Biomedical subjects
N King
Publications and source records attributed to N King.
The effect of in ovo boron supplementation on bone mineralization of the vitamin D-deficient chicken embryo.
It has been hypothesized that boron (B) is an essential element for animals, but its action will vary greatly depending on the nutriture of the organism. One of the nutrients implicated as having an interaction with boron is cholecalciferol (Vit D3). This study was carried out to determine if such an interaction exists. The study was conducted utilizing vitamin D-deficient chicken embryos that were injected through the shell at 8 d of embryogenesis with carrier (NaCl and/or acetone), B (0.5 mg), B + Vit D3 (0.5 mg and 0.3 microgram, respectively), or Vit D3 (0.3 or 1.5 micrograms). The in ovo concomitant administration of boron and vitamin D enhanced (p less than 0.05) the hatchability of the vitamin D-deficient embryos. Furthermore, boron and/or vitamin D3 increased (p less than 0.05) the percent of bone ash and decreased (p less than 0.05) the exaggerated height of the proliferative zone of the epiphyseal growth plate normally observed in vitamin D deficiency, suggesting a more rapid bone formation. The results provide further evidence supporting the hypothesis that boron plays a role in bone mineralization through an interaction with vitamin D.
In ovo administration of boron alters bone mineralization of the chicken embryo.
It has been hypothesized that boron (B) is an essential element for animals, especially in bone metabolism. In this study, the influence of in ovo boron administration was assessed in the chicken. At 8 d of embryogenesis, carrier or B (0.1, 0.5, or 1.0 mg) was injected on to the chorioallantoic membrane of fertile eggs. At hatching, body weights were recorded and tissue samples collected. Although boron failed to alter bone mineralization, it decreased (p less than 0.05) dried bone weight, suggesting a reduction in the bone organic matrix. Furthermore, 1 mg boron decreased (p less than 0.05) hatchability and increased (p less than 0.05) the height of the proliferative zone in the growth plate, indicating an unfavorable effect on bone elongation of the developing chick.
Lactic acid recovery profiles following exhaustive arm exercise on a canoeing ergometer.
In this study lactate removal rates were monitored in ten subjects during a 30-min recovery period following exhaustive arm exercise. Each subject experienced three recovery regimens on different occasions in random order. One recovery period consisted of supine rest while the other two were active, one incorporating low intensity arm exercise and the other consisting of low intensity leg exercise. Lactate clearance rates showed a significant difference between the recovery regimens, and a posteriori test indicated a significant difference between leg exercise and arm exercise in the recovery period and also between leg exercise and rest. There was no significant difference in lactate clearance between arm exercise and rest in the recovery period.
Induction of AIDS in rhesus monkeys by molecularly cloned simian immunodeficiency virus.
Better understanding of the pathogenesis of acquired immunodeficiency syndrome (AIDS) would be greatly facilitated by a relevant animal model that uses molecularly cloned virus of defined sequence to induce the disease. Such a system would also be of great value for AIDS vaccine research. An infectious molecular clone of simian immunodeficiency virus (SIV) was identified that induces AIDS in common rhesus monkeys in a time frame suitable for laboratory investigation. These results provide another strong link in the chain of evidence for the viral etiology of AIDS. More importantly, they define a system for molecular dissection of the determinants of AIDS pathogenesis.
Emotive imagery and children's night-time fears: a multiple baseline design evaluation.
Emotive imagery is a variant of systematic desensitization that has been used in the treatment of children's excessive fears. The purpose of this study was to evaluate the efficacy of emotive imagery as a fear reduction procedure using a multiple baseline design across subjects. Three children (6, 8 and 11 years old) with night-time fears participated in the study. The children showed marked behavioral improvements on a test for darkness toleration that was administered on alternate days in their homes. However, they reported experiencing very little fear in these tests. Over the intervention period fewer night-time behavioral disturbances were observed for two subjects. Parents expressed some concern about the darkness test but were satisfied with emotive imagery as a fear reduction procedure. As children's phobias are characterized by multiple processes, we recommend a combination of treatment procedures in clinical practice.
Flavivirus infection up-regulates the expression of class I and class II major histocompatibility antigens on and enhances T cell recognition of astrocytes in vitro.
