Extracellular acidosis enhances Zika virus infection both in human cells and ex-vivo tissue cultures from female reproductive tract

Zika virus (ZIKV) is a flavivirus transmitted by mosquitoes of the genus Aedes, but unlike other flaviviruses, ZIKV can be sexually transmitted by vaginal intercourse. The healthy vaginal pH ranges from 4.0 to 6.0, reaching values of 6.0-7.0 after semen deposition. Here, we report that low extracellular pH values (range 6.2-6.6) dramatically increase ZIKV infection on cell lines of different origin including some derived from the female genital tract and monocyte-derived macrophages. Furthermore, low pH significantly increased ZIKV infection of human ectocervix and endocervix cultured ex-vivo. Enhancement of infection by low pH was also observed using different ZIKV strains and distinct methods to evaluate viral infection, i.e. plaque assays, RT-PCR, flow cytometry, and fluorescence microscopy. Analysis of the mechanisms involved revealed that the enhancement of ZIKV infection induced by low pH was associated with increased binding of the viral particles to the heparan sulphate expressed on the target cell surface. Acidosis represents a critical but generally overlooked feature of the female genital tract, with major implications for sexual transmission diseases. Our results suggest that low vaginal pH might promote male-to-female transmission of ZIKV infection.

[Percutaneous implantation of an aortic prosthetic valve on a degenerated mitral bioprosthesis. Report of one case]

Reintervention of a mitral degenerated bioprosthesis has a high surgical risk, especially in elderly patients with multiple comorbidities. We report a 74 years old female with two previous cardiac surgical procedures and a new structural mitral bioprosthesis deterioration with severe mitral regurgitation. Considering her high-surgical risk, a fully percutaneous treatment was performed with a balloon-expandable aortic valve in mitral position (valve-in-valve) through a transseptal approach with a favorable outcome. This technique is an attractive and effective option with a relatively low rate of complications that could solve this challenging and complex disease.

Exposure to bisphenol A differentially impacts neurodevelopment and behavior in Drosophila melanogaster from distinct genetic backgrounds

Bisphenol A (BPA) is a ubiquitous environmental chemical that has been linked to behavioral differences in children and shown to impact critical neurodevelopmental processes in animal models. Though data is emerging, we still have an incomplete picture of how BPA disrupts neurodevelopment; in particular, how its impacts may vary across different genetic backgrounds. Given the genetic tractability of Drosophila melanogaster, they present a valuable model to address this question. Fruit flies are increasingly being used for assessment of neurotoxicants because of their relatively simple brain structure and variety of measurable behaviors. Here we investigated the neurodevelopmental impacts of BPA across two genetic strains of Drosophila-w¹¹¹⁸ (control) and the Fragile X Syndrome (FXS) model-by examining both behavioral and neuronal phenotypes. We show that BPA induces hyperactivity in larvae, increases repetitive grooming behavior in adults, reduces courtship behavior, impairs axon guidance in the mushroom body, and disrupts neural stem cell development in the w¹¹¹⁸ genetic strain. Remarkably, for every behavioral and neuronal phenotype examined, the impact of BPA in FXS flies was either insignificant or contrasted with the phenotypes observed in the w¹¹¹⁸ strain. This data indicates that the neurodevelopmental impacts of BPA can vary widely depending on genetic background and suggests BPA may elicit a gene-environment interaction with Drosophila fragile X mental retardation 1 (dFmr1)-the ortholog of human FMR1, which causes Fragile X Syndrome and is associated with autism spectrum disorder.

Reconfigurable ferromagnetic liquid droplets

Solid ferromagnetic materials are rigid in shape and cannot be reconfigured. Ferrofluids, although reconfigurable, are paramagnetic at room temperature and lose their magnetization when the applied magnetic field is removed. Here, we show a reversible paramagnetic-to-ferromagnetic transformation of ferrofluid droplets by the jamming of a monolayer of magnetic nanoparticles assembled at the water-oil interface. These ferromagnetic liquid droplets exhibit a finite coercivity and remanent magnetization. They can be easily reconfigured into different shapes while preserving the magnetic properties of solid ferromagnets with classic north-south dipole interactions. Their translational and rotational motions can be actuated remotely and precisely by an external magnetic field, inspiring studies on active matter, energy-dissipative assemblies, and programmable liquid constructs.

