Quantification of mechanical properties in long-term in vivo used silicone catheter lines according to DIN 10555-3.

BACKGROUND: Totally implantable central venous access port devices are crucial for intravenous application of chemotherapeutics and long-term therapy for chronic disease. Common complications include thrombosis and device fracture related to altered material properties through exposure in situ. This study exhibits whether uniaxial tensile properties (DIN 10555-3) of in vivo used catheters prove inferior to unused catheters. MATERIAL AND METHODS: 5 unused, originally packed silicone catheters were cut into 6 segments of 50 mm: 3 segments each were cleaned via cleaning solution (n = 15) while 3 segments were left unattended (n = 15). Distal segments (50 mm) of long-term in vivo used silicone catheters were cleaned before testing (n = 33). Overall mechanical behavior was tested in a custom-made self-centering, torsion free carrier. Maximum force stress at failure, strain at failure and Young's modulus were determined and statistically analyzed. FINDINGS: Unused catheters showed no significant difference in testing. in vivo used catheters exhibited 20% lower maximal force than unused catheters (p < 0.001), strain at break (p ã€ˆ0,001), and 7% higher elastic modulus (p = 0.004; power: 0.845). Due to a constant cross section area, stress at failure was proportional to maximum force (p < 0.001). Relation between determined parameters and dwell times was non-significant. INTERPRETATION: In vivo long-term used silicone catheters showed significantly lower ultimate strength than unused ones. It is likely that in situ altering changes the mechanical properties of catheters and may potentially lead to failure.

Individualized arterial spin labeling background suppression by rapid T1 mapping during acquisition.

OBJECTIVE: Arterial spin labeling blood perfusion signal relies on the difference between a label and a control image. Background suppression pulses are commonly used to improve the contrast, yet these are based on estimates of tissue relaxation times. The aim of this study is to improve the perfusion contrast by individualizing the timing of these background suppression pulses by means of T1 mapping. METHODS: The optimized timing of the background suppression pulses is obtained by rapid T1 mapping employing the variable flip angle technique. Ten healthy volunteers were included in this study. To compare the results, visual grading and the Wilcoxon signed-rank test was used comparing three categories of image quality. RESULTS: The readers confirmed that the images of the proposed method generally show a higher signal-to-background ratio and cortical structures are better visible. Noise was mostly comparable to the standard method. Relative blood flow was statistically significant higher in the modified method. CONCLUSION: The individually optimized background suppression pulses improve the image appearance and allow for a better visualization of cortical structures. The proposed technique however prolongs scan time, which can be seen as negative result, yet needs to be further evaluated. KEY POINTS: • Background suppression timing in ASL can vary. • Both the label and control condition can be modified for T1 mapping. • Adapting the pulse timing improves the signal-to-background ratio.

Effects of pine processionary caterpillar Thaumetopoea pityocampa contact in dogs: 41 cases (2002-2006).

The pine processionary caterpillar, Thaumetopoea pityocampa, is considered an emerging pine pest in Mediterranean countries, with high medical relevance. In recent years, adverse reactions reports in humans following contact with T. pityocampa have been increasingly reported. Dogs living in pinewood areas are also frequently exposed to the caterpillar. This work consisted on a retrospective study of 41 cases of lepidopterism. All dogs presented drooling, dysphagia, submandibular lymphadenomegaly and clinical signs of pain. The animals were distributed in three groups, according to the time span from exposure to the caterpillar until presentation: up to 2 h (group 1), 2-5 h (group 2) and more than 5 h (group 3). All animals from groups 2 (n = 5) and 3 (n = 9), and eight dogs from group 1 (n = 27) developed lingual necrosis. Lepidopterism coursed through a predictable clinical pattern. The evolution was mainly dependent on the time span between exposure to the caterpillar and medical intervention, which should take place earlier than 2 h from exposure.

One year of Lamivudine therapy for portuguese patients with chronic hepatitis B.