West Nile virus (WNV) infection of astrocytes can up-regulate their expression of both class I and class II major histocompatibility complex (MHC) antigens as determined by flow cytometry with monoclonal antibodies specific for class I and class II MHC antigens. The up-regulation of class I MHC antigen expression could be partly caused by interferon secreted after WNV infection because the synthetic interferon inducer polyinosinic-polycytidylic acid (poly I:C) has similar effects. In contrast the up-regulation of class II MHC antigen expression was not induced by poly I:C. The increased MHC antigen expression by WNV infection had significant effects on T cell recognition. Thus, WNV and influenza virus A/WSN double-infected astrocytes but not astrocytes infected by A/WSN alone were lysed by influenza virus-immune cytotoxic T cells. Similarly, WNV-infected astrocytes were better stimulators than normal astrocytes for a class II MHC-reactive T cell line, both in terms of T cell proliferation and interleukin release.
Differential effects of acute endotoxin shock on myocardial contractility and performance.
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West Nile virus infection modulates the expression of class I and class II MHC antigens on astrocytes in vitro.
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Characterization of colonic cellular glycoconjugates in colitis and cancer-prone tamarins versus colitis and cancer-resistant primates.
Differences in colonic secretory glycoconjugates (ie, mucin) between normal and ulcerative colitis-prone patients have been noted. Similar differences may occur in a corresponding primate model, the cotton-top tamarin (CTT), Saguinus oedipus, a New World monkey which suffers from spontaneous chronic colitis and colon cancer. Lectin reagents were used to characterize and compare colonic cell surface, cytoplasmic, and secretory glycoconjugates of 9 clinically healthy cotton-top tamarins, 7 colitis-susceptible, cancer-resistant tamarins (Callithrix jacchus, Saguinus fuscicollis), and 8 colitis and cancer-resistant primates (Aotus trivirgatus, Saimiri sciureus, Macaca fascicularis, and Macaca mulatta). Paraffin-embedded colonic sections were labeled with ten different biotinylated lectins and visualized by the avidin-biotin peroxidase (ABC) method. Significant differences were demonstrated in the pattern of lectin staining between the colitis-resistant and colitis-prone groups of primates. The differences were noted with Griffonia simplicifolia-I (GS-I), Dolichos biflorus agglutinin (DBA), peanut agglutinin (PNA) before and after neuraminidase, Ricinus communis agglutinin-I (RCA-I), soybean agglutinin (SBA), Ulex europaeus agglutinin-I (UEA-I), wheat germ agglutinin (WGA), and succinylated WGA (S-WGA). Significant differences between the CTT and phylogenetically related colitis-prone but cancer-resistant tamarins were demonstrated with SBA, UEA-I, and PNA after desialylation with neuraminidase. These results suggest that differences in colonic cellular glycoconjugates between colitis- and cancer-susceptible species versus colitis-susceptible, cancer-resistant species may be associated with risk of cancer.
Differences in cellular glycoconjugates of quiescent, inflamed, and neoplastic colonic epithelium in colitis and cancer-prone tamarins.
In the preceding paper the authors demonstrated that the lectin staining patterns of normal colonic epithelium obtained from colitis and carcinoma-prone cotton top tamarins (CTTs), Saguinus oedipus, a New World primate, differs from colitis- and carcinoma-resistant primate species. In this study they determined the usefulness of cytochemical features in inflamed epithelium as indicators for malignant change. They compared the lectin staining pattern in inflamed mucosa and adjacent mucosa with colonic carcinoma from 8 CTTs with that of 9 clinically healthy CTTs with no histologic evidence of colitis. Deparaffinized sections were labeled with ten biotinylated lectins and stained by the avidin-biotin peroxidase complex method. Numerous significant differences were demonstrated in the lectin staining pattern between normal epithelium and colonic carcinoma; fewer between normal and chronic inflamed epithelium. However, between chronic inflamed epithelium and colonic carcinoma significant staining differences were observed with only two lectins, peanut agglutinin (PNA) and Ulex europaeus agglutinin-I (UEA-I). These findings suggest that there is a progression in alteration of lectin staining pattern from normal epithelium, via chronic colitis, to colonic carcinoma. Furthermore, the differences between chronic colitis and colonic carcinoma are expressed only with those lectins that are associated with malignant transformation of human colonic epithelium.
Society of Practising Veterinary Surgeons.
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Trace mineral supplementation of burn patients: a national survey.
