Promising Fluorine-Free Ion Exchange Membranes Based on a Poly(ether-block-amide) Copolymer and Sulfonated Montmorillonite: Influence of Different Copolymer Segment Ratios

Novel composite membranes employing a poly(ether-block-amide) (PEBAX) copolymer and sulfonated montmorillonite (S-MMT) as a filler were developed. The ratio of polyether to polyamide blocks was investigated using PEBAX 2533 and PEBAX 4533 based on the membrane properties and performance. Additionally, the effect of the changing filler ratio was monitored. The interaction between the S-MMT as nanofiller and the polymer matrix of PEBAX2533 and PEBAX4533 as well as the crystalline nature and thermal and mechanical stability of the composite membranes were evaluated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and tensile test. The composite membrane with 7 wt.% S-MMT showed the highest water uptake of 21% and 16% and an acceptable swelling degree of 16% and 9% for PEBAX 2533 and PEBAX 4533 composite membranes, respectively. In terms of water uptake and ion exchange capacity at room temperature, the new un-protonated membranes are superior to un-protonated Nafion. Meanwhile, with the same S-MMT content, the ion conductivity of PEBAX 2533 and PEBAX 4533 composite membranes is 2 and 1.6 mS/cm, and their ion exchange capacity is 0.9 and 1.10 meq/g.

Development of WO3-Nafion Based Membranes for Enabling Higher Water Retention at Low Humidity and Enhancing PEMFC Performance at Intermediate Temperature Operation

The proton exchange membrane (PEM) represents a pivotal material and a key challenge in developing fuel cell science and hydrogen technology. Nafion is the most promising polymer which will lead to its commercialisation. Hybrid membranes of nanosized tungsten oxide (WO₃) and Nafion were fabricated, characterised, and tested in a single cell. The incorporation of 10 wt% WO₃ resulted in 21% higher water uptake, 11.7% lower swelling ratio, almost doubling the hydration degree, and 13% higher mechanical stability of the hybrid membrane compared to the Nafion XL. Compared to commercial Nafion XL, the rNF-WO-10 hybrid membrane showed an 8.8% and 20% increase in current density of the cell at 0.4 V operating at 80 and 95 °C with 1.89 and 2.29 A/cm², respectively. The maximum power density has increased by 9% (0.76 W/cm²) and 19.9% (0.922 W/cm²) when operating at the same temperatures compared to the commercial Nafion XL membrane. Generally, considering the particular structure of Nafion XL, our Nafion-based membrane with 10 wt% WO₃ (rNF-WO-10) is a suitable PEM with a comparable performance at different operating conditions.

Serological and molecular surveys of Anaplasma spp. in Egyptian cattle reveal high A. marginale infection prevalence

BACKGROUND

Bovine anaplasmosis is an infectious disease with worldwide distribution. It spreads by various routes mainly through tick bites.

AIMS

This study aimed to investigate bovine related Anaplasma spp. in cattle from three northern governorates of Egypt by serological and molecular assays, to evaluate the associated risk factors and to analyze the phylogeny of revealed A. marginale isolates.

METHODS

During 2020, a total of 650 blood samples were collected from asymptomatic cattle in the governorates of Kafr El-Sheikh (n=240), Menofia (n=230), and Al-Gharbia (n=180). Sera samples were examined using the Anaplasma antibody test kit, cELISA v2. Blood genomic DNA of seropositive cattle was then examined by PCRs specific to A. marginale, A. centrale, and A. bovis. Selected positive samples were subjected to nucleotide sequencing. Risk factors (i.e. geographical area, breed, type of production, sex, age, herd size, season, husbandry system, tick infestation, and application of acaricides) were evaluated by logistic regression approach.

RESULTS

In total, 130 cattle (20%, 95% CI: 17.1-23.3) were recorded seropositive for Anaplasma species. Major risk factors associated with seropositivity were being crossbred, dairy cattle, aged more than 5 years, summer season, herd size of below 300, pasture grazing, tick infestation, and not being subjected to regular treatment with acaricides. By using species-specific PCR, only A. marginale was detected. Nucleotide sequencing showed the occurrence of two different msp4 genotypes.

