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Biomedical subjects

J B Cooper

Publications and source records attributed to J B Cooper.

At least 145 records · Page 8Linked to original sources
PubMed1983

Chlamydomonas agglutinin is a hydroxyproline-rich glycoprotein.

The mt(+) sexual agglutinin from Chlamydomonas reinhardi is shown to contain approximately 12% hydroxyproline, and two inhibitors of hydroxyproline formation, alpha,alpha'-dipyridyl and 3,4-dehydroproline, are shown to block the production of agglutinin activity in an in vivo bioassay system. These results indicate that the agglutinin glycoprotein may be related to a class of hydroxyproline-rich glycoproteins found in the extracellular matrix of higher plants, several of which have been shown to have lectin activity.

Journal Article↗
PubMed1983

Selective inhibition of proline hydroxylation by 3,4-dehydroproline.

The effect of proline analogs on peptidyl proline hydroxylation has been studied in vivo using aerated root slices of Daucus carota. One analog, 3,4-dehydroproline, acted at micromolar concentrations to rapidly and selectively inhibit peptidyl proline hydroxylation. A structurally altered hydroxyproline-rich cell wall glycoprotein was synthesized and secreted by dehydroproline-treated tissue. The capacity to hydroxylate proline recovered slowly following a short pulse treatment with the analog, with a halftime for recovery of about 24 hours. Recovery was not altered by supplying exogenous proline. Dehydroproline had little effect on the induction of nitrate reductase by nitrate, nor on wound-induced increases in amino acid uptake and protein synthesis. In contrast, other proline analogs inhibit proline hydroxylation only at millimolar concentrations. It is hypothesized that dehydroproline acts as an enzyme-activated suicide inhibitor of prolyl hydroxylase. This analog should become a useful tool for elucidating the functional significance of hydroxyproline-rich glycoproteins.

Journal Article↗
PubMed1982

Transient congenital hypoparathyroidism: possible association with anomalies of the pulmonary valve.

Transient congenital hypoparathyroidism was observed in four neonates who also had congenital cardiac defects. Severe hypocalcemia and hyperphosphatemia were noted at 2 or 3 weeks of age, but resolved by 2 to 4 months of age with minimal treatment (oral calcium alone). Parathyroid hormone, measured with a highly sensitive, homologous antiserum, was initially borderline detectable and became easily detectable as the hypocalcemia resolved. Immune function was normal in each patient. The congenital cardiac defects in each case involved the pulmonary valve. These patients might be regarded as having either a partial form of the DiGeorge syndrome or a separate syndrome in which congenital pulmonary valve lesions are linked to delayed maturation of parathyroid function by an as yet obscure mechanism.

Age Factors↗
PubMed1982

Critical incidents associated with intraoperative exchanges of anesthesia personnel.

It is a common practice for anesthesia to substitute for one another, especially for short breaks during long surgical procedures. The assets and liabilities of this practice of relief have not been examined previously. In the course of gathering 1,089 reports of preventable errors and failures associated with anesthesia management, we identified 96 which involved a relief anesthetist. This subset was examined in search of common characteristics and patterns of cause and discovery of errors. In 28 incidents, the relief anesthetist discovered an error or the cause of an error. In 10 incidents, the process of relief was identified as having contributed to the commission of an error. Although 70 of the 1,089 incidents were associated with substantive negative outcomes, e.g., death, cardiac arrest, or extended ICU stay, none of those incidents was caused by a relieving anesthetist. There is a strong implication that relief is beneficial more often than not even aside from the presumed beneficial effect on the vigilance of the primary anesthetist (the latter effect was outside the scope of this study). From the descriptions of the causes and discoveries of errors in these relief-related incidents, guidance can be drawn for the safe and effective conduct of the intraoperative exchange of anesthesia personnel.

Anesthesia↗
PubMed1981

Homodicentric chromosomes: a distinctive type of dicentric chromosome.

This report describes two patients with a distinctive type of dicentric autosomal chromosome formed by breakage and union between homologous chromosomes. These stable chromosomes possess two C bands, implying the presence of two centromeric regions. The first child, evaluated for dysmorphic features was shown to have an abnormal chromosome 16, designated as 46, XX, -16, + dic (16) (pter leads to cen leads to q22::p11 leads to qter). The second case is a child with the typical features of trisomy 18 whose karyotype is designated as 46, XX, -18, + dic (18) (qter leads to p11.1 :: p11.3 leads to cen leads to qter). The stability of these chromosomes is presumably in result of centromere suppression and associated premature centromere division of the suppressed centromere. The possible mechanism of formation of these homodicentric chromosomes is presented, and a comparison is made between them and three patients with dicentric X chromosomes.

Abnormalities, Multiple↗
PubMed1981

Learning from anesthesia mishaps: analysis of critical incidents in anesthesia helps reduce patient risk.

Human error and mechanical failure in anesthesia frequently cause incidents which, if not detected and corrected in time, could lead to increased patient morbidity or mortality. A study was conducted to analyze the human and technical factors that contribute to such incidents. The data thus obtained proved useful in reducing preventable anesthesia mishaps in specific institutions and generated recommendations for improving anesthesia practice in general.

Accidents↗
PubMed1980

5'-p-fluorosulfonylbenzoyladenosine as an ATP site affinity probe for Na+, K+-ATPase.

