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Biomedical subjects

J Holbrook

Publications and source records attributed to J Holbrook.

14 recordsLinked to original sources
PubMed1992

Cystic degeneration of a leiomyoma masquerading as a postoperative abscess.

Leiomyomas are common tumors that usually have a typical sonographic appearance. With degeneration, however, the sonographic findings may be completely uncharacteristic. We report a case of a multicystic anterior uterine wall mass detected at antenatal sonography in an asymptomatic patient. Differential diagnosis included myoma, varicosity, hematoma, abscess, uterine anomaly, and pelvic neoplasm. At cesarean section, the mass was confirmed to be a myoma. Postoperatively, an ultrasound was performed by the radiology service during evaluation of suspected endometritis and the mass was interpreted as an endometrial abscess. This case illustrates that myomas can present with sonographic features consistent with a number of pathologic disorders. This variable pattern of echogenicity may sometimes create difficulty in establishing a correct diagnosis. The case also demonstrates the importance of communication between services and the need for not only antenatal but also postpartum and gynecologic ultrasound studies to be performed by physicians trained in sonographic findings of the abnormal uterus.

Abscess↗
PubMed1991

The Massachusetts Emergency Medicine Risk Management Program. Massachusetts Chapter of the American College of Emergency Physicians.

Reducing malpractice claims incidence and improving the quality of patient care are the goals of the Massachusetts Emergency Physician Risk Management Program. This innovative program entails computer audit of records in high-risk diagnostic categories. The program focuses on increasing physician awareness of high-risk diagnoses and on medical record documentation of a few critical actions pertinent to each diagnostic area.

Algorithms↗
PubMed1990

Preventability of malpractice claims in emergency medicine: a closed claims study.

We conducted a retrospective study of 262 malpractice claims against emergency physicians insured in Massachusetts by the state-mandated insurance carrier; these 262 claims were closed in the years 1980 through 1987. A total of $11,800,156 in indemnity and expenses was spent for these 262 claims. In 211 cases, the allegation was failure to diagnose a medical or surgical problem. One hundred eighty-four of these cases were included in the following eight diagnostic categories: chest pain, abdominal pain, wounds, fractures, pediatric fever/meningitis, aortic aneurysm, central nervous system bleeding, and epiglottitis. These eight categories accounted for 66.44% of the total dollars spent for the 262 claims. Because of the high incidence and dollar losses attached to these eight diagnostic categories, the Massachusetts Chapter of the American College of Emergency Physicians (MACEP) has developed clinical guidelines for the evaluation of these high-risk areas. Of the 184 high-risk claims, 99 claim files were reviewed; 45 of these reviewed claims were judged by physician reviewers as preventable by the application of the MACEP high risk clinical guidelines. From 22.26% to 46.4% of the $11,800,156 spent on the 262 claims could have been saved by the application of the MACEP clinical guidelines.

Chest Pain↗
PubMed1990

A computerized audit of 15,009 emergency department records.

The text of 15,009 emergency department medical records was reviewed with the use of a computer program that detected the presence or absence of key words and phrases. The search focused on "trigger diagnoses," that is, any diagnoses associated with an above-average risk for an undetected but more serious condition. Included were the trigger diagnoses from the five high-risk areas of extremity laceration, epiglottitis, abdominal pain, meningitis, and myocardial infarction. The three kinds of medical records that were compared were handwritten records, records dictated and transcribed, and records created by a voice-activated word processor. From a risk management perspective, inclusion of critical pertinent positives and negatives was taken as an index of quality from a risk management perspective, and records created by a voice-activated word processor using real-time risk management prompts were superior to handwritten and dictated records. The computer holds promise as a vehicle to reduce the cost and frequency of malpractice risk in the ED and as a teaching tool to improve the quality of care.

Computers↗
PubMed1987

Effect of heparin and citrate on measured concentrations of various analytes in plasma.

Frequently it is assumed that concentrations of biochemical analytes are similar for serum and plasma, without regard to the anticoagulant. Recently it has been hypothesized that use of certain anticoagulants results in an osmotic redistribution of fluid between blood cells and plasma, causing some dilution of the plasma. We sought to determine the effect of two commonly used anticoagulants, heparin and citrate, on the measured concentrations of 13 clinical-chemical analytes, including selected trace elements, vitamins, lipids, and proteins. The data demonstrate that hyperosmolar citrate causes a significant dilution of all indices measured. In contrast, heparin had no osmotic effect; concentrations of most of the analytes measured in the heparinized plasma were statistically no different from those measured in the corresponding serum. Therefore, anticoagulants must be chosen carefully, especially if concentrations in plasma and serum are to be compared.