Seminal vesicle fluid increases the efficacy of intravaginal HSV-2 vaccination

Once considered merely as a vehicle for spermatozoa, it is now clear that seminal plasma (SP) induces a variety of biological actions on the female reproductive tissues able to modulate the immune response against paternal antigens. To our knowledge, the influence of SP on the immune response against sexually transmitted pathogens has not been yet evaluated. We here analyzed whether the seminal vesicle fluid (SVF), which contributes almost 60% of the SP volume in mice, could modulate the immune response against herpes simplex virus type 2 (HSV-2). We found that SVF does not modify the course of primary infection, but markedly improved protection conferred by vaginal vaccination with inactivated HSV-2 against a lethal challenge. This protective effect was shown to be associated to a robust memory immune response mediated by CD4+ and CD8+ T cells in both the lymph nodes draining the vagina and the vaginal mucosa, the site of viral replication. In contrast with the widespread notion that SP acts as an immunosuppressive agent, our results suggest that SVF might improve the female immune response against sexually transmitted pathogens.

Acetylcholine polarizes dendritic cells toward a Th2-promoting profile

BACKGROUND

A growing body of research shows a reciprocal regulation between the neural and immune systems. Acetylcholine (ACh) is the most important parasympathetic neurotransmitter, and increasing evidence indicates that it is able to modulate the immune response. Interestingly, in recent years, it has become clear that immune cells express a non-neuronal cholinergic system, which is stimulated in the course of inflammatory processes. We have previously shown that dendritic cells (DC) express muscarinic receptors, as well as the enzymes responsible for the synthesis and degradation of ACh. Here, we analyzed whether ACh could also modulate the functional profile of DC.

METHODS

Dendritic cells were obtained from monocytes cultured for 5 days with GM-CSF+IL-4 or isolated from peripheral blood (CD1c+ DC). The phenotype of DC was evaluated by flow cytometry, the production of cytokines was analyzed by ELISA or intracellular staining and flow cytometry, and the expression of muscarinic and nicotinic receptors was evaluated by flow cytometry or qRT-PCR.

RESULTS

Treatment of DC with ACh stimulated the expression of the Th2-promoter OX40L, the production of the Th2-chemokines MDC (macrophage-derived chemokine/CCL22) and TARC (thymus and activation-regulated chemokine/CCL17), and the synthesis of IL-4, IL-5, and IL-13 by T cells, in the course of the mixed lymphocyte reaction (MLR). Moreover, we found that the stimulation of OX40L, HLA-DR, and CD83 expressions in DC induced by the Th2-promoting cytokine TSLP, as well as the production of IL-13, IL-4, and IL-5 by T cells in the course of the MLR, was further enhanced when DC were treated with TSLP plus ACh, instead of TSLP or ACh alone.

CONCLUSIONS

Our observations suggest that ACh polarizes DC toward a Th2-promoting profile.

Evaluation of the efficacy of intramuscular versus intramammary treatment of subclinical Streptococcus agalactiae mastitis in dairy cows in Colombia

A randomized controlled trial was performed in 17 Colombian dairy herds to determine the cure risk among cows subclinically infected with Streptococcus agalactiae exposed to 2 antibiotic therapies. Composite milk samples were collected before milking at the onset of the trial (pretreatment) and 2 subsequent times over a period of approximately 63 d. The intramammary application (IMM) of ampicillin-cloxacillin was compared with the intramuscular application (IM) of penethamate hydriodide, and cure risks after an initial and retreatment application were assessed. Cure risk after the initial treatment was higher (82.4%) for the IMM treatment than for IM therapy (65.8%). However, no difference was observed in the cure risk of refractory cases after retreatment (IMM=52.6% vs. IM=51.2%). The cumulative cure risk (both initial and retreatment) was 90.4 and 82.9% for the IMM and IM products, respectively. A 2-level random effects logistic model that controlled for pretreatment cow-level somatic cell count, indicated that IM treatment (odds ratio=0.37) had a lower cure risk than IMM and a tendency for a lower cure risk with increasing baseline somatic cell count. Our findings suggest that both products and administration routes can reduce the prevalence of S. agalactiae in affected herds, but the IMM product had a better efficacy in curing the infection. In addition to the treatment protocol, the cow somatic cell count should be considered when making management decisions for cows infected with S. agalactiae.

