Isolation and evaluation of autochthonous Bacillus subtilis strains as probiotics for fat snook (Centropomus parallelus Poey, 1860)

The objective of this study was to isolate and select autochthonous strains of Bacillus subtilis from the fat snook, Centropomus parallelus, and examine the viability of the Bacillus bacteria to determine their beneficial effect on gut colonization in reared fish. Twenty strains of Bacillus were isolated and further confirmed as B. subtilis using PCR. Among the 20 strains, two strains (B02 and B03) exhibited an inhibitory performance against five tested pathogens. The Bacillus strains B02 and B03 were added to the fish ration, and after 30 days the number of viable colonies were maintained or increased under the conditions of refrigeration (5°C), freezing (?18°C), or room temperature (30°C). These strains showed a growth rate of 0.18–0.21 h and a doubling time of 3.34–3.9 h. Both strains were tolerant to variations in NaCl, and B03 was also tolerant to bile exposure. The ability to colonize the gastrointestinal tract was also examined in healthy fat snook juveniles fed diets enriched for 30 days with strains B02 and B03. The amount of B. subtilis in the gastrointestinal juvenile tract was significantly higher in fish fed the enriched ration compared to controls. Based on these results, strains B02 and B03 were considered as candidate probiotics for fat snook.     

Development of a semidefined growth medium for Pedobacter cryoconitis BG5 using statistical experimental design

Pedobacter cryoconitis BG5 are psychrophiles isolated from the cold environment and capable of proliferating and growing well at low temperature regime. Their cellular products have found a broad spectrum of applications, including in food, medicine, and bioremediation. Therefore, it is imperative to develop a high-cell density cultivation strategy coupled with optimized growth medium for P. cryoconitis BG5. To date, there has been no published report on the design and optimization of growth medium for P. cryoconitis, hence the objective of this research project. A preliminary screening of four commercially available media, namely tryptic soy broth, R2A, Luria Bertani broth, and nutrient broth, was conducted to formulate the basal medium. Based on the preliminary screening, tryptone, glucose, NaCl, and K₂HPO₄ along with three additional nutrients (yeast extract, MgSO₄, and NH₄Cl) were identified to form the basal medium which was further analyzed by Plackett–Burman experimental design. Central composite experimental design using response surface methodology was adopted to optimize tryptone, yeast extract, and NH₄Cl concentrations in the formulated growth medium. Statistical data analysis showed a high regression factor of 0.84 with a predicted optimum optical (600?nm) cell density of 7.5 using 23.7?g/L of tryptone, 8.8?g/L of yeast extract, and 0.7?g/L of NH₄Cl. The optimized medium for P. cryoconitis BG5 was tested, and the observed optical density was 7.8. The cost-effectiveness of the optimized medium was determined as 6.25 unit prices per gram of cell produced in a 250-ml Erlenmeyer flask.     

An Outbreak of Bartonella bacilliformis in an Endemic Andean Community

Background

Bartonellosis affects small Andean communities in Peru, Colombia and Ecuador. Research in this area has been limited.

Methods

Retrospective review of 191 cases of bartonellosis managed in Caraz District Hospital, Peru, during the last outbreak (2003).

Results

The majority of cases (65%) were 14 years old and younger. There was a peak in acute cases after the rainy season; chronic cases presented more constantly throughout the year. The sensitivity of blood smear against blood culture in acute disease was 25%. The most commonly used treatment for chronic disease was rifampicin; chloramphenicol was used to treat most acute cases. Complications arose in 6.8% and there were no deaths.

Conclusions

Diagnostic and treatment algorithms for acute and chronic bartonellosis have been developed without a strong evidence base. Preparation of ready-to-go operational research protocols for future outbreaks would strengthen the evidence base for diagnostic and treatment strategies and enhance opportunities for control.     

Surface Molecules Released by Trypanosoma cruzi Metacyclic Forms Downregulate Host Cell Invasion

BackgroundThe question whether metacylic trypomastigote (MT) forms of different T. cruzi strains differentially release surface molecules, and how they affect host cell invasion, remains to be fully clarified. We addressed that question using T. cruzi strains that differ widely in the ability to invade cells.Conclusion/SignificanceOur data suggest that the surface molecules spontaneously released by MT impair parasite-host cell interaction, gp82 presumably competing with the molecule expressed on MT surface for the host cell receptor, and gp90 further contributing to down modulate invasion.     

