Staphylococcal growth and enterotoxin production in the presence of meat cultures (non LAB)

The effect of meat cultures (non lactic acid bacteria) on the growth and production of enterotoxins and thermonuclease by Staphylococcus aureus was studied. Micrococcus varians did not affect growth nor the synthesis of metabolites. Levels of enterotoxins A, B and D produced by the respective S. aureus strains were reduced by S. xylosus, S. saprophyticus and S. carnosus. The two latter species prevented production of enterotoxin C(1) and S. xylosus markedly reduced the amount produced. The three coagulase-negative staphylococci showed little inhibitory effect on the growth of S. aureus. Penicillium nalgiovense did not show inhibitory activity against the four S. aureus strains. Debaryomyces hansenii slightly inhibited growth of the enterotoxin A-producing strain, but reduced enterotoxin synthesis at 30 °C. Thermonuclease was detected whenever enterotoxins were detected though the influence of the effector organism was dependent on the test strain.

90Y-DOTA-D-Phe1-Try3-octreotide in therapy of neuroendocrine malignancies

Somatostatin receptors type 2 (sst(2)) are expressed in high concentration on numerous neudoendocrine tumors. The successful use of radiolabeled somatostatin analogs in imaging promoted further studies in utilizing them in radiopeptide therapy. The somatostatin analog [(90)Y-DOTA-D-Phe(1)-Try3]octreotide (DOTATOC) (DOTA: 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) possesses favorable characteristic for its therapeutic use; shows high affinity for sst(2), moderately high affinity for sst(5), and intermediate affinity for sst(3); high hydrophilicity; stable and facile labeling with (111) In and (90) Y. In this article we report our experience with (90)Y-DOTATOC in neuroendocrine tumors. Eighty-seven patients with neuroendocrine tumors were treated with a cumulated activity ranging from 7.4 to 20.2 GBq. Most patients responded with stabilization of disease (48%); however, objective responses were observed in 28% of patients (5% complete response). No major acute reactions were observed up to the activity of 5.55 GBq per cycle. The dose limiting was bone marrow toxicity and the maximal tolerated dose was defined as 5.18 GBq.

Kikuchi's disease with multisystemic involvement and adverse reaction to drugs

Kikuchi's disease (KD), or histiocytic necrotizing lymphadenitis, was initially described in Japan in 1972. In the following years, several series of cases involving patients of different ages, races, and geographic origins were reported, but pediatric reports have been rare. The etiology of KD is unknown, although a viral or autoimmune hypothesis has been suggested. The most frequent clinical manifestation consists of local or generalized adenopathy, although in some cases, it is associated with more general symptoms, multiorganic involvement, and diverse analytic changes (leukopenia, elevated erythrocyte sedimentation rate, and C-reactive protein, as well as an increase of transaminases and serum lactic dehydrogenase). Diagnosis is based on characteristic pathologic findings that permit differentiation of this disease from lymphoma, systemic lupus erythematosus, and infectious lymphadenopathies. We present here the case of a 14-year-old boy who presented with severe systemic manifestations and transient fulminant hepatic failure in response to treatment with antituberculosis drugs. Kikuchi's disease, lymphadenitis, liver failure, antituberculosis drugs.

Study of the Effect of Solubilized Gases on the Properties of Microemulsion Droplets

The effect of dissolved gas (nitrogen, argon) on the properties of the droplets in water-in-oil and oil-in-water microemulsions (surfactant aggregation number, microviscosity, and micropolarity) has been investigated by means of time-resolved fluorescence quenching and spectrofluorometry. This study extends a similar one on aqueous micellar solutions (R. G. Alargova et al., Langmuir 14, 1575, 1998). The selected microemulsions were characterized by droplets of fairly large size and high volume fraction, in order to minimize the effect of the curvature of the surfactant layer and maximize the amount of gas that can be solubilized in the system. Within the experimental error, the investigated properties (surfactant aggregation number, intradroplet quenching rate constant which is related to the droplet microviscosity, and fluorescent probe lifetime and micropolarity) were found to be independent on whether the system was degassed, nitrogen-saturated, or argon-saturated, in the temperature range between 10 and 35 degrees C. The results confirm the conclusion reached in the above study; i.e., the effect of solubilized gases on the hydrophobic interaction which controls the formation of surfactant assemblies is extremely small and well below the sensitivity of the fluorescence probing techniques used in this investigation. Copyright 1999 Academic Press.

