Ivermectin reduces in vivo coronavirus infection in a mouse experimental model

The objective of this study was to test the effectiveness of ivermectin for the treatment of mouse hepatitis virus (MHV), a type 2 family RNA coronavirus similar to SARS-CoV-2. Female BALB/cJ mice were infected with 6,000 PFU of MHV-A59 (group infected, n = 20) or infected and then immediately treated with a single dose of 500 µg/kg ivermectin (group infected + IVM, n = 20) or were not infected and treated with PBS (control group, n = 16). Five days after infection/treatment, the mice were euthanized and the tissues were sampled to assess their general health status and infection levels. Overall, the results demonstrated that viral infection induced typical MHV-caused disease, with the livers showing severe hepatocellular necrosis surrounded by a severe lymphoplasmacytic inflammatory infiltration associated with a high hepatic viral load (52,158 AU), while mice treated with ivermectin showed a better health status with a lower viral load (23,192 AU; p < 0.05), with only a few having histopathological liver damage (p < 0.05). No significant differences were found between the group infected + IVM and control group mice (P = NS). Furthermore, serum transaminase levels (aspartate aminotransferase and alanine aminotransferase) were significantly lower in the treated mice than in the infected animals. In conclusion, ivermectin diminished the MHV viral load and disease in the mice, being a useful model for further understanding this therapy against coronavirus diseases.

Development, behaviour and sensory processing in Marshall-Smith syndrome and Malan syndrome: phenotype comparison in two related syndromes

BACKGROUND

Ultrarare Marshall-Smith and Malan syndromes, caused by changes of the gene nuclear factor I X (NFIX), are characterised by intellectual disability (ID) and behavioural problems, although questions remain. Here, development and behaviour are studied and compared in a cross-sectional study, and results are presented with genetic findings.

METHODS

Behavioural phenotypes are compared of eight individuals with Marshall-Smith syndrome (three male individuals) and seven with Malan syndrome (four male individuals). Long-term follow-up assessment of cognition and adaptive behaviour was possible in three individuals with Marshall-Smith syndrome.

RESULTS

Marshall-Smith syndrome individuals have more severe ID, less adaptive behaviour, more impaired speech and less reciprocal interaction compared with individuals with Malan syndrome. Sensory processing difficulties occur in both syndromes. Follow-up measurement of cognition and adaptive behaviour in Marshall-Smith syndrome shows different individual learning curves over time.

CONCLUSIONS

Results show significant between and within syndrome variability. Different NFIX variants underlie distinct clinical phenotypes leading to separate entities. Cognitive, adaptive and sensory impairments are common in both syndromes and increase the risk of challenging behaviour. This study highlights the value of considering behaviour within developmental and environmental context. To improve quality of life, adaptations to environment and treatment are suggested to create a better person-environment fit.

Role of inflammasome activation in tumor immunity triggered by immune checkpoint blockers

Immune checkpoint blockers improve the overall survival of a limited number of patients among different cancers. Identifying pathways that influence the immunological and clinical response to treatment is critical to improve the therapeutic efficacy and predict clinical responses. Recently, a key role has been assigned to innate immune mechanisms in checkpoint blockade-driven anti-tumor responses. However, inflammatory pathways can both improve and impair anti-tumor immunity. In this review, we discuss how different inflammatory pathways, particularly inflammasome activation, can influence the clinical outcome of immune checkpoint blockers. Inflammasome activation may reinforce anti-tumor immunity by boosting CD8⁺ T cell priming as well as by enhancing T helper type 17 (Th17) responses. In particular, we focus on the modulation of the cation channel transmembrane protein 176B (TMEM176B) and the ectonucleotidase CD39 as potential targets to unleash inflammasome activation leading to reinforced anti-tumor immunity and improved efficacy of immune checkpoint blockers. Future studies should be aimed at investigating the mechanisms and cell subsets involved in inflammasome-driven anti-tumor responses.

Benznidazole treatment reduces the induction of indoleamine 2,3-dioxygenase (IDO) enzymatic activity in Chagas disease symptomatic patients

The enzyme indoleamine 2,3-dioxigenase (IDO) is critical for the regulation of immune responses in pro-tolerogenic antigen-presenting cell. To address the profile of immune responses associated with Chagas disease, we measured IDO activity of peripheral blood mononuclear cells from 168 chronic patients and 13 healthy donors. We found that IDO activity was increased in patients with Chagas disease when compared with controls. Moreover, the IDO activity of patients with Chagas disease in the symptomatic chronic phase, involving cardiac or digestive alterations, was higher than that detected in asymptomatic patients and correlated with the severity of the symptoms. Furthermore, benznidazole treatment induced a long-lasting decrease in IDO activity in symptomatic patients, reaching levels comparable with those of healthy donors. These results suggest that a pro-tolerogenic state is associated with the severity of Chagas disease and that benznidazole treatment is a valuable tool for breaking the parasite-driven immune tolerance in the symptomatic chronic phase of Chagas disease.

