Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering.

Osteoporotic-related fractures are among the leading causes of chronic disease morbidity in Europe and in the US. While a significant percentage of fractures can be repaired naturally, in delayed-union and non-union fractures surgical intervention is necessary for proper bone regeneration. Given the current lack of optimized clinical techniques to adequately address this issue, bone tissue engineering (BTE) strategies focusing on the development of scaffolds for temporarily replacing damaged bone and supporting its regeneration process have been gaining interest. The piezoelectric properties of bone, which have an important role in tissue homeostasis and regeneration, have been frequently neglected in the design of BTE scaffolds. Therefore, in this study, we developed novel hydroxyapatite (HAp)-filled osteoinductive and piezoelectric poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TrFE) nanofibers via electrospinning capable of replicating the tissue's fibrous extracellular matrix (ECM) composition and native piezoelectric properties. The developed PVDF-TrFE/HAp nanofibers had biomimetic collagen fibril-like diameters, as well as enhanced piezoelectric and surface properties, which translated into a better capacity to assist the mineralization process and cell proliferation. The biological cues provided by the HAp nanoparticles enhanced the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (MSCs) as observed by the increased ALP activity, cell-secreted calcium deposition and osteogenic gene expression levels observed for the HAp-containing fibers. Overall, our findings describe the potential of combining PVDF-TrFE and HAp for developing electroactive and osteoinductive nanofibers capable of supporting bone tissue regeneration.

Novel Electroactive Mineralized Polyacrylonitrile/PEDOT:PSS Electrospun Nanofibers for Bone Repair Applications.

Bone defect repair remains a critical challenge in current orthopedic clinical practice, as the available therapeutic strategies only offer suboptimal outcomes. Therefore, bone tissue engineering (BTE) approaches, involving the development of biomimetic implantable scaffolds combined with osteoprogenitor cells and native-like physical stimuli, are gaining widespread interest. Electrical stimulation (ES)-based therapies have been found to actively promote bone growth and osteogenesis in both in vivo and in vitro settings. Thus, the combination of electroactive scaffolds comprising conductive biomaterials and ES holds significant promise in improving the effectiveness of BTE for clinical applications. The aim of this study was to develop electroconductive polyacrylonitrile/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PAN/PEDOT:PSS) nanofibers via electrospinning, which are capable of emulating the native tissue's fibrous extracellular matrix (ECM) and providing a platform for the delivery of exogenous ES. The resulting nanofibers were successfully functionalized with apatite-like structures to mimic the inorganic phase of the bone ECM. The conductive electrospun scaffolds presented nanoscale fiber diameters akin to those of collagen fibrils and displayed bone-like conductivity. PEDOT:PSS incorporation was shown to significantly promote scaffold mineralization in vitro. The mineralized electroconductive nanofibers demonstrated improved biological performance as observed by the significantly enhanced proliferation of both human osteoblast-like MG-63 cells and human bone marrow-derived mesenchymal stem/stromal cells (hBM-MSCs). Moreover, mineralized PAN/PEDOT:PSS nanofibers up-regulated bone marker genes expression levels of hBM-MSCs undergoing osteogenic differentiation, highlighting their potential as electroactive biomimetic BTE scaffolds for innovative bone defect repair strategies.

Piezoelectric Electrospun Fibrous Scaffolds for Bone, Articular Cartilage and Osteochondral Tissue Engineering.

Osteochondral tissue (OCT) related diseases, particularly osteoarthritis, number among the most prevalent in the adult population worldwide. However, no satisfactory clinical treatments have been developed to date to resolve this unmet medical issue. Osteochondral tissue engineering (OCTE) strategies involving the fabrication of OCT-mimicking scaffold structures capable of replacing damaged tissue and promoting its regeneration are currently under development. While the piezoelectric properties of the OCT have been extensively reported in different studies, they keep being neglected in the design of novel OCT scaffolds, which focus primarily on the tissue's structural and mechanical properties. Given the promising potential of piezoelectric electrospun scaffolds capable of both recapitulating the piezoelectric nature of the tissue's fibrous ECM and of providing a platform for electrical and mechanical stimulation to promote the regeneration of damaged OCT, the present review aims to examine the current state of the art of these electroactive smart scaffolds in OCTE strategies. A summary of the piezoelectric properties of the different regions of the OCT and an overview of the main piezoelectric biomaterials applied in OCTE applications are presented. Some recent examples of piezoelectric electrospun scaffolds developed for potentially replacing damaged OCT as well as for the bone or articular cartilage segments of this interfacial tissue are summarized. Finally, the current challenges and future perspectives concerning the use of piezoelectric electrospun scaffolds in OCT regeneration are discussed.

