Ternary composites of poly(vinylidene fluoride-co-hexafluoropropylene) with silver nanowires and titanium dioxide nanoparticles as separator membranes for lithium-ion batteries

In the realm of polymer composites, there is growing interest in the use of more than one filler for achieving multifunctional properties. In this work, a composite separator membrane has been developed for lithium-ion battery application, by incorporating conductive silver nanowires (AgNWs) and titanium dioxide (TiO2) nanoparticles into a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) polymer matrix. The composite membranes were manufactured by solvent casting and thermally induced phase separation, with total filler content varying up to 10 wt%. The ternary composites composites present improved mechanical characteristics, ionic conductivity and lithium transfer number compared to the neat polymer matrix. On the other hand, the filler type and content within the composite has little bearing on the morphology, polymer phase, or thermal stability. Once applied as a separator in lithium-ion batteries, the highest discharge capacity value was obtained for the 5 wt% AgNWs/5 wt% TiO2/PVDF-HFP membrane at different C-rates, benefiting from the synergetic effect from both fillers. This work demonstrates that higher battery performance can be achieved for next-generation lithium-ion batteries by using separator membranes based on ternary composites.

Subsistence swine farming: seroprevalence and risk factors associated with Lawsonia intracellularis infection in the state of Minas Gerais Brazil in 2016

Although it is considered an economically relevant and prevalent disease, little information is available on the epidemiology and risk factors of porcine proliferative enteropathy (PPE) in commercial pigs, and no publication is available on subsistence pig farming. The objectives of this study were to estimate the seroprevalence of L. intracellularis and identify associated risk factors in backyard pigs in the 12 mesoregions of the state of Minas Gerais, Brazil. Blood from pigs between 2 months and 6 years of age were sampled; an epidemiological questionnaire was applied to 288 properties investigated in 2016. Serum samples were tested for the presence of anti-L. intracellularis antibodies using an immunoperoxidase monolayer assay. The seroprevalence of L. intracellularis was 97.7% (CI 95%: 96.7-98.4), and there was no statistical difference among the prevalence of the sampled mesoregions. Only 3 of the 12 risk factors were significant when samples were analyzed from strongly seropositive animals (≥ 1:120) in a Poisson multivariate regression model. There was an interaction between properties in peri-urban areas and extensive production systems. This interaction demonstrated an increase in prevalence rates by 3.7 times (95%CI: 2.4-5.8). Properties close to dumps demonstrated an increase in prevalence rates by 2.2 times (95%CI: 0.99-4.8). In conclusion, anti-L. intracellularis antibodies were widely dispersed in subsistence pig farming's in Minas Gerais, indicating a wide circulation of the agent in this type of production system. The interactions of animals raised close to peri-urban areas, extensively, and close to landfills are risk factors for spread of PPE.

Contextual and individual determinants of tooth loss in the Afro-descendant older adult populations of different countries: a scoping review

BACKGROUND

The Black population has poorer oral health than other racial groups; however, little is known about the mechanisms that explain this difference.

OBJECTIVE

To study the association between race and tooth loss and map the evidence on factors associated with tooth loss in Black older populations.

METHODS

Scoping review following the PRISMA Extension for Scoping Reviews conducted according to the recommendations of the Joanna Briggs Institute. A three-step search strategy was applied, and data were collected between April and July 2021. Searches were performed in the PubMed, Lilacs, and SciELO databases. The grey literature was searched using Google Scholar (https://www.scholar.google.com/). The reference lists of included studies were used as additional sources. Studies published in English and Portuguese of the association between tooth loss and different racial groups and the factors associated with tooth loss and tooth retention in Black older adult populations were included.

RESULTS

Twenty-one of 913 original articles published between 1995 and 2020 were included. Of these, 75% were research articles, 15% were reports, and 10% dissertations. Eighty per cent reported cross-sectional and 20% longitudinal data. African ancestry was associated with increased odds of tooth loss in older adult populations. Periodontal disease, female sex, and advanced age were the exposures most frequently associated with tooth loss.

CONCLUSION

Race, educational level, advanced age, and oral diseases such as periodontitis are associated with increased tooth loss in Afro-descendant older populations.