Autologous dendritic cells prolong allograft survival through Tmem176b-dependent antigen cross-presentation

The administration of autologous (recipient-derived) tolerogenic dendritic cells (ATDCs) is under clinical evaluation. However, the molecular mechanisms by which these cells prolong graft survival in a donor-specific manner is unknown. Here, we tested mouse ATDCs for their therapeutic potential in a skin transplantation model. ATDC injection in combination with anti-CD3 treatment induced the accumulation of CD8(+) CD11c(+) T cells and significantly prolonged allograft survival. TMEM176B is an intracellular protein expressed in ATDCs and initially identified in allograft tolerance. We show that Tmem176b(-/-) ATDCs completely failed to trigger both phenomena but recovered their effect when loaded with donor peptides before injection. These results strongly suggested that ATDCs require TMEM176B to cross-present antigens in a tolerogenic fashion. In agreement with this, Tmem176b(-/-) ATDCs specifically failed to cross-present male antigens or ovalbumin to CD8(+) T cells. Finally, we observed that a Tmem176b-dependent cation current controls phagosomal pH, a critical parameter in cross-presentation. Thus, ATDCs require TMEM176B to cross-present donor antigens to induce donor-specific CD8(+) CD11c(+) T cells with regulatory properties and prolong graft survival.

Evidence for widespread Leishmania infantum infection among wild carnivores in L. infantum periendemic northern Spain

Leishmania spp. infection was investigated in tissue samples of wild carnivores from the Spanish Basque Country (BC), by PCR and DNA sequencing. The region is at the northern periphery of Leishmania infantum endemic Iberian Peninsula and infection in the dog (reservoir) or other species has not been previously reported. Leishmania kinetoplast DNA was detected by real-time PCR (rtPCR) in 28% (44/156) of animals. Specifically, in 26% of Eurasian badgers (n=53), 29% of foxes (n=48), 29% of stone martens (n=21) and in 25-50% of less numerous species including genets, wild cats, pole cats, European mink and weasels. Infected animals particularly badgers, were most prevalent in the southernmost province of the BC (Araba) in areas dominated by arable land. Subsequent amplification and sequencing of a fragment of the rRNA internal transcribed spacer 2 (ITS2) from a subset of rtPCR positives samples confirmed the species as L. infantum, showing a high sequence homogeneity with ITS2 sequences of L. infantum from dogs and humans from southern Spain. In summary, this study reports for the first time L. infantum infection in wild carnivores from the BC including in stone martens, pole cats and minks in which infection has not been previously described. It supports the need to study infection in dogs and people in this region and is an example of the value of infection surveillance in wildlife to assess potential risks in the domestic environment and their role in spreading infections in non-endemic areas.

Fatal visceral leishmaniasis, with massive bone-marrow infection, in an immunosuppressed but HIV-negative Spanish patient, after the initiation of treatment with meglumine antimoniate

Although visceral leishmaniasis is often fatal in the developing world, Leishmania-attributable deaths in Europe are relatively rare and nowadays almost always linked to HIV infection. In Spain, however, a HIV-negative man with a history of chronic obstructive pulmonary disease and prednisone treatment was recently hospitalized because of hypotension and asthenia. Although the patient was afebrile, a bone-marrow aspirate, collected after thrombo- and leuco-cytopenia had been observed, was found to contain huge numbers of amastigotes. A course of antileishmanial treatment with meglumine antimoniate was initiated but the patient went into refractory shock and died within 6 h. The significance of this case, in terms of the routine investigation and treatment of immunosuppressed patients who may have leishmaniasis, is discussed.

Cell therapy with autologous tolerogenic dendritic cells induces allograft tolerance through interferon-gamma and epstein-barr virus-induced gene 3

Innovative therapeutic strategies are needed to diminish the impact of harmful immunosuppression in transplantation. Dendritic cell (DC)-based therapy is a promising approach for induction of antigen-specific tolerance. Using a heart allograft model in rats, we analyzed the immunoregulatory mechanisms by which injection of autologous tolerogenic DCs (ATDCs) plus suboptimal immunosuppression promotes indefinite graft survival. Surprisingly, we determined that Interferon-gamma (IFNG), a cytokine expected to be propathogenic, was threefold increased in the spleen of tolerant rats. Importantly, its blockade led to allograft rejection [Mean Survival Time (MST) = 25.6 ± 4 days], showing that IFNG plays a critical role in immunoregulatory mechanisms triggered by ATDCs. IFNG was expressed by TCRαβ(+) CD3(+) CD4(-) CD8(-) NKRP1(-) cells (double negative T cells, DNT), which accumulated in the spleen of tolerant rats. Interestingly, ATDCs specifically induced IFNG production by DNT cells. ATDCs expressed the cytokinic chain Epstein-Barr virus-induced gene 3 (EBI3), an IL-12 family member. EBI3 blockade or knock-down through siRNA completely abolished IFNG expression in DNT cells. Finally, EBI3 blockade in vivo led to allograft rejection (MST = 36.8 ± 19.7 days), demonstrating for the first time a role for EBI3 in transplantation tolerance. Taken together our results have important implications in the rationalization of DC-based therapy in transplantation as well as in the patient immunomonitoring follow-up.