Fucosylated clusterin in semen promotes the uptake of stress-damaged proteins by dendritic cells via DC-SIGN

STUDY QUESTION

Could seminal plasma clusterin play a role in the uptake of stress-damaged proteins by dendritic cells?

SUMMARY ANSWER

Seminal plasma clusterin, but not serum clusterin, promotes the uptake of stress-damaged proteins by dendritic cells via DC-SIGN.

WHAT IS KNOWN ALREADY

Clusterin is one of the major extracellular chaperones. It interacts with a variety of stressed proteins to prevent their aggregation, guiding them for receptor-mediated endocytosis and intracellular degradation. The concentration of clusterin in semen is almost 20-fold higher than that found in serum, raising the question about the role of seminal plasma clusterin in reproduction. No previous studies have analyzed whether seminal plasma clusterin has chaperone activity. We have previously shown that seminal plasma clusterin, but not serum clusterin, expresses an extreme abundance of fucosylated glycans. These motifs enable seminal plasma clusterin to bind DC-SIGN with very high affinity.

STUDY DESIGN, SIZE, DURATION

In vitro experiments were performed to evaluate the ability of seminal plasma clusterin to inhibit the precipitation of stressed proteins, promoting their uptake by dendritic cells via DC-SIGN (a C-type lectin receptor selectively expressed on dendritic cells (DC)). Moreover, the ability of seminal plasma clusterin to modulate the phenotype and function of DCs was also assessed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clusterin was purified from human semen and human serum. Catalase, bovine serum albumin, glutathione S-transferase, and normal human serum were stressed and the ability of seminal plasma clusterin to prevent the precipitation of these proteins, guiding them to DC-SIGN expressed by DCs, was evaluated using a fluorescence-activated cell sorter (FACS). Endocytosis of stressed proteins was analyzed by confocal microscopy and the ability of seminal plasma clusterin-treated DCs to stimulate the proliferation of CD25+FOXP3+CD4+ T cells was also evaluated by FACS.

MAIN RESULTS AND THE ROLE OF CHANCE

Seminal plasma clusterin interacts with stressed proteins, inhibits their aggregation (P < 0.01) and efficiently targets them to dendritic cells via DC-SIGN (P < 0.01). DCs efficiently endocytosed clusterin-client complexes and sorted them to degradative compartments involved in antigen processing and presentation. Moreover, we also found that the interaction of seminal plasma clusterin with DC-SIGN did not change the phenotype of DCs, but stimulates their ability to induce the expansion of CD25+FOXP3+CD4+ T lymphocytes (P < 0.05 versus control).

LIMITATIONS, REASONS FOR CAUTION

All the experiments were performed in vitro; hence the relevance of our observations should be validated in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that by inducing the endocytosis of stress-damaged proteins by DCs via DC-SIGN, seminal plasma clusterin might promote a tolerogenic response to male antigens, thereby contributing to female tolerance to seminal antigens.

STUDY FUNDING/COMPETING INTERESTS

The present research was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas, the Buenos Aires University School of Medicine, and the Agencia Nacional de Promoción Científica y Tecnológica (Argentina). The authors have no conflicts of interest to declare.

[Systematic Review of Factors Associated with the Presence of Cytoplasmic Droplets in Boars]

OBJECTIVE

To determine the factors associated with the presence of cytoplasmic droplets in boars.

METHODS

A systematic review was carried out in which 133 articles were found, 70 were eliminated due to duplication, and 65 were finally selected: 57 in Cab Abstract, 39 in Pub Med, 20 in Agricola, and 17 in Science Direct. Forty-seven articles were found with an available full text. Data was tabulated in EpiData Entry and transferred to the Stata version 12.0 program.

RESULTS

Factors Associated with cytoplasmic droplets are: Climatic and environmental variables; ejaculation frequency with intervals of less than three weeks; spermatic morphologic alterations in tail (coiled and distal reflex); DNA fragmentation; and enzymatic factors related to seminal biochemistry. Work carried out in equatorial climate regions or that focused on the analysis of the implications of CDs in artificial insemination centers was not found.

CONCLUSIONS

The information is characterized by a wide heterogeneity and diversity studies. A contribution was made to Veterinary Public Health in Colombia on the importance of CGs as factors that limit reproductive processes in swine. It was not possible to determine the temporal relationship between the cause and effect of CDs.