Non-invasive positive airway pressure therapy for improving erectile dysfunction in men with obstructive sleep apnoea.

BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is associated with several chronic diseases, including erectile dysfunction (ED). The association of OSAS and ED is far more common than might be found by chance; the treatment of OSAS with non-invasive positive airway pressure therapy is associated with improvement of respiratory symptoms, and may contribute to the improvement of associated conditions, such as ED. OBJECTIVES: To assess the effectiveness and acceptability of non-invasive positive airway pressure therapy for improving erectile dysfunction in OSAS. SEARCH METHODS: We identified studies from the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, AMED EBSCO, and LILACS, the US National Institutes of Health ongoing trials register ClinicalTrials.gov, and the World Health Organisation international clinical trials registry platform to 14 June 2021, with no restriction on date, language, or status of publication. We checked the reference lists of all primary studies, and review articles for additional references, and relevant manufacturers' websites for study information. We also searched specific conference proceedings for the British Association of Urological Surgeons; the European Association of Urology; and the American Urological Association to 14 June 2021. SELECTION CRITERIA: We considered randomised controlled trials (RCTs) with a parallel or cross-over design, or cluster-RCTs, which included men aged 18 years or older, with OSAS and ED. We considered RCTs comparing any non-invasive positive airway pressure therapy (such as continuous positive airways pressure (CPAP), bilevel positive airway pressure (BiPAP), variable positive airway pressure (VPAP), or similar devices) versus sham, no treatment, waiting list, or pharmacological treatment for ED. The primary outcomes were remission of ED and serious adverse events; secondary outcome were sex-related quality of life, health-related quality of life, and minor adverse events. DATA COLLECTION AND ANALYSIS: Two review authors independently conducted study selection, data extraction, and risk of bias assessment. A third review author solved any disagreement. We used the Cochrane RoB 1 tool to assess the risk of bias of the included RCTs. We used the GRADE approach to assess the certainty of the body of evidence. To measure the treatment effect on dichotomous outcomes, we used the risk ratio (RR); for continuous outcomes, we used the mean difference (MD). We calculated 95% confidence intervals (CI) for these measures. When possible (data availability and homogeneous studies), we used a random-effect model to pool data with a meta-analysis. MAIN RESULTS: We included six RCTs (all assessing CPAP as the non-invasive positive airway pressure therapy device), with a total of 315 men with OSAS and ED. All RCTs presented some important risk of bias related to selection, performance, assessment, or reporting bias. None of included RCTs assessed the ED remission rate, and we used the provided ED mean scores as a proxy. CPAP versus no CPAP There is uncertainty about the effect of CPAP on mean ED scores after 4 weeks, using the International index of erectile function (IIEF-5, higher = better; MD 7.50, 95% CI 4.05 to 10.95; 1 RCT; 27 participants; very low-certainty evidence), and after 12 weeks (IIEF-ED, ED domain; MD 2.50, 95% CI -1.10 to 6.10; 1 RCT; 57 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). There is uncertainty about the effect of CPAP on sex-related quality of life after 12 weeks, using the Self-esteem and relationship test (SEAR, higher = better; MD 1.00, 95% CI -8.09 to 10.09; 1 RCT; 57 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision); no serious adverse events were reported after 4 weeks (1 RCT; 27 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). CPAP versus sham CPAP One RCT assessed this comparison (61 participants), but we were unable to extract outcomes for this comparison due to the factorial design and reporting of this trial. CPAP versus sildenafil (phosphodiesterase type 5 inhibitors) Sildenafil may slightly improve erectile function at 12 weeks when compared to CPAP, measured with the IIEF-ED (MD -4.78, 95% CI -6.98 to -2.58; 3 RCTs; 152 participants; I² = 59%; low-certainty evidence, downgraded due to methodological limitations). There is uncertainty about the effect of CPAP on sex-related quality of life after 12 weeks, measured with the Erectile Dysfunction Inventory of Treatment Satisfaction questionnaire (EDITS, higher = better; MD -1.24, 95% CI -1.80 to -0.67; 2 RCTs; 122 participants; I² = 0%; very low-certainty evidence, downgraded due to methodological limitations). No serious adverse events were reported for either group (2 RCTs; 70 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). There is uncertainty about the effects of CPAP when compared to sildenafil for the incidence of minor adverse events (RR 1.33, 95% CI 0.34 to 5.21; 1 RCT; 40 participants; very low-certainty evidence, downgraded due to methodological limitations and imprecision). The confidence interval was wide and neither a significant increase nor reduction in the risk of minor adverse events can be ruled out with the use of CPAP (4/20 men complained of nasal dryness in the CPAP group, and 3/20 men complained of transient flushing and mild headache in the sildenafil group). AUTHORS' CONCLUSIONS: When compared with no CPAP, we are uncertain about the effectiveness and acceptability of CPAP for improving erectile dysfunction in men with obstructive sleep apnoea. When compared with sildenafil, there is some evidence that sildenafil may slightly improve erectile function at 12 weeks.