Much research effort has been devoted to determination of caloric and protein requirements in burn patients. Although it is generally accepted that trace mineral requirements increase concomitantly with caloric and protein needs, little research has been conducted to document that assumption. Our survey was undertaken to assess current practice and identify research needs. One hundred ninety-six survey questionnaires were sent to burn units in North America. Forty percent (78) were returned. Ninety percent of respondents prescribe or recommend trace mineral supplements in their facilities. "Higher risk" was the single criterion most often mentioned as a basis for supplementation (54 [77%] of 70 respondents), with 49 of them indicating that they provide trace mineral supplements to patients receiving total parenteral nutrition support. Fifty-six respondents provided detailed information concerning trace mineral supplementation. Of that group, 88% prescribe zinc supplements, 75% prescribe iron supplements, and 26% prescribe chromium supplements. Thirteen percent supplement selenium. Less than 2% supplement molybdenum or vanadium and do so only when administering total parenteral nutrition. Many respondents expressed concern about the lack of guidelines for trace mineral supplementation in the burn patient, leading to the conclusion that further research in that area would benefit burn-injured patients and the health care providers who care for them.
The extracellular matrix of Volvox: a comparative study and proposed system of nomenclature.
The structure of the extracellular matrix (ECM) of representatives of all four sections of the genus Volvox was examined by a combination of light- and electron-microscopic methods. On the basis of these observations, plus published descriptions of aspects of ECM organization in other members of the order Volvocales, a system of nomenclature is proposed, to facilitate discussion of comparative morphology and phylogeny of the ECM in the order. In this system the ECM is divided into four main zones: the flagellar zone (FZ), which consists of attachments to and specializations of the ECM around the flagella; the boundary zone (BZ), which consists of portions of the ECM that (except in periflagellar regions) are continuous over the surface of the organism and are not structurally continuous with deeper layers; the cellular zone (CZ), which consists of specializations, other than those of the FZ, around individual cells; and the deep zone (DZ), which consists of components that fill the central region of the organism, internal to CZ. An empirically based set of hierarchical subdivisions of these zones is then proposed that permits specific identification of most morphologically distinct ECM components. The fact that not all zones and subzones are present in all members of the order means that this system permits identification of those ECM structures that have been gained or lost during Volvocalean evolution. Species-specific differences in the structure of virtually all aspects of the ECM were seen among the Volvox species examined in this study. However, the fact that such differences cannot always be used as diagnostic characters for the four divisions of the genus was demonstrated by the observation that in certain ECM features two members of the same division (V. carteri f. nagariensis and V. carteri f. weismannia) differ markedly in structure from one another, with one member of the pair resembling a member of another division. Thus many details of ECM organization appear to be under separate control, and capable of independent evolution.
C.T. demonstration of retroperitoneal hematoma caused by high inguinal arterial puncture during angiography.
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Veterinary manpower requirements.
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Colonic mucin composition in primates. Selective alterations associated with spontaneous colitis in the cotton-top tamarin.
Heterogeneity of colonic mucin glycoprotein was examined in rectal mucosal biopsy specimens from a variety of primate species (Saguinus oedipus, n = 18; Macaca mulatta, n = 2; Macaca fascicularis, n = 2; Aotus trivirgatus, n = 2; Saimiri sciureus, n = 2; and Callithrix jacchus, n = 2). After initial separation of radiolabeled mucin and nonmucin glycoproteins solubilized from mucosal biopsy specimens, at least five labeled mucin components were found in monkey rectal mucosa in contrast to the six mucin fractions observed in the human colon. Although primates consistently lacked the earliest eluting component present in human colonic mucin, other mucin components cochromatographed with comparable fractions previously identified in human colonic biopsy specimens. The relative proportions of each fraction were consistent throughout all species except the cotton-top tamarin (S. oedipus), an animal that develops a chronic colitis. The cotton-top tamarin was found to have a markedly reduced amount of one mucin component (IV) in a manner analogous to the reduction in a human mucin fraction previously noted in patients with ulcerative colitis. Sequential evaluation of mucin profiles in cotton-top tamarins (n = 12) treated with sulfasalazine (50 mg/kg X day) or placebo in a 10-wk double-blind crossover study demonstrated the persistence of the selective reduction in tamarin species IV unrelated to disease activity. In contrast, the relative amount of tamarin mucin III was greater in association with increased disease activity than that observed in association with reduced disease activity (46% +/- 11% total mucin vs. 19% +/- 7% total mucin posttreatment).