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Biomedical subjects

C D Smith

Publications and source records attributed to C D Smith.

At least 271 records · Page 15Linked to original sources
PubMed1983

Phosphorylation of rat liver nuclear envelopes. I. Characterization of in vitro protein phosphorylation.

Nuclear envelopes were prepared from purified rat liver nuclei by lysis with heparin, digestion with deoxyribonuclease I (DNase I), or sonication. The envelopes were fractionated by centrifugation on sucrose density gradients and analyzed for protein kinase activity using endogenous and exogenous protein substrates and [gamma-32 P]ATP. The protein kinase activity toward endogenous proteins was markedly affected by the method used to isolate the envelopes, with sonication producing a preparation with very low activity. At least 12 phosphoproteins in nuclear envelopes isolated by the heparin or DNase I method were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. A 32P-labeled material migrating with an apparent Mr = 3000 was extracted with chloroform:methanol:HCl and was identified as a mixture of phospholipids. Total 32P incorporation into nuclear envelopes peaked at 5 min of incubation, followed by a decrease in labeled products. This decrease was due to both phosphoprotein phosphatase activity and degradation of the lipid products. The highest protein kinase activity toward endogenous proteins was expressed with [gamma-32P]ATP in the presence of MgCl2; however, some phosphorylation also occurred with MnCl2, CoCl2, NiCl2, and [gamma-32P]GTP in the presence of MgCl2. Nuclear envelope protein phosphorylation was unaffected by cyclic nucleotides and calmodulin, slightly inhibited by CaCl2, MnCl2, CoCl2, disulfides, and sulfhydryl alkylating agents, and strongly inhibited by LaCl3 and phosphatidylglycerol. Nuclear porelamina complexes isolated from phosphorylated envelopes contained phosphoproteins of 7, 20, 51, 59, and 70 kDa. Incubation of pore-lamina complexes isolated from unlabeled envelopes with [gamma-32P]ATP resulted in 32P incorporation into the 20-, 51-, and 50-kDa proteins.

Adenosine Triphosphatases↗
PubMed1983

Phosphorylation of rat liver nuclear envelopes. II. Characterization of in vitro lipid phosphorylation.

Incubation of nuclear envelopes isolated from normal rat liver with [gamma-32P]ATP resulted in the rapid labeling of chloroform-soluble products. These products were identified as phosphatidic acid (PA), phosphatidylinositol 4-phosphate (DPI), and phosphatidylinositol 4,5-bisphosphate (TPI) based on their chromatographic mobilities on Silica Gel H and cellulose thin layer plates, and by analysis of their deacylation products by high pressure liquid chromatography. The extent of phosphorylation of these products was dependent on the method used to isolate the nuclear envelopes. Relatively gentle isolation methods, such as lysis of purified nuclei with heparin or digestion with deoxyribonuclease I, produce nuclear envelopes which possess significantly higher lipid kinase activity than do envelopes isolated by sonication. Incorporation of 32P into PA, DPI, and TPI in 2 min under standard assay conditions was 13, 152, and 22 pmol/mg of membrane protein, respectively. Degradation of labeled DPI and TPI was evident after 2-5 min of incubation. Nuclear envelope-associated diacylglycerol kinase, phosphatidylinositol kinase, and DPI kinase are characterized with regard to their pH and Mg2+ requirements. The effects of metals, phospholipids, and sulfhydryl reagents on these kinase activities are also described.

1-Phosphatidylinositol 4-Kinase↗
PubMed1983

A clinical comparison of dentinal slot retention with metallic pin retention.

Twenty-two pairs of extensive amalgam restorations were placed in 19 patients. One amalgam of each pair had self-threading pin retention, and the other had dentinal slot retention. Evaluations were done at baseline, at one, and two years. After two years, 17 pairs of amalgams were available for evaluations. The data obtained can be summarized as follows: 100% (17) of the slot-retained amalgams were clinically acceptable, whereas 94.1% (16) of the pin-retained amalgams were acceptable. It can be concluded that, in clinical usage, dentinal slot retention is as effective as self-threading pin retention in extensive amalgam restorations.

Adult↗
PubMed1982

Controlled trial of nifedipine in the treatment of Raynaud's phenomenon.

17 patients with moderate to severe Raynaud's phenomenon were entered into a 6 week randomised double-blind crossover study to compare the efficacy of nifedipine with that of placebo. Nifedipine significantly reduced the frequency of attacks and also the severity of attacks, which was assessed by the patients on a linear analogue scale. Patients gave nifedipine a significantly higher drug-effectiveness score than placebo. Skin temperature recovery times were not affected by treatment with nifedipine. 12 of the patients regarded nifedipine as effective in reducing the frequency and severity of Raynaud's phenomenon.

Adolescent↗
PubMed1982

An automated PSRO-utilization review system.

A set of computer programs collects, processes, and reports Professional Standards Review Organization (PSRO) and utilization data for all patients at the Miami Heart Institute. They help reduce the time spent by physicians in PSRO and utilization review activities and ease the clerical work load required to comply with rules and guidelines. Daily printed reports provide attending physicians with their patient census and inform them of the next scheduled PSRO review dates for each of their patients. Reports are produced also for the Utilization Review Committee and the Institute's PSRO office. This set of programs is part of a comprehensive automated hospital information system and has been designed to respond rapidly to the frequent changes in regulations and policies dictated by the administering agency. The PSRO subsystem had been in uninterrupted operation for over 6 years and has mitigated escalating clerical and, therefore, health care costs. Physicians' acceptance of this subsystem had been adequate; however, developmental and maintenance costs are high in comparison with other applications within the hospital information system. This article describes the methodology used in complying with PSRO requirements. It does not attempt to evaluate the impact of PSRO on quality of care or length of hospital stay.