Prostaglandins in semen compromise the immune response against sexually transmitted pathogens

Seminal plasma is not just a spermatozoa carrier. It induces the expression of inflammatory cytokines and chemokines and a massive infiltration of neutrophils, monocytes and dendritic cells in the female genital mucosa after coitus, enabling the innate immune system to fight against sexually transmitted pathogens. However, exposure to seminal plasma not only turns on an inflammatory response but also induces regulatory mechanisms that allow the fetus (a semiallograft) to grow and develop in the uterus. In mouse models it has been shown that seminal plasma induces the expansion of regulatory T cells specific to seminal Ags in the receptive partner, thus promoting tolerance to paternal alloantigens and avoiding allogeneic fetal rejection. These mechanisms appear to be mainly induced by prostaglandins of the E series (PGE) and TGF-β, which are present at huge concentrations in the seminal plasma. Moreover, we have recently shown that exposure to seminal plasma induces the differentiation of dendritic cells into a tolerogenic profile through a mechanism dependent on the activation of the prostanoid receptors EP2 and EP4 by seminal PGE. Our hypothesis proposes that this tolerogenic response induced by seminal PGE, while promoting fertility by inducing tolerance toward paternal alloantigens, might also compromise the development of the adaptive immune response against sexually transmitted pathogens in the receptive partner.

High spatial resolution Raman thermometry analysis of TiO2 microparticles

A new technique of high-resolution micro-Raman thermometry using anatase TiO2 microparticles (0.5-3 μm) is presented. These very high spatial resolution measurements (280 nm) reveal temperature gradients even within individual microparticles. Potential applications of this technique are demonstrated by probing the temperature distribution of a micro-fabricated heater consisting of a thin silicon nitride (Si-N) membrane with a gold coil on top of the membrane. Using TiO2 microparticle micro-Raman thermometry, the temperature from the outer edge of the coil to the inner portion was measured to increase by ~40 °C. These high spatial resolution microscopic measurements were also used to measure the temperature gradient within the 20 μm wide Si-N between the gold heating coils. 2D numerical simulations of the micro heater temperature distribution are in excellent agreement with the experimental measurements of the temperatures. These measurements illustrate the potential to extend applications of micro-Raman thermometry to obtain temperature details on a sub-micrometer spatial resolution by employing microparticles.

Barium selenate supplementation and its effect on intramammary infection in pasture-based dairy cows

A significant proportion of cattle receive inadequate dietary Se because of its low content in soils and pastures of various regions of the world. Several economically important diseases in dairy cows, such as mastitis, have been associated with Se deficiency. The objective of this study was to evaluate the effect of a single injection of a long-acting form of Se at drying off on the risk and incidence rate of new intramammary infections and on milk somatic cell count in the subsequent lactation in pasture-based dairy cows. Forty-nine Chilean Holstein-Friesian cows were fed a diet containing <0.05 mg of Se/kg of ration dry matter. During the dry period, cows were allocated to 1 of 2 groups, a supplemented (n=24) group treated with a single subcutaneous injection of barium selenate 2 mo before calving and a control group (n=25) that remained unsupplemented. Duplicate foremilk samples were aseptically collected within 6 d after calving and every 2 wk until drying-off for bacteriological culture. Milk samples were also collected monthly for somatic cell count evaluation. Blood samples were collected before treatment and at 30, 90, 180, and 270 d after treatment for analysis of blood glutathione peroxidase (GPx) activity. The activity of glutathione peroxidase was higher in supplemented cows 30 d after the injection until the end of the study. The risk and incidence rate of new intramammary infections was not affected by supplementation. A progressive increase in somatic cell count was observed throughout lactation, but there was no effect of supplementation. In conclusion, a one-time injection of barium selenate 2 mo before calving in these pasture-based dairy cows did not affect udder health in the subsequent lactation, indicating that Se basal intake was adequate for preventing subclinical mastitis in pasture-based cows in southern Chile.