OBJECTIVE: To assess the efficacy of lamivudine treatment on hepatitis B e antigen (HBeAg) and/or hepatitis B surface antigen (HBsAg) seroconversion, on other virological and serological markers of response including hepatitis B virus (HBV) DNA and serum aminotransferases, and the safety of lamivudine treatment in hepatitis B patients. PATIENTS: This phase III open-label study evaluated the virological and biochemical response to lamivudine in 70 Portuguese patients with HBeAg positive chronic hepatitis B. Patients were treated with lamivudine 100mg once daily for 12 months. METHODS: Antiviral activity was assessed by measuring alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels at all protocol visits, and hepatitis B serology and HBV DNA were performed at baseline and at month 12 visits. Evaluation of safety and tolerance was based on clinical adverse events and laboratory analyses. RESULTS: The primary endpoint was virological response at month 12, defined as loss of detectable HBeAg from serum with a reduction of HBV DNA to undetectable levels, and this was observed in 19/69 (27.5%) of patients. Almost half of the patients were HBV DNA negative by this time. Mean ALT values decreased steadily during treatment and by 12 months 61% of patients had values within the normal range. HBeAg seroconversion (HBeAg negative, HBeAb positive) was achieved in 27.9% of patients by 12 months, although all patients remained HBsAg positive. CONCLUSION: Lamivudine was well tolerated and the incidence of adverse events was similar to those reported in previous studies. Lamivudine treatment resulted in virological and biochemical improvements in HBeAg positive chronic hepatitis B patients, with HBeAg seroconversion in one-third of patients.

Evaluation of recombinant Leptospira antigen-based enzyme-linked immunosorbent assays for the serodiagnosis of leptospirosis.

There is an urgent need for development of new serodiagnostic strategies for leptospirosis, an emerging zoonosis with worldwide distribution. We have evaluated the diagnostic utility of five recombinant antigens in enzyme-linked immunosorbent assays (ELISAs) for serodiagnosis of leptospirosis. Sera from 50 healthy residents of a high-incidence region were used to determine cutoff values for 96% specificity. In paired sera from 50 cases of leptospirosis confirmed by the microscopic agglutination test, immunoglobulin G (IgG) but not IgM reacted with the recombinant leptospiral proteins. The recombinant LipL32 IgG ELISA had the highest sensitivities in the acute (56%) and convalescent (94%) phases of leptospirosis. ELISAs based on recombinant OmpL1, LipL41, and Hsp58 had sensitivities of 16, 24, and 18% during the acute phase and 72, 44, and 32% during convalescence, respectively. Compared to sera from healthy individuals, patient sera did not react significantly with recombinant LipL36 (P > 0.05). Recombinant LipL32 IgG ELISA demonstrated 95% specificity among 100 healthy individuals, and specificities ranging from 90 to 97% among 30 dengue patients, 30 hepatitis patients, and 16 patients with diseases initially thought to be leptospirosis. Among 39 Venereal Disease Research Laboratory test-positive individuals and 30 Lyme disease patients, 13 and 23% of sera, respectively, reacted positively with the rLipL32 antigen. These findings indicate that rLipL32 may be an useful antigen for the serodiagnosis of leptospirosis.

Leptospiral proteins recognized during the humoral immune response to leptospirosis in humans.