Synergy between 3D-extruded electroconductive scaffolds and electrical stimulation to improve bone tissue engineering strategies.

In this work, we propose a simple, reliable, and versatile strategy to create 3D electroconductive scaffolds suitable for bone tissue engineering (TE) applications with electrical stimulation (ES). The proposed scaffolds are made of 3D-extruded poly(ε-caprolactone) (PCL), subjected to alkaline treatment, and of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), anchored to PCL with one of two different crosslinkers: (3-glycidyloxypropyl)trimethoxysilane (GOPS) and divinyl sulfone (DVS). Both cross-linkers allowed the formation of a homogenous and continuous coating of PEDOT:PSS to PCL. We show that these PEDOT:PSS coatings are electroconductive (11.3-20.1 S cm-1), stable (up to 21 days in saline solution), and allow the immobilization of gelatin (Gel) to further improve bioactivity. In vitro mineralization of the corresponding 3D conductive scaffolds was greatly enhanced (GOPS(NaOH)-Gel - 3.1 fold, DVS(NaOH)-Gel - 2.0 fold) and cell colonization and proliferation were the highest for the DVS(NaOH)-Gel scaffold. In silico modelling of ES application in DVS(NaOH)-Gel scaffolds indicates that the electrical field distribution is homogeneous, which reduces the probability of formation of faradaic products. Osteogenic differentiation of human bone marrow derived mesenchymal stem/stromal cells (hBM-MSCs) was performed under ES. Importantly, our results clearly demonstrated a synergistic effect of scaffold electroconductivity and ES on the enhancement of MSC osteogenic differentiation, particularly on cell-secreted calcium deposition and the upregulation of osteogenic gene markers such as COL I, OC and CACNA1C. These scaffolds hold promise for future clinical applications, including manufacturing of personalized bone TE grafts for transplantation with enhanced maturation/functionality or bioelectronic devices.

Production of Blended Poly(acrylonitrile): Poly(ethylenedioxythiophene):Poly(styrene sulfonate) Electrospun Fibers for Neural Applications.

This study describes, for the first time, the successful incorporation of poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) in Poly(acrylonitrile) (PAN) fibers. While electroconductive PEDOT:PSS is extremely challenging to electrospun into fibers. Therefore, PAN, a polymer easy to electrospun, was chosen as a carrier due to its biocompatibility and tunable chemical stability when cross-linked, particularly using strong acids. PAN:PEDOT:PSS blends, prepared from PEDOT:PSS Clevios PH1000, were electrospun into fibers (PH1000) with a diameter of 515 ± 120 nm, which after being thermally annealed (PH1000 24H) and treated with heated sulfuric acid (PH1000 H2SO4), resulted in fibers with diameters of 437 ± 109 and 940 ± 210 nm, respectively. The fibers obtained over the stepwise process were characterized through infra-red/Raman spectroscopy and cyclic voltammetry. The final fiber meshes showed enhanced electroconductivity (3.2 × 10-3 S cm-1, four-points-assay). Fiber meshes biocompatibility was evaluated using fibroblasts and neural stem cells (NSCs) following, respectively, the ISO10993 guidelines and standard adhesion/proliferation assay. NSCs cultured on PH1000 H2SO4 fibers presented normal morphology and high proliferation rates (0.37 day-1 vs. 0.16 day-1 for culture plate), indicating high biocompatibility for NSCs. Still, the low initial NSC adhesion of 7% calls for improving seeding methodologies. PAN:PEDOT:PSS fibers, here successful produced for the first time, have potential applications in neural tissue engineering and soft electronics.

