Search PubMed⌕ Search

Biomedical subjects

R Carter

Publications and source records attributed to R Carter.

At least 325 records · Page 18Linked to original sources
PubMed1983

Monoclonal antibodies against surface determinants on gametes of Plasmodium gallinaceum block transmission of malaria parasites to mosquitoes.

Monoclonal antibodies (MAb) against gametes of the chicken malaria Plasmodium gallinaceum have been derived. All reacted with the surface of extracellular gametes of the parasite in immunofluorescent antibody reactions and all agglutinated both male and female gametes. In the absence of active complement one mu isotype MAb, la 1-D5, mediated at least 95% suppression of infectivity of the parasites to Aedes aegypti mosquitoes. Individually, MAb of the gamma 1 or gamma 2a isotypes mediated only slight suppression in the absence of active complement. Certain combinations of these MAb, however, suppressed parasite infectivity by 90 to 95%. Suppression of infectivity by the MAb was shown to be mainly due to their effects on the events leading up to or including fertilization. Certain gamma 2a isotype MAb, which otherwise mediated minimal or no suppressive effect, completely abolished infectivity of the parasites if complement was present. No target antigen could be identified by immunoprecipitation of Triton X-100 extracts of surface radioiodinated zygotes or gametes of P. gallinaceum for the mu isotype MAb. All gamma isotype MAb precipitated the same three proteins of 240,000, 56,000, and 54,000 daltons under reducing conditions on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, from extracts of radioiodinated male and female gametes. These surface proteins on gametes of both sexes of P. gallinaceum thus appear to include target antigens of anti-gamete transmission blocking immunity.

Aedes↗
PubMed1982

Effect of conjugated estrogens on vaginal blood flow in surgically menopausal women.

The effect of an intravenous bolus of 25 mg of conjugated estrogen (Premarin) on vaginal blood flow in seven surgically menopausal women was measured by a thermal conductance probe. Electrical power (0.8 W) was supplied to a resistance wire incorporated in the surface of the probe, and its surface temperature was monitored continuously for 30 minutes six times daily for 3 days. The mean temperature difference (delta T) between the heated probe surface and the vagina remained unchanged during a preinjection control day. While there were individual differences in response, analysis of mean delta T during the first day following the injection of the estrogen revealed a significant linear downward trend at delta T, indicating a rise in vaginal blood flow. Delta T plateaued on day 2 and showed a slight rise in the morning of day 3. It may be concluded that estrogen administered in this dose and form markedly increases vaginal blood flow.

Adult↗
PubMed1982

A controlled comparison of two treatments for nocturnal enuresis.

This study assessed change in the frequency of primary nocturnal enuresis as produced by either behavioral conditioning with a urine alarm, pharmacotherapy with imipramine hydrochloride, or assignment to a clinical waiting list. The study also investigated the effect of treatment method and outcome on subjects' level of emotional and behavioral adjustment. An attempt was made to identify pretreatment predictors of treatment outcome and premature withdrawal from the treatment program. The results indicated a significantly more effective outcome for the conditioning approach. Comparison of pre- and post-treatment measures of adjustment provided insufficient evidence to support the hypotheses that either change in the frequency of nighttime wetting or the method of treatment received would influence the subject's level of emotional and behavioral adjustment. The enuresis tolerance scale was found to be a highly significant predictor of early termination from conditioning treatment.

Adolescent↗
PubMed1982

Radioiodination of parasite antigens with 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycoluril (IODOGEN): studies with zygotes of Plasmodium gallinaceum.

The iodinating reagent 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycoluril (IODOGEN) was used to label antigens on zygotes of Plasmodium gallinaceum with parallel studies using lactoperoxidase-catalyzed radioiodination for comparison. Proteins labeled by the IODOGEN method are most probably on the surface of the zygote, as the pattern of labeled proteins analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was very similar to the pattern of lactoperoxidase-labeled proteins. Furthermore, the labeled proteins represented only a subset of the total Coomassie Blue-stained proteins. The radioiodinated zygote proteins were immunoreactive after IODOGEN or lactoperoxidase labeling. The IODOGEN method is technically much more simple than the lactoperoxidase method and does not require the addition of extraneous proteins or H2O2. The advantages of IODOGEN labeling, together with the essential equivalence of results obtained by these two methods, make the IODOGEN method attractive for labeling parasite antigens in general.

Animals↗
PubMed1982

A candidate reference method for uric acid in serum. II. Interlaboratory testing.