Side effects of benznidazole treatment in a cohort of patients with Chagas disease in non-endemic country

Chagas disease is a disease endemic in Latin America, caused by the parasite Trypanosoma cruzi. Benznidazole is the most commonly used drug for the etiological treatment of the disease although its effectiveness varies according to the phase of the same and toxic side effects are frequent. This prospective study describes the side effects of benznidazole treatment of a cohort of 373 chronic patients. Of these 40.2% presented adverse reactions. The most frequent side effect were dermatological reactions 32.4% (121 of 373) followed by digestive intolerance 9.1% (34 of 373). Surprisingly, three cases of migratory arthritis were observed. Patients treated with benznidazole must be followed up so that the long term incidence of side effects can be studied.

Cryptic Leishmaniosis by Leishmania infantum, a feature of canines only? A study of natural infection in wild rabbits, humans and dogs in southeastern Spain

An epidemiological study was carried out to investigate asymptomatic Leishmania infantum infection by PCR and ELISA in wild rabbits, humans and domestic dogs in southeastern Spain. Seroprevalence was 0% (0/36) in rabbits, 2% (13/657) in humans and 7% (14/208) in dogs. The prevalence of PCR-positives was 0.6% (1/162) in rabbits tested in a wide range of tissue samples, 2% (8/392) in humans analysed in blood samples and 10% (20/193) and 67% (29/43) in dogs analysed in blood and lymphoid tissue samples, respectively. Results suggest that wild rabbits have a very low risk of becoming chronically infected with L. infantum, and provide further evidence that cryptic L. infantum infection is widespread in the domestic dog population and is also present in a comparatively smaller proportion of healthy humans. The epidemiological and clinical implications of these findings are discussed.

Geographical variation and factors associated to seroprevalence of canine leishmaniosis in an endemic Mediterranean area

This article retrospectively analyses the spatial distribution and dog- and environmental-level risk factors associated to Leishmania infantum seroprevalence among 807 asymptomatic dogs in the Municipality of Crevillente in Alicante in southeast Spain in 1999. They represented 60% of the dogs in this 103 km2 area, with a human census of 27 034 people and 90% lived in Crevillente town. The estimated seroprevalence (95% confidence interval) in 714 dogs > or =1-year old was 22% (19-25) however; it was 12% (8-15) in town dogs and 0-100% in other administrative zones. High-medium seroprevalence zone clustered along a northeast-southwest fringe and around the town. They comprised the highest and driest inhabited part of the municipality, where farmland was interspersed by residential detached houses, whilst null-low seroprevalence zones included larger farmland extensions and two small rural villages. Predominant vegetation and ground soil type were bush, non-irrigated fruit trees and conglomerate crust and sandstone in medium-high seroprevalence zones and irrigated grassland and fruit trees and colluvial deposits in null-low seroprevalence zones. Random effects logistic regression indicated that the prevalence of infection with L. infantum was higher for dogs sharing residence with infected dogs, increased until 5-6 years old and with body weight and was associated to increasing conglomerate crust and low surface water in the dog's zone of residence. The study confirms that L. infantum infection is endemic in this part of Spain and shows that prevalence can vary significantly within a small area depending on specific demographic and environmental factors conditioning the habitat of the local L. infantum vector, Phlebotomus perniciosus. It suggests similar low-scale variability is present in other geographically variable endemic areas and should be investigated to design Leishmaniosis risk maps and cost-effective, evidence-based, targeted control interventions.

Evaluation of three immunochromatographic assays for detection of Legionella pneumophila serogroup 1 antigen in urine samples

The Uni-Gold, the SAS and the Binax NOW immunochromatographic test (ICT) urinary antigen assays for the qualitative detection of Legionella pneumophila serogroup 1 were compared using 39 unfrozen and nonconcentrated urine samples from patients with Legionnaires disease (LD). The Uni-Gold antigen test detected the urinary antigen in 41% (16/39), the SAS antigen test in 61.5% (24/39), and the Binax NOW antigen test in 74.3% (29/39). The Binax NOW ICT assay showed the best results when detecting L. pneumophila urinary antigen.

