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Biomedical subjects

J Carver

Publications and source records attributed to J Carver.

35 records · Page 2Linked to original sources
PubMed1982

Further studies on the quantitation of the hemoglobins A, S, C, and F in newborn babies with different hemoglobinopathies using high pressure liquid chromatography.

High pressure liquid chromatography (HPLC) has been used for the detection and quantitation of the beta chain variants Hb S and Hb C in blood samples of newborn babies with different hemoglobinopathies. The complete separation of the Hbs C, S, A, and F made it possible to diagnose conditions such as AS AC, SS, CC, SC and even S(C)-beta+ thalassemia. The procedure is fast (62 min) and ideally suited for the quantitation of Hb F at birth. Data for a few hundred cord blood samples indicate a great variability in the relative quantities of Hb S or Hb C in heterozygotes which prevents a definitive diagnosis of a simultaneously occurring alpha-thalassemia except perhaps of the homozygous form of alpha-thalassemia-2 (alpha o alpha/alpha o alpha). The large spread in the data also shows some overlap between the quantitative results in Hb S (or Hb C) heterozygotes and in babies with the Hb S (Hb C)-beta-thalassemia condition.

Chromatography, High Pressure Liquid↗
PubMed1981

Application of high-field proton magnetic resonance spectroscopy in the structural determination of membrane-derived Sindbis virus glycopeptides.

Sindbis virus membrane glycopeptides have ben purified in chemical quantities and their oligosaccharide structures analyzed by 1H NMR spectroscopy at 360 MHz. Interpretable spectra could be obtained with approximately 100 micrograms of oligosaccharide. Spectral analysis of the sialyl glycopeptides S1, S2, and S3 at high and low temperatures confirms their structures to be NANA alpha (2,3)Gal beta (1,4)-GlcNAc beta (1,2)Man alpha (1,6)-[NANA alpha (2,3)Gal beta (1,4)-GlcNAc beta (1,2)Man alpha (1,3)]-Man beta (1,4)GlcNAc beta (1,4)-[Fuc alpha-(1,6)]-GlcNAc beta 1-Asn. These are heterogeneous with respect to sialic acid (NANA). Spectra of two endo-beta-N-acetylglucosaminidase products of the S4 glycopeptides are reported. The interpretation of these spectra is consistent with Man5GlcNAc and Man7GlcNAc oligosaccharide structures. Their chemical shifts are essentially identical with those reported for ovalbumin glycopeptides of the same composition, with exception to the perturbations arising from their oligosaccharide nature.

Animals↗
PubMed1979

Microchromatographic quantitation of fetal hemoglobin in patients with sickle cell disease.

A microchromatographic procedure (Isolab Fast Hb Test System) which was developed for the quantitation of Hb AI (10) has been found useful for the quantitation of Hb F in samples that contain Hb S and/or Hb C but no Hb A (% Fmicro). This method has been evaluated through analyses of known mixtures of Hb F and Hb S. The Hb Fmicro levels in patients with sickle cell anemia and related conditions were compared with results obtained by alkali denaturation (% FAD) and conventional DEAE-cellulose chromatography (% FDE). This microchromatographic technique is a fast, simple, and sensitive method for Hb F quantitation in patients with Sickle cell disease.

Adult↗
PubMed1977

Unsuspected left-to-right shunt: is routine use of hydrogen platinum electrode system indicated in shunt detection?

Unsuspected left-to-right shunt was found in 6 of 1,500 adult patients undergoing diagnostic cardiac catheterization. In 3 patients were found unsuspected secundum atrial septal defects (1 associated with mitral stenosis and 2 with coronary artery disease). In 3 patients, unsuspected partial anomalous pulmonary venous drainage was found (1 associated with aortic valve disease and 2 with severe coronary artery disease). It is concluded that the incidence of unsuspected left-to-right shunt diagnosed during routine cardiac catheterization is very low. Careful physical examination and the application of conventional techniques during cardiac catheterization should suggest the possibility of such a shunt. Hydrogen platinum electrode system (HPES) should be reserved for patients in whom the right heart catheter takes an abnormal course or when the pulmonary artery oxygen saturation is high and the arteriovenous oxygen difference is small.