Cardiac Care Facilities↗
PubMed1982

The diagnostic laboratory tests for histoplasmosis: analysis of experience in a large urban outbreak.

Of 495 patients reported in a large urban histoplasmosis outbreak, we studied 276 whose serologic tests were done in a single laboratory. Serologic test results were positive in 96% of these patients (compared with less than 5% of controls from an endemic area), cultures were positive in 22%, and special stains in 19%. The immunodiffusion test results were negative in 13% of patients who had positive findings by complement fixation, and 1% had positive results only by immunodiffusion. The complement fixation test was almost twice as sensitive as the immunodiffusion test in patients with subclinical infection. The serologic response differed significantly among the clinical syndromes with higher titers in cavitary and lower titers in disseminated disease. Factors associated with titers of 1:64 or greater to both antigens were black race and immunocompetence. High mycelial titers were also associated with more intense exposure, and high yeast titers were associated with age less than 36 years. No prognostic significance could be proved for fourfold titer rises or falls or persistence of precipitins.

Adolescent↗
PubMed1979

Fabrication of removable stone dies using cemented dowel pins.

Proper dowel pin placement in the working cast is important in the fabrication of a cast restoration. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship.

Cyanoacrylates↗
PubMed1979

The role of the physician's assistant in a university-based pediatric surgical service.

Physician's Assistants (P.A.), recent additions to the health profession, have proved valuable as "extenders" for primary physicians in relatively remote rural areas. More specialized surgical assistants have been trained for the community-practicing surgeon. The introduction of physician's assistants into university centers has been proceeding at a slower pace. A need has existed for an accurate assessment of the role of the P.A. in a residency-training program. In subspecialties, such as pediatric surgery and thoracic surgery, an increasing patient load has usually required a corresponding increase in junior resident staff. This resident coverage is usually dependent upon the availability of general surgical house staff since pediatric surgical trainees are currently fixed in number. Foreign medical graduates are no longer available in large numbers and general surgical programs themselves are being reevaluated and the number of trainees decreased. In this setting physician's assistants can be used to augment patient coverage by acting as junior surgical residents.

Academic Medical Centers↗
PubMed1978

Hemolytic-uremic syndrome: a diagnostic and therapeutic dilemma for the surgeon.

The hemolytic-uremic syndrome consists of microangiopathic hemolytic anemia, acute renal failure, and thrombocytopenia following a prodromal illness of gastroenteritis or upper respiratory infection. The syndrome can present in dramatic fashion with severe abdominal pain and signs of peritonitis suggesting an acute surgical crisis. In a series of 25 patients, 40% had abdominal pain, 25% had abdominal tenderness, and 20% had peritoneal signs. Clues to diagnosis in the early stages of the acute illness were mild to moderate hypertension, abnormal peripheral blood smear, anemia despite dehydration, and proteinuria. Significant abdominal pain and x-ray evidence of colitis may occur before development of typical laboratory findings, and these were evident in at least one case. Three patients underwent laparotomy for suspected bowel perforation. Colitis without perforation was found in all cases. In the absence of documented perforation, toxic megacolon, or intussusception, the decision to perform laparotomy in patients with hemolytic-uremic syndrome who have signs of peritonitis must be individualized. Failure to recognize the underlying renal problem can lead to serious errors in fluid and electrolyte management and delay of appropriate therapy.

Child↗
PubMed1978

Immunogenicity of serogroup A and C Neisseria meningitidis polysaccharide vaccines administered together in humans.

Serogroup A and C Neisseria meningitidis polysaccharide vaccines were administered to U.S. Army recruit volunteers, either two weeks apart or at the same time into two different sites on the same arm, to determine what effect, if any, the combined administration would have on the immunogenicity of each individual component. The vaccines were found to be as immunogenic when administered together as when given separately; in fact, the data suggest a possible enhancement of the response, as measured by the radioactive antigen binding test, to both components when the two vaccines are given together.

Antibody Formation↗
PubMed1976

Effect of immunosuppressants on dogs exposed two and one-half years previously to Blastomyces dermatitidis.

Observation of 33 dogs exposed to Blastomyces dermatitidis over a 2 1/2 year period is reported. During the first 1 1/2 years six dogs died and 23 (77%) developed skin lesions. Clinical evidence of disease in all the animals then subsided and remained so through another year of observation. Nine animals were sacrificed after 120 weeks and several tissues were cultured from each one. The remaining 18 were given immunosuppressants--azathioprine, prednisone, and cyclophosphamide--for eight weeks prior to autopsy. About one-half of the dogs were found to be infected with Histoplasma capsulatum and all were negative for B. dermatitidis by culture. The dogs were thought to have been inadvertently exposed to H. capsulatum during the first eight weeks of observation from a nearby soil plot before being moved to a more remote shelter. Skin testing with histoplasmin and blastomycin and complement-fixation (CF) tests, performed at various intervals after exposure to B. dermatitidis, appeared to reflect the course of disease with the number of reactors to the H. capsulatum antigens remaining relatively high while the number of reactors to B. dermatitidis antigens fell with the passage of time. The blastomycin skin test results in these dogs, however, persisted far longer than positive Blastomyces CF results. These data suggest that most dogs exposed to B. dermatitidis exhibit clinical symptoms of disease after about 12 weeks, persisting for about one year. The majority of animals recover spontaneously and completely. With H. capsulatum, however, the infection can be subclinical for at least a two-year period.

Animals↗