Questionnaire survey on Canine Leishmaniosis in southeastern Spain

A veterinary practitioner's questionnaire survey on Canine Leishmaniosis (CanL) was carried out in southeast Spain to provide information on disease incidence, diagnosis and recommended preventive measures. A third of 101 responding veterinarians reported seeing more than 20 CanL cases during the previous year and clinical signs considered frequent or very frequent included weight loss, areas of exfoliative dermatitis, lymphadenomegaly, kidney dysfunction, onychogryphosis, cutaneous ulcers, anaemia, asthenia and apathy. Almost a third of veterinarians reported diagnosing CanL solely on the basis of lack of response to treatment for other chronic illnesses. The frequency of individual signs did not always reflect their diagnostic value. The majority of veterinarians, considered lymphadenomegaly, exfoliative dermatitis, onychogryphosis, weight loss and epistaxis to be the best disease indicators. However, up to 93% of veterinarians reported using laboratory tests to confirm infection, including indirect (biochemical and antibody assays) and direct (PCR and microscopy) methods. Among recommended measures to prevent CanL, insecticide impregnated collars and topical spot-on capsules were prescribed by 92% and 74% of respondents; however, at least 11% of veterinarians believed existing CanL preventive measures were ineffective. Multivariable statistical analysis indicated that seeing more than 20 CanL cases during the previous year was independently associated with being located in Alicante province, having a rural clientele and recognising that dogs with no other sign but a lack of response to other chronic disease treatments may be infected with CanL. There was a weak association between CanL incidence and rainfall in the months prior to typical sandfly peak abundance.

Sensitivity of urinary antigen test in relation to clinical severity in a large outbreak of Legionella pneumonia in Spain

Presented here are the results of Legionella urinary antigen testing correlated with patient characteristics and severity of pneumonia (Fine score) in 295 patients diagnosed with Legionella pneumonia in connection with a large outbreak in Murcia, Spain. Overall, the sensitivity of the urinary antigen test was 47.7% (141/295). A statistically significant association was found between the clinical severity of pneumonia and test sensitivity; 85.7% for patients with severe pneumonia versus 37.9% for patients with mild pneumonia (risk ratio, 2.3). Variables significantly associated with test positivity in multivariate analysis were as follows: pre-existing pulmonary disease, body temperature >40 degrees C, leukocytosis and multilobar infiltrates. Patients with mild pneumonia may go undiagnosed if the urinary antigen test is used alone.

LD1 amplifications in Leishmania

The genome of Leishmania is quite plastic. Chromosomal rearrangements and DNA amplifications are common events in all the species of the genus. Gene amplification occurs both as a mechanism of drug resistance and in the absence of drug pressure. The best known spontaneous amplification in Leishmania is the so-called LD1 family of amplicons. In the past few years there have been great advances in our knowledge of LD1 elements; here, Manuel Segovia and Ginés Ortiz review all the available data.

[Nitric oxide in malignant astrocytes]

INTRODUCTION

One of the different molecules involved in the development of astrocytomas is nitric oxide (NO), a gaseous radical that, depending on the cell type and the experimental paradigm selected in the pathology, can play either a cytotoxic or a cytoprotective role.

DEVELOPMENT

During the development of an astrocytoma NO acts as a tumouricidal agent, although it can also alter vascular reactivity and lead to neovascularisation, thereby contributing to the invasive capacity (aggressiveness) of the tumour. One of the mechanisms of tumoural progression consists in the protein inactivation resulting from the NO nitration of tyrosine from proteins coded for by tumour-suppressing genes, such as p53. Furthermore, in malignant astrocytes, nitrosoglutathione, a natural NO-donor, has been seen to play a role in the chemoresistance displayed against nitrosourea derivatives. The NO excreted by irradiated astrocytoma cells also appears to be involved in the resistance to the radiotherapy shown by non-irradiated cells.

CONCLUSIONS

The molecular mechanisms behind the complex and paradoxical activity of NO in glioblastoma multiforme have still not been fully explained and its implications in vivo are even further from being completely understood.

[Antimicrobial susceptibility of Pseudomonas aeruginosa clinical isolates in Murcia, Spain]

The source and antimicrobial susceptibility of 1293 clinical isolates of Pseudomonas aeruginosa obtained from 1996 to 1999 were studied. Urine was the most common source for outpatient isolates (61.2%), while for hospitalized patients respiratory samples were the most frequent (40.2%). The most active antimicrobials with resistance rates <=10% were ceftazidime, imipenem, tobramycin and amikacin. By contrast, aztreonam, ciprofloxacin and gentamicin showed resistance levels >10%. The percentages of resistance to ceftazidime, aztreonam and imipenem in isolates from inpatients and from patients in the intensive care unit were significantly higher than those in isolates from outpatients and other clinical departments. Comparison of susceptibility data from 1996 to 1999 showed a significant increase in the resistance rate for all of the antibiotics studied but imipenem.

Use of direct latex agglutination testing of selective broth in the detection of group B strepptococcal carriage in pregnant women

Direct latex agglutination testing of selective broth medium for the detection of group B streptococci was evaluated. Results were compared with those obtained by the recommended subculture method. Among the 551 vaginal-rectal specimens tested, 101 (18.3%) were positive by the subculture method. Of these subcultures, latex agglutination testing detected 99 (98%) positive specimens. Agglutination testing of selective broth is a sensitive method which offers the advantage of saving 24 h in the turnaround time for detection of group B streptococci in pregnant women.