CONCLUSION

This study shows the high prevalence of A. marginale in cattle of Kafr El-Sheikh, Al-Gharbia, and Menofia. However, the connection between Anaplasma species and their tick vectors remains unknown in Egypt and merits further investigations. Since these infections primarily spread through ixodid tick bites, effective ectoparasite control strategies, regular examination of cattle and successful chemoprophylaxis are recommended.

Facile Preparation of a Laponite/PVA Mixed Matrix Membrane for Efficient and Sustainable Pervaporative Dehydration of C1-C3 Alcohols

The exfoliation method was applied for the preparation of high-water selective mixed matrix membranes (MMMs), especially for the dehydration of C1-C3 alcohol-water solutions. Herein, a facile and easy method was employed to fabricate physically cross-linked Laponite nanosilicate clay-PVA MMMs without additional cross-linking by a one-step synthesis route for water dehydration from methanol, ethanol, and isopropanol aqueous solutions. The morphologies, chemical structures, thermal stabilities, and surface hydrophilicity of Laponite-PVA MMMs were investigated properly by different characterization techniques. The Laponite concentration has affected the fractional free volume of the membranes, as proven by positron annihilation lifetime spectroscopy analysis. The MMMs displayed both a significant improvement in the separation factor and remarkable enhancement in the permeation fluxes for the three alcohol systems. The influence of the operating temperature on the MMM performance was investigated for the methanol/water solution. The methanol permeability was 100-fold lower than that of the water, indicating that the membranes are more water selective. Particularly, the Laponite-PVA membrane with 5 mg/mL Laponite loading exhibits excellent separation efficiency for C1-C3 dehydration having water permeabilities higher than most other polymeric membranes from the other literature studies of 2.82, 2.08, and 1.56 mg m^-1 h^-1 kPa^-1 for methanol, ethanol, and isopropanol/water systems, respectively. This membrane development allows a more efficient and sustainable separation of aqueous alcoholic mixtures.

Pervaporative Dehydration of Methanol Using PVA/Nanoclay Mixed Matrix Membranes: Experiments and Modeling

Encouraged by the industrial problem of removing water from methanol solutions, a simple exfoliation method is applied to prepare polyvinyl alcohol (PVA)/laponite nanoclay mixed matrix membranes (MMMs). The membranes are used for the pervaporative dehydration of the methanol-water solution. The influence of the nanoclay content on the pervaporation performance is investigated. The results show that the PVA10 membrane containing 10 wt% Laponite loading exhibits excellent separation efficiency; therefore, all the experimental work is continued using the same membrane. Additionally, the effects of feed concentration and temperature on methanol dehydration performance are thoroughly investigated. The temperatures are ranging from 40–70 °C and the water feed concentrations from 1–15 wt% water. A maximum separation factor of 1120 can be observed at 40 °C and the feed water concentration of 1 wt%. Remarkably, two solution–diffusion models, the Rautenbach (Model I) and modified method by Valentínyi et al. (Model II), are used and compared to evaluate and describe the pervaporation performance of the mixed matrix membrane. Model II proves to be more appropriate for the modeling of pervaporative dehydration of methanol than Model I. This work demonstrates that PVA/nanoclay mixed matrix membranes prepared can efficiently remove water from methanol aqueous solution with pervaporation and the whole process can be accurately modeled with Model II.

Impact of perioperative right ventricular assist device on ventricular arrhythmias in patients with continuous flow left ventricular assist device

Background

Patients with continuous flow left ventricular assist device (LVAD) may develop right ventricular failure in perioperative period of LVAD implantation. Some of these patients require temporary support with right ventricular assist device (RVAD). There is paucity of data regarding the impact of RVAD support on incidence of ventricular arrhythmias (VA) in LVAD patients.

Purpose

To assess the impact of perioperative RVAD support on the incidence of VA in the first 6 months after LVAD implant.

Methods

This is a retrospective study including 316 patients undergoing LVAD implantation at the University of Nebraska Medical Center, USA since 2012. Patients were divided into 2 groups- those who required perioperative RVAD support (BiVAD group) and those who did not require it (LVAD only group). VA was defined as any sustained ventricular tachyarrhythmia lasting more than 30 seconds or requiring therapy from implantable cardioverter-defibrillator. Incidence of VA in the first 6 months post-LVAD implantation was analyzed and compared between the groups using Cox proportional hazards regression analysis.

