Serological, epidemiological and molecular aspects of hepatitis C virus infection in a population from Londrina, PR, Brazil, 2001-2002

Serological, epidemiological and molecular aspects of hepatitis C virus (HCV) infection were evaluated in 183 subjects from Londrina, Paraná, Brazil, and adjacent areas. Serum samples which tested anti-HCV positive by microparticle enzyme immunoassay (MEIA) obtained from eight patients with chronic hepatitis C, 48 blood donors, and 127 patients infected with the human immunodeficiency virus (HIV) were submitted to another enzyme immunoassay (ELISA) and to the polymerase chain reaction (PCR). About 78.7% of samples were also reactive by ELISA, with the greater proportion (70.8%) of discordant results verified among blood donors. A similar finding was observed for HCV-RNA detection by PCR, with 111/165 (67.3%) positive samples, with higher rates among HIV-positive subjects and patients with chronic hepatitis than among blood donors. Sixty-one PCR-positive samples were submitted to HCV genotyping, with 77.1, 21.3 and 1.6% of the samples identified as types 1, 3 and 2, respectively. Finally, analysis of some risk factors associated with HCV infection showed that intravenous drug use was the most common risk factor among HIV/HCV co-infected patients, while blood transfusion was the most important risk factor in the group without HIV infection. The present study contributed to the knowledge regarding risk factors associated with HCV infection and the distribution of HCV genotypes in the population evaluated.     

Inzidenz des Postmyelographiesyndroms (PMS) und postmyelographischer Beschwerden nach lumbaler Punktion mit der bleistiftförmigen Nadel nach Sprotte im Vergleich zur Nadel nach Quincke

Zusammenfassung Die Myelographie zusammen mit der Postmyelographie-CT ist eine wichtige Untersuchungsmethode in der pr?operativen Diagnostik. Bei nahezu der H?lfte der Patienten k?nnen postpunktionelle Beschwerden bis zu einem Postmyelographie-Syndrom (PMS) auftreten. Pathophysiologisch kann dies durch ein Punktionsleck mit anschlie?endem Liquorverlust erkl?rt werden. Ziel der Studie ist es, den Einflu? zweier Nadeltypen (21 G Nadel nach Sprotte vs 22 G Nadel nach Quincke) auf die Inzidenz postpunktioneller Beschwerden zu überprüfen. In einer prospektiven randomisierten Studie wurden bei 412 Patienten nach lumbaler intrathekaler Kontrastmittelapplikation (Iotrolan, Fa. Schering) die H?ufigkeit des PMS und postpunktioneller Nebenwirkungen in Abh?ngigkeit vom verwendeten Nadeltyp untersucht. Die H?ufigkeit postpunktioneller Beschwerden nach lumbaler Punktion mit der bleistiftf?rmigen Nadel nach Sprotte im Vergleich zur geschliffenen Nadel nach Quincke lag deutlich niedriger (Kopfschmerzen: 6,3 % vs 18,9 %, p < 0,0001; Kofschmerzen für mindestens drei Tage: 0,5 % vs 7,8 %, p < 0,0001; Kopfschmerzen für mindestens 5 Tage: 0 % vs 2,4 %, p = 0,0305; übelkeit: 0 % vs 4,9 %, p = 0,0009; Erbrechen: 0 % vs 4,9 %, p = 0,0009; Schwindel: 0 % vs 3,4 %, p = 0,0074; Nackensteife: 0 % vs 3,4 %, p = 0,0074; PMS: 0 % vs 3,4 %, p = 0,0074). Die Temperatur des Kontrastmittels beeinflu?te die postmyelographischen Beschwerden nicht. Schlu?folgerung: Die Inzidenz des PMS und postpunktioneller Beschwerden kann durch den Einsatz einer „atraumatischen“Nadel nach Sprotte deutlich gesenkt werden. Eingegangen am 22. August 1996 Angenommen am 30. August 1996     

Comparison of cerebral perfusion reserve and collateral circulation in patients with internal carotid artery disease

Summary The cerebral hemodynamics in patients with carotid disease is influenced by a network of extra- and intracranial collaterals. The purpose of this study was to compare the findings of regional cerebral perfusion reserve (rCPR) with angiographically proven collateral circulation. In 41 patients (28 men, 13 women, age 63 ± 10 years) with angiographically proven carotid stenoses or occlusions (30 stenoses, 11 occlusions) 24 ^{99 m}Tc-HMPAO-SPECT and 25 dynamic Xe-CT investigations were conducted, both before and after acetazolamide stimulation. rCPR was quantified as the ratio (1) of the absolute rCBF values obtained by Xe-CT and (2) of the count density measured by HMPAO-SPECT of the acetazolamide administration. A rCPR of less than 95 % in a vascular territory was classified as compromised rCPR. A recent CT examination was available in all cases. According to the angiographic findings the patients could be classified into (1) group A (n = 9) with residual carotid perfusion, (2) Group B (n = 8) with collateralization via the circle of Willis, and (3) group C (n = 24) with leptomeningeal or ophthalmic artery collateral circulation. The rCPR values were significantly different in groups B and C with both methods, Xe-CT (P = 0.0035) and HMPAO-SPECT (P = 0.0014). rCPR was decreased in 13/14 group C patients investigated with Xe-CT and in 11/14 examined with HMPAO-SPECT. All patients in group B showed normal rCPR according to Xe-CT and HMPAO-SPECT. In group A, six of seven revealed decreased rCPR on Xe-CT, while rCPR values were normal in all four group A-patients examined with HMPAO-SPECT. The cerebral hemodynamics depend on a collateralization network and not only on the degree of internal carotid artery (ICA) stenosis. A decreased CPR in a vascular territory ipsilateral to an ICA stenosis or occlusion correlates strongly with the angiographic finding of leptomeningeal or ophthalmic artery collateral circulation.      