In vitro fertilization: an unexpected finding in a cohort of patients with biliary atresia

In biliary atresia (BA), efforts to prevent premature liver transplantation (LT) are aimed at early diagnosis, timing of Kasai-portoenterostomy (KPE), and centralization of care. This report presents the clinical picture, treatment strategies, and outcomes of BA patients with no previous treatment. A retrospective cohort study (Jan/2001 to Jan/2021) was conducted to evaluate the outcome of patients with BA referred to a single team. Study groups were: 1) Kasai-only group (K-only) n=9), 2) LT-only group (n=7), and 3) Kasai+LT group (K+LT) (n=23). Survival with native liver and overall survival were 22.9 and 94.8%, respectively, at 120 months of follow-up. There was no difference in age at KPE in the K-only group (46.8±21.8 days) vs K+LT (52.1±22 days), P=0.4. Ten (25.6%) patients were babies conceived through in vitro fertilization (IVF). Four IVF patients (40%) presented associated congenital heart disease vs 5 patients (17%) in the remaining group (P=0.14). Two of the IVF patients were premature (<37 weeks). Median maternal age at birth was 35 years (33 to 41 years). Excellent patient survival is expected for patients with BA with the available treatment strategies. IVF+BA was an unexpected prevalent association in this cohort, and further studies are required to better understand these findings.

Myocardial infarction in the absence of obstructive coronary artery disease - can the underlying causes be identified by cardiac magnetic resonance?

Funding Acknowledgements

Type of funding sources: None.

Background

 Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease (MINOCA) is a clinical entity that occurs in up to 15% of all acute coronary syndromes (ACS). It is a "working diagnosis", as it is constituted by several etiologies.

Purpose

To identify the utility of CMR in determining the etiological diagnosis of MINOCA events, with potential impact in the therapeutic management of these patients.

Methods

 Patients with MINOCA who were admitted to the Cardiology department at a tertiary center, between 2015 and 2020, were included. MINOCA was defined as an ACS with non-obstructive (&lt;50%) coronary artery disease and no other clinically specific cause, in accordance with definition adopted in the 2020 ESC Guidelines for the management of ACS in patients presenting without persistent ST-segment elevation. Patients who did not had a coronary exam (either CT or invasive angiogram) or a CMR were excluded.  All CMR exams were performed in a 3 Tesla equipment using a comprehensive protocol (cine, T2-weighted, and late gadolinium sequences). Clinical, electrocardiographic, echocardiographic and CMR data were collected.

Results

In a population of 29 patients, the mean age was 55 ± 17 years-old at the time of the cardiac event, 51.7% were male. Concerning to cardiovascular risk factors, 58.6% of patients had dyslipidaemia, 51.7% had hypertension, 13.7% were diabetic, 41.4% were smokers or previous smokers and 31.0% had obesity. Atrial fibrillation was present in 3.4% of patients. As for the EKG patterns, 41.4% of the patients had ventricular repolarization changes, 13.8% had a transitory ST elevation pattern, 6.9% had a complete left bundle branch block and 37.9% had a normal EKG; most of the ischemic EKG alterations were on the anterior wall (66.7%). The median high sensitivity I troponin levels were 1877.5 (IQR 225.3 – 5985.8) ng/L. The majority of patients (58.6%) had echocardiographic wall motion abnormalities; of those, the most common (41.1%) were on the left anterior descendent artery territory. CMR (performed at a median of 5 days from presentation) was able to identify the cause for the troponin rise in 58.6% of the cases; late gadolinium enhancement and oedema were present in 41.4% and 62.1% of patients, respectively. The mean left ventricle ejection fraction (EF) was 57.7 ± 8.5% and the mean right ventricle EF was 61.5 ± 6.1%. An ischemic pattern was present in 29.4% of the total population. In 17.6% of the patients findings were consistent with Takotsubo syndrome and in 29.4% with myocarditis.

Conclusion

 CMR established the etiological cause in 58.6% of the cases, with potential implications in medical therapy. These findings highlight the importance of CMR in MINOCA diagnosis and the potential improvement in patient care with multi-modality imaging.

Factors associated with extubation failure in very low birth weight infants: a cohort study in the northeast Brazil

OBJECTIVES

Identifying and understanding the main risk factors associated with extubation failure of very low birthweight (VLBW) infants in different populations can subsequently help in establishing better criteria while taking decision of extubation. The aim of the study was to identify factors associated with extubation failure in VLBW infants.

METHODS

A cohort study of VLBW infants who underwent their first extubation between April 2018 and December 2019 in a Neonatal Intensive Care Unit, Alagoas, Brazil, were included in this study. Extubation failure was defined as reintubation within seven days of extubation. Relative risks of predictive variables different between the extubation success group (ES) and extubation failure group (EF) were estimated with a robust Poisson regression model.

RESULTS

Out of the 112 infants included, 26 (23%) cases exhibited extubation failure. Extremely low birth weight (RR 2.55, 95% CI 1.07, 6.06), mechanical ventilation duration for first extubation greater than seven days (RR 2.66, 95% CI 1.10, 6.45), vaginal delivery (RR 2.07, 95% CI 1.03, 4.18) and maternal chorioamnionitis (RR 4.89, 95% CI 1.26-18.98) remained independently associated with extubation failure. EF had a significant greater need for respiratory support, longer oxygen therapy duration, more bronchopulmonary dysplasia (BPD) and longer length of hospital stay, even when adjusted for confounding variables.