Results

Out of 316 total patients, 52 (16%) patients required RVAD support. The difference in age, gender, race and medications between the two groups was not statistically significant. The patients in BiVAD group had a higher incidence of post-LVAD VA (35%) as compared to LVAD only group (21%). On Cox proportional hazards regression analysis, the difference was found to be statistically significant even after adjusting for history of pre-LVAD VAs (HR: 2.27; p=0.02) (Figure 1).

Conclusion

In this large single center cohort of LVAD patients, we noticed a statistically higher incidence of VA in subgroup of patients requiring perioperative RVAD support.

Figure 1

Funding Acknowledgement

Type of funding source: None

Comparison of Single and Double-Network PVA Pervaporation Performance: Effect of Operating Temperature

Thermal crosslinking sequential method applied for DN-PVAs generation efficiently. The swelling measurements investigated that the hydrophilicity of the membrane decreases because of the collaboration of the second thermal crosslinked PVA matrix. The dehydration performance of ethanol solution showed improved using the thermal crosslinked double network PVA membrane. The pervaporation dehydration of the water-ethanol mixture was investigated at different conditions. The separation selectivity showed a significant improvement, while the permeation flux declines due to the incorporation of the second PVA network under 95 % ethanol and at 40 °C. Increasing the feed temperature enhanced the permeability of the membrane, while decreasing the water content in the feed resulted in an increase in the selectivity. The overall results showed that, at high operating temperature and high ethanol concentration in the feed, the prepared membranes are highly selective towards the water with reasonable fluxes values. The influence of temperature permeation parameter and diffusion coefficient of the feed component is also discussed. The negative heat of sorption ( ∆Hs ) values calculated on the basis of the estimated Arrhenius activation energy values indicates that the sorption process is controlled by Langmuir's mode.

Modelling of Hybrid Method for VOC Removal from Process Wastewater: Distillation and Hydrophilic Pervaporation

The study is motivated by the industrial problem from pharmaceutical industry, which is ethanol and methanol removal from process wastewater. To complete this goal hybrid method is investigated and optimized. Two distillation columns are sufficient for separation of alcohol-water mixture. Suitable water can be purified as bottom product of first column. Ethanol and methanol purification is achieved with combination of second distillation column and pervaporation. The target of this research is to rigorously model and optimize the separation of water-ethanol-methanol ternary mixture in professional flowsheet simulator environment. The minimal sufficient membrane transfers area and number of minimal theoretical stages of the columns are determined. Cost estimation is also investigated according to Douglas methodology. Considering the simulation and economic results it can be determined that, the hybrid configuration is suitable for separation of ternary mixture in 99.5 weight percent purity.

Co-Hydrothermal gasification of Chlorella vulgaris and hydrochar: The effects of waste-to-solid biofuel production and blending concentration on biogas generation

This study investigates enhanced biogas production via co-Hydrothermal gasification (co-HTG) of wet Chlorella vulgaris biomass and hydrochar (HC). Hydrothermal carbonization was applied to valorize struvite containing waste microalgae stream into solid bio-fuel with improved combustion properties. The effects of HC quality and mixing ratio are investigated on biogas yield, composition and carbon conversion ratio. The results show that the application of blending components promotes H₂, CH₄ formation and selectivity in hydrothermal gasification. The total co-HTG gas yield is increased from 19.13 to 46.95 mol kg^-1 at 650 °C and 300 bar by applying 5 wt% HC blending concentration and reduced level of volatile matter content (24.61 wt%). The obtained high hydrogen, methane yields and carbon conversion ratio (19.49, 2.98 mol kg^-1, 82.31%, respectively) indicate effective hydrothermal upgrading potentials in case of wet and waste biomass feedstocks.

