Improved microbiological procedure for determining bacitracin in premixes and mixed feeds

An improved microbiological procedure is presented for determining bacitracin in premixes and mixed feeds. Premixes are extracted with acidic 50% aqueous methanol, and mixed feeds are extracted with 50% dimethylformamide after washing with acetone to remove fats and pigments. Extracts are diluted with pH 6.0 phosphate buffer and assayed by using a 2-point assay system with Micrococcus flavus as the test organism. The simpler extraction coupled with the 2-point assay system measured bacitracin levels as low as 10 g/ton. Accuracy and repeatability of the 2-point system were at least equivalent to those for official AOAC methods.     

The problem mastoid cavity: medical and surgical management

The patient with persistent foul drainage from a previously operated-on mastoid cavity has a serious problem that requires aggressive attention from the otologic surgeon. The ear must be carefully evaluated in the office. Careful cleaning of the cavity and effective application of medication will dry up many of these cavities. Revision surgery of the ear requires a systematic approach using all the techniques of modern otologic surgery. This means the use of a post-auricular incision and wide bone removal combined with bone removal combined with obliteration techniques and grafting of the middle ear. This approach was used in 29 ears in 27 patients. Rapid healing and a trouble-free, dry ear was obtained in 26 patients or 90% of the operated-on cases.     

Are central cholinergic paths involved in habituation of exploration and distraction?

Experiment 1 tested the generality of Carlton's hypothesis that central muscarinic cholinergic pathways are involved in habituation of exploration. The effects of 3 muscarinic antagonists were tested in a holeboard, under 2 test conditions, i.e. with objects absent or present. Both the frequency and the duration of head-dipping were used as measures of exploration. Scopolamine prevented habituation only of the frequency of head-dipping, and only when objects were present. Atropine and benzhexol did not impair the habituation of either frequency of duration of head-dipping in either test condition. The impairment of habituation seemed therefore to be specific to scopolamine, and to the more complex test condition, and thus there was little to justify the suggestion that central cholinergic paths were generally involved. Experiment 2 investigated the effects of muscarinic antagonists on habituation of distraction. None of the drugs affected the distraction to tones, nor the subsequent habituation to these stimuli. Central cholinergic paths do not therefore seem to be involved in habituation of this behavioral response.     

Regional distribution of substance P in the brain of the rat

Using a sensitive radioimmunoassay we have studied the regional distribution of substance P. The level of substance P is higher in the mesencephalon, hypothalamus and preoptic area than in other regions of the brain. Substance P is found in especially high concentrations in the reticular part of the substantia nigra and the interpeduncular nucleus. It is present in large amounts in several septal, preoptic and hypothalamic nuclei as well.     

Somatic cell cloned transgenic bovine neurons for transplantation in parkinsonian rats

OBJECTIVE: To identify consistent relevant mechanisms of small intestinal dysfunction in cats with experimentally induced feline immunodeficiency virus infection (FIV) that developed chronic diarrhea during the time they were being used in studies of pathogenicity and transmission of FIV. ANIMALS: 10 cats. PROCEDURE: The following investigative tests and techniques were performed on each of the cats: routine hematologic and serum biochemical analyses; urinalysis; fecal parasitologic and microbiologic examinations; breath hydrogen lactulose (BH2LT) and xylose (BH2XT) tests; intestinal permeability test; endoscopic examination of the intestinal mucosa; bacteriologic culture of endoscopically collected small intestinal juice; and histologic examination of endoscopically obtained intestinal biopsy specimens. RESULTS: Neutrophilia was evident in 3 cats, and lymphopenia was detected in 2 cats. Serum biochemical abnormalities were not observed. Urinalysis results were unremarkable. Fecal bacteriologic and parasitologic results were normal, except for isolation of Campylobacter sp from 1 cat. Abnormal BH2XT values suggestive of D-xylose malabsorption were identified in 2 cats, and BH2LT values indicated evidence of small intestinal bacterial overgrowth in 1 cat. Finally, permeability test results, quantitation of bacterial flora from the proximal part of the small intestine and histologic examination of biopsy specimens did not reveal any abnormalities. CONCLUSIONS: Enteric pathogens did not account for the development of diarrhea in cats with experimentally induced FIV infection, and consistent relevant mechanisms of small intestinal dysfunction were not identified.     

Isolation and identification of a cardioactive peptide from Tenebrio molitor and Spodoptera eridania

We isolated several cardioactive peptides from extracts of whole heads of the mealworm, Tenebrio molitor, and the southern armyworm, Spodoptera eridania, using a semi-isolated heart of Manduca sexta for bioassay. We have now isolated from each species the peptide with the strongest effect on rate of contraction of the heart. The peptides were identified using micro Edman sequencing and mass spectrometric methods. This cardioactive peptide has the same primary structure from both species: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, a cyclic nonapeptide which is identical to crustacean cardioactive peptide (CCAP) originally isolated from the shore crab, Carcinus maenas, and subsequently isolated from Locusta migratoria and Manduca sexta. This is additional evidence that CCAP has widespread occurrence in arthropoda.