UV-R mitigation strategies in encapsulated embryos of the intertidal gastropod Acanthina monodon: A way to compensate for lack of parental care

Intracapsular embryonic development in the intertidal zone exposes embryos to various stress sources characteristic of this environment, including UV-R. They require defensive mechanisms to mitigate its adverse effects. The presence of total carotenoids (TC), and mycosporine-like amino acids (MAAs) was studied in adults, in encapsulated embryos, and in the egg capsule walls of the intertidal gastropod Acanthina monodon. Oxygen consumption rates (OCR) were determined in encapsulated and excapsulated embryos exposed to photosynthetically active radiation (PAR) and PAR + UV-A + UV-B to understand if the capsule wall is a protective structure for encapsulated embryos. The results showed the presence of TC in adult pedal and gonad tissues, and in all encapsulated stages. MAAs were not detected. The physical structure of the capsule wall retained most wavelengths, being particularly efficient in the UV-B range. Excapsulated embryos exposed to PAR + UV-A + UV-B radiation increased its OCR compared to encapsulated embryos, indicating the protective character of the capsule wall.

FRI0441 INFECTIOUS DISEASES RISK ASSESSMENT PRIOR TO IMMUNOMODULATION THERAPY - EXPERIENCE FROM AN INFECTIOUS DISEASES UNIT

Background:

The increasing use of immunomodulatory therapies has motivated the development of strategies to assess and prevent infectious diseases in these immunosuppressed patients, in whom the risk of serious infections is higher.

Objectives:

The aim of this study was to recognize the need to standardize prophylactic and therapeutic strategies in this population.

Methods:

Retrospective review of clinical files of patients evaluated in the infectious risk assessment in an outpatient clinic at the Infectious Diseases Unit at Hospital de Curry Cabral in Lisbon, between June 2016 and November 2019. We reviewed information regarding sex, age, origin, occupation, past travels as well as plans of future ones, contact with live animals, intake of unpasteurized products or unsafe drinking water, along with relevant data regarding past medical history and previous and/or ongoing treatments, including immunomodulatory ones.

Results:

During the established timeline,1305 appointments were carried out, corresponding to a total of 415 patients. The majority of patients were female (263; 63.7%), the average age was 50 years and 82% were of Portuguese nationality. The most frequent groups of diseases were autoimmune/inflammatory (84.1%) and demyelinating (10.1%). At the date of the first consultation, 70% were already under immunosuppression. Screening for latent tuberculosis infection (LTBI) was done in 99% of the patients (n = 410) and treatment was proposed to 160 patients (38.5%). At the time of screening, 56,8% of the patients were under immunossuppressive therapies, which included high doses of systemic corticosteroids (37%), anti-TNF alpha (7,7%) and combine therapy with non-biologic agents. Active disease was diagnosed and treated in two patients. Interferon gamma release assay test (IGRA) was positive in 56.8% of patients (n = 91), negative in 32.5% (n = 52) and indeterminate in 7.5% (n=12). Of the 69 patients (43%) with indeterminate/negative or not performed IGRA, Mantoux test (TST) was positive in 48 patients. In the remainder, the treatment proposal for LTBI was based on clinical, epidemiological or radiological signs suggestive of past infection.

In order to prevent hyperinfection/disseminated strongyloidiasis, 354 individuals were screened withStrongyloides stercoralisserology, of which 51 patients (14.4%) had a positive result and were treated with ivermectin. Regarding vaccination, the recommendation for annual influenza vaccination was reinforced, together with the prevention of invasive pneumococcal disease. In view of future travelling plans, vaccination against yellow fever (n = 10), meningococcal disease (n = 7), typhoid fever (n = 6), and polio (n = 2) was recommended. In cases without a previous history of measles and according to the year of birth, VASPR was prescribed to 6 patients. Vaccination to prevent herpes zoster was recommended to 20 patients. After serological evaluation, the vaccine against hepatitis A and hepatitis B was prescribed to 89 and 132 patients, respectively, the latter when serological evidence of previous vaccination or contact was absent. We identified 10 cases of positive anti-HCV antibodies, with undetectable viral load. Primary prophylaxis forPneumocystis jiroveciipneumonia was recommended to 104 patients. Prophylaxis against reactivation of Herpes simplex infection was initiated in 4 patients.

Conclusion:

The decision to start immunosuppressive therapy comes with benefits and risks. Appropriate screening prior to starting therapy is an essential tool for its safe use. Referral to a specialised Infectious Risk Assessment consultation should be done promptly in order to review and address accordingly the risk of specific infections taking in to account the patients clinical and epidemiologic history.