National Clinical Guidance for the Management of Cardiovascular Intervention in the COVID-19 Pandemic: From Bangladesh Society of Cardiovascular Interventions (BSCI)

Since the first recorded case of SARS-CoV-2 in Bangladesh on 8th March 2020, COVID-19 has spread widely through different regions of the country, resulting in a necessity to re-evaluate the delivery of cardiovascular services, particularly procedures pertaining to interventional cardiology in resource-limited settings. Given its robust capacity for human-to-human transmission and potential of being a nosocomial source of infection, the disease has specific implications on healthcare systems and health care professionals faced with performing essential cardiac procedures in patients with a suspected or confirmed diagnosis of COVID-19. The limited resources in terms of cardiac catheterization laboratories that can be designated to treat only COVID positive patients are further compounded by the additional challenges of unavailability of widespread rapid testing on-site at tertiary cardiac hospitals in Bangladesh. This document prepared for our nation by the Bangladesh Society of Cardiovascular Interventions (BSCI) is intended to serve as a clinical practice guideline for cardiovascular health care professionals, with a focus on modifying standard practice of care during the COVID-19 pandemic, in order to ensure continuation of adequate and timely treatment of cardiovascular emergencies avoiding hospital-based transmission of SARS-COV-2 among healthcare professionals and the patients. This is an evolving document based on currently available global data and is tailored to healthcare systems in Bangladesh with particular focus on, but not limited to, invasive cardiology facilities (cardiac catheterization, electrophysiology & pacing labs). This guideline is limited to the provision of cardiovascular care, and it is expected that specific targeted pharmaco-therapeutics against SARS-CoV-2 be prescribed as stipulated by the National Guidelines on Clinical Management of Corona virus Disease 2019 (COVID-19) published by the Director General of Health Services, Ministry of Health and Family Welfare of Bangladesh.

Pervaporation Performance of Ag-PVA Nanocomposite Membranes: Effect of Operating Temperature

The features of pervaporation are continuously improved with the production of more and more efficient membranes. In our present study, silver nanoparticles are in-situ generated in a poly (vinyl alcohol) using solution-casting in order to enhance its capability for pervaporation. The membrane is tested on the case study of ethanol dehydration by pervaporation. Effect of silver content on the pervaporation separation index and the enrichment factor of the membrane at 15 % mass water at 40 °C are reported. Pervaporation data for nanocomposite membranes show around 100 % increase in the water permeance values while the intrinsic selectivity decreases that is typical for pervaporation membranes. The water permeances of original crosslinked PVA membrane and the 2.5 % silver loaded PVA membrane are 26.65 and 70.45 (g/m2.kPa.h), respectively. The values of total flux are closely related to water flux, showing that membranes could be successfully assigned to separate water from ethanol even at the azeotropic point. The influence of temperature on the efficiency of the pervaporation process, permeation parameter and diffusion coefficient of the feed component is also discussed. The negative heat of sorption (∆Hs) values calculated on the basis of the estimated Arrhenius activation energy values indicates that the sorption process is controlled by Langmuir's mode. Our results show that the 0.5 mass% silver loaded poly (vinyl alcohol) membrane exhibits excellent PV performance.

Antibacterial activity of silver nanoparticles against field and reference strains of Mycobacterium tuberculosis, Mycobacterium bovis and multiple-drug-resistant tuberculosis strains

Tuberculosis (TB) is an endemic disease in animals and humans in Egypt. This study aims to investigate the antimycobacterial activity of silver nanoparticles(AgNPs) by determining the minimal inhibitory concentration (MIC) of AgNPs, using the microplate Alamar blue assay. The AgNPs were chemically synthesised and their form and size were characterised by ultraviolet-visible absorption spectrophotometry, transmission electron microscopy and X-ray diffraction.The reference strains of Mycobacterium bovis and Mycobacterium tuberculosisH37Rv, and one multiple-drug-resistant (MDR) strain of M. tuberculosis were tested, as well as clinical isolates of M. bovis and M. tuberculosis. The AgNPs were tetrahydral with a few spherical particles and an average particle size of 50 nm. The mycobacterial strains were varied with MICs of AgNPs. Both reference strains of M. tuberculosis and M. bovis, in addition to the MDR strain of M. tuberculosis, were successfully inhibited by AgNPs at MICs of 1 ?g/ml, 4 ?g/ml and 16 ?g/ml, respectively, whereas clinical isolates of M. bovis and M. tuberculosis were inhibited at MIC values of 4-32 ?g/ml and 1-16 ?g/ml, respectively. The AgNPs showed an in vitro chemotherapeutic effect against Mycobacterium spp.Thus, they can be used to treat TB not only in humans but also in animals, and maybe useful in TB prevention and control strategies worldwide.