Electrically Conductive Hydrogels for Articular Cartilage Tissue Engineering.

Articular cartilage is a highly specialized tissue found in diarthrodial joints, which is crucial for healthy articular motion. Despite its importance, articular cartilage has limited regenerative capacities, and the degeneration of this tissue is a leading cause of disability worldwide, with hundreds of millions of people affected. As current treatment options for cartilage degeneration remain ineffective, tissue engineering has emerged as an exciting approach to create cartilage substitutes. In particular, hydrogels seem to be suitable candidates for this purpose due to their biocompatibility and high customizability, being able to be tailored to fit the biophysical properties of native cartilage. Furthermore, these hydrogel matrices can be combined with conductive materials in order to simulate the natural electrochemical properties of articular cartilage. In this review, we highlight the most common conductive materials combined with hydrogels and their diverse applications, and then present the current state of research on the development of electrically conductive hydrogels for cartilage tissue engineering. Finally, the main challenges and future perspectives for the application of electrically conductive hydrogels on articular cartilage repair strategies are also discussed.

Diode Laser Vaporization for Benign Prostate Hyperplasia: Outcome After 126 Procedures.

Purpose: Photoselective vaporization of the prostate (PVP) with a 940-nm diode laser is an option for treating symptoms caused by benign prostatic hyperplasia (BPH). Here, we present our experience using this technology. Methods: We prospectively evaluated 126 patients with lower urinary tract symptoms (LUTS) secondary to BPH who underwent PVP with a 940-nm diode laser from January 2011 to January 2014. The patients were assessed using the International Prostate Symptom Score (IPSS), quality of life (QoL) score, prostate-specific antigen (PSA) level, maximum urinary flow (Qmax) by uroflowmetry, postvoid residual volume, and prostate volume by ultrasound at baseline and 3, 6, 12, and 24 months after the procedure. Results: The average patient age was 68.8 ± 8.7 years (range 48-90 years), whereas the average preoperative parameters were as follows: IPSS, 26.1 ± 5.2; IPSS-QoL, 4.9 ± 0.8; Qmax, 4.5 ± 3.1 mL/s; prostate volume, 76.5 ± 35.5 mL; and PSA level, 3.9 ± 2.6 ng/mL. The average catheterization time was 24.7 ± 25.5 hours (range 3-120 hours), and the length of hospital stay was 22.4 ± 17.0 hours (range 8-144 hours). The mean follow-up duration was 17.9 months (range 1-36 months). All parameters showed significant improvement after 12 months. After 24 months, the IPSS (8.8 ± 5.4, p < 0.07), IPSS-QoL (1.6 ± 0.9, p < 0.13), Qmax (15.9 ± 7.3 mL/s, p < 0.11), and PSA level (1.2 ± 0.8 ng/mL, p < 0.11) were improved compared with the baseline, but the difference was not significant, probably due to the small number of patients evaluated in this period. No patients required a transfusion. Conclusions: The results suggest that PVP with a 940-nm diode laser is safe, effective, and durable for the treatment of LUTS secondary to BPH. The patients continue to be monitored for evaluation of the long-term results. A prospective randomized study would allow more solid conclusions regarding the technology to be reached.

Versatile magnetic carbon nanotubes for sampling and pre concentration of pesticides in environmental water.

This article describes a simple, efficient, and versatile magnetic carbon nanotubes (MCNT) method for sampling and pre-concentration of pesticides in environmental water samples. The multi-walled magnetic carbon nanotubes were obtained by chemical deposition vapor (CVD) process. The MCNTs structures are formed of hydrophobic and hydrophilic fractions that provide great dispersion at any water matrix allowing simultaneously a high efficiency of pesticides sorption. Following the extraction, analytes were desorbed with minor amounts of solvent and analyzed by gas chromatography coupled mass spectrometry (GC/MS). The parameters amount of MCNTs used to extraction, desorption time, and desorption temperature were optimized. The method showed good linearity with determination coefficients between 0.9040 and 0.9733. The limits of detection and quantification were ranged between 0.51 and 2.29µgL-1 and between 1.19 and 5.35µgL-1 respectively. The recovery ranged from 79.9% to 111.6%. The method was applied to the determination of fifteen multiclass pesticides in real samples of environmental water collected in Minas Gerais, Brazil.

