 to 0.29; P<0.001) and the occurrence of HSV-2-positive genital ulcers by 73% (risk ratio, 0.27; 95% CI, 0.20 to 0.36; P<0.001). A total of 92% of the partners infected with HIV-1 and 84% of the partners not infected with HIV-1 remained in the study for 24 months. The level of adherence to the dispensed study drug was 96%. No serious adverse events related to acyclovir were observed.

CONCLUSIONS

Daily acyclovir therapy did not reduce the risk of transmission of HIV-1, despite a reduction in plasma HIV-1 RNA of 0.25 log(10) copies per milliliter and a 73% reduction in the occurrence of genital ulcers due to HSV-2. (ClinicalTrials.gov number, NCT00194519.)

Bimodal effect of humic acids on the LPS-induced TNF-alpha release from differentiated U937 cells

Humic substances (HS) have been reported to possess anti-inflammatory as well as pro-inflammatory properties. The anti-inflammatory activity was demonstrated in the rat paw edema model and we found a preliminary explanation in the 5-lipoxygenase inhibitory effect of humic acids (HA). The pro-inflammatory activity is reflected by the production and release of pro-inflammatory cytokines in HA-treated neutrophilic granulocytes. With regard to the potential use of HA as antiviral and UV-protective agents it appears advisable to investigate the role of HS in the inflammation process in more detail. Hence we tested four different HS preparations - two naturally occurring HA from the Altteich peatland in Germany, one fulvic acid (FA) preparation from a Finnish spruce forest and a synthetic HA-like polymer (caffeic acid oxidation product, KOP) for their influence on the lipopolysaccharide (LPS)-induced TNF-alpha release in human U937 cells. In addition, the cytotoxicity of HS was determined. The results demonstrate a concentration-dependent bimodal effect of HA on the TNF-alpha release of differentiated LPS-stimulated U937 cells for both the natural black peat HA from the Altteich peatland and the HA-like polymer KOP. Low HA concentrations (10-80 microg/ml) enhanced the TNF-alpha release by up to threefold (pro-inflammatory activity), while HA concentrations >100 microg/ml reduced it about 10-fold (anti-inflammatory activity). FA failed to enhance TNF-alpha release, but reduced it at higher concentrations (>200 microg/ml) by the half. Brown water HA did not exert any significant effect on TNF-alpha release. No HS-stimulated TNF-alpha release was also observed in the absence of exogenously supplied LPS. This means that HS, unlike endotoxin, are no inflammation-causing agents for LPS-untreated cells. Differences in the effect of individual HS on TNF-alpha release are discussed in connection with the polyanionic character of HS, their molecular mass distribution and the hitherto imperfectly known chemical structure.

Neuromedin U can exert colon-specific, enteric nerve-mediated prokinetic activity, via a pathway involving NMU1 receptor activation

BACKGROUND AND PURPOSE

The neuromedin U (NMU) receptors, NMU1 and NMU2, are expressed in the gut but their functions are unclear. This study explores the role of NMU in gastrointestinal motility.

EXPERIMENTAL APPROACH

The effects of NMU were examined in the forestomach and colon isolated from NMU2R wild-type and NMU2R-/- (knockout) mice, looking for changes in muscle tension and in nerve-mediated responses evoked by electrical field stimulation (EFS), and in models of peristalsis in mouse colon and faecal pellet transit in guinea-pig colon.

KEY RESULTS

In the mouse forestomach, NMU (1 nM-10 microM) concentration-dependently induced muscle contraction, in the presence of tetrodotoxin and atropine, in preparations from both wild-type and NMU2R-/- mice (pEC50: 7.9, 7.6, Emax: 0.26, 0.20g tension, respectively, n=8 each concentration). The same concentrations of NMU had no consistent effects on the responses to EFS (n=8). In the mouse colon, NMU (0.1 nM-1 microM) had no significant effect on baseline muscle tension (n=8), but concentration-dependently potentiated EFS-evoked contractions in preparations from both wild-type and NMU2R-/- mice, pEC50: 8.1, 7.8, Emax: 24%, 21%, respectively, n=6-11. NMU (0.01 nM-0.1 microM, n=5-7) concentration-dependently decreased the interval between waves of peristalsis in the mouse colon (pEC50: 8.8) and increased the rate at which a faecal pellet moved along the guinea-pig colon.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that NMU exerts colon-specific, nerve-mediated, prokinetic activity, via a pathway involving activation of NMU1 receptors. This suggests that this receptor may represent a molecular target for the treatment of intestinal motility disorders.