Disclosure of Interests:

None declared

Long-term decline of the Amazon carbon sink

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Fast demographic traits promote high diversification rates of Amazonian trees

The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits – short turnover times – are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rates are either constant or decline over time, and occurs in a wide range of Neotropical tree lineages. This finding reveals the crucial role of intrinsic, ecological variation among clades for understanding the origin of the remarkable diversity of Amazonian trees and forests.

The effect of vinyl acetate in acetoclastic methanogenesis

The influence of vinyl acetate (VA) in the methanogenesis was evaluated, by using an upflow anaerobic sludge blanket reactor of 1.5L. The reactor was operated at 33.5 g/L volatile suspended solids to 30±2 °C, a hydraulic residence time of 1 day, an organic loading rate of 1 kgCOD/m3/d of two different mixtures of VA and glucose. The VA was methanized to 81% when its proportion was of 10% into reactor loading rate, when VA proportion increased to 25%, the methane production rate decreased to 62% and the acetate production rate increased almost 8 times. These results indicated that VA was only hydrolyzed and glucose was not used as a co-substrate. The effect of glucose on VA methanogenic degradation was evaluated through batch reactors of 60 mL, concluding that the glucose supported the methanogenesis without favoring the VA elimination. On the other hand, the results of the sludge from the reactor in the presence of VA demonstrated that VA caused an irreversibly inhibition of acetoclastic methanogenesis when the anaerobic sludge was exposed to this compound.

Effect of thermal alkaline pretreatment on the anaerobic digestion of wasted activated sludge

The effect of alkaline pretreatment of waste-activated sludge, using two models to study the sequential hydrolysis rates of suspended (Sanders' surface model) and dissolved (Goel's saturation model) solids, on the mesophilic and thermophilic anaerobic digestion rate is evaluated. The pretreatment, which reduces the size of the solids, increases the reaction rate by increasing the surface area and the specific surface hydrolysis constant (K(SBK)); at thermophilic conditions from 0.45 x 10(-3) kg m(-2) d(-1) for the fresh sludge to 0.74 x 10(-3) kg m(-2) d(-1) for the pretreated sludge and at mesophilic conditions these values are 0.28 x 10(-3) kg m(-2) d(-1) and 0.47 x 10(-3) kg m(-2) d(-1) confirming the usefulness of a pretreatment for solids reduction. But for soluble solids, the thermoalkaline pretreatment decreases the reaction rates by inducing a competitive inhibition on the thermophilic anaerobic digestion rate while in the mesophilic range, a non-competitive inhibition is observed. A mathematical simulation of the consecutive reactions, suspended solids to dissolved solids and to methane in staged anaerobic thermophilic-mesophilic digestion, shows that with 4% suspended solids concentration it is better not to use a thermoalkaline pretreatment because overall solids reduction and total methane production are not as good as without pretreatment.

Drought-mortality relationships for tropical forests

*The rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. *We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119 monitoring plots in 10 countries concentrated in Amazonia and Borneo. *In most sites, larger trees are disproportionately at risk. At least within Amazonia, low wood density trees are also at greater risk of drought-associated mortality, independent of size. For comparable drought intensities, trees in Borneo are more vulnerable than trees in the Amazon. There is some evidence for lagged impacts of drought, with mortality rates remaining elevated 2 yr after the meteorological event is over. *These findings indicate that repeated droughts would shift the functional composition of tropical forests toward smaller, denser-wooded trees. At very high drought intensities, the linear relationship between tree mortality and moisture stress apparently breaks down, suggesting the existence of moisture stress thresholds beyond which some tropical forests would suffer catastrophic tree mortality.

Drought sensitivity of the Amazon rainforest

Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 x 10(15) to 1.6 x 10(15) grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.

Biological wastewater treatment for removal of polymeric resins in UASB reactor: influence of oxygen

The biological elimination of polymeric resins compounds (PRC) such as acrylic acid and their esters, vinyl acetate and styrene under methanogenic and oxygen-limited methanogenesis conditions was evaluated. Two UASB reactors (A and B) were used and the removal of the organic matter was studied in four stages. Reactor A was used as methanogenic control during the study. Initially both reactors were operated under methanogenic conditions. From the second stage reactor B was fed with 0.6 and 1 mg/L.d of oxygen (O2). Reactor A had diminution in chemical oxygen demand (COD) removal efficiency from 75+/-4% to 37+/-5%, by the increase of PRC loading rate from 750 to 1125 mg COD/L.d. In this reactor there was no styrene elimination. In reactor B the COD removal efficiency was between 73+/-5% and 80+/-2%, even with the addition of O2 and increase of the PRC loading rate, owing to oxygen being used in the partial oxidation of these compounds. In this reactor the yields were modified from 0.56 to 0.40 for CH4 and from 0.31 to 0.60 for CO2. The O2 in low concentrations increased 40.7% the consumption rates of acrylic acid, methyl acrylate and vinyl acetate, allowing styrene consumption with a rate of 0.103 g/L.d. Batch cultures demonstrated that under methanogenic and oxygen-limited methanogenesis conditions, the glucose was not used as an electron acceptor in the elimination of PRC.

