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Biomedical subjects

P Osborne

Publications and source records attributed to P Osborne.

13 recordsLinked to original sources
PubMed1992

The influence of growth hormone on cell proliferation in odontogenic epithelia by bromodeoxyuridine immunocytochemistry and morphometry in the Lewis dwarf rat.

For investigation of how growth hormone affects tooth development, bromodeoxyuridine immunocytochemistry and morphometry were used for the study of cell proliferation in odontogenic epithelial cell layers. The number of cells in the S phase, as revealed by this technique, and in mitosis, were counted in Bouin's-perfused and paraffin-embedded undecalcified maxillary incisor enamel organs of normal rats, in growth-hormone-deficient dwarf rats, and in dwarf rats treated with growth hormone (66 micrograms/100 g body wt) twice daily for six days. Significantly fewer labeled nuclei, unlabeled nuclei, and total nuclei of various odontogenic epithelia were found in dwarf rats, but in dwarf rats treated with growth hormone, numbers of labeled nuclei equivalent to normal were found in the internal enamel epithelium, stratum intermedium, and Hertwig root sheath. Moreover, the mitotic index for pre-ameloblasts was 1.64 in normal rats, 0.92 for dwarf rats, and 1.66 for growth-hormone-treated dwarf rats (SD, 0.10). Other parameters--such as the labeling index and the ratio of positive to negative nuclei--were similarly related to GH status. Thus, growth hormone may play a role in the proliferation of the odontogenic epithelia in the rat.

Ameloblasts↗
PubMed1988

Na deficiency and other physiological influences on voluntary Na intake of BALB/c mice.

BALB/c mice exhibited a small hedonic intake of 0.3 M NaCl, which was not influenced by change from high to low salt diet or by withholding access to NaCl solution for 1 day. Sodium deficiency produced by furosemide injection consistently caused a highly significant increase in sodium intake. Sodium deficiency was corrected rapidly over 10 min. The appetite was specific for sodium in a cafeteria experiment and was exhibited by naive animals on the first experience of sodium deficiency and subsequent access to salt. The appetite was significantly related to the extent of body deficit, but overdrinking proportionate to initial deficit was characteristic. No increase in sodium intake occurred with repeated experience of sodium deficit. Water deprivation caused a subsequent increase of sodium intake. Total deprivation of food for 48 h caused a large sustained increase of sodium intake, but reduction of food intake by 40% did not influence sodium appetite.

Animals↗
PubMed1986

A pharmacological and immunohistochemical study of the splanchnic innervation of ileal longitudinal muscle in the toad Bufo marinus.

A study was made of the innervation of the longitudinal muscle of the toad ileum with particular emphasis on the splanchnic innervation by non-adrenergic, non-cholinergic (NANC) nerves. Nerve fibres containing substance P-like immunoreactivity (SP-LI) were observed in the gut wall and in the ileal wall after degenerative section of the splanchnic nerves. Incubation overnight in a high concentration of capsaicin (3 X 10(-4) M) caused degeneration of SP-LI fibres. No evidence was obtained for enteric neurons containing SP-LI. Substance P caused a contraction of the longitudinal muscle similar to that produced by nerve stimulation. The response to nerve stimulation was decreased by about 60% by treatment with alpha-chymotrypsin. Capsaicin normally evoked a contraction of the longitudinal muscle, but did not do so after degenerative section of the splanchnic nerves. Prolonged treatments with high concentrations of capsaicin (5 X 10(-5) M) abolished the excitatory response to nerve stimulation. The results suggest that substance P is the transmitter mediating the NANC contraction. The fibres releasing the transmitter are possibly antidromically activated, sensory afferents. Both transmural stimulation and capsaicin caused a NANC inhibition of longitudinal muscle. Stimulation of perivascular nerves after splanchnic nerve section caused a NANC excitation, as did transmural stimulation even after nerve section or capsaicin treatment.

Animals↗
PubMedDate not supplied

Spontaneous rupture of an iliac vein.

A 67 year old female was seen as an emergency some three days following a minor fall with spontaneous rupture of the left iliac vein. Emergency surgery consisted of repair of the venous rent, compartmentation of the vena cava, thrombectomy, and subsequently anticoagulation. Etiology of the rupture was considered to be the thrombosis in the proximal portion of the iliac vein which created a high venous pressure behind the thrombus.

Aged↗
PubMedDate not supplied

Histocompatability antigens in the fibrositis (fibromyalgia) syndrome.

HLA antigen Class I (A, B, C) and II (DR) were determined in a small group of fibrositis (fibromyalgia) patients and normal controls. Sixty-seven percent of fibrositis patients had DR4 versus 30% of normal controls. There was also an increased relative risk (4.5). No statitical significance of other Class I and II antigens in fibrositis was found.

Adult↗