Adult↗
PubMed1975

Ultrathin coating by plasma polymerization applied to corneal contact lens.

Plasma coating (deposition of polymer under the influence of plasma) is utilized to modify the surface properties of corneal contact lens. An ultrathin layer (thickness of roughly 200 A) of plasma polymer of acetylene/H20/N2 is applied to poly(methyl methacrylate) (PMMA) corneal contact lenses. The surface becomes highly wettable with water compared to uncoated lens. When coated and uncoated contact lenses are placed on rabbit eyes, a remarkable difference in accumulation of mucous matter is observed. With the control lenses, the accumulation of mucous matter in a week is sufficient to affect the optical clarity of the lenses, whereas the coated lenses show no change after three months continuous wearing. The comparative degree of adhesion of the corneal epithelium cells onto glass, modified glass, PMMA, and coated PMMA surfaces is studied using tissue cultures and phase contrast microscopy. The coated PMMA surface exhibits a degree of tissue adhesion lower than that of control PMMA and higher than that of glass surface, and no sign of toxicity of the coated surface is observed by the tissue cultures.

Acetylene↗
PubMedDate not supplied

Blockade of drug-induced deficits in prepulse inhibition of acoustic startle by ziprasidone.

Ziprasidone, an antipsychotic with efficacy against core symptoms of schizophrenia and schizoaffective disorder, has a low incidence of extrapyramidal syndrome (EPS). Because of its high 5-HT(2A)/D(2) binding-affinity ratio and low EPS liability, ziprasidone is considered to belong to the newer class of "novel" antipsychotics typified by clozapine. Its unique pharmacological profile, however, distinguishes it from other novel agents. We evaluated ziprasidone in the prepulse inhibition (PPI) model, which is sensitive to clinically active antipsychotics. Male Wistar rats were tested in acoustic startle sessions in which some startle-eliciting stimuli were presented alone, and others were preceded by a weak prepulse. Administration of the dopamine agonist apomorphine (1 mg/kg) or the N-methyl-D-aspartate (NMDA) antagonist ketamine (10 mg/kg) significantly disrupted PPI. When coadministered with either of these compounds, clozapine (1-5.6 mg/kg sc) and ziprasidone (5.6-17.8 mg/kg po) significantly attenuated the declines in PPI. Haloperidol (0.03-0.56 mg/kg) also attenuated drug-induced deficits in PPI but to a lesser extent (and at higher doses) with ketamine than with apomorphine. Together, these data confirm that ziprasidone shares common effects in PPI models with other novel antipsychotics. Ziprasidone's affinity for non-D(2) receptors in the central nervous system may partly account for its attenuation of ketamine's effect.

Acoustic Stimulation↗
PubMedDate not supplied

A model for strategic leadership.

Boards can exercise strategic leadership, but to do so well, they must change their concept of governance. Most of what is traditionally accepted in the boardroom is not conducive to excellence in strategic leadership and, in fact, actually impedes it. First, trustees must be able to escape the clutter that interferes with a continual emphasis on strategic issues. This calls for a far more incisive way to withdraw responsibility from administrative tissues in favor of control by policy. Second, trustees must understand that strategic leadership is a matter of how the board approaches its job, not a mechanical annual tussle with setting long-range goals. Third, trustees must structure their annual plans around updating their long-range intentions--chiefly concerning mission issues and priorities--and restating them in amended ends policies. Finally, trustees must realize that strategic leadership--hence, good governance--is not so much about budgets, personnel practices, construction projects or medical staff bylaws as it is about public policy, purpose, values and the vision that shapes institutional destiny.

Canada↗