CONCLUSIONS

Extremely low birth weight infants needing mechanical ventilation, wherein the duration for first extubation was longer than seven days, with vaginal delivery and maternal chorioamnionitis failed more frequently at the first attempt of extubation. And this failure increased the risk of BPD and the length of hospital stay.

Secondary prevention after acute coronary syndrome - can we achieve dyslipidemia guideline targets?

Funding Acknowledgements

Type of funding sources: None.

Lipid control is one of the most important secondary cardiovascular prevention targets. The 4S trialin 1994 was the first study to demonstrate the benefit of statin therapy in coronary artery disease patients. More recently, the FOURIER trial (2017) and the ODYSSEY Outcomes (2018) demonstrated the cardiovascular benefit of adding a PCSK9 inhibitor to optimized antidyslipidemic therapy.

Owing to the growing number of evidence showing the importance of aggressive lipid control, the European Society of Cardiology (ESC) 2019 Dyslipidemia Guidelines changed the recommendation of LDL targets from below 70 mg/dL to below 55 mg/dL in very high risk patients.

In the light of this new recommendation, we retrospectively analysed all patients who participated in a Coronary Rehabilitation Program (CRP) after an Acute Coronary Syndrome at a tertiary center from May 2008 to June 2019. The CRP consisted in a multi-disciplinary approach to these patients, including 8 to 12 weekly sessions of phase II rehabilitation, exercise prescription, nutrition counselling and life-style intervention, with Cardiology follow-up at the end of the CRP (3 months), 6 months and 12 months after the event. Lipid profile was requested at baseline, 3 months and 12 months after the event. Dyslipidemia was defined using the ESC Guidelines definition.

In total, 989 patients were enrolled: the mean age was 54 ± 10 years and 15% were female. Concerning to cardiovascular risk factors, 56.7% of patients had dyslipidaemia, 41.5% had hypertension, 18.1% were diabetic, 73.1% were smokers or previous smokers, 26.0% had family history of coronary disease and 14.0% had previous coronary disease.

At hospital admission, mean LDL concentration was 121,7 ± 38,8 mg/dL with 2,9% of the patients with values below 55 mg/dL and 7,6% below 70 mg/dL. The vast majority of patients were medicated with statin at hospital discharge and maintained the prescription during the follow-up (97.5% and 97.1%, respectively).

At the end of the CRP, there was a significant decrease of LDL values (p &lt; 0.001) with 18.7% patients with LDL below 55 mg/dL and 46.3% below 70 mg/dL (mean LDL 76.6 ±23.6 mg/dL). At 1-year follow-up, the lipid control was better than at admission, but inferior than at the end of the rehabilitation program, both findings statistically significant (11.0% patients were below 55 mg/dL and 33.1% were below 70 mg/dL, with a mean LDL of 82.7 ± 28.3 mg/dL; p &lt; 0.001).

In conclusion, our real-life observational cohort showed that guideline recommended LDL target is not achieved in most of very high-risk patients even in a structured coronary rehabilitation program. Of note, the number of patients at LDL-target decreased from 3 months to 1-year follow-up. This state the importance of a sustained healthy lifestyle and therapy adherence, with aggressive pharmacologic therapy.

Grazing intensity as a management strategy in tropical grasses for beef cattle production: a meta-analysis

Correct pasture management associated with the adjustment of grazing intensity determines pasture persistence and the level of production per animal and per land area. The objective of this review was to examine the effect of grazing intensity in tropical pastures on the performance and productivity of beef cattle by a meta-analytical approach. The review followed a protocol developed and tested based on the PICOS strategy to formulate the guiding question: population (beef cattle), intervention (high grazing intensities), comparison (low grazing intensities), outcome (animal performance and productivity), and study design (experimental). Data were collected from papers published in the electronic databases of SCOPUS (Elsevier), Web of Science (Main collection), SpringerLink, Wiley Online Library, and Science Direct (Elsevier) by a single cross-reference search. The selected studies were considered relevant when they: (1) were primary research published in the format of a research article; (2) included grazing intensities as a management strategy; and (3) evaluated average daily gain (ADG, kg/animal per day), stocking rates (SR, animal unit (AU)/ha; AU = 450 kg), and weight gain per area (WGH, kg/ha). Thirteen manuscripts were selected due to their methodological strength for data extraction. The means under continuous stocking were 0.67 kg/animal per day for ADG, 518.12 kg/ha for WGH, and 4.19 AU/ha for SR. Under intermittent stocking, the means were 0.62 kg/animal per day for ADG, 980.18 kg/ha for WGH, and 5.10 AU/ha for SR. In tropical forages, the heights of 20 to 40 cm for pastures under continuous stocking and the defoliation intensities of 40 to 50% for those under intermittent stocking result in greater individual performance and animal productivity per land area.