Characterization of Coxiella burnetii strains from ruminants in a Galleria mellonella host-based model

Coxiella burnetii is a small Gram-negative intracellular bacterium and is the causative agent of Q fever, which is a zoonotic disease with a worldwide distribution. Domesticated ruminants are the main reservoir of the disease, but the bacterium is able to infect a wide range of hosts, including humans, arthropods and invertebrates. Virulence studies of Coxiella strains usually require a suitable animal model. However, mammalian models are costly and are associated with many ethical constraints. An alternative infection model using Galleria mellonella has been used to study the virulence of several bacterial as well as fungal pathogens. Moreover, the G. mellonella larvae model has been used to identify virulence genes using phase II C. burnetii strain Nine Mile mutants. In our study we describe its use for the characterization of C. burnetii strains isolated from ruminants.

Pathogenicity of the Egyptian A/H5N1 avian influenza viruses in chickens

Long-term circulation of highly pathogenic avian influenza H5N1 viruses of clade 2.2.1 in Egyptian poultry since February 2006 resulted in the evolution of two distinct clades: 2.2.1.1 represents antigenic-drift variants isolated from vaccinated poultry and 2.2.1.2 that caused the newest upsurge in birds and humans in 2014/2015. In the present study, nine isolates were collected from chickens, ducks and turkeys representing the commercial and backyard sectors during the period 2009-2015. The subtyping was confirmed by hemagglutination inhibition (HI) test, RT-qPCR and sequence analysis. The Mean Death Time (MDT) and Intravenous Pathogenicity Index (IVPI) for all isolates were determined. Sequence analysis of the HA gene sequences of these viruses revealed that two viruses belonged to clade 2.2.1.1 and the rest were clade 2.2.1.2. Antigenic characterisation of the viruses supported the results of the phylogenetic analysis. The MDT of the isolates ranged from 18 to 72 h and the IVPI values ranged from 2.3 to 2.9; viruses of the 2.2.1.1 clade were less virulent than those of the 2.2.1.2 clade. In addition, clade-specific polymorphism in the HA cleavage site was observed. These findings indicate the high and variable pathogenicity of H5N1 viruses of different clades and host-origin in Egypt. The upsurge of outbreaks in poultry in 2014/2015 was probably not due to a shift in virulence from earlier viruses.

Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation

Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country, affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used as a part of the control strategy to help to control the disease. Epidemiological data with sequence analysis of H5N1 viruses is important to link the mechanism of virus evolution in Egypt. This study describes the evolutionary pattern of Egyptian H5N1 viruses based on molecular characterization for the isolates collected from commercial poultry farms and village poultry from 2006 to 2011. Genetic analysis of the hemagglutinin (HA) gene was done by sequencing of the full-length H5 gene. The epidemiological pattern of disease outbreaks in Egyptian poultry farms seems to be seasonal with no specific geographic distribution across the country. The molecular epidemiological data revealed that there are two major groups of viruses: the classic group of subclade 2.2.1 and a variant group of 2.2.1.1. The classic group is prevailing mainly in village poultry and had fewer mutations compared to the originally introduced virus in 2006. Since 2009, this group has started to be transmitted back to commercial sectors. The variant group emerged by late 2007, was prevalent mainly in vaccinated commercial poultry, mutated continuously at a higher rate until 2010, and started to decline in 2011. Genetic analysis of the neuraminidase (NA) gene and the other six internal genes indicates a grouping of the Egyptian viruses similar to that obtained using the HA gene, with no obvious reassortments. The results of this study indicate that HPAI-H5N1 viruses are progressively evolving and adapting in Egypt and continue to acquire new mutations every season.