Somatic cell count in milk of selenium-supplemented dairy cows after an intramammary challenge with Staphylococcus aureus

The objective of this study was to evaluate the effect of selenium (Se) supplementation on milk somatic cell count (SCC) in dairy cows. Twelve multiparous Holstein-Friesian cows were fed a diet containing a suboptimal Se concentration (<0.05 ppm, dry basis) starting 2 months before calving. Supplemented cows (n=6) received a single s.c. injection of barium selenate (1 ml/50 kg BW) 45 days prior to calving, whereas control group was kept unsupplemented. Twenty weeks after calving, two mammary quarters (right side) of each cow were challenged with 205,000 cfu/ml of Staphylococcus aureus (strain Newbould 305). Blood was collected bi-weekly until day 150 of lactation for the analysis of blood glutathione peroxidase (GPx1; EC 1.11.1.9) activity. To re-isolate the challenging pathogen and to evaluate SCC, aseptic milk samples were collected daily starting on the day of challenge, and finishing 7 days after inoculation. Unsupplemented cows had a lower activity of GPx1 through the experiment (P<0.001). Natural log SCC (lnSCC) was higher in unsupplemented than Se-supplemented cows (P=0.04), showing evidence of significance after 5 days. Selenium supplementation of dairy cows fed a diet containing a suboptimal Se concentration, resulted in higher blood activity of GPx1, and lower mean lnSCC after an intramammary challenge with Staph. aureus.

Viral reactivation and pseudotype production in an in vitro superinfection system with two different strains of HIV-1

Viral production and variability of HIV-1 is normally high in vivo causing the necessary conditions for cellular superinfection. In order to evaluate the superinfection dynamics in vitro, H9HTLVIIIB cell line was superinfected with HIVMN. Superinfected cells showed nearly 50% cell mortality at day 1 post-superinfection (ps), which increased significantly up to day 4 ps. Superinfecting genome was detectable until day 10 ps. The superinfecting strain was found in the supernatant only on day 1 ps, but was recovered up to day 4 ps by coculture with non-infected cells. The existing strain (HIVHXB2) was recovered throughout the studied period. Pseudotype formation by the HIVHXB2 genome and envelope proteins of the superinfecting strain (HIVMN) was observed from day 1 to 6 ps. Viral production was increased by 1.7 LOG in superinfected cells from day 1 ps. Both viral production increase and pseudotype formation could be relevant for HIV pathogenesis in vivo.

Influence of formulation and process variables on in vitro release of theophylline from directly-compressed Eudragit matrix tablets

Extended-release theophylline (TP) matrix tablets were prepared by direct compression of drug and different pH-dependent (Eudragit L100, S100 and L100-55) and pH-independent (Eudragit RLPO and RSPO) polymer combinations. The influence of varying the polymer/polymer (w/w) ratio and the drug incorporation method (simple blend or solid dispersion) was also evaluated. Drug release, monitored using the Through Flow Cell system, markedly depended on both the kind of Eudragit polymer combinations used and their relative content in the matrix. Maintaining a constant 1:1 (w/w) drug/polymers ratio, the selection of appropriate mixtures of pH-dependent and pH-independent polymers enabled achievement of a suitable control of TP release. In particular, matrices with a 0.7:0.3 w/w mixture of Eudragit L100-Eudragit RLPO showed highly reproducible drug release profiles, with an almost zero-order kinetic, and allowed 100% released drug after 360 min. As for the effect of the drug incorporation method, simple blending was better than the solid dispersion technique, which not only did not improve the release data reproducibility, but also caused, unexpectedly, a marked slowing down in drug release rate.

Control of hypertension in patients at high risk of cardiovascular disease

BACKGROUND

Hypertension is a major cardiovascular risk factor, but knowledge about the real magnitude of the problem and its determinants is lacking.

AIM

To assess control of hypertension and evaluate medical resource use, in patients at high risk of cardiovascular disease.

DESIGN

Multicentric cross-sectional study.

METHODS

We collected data for 2205 adult patients from 36 centres, representative of all regions of Spain. Patients had attended out-patient clinics from July 2002 to August 2003, had an absolute cardiovascular risk > or =20% at 10 years (according to the Framingham guidelines), and had a diagnosis of hypertension. Pregnant and terminally ill patients were excluded.

RESULTS

Hypertension was inadequately controlled in 1384 patients (62.8%). LDL cholesterol was higher in patients with uncontrolled hypertension (median 130.2 vs. 120.0 mg/dl, p < 0.001). Haemoglobin A(1c) in diabetic patients was also greater in those with uncontrolled hypertension (median 7.10% vs. 6.90%, p = 0.010). Uncontrolled hypertension was associated with the following variables, in descending strength of association: higher LDL cholesterol, taking antihypertensive medication, living in non-metropolitan areas, and higher body mass index.

