Successions of rare and abundant microbial subcommunities during fish carcass decomposition in a microcosm under the influence of variable factors.

Animal carcasses are hotspots of ecological activity. The study of the role of microbes in carcass decomposition has been exclusively focused on microbes with higher abundance. The comparative study of abundant and rare subcommunities associated with decomposition needs in-depth exploration. The current experiment has been conducted on the decomposition of a fish carcass in a microcosm. We conducted 16S rRNA gene sequencing of the microbial communities. The correlation of the physicochemical properties of tap and Yellow river water with the microbial communities was evaluated. Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria were found to be the dominant phyla in both abundant and rare subcommunities. Among bacteria, the Acidobacteria, Planctomycetes, and Cyanobacteria were found only in the rare subcommunity. In both subcommunities, the abundance of Proteobacteria was found to increase over time, and that of Firmicutes to decrease. The rare subcommunity shows higher alpha diversity than the abundant one. The variation in the abundant subcommunity was influenced by time and water type, and that in the rare subcommunity was influenced by pH and water type. These results have implications for future research on the ecological role of rare and abundant subcommunities in the decomposition of carcasses in the aquatic ecosystem.

Genotyping of Streptococcus agalactiae strains isolated from fish, human and cattle and their virulence potential in Nile tilapia.

Streptococcus agalactiae (Lancefield group B; GBS) is a pathogen that causes meningoencephalitis in fish, mastitis in cows, and neonatal sepsis in humans. The objective of this study was to characterize S. agalactiae isolated from fish (n=27), cows (n=9), and humans (n=10) using pulsed-field gel electrophoresis (PFGE) and to investigate the virulence of the identified strains in Nile tilapia (Oreochromis niloticus). The PFGE types were determined by dendogram analyses and the in vivo virulence was evaluated by experimental infection (using i.p. and immersion routes) of Nile tilapia. Among the fish strains, 5 different PFGE patterns were observed and 21 strains showed the same genetic pattern. In some farms two or three profiles occurred simultaneously. The bovine and human strains exhibited high genetic diversity and few relationships were established among S. agalactiae strains from the three host origins analyzed. Eight S. agalactiae strains from fish caused high mortality of Nile tilapia. Three bovine strains infected Nile tilapia (by i.p. route) and two of those strains caused clinical signs of meningoencephalitis. All human strains (n=5) infected Nile tilapia (by i.p. route) and meningoencephalitis was induced by one strain (by both i.p. and immersion routes). In conclusion, the analyzed strains from the three natural hosts did not show genetic relatedness, yet some of the bovine and human strains were able to infect fish and cause meningoencephalitis. We suggest that genetic linkage is not a prerequisite for S. agalactiae to cross the host-specific barrier.

Aspects of the natural history and virulence of S. agalactiae infection in Nile tilapia.

Streptococcus agalactiae is an emerging pathogen in Nile tilapia (Oreochromis niloticus) worldwide. To investigate aspects of the epidemiology, transmission and virulence of S. agalactiae infections, nine outbreaks of meningoencephalitis and septicemia in Nile tilapia farms in Brazil were analyzed. Records from the outbreaks revealed large variation in the weight of fish affected, high mortality, and disease occurrence at water temperatures above 26 degrees C. S. agalactiae was isolated from diseased fish from all farms, and 29 strains were identified by phenotypic tests and 16S rRNA gene sequencing. Five strains from different geographic origins were selected to determine the 50% lethal dose (LD(50)). All strains were highly virulent; for example, strain SA 20-06 had an LD(50) of 90 bacteria. To investigate S. agalactiae transmission, we conducted cohabitation assays with diseased and healthy fish and fish challenges using an immersion bath or gill inoculation. Strain SA 20-06 was used in all assays. The disease was reproduced with characteristic clinical signs and S. agalactiae was reisolated in all trials. The infection route studies were identified as by direct contact or through the water. In conclusion, S. agalactiae, a major pathogen of Nile tilapia in Brazil, exhibited high virulence, regardless of the geographic origin of the isolated strains.

Uso da citologia aspirativa do parênquima testicular no diagnóstico de Azoospermia em um cão da raça pastor alemão

O artigo não apresenta resumo.

Synthesis filter bank optimization in two-dimensional separable subband coding systems.