Processing Strategies to Obtain Highly Porous Silk Fibroin Structures with Tailored Microstructure and Molecular Characteristics and Their Applicability in Water Remediation

The present work reports on the control of silk fibroin (SF) porous structures performance through various processing methods. The study includes the analysis of two dissolving techniques (CaCl₂/H₂O/EtOH ternary and LiBr/H₂O binary solutions), three regeneration methods (gelation, lyophilization and gas foaming) and one post-processing (EtOH). In all the cases, followed steps lead to SF structures with porosity values above 94% and large surface areas. Also, results about samples microstructure, secondary organization, crystallinity and water behavior, reveal a direct correlation between processing and SF properties. Thanks to the achieved progress, the SF varying porous structures were evaluated for metalloids (As⁵⁺ and As³⁺) and heavy metals (Cr⁶⁺ and Cr³⁺) adsorption, observing a direct relationship between samples processing and ionic species adsorption ability. Thus, it is shown that the control of the properties of SF based porous structures through processing, represents a suitable and ecofriendly approach for the development of bio-based materials for environmental applications.

Crystal morphology control of synthetic giniite for enhanced photo-Fenton activity against the emerging pollutant metronidazole

Metronidazole (MNZ) is a recalcitrant antibiotic with toxic and carcinogenic effects in aquatic environments. In this work, Fe₅(PO₄)₄(OH)₃·2H₂O (giniite) particles were synthesised with three different alkaline cations (Li⁺, Na⁺ and K⁺) and used as Fenton catalysts for MNZ removal. It is shown that the addition of different cations during the hydrothermal synthesis process promote different morphologies from asterisk-like to flower-like and branches-like, maintaining the crystalline structure of pure giniite. The photo-Fenton activity of these particles was then evaluated through the degradation of MNZ under sunlight radiation for 9 h. The results indicate that the alkaline cation has a predominant role in the photo-Fenton efficiency, as demonstrated by the superior degradation efficiencies of Na@giniite particles (91.2% and 72.5% with giniite concentration of 0.2 g L^-1 and 0.07 g L^-1, respectively), related with its high surface area (10.7 m² g^-1). Thus, it is demonstrated the suitability of Na@giniite particles as Fenton catalyst for MNZ removal from water.

Enhanced ionic conductivity in poly(vinylidene fluoride) electrospun separator membranes blended with different ionic liquids for lithium ion batteries

Electrospun poly(vinylidene fluoride) (PVDF) fiber membranes doped with different ionic liquids (ILs) and sharing the same anion were produced and their potential as separator membranes for battery applications was evaluated. Different types of ILs containing the same anion, bis(trifluoromethylsulfonyl)imide [TFSI]^-, were used with IL concentrations ranging between 0 and 15 wt% The morphology, microstructure, thermal and electrical properties (ionic conductivity and electrochemical window) of the membranes were evaluated. The presence of ILs in the PVDF polymer matrix influences the fiber diameter and the content of the polar β phase within the polymer, as well as the degree of crystallinity. The thermal stability of the membranes decreases with the incorporation of IL. Impedance spectroscopy tests show a maximum ionic conductivity of 2.8 mS.cm^-1 for 15% of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) at room temperature. The electrochemical stability of the samples ranges from 0.0 to 6.0 V. When evaluated as battery separator membranes in C-LiFePO₄ half-cells, a maximum discharge capacity of 119 mAh.g^-1 at C-rate was obtained for the PVDF membrane with 15% [Emim][TFSI], with a coulombic efficiency close to 100%. The results demonstrate that the produced electrospun membranes are suitable for applications as separators for lithium ion batteries (LIBs).

Environmental factors that influence milk production of Pantaneiro ewes and the weight gain of their lambs during the pre-weaning period

The main objective of this research was to conduct an exploratory study of the lactation curve in order to characterize the productive potential of Pantaneiro ewes and lambs. Fifty ewes were bred using four rams in two different mating seasons. The ewes were kept with their lambs on pasture of Brachiaria brizantha. Ewe body score, ewe weight, and lamb weight were evaluated. Milk sampling was performed every week. In the morning for milk collections, the ewes were treated with 1 UI of oxytocin (intramuscular) for complete milking. Lambs were separated from the ewes for 4 h and milk collections were performed. The total milk production over 24 h was estimated by multiplying the production of this period (4 h) by 6. The data were analyzed using the MIXED procedure (P < 0.05) in SAS. Milk production data were fitted to the curve using the incomplete gamma function of Wood, and lamb growth data were fitted using the Gompertiz equation. The average milk production of the ewes was 1.03 kg/day^-1. Younger ewes had the lowest milk production (18 = 798 ± 330, 24 = 1001 ± 440, 36 = 1100 ± 490, and 48 = 1106 ± 490 g/day^-1). Ewe body score at lambing affected initial milk production (1.0 = 816 ± 660, 1.5 = 1089 ± 105, and 2.0 = 1424 ± 1600 g/day^-1). Lambs were weaned with an average weight of 20.3 kg. Daily weight gain from birth to weaning was 181 g. Locally adapted Pantaneiro ewes showed a linear decreasing lactation curve, with reduced production from the second week of lactation. Overall, evaluation of the dairy production and lamb performance revealed great variation, denoting potential for selection.