Avian influenza H5N1 virus infections in vaccinated commercial and backyard poultry in Egypt

In this paper, we describe results from a high-pathogenic H5N1 avian influenza virus (AIV) surveillance program in previously H5-vaccinated commercial and family-backyard poultry flocks that was conducted from 2007 to 2008 by the Egyptian National Laboratory for Veterinary Quality Control on Poultry Production. The real-time reverse transcription PCR assay was used to detect the influenza A virus matrix gene and detection of the H5 and N1 subtypes was accomplished using a commercially available kit real-time reverse transcription PCR assay. The virus was detected in 35/3,610 (0.97%) and 27/8,682 (0.31%) of examined commercial poultry farms and 246/816 (30%) and 89/1,723 (5.2%) of backyard flocks in 2007 and 2008, respectively. Positive flocks were identified throughout the year, with the highest frequencies occurring during the winter months. Anti-H5 serum antibody titers in selected commercial poultry ranged from <2 (negative) to 9.6 log(2) when determined in the hemagglutination inhibition test using a H5 AIV antigen. In conclusion, despite the nationwide vaccination strategy of poultry in Egypt to combat H5N1 AIV, continuous circulation of the virus in vaccinated commercial and backyard poultry was reported and the efficacy of the vaccination using a challenge model with the current circulating field virus should be revised.

The Egyptian National Breast Screening Program: Priorities, challenges, and results of the pilot phase

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Background: According to the World Health Organization,the number of breast cancercases in developing countries will increase dramatically by the year 2050. Egypt is likely to see an increase in this disease burden unless effective programs for early detection and control are implemented. Many women, especially those who are medically underserved, still do not understand the importance of regular mammograms, or how and where to get one. Methods: Four mobile mammography vans were launched in October 2007, to screen women over 45 years old in the underserved areas of Cairo. Each van was equipped with a full field digital mammography (FFDM) machine, dedicated computer system linked to the National Breast Screening Center via video SAT & ADSL, sphygmomanometer, blood glucose measuring kit, and spring scale and meter to measure weight and height. Based on positive findings, patients were directed to Cairo University Hospital to receive appropriate treatment. Mobile units continued to operate through October, 2008. Results: From October 2007 through October 2008, 11,414 women were screened for breast cancer, hypertension, diabetes, and obesity. Two hundred forty four (2.13%) women were radiologically positive for cancer; of these, only 112 (45.9%) women agreed to be recalled for assessment; of these, 49.1% were confirmed to be true positive with BI-RADS 4,5 (61% cases were mass, with 27.9 % 1–2 cm in size; 16.4% cases were microcalcifications alone; multicentricity in 6.6 %; bilaterality in 2.5% of cases). 36.6% were false positive, and 14.2% are under further investigation. Conclusions: Although Cairo is the most developed city in Egypt, there is lack of breast cancer awareness, especially in the underserved areas. Breast cancer is now a priority for the Ministry of Health, with four more vans and 10 fixed FFDM units to be implemented during the next year. A 5-year plan has been established to cover all 29 Egyptian Governorates.

No significant financial relationships to disclose.

A Telephone-Linked Computer System for COPD Care

The current revolution in communications technology provides an opportunity for novel approaches to management of medical illness. As economic imperatives lead to a progressive reduction in the time that health-care providers spend with their patients, computerized, telephone-linked communication systems offer an inexpensive, widely available alternative with which patients and providers can maintain contact. Such systems may be particularly useful for providing ongoing monitoring and education of patients with chronic illnesses such as COPD. In this article, we describe the general application of telephone-linked communication systems in the health-care setting. We then present in detail one such system, which provides telephone-linked care for COPD (TLC-COPD). The operation of the system is described, as are its theoretical underpinnings in social learning theory. A randomized clinical trial currently is being performed to study the effects of the TLC-COPD system. The rationale for expected improvements in disease control and quality of life, and for a reduction in acute health-care utilization, is discussed.