Prevalência e fatores de risco para retinopatia diabética em pacientes diabéticos atendidos por demanda espontânea: um estudo transversal / Prevalence and risk factors of diabetic retinopathy in patients with diabetes seen by unscheduled demand: a cross-sectional study

RESUMO Objetivo: Estimar a prevalência da retinopatia diabética em pacientes diabéticos de uma capital brasileira e correlacioná-la com fatores de risco presentes na população estudada. Métodos: Estudo observacional transversal, realizado a partir do relatório de atendimentos prestados em mutirão ocorrido em 2018. O relatório foi preenchido pelos médicos oftalmologistas durante a campanha, com informações referentes a sexo do paciente, idade, classificação do diabetes mellitus, tempo de doença, uso de insulina, índice de massa corporal, hábitos de vida (tabagismo e atividade física) e história de hipertensão arterial sistêmica, dislipidemia, infarto agudo do miocárdio e acidente vascular cerebral, além de exame clínico oftalmológico realizado na ação. Resultados: Dentre os 219 participantes do estudo, a prevalência da retinopatia diabética foi de 31,96%. As variáveis que se apresentaram como fator de risco com significância estatística foram sexo masculino, idade de 51 a 70 anos, mais de 10 anos de diabetes mellitus, insulinoterapia, índice de massa corporal ≥40kg/m2 e história prévia de infarto agudo do miocárdio. Atividade física mostrou-se como fator protetor significativo. Conclusão: Estudos populacionais ao longo dos anos comprovaram a variabilidade geográfica na prevalência da retinopatia diabética justificada pela diferente exposição aos fatores de risco. Dentro de tal conjuntura, ressalta-se o quão fundamental é o conhecimento das características regionais, de modo a orientar as políticas de saúde pública, permitindo atuar com impacto na redução das estatísticas de cegueira evitável.

ABSTRACT Objective: To estimate the prevalence of diabetic retinopathy in patients with diabetes, from a Brazilian capital city, and to correlate with the risk factors present in the studied population. Methods: A cross-sectional observational study, based on the report of care provided by a campaign, in 2018. The report was filled out by ophthalmologists during the joint effort, with information on patient's gender, age, classification of diabetes mellitus, duration of illness, use of insulin, body mass index, lifestyle (smoking and physical activity), history of hypertension, dyslipidemia, myocardial infarction, stroke, and the clinical ophthalmic examination. Results: Among the 219 study participants, the prevalence of diabetic retinopathy was 31.96%. The variables considered risk factors with statistical significance were male sex, age 51-70 years, diabetes mellitus for over 10 years, insulin therapy, body mass index ≥40 kg/m2, and previous history of myocardial infarction. The physical activity proved to be a significant protective factor. Conclusion: Over the years, population studies have proven the geographical variability in prevalence of diabetic retinopathy justified by different exposure to risk factors. Therefore, knowledge of regional characteristics is crucial and emphasized in the text, since it can guide public health policies, aiming to have an impact on reduction of preventable blindness statistics.

Reduction in Renal Specimen After Laparoscopic Radical Nephrectomy: A Histopathologic Analysis.

Abstract Background and Purpose: There is no consensus on the most appropriate way to extract the kidney after laparoscopy. A previous study evaluated the reduction in total kidney volume and incision size (40%) after perfusion with a 5% hypertonic solution in a porcine model. The purpose of the current study was to compare the histopathologic renal tumor diagnosis before and after this perfusion. Furthermore, fluid drained from the renal vein was analyzed for the presence of neoplastic cells. Materials and Methods: After radical nephrectomy, specimens of 21 cases of renal tumors were studied. A small piece of the tumor was removed and fixed in formaldehyde. After that, 500 mL of a 5% NaCL solution was infused through the renal artery. The first 10 mL drained from the vein was collected and sent for cytologic study. The specimens and the fragment were analyzed. The parameters studied were histologic subtypes, Fuhrman grade, necrosis, and microvascular invasion. Results: Clear-cell renal carcinoma was found in 81% of the cases. Two cases of chromophobic renal carcinoma, one case of papillary tumor, and one case of oncocytoma were found. There were no differences in histologic subtypes, Fuhrman grade, necrosis, and microvascular invasion before and after perfusion in most of the cases. All cytologic analysis of drained liquid from the renal vein was negative for neoplastic cells. Conclusions: Renal perfusion with 5% NaCL solution after laparoscopic radical nephrectomy did not interfere with the histopathologic and cytologic characteristics of the kidney. In addition, all samples from the liquid drained from the renal vein were negative for neoplastic cells. These findings suggest that renal shrinkage with hypertonic saline after laparoscopic radical nephrectomy is feasible and might be useful for patients with kidney cancer. Validation of our results as well as their impact on clinical outcomes is warranted.