Performance of a novel test for IgM and IgG antibodies in subjects with culture-documented genital herpes simplex virus-1 or -2 -infection

Novel tests (BioPlex) for herpes simplex virus-1 (HSV-1) and HSV-2 IgG were compared with HerpeSelect HSV-1 and HSV-2 ELISAs for type-specific IgG. The sensitivity and specificity of BioPlex HSV-1 IgG were 94% (84/89) and 96% (119/124), respectively, with unselected sera, while the sensitivity and specificity of BioPlex HSV-2 IgG were 92% (109/118) and 98% (95/97), respectively. BioPlex IgM was compared with Diamedix IgM against sera from patients with culture-documented genital herpes. The test results were concordant in 81% of sera from HSV-1 patients and in 90% of sera from HSV-2 patients. Use of BioPlex IgM in addition to BioPlex IgG tests increased HSV-2 seroconversion detection from 47% of subjects to 70%. Use of Diamedix IgM in addition to Focus IgG ELISA increased HSV-2 detection from 40% of subjects to 70%. IgM was detected by BioPlex in 63% of sera from patients with early HSV-2 infection (< 30 days) and in 59% of sera by Diamedix. IgM was also detected in a large proportion of sera from subjects with established HSV-2 infection (33% by BioPlex and 29% by Diamedix). Addition of IgM testing substantially increased the ability to detect seroconversion early in infection. IgM is an indicator of recent infection only in subjects who lack detectable IgG.

Baculovirus expression and antigenic characterization of the capsid proteins of three Norwalk-like viruses

Human caliciviruses (HuCVs) are antigenically diverse. The antigenic relationships among different HuCVs have been difficult to study because HuCVs cannot be passaged in the laboratory. In this study, we describe cloning, sequencing and expression of the viral capsid proteins of three HuCVs that were identified in outbreaks of acute gastroenteritis in Virginia in 1997-1998. Yields of the capsid proteins similar to previously expressed recombinant Norwalk virus were obtained using the baculovirus expression system. Recombinant VA97207 capsid protein (rVA97207) and rVA98387, but not rVA98115, formed virus-like particles (VLPs). All three recombinant capsid antigens detected seroresponses in patients involved in outbreaks of acute gastroenteritis associated with genetically homologous or related HuCVs. The antigenic relationships of the three strains were further characterized using hyperimmune antisera against the three capsid antigens as well as four previously characterized recombinant capsid antigens of Norwalk (rNV), Mexico (rMxV), Hawaii (rHV), and Grimsby viruses (rGrV). VA98387 shared 98% aa identity with GrV; rVA98387 was detected by antisera to GrV. VA98115 shared 87% aa identity with Desert Storm virus and 65% aa identity with prototype Norwalk virus (NV); rVA98115 reacted weakly with NV antisera. VA97207 shared 80% aa identity with Amsterdam and 75% aa identity with Leeds strains and rVA97207 was not detected by any of the heterologous antibodies. In conclusion, VA97207 and VA98115 may belong to CV antigenic types not previously expressed, while VA98387 is a GrV-like virus. Low levels of cross-reactive antibodies were detected between types. Further studies to characterize these antigens and to develop enzyme immune assays (EIAs) for these strains are in progress.

