The readers' NIH.
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Biological Science Disciplines↗
Biomedical subjects
T Frederick
Publications and source records attributed to T Frederick.
Frequency of twinning in paediatric HIV infection.
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Acquired Immunodeficiency Syndrome↗
CD4 T-lymphocyte counts and Pneumocystis carinii pneumonia in pediatric HIV infection.
The relationship between CD4 T-lymphocyte counts and infection with the human immunodeficiency virus (HIV) is retrospectively investigated for 266 HIV-infected and uninfected children who were born to infected women, including 39 with Pneumocystis carinii pneumonia (PCP), in a population-based surveillance study. Of 21 perinatally HIV-infected children with PCP only 10 (48%) had CD4 T-lymphocyte counts that were less than 500 x 10(6) cells/L (500 cells/mm3), compared with all 18 who were infected via blood transfusions or clotting factors. Among 68 children who were 1 year or younger, 18 (90%) of 20 PCP cases had CD4 T-lymphocyte counts that were less than 1500 x 10(6) cells/L (1500 cells/mm3) compared with only five (10%) of 48 children who did not have the acquired immunodeficiency syndrome (odds ratio, 77.4; 95% confidence interval, 19.7 to 313.4). The mean CD4 T-lymphocyte count was lower for the 39 PCP cases when compared with the 188 children who were at different stages of HIV infection and did not have the acquired immunodeficiency syndrome (AIDS) independent of age. The majority of perinatally HIV-infected children with PCP were 6 months or younger and 50% were previously unknown to be infected. Thus, HIV-positive children should be identified early and followed closely. CD4 T-lymphocyte counts may be useful in monitoring HIV-positive children and determining when to begin PCP prophylaxis.
Acquired Immunodeficiency Syndrome↗
Citric acid treatment of periodontitis-affected cementum. A scanning electron microscopic study.
Previous studies have described an inconsistent histological occurrence of a zone of surface demineralization on periodontitis-affected cementum following treatment with citric acid, and a lack of connective tissue attachment to the latter surfaces. In view of these findings, the purpose of the present study was to use scanning electron microscopy to examine the surface morphology of cementum from normal and periodontitis-affected root surfaces following citric acid treatment for differences in the effects of the demineralizing solution on these surfaces. Cementum surfaces were derived from the roots of extracted human teeth from areas beneath attached periodontal ligament fibers (normal) and calculus deposits (periodontitis-affected). 5 specimens were evaluated in both groups. Periodontal ligament fibers were removed from normal root surfaces with a curette, and calculus deposits were removed from periodontitis-affected root surfaces using an ultrasonic scaler. The resultant 5 specimens in each group were then sectioned in half, one-half serving as the untreated control and the other as the experimental, citric acid treated specimen. Experimental specimens were immersed in a saturated solution of citric acid, pH 1 for 3 min and then rinsed in tap water. Both control and experimental specimens were dehydrated in ethanol, critical-point dried, sputter-coated with gold and examined in the scanning electron microscope for morphological characteristics. Citric acid treatment of cementum from normal root surfaces produced an undulating, markedly fibrillar surface morphology which is consistent with the exposure of a fibrillar, collagen substrate. Periodontitis-affected cementum, however, was not appreciably altered in appearance by the citric acid treatment, having only a faint mat-like surface texture. (ABSTRACT TRUNCATED AT 250 WORDS)
Citrates↗
Passive immunity in transmissible gastroenteritis of swine: intramuscular injection of pregnant swine with a modified live-virus vaccine.
Nine pregnant swine were intramuscularly injected with a modified live-virus transmissible gastroenteritis (TGE) vaccine at approximately 6 and 2 weeks before parturition. The TGE antibody levels in milk whey rapidly decreased within a few days after parturition, and the antibodies were mainly, if not solely, of the immunoglobulin G (IgG) class. Nursing newborn pigs were challenge exposed with virulent TGE virus when 2 to 4 days old. All pigs in 8 of the 9 litters became affected with typical signs of TGE. Of the pigs nursing vaccinated sows, 55% died, and of the 9 vaccinated sows, 8 became affected after challenge exposure of their litters. Subsequently, the antibody titers in serum and milk markedly increased in all 9 sows, with the antibody in milk being predominantly of the immunoglobulin A (IgA) class. Serum samples of prenursing newborn pigs from vaccinated sows did not contain detectable TGE antibodies. The capability of the vaccinated sows to provide only limited passive immunity to their suckling pigs was considered to be due mainly to the low titer and class (IgG) of TGE antibody existing in the milk of the sows at the time the newborn pigs were challenge exposed.
Animals↗