Pulmonary histoplasmosis simulating metastasis: two cases report and review of the literature / Histoplasmose pulmonar simulando metástases: relato de dois casos e revisão de literatura

Introduction and objectives: Systemic mycoses are of great importance in immunosuppression-associated conditions. Histoplasmosis can produce different symptoms that may simulate metastasis. We aim to demonstrate the importance of histopathological confirmation of lesions suggestive of metastases in patients with malignant neoplasm. Cases report: Two patients undergoing cancer treatment, whose chest computed tomography (CT) revealed pulmonary nodules, compatible with metastases. The lesions were biopsied, confirming histoplasmosis granuloma. Conclusion: In patients with cancer, clinical and radiological findings are not limited to metastatic dissemination of tumors, requiring histopathological confirmation of lesions suggestive of metastasis, excluding other diseases and preventing inappropriate treatment. .

Introdução e objetivos: Micoses sistêmicas assumem grande importância nas situações de imunodepressão. A histoplasmose pode produzir diversas manifestações clínicas, podendo simular metástases. Objetivamos demonstrar a importância da confirmação histopatológica de lesão sugestiva de metástase em portadores de neoplasia maligna. Relatos dos casos: Dois pacientes com neoplasias em tratamento, nos quais tomografias de tórax de controle revelaram nódulos pulmonares compatíveis com metástases. As lesões foram biopsiadas, confirmando-se granulomas por histoplasmose. Conclusão: Em portadores de malignidade, aspectos clinicorradiológicos não se limitam à disseminação das neoplasias, sendo necessária a confirmação histopatológica de lesões sugestivas de metástases, excluindo-se outras doenças e evitando-se tratamentos inadequados. .

Fome e prosperidade econômica na América / Hunger and economic prosperity in America

Uma análise crítica sobre a situaçao da pobreza e da fome no período de 1977 a 1986 foi feita por J. Larry Brow et alli, nos EUA. Os autores indicam que as causas subjacentes deste fenômeno repousam sobre o aumento da desigual distribuiçao da riqueza naquele país e do enfraquecimento dos programas federais de assistência aos pobres. Comentários de outros sugerem que as causas mais profundas deste fenômeno têm raízes estruturais

Determination and control of schistosomiasis

The subject of this conference reflects the scientific community's interest in seeking to understand the complex causal web whose various social, economic, and biological components interact in the production and reproduction of schistosomiasis and its control in relation to community participation. From the onset, the author stresses the impossibility of dealing separately with community participation, as if social components were just one more "weapon" in the arsenal for schistosomiasis control. This study begins with a brief historical review of the 71 years of control activities with this endemic disease, stressing the enormous efforts and huge expenditures in this field vis-à-vis the limited results, despite the extraordinary technological development of specific, classical control inputs such as new treatment drugs and molluscicides. The article then discusses the various strategies used in control programs, emphasizing ideological consistencies and contradictions. Interactions at the macro and micro levels are discussed, as are the determinants and risk factors involved in producing the disease's endemicity. Unequal occupation of space leaves the segregated portion of the population exposed to extremely favorable conditions for transmission of the disease. This raises the issue of how to control an endemic disease which is so closely linked to the way of life imposed on the population. The study challenges the classical control model and suggests an alternative model now undergoing medium-term investigation in the States of Espirito Santo, and Pernambuco, Brazil. The author concludes that we do not need new strategies, but a new control model, contrary to the prevailing classical model in both concept and practice. From the conceptual point of view, the new model mentioned above is different from others in that schistosomiasis control is seen from a social perspective stressing the population's accumulated knowledge in addition to the building of shared knowledge.