Cultural systems for growing potatoes in space

Higher plants are being evaluated for life support to provide needed food, oxygen and water as well as removal of carbon dioxide from the atmosphere. The successful utilization of plants in space will require the development of not only highly productive growing systems but also highly efficient bioregenerative systems. It will be necessary to recycle all inedible plant parts and all human wastes so that the entire complement of elemental compounds can be reused. Potatoes have been proposed as one of the desirable crops because they are 1) extremely productive, yielding more than 100 metric tons per hectare from field plantings, 2) the edible tubers are high in digestible starch (70%) and protein (10%) on a dry weight basis, 3) up to 80% of the total plant production is in tubers and thus edible, 4) the plants are easily propagated either from tubers or from tissue culture plantlets, 5) the tubers can be utilized with a minimum of processing, and 6) potatoes can be prepared in a variety of different forms for the human diet (Tibbitts et al., 1982). However potatoes have a growth pattern that complicates the development of growing the plants in controlled systems. Tubers are borne on underground stems that are botanically termed 'rhizomes', but in common usage termed 'stolons'. The stolons must be maintained in a dark, moist area with sufficient provision for enlargement of tubers. Stems rapidly terminate in flowers forcing extensive branching and spreading of plants so that individual plants will cover 0.2 m2 or more area. Thus the growing system must be developed to provide an area that is darkened for tuber and root growth and of sufficient size for plant spread. A system developed for growing potatoes, or any plants, in space will have certain requirements that must be met to make them a useful part of a life support system. The system must 1) be constructed of materials, and involve media, that can be reused for many successive cycles of plant growth, 2) involve a minimum quantity of media, 3) contain media that is essentially inert and not oxidize or degrade with use, 4) utilize a recirculating nutrient solution to permit regulation of pH and nutrient concentrations, and 5) be capable of complete automation of all planting, maintenance and harvesting procedures.

Vagal nerve stimulation: adjustments to reduce painful side effects

Vagal nerve stimulation is an approved adjunctive treatment for medically intractable epilepsy. Although it is generally well tolerated, some patients experience pain, coughing, or hoarseness during stimulation. Lowering the pulse width in these patients alleviates pain and reduces voice alteration without loss of efficacy. This allows more optimal programming of stimulation intensities.

Characterisation of gene expression changes following permanent MCAO in the rat using subtractive hybridisation

Failure of several putative neuroprotectants in large multicentred clinical trials has re-focussed attention on the predictability of pre-clinical animal models of stroke. Model characterisation and relationship to heterogeneous patient sub-groups remains of paramount importance. Information gained from magnetic resonance imaging (MRI) signatures indicates that the Zea Longa model of rat middle cerebral artery occlusion may be more representative of slowly evolving infarcts. Understanding the molecular changes over several hours following cerebral ischaemia will allow detailed characterisation of the adaptive response to brain injury. Using a fully characterised model of Zea Longa middle cerebral artery occlusion we have used the representational difference analysis (RDA) subtractive hybridisation method to identify transcripts that accumulate in the ischaemic cortex. Along with a number of established ischaemia-induced gene products (including MCP-1, TIMP-1, hsp 70) we were also able to identify nine genes which have not previously been shown to accumulate following focal ischaemia (including SOCS-3, GADD45gamma, Xin).

Quantification of urinary excretion of ethosuximide enantiomers and their major metabolites in the rat

A chiral gas chromatographic assay has been developed for quantitative analysis of ethosuximide and its major metabolites in rat urine. The extraction procedure was found to be precise and reproducible. Recovery was in the range of 94-98%, intraday CV(%) was 0.92% for (S)-ethosuximide (50 microg/ml) and 0.51% for (R)-ethosuximide (50 microg/ml). Interday CV(%) was 1.12% for (S)-ethosuximide and 0.72% for (R)-ethosuximide. The limit of detection was determined to be around 0.01 microg/ml for each enantiomer. Following administration of rac-ethosuximide by i.v., i.p. and oral routes, unchanged ethosuximide was detected in urine up to 72 h after drug administration. The appearance of all detected metabolites occurred within 24 h of drug administration. Significantly more (S)-ethosuximide was excreted unchanged than (R)-ethosuximide with all three routes studied. A substantial amount of the drug was eliminated as the 2-(1-hydroxyethyl)-2-methylsuccinimide (2 pairs of diastereoisomers). Much less drug was eliminated as the 2-ethyl-3-hydroxy-2-methylsuccinimide with only one diastereoisomer observed. Examination of the one pair of diastereoisomers of 2-(1-hydroxyethyl)-2-methylsuccinimide that was resolved showed preferential excretion of one isomer. Comparison of both pairs of diastereoisomers showed that one pair was formed in preference to the other with a ratio of approximately 0.8:1. It is concluded that stereoselective metabolism of ethosuximide occurs.

