Receptive field integration and submodality convergence in the hand area of the post-central gyrus of the alert monkey. (49/4345)

1. An exploration of the occurrence of different functional cell types was made in the three cytoarchitectural subdivisions (areas 3, 1 and 2) of the hand area of the post-central gyrus of the monkey. The functional properties of 632 cells were studied using the transdural micro-electrode recording method. 2. Over half of the neurones studied (57%) belonged to the class of simple skin neurones that were related either to rapidly adapting (272 neurones) or slowly adapting (seventeen neurones) cutaneous receptors or to both (seventy-one neurones). The simple skin neurones were particularly common in the anterior part of S I where they constituted 60% of the cells. More complicated cutaneous neurones made up 10% of the total sample. They were more common in the posterior part of the gyrus. 3. Altogether ninety-two neurones (15%) were related to subcutaneous or deeper receptors. Another seventy-one neurones (11%) exhibited convergence of skin input and input from deep receptors. A smaller group of forty-seven undamaged neurones (7%) were unrelated to stimuli of the types described above. 4. In tangential electrode penetrations made along the anterior and posterior banks of the gyrus, functional columns were found to be 500 micrometers wide on the average; this width is comparable with that of ocular dominance columns and visual orientation hypercolumns. 5. Correlation of the functional types of cells with cytoarchitecture showed that the complexity of the functional properties of the neurones increased posteriorly. The receptive field size also increased toward posterior. The changes that take place in the functional properties of cells when moving across different cytoarchitectural areas suggests intracortical information processing which leads to handling of larger body regions and more complex combinations of information in the cellular elements of the posterior part of the post-central gyrus.  (+info)

A stimulatory effect of the fluid from preimplantation rabbit blastocysts upon luteinization of monkey granulosa cell cultures. (50/4345)

Blastocyst fluid was aspirated from Day 6 1/2--7 rabbit blastocysts and was added to cultures of granulosa cells obtained from preovulatory follicles of untreated rhesus monkeys or from follicles of monkeys or from follicles of monkeys treated with PMSG. The stimulation of progesterone secretion was measured and equated with that produced by hCG. The hCG-like activity was also measured in a radioreceptor assay using 125I-labelled hCG and porcine granulosa cells. In 8 out of 10 experiments with cultured cells from untreated monkeys, addition of 20% blastocyst fluid from Days 6--9 of culture stimulated progesterone secretion by 2- to 6-fold. Similar findings were obtained in 5 experiments with cultures from PMSG-treated monkeys except that the blastocyst fluid was added from Days 0 to 6 of culture. The granulosa cells in such cultures underwent morphological luteinization. Compared to a standard of purified hCG the blastocyst fluid contained about 0.76--2.5 ng hCG-like activity/ml which was non-dialysable. The radioreceptor assay indicated the presence of 0.5--2.5 ng hCG-like material/ml.  (+info)

Administration of extra-amniotic arachidonic acid and the suppression of uterine prostaglandin synthesis during pregnancy in the rhesus monkey. (51/4345)

After extra-amniotic treatment of pregnant rhesus monkeys premature parturition was induced in 4 given 2.5 mg PGE-2; none of the 4 monkeys given 100 mg arachidonic acid were affected. The concentrations of PGE, PGF, or 13,14-dihydro-15-oxo-PGF did not change after arachidonic acid treatment, but all increased after PGE-2. It is suggested that the availability of substrate, arachidonic acid, is not a major factor governing the control of PG synthesis but that the latter is suppressed during pregnancy.  (+info)

Studies of the specificity of ureaplasmas for marmosets. (52/4345)

Marmosets, from which endogenous ureaplasmas had been eradicated by treatment with minocycline, were tested for susceptibility to infection by ureaplasmas from the genital and respiratory tracts of other animal species. They could be infected with ureaplasmas of human and simian origin, but were resistant to bovine and canine ureaplasmas. The results indicated that human, marmoset and squirrel-monkey ureaplasmas may form a biological subgroup, distinct from bovine and canine ureaplasmas, and that host range should not be ignored as a parameter for classification.  (+info)

Creutzfeldt--Jakob disease. (53/4345)

The laboratory transmission to animals of an apparently degenerative disease of the nervous system, Creutzfeldt-Jakob disease (CJD), is now well established. Important questions arising from this observation are the possibility of natural transmission or infectivity and the existence of other similarly transmissible diseases. Epidemiological studies have revealed some possible clusters of CJD and also an association with previous craniotomy, but there is no definite evidence of natural infection. A few instances have been reported of experimental CJD in animals following inoculation with material from Alzheimer's disease, but apart from this there is so far no evidence of transmission of any other form of degenerative nervous disease.  (+info)

Immunization against malaria with antigen from Plasmodium falciparum cultivated in vitro. (54/4345)

Aotus monkeys, which are generally killed when infected with the human malaria parasite Plasmodium falciparum, have been identified and grouped by karyotype. These animals were immunized with parasite material obtained from P. falciparum cultivated in vitro which had been maintained in culture for over a year. When sufficient amounts of this antigenic material were used with a synthetic muramyl dipeptide (MDP), protective immunity was induced without presenting the antigen in complete Freund's adjuvant.  (+info)

Histochemically distinct compartments in the striatum of human, monkeys, and cat demonstrated by acetylthiocholinesterase staining. (55/4345)

We here report observations on the distribution of acetylcholinesterase (acetylcholine hydrolase, EC in the striatum of the adult human, the rhesus monkey, and the cat. By the histochemical staining methods of Geneser-Jensen and Blackstad and of Karnovsky and Roots, compartments of low cholinesterase activity were identified in parts of the striatum in all three species. In frontal sections, these enzyme-poor zones appeared as a variable number of weakly stained approximately 0.5-mm-wide zones embedded in a darkly stained background. The zones varied in cross-sectional shape from round to elongated and were sometimes branched. They were most prominent in the head of the caudate nucleus. Three-dimensional reconstructions of serial sections through the caudate nucleus in the human and cat suggest that over distances of at least several millimeters, the zones of low enzyme activity form nearly continuous labyrinths.  (+info)

Characterization of Bacteroides forsythus strains from cat and dog bite wounds in humans and comparison with monkey and human oral strains. (56/4345)

Bacteroides forsythus strains recovered from cat and dog bite wound infections in humans (n = 3), monkey oral strains (n = 3), and the human oral ATCC 43037 type strain were characterized by using phenotypic characteristics, enzymatic tests, whole cell fatty acid analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, PCR fingerprinting, and 16S rDNA (genes coding for rRNA) sequencing. All three bite wound isolates grew on brucella agar supplemented with 5% sheep blood, vitamin K1, and hemin. These strains, unlike the ATCC strain and previously described monkey oral and human clinical strains, did not require N-acetylmuramic acid supplementation for growth as pure cultures. However, their phenotypic characteristics, except for catalase production, were similar to those of previously identified strains. PCR fingerprinting analysis showed differences in band patterns from the ATCC strain. Also, SDS-PAGE and whole cell fatty acid analysis indicated that the dog and cat bite wound strains were similar but not identical to the human B. forsythus ATCC 43037 type strain and the monkey oral strains. The rDNA sequence analysis indicated that the three bite wound isolates had 99.93% homology with each other and 98.9 and 99.22% homology with the human ATCC 43037 and monkey oral strains, respectively. These results suggest that there are host-specific variations within each group.  (+info)