We describe the interlaboratory testing of a candidate Reference Method (Part I) for uric acid in serum. The method is based on the ultrasound spectrophotometric quantitation of uric acid before and after incubation with uricase. A comprehensive investigation involving 12 laboratories was organized to document the transferability, intra- and interlaboratory precision, and general reliability of the candidate Reference Method. The interlaboratory CV with this method was about 2 to 6% for uric acid concentrations ranging from 0.12 to 0.60 mmol/L. The results detailed here demonstrate that the method can be successfully duplicated among different laboratories.

Evaluation Studies as Topic↗
PubMed1982

Surgical management of the radiologically identified but nonpalpable pulmonary lesion.

A solitary intrapulmonary nodule may, on rare occasions, be of the same consistency as the pulmonary tissue and therefore not be palpable by the surgeon at operation nor by the pathologist in the removed specimen. The importance of routine preoperative anatomic localization of such lesions is obvious. In a series of four patients, resection of the lobe containing the nodule was possible and the lesions were identified after meticulous serial sectioning of the excised lung parenchyma. Two of the lesions proved to be carcinoid bronchial tumors and two others were alveolar cell carcinoma.

Adenocarcinoma, Papillary↗
PubMed1982

Infection of Aedes aegypti with zygotes of Plasmodium gallinaceum fertilized in vitro.

Female gametes of Plasmodium gallinaceum fertilized in vitro, cleaned of all other blood constituents, resuspended in blood, and fed to Aedes aegypti through a membrane were infective. At the lowest zygote concentration, 10(4)/ml, nearly every ingested parasite produced an oocyst. As the concentration ingested increased, efficiency to infect diminished, until above 10(7) zygotes/ml the number of oocysts produced became constant. This method should be valuable for determining the nutrient requirements of the ookinete and early oocyst and for studying the effect of immune sera on these stages in vivo.

Aedes↗
PubMed1982

Dialysis induced hypoxemia.

We investigated the mechanism by which hypoxemia is produced in patients on dialysis by studying changes in neutrophil count, blood gases and pulmonary function in a patient with only trace amounts of circulating C3 associated with Type II mesangiocapillary glomerulonephritis and a control group of 6 patients with normal C3 levels during a 4 hour hemodialysis. Fifteen minutes after the start of dialysis the neutrophil count fell to 13% of pre-dialysis values in the control group while it only fell to 71% in the study patient. A further fall to 47% occurred in the patient at 30 minutes. A drop in PaO2 by 15% of initial values occurred at 15 and 30 minutes in the controls and the patient respectively matching the trend of fall in the neutrophil count. PaCO2 fell sharply across the dialysis membrane with reciprocol changes in the dialysis bath. Alveolar oxygen tension showed a significant reduction starting at 15 minutes correlating with the reduction in PaO2. The A-a O2 gradient was not altered significantly. These data strongly suggest that the principal mechanism leading to hypoxemia during dialysis is hypoventilation resulting from CO2 loss into the dialysis bath. Complement mediated pulmonary leucostasis may play a secondary role in inducing a quicker fall in PaO2 in the early part of dialysis.

Adolescent↗
PubMed1981

Low-dose oral contraceptive usage and coagulation.

A prospective investigation was initiated to assess the effect of a low-dose oral contraceptive containing 35 micrograms of ethinyl estradiol and 0.4 mg of norethindrone on blood coagulation and fibrinolysis. Twenty-four women were studied before, during, and after one year of treatment. Positive results included an accelerated activated partial thromboplastin time and an increase in fibrinolytic and anticoagulation factors as measured by alpha 1-antitrypsin antigen and plasminogen antigen and activity. Antithrombin III antigen was decreased but its activity was unaffected. There was no evidence of ongoing intravascular coagulation. No patient had a detectable thromboembolic event. In short, one year's usage of this low-dose oral contraceptive was not associated with a procoagulant hematologic profile.

Antigens↗
PubMed1981

Behavioral and environmental characteristics of treated and untreated enuretic children and matched nonenuretic controls.

This correlational study investigated possible behavioral, parental, and environmental differences in enuretic children who were either receiving or not receiving treatment for bed-wetting. The subjects wer 5- to 12-year-old children who were nocturnally incontinent at least once a week and physically normal in all other respects. Seventeen of these youngsters were receiving pharmacologic treatment for enuresis (clinical enuretic group) and 20 were not (nonclinical enuretic group). Clinical enuretic children were older and wet more frequently than youngsters whose parents had not sought treatment for this problem. Their fathers more often held blue-collar jobs and their mothers were more intolerant of enuresis than were parents of the nonclinical enuretic sample. These two groups did not differ in number and type of child behavior problems, number of life-stress events, age toilet training commenced, or parental child-rearing practices employed. However, enuretic youngsters displayed more conduct problems and immature behavior than their nonenuretic counterparts. Mothers of enuretic youngsters applied more rule-oriented child-rearing practices than mothers of nonenuretic controls. There were no differences between the enuretic and nonenuretic groups in number of early-life stressful events or the age at which toilet training commenced.