Sulphide and oxygen inhibition over the anaerobic digestion of organic matter: influence of microbial immobilization type

Two different types of microbial aggregates (granular sludge and biofilm onto a plastic matrix) were evaluated for their susceptibility to sulphide and dissolved oxygen. Their specific methanogenic and sulphate reducing activities were evaluated separately and simultaneously. Total sulphide concentrations that caused 50% loss of methanogenic activity were 800 and 1250 mg l(-1) and for sulphate reduction 750 and 860 mg l(-1) for the granular sludge and the attached biomass, respectively. Simultaneous methanogenesis and sulphate reduction resulted in an increased tolerance of the sulphate reducing process towards sulphide. Results suggest that methanogenesis in granular sludge is less resistant to sulphide than in the attached biomass structure, whereas in sulphate reduction the attached biomass exhibited a better tolerance to high concentrations of total sulphide than the granular sludge. The better sulphate reducing capacity in the attached biomass may suggest that biomass was selectively attached. The dissolved oxygen concentration that inhibited 50% the methanogenic activity was 4.9 and 6.4 mg l(-1) for the granular sludge and attached biomass, respectively. When methanogenesis and sulphate reduction were carried out simultaneously, the whole process was not affected by the supplied oxygen, as produced sulphide was used by sulphide oxidizing microorganisms thus scavenging oxygen. Results showed that the integration of anaerobic/aerobic conditions in a single bioreactor is quite possible and can be used as a good strategy for the complete transformation of sulphate to elemental sulphur.

Anti-chromatin antibodies in systemic lupus erythematosus: a useful marker for lupus nephropathy

BACKGROUND

Anti-chromatin antibodies have recently been described in patients with systemic lupus erythematosus (SLE) and it has been suggested that their presence is associated with lupus nephritis.

OBJECTIVE

To assess the prevalence and clinical associations of these antibodies in SLE.

METHODS

The presence of anti-chromatin antibodies in 100 patients with SLE was investigated by an enzyme linked immunosorbent assay (ELISA). To determine the specificity of these antibodies, 100 patients with primary Sjögren's syndrome, 30 with primary antiphospholipid syndrome (APS), 10 with systemic sclerosis, and 100 normal controls were also tested.

RESULTS

Positive levels were detected in 69/100 (69%) patients with SLE. In contrast, they were found in only 8/100 (8%) of those with primary Sjögren's syndrome, in 1/10 (10%) with systemic sclerosis, in 2/30 (7%) with primary APS, and in none of the 100 healthy controls. Patients with anti-chromatin antibodies had a twofold higher prevalence of lupus nephropathy than those without these antibodies (58% v 29%, p<0.01). A significant correlation was found between the levels of anti-chromatin antibodies and disease activity score as measured by the European Consensus Lupus Activity Measurement (ECLAM; p=0.011).

CONCLUSIONS

The measurement of anti-chromatin antibodies appears to be a useful addition to the laboratory tests that can help in the diagnosis and treatment of SLE. These antibodies are both sensitive and specific for SLE, and are a useful marker for an increased risk of lupus nephritis.

Suicide attempts in bipolar patients

BACKGROUND

Between 25% to 50% of patients with bipolar disorder make suicide attempts during their lives, but there are some controversies about factors related to suicide attempts in this group of patients. The aim of this study is to investigate the association between suicide attempts and the predictive factors previously described in the literature.

METHOD

The sample included all 169 patients with DSM-III-R bipolar I disorder identified in a delimited area (northern Spain). Sociodemographic, clinical, and family history variables measured by Research Diagnostic Criteria-Family History were analyzed. Significant variables were introduced in a logistic regression analysis to control for the effects of other variables.

RESULTS

There were 56 patients (33%) who had one or more suicide attempts. Early age at onset, history of hospital admission during depressive episodes, drug abuse, and family history were significantly associated with suicide in the univariate analyses (p < .05). A much higher proportion of patients with onset at or before 25 years of age than patients with onset after 25 years of age attempted suicide (23% vs. 10%). The age at onset was no longer significant after controlling for the other 3 variables included in the logistic regression analysis.

