Primary leiomyosarcoma of the greater omentum: case report and review of the literature

Omental leiomyosarcomas are rare intra-abdominal tumors. This report describes a case of primary leiomyosarcoma of the greater omentum discovered on abdominal CT scan. The mass was removed via laparotomy and an omentectomy performed. At 2 years postoperatively there is no sign of tumor recurrence or metastasis.     

Taxol plus recombinant human granulocyte-colony stimulating factor as initial and as salvage chemotherapy for metastatic breast cancer: a preliminary report

Twenty-eight patients received Taxol as their first chemotherapy for stage IV breast cancer. An additional 51 patients with extensive prior exposure to other chemotherapeutic agents received Taxol as salvage therapy. We found significant activity for the drug in both situations, as well as a strong clinical suggestion of non-cross-resistance with doxorubicin. An excellent response in previously irradiated skin was noted in one case. The routine use of recombinant human granulocyte-colony stimulating factor seemed to ameliorate some of the dose-limiting toxicity of neutropenia. Other toxicity was mild to moderate in most cases. With further development, Taxol should play a significant role in the systemic management of breast cancer.     

D-Amino Acids in Milk as Related to Heat Treatments and Bacterial Activity

The occurrence in milk of free and bound D-amino acids was investigated by chiral phase GC and related to heat treatments and bacterial activity. Significant amounts of free D-alanine (D-Ala), D-aspartic acid (D-Asp), and D-glutamic acid (D-Glu) have been found in raw cow milk but not in human milk. The amount did not increase by pasteurization, UHT treatment, and sterilization. In contrast, the content of D-Ala in raw milk samples increased during cold storage at 4°C, and it was suggested that D-Ala may be considered as an indicator of bacterial milk contamination. The presence of D-Ala, D-Asp and D-Glu detected in milk protein hydrolysates was due to hydrolysis conditions.     

Phosphorylation-independent activity of the response regulators AlgB and AlgR in promoting alginate biosynthesis in mucoid Pseudomonas aeruginosa

Overproduction of the capsular polysaccharide alginate appears to confer a selective advantage for Pseudomonas aeruginosa in the lungs of cystic fibrosis patients. The regulators AlgB and AlgR, which are both required as positive activators in alginate overproduction, have homology with the regulator class of two-component environmental responsive proteins which coordinate gene expression through signal transduction mechanisms. Signal transduction in this class of proteins generally occurs via autophosphorylation of the sensor kinase protein and phosphotransfer from the sensor to a conserved aspartate residue, which is present in the amino terminus of the response regulator. Recently, kinB was identified downstream of algB and was shown to encode the cognate histidine protein kinase that efficiently phosphorylates AlgB. However, we show here that a null mutation in kinB in a mucoid cystic fibrosis isolate, P. aeruginosa FRD1, did not block alginate production. The role of the conserved aspartate residue in the phosphorylation of AlgB was examined. The predicted phosphorylation site of AlgB (D59) was mutated to asparagine (N), and a derivative of an AlgB lacking the entire amino-terminal phosphorylation domain (AlgB delta1-145) was constructed. A hexahistidine tag was included at the amino terminus of the wild-type (H-AlgB), H-AlgB delta1-145, and mutant (H-AlgB.59N) AlgB proteins. These derivatives were purified by Ni2+ affinity chromatography and examined for in vitro phosphorylation by the purified sensor kinase protein, KinB. The results indicated that while KinB efficiently phosphorylated H-AlgB, no phosphorylation of H-AlgB delta1-145 or H-AlgB.D59N was apparent. An allelic exchange system was developed to transfer mutant algB alleles onto the chromosome of a P. aeruginosa algB mutant to examine the effect on alginate production. Despite the defect in AlgB phosphorylation, P. aeruginosa strains expressing AlgB.D59N or H-AlgB delta1-145 remained mucoid. The roles of the conserved aspartate residues in the phosphorylation of AlgR were also examined. As seen with AlgB, mutations in the predicted phosphorylation site of AlgR (AlgR.D54N and AlgR.D85N) did not affect alginate production. These results indicate that in vivo phosphorylation of AlgB and AlgR are not required for their roles in alginate production. Thus, the mechanism by which these response regulators activate alginate genes in mucoid P. aeruginosa appears not to be mediated by conventional phosphorylation-dependent signal transduction.     

Rapid p-Nitroaniline Test for Assessing Microbial Quality of Refrigerated Meat

The p-nitroaniline test, a rapid method to estimate microbial quality of refrigerated meat, was applied to many retail meat samples from several animal species to confirm its applicability. This method allows determination of psychotroph levels between 10⁴ and 10⁸ CFU/cm² in about 2.5 hr. A good correlation was found (r = 0.88, p < 0.001) between this method and the standard plate count technique. Because of the yellow color of the p-nitroaniline released during reaction, bacterial loads higher than 10^s CFU/cm² develop a color intense enough to be detected visually.