Light regulation of cyclic-AMP levels in the red macroalga Porphyra leucosticta

Total cyclic-3'-5'-adenosine monophosphate (cAMP) levels were measured in the gametophyte of the red macroalga Porphyra leucosticta under different light conditions in order to study its regulation by phytochrome or photosynthesis. cAMP levels were relatively low when samples were incubated in darkness, or exposed to red or far-red light. Irradiation with red+far-red light induced a moderate increase in cAMP levels, while white light induced a pronounced increase in cAMP levels. When incubated under increasing white light irradiance, cAMP levels closely followed the increase in photosynthetic oxygen evolution rate, suggesting a direct relationship between photosynthesis and cAMP accumulation. cAMP levels were not dependent on cellular ATP concentration, as inhibitors of ATP synthesis did not significantly affect cAMP levels in light. We conclude that cAMP depends on photosynthetic activity regardless of ATP synthesis and concentration or phytochrome activity.

[Occupational exposures to blood-borne pathogens in health care workers]

OBJECTIVE

To determine the rate of occupational exposures to blood-borne pathogens in different occupations of health care workers. To analyze the characteristics and outcome of the occupational exposure.

MATERIAL AND METHODS

We have evaluate occupational exposures to blood-borne pathogens reported by health care workers during 1996-1999. The following data were collected: characteristics of the workers, type of occupational exposure, immunity status of the exposed worker, infectivity of the source patient and follow up serologic testing of the worker.

RESULTS

A total of 407 occupational exposures were reported. The highest rate of occupational exposure was found among nurses (61.6%). Needlestick accident was the most often occupational exposure reported (84.5%). Mucosal exposures with accidental splashes were reported in 15.2% of cases. In 14.5% of these accidents workers were at risk for occupational transmission of blood-borne pathogens. Among the different occupations of health care workers, the rate of exposures with a source infected patient was higher in medical staffs (28.3%) than nurses (13.9%) The rate of exposures with a source infected patient was higher in accidental splashes than in percutaneous exposures (33.8% vs 13.3%), besides in none of the accidental splashes, employees had used appropriate barrier precautions. There were no cases of transmission of occupational blood-borne infections.

CONCLUSIONS

Although nurses are the health care workers with highest rates of occupational exposures, medical staffs are the most often occupationally exposed to a source infected patient. Universal barrier precautions are no appropriately used in most of the occupational accidents, specially in those involving mucosal exposures.

[Comparative study of 3 tests for susceptibility of Mycobacterium tuberculosis to first-line antituberculous drugs]

Treatment of tuberculosis requires a multidrug regimen for a prolonged period of time (6-12 months), which leads to a high level of noncompliance with therapy. This lack of compliance has led to an increase in drug-resistant strains of Mycobacterium tuberculosis. Rapid drug susceptibility tests are needed to assess effective chemotherapy regimens. In the present study, the reliability of ESP Myco System II(R) and E-test(R) for determining the susceptibility of 82 clinical isolates of M. tuberculosis to rifampin, isoniazid, streptomycin and ethambutol was evaluated by comparing results to those of the multiple proportion method as a reference. ESP Myco System II(R) is a nonradioactive, totally automated, continuously monitored system designed to detect grown mycobacteria. E-test(R) is a well-described method of susceptibility testing which provides data on minimal inhibitory concentration. The susceptibility results of both methods were available within 9 days, while those of the proportion method required 28 days. Levels of agreement between ESP Myco System II(R) and the proportion method for the clinical isolates analyzed were 100% for rifampin, isoniazid and ethambutol. Only one discrepancy was found for streptomycin. For the E-test(R), the results were less favorable. ESP Myco System II(R) was shown to be a rapid and reliable method for testing susceptibility of M. tuberculosis isolates. Nevertheless, E-test(R) provided low specificity for streptomycin and ethambutol. Further studies to test the reliability of the E-test(R) are necessary.

Receiver operating characteristics curve analysis of factors predictive of nonresponse to interferon therapy in patients with chronic hepatitis C

OBJECTIVES

1) to identify pretreatment variables predictive of nonresponse to interferon-alpha (IFN-alpha) in patients with chronic hepatitis C, and 2) to establish a prognostic index in these groups using receiver operating characteristics curve analysis.

METHODS

132 patients were treated with IFN-alpha at a dose of 3 megaunits three times a week for 3-12 months. The response was compared in patients with a complete response vs nonresponders, and patients with a sustained response vs nonresponders plus relapsers. Factors predictive of response were identified by analyzing clinical, biochemical, virological and histological variables.