CONCLUSION

Suicide attempts are highly prevalent in bipolar patients and are related to drug abuse, family history of affective disorders, and severe depressive episodes. This study suggests that the risk of suicide in patients with an early age at onset could reflect other variables such as drug abuse, a history of hospital admissions for depression, or family history.

Biomechanical and biochemical pulping of sugarcane bagasse with Ceriporiopsis subvermispora fungal and xylanase pretreatments

Sugarcane bagasse was pretreated with both the white-rot fungus, Ceriporiopsis subvermispora, and xylanase enzyme for 2 weeks before soda chemithermomechanical (CTMP) and soda chemical (CP) cooking. For fungi-CTMP (BCTMP) and enzyme-fungi-CTMP (EBCTMP), the bagasse, after bio-pretreatment, was cooked with 5% sodium hydroxide, at 130 degrees C for 20 min. For the chemical pulping (CP), after fungi pretreatment (BCP) or after xylanase and fungal pretreatment (EBCP), the bagasse was cooked with 14.5% sodium hydroxide. With the BCTMP, the Klason lignin was reduced, all of the pulp strength properties were increased, and a 28% savings in refining energy consumption was obtained, but the brightness was reduced 5 points compared to the control. With the EBCTMP, the brightness losses were overcome but with a mild reduction in the pulp strength properties compared to the BCTMP. The energy savings were 5% greater than from BCTMP and 33% over the control. The BCP treatment increases somewhat the pulp strength properties, reduces the energy consumption 23%, and reduces the brightness by 9 points compared to the control; however, the kappa no. was 5.5 points higher than the control. EBCP treatment reduces brightness losses and increases the pulp yield 2% compared to the control, but with some reduction in the strength properties compared to BCP.

Phenotypic analysis of peripheral CD4+ CD8+ T cells in the rat

Among peripheral T cells, the expression of CD4 and CD8 is almost mutually exclusive. However, here we show, using flow cytometric analysis, that ex vivo approximately 6% of rat T cells stained for both CD4 and CD8. These double positive cells were also detected by confocal microscopy. Only around 50% of double positive cells expressed the CD8beta chain, the remaining cells expressed the CD8alpha chain alone. Double positive cells were blast-like with a phenotype, distinct from that of either CD4 or CD8 single positive cells, suggestive of an activated state. Previous reports of double positive T cells have also suggested that coexpression of CD4 and CD8 is linked to the activation state of the cell. There was an indication that priming animals with a hapten-carrier complex increased the ratio of CD8alphaalpha : alphabeta expressing double positive T cells, although we did not detect an increase in the frequency of double positive T cells following priming. We also show that the frequency of double positive cells was reduced following thymectomy and with age. In conclusion, these studies show that peripheral T cells expressing both CD4 and CD8 can be detected in the rat and that they are phenotypically distinct from CD4 and CD8 single positive T cells.

Recirculatory and sessile CD4+ T lymphocytes differ on CD45RC expression

CD4+ T cell subsets are unequally distributed in rat secondary lymphoid organs. Those with the memory phenotype CD45RClow Thy-1- L-selectin- are present at a higher frequency in Peyer's patches (PP) than in lymph nodes and spleen, and increase in numbers with age in all three tissues, particularly in the PP. Homing experiments revealed that CD4+ T cells that recirculate through secondary lymphoid organs are mainly CD45RChigh. It was also apparent that the ability of recirculating cells to enter different lymphoid organs varies; less cells enter PP than the spleen or lymph nodes. Our results also reveal the existence of a nonrecirculating population of CD4+ T cells in secondary lymphoid organs, which are predominantly, if not exclusively, CD45RClow. Our results show that secondary lymphoid organs differ in their CD4+ T cell subset composition as a consequence of having different ratios of recirculatory:nonrecirculatory CD4+ T cells, and these cells display a different CD45RC phenotype.

Induction of resistance to active experimental allergic encephalomyelitis by myelin basic protein-specific Th2 cell lines generated in the presence of glucocorticoids and IL-4

We have produced T cell lines with a Th2 phenotype in the presence of IL-4 and the glucocorticoid dexamethasone (DEX). IL-4 and DEX together were more effective in inducing a Th2 response than IL-4 alone. Myelin basic protein (MBP)-specific Th2 lines were obtained and their ability to induce experimental allergic encephalomyelitis (EAE) was studied. Lines treated with IL-4 and DEX did not transfer passive EAE and did not induce cellular infiltration into the central nervous system as opposed to the encephalitogenic Th1 lines. Lines treated with IL-4 and DEX did not protect animals from the effect of encephalitogenic Th1 lines when the two were injected together. However, a high proportion of animals injected with IL-4 + DEX-treated lines became refractory to the development of EAE after immunization with MBP; that is, it was possible to induce resistance to active EAE without prior episodes of disease. Interestingly, animals injected with T cell lines had accelerated antibody responses against MBP and the predominant isotype was dependent on the cytokines synthesized by the T cell line injected. There was not evidence that the resistance to active EAE was due to anergy of MBP-reactive cells or the action of CD8+ cells. Our data suggest that MBP-specific T cell lines prevent the induction of disease by deviating the reactivity to MBP from a cell-mediated to a humoral one and not merely from a Th1 to a Th2 response.