DISCUSSION

Hypertension is poorly controlled in most patients with a high risk of cardiovascular disease. Uncontrolled hypertension is frequently associated with poor control of other risk factors.

The effect of D-003 (10 mg/day) on biochemical parameters of bone remodelling in postmenopausal women: a randomized, double-blind study

Biphosphonates, which are antiresorptive agents used to treat osteoporosis, inhibit the mevalonate pathway, preventing protein prenylation and inhibiting osteoclast activity. Statins decrease cholesterol biosynthesis by blocking the mevalonate pathway and have been reported to have beneficial effects on bone. D-003 is a mixture of high molecular weight acids purified from sugarcane wax that inhibits cholesterol biosynthesis before mevalonate production. D-003 prevents bone loss and resorption in rats with osteoporosis induced with ovariectomy or corticoids. Biochemical markers of bone turnover are used to monitor the short-term efficacy of antiosteoporotic therapy. This randomized, double-blind, placebo-controlled study was undertaken to investigate the short-term effects of D-003 (10 mg/day) on biochemical markers of bone turnover in postmenopausal women with low bone mineral density (BMD). After 4 weeks on a low-fat diet, 34 women were randomized to D-003 (10 mg/day) or placebo for 6 months. Pre- and post-treatment samples were analyzed for urinary excretion of deoxypyridinoline (DPD)/creatinine (Cr), a marker of bone resorption, and serum bone specific alkaline phosphatase (BSAP), a marker of bone formation. The effects on lipid profile and safety indicators, as well as adverse events (AE), were investigated. D-003 (10 mg/day) lowered urinary excretion of tDPD/Cr versus baseline (20.6%) (p < 0.001) and placebo (33.7%) (p < 0.01), but did not modify serum BSAP. D-003 decreased low-density lipoprotein-cholesterol (LDL-C) (32.8%), total cholesterol (TC) (16.4%) and the TC/high-density lipoprotein-cholesterol (HDL-C) ratio (34.7%), increased HDL-C (30.3%) (p < 0.001) and did not modify triglycerides. The effects on these variables were significant as early as 3 months after treatment initiation. D-003 was well tolerated. Three patients (one in the placebo group and two in the D-003 group) withdrew from the study. Two of these withdrawals were due to AE: abdominal pain (placebo) and heartburn (D-003). Five patients (four in the placebo group [22.2%] and one in the D-003 group [6.3%]) reported mild AE. In conclusion, D-003 (10 mg/day) reduced urinary excretion of tDPD/Cr, a bone resorption marker and did not change serum BSAP, a bone formation marker, while it lowered cholesterol in study patients. These preliminary results suggest that D-003 could be useful in treating postmenopausal women with low BMD. However, the potential value of D-003 in treating or preventing osteoporosis deserves further clinical investigation.

Improving stall design: use of 3-D kinematics to measure space use by dairy cows when lying down

Uncomfortable stalls reduce the time cows spend resting and are a risk factor for lameness. Although recommendations for stall dimensions are available, little research supports these recommendations. In this study, kinematic techniques were used to provide the first accurate measures of space used by Holstein dairy cows during lying-down movements in an open space and in a free stall. Cows (n=5, mean parity 3.2 +/- 1.0, body weight=607 +/- 21 kg) used up to 300 cm of longitudinal space when lying down, more than is typically provided by current industry recommendations for stall length. Cows used up to 109 cm of lateral space (180% of hip width), an estimate that is within current recommendations for stall width. During the lying-down movement, maximal lateral displacements at the hip occurred in two vertical zones: one between 95 and 135 cm, and the second less than 50 cm above the lying surface. Maximal longitudinal displacements of the nose were clustered 10 to 30 cm above the surface. These heights should be taken into account when designing and positioning stall partitions. Maximum instantaneous velocity of body markers approached 220 cm/s, indicating that cows can contact inappropriately placed stall partitions and the lying surface with considerable force. Kinematic techniques are promising ways of assessing spatial requirements of cattle to improve stall design. Further work is required to assess a wider range of cow sizes and stall configurations.