Heart transplantation in children: indications. Report of the Ad Hoc Subcommittee of the Pediatric Committee of the American Society of Transplantation (AST)

This review details the indications for heart transplantation in children. Contraindications have evolved from absolute to relative. Controversial issues remain and this paper represents a consensus of more than a dozen centers that have programs that remain active performing pediatric heart transplants.

The Morehouse Faculty Development Program: methods and 3-year outcomes

BACKGROUND AND OBJECTIVES

Faculty development is an established method for increasing the number and effectiveness of faculty in family medicine. However, few published studies focus specifically on the use of faculty development to increase minority representation among faculty. Underrepresented minorities comprise 20% of the nation's population but only 3% of medical school faculty. In the entire nation, only 52 full-time teachers of family medicine are African-Americans. Morehouse School of Medicine has developed an effective model for training large numbers of underrepresented minority physicians to become academic family physicians. From 1993-1996, we trained 23 community-based physicians, three new faculty, six existing faculty, and three full-time fellows as teachers of family medicine. Of 35 participants, 33 were underrepresented minorities. Cultural issues in teaching and communication are an integral part of the curriculum. Seventy-three percent of graduates now teach medical students or residents either full-time or part-time. Further studies are needed to test the replicability of this model in non-minority institutions, as well as to achieve greater cost-effectiveness and improve academic outcomes such as publications and research. Significant faculty diversity is necessary and achievable, if institutions are willing to commit significant resources and network with minority health professionals and institutions.

Essential obstetric care: assessment and determinants of quality

This paper reports on a study to develop and to apply methods for measuring the quality of essential obstetric care (EOC) in health centers. Based on a Nigerian guideline and an international guideline, and in consultation with local experts in primary care obstetrics, norms were established for equipment, personnel, supplies and the process of EOC, focusing on critical tasks. A combination of assessment methods was used, including observation of tasks performed during intrapartum care; use of data from records of care kept by midwives during the period of observation; use of data from records kept by midwives in the calendar year preceding the period of observation; exit interviews with clients; and inventories of equipment and supplies. Twelve health centers in three Local Government Areas (LGAs) and 360 clients in labor were included in the study. Quality of care was measured quantitatively as a score, calculated for each task and for each delivery in the health center. The results show that the methods developed are useful for: identifying quality score differences among health centers, and the effects of methods of assessment on quality scores; identifying aspects of EOC requiring improvements within each health center; and identifying factors influencing the quality of care, as a basis for effective quality improvement efforts. Regression models show that the most consistent and important predictor of quality scores is the use of printed forms (i.e. routine records of labor) during intrapartum care. Printed forms served as job aids, providing prompts that reminded midwives to perform specific tasks.

Structural features of collapsin required for biological activity and distribution of binding sites in the developing chick

We have used Fc-chimeras of collapsin-1/Sema III to study the structure-function activity of this recently identified repulsive axonal guidance molecule and to map the distribution of its binding sites during chick development. Our results show that the biological activity of the collapsin-Fc in an in vitro collapse assay is independent of both the Ig-domain and the positive charged carboxy terminus. Collapsin binding sites were found on a number of neuronal fiber tracts, and in two instances (DRG tracts and the retinotectal projection) this expression is both highly dynamic and consistent with them playing a role in axonal growth and guidance. Collapsin-1 binding sites were also found on a number of nonneuronal structures that do not produce collapsin-1 mRNA. We postulate that these sites may act to localize or concentrate collapsin-1 released from growing axons and in this way allow for an autocrine axonal guidance mechanism to function during development.

Fetal urine production rates following intrauterine transfusion

This study investigates the hypothesis that following an intrauterine, intravascular transfusion (IVT), one of the physiologic adaptations might be an increase in the fetal urine production. The hourly fetal urine production rate (HFUPR) was measured for the first hour following 12 transfusions and for 24 h following 5 transfusions in anemic isoimmunized fetuses. The HFUPR was also measured in 5 control fetuses who underwent fetal blood sampling without transfusion. Fetal hemoglobin, hematocrit and blood viscosity were measured before and after each transfusion. The HFUPR fell significantly from a mean (SEM) of 19.2 (2.85) to 7.4 (2.2) ml/h, and remained low for at least 4 h posttransfusion returning to pretransfusion rates by 24 h. There was no change in the HFUPR in the control fetuses. The study suggests that in human fetuses the rapid excretion of excess fluid via the renal tract is not an acute adaptive response to an IVT.