[Clinical findings in active cerebral neurocysticercosis in pediatrics]

OBJECTIVE

We describe our experience in the study of active cerebral cysticercosis in paediatrics over a period of 6 years, involving a total of 85 cases, which were studied from the clinical, immunological and radiological points of view. The aim of this communication is to present the clinical characteristics of the disorder and its course when symptomatic treatment is given.

DEVELOPMENT

The commonest age of presentation was school age. However, we had a large number of children under 4 years old. This shows that there is considerable endemicity in a group in which the disorder is considered to be less frequent. There were slightly more females than males, which is in accordance with another Mexican series. The predominant socio-economic level was poor (59%). The patients come from urban areas more and more frequently. The commonest signs were: convulsive crises, intracranial hypertension and headache without intracranial hypertension. The commonest type of crisis was partial, in its different forms.

CONCLUSIONS

The course was mild and satisfactory in 90% of the patients. The good clinical progress was independent of the use of antiparasitic treatment.

Rat interleukin-4 assays

The present article describes procedures to measure rat IL-4 protein. The RT-PCR technique has been successfully and widely used to measure IL-4 mRNA, but it does not determine IL-4 protein synthesis. Assays to measure rat IL-4 protein based on its biological activity were developed using the mAb OX-81, which inhibits rat IL-4 activity. Two bioassays were attempted based on the ability of IL-4 to induce the proliferation of T cell blasts and to increase MHC class II expression on resting B cells. A second mAb against rat IL-4 was used in a sandwich ELISA to detect rat IL-4. This ELISA is satisfactory although its sensitivity is not as high as that of the bioassay. According to our experience, the bioassay based on the induction of class II MHC molecules on B cells is the technique of choice for rat IL-4 determination because it proved specific, sensitive and reproducible.

Glucocorticoids induce a Th2 response in vitro

Purified rat CD4+ T cells were activated in vitro, by the polyclonal mitogen Concanavalin A (Con A) or by mixed lymphocyte reaction (MLR), in the presence or absence of the glucocorticoid dexamethasone (DEX). They were then expanded in IL-2 and subsequently restimulated, this time in the absence of the hormone. The results indicate that the exposure of the cells to DEX in the primary stimulation changed the cytokine synthesis induced by the secondary stimulation. IL-4 production was increased by the pretreatment whereas synthesis of IFN-gamma was diminished. Addition of DEX in the second activation suppressed all cytokine production. In brief, the transient presence of glucocorticoids in the culture induces a change in the pattern of cytokine production but the continuous presence causes inhibition of cytokine synthesis. Further studies in which IL-4 was used together with DEX showed that the cytokine potentiated the effect of the hormone. The data here presented suggest that glucocorticoids and the neuroendocrine system may be expected to have long-term immunological effects as well as short-lived immunosuppressive ones. High concentration of glucocorticoids suppress cytokine production but when steroids return to basal levels the immune response is directed in a way that favors Th2-type reactions. Possible implications regarding the immune response to pathogens and autoantigens are discussed.

[Positive and negative symptoms in schizophrenia: standards of change during acute exacerbation]

INTRODUCTION AND OBJECTIVES

The temporal stability of the positive and negative symptoms in schizophrenia deserves a special interest due to its consequences in the outcome and the treatment of the disease. This study determines the temporal stability of positive/negative subtypes in schizophrenia during the acute phase.

MATERIAL AND METHODS

This is a clinical, observational and prospective study of a dynamic cohort of patients with acute exacerbation of schizophrenia defined by DSM III-R criteria. Patients with severe and unstable organic pathology, substance dependence, mental organic disorder, mental retardation, depression, or medicamentous parkinsonism were excluded. Clinical assessment was performed with the PANSS scale. Schizophrenic subtypes were established according to inclusive and restrictive criteria of PANSS. All patients were treated with new antipsycotics and biperiden if necessary.

