946 resultados para Direct area of influence


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Bovine mastitis caused by Mycoplasma bovis is of great economic importance to the beef and dairy industry. Here we describe a new specific real-time PCR assay targeting the uvrC gene that was developed to directly detect M. bovis from milk and tissue samples without laborious DNA purification.

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To cite this article: Schroeder V, Kohler HP. New developments in the area of factor XIII. J Thromb Haemost 2013; 11: 234-44. Summary.  Coagulation factor (F)XIII is best known for its role in fibrin stabilization and cross-linking of antifibrinolytic proteins to the fibrin clot. From patients with congenital FXIII deficiency, it is known that FXIII also has important functions in wound healing and maintaining pregnancy. Over the last decade more and more research groups with different backgrounds have studied FXIII and have unveiled putative novel functions for FXIII. FXIII, with its unique role as a transglutaminase among the other serine protease coagulation factors, is now recognized as a multifunctional protein involved in regulatory mechanisms and construction and repair processes beyond hemostasis with possible implications in many areas of medicine. The aim of this review was to give an overview of exciting novel findings and to highlight the remarkable diversity of functions attributed to FXIII. Of course, more research into the underlying mechanisms and (patho-)physiological relevance of the many described functions of FXIII is needed. It will be exciting to observe future developments in this area and to see if and how these interesting findings may be translated into clinical practice in the future.

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Maternal effects are a mother¿s non-genetic contributions to development that alter phenotypic traits in offspring. Maternal effects can take the form of prenatal allocation of resources, such as the deposition of androgens into egg yolks. For example, elevated yolk testosterone increases male sexual behaviors such as copulation solicitation and courtship displays in some avian species, in addition to aggressive behaviors like pecks and intimidating postures towards same-sex competitors. However, the mechanism connecting in ovo testosterone exposure with changes in sexual and aggressive behaviors has yet to be elucidated. While testosterone released by the gonads is important in the activation of sexual behaviors, it must undergo conversion to estrogen by the enzyme aromatase in the pre-optic area (POA) of the avian brain for full expression of sexual activity. POA aromatase is also necessary for the activation of aggressive behaviors in male birds. This experiment tested the hypothesis that elevated yolk testosterone leads to changes in POA aromatase activity and levels of gonadal testosterone, as these two endocrine parameters may mediate the effect of yolk testosterone on the frequency of sexual and aggressive behaviors. The effect of elevated yolk testosterone on gonadal testosterone levels and aromatase activity in the POA of 3-day-old domestic chickens Gallus gallus domesticus was investigated. Unincubated eggs were injected with either 10 ng testosterone in 50 ¿L sesame oil (¿T chicks¿) or 50 ¿L sesame oil (¿C chicks¿). At 3 days post-hatch, gonadal testosterone content was measured after steroid extraction using an EIA, and aromatase activity in the POA was quantified by measuring the production of tritiated water from [1ß-3H]-androstenedione. I predicted that gonadal testosterone levels and brain aromatase activity would be higher in T chicks, however found no difference between treatments. Though juvenile T production peaks at 3 days post-hatch, it is possible that the reproductive systems, including the testes and POA, are not fully developed at this time.

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BACKGROUND: Tuberculin skin testing (TST) and preventive treatment of tuberculosis (TB) are recommended for all persons with human immunodeficiency virus (HIV) infection. We aimed to assess the effect of TST and preventive treatment of TB on the incidence of TB in the era of combination antiretroviral therapy in an area with low rates of TB transmission. METHODS: We calculated the incidence of TB among participants who entered the Swiss HIV Cohort Study after 1995, and we studied the associations of TST results, epidemiological and laboratory markers, preventive TB treatment, and combination antiretroviral therapy with TB incidence. RESULTS: Of 6160 participants, 142 (2.3%) had a history of TB at study entry, and 56 (0.91%) developed TB during a total follow-up period of 25,462 person-years, corresponding to an incidence of 0.22 cases per 100 person-years. TST was performed for 69% of patients; 9.4% of patients tested had positive results (induration > or = 5 mm in diameter). Among patients with positive TST results, TB incidence was 1.6 cases per 100 person-years if preventive treatment was withheld, but none of the 193 patients who received preventive treatment developed TB. Positive TST results (adjusted hazard ratio [HR], 25; 95% confidence interval [CI], 11-57), missing TST results (HR, 12; 95% CI, 4.8-20), origin from sub-Saharan Africa (HR, 5.8; 95% CI, 2.7-12.5), low CD4+ cell counts, and high plasma HIV RNA levels were associated with an increased risk of TB, whereas the risk was reduced among persons receiving combination antiretroviral therapy (HR, 0.44; 95% CI, 0.2-0.8). CONCLUSION: Screening for latent TB using TST and administering preventive treatment for patients with positive TST results is an efficacious strategy to reduce TB incidence in areas with low rates of TB transmission. Combination antiretroviral therapy reduces the incidence of TB.