Survival and risk factors for death after cardiac transplantation in infants. A multi-institutional study. The Pediatric Heart Transplant Study

BACKGROUND

Despite the increasing application of cardiac transplantation in infants, reported survival rates vary, and risk factors for death are poorly understood.

METHODS AND RESULTS

To examine early survival and risk factors for death in infants (< 1 year of age) undergoing cardiac transplantation, 141 infants (36 < 1 months of age) underwent primary cardiac transplantation between January 1, 1993, and January 1, 1995, at 23 centers in the Pediatric Heart Transplant Study (PHTS). Diagnoses were hypoplastic left heart syndrome (66%), other congenital heart disease (17%), cardiomyopathy (14%), and other (3%). Actuarial survival after cardiac transplantation was 84% at 1 month, 70% at 1 year, and 69% at 2 years, with the greatest hazard for death within the first 3 months. The principal cause of death was early graft failure in 20 patients (52% of deaths), infection in 10 (26% of deaths), and rejection in 4 (10%). On the basis of multivariate analysis, risk factors for early mortality were history of previous sternotomy (P = .0003), nonidentical blood type donor (P = .01), recipient non-blood group A (P = .02), and donor cause of death other than closed head trauma (P = .04). Diagnosis at listing, waiting time (mean, 1.3 months), graft ischemic time (mean, 228 minutes; range, 68 to 479 minutes), and recipient ventilatory or inotropic support at listing were not predictive for mortality after transplant.

CONCLUSIONS

The higher mortality rate observed with infant heart transplantation is due to a higher mortality within the first month after transplantation as a result of early graft failure. Strategies to improve donor heart function at implantation would have the greatest impact on survival after infant cardiac transplantation.

Tuberculosis screening and anergy in a homeless population

BACKGROUND

Tuberculosis has again emerged as a growing public health concern in the United States. Among the homeless population, increased risk factors contribute to immunodeficiency, which can cause false-negative results on purified protein derivative (tuberculin) (PPD) skin testing, the standard screening procedure for tuberculosis in individuals. We evaluated the accuracy of PPD skin test results by determining anergy status of patients when offering the PPD test.

METHODS

A consecutive convenience sample of 105 underserved men and women were tested at a health clinic located in a homeless shelter in Yonkers, NY. These persons were currently homeless, living in a shelter, or formerly homeless and using the soup kitchen at the shelter. Three antigens, candidin, mumps, and trichophytin, in addition to PPD, were administered intradermally using the Mantoux method, and results were read 48 to 72 hours later on the 100 (95 percent) who returned. An individual was considered to be anergic if the delayed-type hypersensitivity reactions were less than or equal to 2 mm for each of the four antigens.

RESULTS

Of the 100 persons who returned for follow-up, 5 (5 percent) were found to be anergic. Of these 5, all were previously known to be positive for human immunodeficiency virus (HIV).

CONCLUSIONS

PPD testing alone was found to be an accurate screening test in this population except in those who were HIV positive.

Introducing quality management into primary health care services in Uganda

In 1994, a national quality assurance programme was established in Uganda to strengthen district-level management of primary health care services. Within 18 months both objective and subjective improvements in the quality of services had been observed. In the examples documented here, there was a major reduction in maternal mortality among pregnant women referred to Jinja District Hospital, a reduction in waiting times and increased patient satisfaction at Masaka District Hospital, and a marked reduction in reported cases of measles in Arua District. Beyond these quantitative improvements, increased morale of district health team members, improved satisfaction among patients, and greater involvement of local government in the decisions of district health committees have been observed. At the central level, the increased coordination of activities has led to new guidelines for financial management and the procurement of supplies. District quality management workshops followed up by regular support visits from the Ministry of Health headquarters have led to a greater understanding by central staff of the issues faced at the district level. The quality assurance programme has also fostered improved coordination among national disease-control programmes. Difficulties encountered at the central level have included delays in carrying out district support visits and the failure to provide appropriate support. At the district level, some health teams tackled problems over which they had little control or which were overly complex; others lacked the management capacity for problem solving.