Blood Chemical Analysis↗
PubMed1986

Stability of teacher temperament ratings over 6 and 12 months.

Six and 12-month stability of teacher ratings of temperament was studied in four samples. For the two samples retested after a 6-month interval, the same teacher provided the original and retest ratings. For the two samples retested after a 12-month interval, different teachers provided the retest ratings than provided the original ratings. Four indices of stability were investigated for each sample: cross-rank stability, within-person stability , absolute score stability, and factorial stability. Factorial stability was demonstrated for all samples. For the other three indices of stability, 6-month stability was moderate to high, and significantly higher than the 12-month stability. The general pattern of results is comparable to temperament rating data from parents, with specific coefficients being somewhat higher.

Child↗
PubMed1986

Contrasting effects of the stomach and small intestine of rats on copper absorption.

Since the severity of copper deficiency has been shown to be enhanced by feeding diets containing fructose but ameliorated by diets containing starch, we decided to investigate the effect of fructose or starch on copper absorption. As copper transport has been reported to occur also from the stomach, it was possible that copper absorption is inhibited by fructose already from that tissue. Under anesthesia, stomachs of 72 rats fed copper-deficient or supplemented diets containing fructose or starch were ligated prior to the oral administration of 64Cu. Gastric absorption of 64Cu was studied when the isotope was administered by gastric tube either in diet containing fructose or starch or in water. 64Cu was not absorbed from the stomach regardless of the type of dietary treatment, copper status or whether the copper was administered either in diet or in water. In addition, the absorption of 64Cu from a diet containing either fructose or starch or from a saline solution was studied using the isolated ligated duodenal loop. When 64Cu was administered with dietary fructose 64Cu retention and absorption were impaired when compared to starch. When 64Cu was administered in saline solution, differences in retention and absorption between the four dietary groups disappeared. It is suggested that the requirements for copper rather than the decreased absorption of copper are responsible at least in part for the more pronounced severity of copper deficiency in rats fed fructose compared to those fed starch.

Absorption↗
PubMed1986

Effect of fructose or starch on copper-67 absorption and excretion by the rat.

Studies with 67Cu were conducted with copper-deficient or supplemented rats fed fructose or starch in an effort to investigate the effects of different dietary carbohydrates and inadequate copper intake on the absorption, tissue distribution and excretion of copper. After being fed their diets for 5 wk, they were killed at 8, 24, 48 and 96 h following the intubation of their respective copper-supplemented diets extrinsically labeled with 67Cu. Only at 48 and 96 h following the intubation of 67Cu, the gastrointestinal (GI) contents of rats fed the copper-deficient fructose diet exhibited higher radioactivity than rats fed the copper-deficient starch diet. Although not always significant, this apparent retention of copper in GI contents was accompanied by decreased whole-body radioactivity and depressed urinary excretion. The cumulative excretion of 67Cu via feces over the 96-h period of collection was similar for both groups of copper-deficient rats, regardless of whether the dietary carbohydrate was fructose or starch. The data suggest that the more severe copper deficiency is related to the sustained higher level of radioactivity in the GI contents. This increased retention of 67Cu in GI contents suggests impaired absorption of copper.

Animals↗
PubMed1986

Tissue distribution and excretion of copper-67 intraperitoneally administered to rats fed fructose or starch.

It has been suggested that impaired gut absorption of copper is the cause of the exacerbated copper deficiency signs in rats fed fructose when compared to rats fed starch. The present study was designed to examine how rats fed fructose or starch diets, either copper-deficient or supplemented, distributed and excreted 67Cu when the isotope was administered i.p. Intraperitoneal administration was chosen in an effort to circumvent primary gut absorption as a factor in the metabolism of 67Cu. After 7 wk of dietary treatment, rats received an i.p. injection of 67Cu and were placed in metabolic cages for 4 d. Regardless of dietary carbohydrate, copper-deficient rats retained similar levels of radioactivity in various tissues and excreted similar amounts of 67Cu in feces and urine. This similarity in copper metabolism in copper-deficient rats fed either fructose or starch when the gut was circumvented for isotope administration suggests that the gut could be responsible, at least in part, for the exacerbated signs associated with the copper deficiency in rats fed fructose. The possibility is discussed that alterations in metabolism may increase the requirement for copper when fructose is the main dietary carbohydrate.