RESULTS

The sustained response rate was 12.8% at 24 months of follow-up. The pretreatment characteristics with a predictive value (PV) according to area under the ROC curve and 95% confidence interval > 0.5 were age, known duration of infection, history of transfusion, GGT, serum ferritin levels, viral load, genotype, and grade and stage of the histological lesion. The positive PV (the probability of predicting absence of response when the variable is present) was notably greater than the negative PV (mean: 94.9% vs 24.8%, respectively). In addition, when 4 and 6 variables were present, the positive PV was 100% and sensitivity was 60.2% and 22.1%, respectively. The predictive variables independently associated with an absence of response were genotypes 1, 4 and 5, GGT > 24 IU/l and grade of the histological lesion > 6.

CONCLUSIONS

It was possible to predict the absence of both primary and posttreatment response with an acceptable degree of reliability.

Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia

Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 10(9). sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 microM), propidium iodide (2.4 mM), and rhodamine 123 (0.13 microM) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 degrees C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

[ROC curve analysis of factors predictive of non-response to interferon treatment in patients with chronic hepatitis C, genotype 1]

The objectives of this study included: 1) to identify pretreatment variables predictive of absence of response in 107 patients with chronic hepatitis C, genotype 1, treated with interferon-a (IFN-a) at a dose of 3 MU three times weekly for 3-12 months and classified into two groups: group A, nonresponders vs. patients with a complete response, and group B, nonresponding and relapsing patients vs. patients with a sustained response; and 2) to establish a prognostic index using ROC curve analysis. The rate of sustained response was 6. 5&#37; at the 24-month follow-up. The pretreatment characteristics with predictive value using ROC curves were as follows: in group A, age, GGT, serum ferritin, viral load, and grade and stage of the histological lesion; and in group B, known duration of infection, GPT, GGT, serum ferritin, viral load, and grade and stage of the histological lesion. In both group A and group B the positive predictive value (the probability of predicting an absence of response when the variable is present) was greater than the negative predictive value (mean: 84.3% vs. 41.1%, 99% vs. 16.5%, respectively). In group A, based on the prognostic index, the positive predictive value when three variables were present was 96&#37; and the sensitivity was 63.5&#37;, with the test being unequivocal in 6.5&#37;, whereas when four or five variables were present, the positive predictive value was 97&#37; and 100&#37; and the sensitivity was 40.5&#37; and 18&#37;, respectively. In group B, the positive predictive value when two variables were present was 100&#37; and the sensitivity was 87&#37;, whereas when three, four, five and six variables were present the sensitivity was between 73&#37; and 28&#37;. In group A, age, GGT and ferritin were the predictive variables independently associated with an absence of response, with a relative risk of 6.5, 4.8 and 3.1, respectively, whereas in group B we did not find variables independently associated with an absence of response. It was concluded that in patients with genotype 1, it is possible to predict the absence of response to IFN therapy with a high degree of reliability.

Detection of mycoloylglycerol by thin-layer chromatography as a tool for the rapid inclusion of corynebacteria of clinical origin in the genus Corynebacterium

A chemotaxonomic study of some corynebacteria isolated from clinical samples revealed characteristic thin-layer chromatographic patterns for meso-diaminopimelic acid containing species included in the genera Corynebacterium, Dermabacter and Brevibacterium. Notably, a specific compound was consistently detected in mycolic acid containing species of the genus Corynebacterium. This compound was composed by glycerol and mycolic acids and structural analyses carried out by fast atom bombardment mass spectrometry in C. minutissimum confirmed its identification as mycoloylglycerol. The chain length of mycoloyl groups in this molecule ranged from 28 to 34 carbon atoms, being mono-, di- or triunsaturated. Detection of mycoloylglycerol by thin-layer chromatography may be thus useful for the rapid inclusion of a great variety of corynebacteria of clinical origin in the genus Corynebacterium in laboratories employing chromatographic techniques as an adjunct for the identification of these microorganisms.

Appearance of resistance to meropenem during the treatment of a patient with meningitis by Acinetobacter

A case is reported of a patient who developed Acinetobacter meningitis after an external ventricular drainage system had been fitted for control of intracranial pressure. During the process, nine strains of Acinetobacter isolated from her cerebrospinal fluid were indistinguishable by analysis of total genomic DNA by pulse-field gel electrophoresis. The first eight strains were sensitive to meropenem and imipenem (MICs < 1 g/l). The MIC of the last one, which had been recovered after 32 days during two courses of treatment with meropenem, increased to > 32 g/l for meropenem, while with imipenem the increase was minimal (MIC = 1.5 g/l). The microorganism persisted in the central nervous system despite the administration of different antimicrobials, including intraventricular aminoglycosides and six changes in the external ventricular system. The patient died 68 days after admission to the intensive care unit from bilateral cerebral ischemic lesions, intraventricular hemorrhage and cerebral edema with endocraneal hypertension, the Acinetobacter ventriculitis also contributing to this state.