Nanoparticle dispersion and electroactive phase content in polyvinylidene fluoride/Ni0.5Zn0.5Fe2O4 nanocomposites for magnetoelectric applications

Ni0.5Zn0.5FeO4 ferrite/polyvinylidene fluoride composite films were prepared by a solution method and melt processing. As nanoparticle dispersion and polymer electroactive phase content are some of the key factors for improving magnetoelectric coupling in the composites, the dispersion of ferrite nanoparticles in the polymeric matrix was studied by preparing samples by two alternative dispersion routes: ultrasound and citric acid nanoparticle surfactation. The nucleation of the electroactive beta-phase of the polymer was observed in composites produced by nanoparticle dispersion by ultrasound. This fact avoids the need of stretching composites at elevated temperature in order to obtain the electroactive phase and obtain magnetoelectric composites. By this method, nevertheless, large nanoparticle agglomerates are obtained. Nanoparticle dispersion is largely improved by citric acid surfactation of the nanoparticles. On the other hand, the beta-phase of the polymer is not nucleated due to the modification of the nanoparticle-polymer interaction due to the presence of the surfactant.

Effect of zeolite content in the electrical, mechanical and thermal degradation response of poly(vinylidene fluoride)/NaY zeolite composites

Polymer based composites of a-PVDF doped with different NaY zeolite (Na53Al53Si139O384) content were investigated. A good dispersion of NaY zeolite within the polymer matrix is achieved. The introduction of NaY nanoparticles enhance the storage modulus and the dielectric constant at room temperature. The dielectric constant at room temperature increases up to the value of 500 for the 32 wt% composite, at 1 kHz. The increase of the dielectric constant is mainly attributed to interfacial polarization effects. For increasing zeolite content, the nanocomposite conductivity shows two conducting regimes separted by the so called breaking voltage, which is associated to an intrazeolite charge transport. Thermogravimetric results show that the introduction of zeolites affects the thermal degradation of the polymer for low zeolite contents and also indicate the presence of water that also plays an important role in the electrical response of the materials.

[Hepatic hemangioma]

OBJECTIVE: To describe a case of a congenital hepatic hemangioma treated with surgery. METHODS: We report the case of a 6-day-old boy who presented a giant hepatic hemangioma, and describe its evolution. RESULTS: The child developed hemodynamic instability secondary to consumption coagulopathy and respiratory failure. The image studies were inconclusive. He was submitted to surgery with complete resection of the tumor. Pathology confirmed it was hemangioma. The child was discharged after 15 days and is well, without symptoms. CONCLUSIONS: Hepatic hemangiomas should be treated conservatively, with surgery reserved for intractable cardiac failure and/or refractory consumptive coagulopaty.

Lack of hematologic effects of recent ethanol ingestion by trauma patients

A retrospective investigation was conducted to determine if acute ethanol (EtOH) ingestion before injury leads to hematologic impairment as noted by coagulation and transfusion parameters. Patients older than 18 years of age were grouped according to the presence or absence of detectable EtOH concentrations in the blood, with further subdivision based on an Injury Severity Score of 8 or less or 9 or more. The following direct and indirect indicators of hematologic function were studied: volume of resuscitation fluids administered (including blood products), prothrombin time, partial thromboplastin time, and hematocrit. Of the 304 patients who were evaluated, 152 had detectable EtOH concentrations and 136 had undetectable EtOH concentrations; 16 patients had not been tested for blood EtOH concentrations and were excluded from the analysis. There were no significant differences between groups with regard to blood or fluid requirements or coagulation parameters. Detectable blood EtOH concentrations in trauma patients are not associated with significant changes in transfusion requirements or coagulation parameters compared to patients without detectable EtOH concentrations.

Sporadic Creutzfeldt-Jakob disease. A clinico-neuropathological analysis of nine definite cases

The authors have analyzed clinico-neuropathologically nine cases of the definite sporadic form of Creutzfeldt-Jakob disease (CJD). All cases were female, with mean age of 62.7 years. Eighty-nine percent of the patients exhibited prodromal and initial psychiatric symptoms; definite signs of dementia, and myoclonus were present in 100% of cases. The EEG was abnormal in all cases and pseudoperiodic paroxysms were present in 56% of the patients. Their evolution time ranged from 3 to 19 months. Neuropathologically, brain and cerebellar atrophy, spongiosis, astrocytosis and neuronal loss were present in 100% of the patients. In 5 (56%) of these 9 cases, prion protein (PrP) amyloid plaques were detected in the cerebellum, by optical- and electronmicroscopy. There was a positive correlation between the number of plaques and the evolution time. The authors outline the similarities of their cases in the elderly with the new variant of CJD described in young people.