Evolution of the Simiiformes and the phylogeny of human chromosomes

Summary This paper is based on the results of Primate chromosome studies obtained using high resolution techniques in our and other laboratories. We discuss the origin and the evolution of the chromosomes in the human karyotype and the time in evolution of the Simiiformes when they acquired their present morphology. Our results indicate that the chromosomes that underwent a higher number of reorganizations during the evolution of the Simiiformes coincide with the chromosomes most often implicated in human chromosome pathology. We describe the main reorganizations that took place during Primate evolution. Centromere activation and inactivation and heterochromatin changes are discussed as mechanisms of chromosome evolution.     

Sparse distribution of γ/δ T lymphocytes around human epithelial tumors predominantly infiltrated by primed/memory T cells

Summary Evidence from the mouse system has suggested that T lymphocytes accumulating in non-lymphoid tissue, in particular epithelia, may preferentially express the T cell receptor (TCR) . In this study, we characterize the T cell receptor or phenotype of lymphocytes infiltrating human tumors of epithelial origin using monoclonal antibodies (mAb) for immunohistology and flow cytometry on cells extracted by enzyme digestion. This report shows that the majority of CD3⁺ tumor-infiltrating lymphocytes are TCR ⁺ but a small percentage of TCR can be clearly defined scattered throughout the tumor tissue with apparently no microanatomical selection. So far there has been little evidence for an accumulation of activated T cells in human tumor tissues as defined by mAb against molecules appearing transiently during the acute phase of activation. Now mAb are available that can identify primed or memory T cells such as mAb UCHL-1 recognizing the CD45RO antigen. Here we show that CD3⁺ tumor-infiltrating lymphocytes have a statistically significant accumulation of primed T cells, as compared to the autologous peripheral blood lymphocytes, suggesting their immune stimulation by tumor cells.     

Comparison of the proteins in pancreatic juice in normal and diseased humans. Determination of serum proteins and demonstration of a particular protein in chronic calcifying pancreatitis

For a better understanding of the molecular mechanism leading to intraductal precipitation of proteins in primary chronic calcifying pancreatitis in man, we studied the composition of normal and pathological human pancreatic juice by immunotechniques. We found an increased level of serum proteins in pathological juices: 12.47% of total proteins compared to 1.8% in normal ones; albumin is 8.16% of the total proteins, IgG 2.84%, IgA 0.83% and IgM 0.91%. Transferrin and alpha 2-macroglobulin are present, but were not estimated. The albumin/IgA and albumin/IgG ratios favour the hypothesis of a local synthesis of these immunoglobulins as was shown in normal juice. The cross adsorption of antisera against pancreatic juice showed the presence in the pathological juice of a normal molecule in much higher concentration. The role of these proteins in precipitation is discussed.     

No Orcadian Rhythms of Serotoninergic, Alpha-, Beta-Adrenergic and Imipramine Binding Sites in Rat Brain Regions

B_max values of the specific binding of [³H]-WB 4101, [³H]-dihydroalprenolol, [³H]-spiperone and [³H]-imipramine to various rat brain regions were determined at 4 hr intervals over 24 hr under circadian conditions. No significant circadian rhythm of binding sites number was found for any receptor investigated in cerebral cortex, hypothalamus or brain stem. Some methodological issues are discussed.     

Fatty acid synthesis in vivo. Transfer of lipids from microsomes to other subcellular fractions of rat liver

At various times after the intraperitoneal injection of Na acetate-1-C¹⁴ to male Wistar rats, the labelled fatty acids are nonuniformely distributed among the lipids of liver microsomes, mitochondria and cell sap. The changes observed in the specific radioactivity of the neutral and phospholipids support the hypothesis that a transfer of these lipids takes place from the site of synthesis (endoplasmic reticulum) to mitochondria and cell sap. This phenomenon is probably responsible for the decline of microsomal fatty acids in favour of the mitochondrial and soluble fractions. In this connection, the deacylation-reacylation process does not seem to be involved.