Assessment of multiple coagulase-negative staphylococci isolated in blood cultures using pulsed-field gel electrophoresis

One of the criteria used to determine the clinical importance of coagulase-negative staphylococci (CNS) is the isolation of the bacteria from sequential blood cultures. Sequential isolates of CNS obtained from five immunocompromised patients over three months were genetically characterized by pulsed-field gel electrophoresis (PFGE). This typing method was compared to two first-line typing methods: determination of the species and of antibiotic susceptibility. In four patients the initial clinical evaluation changed because of the PFGE results several episodes of bacteremia would have been wrongly assessed if only the biotype and the antibiotype had been determined. Pulsed-field gel electrophoresis should therefore be used for CNS strains from immunocompromised patients or those suffering from chronic diseases with non-concordant biotype and anti-biotype.

Acyl phosphatidylglycerol: a major phospholipid of Corynebacterium amycolatum

The type strain and several clinical isolates of Corynebacterium amycolatum were examined for lipid composition as a chemotaxonomic character for routine identification. The phospholipid profile was composed of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides, together with various unidentified compounds. One of them, accounting for 20-29% of total phospholipids, was purified and characterized as acyl phosphatidylglycerol by chromatographic and spectrometric techniques. The acyl substituents on the phosphatidyl moiety were characterized as tetradecanoyl, pentadecanoyl, hexadecenoyl, hexadecanoyl, heptadecenoyl, heptadecanoyl, octadecenoyl (the major one), and octadecanoyl. The acyl group on the polar head (glycerol) was only octadecenoyl. Phospholipid analysis by thin-layer chromatography of a collection of Corynebacterium strains proved that this compound is widely distributed, although it only represents a minor (2-9%) component among mycolic acid-containing species. Acyl phosphatidylglycerol can be considered as a useful chemical marker for the identification of C. amycolatum in addition to the absence of mycolic acids.

Characterisation of the novel junctions of two minichromosomes of Leishmania major

The minichromosomes M210 and M230 of Leishmania major are linear amplicons which have an inverted repeat structure. We report here the molecular cloning of the megabasic chromosome region where M210 and M230 recombination points are located. The analysis of this chromosomal region revealed a 374 bp fragment directly repeated 3 times, which was also repeated elsewhere in the genome. DNA fragments containing the novel junctions of the minichromosomes M210 and M230 have been likewise cloned. The nucleotide sequence of these fragments was determined and compared with their corresponding DNAs in the source chromosome. It revealed that M210 contains a central 226 bp non-repeated fragment, whereas the central fragment of M230 was 5 kb long. A 9 bp sequence which was repeated in inverted orientation around the recombination points of M230 was found. M210 showed instead an A + T rich DNA which could be implicated in its generation.

Differentiation between Mycobacterium tuberculosis and Mycobacterium bovis by a multiplex-polymerase chain reaction

A multiplex-polymerase chain reaction (PCR) assay, based on one-step amplification and detection of three different mycobacterial genomic fragments, was designed for differentiation between Mycobacterium bovis and Mycobacterium tuberculosis. The oligonucleotide primers were chosen from the groEL gene, present in the genus Mycobacterium sp., from the IS6110 insertion sequence, present in Myco. tuberculosis complex and from the mtp40 gene, identified as a specific-species Myco. tuberculosis genomic fragment. This amplification method allowed the detection of two fragments of 576 and 317 base pairs in Myco. bovis and three fragments of 576, 396 and 317 base pairs in Myco. tuberculosis strains, including atypical strains of Myco. tuberculosis where the copy number of the IS6110 element is low. The multiplex-PCR assay described may be a very useful tool for the rapid and specific differentiation of these related mycobacteria and easy to use in medical and veterinary microbiology laboratories.

[Use of alcoholism psychiatric services during an 18-month follow-up of alcoholic men]

BACKGROUND

The paper assesses the use of public psychiatric services by alcoholic patients for a period of 18 months, and looks for possible sociodemographic and clinical variables associated with higher use of services.

MATERIAL AND METHODS

A prospective study of a cohort of male alcoholics (n = 137) from Alava (Spain). Information was gathered at the beginning of a treatment episode using a structured interview on sociodemographic and clinical variables, including Michigan Alcoholism Screening Test (MAST), and General Health Questionnaire (GHQ-60). At 18 month follow-up, clinical records were used to examine psychiatric inpatient and outpatient use in Alava (Spain). A service use score was set up to measure global use of services.

RESULTS

Eighty-three percent of alcoholics used outpatient services at least once, 48% attended the day-care service at least once, and 24% were admitted in a psychiatric unit at least once, during 18 month follow-up. Twenty percent of patients used 80% of services. The logistic regression models point to the age, civil status, alcohol consumption amount and previous history of alcoholic treatments as the main predictors for heavy use of psychiatric services.

CONCLUSIONS

A small percentage of alcoholics in treatment use the main part of psychiatric resources.