RESULTS

51 patients were assessed for 8 weeks. In the baseline, the negative subtype (63.3% and 52.5% by inclusive and restrictive system respectively) and paranoid form (45.1%) were predominant. Three types of analysis were performed to determine the temporal stability: 1. Concordance (Kappa index). The concordance of the inclusive and restrictive System, regarding to the baseline assessment, indicated that both criteria had a low temporal stability. 2. Mc Nemar Ji Square. This test showed that these changes were bi-directional except for the first visit, which was significant through the restrictive system (higher change from the negative to other subtypes). 3. Transition analysis among groups by First Order Morkov Chains analysis indicated that this change was stationary (the change was the same in all phases).

CONCLUSIONS

1o The variable "time" has to be considered for the definition of subtypes in schizophrenia. 2o The restrictive system is more specific. It allows to identify a subgroup of patients with "Negative" schizophrenia with a high specificity and validity in clinical and epidemiological studies. 3o The use of the baseline visit as a reference (gold standard) is recommended because it exits a higher concordance among criteria and a more florid psychopathology.

[Predictors of rehospitalization in schizophrenia]

OBJECTIVES

The aim of this study is to determine the predictive value on rehospitalization of sociodemographic variables, positive/negative symptoms and thought disorders. The results are part of research project founded by the Basque Health Department.

METHODS

A 18 month follow-up study of a cohort of 60 patients with acute exacerbation of schizophrenia was carried out. The assessment was performed with DSM III-R diagnostic criteria, PANSS and CGI rating scales, and SCID-P semistructured interview. All patients received antipsychotic treatment. The sociodemographic and disease data, the dimensional score of the PANSS subscales, the score of CGI scale, the items 2, 12, 13 and 14 of the PANSS as indicators of formal thought disorders; and the items 1, 5, 6, 17 and 23 of the PANSS as content thought disorders were established as predictors. The predictive value was determined by the Cox regression test (Lee 1992).

RESULTS

We did not find predictive value either in the PANSS scores or in the 9 thought disorders evaluated (Wald and RR tests were not significative). Nevertheless, considering the values of standard error obtained in the Cox regression we were not in a position to assure that they did not have an incidence in the hospitalizations. The CGI was the only scale that showed prognostic value (Wald test = 1.9945; RR = 1.7499). Our results indicated that the lower number of previous hospitalizations (Wald test = 1.1437; RR = 1.1437) and the high level of studies (Wald test = 2.4258; RR = 1.8052) diminished the risk of rehospitalization.

CONCLUSIONS

1 o The predictive value on rehospitalization for the positive/negative symptoms and thought disorders was not confirmed. 2 o CGI is the only scale with predictive value. That fact makes us consider the importance of what German psychiatrists called "smelling the schizophrenia" or "The smell of schizophrenia". 3 o Our results indicate that the lower number of previous hospitalizations, and the high level of studies diminish the risk of rehospitalization.

Glucocorticoids enhance concanavalin A-induced mitogenic response through the inhibition of nitric oxide production

Glucocorticoids (GC) are known to inhibit mitogen-induced proliferation of T cells. In this study we show two experimental situations where the addition of GC increases lymphocyte proliferation. It has been reported by different authors that rat spleen (SPL) cells proliferate poorly after concanavalin A (Con A) activation. These poor responses have been related to the suppressor activity of macrophages. Similarly, it is known that T-cell proliferation is depressed in the presence of an excess of macrophages in the culture. Here we show that in both experimental situations, the inclusion of dexamethasone (DEX), a synthetic glucocorticoid, in the culture medium enhances the Con A-stimulated proliferation. We provide evidence that this effect is a consequence of the inhibition of nitric oxide (NO) synthesis by the hormone. Furthermore, we also demonstrate that rat SPL cells are inefficient antigen-presenting cells (APC) because of their spontaneous high production of NO. Taken together our results suggest that the effects of GC on T-cell activation may be to promote or inhibit proliferation depending on the level of endogenous NO synthesis. The possible significance of these results is briefly discussed.

Glucocorticoids promote a TH2 cytokine response by CD4+ T cells in vitro

Purified rat CD4+ T cells were activated in vitro in the presence or absence of the glucocorticoid dexamethasone. They were then expanded in IL-2 and subsequently restimulated, this time in the absence of the hormone. The results indicate that the exposure of the cells to dexamethasone in the primary stimulation changed the cytokine synthesis induced by the secondary stimulation. The mRNA levels for IL-4, IL-10, and IL-13 were all increased by the pretreatment, whereas synthesis of IFN-gamma and TNF-alpha was diminished. Further studies in which IL-4 was used together with dexamethasone showed that the cytokine potentiated the effect of the hormone. These data suggest that the neuroendocrine system can influence the cytokine response to pathogens and autoantigens in a way that favors Th2-type reactions. There are similar implications for therapy with glucocorticoids, and these drugs may be expected to have long term immunologic effects as well as short-lived immunosuppressive ones. The production of a mouse mAb, MRC-OX81, against rat IL-4 is also described.