Leptospirosis is an emerging zoonosis caused by pathogenic spirochetes belonging to the genus Leptospira. An understanding of leptospiral protein expression regulation is needed to develop new immunoprotective and serodiagnostic strategies. We used the humoral immune response during human leptospirosis as a reporter of protein antigens expressed during infection. Qualitative and quantitative immunoblot analysis was performed using sera from 105 patients from Brazil and Barbados. Sera from patients with other diseases and healthy individuals were evaluated as controls. Seven proteins, p76, p62, p48, p45, p41, p37, and p32, were identified as targets of the humoral response during natural infection. In both acute and convalescent phases of illness, antibodies to lipopolysaccharide were predominantly immunoglobulin M (IgM) while antibodies to proteins were exclusively IgG. Anti-p32 reactivity had the greatest sensitivity and specificity: positive reactions were observed in 37 and 84% of acute- and convalescent-phase sera, respectively, while only 5% of community control individuals demonstrated positive reactions. Six immunodominant antigens were expressed by all pathogenic leptospiral strains tested; only p37 was inconsistently expressed. Two-dimensional immunoblots identified four of the seven infection-associated antigens as being previously characterized proteins: LipL32 (the major outer membrane lipoprotein), LipL41 (a surface-exposed outer membrane lipoprotein), and heat shock proteins GroEL and DnaK. Fractionation studies demonstrated LipL32 and LipL41 reactivity in the outer membrane fraction and GroEL and DnaK in the cytoplasmic fraction, while p37 appeared to be a soluble periplasmic protein. Most of the other immunodominant proteins, including p48 and p45, were localized to the inner membrane. These findings indicate that leptospiral proteins recognized during natural infection are potentially useful for serodiagnosis and may serve as targets for vaccine design.

Valor clínico y pronóstico del ecocardiograma en pacientes hemodializados crónicos / Clinical and prognostic value of echocardiogram in hemodialysis chronic patients

Con el fin de determinar la incidencia, gravedad y evolución de las alteraciones cardíacas en la insuficiencia renal terminal se realizaron ecocardiogramas modo M y 2-D previos a una hemodiálisis en 20 pacientes. En sólo 1 de ellos el estudio resultó normal. Se dividieron a los pacientes en 2 grupos según que cumplieran (grupo A, 9 pacientes) o no (grupo B, 11 pacientes) con 2 de los siguientes ítems: a) espesor septal en diástole > = 1,4cm; b) velocidad de acortamiento circunferencial < = 1,1, y c) masa ventricular > = 350g. El grupo A mostró mayor diámetro diastólico ventricular izquierdo, mayor espesor septal, menor velocidad de acortamiento circunferencial, mayor masa ventricular, mayor incidencia de edemas, de disnea y de insuficiencia cardíaca, y mayor edad. Se realizaron ecocardiogramas periódicos durante un promedio de 18 meses. Al finalizar el estudio 6 de los 9 pacientes del grupo A habían fallecido súbitamente o por edema agudo de pulmón. De los 11 pacientes del grupo B fallecieron 2 por causas extracardíacas. Estos resultados sugieren que mediante el ecocardiograma es posible separar 2 subgrupos de pacientes con diferencias significativas en cuanto a la gravedad de los trastornos cardíacos y a la sobrevida (AU)

Valor clínico y pronóstico del ecocardiograma en pacientes hemodializados crónicos / Clinical and prognostic value of echocardiogram in hemodialysis chronic patients

Con el fin de determinar la incidencia, gravedad y evolución de las alteraciones cardíacas en la insuficiencia renal terminal se realizaron ecocardiogramas modo M y 2-D previos a una hemodiálisis en 20 pacientes. En sólo 1 de ellos el estudio resultó normal. Se dividieron a los pacientes en 2 grupos según que cumplieran (grupo A, 9 pacientes) o no (grupo B, 11 pacientes) con 2 de los siguientes ítems: a) espesor septal en diástole > = 1,4cm; b) velocidad de acortamiento circunferencial < = 1,1, y c) masa ventricular > = 350g. El grupo A mostró mayor diámetro diastólico ventricular izquierdo, mayor espesor septal, menor velocidad de acortamiento circunferencial, mayor masa ventricular, mayor incidencia de edemas, de disnea y de insuficiencia cardíaca, y mayor edad. Se realizaron ecocardiogramas periódicos durante un promedio de 18 meses. Al finalizar el estudio 6 de los 9 pacientes del grupo A habían fallecido súbitamente o por edema agudo de pulmón. De los 11 pacientes del grupo B fallecieron 2 por causas extracardíacas. Estos resultados sugieren que mediante el ecocardiograma es posible separar 2 subgrupos de pacientes con diferencias significativas en cuanto a la gravedad de los trastornos cardíacos y a la sobrevida