Fate and effects of the insecticide Dursban® 4E in indoor Elodea-dominated and macrophyte-free freshwater model ecosystems: II. Secondary effects on community structure

Secondary effects of a single dose of the insecticide Dursban^® 4E (active ingredient chlorpyrifos) were studied in indoor experimental freshwater ecosystems intended to mimic drainage ditches. Two experiments were performed, one in which all model ecosystems were dominated by the macrophyte Elodea nuttallii, and one using systems devoid of macrophytes.In the Elodea-dominated and macrophyte-free model ecosystems, populations of primary producers, herbivores, carnivores and detritivores were indirectly affected via the loss of populations of Arthropoda as a direct result of insecticide application. However, the taxa in which secondary effects were observed differed considerably between these two types of model ecosystem. In macrophyte-dominated systems secondary effects were observed on populations of periphytic algae, the macrophyte Elodea nuttallii, the gastropod Bithynia tentaculata, Turbellaria, and sediment dwelling Oligochaeta. In open water systems it were populations of phytoplankton, the rotators Polyarthra and Asplanchna, bivalves (Sphaeriidae), Hirudinea, sediment dwelling Oligochaeta, and that of the isopod Proasellus coxalis in which secondary effects were observed. In aquatic ecosystems the presence or absence of a well-developed macrophyte vegetation may be a very important characteristic that determines the nature and route of secondary effects induced by pesticides. The differences in secondary effects observed between Elodea-dominated and macrophyte-free model ecosystems indicate that the system's structure and trophic dynamics should be taken into account when predicting ecological effects.     

Dysembryoplastischer neuroepithelialer Tumor (DNT) Neuroradiologische Befundmuster

Zusammenfassung Die Gruppe der dysembryoplastischen neuroepithelialen Tumore (DNT) wurde erstmals von Daumas-Duport et al. 1988 beschrieben und 1993 als eigenst?ndige Tumorentit?t in die revidierte Fassung der WHO der Klassifikation der Hirntumoren aufgenommen. Ziel der vorliegenden Arbeit ist, die neuroradiologischen CT- und MRT-Charakteristika von DNT aufzuarbeiten. Fünf Patienten im Alter von 11–61 Jahren (3 Frauen, 2 M?nner) wurden pr?chirurgisch neuroradiologisch untersucht (5 CT-, 4 MRT- und 2 DSA-Studien). Klinisch litten 4 Patienten unter epileptischen Anf?llen und 1 Patientin unter okzipital betonten Kopfschmerzen. In 2 F?llen wurde der Tumor mikrochirurgisch komplett und in 2 F?llen nach vorausgegangener stereotaktischer Biopsie partiell reseziert. Bei 1 Fall wurde nur eine stereotaktische Biopsie durchgeführt. Alle DNT waren kortikal lokalisiert: 2 frontobasal medial im Gyrus rectus, 2 temporobasal im Gyrus occipitotemporalis lateralis und einer infratentoriell im Lobus caudalis cerebelli. Sie lie?en sich scharf vom umgebenden Hirngewebe abgrenzen und zeigten im MRT einen multinodul?ren Tumoraufbau. Die kortikale Lokalisation lie? sich am besten im MRT erkennen, insbesondere auf koronaren und sagittalen Schnitten. Im CT stellten sie sich als hypodense L?sion dar. Im MRT zeigten sie T2-gewichtet eine Signalerh?hung, T1-gewichtet ein erniedrigtes Signal und in der Protonenwichtung einen hyperintensen Rand mit kleinen, geringgradig hyperintensen Zysten. Zwei DNT nahmen Kontrastmittel auf, w?hrend bei 3 keine Kontrastmittelaffinit?t nachweisbar war. Der infratentorielle DNT lag in unmittelbarer Nachbarschaft zu einem Defekt der Tabula interna, in welchen er sich ausdehnte. Die 2 angiographisch untersuchten DNT zeigten keine Tumorneovaskularisation. Ein umschriebener, im CT hypodenser, scharf begrenzter Tumor mit einer multinodul?ren Struktur im MRT, kortikal lokalisiert, ohne Raumforderungszeichen, verbunden mit der klinischen Symptomatik einer Epilepsie ist stets verd?chtig auf das Vorliegen eines DNT. Wie unsere Ergebnisse zeigen, k?nnen DNT auch infratentoriell auftreten. Eingegangen am 22. August 1996 Angenommen am 26. August 1996     

Loss of HIV-specific memory B-cells as a potential mechanism for the dysfunction of the humoral immune response against HIV

A central, yet unresolved issue in the pathogenesis of HIV disease is the mechanism of antibody perturbation. In this study, HIV-specific memory B-cells were quantified in groups of infected subjects and compared with memory responses to other antigens and antibody titers. HIV-specific memory B-cell responses were vigorous in individuals with CD4⁺ T-cell counts > 350/μl and weak or undetectable in subjects with CD4⁺ T-cell numbers < 200/μl. Memory B-cell loss was permanent, because antiretroviral therapy failed to restore HIV-specific memory responses while influenza- and tetanus toxoid-specific memory B-cells remained unaffected or recovered. Antibody titers to Gag strongly correlated with memory B-cell frequencies. In contrast, Env-specific antibodies were maintained in advanced disease despite low or undetectable levels of memory B-cells. These results provide a potential mechanism by which destruction of HIV-specific CD4⁺ T-cells affects the humoral immune response against HIV and compromises the ability to maintain an effective antibody response.