Glucocorticoids promote a TH2 cytokine response by CD4+ T cells in vitro

Purified rat CD4+ T cells were activated in vitro in the presence or absence of the glucocorticoid dexamethasone. They were then expanded in IL-2 and subsequently restimulated, this time in the absence of the hormone. The results indicate that the exposure of the cells to dexamethasone in the primary stimulation changed the cytokine synthesis induced by the secondary stimulation. The mRNA levels for IL-4, IL-10, and IL-13 were all increased by the pretreatment, whereas synthesis of IFN-gamma and TNF-alpha was diminished. Further studies in which IL-4 was used together with dexamethasone showed that the cytokine potentiated the effect of the hormone. These data suggest that the neuroendocrine system can influence the cytokine response to pathogens and autoantigens in a way that favors Th2-type reactions. There are similar implications for therapy with glucocorticoids, and these drugs may be expected to have long term immunologic effects as well as short-lived immunosuppressive ones. The production of a mouse mAb, MRC-OX81, against rat IL-4 is also described.

[Sclerotherapy with 75% ethanol in the control of hemorrhage caused by peptic ulcer disease]

We present our experience using ethanol as sclerosant of non-variceal bleeding lesions of the upper digestive tract and the result of its hemostatic effect when compared with patients who received conventional medical treatment. Since January 1989, 48 patients admitted with active bleeding or signs of high risk for rebleeding (clot or visible vessel) were submitted to sclerosis. The historic control group included patients admitted before 1989, being both groups comparable in clinical and endoscopic characteristics. Surgery was performed in 5 cases of the sclerosis group (10.4%) versus 14 of the control group (37.8%). Five of the patients in the sclerotherapy group died, one of them due to upper G.I. bleeding as the primary cause. We dit not observe a statistically significant difference in hospital stay, transfusion requirements or mortality. There were no complications as a result of the method. Sclerotherapy was not immediately effective in 2 patients; three patients who rebled were subject to new sclerosis, which was effective in controlling bleeding in two of them. In conclusion, sclerosis is a safe and effective method to achieve hemostasis, diminishing the re-bleeding and the need for surgery in cases of digestive bleeding due to peptic ulcer disease. Future studies using larger samples could show decrease in mortality.

[Clinical and prognostic factors of mortality in upper digestive hemorrhage]

In order to investigate prognostic factors we prospectively followed 741 patients with upper gastrointestinal bleeding (UGIB). Eleven variables were identified with mortality predictive value. Hematemesis, age of 50 y/o, more than 120 heart beat/minute, 3 or more units of pack red blood cells, esophageal varices, cirrhotic liver and renal failure had independent predictive value. Our findings could help to identify high risk patients.

[Upper gastrointestinal hemorrhage. Prospective analysis of 741 cases]

A prospective study was performed to evaluate the epidemiological characteristics and clinical outcome of patients with upper digestive bleeding. Between April 1987 and May 1993, 741 patients, 517 men and 224 women, with a mean age of 50.48 years (range, 12 to 94) were admitted to the emergency department with this diagnosis. The chief complaint was tarry stool (88.4%). A total of 717 patients underwent endoscopic examination within a mean time of 17.2 hours of arrival at the emergency department. Duodenal ulcers were found in 216 (35.9%) patients, gastric ulcer in 240 (32.4%), gastritis in 74 (10%), esophageal varices in 38 (5.1%), and other causes in 121 patients (16.5%). 478 required blood transfusion (range of 1 to 15 blood units transfused). 80.4% of patients who died necessitated transfusion versus 62.5% of the patients who had a satisfactory outcome. A total of 672 cases (92%) were managed with medical therapy. In 90 cases (12.2%) endoscopic injection treatment with 75% alcohol was performed. 60 patients (8.18%) had surgical therapy, 81.7% of whom underwent emergency operation to arrest bleeding. The global mortality was 10.6% (78 of 741 patients), compared to 18.3% in patients who were operated. The highest mortality occurred in patients with esophageal varices. We conclude that peptic ulcer is still the mayor cause of upper digestive bleeding. The high mortality found in patients who required surgical therapy creates the need to select those patients who may get benefits of alternate therapies which may improve the outcome.

