Nesidioblastosis associated with hyperglycemia in two squirrel monkeys (Saimiri sciureus)

Abstract: Nesidioblastosis associated with progressive weight loss and hyperglycemia was diagnosed in two mid-adult, wild-caught, male squirrel monkeys (Saimiri sciureus). Hyperglycemia, glucosuria, and abnormal glucose tolerance test results were found when the monkeys were presented for clinical evaluation for chronic weight loss, episodic dehydration, hypothermia, and lethargy. Immunohistochemical studies of the pancreatic tissue demonstrated that the proliferating endocrine cells stained predominantly glucagon-positive in the most severely affected monkey.     

In Situ Analyses of Methane Oxidation Associated with the Roots and Rhizomes of a Bur Reed, Sparganium eurycarpum, in a Maine Wetland

Methane oxidation associated with the belowground tissues of a common aquatic macrophyte, the burweed Sparganium eurycarpum, was assayed in situ by a chamber technique with acetylene or methyl fluoride as a methanotrophic inhibitor at a headspace concentration of 3 to 4%. Acetylene and methyl fluoride inhibited both methane oxidation and peat methanogenesis. However, inhibition of methanogenesis resulted in no obvious short-term effect on methane fluxes. Since neither inhibitor adversely affected plant metabolism and both inhibited methanotrophy equally well, acetylene was employed for routine assays because of its low cost and ease of use. Root-associated methanotrophy consumed a variable but significant fraction of the total potential methane flux; values varied between 1 and 58% (mean (plusmn) standard deviation, 27.0% (plusmn) 6.0%) with no consistent temporal or spatial pattern during late summer. The absolute amount of methane oxidized was not correlated with the total potential methane flux; this suggested that parameters other than methane availability (e.g., oxygen availability) controlled the rates of methane oxidation. Estimates of diffusive methane flux and oxidation at the peat surface indicated that methane emission occurred primarily through aboveground plant tissues; the absolute magnitude of methane oxidation was also greater in association with roots than at the peat surface. However, the relative extent of oxidation was greater at the latter locus.     

An impedimetric method for rapid screening of cosmetic preservatives

An efficient impedance method was developed for rapid evaluation of cosmetic preservatives. The method used decimal reduction time or D-value to assess preservative efficacies. The D-value, which was calculated from the plot of Log CFU ml^–1 versus time by linear regression analysis, could be obtained within 48 h. Thus, the time required for the challenge test was reduced from 4–8 weeks with the standard procedures (eg US Pharmacopeia), to 2 days with the current method. A calibration curve (r=-0.95) was established by plotting the Log CFU ml^–1 versus capacitance detection time (DT) of 108 samples. With the calibration, CFU can be estimated directly from the impedance test without plating. Two commercial biocides and several other chemicals were evaluated in a shampoo by the impedance procedure againstPseudomonas aeruginosa. The D-values obtained from the impedance test were not significantly different from those produced by the conventional plate count method. The technique was found to be particularly useful when screening a large number of compounds to find novel preservatives and synergistic preservative combinations.     

Subject: Endocrinology and chronobiology

Research Notes on Avian Biology 1994: Selected Contributions from the 21st International Ornithological CongressMorphology and Physiology: Endocrinology

Subject: Endocrinology and chronobiology     

Allozyme differentiation within and between red drum (Sciaenops ocellatus) from the Gulf of Mexico and Atlantic Ocean

Nine polymorphic nuclear-gene (allozyme) loci were surveyed among 491 red drum ( Sciaenops ocellatus ) sampled in 1988 and 1989 from nearshore localities in the northern Gulf of Mexico (Gulf) and the Atlantic coast of the southeastern United States (Atlantic). Data were combined with those from a previous study to generate a data set of 762 individuals representing 11 sample localities in the Gulf and 175 individuals representing five sample localities in the Atlantic. The combined data set included individuals from the 1986 and 1987 year classes and permitted rigorous testing of both temporal and spatial genetic heterogeneity. Average heterozygosity-per-locus values (estimated using 33 assumed monomorphic loci) were 0·048 (Gulf red drum) and 0·046 (Atlantic red drum). Tests of heterogeneity in allele frequencies between year classes at individual localities and across regions (Gulf and Atlantic) were non-significant. Tests of spatial (geographic) heterogeneity indicated that red drum are weakly subdivided: genetically-differentiated subpopulations occur in the northern Gulf and along the south-eastern Atlantic coast. Genetic data were consistent with the hypothesis that red drum within the Gulf and along the Atlantic coast comprise singie subpopulalions. Genetic differences between Gulf and Atlantic red drum seem likeiy to stem from historical or recent interactions between dispersal and impediments to gene flow.     