Concepts and methods for assessing the quality of essential obstetric care

Approaches to reducing maternal mortality and morbidity have attracted much attention in the last decade. It is recognized that availability and use of essential obstetric care (EOC) of sound quality by women in labor would reduce the burden of illness and death resulting from pregnancy. However, the literature on methods for defining, assessing and improving the quality of EOC at the point of service delivery in developing countries is quite weak. Drawing upon fundamental concepts of quality assurance, statistics, clinical practices and health service management, this article presents unifying concepts and methods for defining, assessing and improving the quality of EOC in developing country settings. It argues that any intervention that would improve the quality of EOC must act through at least one of three mechanisms: improve the clinical management of uncomplicated labor; improve the detection of complications of labor; or, improve the clinical management of complications of labor. The text presents the basis for using quantitative and qualitative methods to assess the quality of EOC. It concludes that any method to assess the quality of EOC, as a basis for improvement at the health center level, must satisfy the following seven criteria: (i) be derived from scientifically sound and locally defined guidelines for what constitutes care of good quality; (ii) enable objectively verifiable measurements of the performance of critical tasks; (iii) be sufficiently discriminating to detect variations in quality among health centers, thereby enabling managers to focus on improving care in those health centers providing care of lower quality; (iv) facilitate production of visual aids within each health center, thereby enabling midwives, doctors and their supervisors to use information for improving their work on a daily basis; (v) include qualitative assessments to facilitate interpretation of quantitative information; (vi) be reasonably simple to use without unsustainable foreign technical assistance; and, (vii) be affordable within the limited resources of public health facilities and District Health Management Teams.

The prognostic factors in the prenatal diagnosis of the echogenic fetal lung

The prenatal diagnosis of an echogenic fetal lung (EFL) is now often made in the early second trimester using high-resolution ultrasound. This ultrasound appearance is usually caused by a congenital cystic adenomatoid lung malformation (CCAM), an intrapulmonary lung sequestration or obstruction of a major airway. In order to provide prognostic guidelines to parents who may be considering termination of a fetus with these findings, we have analysed a series of 11 cases diagnosed in our centre over the past 2 years in conjunction with 60 cases from major published series. The data suggest that in the absence of non-immune hydrops fetalis (NIHF) or other anomalies, the outcome for the fetuses is excellent, with over 90 per cent survival. Neither early diagnosis (24 weeks) nor the presence of mediastinal shift is a poor prognostic indicator. In addition, it appears that if NIHF is absent at diagnosis, the chance that it will develop as the pregnancy continues is small (6 per cent). Furthermore, there is a significant (up to 30 per cent) chance that this ultrasound finding will resolve in utero. The development of in utero fetal surgical techniques may be the only hope for those hydropic fetuses who appear to have a dismal prognosis.

Value of faecal alpha-1-antitrypsin, haemoglobin and a chemical occult blood test in the detection of gastrointestinal disease

Specimens from hospital out-patients and in-patients sent for faecal occult blood tests were also analysed for faecal alpha-1-antitrypsin and faecal haemoglobin. 453 stool specimens from 222 patients were analysed. The clinicians were only aware of the faecal occult blood test results, and diagnoses were made using conventional clinical and investigative criteria. Gastrointestinal bleeding or putative sites of bleeding were diagnosed in 98 patients, whereas in 81 patients putative sites of bleeding were not found or other cause of anaemia diagnosed. In 41 patients there was insufficient information to reach a definitive diagnosis. Comparison of the 3 faecal tests using these grouping methods showed that faecal alpha-1-antitrypsin performed best, with an accuracy of 89%, specificity of 90% and sensitivity of 88%, all significantly better (P < 0.001) than the faecal occult blood test (68%, 60% and 73%, respectively). There was no significant difference between the performance of the faecal occult blood and faecal haemoglobin tests. Faecal alpha-1-antitrypsin measurement may be a useful investigation in situations where a faecal occult blood test would normally be requested.