Mass migration of juvenile Biomphalaria glabrata snails bred under semi-natural conditions

For the development of studies on snail interspecific competition special in-door laboratory channels were built. In the all five channels seeded with adult specimens of Biomphalaria glabrata mass migration of juvenile snails outside the water was observed. Most of the migrant snails presented apertural lamellae. Data collected during the period of two years, showed the regression of the migration phenomenon and the disappearance of the lamellate snails.

Competitive displacement of Biomphalaria glabrata by B. straminea

Data on the interaction between populations of closely related species of Biomphalaria, B. glabrata and B. straminea, are presented in the current paper. Laboratory and field observations and experiments have shown that B. straminea has competitive advantages over B. glabrata.

O programa brasileiro de integração docente-assistencial no sistema de educação superior no campo da saúde

Resumo: Sintetizando os aspectos mais importantes do Programa de Integração Docente­ Assistencial desenvolvido em universidades brasileiras, o autor analisa a experiência obtida ao término de seu primeiro ano de execução e discute os principais obstáculos que a ela se opuseram. Propõe a mudança da atual estratégia do Programa, sugerindo a criação de cursos integrados de ciências da saúde, implantados como experimentos educacionais, em universidades recentes.

Summary: A program based on the integration between teaching and health services that is being carried out in seven brazilian universities, is analyzed in the current paper. The main obstacles to the development of the program are identified and discussed. Evaluation after the first year of the operational phase of the program indicates that its strategy should be changed. Accordingly, it is suggested that new integrated course should be implemented in new universities. These new courses should be looked upon as educational experiments.

The bioecology of snail vectors for schistosomiasis in Brazil

Aspectos ecológicos de duas espécies brasileiras de Biomphalaria, transmissoras da esquistossomose mansônica, säo discutidos no presente artigo B. glabrata e B. straminea tem sido intensamente estudadas no Brasil e em outros países desde a década de 50. Este artigo enfatiza três momentos que marcaram o desenvolvimento histórico de nosso conhecimento sobre a biologia destes caramujos: 1 o acervo antigo acumulado de estudos de laboratório e de campo; 2 o desenvolvimento de modelos ecológicos quantitativos; 3 o desenvolvimento de metodologia alternativa para o cultivo dos caramujos em condiçoes seminaturais.

Padräo epidemiológico da esquistossomose em comunidade de pequenos produtores rurais de Pernambuco, Brasil / Schistosomiasis epidemiological patterns in a community of small farmers in Pernambuco State, Brazil

Faz parte de um estudo mais ammplo que empregou abordagens epidemiológica e antropológica para procurar entender a produçäo e manutençäo da esquistossomose em pequena comunidade de área endêmica de Pernambuco. Realizamos um estudo de corte transversal para avaliaçäo dos fatores de risco para esquistossomose, associando variáveis sócio-econômicas, sanitárias e comportamentais (quantificáveis), com a prevalência e intensidade da infecçäo. Uma análise estatística univariada selecionou três variáveis (faixa etária, escolaridade e número de contatos), que mostraram associaçäo significativa com a positividade para S. mansoni. Os resultados da análise multivariada realizada a seguir permitiram a identificaçäo dos fatores causais e das variáveis de confundimento, entre aquelas anteriormente selecionadas. O diagnóstico epidemiológico quantitativo é discutido criticamente, com embasamento no estudo qualitativo etnográfico, quanto às condiçöes ambientais de risco (contaminaçäo, transmissäo) e práticas de risco (atividades econômicas e comportamentais).

Competitive interactions between species of fresh-water snails: I. Laboratory. IC. Comparative survival of Biomphalaria glabrata and B. Straminea kept out of water

Biomphalaria glabrata e B. straminea foram submetidas a um experimento para verificar a resistência comparativa de ambas as espécies à dessecaçäo. O estudo foi conduzido em condiçöes de laboratório em um tanque de cimento coberto, colocado fora do prédio. Os resultados mostraram que B. straminea é significantemente mais resistente à dessecaçäo que B. glabrata. Ao final da experiência, sob as condiçöes acima, a sobrevida foi a seguinte: 8,1% para B. glabrata e 18,4% para B. straminea