Experimental HTLV-I infection and associated myelopathy

HTLV-I infection and associated myelopathy has been reproduced experimentally in vitro and in vivo and these studies have shown the possibility of creating several lines of infective cells and of detecting minor and major clinical expressions of HTLV-I associated myelopathy in rabbits and rats.

Abdominal recurrence of osteogenic sarcoma: a case report

PURPOSE

Nonpulmonary metastases from osteogenic sarcoma are rare. A patient had a localized osteogenic sarcoma of the left femur which recurred in the abdomen, a previously unreported metastatic site.

PATIENT AND METHODS

An 18-year-old boy was treated for osteosarcoma. He had abdominal pain, vomiting, weight loss, and symptoms of intestinal obstruction at the time of relapse.

RESULTS

The patient had diffuse widespread intraabdominal osteogenic sarcoma as the only site of initial recurrence. Abdominal computerized tomography revealed ascites and calcified masses on the hepatic and peritoneal surfaces. Laparoscopic visualization of the abdomen showed hemorrhagic ascites and multiple calcified tumor on the peritoneum, diaphragm, and liver. A biopsy of a representative lesion confirmed the diagnosis of osteogenic sarcoma. The patient died from progressive disease.

CONCLUSION

As the initial treatment for patients with osteogenic sarcoma is intensified, the pattern of metastases may change. Unusual sites of recurrence such as in this patient may become more prevalent. A clinical presentation of an acute abdomen in a patient previously treated for osteogenic sarcoma should prompt suspicion of intraabdominal recurrence.

Discrepancy, coincidence or evidence in chronic idiopathic spastic paraparesis throughout the world. A meta-analysis on 2811 patients

HTLV-I has been associated with a chronic idiopathic spastic paraparesis (CHISPA) in man; however, a complete understanding of this association is still debated. We selected the most comprehensible papers on this topic between 1985 and 1996, and found that 1261 out of 2811 patients (44.9%) reported, throughout the world, were HTLV-I positive. The mean age was 39.5 years and there was a female predominance of 1.9:1. These results do not exclude the causality of HTLV-I as a germen associated to CHISPA; however, other causes (e.g., toxic, immunosuppressors) must be considered as participating in the multistep neurodegeneration observed in CHISPA throughout the world.

HTLV-negative and HTLV type I-positive tropical spastic paraparesis in northeastern Brazil

A type-specific serological survey among 1042 random nonneurological outpatients in two cities in the state of Ceara (northeastern Brazil) shows a low prevalence of HTLV-I (0.34% in Fortaleza; 0.44% in Crato) and of HTLV-II (0.34% in Fortaleza; 0% in Crato). Among 62 chronic myelopathic patients seen in Fortaleza 27 patients were found with clinical features of tropical spastic paraparesis (TSP); 10 of 27 were found HTLV-I seropositive (37%; 95% confidence limits, 19-58%). Proviral genome detection by polymerase chain reaction in 5 seropositive and 12 seronegative patients confirmed the serological findings. This excludes HTLV-I or -II infection as a cause in the seronegative TSP patients. The HTLV-positive and -negative patients did not differ clinically and by history, except that seropositives had a longer mean disease duration, a female predominance, and a higher proportion of white Caucasians. In this population with low HTLV-I and HTLV-II prevalences, HTLV-negative TSP is at least as frequent as the HTLV-I-associated TSP.

Habitat, density and group size of primates in a Brazilian tropical forest

Habitats, population densities and group sizes of 5 primate species (Callithrix flaviceps, Callicebus personatus personatus, Cebus apella nigritus, Alouatta fusca clamitans, and Brachyteles arachnoides) were estimated, using the method of repeated transect sampling, in an area of montane pluvial forest in eastern Brazil (Atlantic forest). A. fusca and C. apella had the highest densities in terms of groups and individuals per square kilometer, respectively, while B. arachnoides was least abundant. The highest primate densities were observed in areas of secondary vegetation. Both group sizes and population densities for the 5 species were generally lower at the Reserva Biologica Augusto Ruschi than those reported in other areas of Atlantic forest. Hunting pressure and the different carrying capacity of the habitat are suggested as possible causes for the low number of sightings registered for these species.