Evaluation of mtp40 genomic fragment amplification for specific detection of Mycobacterium tuberculosis in clinical specimens

A PCR assay based on the species-specific mtp40 genomic fragment was developed for the specific detection and identification of Mycobacterium tuberculosis in different uncultured clinical specimens. The aim of the study was to evaluate the clinical applicability of this target DNA in comparison with those of conventional microbiological methods and to compare the results obtained with those obtained after amplification with the IS6110 repetitive element. Discrepant results were interpreted in conjunction with the patients' clinical data, medical histories, and response to therapy. A total of 172 specimens from 162 patients with respiratory symptoms were tested, 101 specimens were obtained from 92 patients clinically suspected of having tuberculosis, and 71 specimens were obtained from 70 patients without known mycobacterial infection. The results of our study suggest that PCR amplification with the mtp40 genomic fragment provides a highly sensitive and specific technique for the detection of M. tuberculosis strains in clinical samples. It allows for the differentiation between M. tuberculosis and other related mycobacteria, including M. bovis, and is more specific than the IS6110 target. For these and other reasons, we propose that the mtp40 assay is a possible alternative for the specific direct detection of M. tuberculosis in clinical laboratories.

Evidence from genotypic and phenotypic markers that an attenuated line outgrows a virulent one in a mixed population of Leishmania major promastigotes cultured in vitro

Two cloned lines of Leishmania major promastigotes, one attenuated (CO1H) and one virulent (CO1R), differing in molecular karyotype and expression of the major surface glycoprotein (gp63), were mixed to produce two heterogeneous populations: MP-1 (100 CO1R promastigotes/CO1H promastigote); and MP-2 (10,000 CO1R promastigotes/CO1H promastigote). The mixed populations were cultured for 1 month in vitro in HO-MEM medium and sub-samples taken on days 4 and 30 were subjected to electrophoresis so that the molecular karyotypes and gp63-expression characteristics of the promastigote populations could be determined. In spite of the initial predominance of the virulent CO1R, the attenuated CO1H always outgrew it. The patterns of growth of pure cultures of CO1H or CO1R did not fully explain this observation. When grown alone, CO1H acidified the culture medium much more and much faster than CO1R, low pH values eventually inhibiting multiplication. Decreasing the medium's initial glucose concentration or increasing its initial pH prolonged the growth phase of CO1H, probably by slowing its acidification of the medium to inhibitory values. It is possible that, in mixed populations, the CO1R promastigotes help to buffer the medium, permitting faster and longer multiplication of the CO1H promastigotes than occurs when they are cultured alone. CO1H promastigotes may also inhibit CO1R multiplication; CO1H promastigotes in mid-logarithmic phase entered stationary phase within a day of being transferred into cell-free supernatants from 3-day-old CO1R cultures.

The management information system and change processes in health systems

This report describes a management information system (MIS) designed by PAHO's Health Systems and Services Division in collaboration with technical experts from a number of different countries. This MIS, a methodology currently used at the institutional or national level in more than 21 countries of the Americas, is a strategic and practical instrument that is easy to apply, interpret, and use, and whose purpose is to facilitate fundamental changes in health management. Based on the management concept that inputs, processes, and outputs are quantifiable, the MIS places special emphasis on health system productivity, an essential condition for achieving health coverage that is both adequate and equitable.

Complement-mediated lysis and infectivity for mouse macrophages and sandflies of virulent and attenuated Leishmania major promastigotes varying in expression of the major surface protease and lipophosphoglycan

The infectivity to mouse macrophages and sandflies, the expression and enzymatic activity of the major surface glycoprotein (gp63), the developmental modification of lipophosphoglycan (LPG) and three metacyclogenesis markers (promastigote body size, lectin agglutination and complement resistance) were compared in four related Leishmania major promastigote lines. The lines, which differed in their virulence for BALB/c mice, were examined in both logarithmic and stationary phase. Although the two non-virulent lines were unable to survive and multiply within the macrophages, they were better at attaching to the macrophages and infecting sandflies than the two virulent lines, which were highly infective for macrophages. Except for the higher resistance of the attenuated parasites to complement-mediated lysis, there were no clear differences between the metacyclogenesis markers of the four lines. The amount and enzymatic activity of surface gp63 was relatively high in the attenuated promastigotes and this appears to be related to a higher expression of gp63 genes. In terms of LPG, cells of all the lines had approximately twice the number of galactose and mannose residues per molecule when in logarithmic phase than when in stationary phase. LPG of the virulent lines also contained approximately twice the mannose and galactose residues of the attenuated line. Although L. major gp63 could therefore be important for promastigote survival in the sandfly and for the resistance to complement-mediated lysis, there was no apparent correlation between gp63 expression and promastigote survival in the macrophage. A very elongated LPG could be necessary for the survival and proliferation of the parasite in macrophages.