Subband coding is a popular and well established technique used in visual communications, such as image and video transmission. In the absence of quantization and transmission errors, the analysis and synthesis filters in a subband coding scheme can be designed to obtain perfect reconstruction of the input signal, but this is no longer the optimal solution in the presence of quantization of the subband coefficients. We presuppose the use of a two-dimensional (2-D) separable subband scheme and we address the problem of designing, for a given analysis filter bank and assuming uniform quantization of the subband coefficients, the set of row and column synthesis filters that minimize the mean squared reconstruction error at the output of the subband system. Since the corresponding optimization problem is inherently nonlinear, we propose a suboptimal solution that extends a one-dimensional (l-D) optimal filter design procedure, already presented in the literature, to a 2-D separable synthesis filter bank. The separable 2-D extension is not trivial, since the processing in one direction, e.g., the rows, alters the statistics of the signals for the design of the filters in the other direction, e.g., the columns. To further simplify the filter design, we propose to model the input image as a 2-D separable Markov process plus an additive white component. Several design examples using both synthetic signals and real world images are presented, showing that the filters designed using the proposed technique can give a significant gain with respect to the perfect reconstruction solution, especially when the dither technique is used for quantization. The simulation results also show that the proposed image model can be conveniently used in the synthesis filter design procedure.

Response of the canine bladder base during reflex micturition.

The response of the bladder base to filling and voiding was studied in a surgical dog model in which the bladder base was separated from the main body and closed to form a chamber. In the bladder distension phase there was a reduction in pressure in the bladder base chamber, which implies relaxation of the bladder base. In the expulsion phase the reflex bladder body activity took place with an increase in bladder base pressure, indicating contraction. Relaxation and contraction were blocked by propranolol and phentolamine respectively and both responses were abolished by trimetaphan. It was concluded that the bladder base activity in the micturition cycle is a reflex action mediated via the sympathetic nervous system.

[Behavior of some acute phase reactant proteins during phlogosis and neoplasms and their correlation with erythrocyte sedimentation rate]. / Comportamento di alcune proteine della fase acuta in corso di flogosi e di neoplasie, e loro correlazione con la V.E.S.

Alpha 2 macroglobulin, haptoglobin and fibrinogen plasma levels were simultaneously determined, as well as E.S.R., to test if a significant difference could be found among cancer, inflammatory diseases and control subjects. Haptoglobin was higher in the cancer group and fibrinogen in inflammatory diseases, but these selective increases are not believed to be enough to suggest the widespread determinations of these proteins. A significant correlation was found between alpha 2 macroglobulin and E.S.R., as well as between fibrinogen and E.S.R.

[Concentration and reinfusion of ascitic fluid in liver cirrhosis]. / La concentrazione e reinfusione dell'ascite nella cirrosi epatica.

46 concentration-reinfusion treatments were performed on 36 patients, suffering from refractory ascites for liver cirrhosis. The procedure was well tolerated, improved the status of the patients and enabled diuretic to be effective again, in some cases for as long as two years. The usefulness of infusing autologous, non-denatured proteins in high dosage is stressed. The Authors belive that hepatorenal syndrome, severe hypokaliemia or hyposodemia and encephalopathy are the elective indications for the treatment.

[Role of alpha 1-antitrypsin and alpha-2 macroglobulin in hepatopathies]. / Ruolo dell'alpa 1-antitripsina e dell'alfa 2-macroglobulina nelle epatopatie.

Two pictures of alpha 1-antitrypsin deficiency, one associated with alpha 2-macroglobulin deficiency and one isolated case of the latter deficiency have been observed in three patients suffering from cirrhosis of the liver and/or hepatoma. On the basis of these cases, the literature on the subject is reviewed. The unusually high incidence of such anti-enzymatic deficiencies (three cases in the first eleven patients studied) in severe liver pathology, calls for a reassessment of such research and suggests that these tests should be carried out on a routine basis in cases of cryptogenetic cirrhosis and probably for long-term prognosis in cases of viral hepatitis.

[Erythrocyte changes during alcoholism and chronic liver diseases]. / Alterazioni eritrocitarie in corso di etilismo e di epatopatie croniche.

50 patients with chronic liver disease and/or alcoholism were studied. 28 cases of anemia were found and macrocytes (and target m.), spurr-cells, spherocytes and stomatocytes observed. For each of these abnormalities the authors report the observed incidence and discuss the literature's data about the pathogenesis. A personal research on the influence of the liver's impaired capability of protein synthesis was also carried out. The usefulness of a careful examination of the blood film is finally stressed, in patients with liver disease and to discover alcoholic subjects still "healthy".

[Gamma glutamly transpeptidase in chronic anicteric hepatopathies]. / La gamma-glutamil-transpeptidasi nelle epatopatie cronich anitteriche

Serum levels of gammaGT were determined in 51 patients suffering from bioptically verified chronic anictereric liber disease. GammaGT proved to be much more sensitive than the other enzymes studied and presented a significant increase particularly in cases of steatosis and chronic "alcoholic" liver disease with a markedly steatosic character.