[The surgical treatment of anterior hypospadias. Apropos 590 cases (1966-1988). The indications and results. The current trends in surgical treatment]

The surgical treatment of hypospadias is very complex. The objective is to obtain a satisfactory urinary and genital function with an equal morphological, anatomical and aesthetic result. Our contribution covers twenty-two years of surgical multicentre experience (590 cases). We evaluate the surgical indication, results, complications, associated malformations and study protocols. We have objectively evaluated the evolution of the indications, as well as the application of different techniques depending on the extent of urethral malformation.

OX48, a monoclonal antibody against a 70,000 MW rat activation antigen expressed by T cells bearing the high-affinity interleukin-2 receptor

The monoclonal antibody (mAb) OX48 recognizes a 70,000 MW cell-surface protein present in a small percentage of activated rat T cells and in CD8+ rat x BW5147 interleukin-2 (IL-2)-dependent T-cell hybridomas, but not in resting spleen cells or in IL-2-independent T-cell hybrids. OX48 antibody added simultaneously with concanavalin A (Con A) to resting spleen cells inhibits the cell proliferation and reduces the IL-2 production. However, addition of IL-2 does not restore the mitogenic response. Growth of rat blast T cells or IL-2-dependent hybrids is not affected by the OX48 antibody. There is a close correlation between the expression of high-affinity IL-2 receptors (IL-2R) and the OX48 antigen in T-cell hybridomas. In spite of this striking correlation, OX48 mAb does not inhibit the binding of 125I-IL-2 to the IL-2-dependent hybrids, and is unable to immunoprecipitate any of the proteins chemically cross-linked to 125I-IL-2. Therefore, the OX48 molecule represents a new rat activation antigen, undefined in other species, and probably involved in the early steps of T-cell activation.

Tooth pulp stimulation advances both medullary off-cell pause and tail flick

It has been postulated that the so-called off-cells of nucleus raphe magnus and adjacent structures in the rat are the output elements of a system which inhibits nociceptive transmission at the spinal cord. Off-cells stop firing about 0.4 s before the tail flick reflex (TF) elicited by the application of noxious heat to the tail. When continuous off-cell activity is induced by either morphine injection or periaqueductal gray stimulation, the TF is delayed. The present results show that electrical stimulation of the tooth pulp (TP) causes the off-cells to stop firing. Furthermore, when TP is stimulated during tail heating and before the expected time for TF, off-cells stop firing earlier and the TF occurs also earlier. This supports the notion that off-cells inhibit nociceptive transmission.

HLA--D typing with homozygous cells identified in an American indigenous isolate. I. Population studies

Lymphocytes from six individuals homozygous for their HLA--A, --B, --C and --D loci belonging to an American indigenous group, the Warao, have been used as typing cells to detect HLA--D determinants in 121 donors from the same indigenous isolate and in 71 donors of mixed ethnic origin living in Venezuela. Two determinants responsible for strong proliferation in mixed lymphocyte cultures have thus been identified. Four HLA--A2, B5 cells (r values between 0l72 and 0.57) identify a determinant provisionally called LD5a showing a gene frequency of 0.30 among the Warao and of 0.09 among the population of mixed ethnic origin. The nearest B locus antigen to this new specificity among the Warao is HLA--B5 (r value = 0.20). A second determinant identified by two HLA--A2, B15 sisters (r values of 0.71) shows a gene frequency of 0.15 among the Warao and of 0.03 among the mixed population. The latter is related to Dw8 as shown by results of the VI and VII Histocompatibility Workshops, and is weakly associated (r value of 0.28) to HLA--B15 among the American indigenous population tested.

[Diagnosis of venous thrombosis by using radioisotopes]

Thromboembolism problem is a grave complication which occurs with great frequency in patients hospitalized in a critical state. The association between periferical venous thrombosis and the thromboembolic accident is plainly demonstrated, although the accurate establishment of the clinical diagnosis of phlebothrombosis is only feasible in 50% of the cases. In the present work, we describe the methodology and the experience which we have acquired with the use of radioisotops in the diagnosis of these problems. We studied 64 patients to whom in the supine position we injected into a vein in both heels, from 3 to 5 millicuries of 99m-Tecnecio, practicing three stages: dynamic venography, a static study, and a pulmonary gammagram. In the normal cases, we clearly identified the tracts of the principal femural, iliac, and the inferior third of the inferior vena cava veins. In the abnormal studies, we observed the obstructive process manifested by the absence of radioactivity in the affected venous tract, with appearence of collateral circulation, definitive data which establishes with certainty the diagnosis. It can be concluded that the method is rapid and easily carried out, meaning that it could be a routine practice in all of those patients who are suspected of having this problem.