Microbial quality of lamb carcasses during processing and the acridine orange direct count technique (a modified DEFT) for rapid enumeration of total viable counts

This study was designed to set up a hazard analysis and critical control points (HACCP) system for sheep slaughtering operations at four different plants in Ireland and to determine the differences between plants in terms of microbial contamination. A single carcass area, the abdomen, was examined by swabbing and a microbiological profile was determined at different stages along the slaughter line. The level of contamination was assessed from the total bacteria counts, Enterobacteriaceae and Listeria spp. For the total counts, a modified direct epifluorescent filter technique (acridine orange direct count technique (AODC)) was developed and tested. No significant differences were found among plants in the levels of bacterial contamination. This was observed for all groups of organisms. The rapid direct technique (AODC) was found to be very successful. A correlation coefficient of 0.87 was obtained for this method and the standard plate count. Each test could be carried out in about 10-15 min and could be used to predict the standard plate count.

Two mutant alleles of the insulin receptor gene in a family with a genetic form of insulin resistance: a 10 base pair deletion in exon 1 and a mutation substituting serine for asparagine-462

Mutations in the insulin receptor gene cause several genetic syndromes associated with extreme insulin resistance. We have studied three insulin resistant siblings with acanthosis nigricans, dental abnormalities, and acral hypertrophy. The female patient also had primary amenorrhea due to hyperandrogenism. All three patients were compound heterozygotes with two mutant alleles of the insulin receptor gene. One allele had a 10-bp deletion in the region of exon 1 encoding the hydrophobic signal peptide; this leads to a frameshift and premature chain termination at codon 61. The deletion occurs at the site of a direct repeat of a hexanucleotide sequence interrupted by a tetranucleotide sequence; the deletion may have resulted from recombination between the upstream and downstream hexanucleotide repeats. In the other mutant allele, there is a missense mutation substituting serine for Asn462-a mutation identified previously in one allele of the insulin receptor gene in a patient with type-A insulin resistance. The Ser462 mutation impaired the ability of acidic pH to dissociate insulin from the receptor. Thus, Thus, like the previously described Glu460 mutation, the Ser462 mutation may retard dissociation of insulin from the receptor in the acidic compartment of the endosome and may, as a result, accelerate the rate of receptor degradation.

Staphylococcal growth and enterotoxins (A-D) and thermonuclease synthesis in the presence of dehydrated garlic

The inhibition of Staphylococcus aureus growth and enterotoxin and thermonuclease production by various concentrations of garlic (Allium sativum) was studied in BHI broth. The growth of Staph. aureus was inhibited by dehydrated garlic at levels of 1.5% (w/v) and over. Enterotoxins A, B and C1 were only detectable in broth containing < 1% of garlic while enterotoxin D was produced at a level of 2%. Garlic also inhibited thermonuclease (TNAse) production, complete inhibition being observed at levels > or = 1.5%. TNAse was not always detected when enterotoxin was present.

Isolation of two hemorrhagic toxins from Crotalus basiliscus basiliscus (Mexican west coast rattlesnake) venom and their effect on blood clotting and complement

1. Two hemorrhagic toxins of mol. wt 27,000 (B1) and 27,500 (B2) and pI 9.8 and 5.2 respectively were isolated from Crotalus basiliscus venom. 2. The two proteinases did not cross-react antigenically. 3. Both toxins caused hemorrhage in mice and each was capable of hydrolyzing hide power azure, casein, collagen and fibrin. 4. B1 hydrolyzed the A alpha, B beta and gamma chains of fibrinogen. B2 hydrolyzed the A alpha and B beta chains of fibrinogen, but not the gamma chain. 5. Both proteinases inactivated guinea pig complement.