We have investigated the suitability of 5'-p-fluorosulfonylbenzoyladenosine (FSBA) as an ATP site affinity probe for the canine kidney Na+, K+-ATPase. The purified enzyme is slowly inactivated by this compound in suitable buffers, losing about half of its activity over a two-hour period. The rate of inactivation is more rapid in 0.1 M KCl than in 0.1 M NaCl. Low concentrations of ATP protect the enzyme against inactivation, with half-maximal effects at 4 microM ATP in 0.1 M NaCl and 350 microM ATP in 0.1 M KCl. ADP also protects against FSBA inhibition, but AMP is ineffective when present at 100 microM levels. This pattern is consistent with the previously described nucleotide specificity of the Na+, K+-ATPase. Addition of protective amounts of ATP after inactivation has occurred does not restore enzyme activity, indicating that inhibition is irreversible. Measurement of the concentration-dependence of FSBA inactivation suggests an apparent Kd for binding of this compound well above 1 mM, the solubility limit of the analog. This finding is reinforced by the failure of 1 mM FSBA to compete effectively with ATP for the high-affinity ATP site of the enzyme. Nevertheless, attachment of the analog to this site is indicated by its ability to prevent [3H]-ADP binding in proportion to the number of sites it has inactivated. Studies with [3H]-FSBA show that about 1 mole of the analog attaches specifically to the alpha subunit per mole of enzyme inactivated. A similar amount of nonspecific labeling also occurs with negligible effect on enzyme activity. These findings suggest that FSBA may be useful in probing the topography of the high-affinity ATP binding site of the Na+, K+-ATPase and related enzymes.

Adenosine↗
PubMed1978

A new anesthesia delivery system.

A prototype anesthesia delivery system has been developed to test the appropriateness of new technological design approaches. The objectives were to eliminate human-factors problems associated with present anesthesia apparatus and to lay a suitable technical foundation for the development of new techniques in anesthesia management. This prototype performs all the functions of a conventional anesthesia machine, as well as many monitoring and surveillance tasks. Eventual incorporation of new teaching functions, and additional monitoring and record-keeping activities, are intended. The system is fundamentally electronic with few moving parts. Reliability, safety, and clarity of operation were the primary criteria in selection and application of the specific technologies employed. The result is a promising first step in the development of a system oriented toward supporting rather than preoccupying the anesthestist.

Anesthesia↗
PubMed1978

Preventable anesthesia mishaps: a study of human factors.

A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty-seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty-three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82 per cent), with breathing-circuit disconnections, inadvertent changes in gas flow, and drug-syringe errors being frequent problems. Overt equipment failures constituted only 14 per cent of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia.

Accident Prevention↗
PubMed1976

The effect of protein and dietary energy levels and housing regime on production and reproduction parameters of turkey hens.

Two experiments were conducted using 960 Large Board Breasted White turkey hens to measure the effect of diet and confinement housing versus range pens on egg production, fertility and hatchability. A 2 X 3 factorial arrangement of diets provided protein levels of 15 and 18% with metabolizable energy levels of 2666, 2893, and 3101 kcal. per kg. of diet. The hens were randomized into 24 range pens and 24 pens in an open-sided house. Dietary protein levels had no effect on body weight, feed consumption, egg production, fertility or hatchability. Hens fed the higher energy diet produced larger eggs (P less than .05), but there was no difference in total egg production due to dietary energy level. As dietary energy level increased, feed consumption linearly decreased. Hens fed the 3102 kcal./M.E./kg. diet had significantly higher fertility (P less than .05) than hens fed the intermediate energy level diet with no differences between the lowest energy level and either of the other two levels. Fertile eggs from hens fed the intermediate energy level diet had lower hatchability (P less than .05) than those from hens fed either the lower or higher dietary energy levels. Type of housing and no effect on average body weight or feed consumption on a hen-day basis. Housing treatment had no effect on percent fertility or hatchability. Hens housed in the range pens produced more and larger eggs (P less than .05) and more eggs per kg. of feed than hens penned in the house.

Animals↗
PubMed1976

Light intensity and housing for pigeons.

Four light intensities were used in completely enclosed pigeon housed for 14 hours per 24 hours. Open front pens with only natural light were also used. There were four pens per treatment and five pairs of young, breeding age, White Carneaux per pen for 420 days. Results per treatment, 16, 30, 44 and 61 lumens per sq. m. and open pens, were respectively as follows for each objective: squabs raised-252, 220, 288, 203, and 212 with no significant differences except for the 44 lumen treatment which was higher than all others except 16; body wt./squab in g.-522, 526, 522, 508, and 531 at four weeks of age with no significant differences; feed per squab in kg.-4.7, 5.3, 4.5, 5.5, and 5.1 with only a significant difference between treatments 44 and 61 lumens; percent hatchability-89.7, 82.1, 89.6, 78.0, and 82.9 with no significant differences; percent squabs raised-93.7, 88.7, 97.9, 91.0, and 89.5 with no significant differences. The average number of squabs raised per treatment for all enclosed artifically lighted pens was 241 compared to 212 for the open pens with only natural light.

Animals↗
PubMed1976

Twin pigeon embryos.

Twin pigeon embryos were found on incubation day 18 in a pipped egg. The egg was pipped at the small end. The embryos were dead. Removal of a portion of the shell allowed removal of one embryo and revealed the second one. Both appeared normal in development and size.

Animals↗