Envelope cross-reactivity between human immunodeficiency virus types 1 and 2 detected by different serological methods: correlation between cross-neutralization and reactivity against the main neutralizing site

A total of 70 human immunodeficiency virus type 1 (HIV-1) and 42 HIV-2 antibody-positive serum samples, collected from groups of individuals in which only one type of HIV prevails, were tested for cross-reactivity against HIV-2 and HIV-1 proteins by Western blot (WB) (immunoblot), radioimmunoprecipitation assay (RIPA), neutralization analysis, and enzyme-linked immunosorbent assay with as antigen synthetic peptides representing selected parts of the envelope (env) glycoproteins. Cross-reactions against the env glycoproteins were observed by WB in 10% (7 of 70) and by RIPA in 40% (28 of 70) of the HIV-1 antibody-positive serum samples and by WB in 29% (12 of 42) and by RIPA in 48% (20 of 42) of the HIV-2 antibody-positive serum samples. Testing by enzyme-linked immunosorbent assay against a 36-amino-acid peptide (Cys-301-Cys-336) of the external glycoprotein of strain HTLV-IIIB of HIV-1 (HIV-1HTLV-IIIB) (known to represent a dominating, linear neutralizing site) showed type-specific reactions in 67% (38 of 57) of HIV-1 antibody-positive serum samples. Type-specific reactions against a homologous 35-amino-acid peptide of strain SBL-6669 of HIV-2 (HIV-2SBL-6669) were found in 75% (30 of 40) of HIV-2 antibody-positive serum samples, and these reactions were correlated to neutralization against HIV-2SBL-6669. Cross-reactions against these peptides were seen in 23% (13 of 57) and 33% (13 of 40) of the HIV-1 and HIV-2 antibody-positive serum samples, respectively. These cross-reactions were correlated to cross-neutralization against HIV-1HTLV-IIIB and HIV-2SBL-6669. Cross-neutralization against one heterotypic virus strain was demonstrated in 16% (9 of 57) of HIV-1 antibody-positive serum samples and in 22% (5 of 22) of HIV-2 antibody-positive serum samples, but no correlation was found between cross-neutralization and env cross-reactivity in WB or RIPA.

Cross-neutralizing antibodies against HIV-1 (HTLV-IIIB and HTLV-IIIRF) and HIV-2 (SBL-6669 and a new isolate SBL-K135)

A total of 57 HIV-1 antibody-positive sera and 43 HIV-2 antibody-positive sera were all tested for neutralizing capacity against two HIV-1 isolates (HTLV-IIIB and HTLV-IIIRF) and two HIV-2 isolates (SBL-6669 and SBL-K135). SBL-K135 is a new HIV-2 isolate obtained from a patient with clinical AIDS from Guinea-Bissau. Among the HIV-1--positive sera, 84% neutralized any of the HIV-1 isolates, 67% neutralized both HIV-1 isolates, and 35% neutralized any of the HIV-2 isolates. Among the HIV-2--positive sera, 91% neutralized any of the HIV-2 isolates, 67% neutralized both HIV-2 isolates, and 37% neutralized any of the HIV-1 isolates. Thus, neutralizing antibodies in HIV-1-- and HIV-2--positive sera can be cross-reacting, type-specific, or strain-specific. The cross-neutralizing titers were lower than the neutralizing titers against the type-specific viral isolates. The presence of cross-neutralizing antibodies was related to the presence of neutralizing antibodies against both type-specific isolates.

Tropical spastic paraparesis in Northeastern Brazil

Ten possible cases of tropical spastic paraparesis (TSP) in Northeastern Brazil (Ceará) are presented. They show the typical symptoms and signs of TSP consisting of weakness of the lower limbs, spastic gait, hyperreflexia, bladder dysfunction and variable signs of posterior columns impairment. The laboratory examinations excluded other compressive, infective, degenerative or demyelinating lesions of their spinal cord. Our patients age ranged from 21 to 59 years, all were of black origin and all were of lower social class. There was a slight preponderance of females. An etiological implication of a retrovirus (HTLV-I) has been shown for TSP, but for lack of technical conditions we could not determine it in our patients, and that stands as our subsequent step in those and further cases.

Site-directed enzyme-linked immunosorbent assay with a synthetic simian immunodeficiency virus SIVmac peptide identifying antibodies against the HIV-2 transmembrane glycoprotein

A 23-amino-acid-long peptide (AIEKYLEDQAQLNAWGCAFRQVC) representing the transmembranous protein gp32 in SIVmac was used in site-directed enzyme-linked immunosorbent assay (ELISA) for detection of HIV-2-specific antibodies in 567 sera from Bissau, Guinea Bissau. Ninety out of the 567 sera were identified to contain HIV-2 antibodies by whole antigen ELISA and Western blot assays. The peptide ELISA correctly identified 89 out of these 90 seropositives (sensitivity 98.9%). Three sera falsely interpreted to be positive were encountered (specificity 99.4%). The HIV-2 peptide was also used for testing of 93 HIV-1-positive Swedish sera. None of these sera reacted. Site-directed serology employing synthetic peptides should be considered for application as a screening assay.