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PURPOSE: To test the hypothesis that the extension of areas with increased fundus autofluorescence (FAF) outside atrophic patches correlates with the rate of spread of geographic atrophy (GA) over time in eyes with age-related macular degeneration (AMD). METHODS: The database of the multicenter longitudinal natural history Fundus Autofluorescence in AMD (FAM) Study was reviewed for patients with GA recruited through the end of August 2003, with follow-up examinations within at least 1 year. Only eyes with sufficient image quality and with diffuse patterns of increased FAF surrounding atrophy were chosen. In standardized digital FAF images (excitation, 488 nm; emission, >500 nm), total size and spread of GA was measured. The convex hull (CH) of increased FAF as the minimum polygon encompassing the entire area of increased FAF surrounding the central atrophic patches was quantified at baseline. Statistical analysis was performed with the Spearman's rank correlation coefficient (rho). RESULTS: Thirty-nine eyes of 32 patients were included (median age, 75.0 years; interquartile range [IQR], 67.8-78.9); median follow-up, 1.87 years; IQR, 1.43-3.37). At baseline, the median total size of atrophy was 7.04 mm2 (IQR, 4.20-9.88). The median size of the CH was 21.47 mm2 (IQR, 15.19-28.26). The median rate of GA progression was 1.72 mm2 per year (IQR, 1.10-2.83). The area of increased FAF around the atrophy (difference between the CH and the total GA size at baseline) showed a positive correlation with GA enlargement over time (rho=0.60; P=0.0002). CONCLUSIONS: FAF characteristics that are not identified by fundus photography or fluorescein angiography may serve as a prognostic determinant in advanced atrophic AMD. As the FAF signal originates from lipofuscin (LF) in postmitotic RPE cells and since increased FAF indicates excessive LF accumulation, these findings would underscore the pathophysiological role of RPE-LF in AMD pathogenesis.

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We showed that when CA3 pyramidal neurons in the caudal 80% of the dorsal hippocampus had almost disappeared completely, the efferent pathway of CA3 was rarely detectable. We used the mouse pilocarpine model of temporal lobe epilepsy (TLE), and injected iontophoretically the anterograde tracer phaseolus vulgaris leucoagglutinin (PHA-L) into gliotic CA3, medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei, or the retrograde tracer cholera toxin B subunit (CTB) into gliotic CA3 area of hippocampus. In the afferent pathway, the number of neurons projecting to CA3 from medial septum and the nucleus of diagonal band of Broca, median raphe, and lateral supramammillary nuclei increased significantly. In the hippocampus, where CA3 pyramidal neurons were partially lost, calbindin, calretinin, parvalbumin immunopositive back-projection neurons from CA1-CA3 area were observed. Sprouting of Schaffer collaterals with increased number of large boutons in both sides of CA1 area, particularly in the stratum pyramidale, was found. When CA3 pyramidal neurons in caudal 80% of the dorsal hippocampus have almost disappeared completely, surviving CA3 neurons in the rostral 20% of the dorsal hippocampus may play an important role in transmitting hyperactivity of granule cells to surviving CA1 neurons or to dorsal part of the lateral septum. We concluded that reorganization of CA3 area with its downstream or upstream nuclei may be involved in the occurrence of epilepsy.

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Resistance of trypanosomes to melarsoprol is ascribed to reduced uptake of the drug via the P2 nucleoside transporter. The aim of this study was to look for evidence of drug resistance in Trypanosoma brucei gambiense isolates from sleeping sickness patients in Ibba, South Sudan, an area of high melarsoprol failure rate. Eighteen T. b. gambiense stocks were phenotypically and only 10 strains genotypically characterized. In vitro, all isolates were sensitive to melarsoprol, melarsen oxide, and diminazene. Infected mice were cured with a 4 day treatment of 2.5mg/kg bwt melarsoprol, confirming that the isolates were sensitive. The gene that codes for the P2 transporter, TbATI, was amplified by PCR and sequenced. The sequences were almost identical to the TbAT1(sensitive) reference, except for one point mutation, C1384T resulting in the amino acid change proline-462 to serine. None of the described TbAT1(resistant)-type mutations were detected. In a T. b. gambiense sleeping sickness focus where melarsoprol had to be abandoned due to the high incidence of treatment failures, no evidence for drug resistant trypanosomes or for TbAT1(resistant)-type alleles of the P2 transporter could be found. These findings indicate that factors other than drug resistance contribute to melarsoprol treatment failures.

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We prospectively investigated urinary iodine concentration (UIC) in pregnant women and in female, non-pregnant controls in the canton of Berne, Switzerland, in 1992. Mean UIC of pregnant women [205 +/- 151 microg iodine/g creatinine (microg l/g Cr); no. = 153] steadily decreased from the first (236 +/- 180 microg l/g Cr; no. = 31) to the third trimester (183 +/- 111 microg l/g Cr, p < 0.0001; no. = 66) and differed significantly from that of the control group (91 +/- 37 microg l/g Cr, p < 0.0001; no. = 119). UIC increased 2.6-fold from levels indicating mild iodine deficiency in controls to the first trimester, demonstrating that high UIC during early gestation does not necessarily reflect a sufficient iodine supply to the overall population. Pregnancy is accompanied by important alterations in the regulation of thyroid function and iodine metabolism. Increased renal iodine clearance during pregnancy may explain increased UIC during early gestation, whereas increased thyroidal iodine clearance as well as the iodine shift from the maternal circulation to the growing fetal-placental unit, which both tend to lower the circulating serum levels of inorganic iodide, probably are the causes of the continuous decrease of UIC over the course of pregnancy. Mean UIC in our control group, as well as in one parallel and several consecutive investigations in the same region in the 1990s, was found to be below the actually recommended threshold, indicating a new tendency towards mild to moderate iodine deficiency. As salt is the main source of dietary iodine in Switzerland, its iodine concentration was therefore increased nationwide in 1998 for the fourth time, following increases in 1922, 1965 and 1980.