Age Factors↗
PubMed1981

An electron microscopical study of the interaction of monoclonal antibodies with gametes of the malarial parasite Plasmodium gallinaceum.

Anti-malarial gamete antibodies prevent the fertilization of gametes in the mosquito midgut and prevent transmission of malaria. Recently, hybridoma cell lines secreting monoclonal antibodies (10G3 and 11C7) against gametes of the malarial parasite have been developed. These antibodies act synergistically to mediate 80--90% suppression of the infectivity of gametocytes, although neither monoclonal antibody alone has a significant effect on gametocyte infectivity. We performed immuno-electron microscopy to characterize the interactions of these monoclonal antibodies with gametes of Plasmodium gallinaceum. Male gametes exposed to either 10G3 or 11C7 agglutinated into loose clusters, while those exposed to a mixture of 10G3 and 11C7 agglutinated into long, rope-like bundles. This difference appears to be related to the distribution of the antibodies on the surface of the gametes. When 10G3 or 11C7 labeled with a ferritin-conjugated anti-mouse Ig were used singly, the ferritin particles were distributed in focal areas over the surface of the parasites. By contrast, when the male gametes were exposed to a mixture of 10G3 and 11C7, the ferritin particles were distributed over their entire surface. Female gametes reacted similarly to these antibodies. These observations indicate that combinations of antibody specificities that reduce fertilization efficiency coat the entire surface of the gametes. On the other hand, focal interactions resulting from a single antibody are unable to block fertilization.

Agglutination↗
PubMed1981

Dermatofibrosarcoma protruberans of the scalp treated by radical excision, immediate cranioplasty, and free groin flap: case report.

The authors describe a case of dermatofibrosarcoma protruberans of the frontal region in a young girl. The condition was treated by radical excision of the scalp, frontal bone, and sinuses, and immediate reconstruction with an acrylic cranioplasty and microsurgical transfer of a free groin flap. Pathological examination revealed the margins of the excised specimen were clear of tumor. The initial flap failed, but a second graft was immediately transferred successfully, with a good cosmetic result.

Adolescent↗
PubMed1980

Gametocytogenesis by malaria parasites in continuous culture.

Asexual proliferation of malaria parasites proceeds by multiplication of the parasites within red cells. Following rupture of the host cells the released merozoites re-invade other red cells. On re-invasion, a proportion of merozoites become, not asexual parasites but gametocytes, the sexual stages infective to the mosquito vectors. Conversion of asexual parasites to gametocytes occurs not only during natural infections but also in continuous in vitro culture as reported first by Trager and Jensen and by others. We showed previously that the proportion of early intra-erythrocytic stages (ring stages) of Plasmodium falciparum which developed into gametocytes in culture was influenced by culture conditions. Gametocyte formation was rare in conditions supporting rapid proliferation but frequent when parasite densisites were static. We now show that nearly 100% of ring stages develop into gametocytes in response to 1mM cyclic AMP in static cultures whereas in rapidly growing cultures few rings become gametocytes in response to cyclic AMP.

Animals↗
PubMed1980

Determinants on surface proteins of Plasmodium knowlesi merozoites common to Plasmodium falciparum schizonts.

In this report and (R. Schmidt-Ullrich, L. H. Miller, and D. F. H. Wallach. Manuscript in preparation.), we have demonstrated that malaria proteins on the surface of merozoites and infected erythrocytes cross-react between at least two primate malarias, Plasmodium knowlesi and P. falciparum. Sera from five Gambian adults who were highly immune to P. falciparum were used as a reagent to study the cross-reactivity between P. falciparum schizonts and surface proteins on P. knowlesi merozoites. Although the sera bound to the surface of viable, intact P. knowlesi merozoites, the sera did not block invasion of rhesus erythrocytes. 125I-lactoperoxidase-labeled surface proteins on merozoites formed complexes with the antibody. All major protein bands seen in the electrophoresis of the original Triton extract were bound by the immune sera. Because Gambians have never been exposed to P. knowlesi malaria, the antibodies that reacted with P. knowlesi merozoites must be directed against antigens of another parasite such as P. falciparum. We tested this hypothesis by competition for antibody in a Gambian serum between Triton-extracted antigens from P. falciparum schizont-infected erythrocytes and from surface-labeled P. knowlesi merozoites. P. falciparum inhibited the reaction, thus indicating cross-reaction between antigens in P. falciparum schizonts and P. knowlesi merozoites.

Animals↗