Restriction enzymes in cells, not eppendorfs

Restriction enzymes are essential reagents to molecular biologists, but their relevance to bacterial populations is less obvious. Most bacteria encode restriction and modification systems and these are commonly considered to be a barrier to phage infection. Current evidence also supports a more general role for them in genetic recombination.     

The effects of early experience on adult copulatory behavior in zoo-born chimpanzees (Pan troglodytes)

This paper examines the relationship between the early rearing experience of zoo-born, zoo-reared chimpanzees (Pan troglodytes) and the subsequent occurrence of successful copulation as adults. Developmental histories were acquired for 71 subjects via questionnaires and phone interviews. The following variables related to aspects of chimpanzees' early rearing experience were examined: (1) Rearing conditions, that is, hand reared alone, reared with siblings or peers, or reared by at least one adult conspecific. (2) Age removed from mother. (3) Sex of subject, and/or (4) participation in shows. Each of these variables was then compared to the subjects' sexual competence, defined here as having been observed to exhibit functional copulatory behavior as adults. Seventy-five percent of the subjects were observed to exhibit functional copulatory behavior on at least one occasion. No single component of rearing was successful in producing sexually competent adults 100% of the time; no rearing condition, as defined in this study, resulted in reproductive failure for all subjects experiencing those conditions. Chimpanzees that were hand reared alone, that is, in the total absence of conspecifics, were least likely to copulate as adults; about half of those chimpanzees that were reared with siblings or peers (and in the absence of adult conspecifics) copulated as adults. Almost 90% of those chimpanzees that were reared with at least one adult conspecific copulated as adults. Chimpanzees removed from their mothers at an early age (less than one year of age) were less likely to reproduce as adults. Male and female chimpanzees were equally likely to reproduce as adults. Participation in shows or demonstrations appeared to have no effect on chimpanzees' ability to copulate as adults. © 1994 Wiley-Liss, Inc.     

Detection of interchromosomal translocations within the Triticeae by RFLP analysis.

Twenty-three wheat/alien addition or substitution lines were screened using restriction fragment length polymorphisms for the presence or absence of 4/5 and 4/7 reciprocal translocations in the alien chromosomes. Such translocations have previously been identified in wheat and rye. Group 4 and group 5 Aegilops umbellulata, Triticum urartu, and Thinopyrum bessarabicum chromosomes were found to carry 4/5 translocations. Evidence for a 4/7 translocation was also found in Secale montanum. The presence of the 4/5 translocations in T. urartu indicates that the translocation predates the polyploidization of wheat. The implications of these results are discussed.     

Detection of ribosomal DNA sites in lentil and chickpea by fluorescent in situ hybridization.

Hybridization sites of an rDNA probe coding for the 18S, 5.8S, and 26S genes were detected on lentil and chickpea somatic chromosomes using fluorescent in situ hybridization. One pair of hybridization sites was detected in cultivated lentil Lens culinaris L. and wild lentil L. orientalis (Boiss.) Hand.-Mazz., and in both the hybridization sites of the ribosomal probe correspond to the secondary constriction. In cultivated chickpea Cicer arietinum three pairs of rDNA sites were detected and in the wild C. reticulatum two pairs were detected. The karyotypic relationship between the cultivated C. arietinum and its wild progenitor C. reticulatum is discussed.     

The genetic characterisation of novel multi-addition doubled haploid lines derived from triticale x wheat hybrids

Two novel 46-chromosome doubled haploid lines, W66 and M17, derived from separate hexaploid triticale x bread wheat crosses, were characterised using cytological and biochemical markers. Both lines were shown to be relatively stable cytologically, over 11 and 8 generations of selfing, respectively. By examining mitotic and meiotic chromosomes, the stabilities of the two lines were shown to be similar with frequencies of 2n=46 in 74.2–85.5% of cells. However, over selfed generations, the rye chromosomes were shown to have lost some of their heterochromatin, which made it difficult to establish their continued presence using cytological techniques, such as C-banding alone. Cytological evidence from pairing studies, C-banding, and fluorescence in-situ hybridization, showed that both M17 and W66 are wheat/rye multi-addition lines with rye chromosome constitutions of 1R+6R, and 1R+4R, respectively. These conclusions were confirmed by isozyme and storage-protein analysis.