Enzyme immunoassays for the demonstration of antibodies to HIV-2SBL-6669 and HTLV-IV (SIVmac)

Enzyme-linked immunosorbent assays (ELISA) were developed for the demonstration of antibodies to HIV-2 using disrupted virions of the SBL-6669 isolate of HIV-2 and the so-called human T-lymphotropic virus type IV (HTLV-IV), recently found to be identical with the simian immunodeficiency virus (SIVmac), as antigens. Three hundred sera from West African subjects, attending an outward clinic in Bissau for examination of suspected tuberculosis, were tested by these two assays as well as by a commercially available anti-HIV-2 ELISA (ELAVIA II). Fifty of these sera were positive in all three ELISAs as well as in Western blot tests against HTLV-IV. Thirty-eight of these positive sera were also tested by an anti-HIV-2 Western blot kit (LAV-Blot II) with positive results. The ELISAs based on SBL-6669 and HTLV-IV antigens had a specificity of 99.6% (one false positive among 250 negative sera) whereas the specificity of ELAVIA II was 94.6% using the recommended cut-off value and 98.4% using a higher cut-off value. Another 58 sera from West African patients, clinically suspected of having AIDS or HIV-related disease, were tested for HIV-2/HTLV-IV antibodies by Western blot and by ELISA against SBL-6669 and HTLV-IV antigens; all of the 30 sera which were positive by Western blot were found to be positive in both ELISAs.(ABSTRACT TRUNCATED AT 250 WORDS)

A hypothetical immunemediated unifying mechanism for the Holmes-Adie syndrome

The Holmes-Adie syndrome consists of pupillotonia, arreflexia and autonomic dysfunction. Some explanations for these different symptoms have been attempted, centred upon neuropathological and electrophysiological findings. A hypothetical immunemediated mechanism, as in the Guillain Barré syndrome, is presented in this paper for explaining the three chief symptoms of the syndrome.

Possibility of reducing the luteolytic dose of cloprostenol in cyclic dairy cows

The administration of cloprostenol by intravulvosubmucous (i.v.s.m.) injection at 1 2 and 1 4 of the dose usually given by intramuscular (i.m.) injection, was tested in dairy cows for luteolysis and estrus synchronization. The i.m. injection was used in ten adult cows at the usual dose of 500 mug/animal. Eleven adult cows and 11 heifers were treated i.v.s.m. with a dose equivalent to 250 mug/animal and 125 mug/animal, respectively. Two injections of cloprostenol were administered 11 days apart to the cows not detected in oestrus after a single injection. Forty-three out of the total 46 animals were detected to be in dioestrus at the time of at least one of the injections, as reflected by the plasma progesterone concentrations at the time of treatments. Three out of the 43 animals injected during dioestrus were refractory to the luteolytic effect of cloprostenol; this appeared to be independent of the dosage and the route of administration (refractory cows were: one adult cow treated i.m. and two treated i.v.s.m. with 125 mug of cloprostenol). The mean time interval from injection to the onset of heat was 82.8 hours with a confidence limit for 95% of probability between 67.9 hours and 92.7 hours. The difference between treatments is not significant. The results suggest that in heifers and adult cows cloprostenol can be given i.v.s.m. route at a reduced dose of 1 4 of the usual 500 mug i.m. dosage without affecting the luteolytic effect of the drug or fertility.

[A case of bilateral tonic pupil (Holmes-Adie syndrome)]

The authors present a case of bilateral tonic pupil and discuss clinical and physiopathological aspects of this syndrome. They discuss some elements necessary for the understanding of the etiopathogenesis of the disease.

Immunopathology of experimental schistosome (S. Mansoni) egg granulomas in mice--possible defence mechanisms mediated by local immune complexes

A ten month experimental S. Mansoni infection was followed in mice by studying schistosome egg granulomatous inflammation, antigen and immunoglobulins deposits in the granulomata and the circulating antibodies. During the experimental infection it was demonstrated that while the granulomatous reaction matures there is a progressive restriction of the antigens to the miracidia. Furthermore, immunoglobulins, particularly IgG and C3 deposits were demonstrated in the granulomata. Our data support the concept that schistosome egg granuloma is a hypersensitivity high turnover granuloma that is particularly efficient in walling off the antigen. Whereas the granuloma is built up largely by a cell mediated immune reaction, antibody deposits are also found, probably functioning as a local humoral antibody barrier which allows a slow and progressive neutralisation of the antigens. Viewed as a whole, experimental schistosome egg granuloma might be considered as a mixed, chiefly cell but also humoral antibody mediated immune reaction.