Administration, Oral↗
PubMed1986

Development of copper deficiency in rats fed fructose or starch: weekly measurements of copper indices in blood.

Copper deficiency was induced in weanling rats fed diets whose sole source of carbohydrates was starch or fructose for 7 weeks. Conventional parameters of copper status, plasma copper concentrations, ceruloplasmin activity, and erythrocyte superoxide dismutase (SOD) activity were longitudinally monitored weekly to follow the development of the deficiency and to correlate these indices with the degree of severity of the deficiency. Although 30% of the rats fed a copper-deficient fructose diet died and no deaths occurred in rats fed the copper-deficient starch diet, plasma copper, ceruloplasmin, and SOD activities were reduced to a similar extent in all rats fed copper-deficient diets regardless of the type of dietary carbohydrate. Thus, none of the indices used accurately reflected the greater degree of deficiency or mortality in rats fed the fructose diet deficient in copper. The results of the present study underscore the need for more sensitive tests or alternative parameters to assess copper status in living animals.

Animals↗
PubMed1979

Prison health and medical education.

Prison health has long been neglected as an area of serivice by organized medicine and a site for clinical education by health science centers. The University of New Mexico Health Science Center offers an elective, weekly clinical experience for preclinical medical students, senior nursing students, and senior pharmacy students at a prison facility in need of medical services. Students' reaction to the prison experience was strongly positive. Most developed empathy toward the inmates and a greater understanding of prison health problems. Inmates rated the student service highly and requested its continuation. This community health education experience has provided a noncontractual model of a university-prison health alliance.

Ambulatory Care Facilities↗
PubMed1978

Malate dehydrogenase of the cytosol. A kinetic investigation of the reaction mechanism and a comparison with lactate dehydrogenase.

1. The mechanisms of the reduction of oxaloacetate and of 3-fluoro-oxaloacetate by NADH catalysed by cytoplasmic pig heart malate dehydrogenase (MDH) were investigated. 2. One mol of dimeric enzyme produces 1.7+/-0.4 mol of enzyme-bound NADH when mixed with saturating NAD+ and L-malate at a rate much higher than the subsequent turnover at pH 7.5. 3. Transient measurements of protein and nucleotide fluorescence show that the steady-state complex in the forward direction is MDH-NADH and in the reverse direction MDH-NADH-oxaloacetate. 4. The rate of dissociation of MDH-NADH was measured and is the same as Vmax. in the forward direction at pH 7.5. Both NADH-binding sites are kinetically equivalent. The rate of dissociation varies with pH, as does the equilibrium binding constant for NADH. 5. 3-Fluoro-oxaloacetate is composed of three forms (F1, F2 and S) of which F1 and F2 are immediately substrates for the enzyme. The third form, S, is not a substrate, but when the F forms are used up form S slowly and non-enzymically equilibrates to yield the active substrate forms. S is 2,2-dihydroxy-3-fluorosuccinate. 6. The steady-state compound during the reduction of form F1 is an enzyme form that does not contain NADH, probably MDH-NAD+-fluoromalate. The steady-state compound for form F2 is an enzyme form containing NADH, probably MDH-NADH-fluoro-oxaloacetate. 7. The rate-limiting reaction in the reduction of form F2 shows a deuterium isotope rate ratio of 4 when NADH is replaced by its deuterium analogue, and the rate-limiting reaction is concluded to be hydride transfer. 8. A novel titration was used to show that dimeric cytoplasmic malate dehydrogenase contains two sites that can rapidly reduce the F1 form of 3-fluoro-oxaloacetate. The enzyme shows 'all-of-the-sites' behaviour. 9. Partial mechanisms are proposed to explain the enzyme-catalysed transformations of the natural and the fluoro substrates. These mechanisms are similar to the mechanism of pig heart lactate dehydrogenase and this, and the structural results of others, can be explained if the two enzymes are a product of divergent evolution.

Chemical Phenomena↗
PubMed1976

The binding by an NAD-affinity matrix of contaminating dehydrogenases in cytochrome c oxidase preparations.

An NAD-matrix is capable of the separation of three contaminant reductase activities from highly purified beef heart cytochrome c oxidase. Non-specific binding of cytochrome c oxidase occurs as well. When the matrix is saturated with respect to the non-specific binding, continued binding of the reductases can be observed. As a consequence of equilibration with the matrix, the turnover numbers of the unbound cytochrome c oxidase are increased.

Chromatography, Affinity↗