Oxytocin and prostaglandins F2alpha and E2 do not enhance HIV antigen production in vitro

Oxytocin and prostaglandins (PGs) are hormones involved in labor and are used clinically for its induction. In this study the effect of oxytocin, PGF(2alpha), and PGE(2) on Humour immunodeficiency virus-1 production in acutely and persistently infected cells was measured. No significant effect on p24 antigen production was found with oxytocin or PGs, except for a transient decrease in persistently infected cells treated with 1 micro M PGF(2alpha). These results showed that oxytocin and PGs could be used clinically for labor induction without any direct enhancement in viral production. Besides, the results with PGF(2alpha) at the highest concentration studied may indicate a pharmacological effect.

[Streptococcus pneumoniae: evolution of antibiotic resistance in a pediatric hospital in Córdoba, Argentina]

The wide variety of prevalence of antimicrobial resistant Streptococcus pneumoniae in different countries confirms the importance of determining local patterns of resistance. From 1992 to 2000, we studied the pattern of antimicrobial resistance in S. pneumoniae and its evolution along the years, using 468 strains isolated in the Hospital de Niños de Córdoba. A total of 177 isolates (37.8%) were not susceptible to penicillin, with 19% intermediate and 18.8% resistant strains. High and intermediate resistance levels to cefotaxime were 4.9% and 10.9%, respectively. Decreased susceptibility to trimethoprim/sulfamethoxazole (TMS), erythromycin, chloramphenicol, and rifampin was found in 194 isolates (41.5%), 32 (6.8%), 13 (2.8%) and 3 (0.6%), respectively. No isolates resistant to vancomycin were detected. The most commonly combined resistance patterns were: penicillin/TMS (35.6%) and penicillin/TMS/cefotaxime (11.8%). This study highlights the increased rate of drug resistant S. pneumoniae during the last years, and the importance of antimicrobial resistance surveillance of adequate empirical therapy involving local and regional susceptibility patterns.

Specific IgA detection can be used for perinatal diagnosis of HIV in children under protocol ACTG 076

Detection of anti-HIV-1 IgA antibodies using a modified ELISA test for the early diagnosis of perinatally acquired HIV-1 infection in children treated with protocol ACTG 076 was evaluated. A total of 177 sera were obtained from 141 infants between 1 and 12 months of age (46 were treated and 95 were non-treated with protocol ACTG 076) and tested for HIV IgA antibodies by an ELISA test after removal of IgG with recombinant protein G. Infants were classified according to CDC's classification system after a follow-up until 20 months of age. Of the 46 treated children 22 turned out to be infected and in the group of 95 untreated children, 52 were infected. All 81 samples from uninfected children treated or untreated with protocol ACTG 076 were persistently IgA-negative. HIV IgA antibodies were detected in 14 of 25 plasma samples from infected children with treatment, and in 58 of 71 samples in infected children without treatment. Considering that the sensitivity of this test is lower in children younger than 6 months the population of children studied was divided into two groups; those under and those over 6 months of age. No significant differences were observed in the detection of IgA in treated or untreated children in both age groups. The overall specificity of the test was 100 per cent; sensitivity in children older than 6 months was 76.92 per cent in treated children and 93.10 per cent in untreated children. In spite of the small number of samples studied it could be demonstrated that treatment with zidovudine does not affect the detection of IgA antibodies. This is a simple and inexpensive method that could be used for diagnosis of treated and untreated children in developing countries.

Spinal cord stimulation: a possible therapeutic alternative for chronic mesenteric ischaemia

A 78-year-old male patient had chronic, unrelieved abdominal pain due to mesenteric ischaemia. Unsuccessful pharmacological approaches included oral morphine plus coadjuvants as well as a sympathetic celiac plexus block which gave pain relief that lasted for 72 h. In order to obtain long-lasting relief, a trial epidural stimulating electrode was implanted after obtaining informed consent and Ethical Committee approval. Complete analgesia was achieved during a trial period of 2 weeks. Thereafter, a spinal cord stimulator was implanted. At the time of writing, 11 months after implantation, the degree of analgesia is complete. We believe that spinal cord stimulation may represent an alternative approach in controlling pain due to mesenteric ischaemia.

CO2 laser surgery in osteomyelitis

OBJECTIVE

To prove that the thermal energy of CO2 lasers, when applied on the fistula, pyogenic sac, and septic bone in cases of osteomyelitis, creates an aseptic area, diminishes relapses, and promotes healing in those patients treated.

