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Biomedical subjects

C Blackwell

Publications and source records attributed to C Blackwell.

27 records · Page 2Linked to original sources

The effect of Mycoplasma arthritidis infection on the phagocytic activity of macrophages in rats and mice.

The phagocytic activity of mononuclear phagocytes of A/J mice and Wistar rats was estimated by the carbon clearance test following injection of Mycoplasma arthritidis. In mice, the overall phagocytic activity was significantly increased at the end of the first week (P less than 0.0001), but the increase was marginal by the third and fourth weeks after injection. A significant increase in the relative weight of liver and spleen was observed even when phagocytic activity had returned to levels similar to those of controls (P less than 0.001). In rats, the overall phagocytic activity was significantly increased until the fourth week (P less than 0.00001). There was not, however, an increase in the relative weight of liver and spleen as observed for the mice. The results are discussed in the context of factors contributing to the pathogenic mechanisms responsible for differences in the patterns of arthritis due to mycoplasma observed in mice and rats.

Animals↗

In vitro binding of Helicobacter pylori to human gastric mucin.

The in vitro binding of four Helicobacter pylori strains to human gastric mucin was studied with an enzyme-linked immunosorbent assay. All four strains were found to bind to purified mucin. Neuraminidase treatment and nonspecific oxidation of mucin decreased bacterial adherence to the macromolecule. Mucin preparations were also found to inhibit attachment of H. pylori to HEp-2 monolayers.

Bacterial Adhesion↗

Neuroendocrine dysfunction in sleep apnea: reversal by continuous positive airways pressure therapy.

We studied the effects of sleep apnea on neuroendocrine function in a cross-sectional study of 225 consecutive men undergoing sleep studies and in a longitudinal study of 43 men with severe obstructive sleep apnea before and after 3 months of successful treatment with nasal continuous positive airways pressure to eliminate upper airways obstruction. Blood samples were collected at 0600-0630 h on awakening for measurement of plasma insulin-like growth factor I (IGF-I), total and free testosterone, sex hormone-binding globulin (SHBG), LH, FSH, PRL, T4, T4-binding globulin, and cortisol. The plasma hormone levels were analyzed in relation to the severity of sleep apnea, as indicated by the desaturation index (the hourly rate of episodes of arterial oxygen desaturation greater than 4% of the stable baseline) and the mean minimal oxygen saturation during the desaturation episodes. In the cross-sectional study plasma IGF-I, free and total testosterone, and SHBG levels were significantly lower in relation to the severity of sleep apnea, whereas plasma LH, FSH, PRL, T4, T4-binding globulin, and cortisol were not. The decreases in plasma IGF-I and total and free testosterone were independent of the effects of aging and adiposity by covariance analysis. In the longitudinal study plasma IGF-I, total testosterone, and SHBG, but not free testosterone, significantly increased after 3 months of nasal continuous positive airways pressure treatment. We conclude that sleep apnea causes reversible neuroendocrine dysfunction in men, which is manifested by decreased plasma. IGF-I, testosterone, and SHBG levels. This neuroendocrine dysfunction is related to the severity of the sleep apnea, as indicated by the nadir levels of arterial oxygen desaturation and the rate of desaturation episodes. These hormonal measurements may provide biochemical markers for both the severity of sleep apnea and its response to therapeutic intervention. In addition, sleep apnea may be a previously unrecognized confounder of the neuroendocrine correlates of aging.

Adult↗

Oculomotor-corpus callosum dysplasia.

An infant with congenital bilateral ophthalmoplegia with levator and pupillary sparing is presented. The eyes are fixed in a divergent position with no apparent motility. The baby is otherwise clinically normal and is developing in a normal fashion except for delayed growth pattern. Visual attention is present and he fixates with either eye. Computed tomography demonstrates an associated dysplasia of the corpus callosum and an abnormal ventricular system. Neuroendocrine studies performed at one year of age demonstrate subnormal levels of growth hormone. It is postulated that this represents an embryodysgenesis involving the developing mesencephalic tegmentum (oculomotor nuclei) and the diencephalic lamina reuniens (corpus callosum). It is the first reported case of congenital ophthalmoplegia with corpus callosum dysplasia. The "embryodysgenic" relationship with other forebrain-ocular anomalies has been alluded to and remains speculative.

Adult↗

Serum gamma-glutamyl transpeptidase: its specificity and clinical value.

The clinical import of the serum gamma-glutamyl transpeptidase (GGTP) level was evaluted in 162 prospectively studied patients. GGTP is helpful in determining the origin of alkaline phosphatase (AP); it clearly separates increased AP of bone and placental origin from that of liver origin. The GGTP level closely parallels the AP level in most instances, but it may be more sensitive in detecting liver disease in anicteric patients. The finding of significantly increased GGTP in patients with chronic aggressive hepatitis as compared to normal levels found in chronic persistent hepatitis may provide a prognostic clue in cases of unresolved hepatitis. The apparent specificity and sensitivity of the GGTP test, combined with ease of performance and low expense, make it a valuable addition to the evaluation of a patient with hepatic disease.

Adolescent↗

Isolation of Neisseria meningitidis and Neisseria catarrhalis from the genitourinary tract and anal canal.

During a 12-month period 285 isolates of Neisseria species, other than Neisseria gonorrhoeae, were cultured from patients attending the Department of Venereology, Royal Infirmary, Edinburgh. There were eight patients in whom genitourinary or rectal isolates of Neisseria meningitidis or Neisseria catarrhalis were found. Differences between data from our series and from previous reports are discussed with particular regard to sites routinely cultured in female patients. We also report in vitro inhibition of N. gonorrhoeae by an isolate of N. meningitidis cultured from the cerivx of a patient.

Cervix Uteri↗