A telecommunications system to manage patients with chronic disease

The care of patients with chronic disease is a large and growing problem in the United States and other industrialized countries.' it is expensive, and the quality of care received by patients is often sub-optimal, resulting in poor health outcomes. We developed a totally automated computer-controlled telecommunications system, called TLC, that provides--frequent, close monitoring of patients with chronic disease and reports the results to the patients' physicians on a timely basis, so that they can intervene appropriately. TLC also monitors the patients' important self care activities, such as medication-taking, and provides education and counseling to improve the patients' performance of these activities. The system operates through regularly scheduled telephone conversations with patients' in their homes. An evaluation of a TLC chronic disease application for patients with hypertension demonstrated that use of the system was associated with significant improvement of the patients' adherence to their medication regimens and significantly improved blood pressure control. These results show that it is possible to design an information science-based health care delivery system that performs functions usually performed only by health care professionals, and suggests that information science will become an important means of delivering health care services in the next millennium.

Microscopic localization of calcifications in and around breast carcinoma: a cautionary note for needle core biopsies

OBJECTIVE

To detail the microanatomic localization of microcalcifications (Ca++) occurring in association with breast carcinoma and thereby to determine their reliability as a marker of breast carcinoma in small tissue core biopsies.

SUMMARY BACKGROUND DATA

Identification of the pathology associated with Ca++ in mammograms has acquired increasing importance in the early detection of breast carcinoma. With recent advances enabling computer-guided stereoscopic needle biopsy of calcified foci, histopathologic diagnosis is rendered on increasingly small tissue samples, raising the risk of misdiagnosis. Knowledge of the microanatomic distribution of Ca++ in relation to diagnostic epithelial elements is essential for assessing their significance in small tissue biopsies.

METHODS

All 32 carcinomas with Ca++ within 1 cm of carcinoma diagnosed by open biopsy at the New England Deaconess Hospital from January 1994 to January 1995 were studied. Ca++ were classified as being within ductal or lobular carcinoma in situ, invasive carcinoma, carcinoma-associated stroma, benign stroma >1 mm from carcinoma, or benign ducts or terminal duct-lobular units. If Ca++ were peritumoral, their distance from the tumor was measured.

RESULTS

Ca++ were present only in malignant components in 31%, only in benign components in 34%, and in both in 34% of cases. The most common locations of Ca++ were benign peritumoral ducts (62%) and ductal carcinoma in situ (54%). The microanatomic distribution of benign peritumoral Ca++ in relation to the mass is detailed.

CONCLUSIONS

In carcinomas with Ca++ in the area of tumor, Ca++ may not be localized to malignant tissue. Caution should be used when interpreting the finding of Ca++ in benign components of small tissue samples of breast masses.

Health-related quality of life in patients served by the Department of Veterans Affairs: results from the Veterans Health Study

BACKGROUND

The Department of Veterans Affairs Health Care System (VA) is the largest integrated single payer system in the United States. To date, there has been no systematic measurement of health status in the VA. The Veterans Health Study has developed methods to assess patient-based health status in ambulatory populations.

OBJECTIVES

To describe the health status of veterans and examine the relationships between their health-related quality of life, age, comorbidity, and socioeconomic and service-connected disability status.

METHODS

Participants in the Veterans Health Study, a 2-year longitudinal study, were recruited from a representative sample of patients receiving ambulatory care at 4 VA facilities in the New England region. The Veterans Health Study patients received questionnaires of health status, including the Medical Outcomes Study Short Form 36-Item Health Survey; and a health examination, clinical assessments, and medical history taking. Sixteen hundred sixty-seven patients for whom we conducted baseline assessments are described.

RESULTS

The VA outpatients had poor health status scores across all measures of the Medical Outcomes Study Short Form 36-Item Health Survey compared with scores in non-VA populations (at least 50% of 1 SD worse). Striking differences also were found with the sample stratified by age group (20-49 years, 50-64 years, and 65-90 years). For 7 of the 8 scales (role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health), scores were considerably lower among the younger patients; for the eighth scale (physical function), scores of the young veterans (aged 20-49 years) were almost comparable with the levels in the old veterans (>65 years). The mental health scores of young veterans were substantially worse than all other age groups (P<.001) and scores of screening measures for depression were significantly higher in the youngest age group (51%) compared with the oldest age groups (33% and 16%) (P<.001).

CONCLUSIONS

The VA outpatients have substantially worse health status than non-VA populations. Mental health differences between the young and old veterans who use the VA health care system are sharply contrasting; the young veterans are sicker, suggesting substantially higher resource needs. Mental health differences may explain much of the worse health-related quality of life in young veterans. As health care systems continue to undergo a radical transformation, the Department of Veterans Affairs should focus on the provision of mental health services for its younger veteran.