SUMMARY BACKGROUND DATA

CO2 laser surgery, whether used in a focused or unfocused manner, has been incorporated into surgical procedures because of its incisive, coagulating, and antiseptic properties. These forms and characteristics are especially useful in the treatment of chronic osteomyelitis.

METHODS

The authors recorded their experiences with 80 patients (10-75 years) with different types of chronic osteomyelitis. Classical surgical procedures were performed incorporating the CO2 laser beam.

RESULTS

Of the 80 patients, 45 healed with a single application combined with sequestrectomy implant removal, etc. Twenty-two patients needed up to three sessions to heal. Twelve patients did not heal, 1 asked for an amputation, and 3 were unavailable for follow-up procedures. We did not evaluate antibiotics prescribed, or cultures taken, due to the multiplicity of drugs used by chronic osteomyelitis patients with disease progression, and the various permutations and combinations of germs involved.

CONCLUSIONS

Although CO2 laser beam surgery cannot replace classic surgical procedures in osteomyelitis, it is an important adjunctive tool that helps enhance surgical effects and assists in the healing process.

[Evaluation of indirect immunofluorescence as a supplementary test for the diagnosis of HIV-1 infection]

In order to be used as an alternative or complementary test to confirm HIV-1 infection, the efficiency of indirect immunofluorescence assay (IFA) was compared with Western blot (WB) in 362 samples from persons with high and low risk behaviour. A panel of sera with 220 WB positive, 122 WB negative and 20 WB indeterminate sera were tested by an "in house" IFA. The sensitivity of IFA was found to be 98.63% and the specificity 98.36%. Therefore, IFA appeared to be an efficient alternative method to WB, since the cost of testing by IFA is less than 10% of WB testing. We observed a direct relationship between WB protein reactivity and IFA results. In 15 samples with coincident indeterminate results for WB and IFA, antibody reactivity to p24 and gp160 presented the highest frequency. On the other hand, antibodies to viral glycoproteins were always present in IFA weak positive samples, showing their high predictive value.

Different integrated and unintegrated HIV-1 DNA after superinfection and cell to cell transmission

Efficient superinfection of H9HTLVIIIB cell line (persistently infected with HIVHXB2 strain) with HIVMN strain is reported. The superinfecting viral DNA was found in the chromosomic and extrachromosomic fractions at early stages, but at 48 hours post superinfection, it remained mainly unintegrated. Interestingly, superinfected cells only produced HIVHXB2 in the supernatant and no increase of viral yield of this persistent virus was observed. Remarkably, virions of both strains. HIVHXB2 and HIVMN, were recovered after cocultivating superinfected cells with MT2 cell line. In the extrachromosomic fractions of seven different superinfected subclons of H9HTLVIIIB, viral DNA of the superinfecting HIVMN strain predominated while in the chromosomic fraction, the proportion of superinfecting viral DNA differed. The study of the presence of different integrated and unintegrated genomes in a single cell could be crucial in the understanding of HIV biology.

Active surveillance for Vibrio cholerae O1 and vibriophages in sewage water as a potential tool to predict cholera outbreaks

The 1991 Peruvian cholera epidemic has thus far been responsible for 600,000 cholera cases in Peru. In an attempt to design a cholera surveillance program in the capital city of Lima, weekly sewage samples were collected between August 1993 and May 1996 and examined for the presence of Vibrio cholerae O1 bacteria and V. cholerae O1 bacteriophages (i.e., vibriophages). During the 144 weeks of surveillance, 6,323 cases of clinically defined cholera were recorded in Lima. We arbitrarily defined an outbreak as five or more reported cases of cholera in a week. The odds of having an outbreak were 7.6 times greater when V. cholerae O1 was present in sewage water during the four previous weeks compared with when it was not (P < 0.001). Furthermore, the odds of having an outbreak increased as the number of V. cholerae O1 isolations during the previous 4 weeks increased (P < 0.001). The odds of having an outbreak were 2.4 times greater when vibriophages were present in sewage water during the four previous weeks compared with when they were not, but this increase was not statistically significant (P = 0.15). The odds of having an outbreak increased as the number of vibriophage isolations during the previous 4 weeks increased (P < 0.05). The signaling of a potential cholera outbreak 1 month in advance may be a valuable tool for implementation of preventive measures. In Peru, active surveillance for V. cholerae O1 and possibly vibriophages in sewage water appears to be a feasible and effective means of predicting and outbreak of cholera.