Attentional performance of children with traumatic brain injury: a quantitative and qualitative analysis of digit span

Previous studies have indicated that digit span performance is not particularly sensitive to the effects of traumatic brain injury (Baddeley & Warrington, 1970; Brooks, 1975; Sterne, 1969). However, clinical lore posits poorer backward vs. forward performance compared to normals due to the greater attentional demands of the backward task. This study examined qualitative aspects of Digit Span performance including forward/backward span discrepancies and error patterns in children with traumatic brain injury (n = 20) and normals (n = 19). The hypothesis of greater forward/backward discrepancy with traumatic brain injury was not supported. Children with traumatic brain injury make a significantly greater number of preceiling errors than normals, consistent with other findings of increased performance variability. Preceiling errors are errors that occur in trials prior to the two failed trials, resulting in discontinuation of the task. In addition, cognitive correlates of error types, such as WISC-R factor scores, were significantly different between groups. The results of this study suggest that a more detailed analysis of performance on attentional tasks previously described as resilient to brain injury may shed further light on the nature of acquired attentional deficits.

Detection of herpes simplex virus DNA in cerebrospinal fluid of Saudi pediatric patients with encephalitis by the polymerase chain reaction

Twelve samples of cerebrospinal fluid (CSF) from Saudi pediatric patients with suspected encephalitis were found negative for herpes simplex virus by cell culture and by nucleic acid hybridization using(32)P-labeled specific probes. After amplification of DNA extracted from 100 microl of each sample using primers for the glycoprotein D gene of HSV, seven specimens were found positive for HSV DNA. Subsequent hybridization with the labeled DNA probe ensured the positivity of the seven samples and further detected one more positive sample, for a total of eight HSV DNA positive cases. This technique improved the detection of HSV in CSF samples and may assist in an early diagnosis for HSV ecephalitis.

A simple procedure for the isolation of schistosomules for biochemical studies or culture

Incubation of cercariae of Schistosoma mansoni in a 1:1 mixture of Eagle's Minimal Essential Medium and rat serum at 42 degrees C for only 5 minutes, plus subsequent vortexing, resulted in at least 98% conversion of cercariae to schistosomules. Subsequent centrifugation before or after settling for 30 minutes in an ice bath, resulted in schistosomule preparations with about 20% or 10% contamination with tail segments, respectively.

The potential role of various species of intermediate hosts of Schistosoma haematobium in Saudi Arabia

The potential role of 3 species of Bulinus in the transmission of Schistosoma haematobium in Saudi Arabia was assessed on the basis of their susceptibility to experimental infection, their geographical distribution and numbers, and the type of habitats in which they were found. B. truncatus, distributed mainly in the mid- and south-western regions, showed extremely low susceptibility to strains of S. haematobium from Yemen, Egypt and Sudan. The same species from one area in the north-west was refractory to a strain of the parasite from Yemen. In contrast, B. wrighti was very susceptible to infection but is found only in a few habitats far from human settlements, thus probably playing little part in the transmission of the disease. As B. beccarii is highly susceptible to the infection and is distributed widely, this snail is probably the main intermediate host of schistosomiasis in Saudi Arabia.

Keratoconus, magnesium deficiency, type A behavior, and allergy

The etiology of keratoconus is still unknown. This project was designed to study, in a group of keratoconic patients and a control group, the following: clinical, endocrinological, immunological, psychological, and ophthalmological factors. We found mean serum magnesium deficiency and type A behavior to be significantly more common in keratoconic patients than in a control group of patients. In addition changes in gluco-mineral corticoids, changes in glucose metabolism, edema of allergic origin, and genetic factors may collaborate in the development of keratoconus. All these factors could affect the osmotic mechanism of the cornea: Na-K and/or Ca ATPase, the collagen structure by alteration of the adenylate cyclase activity, and other mechanisms. This study suggests an association between keratoconus, magnesium depletion, and type A behavior, which together constitute a new clinical syndrome and confirm an association between keratoconus and atopy.