Showing papers by "University of Colorado Denver published in 1977"

Nonoliguric acute renal failure.

Abstract: To delineate the clinical spectrum of nonliguric renal failure, we studied prospectively 90 patients with acute renal failure 54 of whom were nonoliguric throughout their periods of azotemia. Although the causes of nonoliguric renal failure varied, nephrotoxic failure occurred more frequently in nonoliguric than in oliguric subjects (P is less than 0.01). As com pared to oliguric patients, those without oliguria had significantly lower urinary sodium concentrations (P is less than 0.05) and fractional excretions of sodium (P is less than 0.02), had shorter hospital stay (P is less than 0.01), had fewer septic episodes, neurologic abnormalities, gastrointestinal bleeding and acidemia, required dialysis less frequently (P is less than 0.001) and had lower mortality rate (26 per cent in nonoliguric vs. 50 per cent in oliguric patients -- P is less than 0.05). Nonoliguric renal failure occurs more often than is generally recognized and causes less morbidity and mortality than oliguric acute renal failure.

Membranes and Energy Transduction in Bacteria

Abstract: Publisher Summary This chapter discusses the mechanisms by which bacterial membranes generate useful energy and perform the work of chemical synthesis, transport, and movement. Bacteria do generate a proton-motive force by the vectorial and electrogenic translocation of protons. This force can support the physiological functions normally energized by metabolism. Membrane vesicles conserve energy for phosphorylation and for performing physiologically useful work. Bacteria employ two different classes of reactions to make energy available. One class consists of macroscopically scalar reactions that generate ATP and other energy-rich compounds by substrate-level phosphorylation. The second class consists of pathways that translocate protons vectorially across a membrane to generate a proton circulation. All bacteria possess the proton-translocating ATPase that links cytoplasmic ATP to the proton circulation. The synthesis of ATP during oxidative and photosynthetic phosphorylation is apparently accompanied by substantial changes in the configuration of the ATPase

“Think Aloud”: A program for developing self-control in young aggressive boys

Abstract: "Think Aloud" was designed as a training program to improve self-control in 6- to 8-year-old boys. It involved modeling and verbalization of cognitive activity to foster use of verbal mediation skills in dealing with both cognitive and interpersonal problems. It was hypothesized that this training would lead to improvement in test performance and teacher ratings of classroom behavior in hyperaggressive boys. Twelve aggressive second grade boys participated in daily, 30-minute, individual sessions for 6 weeks. Normal and aggressive control subjects received no intervention. Teachers rated both trained and untrained aggressive boys as improving in aggressive behaviors but they rated the experimental group as showing improvement on a significantly larger number of prosocial behaviors. The pattern of performance on cognitive tests also changed significantly in the experimental group. On pretest, their pattern differed from normals and resembled the aggressive control group, while on posttest their pattern resembled normals and differed from agressive controls. Suggestions were made concerning additional refinements needed in the program, but overall results indicated potential value in the present approach for providing assistance to aggressive boys in the early grades.

Distribution of cardiac output in ovine pregnancy

Abstract: Cardiac output and organ blood flows were measured in 6 nonpregnant and 24 pregnant ewes from 38 to 141 days of gestation employing radionuclide-labeled microspheres. From the nonpregnant state to term increases in cardiac output, from 73.7 +/- 4.6 ml/min-kg of maternal weight to 148 +/- 2.4 ml/min-kg, and heart rate, from 88.5 +/- 10.3 to 106 +/- 4.6 beats/min, were noted, while mean arterial blood pressure was unchanged. Near term, the blood flows to the uterus and mammary gland represented approximately 18% of cardiac output. The blood flow to nonreproductive organs increased from 76.6 +/- 6.8 ml/min-kg of nonreproductive tissue in the nonpregnant state to 132 +/- 3.5 ml/min-kg at 130-140 days' gestation (P less than 0.01). No significant changes in renal blood flow were detected.

Proper use of skin tests with food extracts in diagnosis of hypersensitivity to food in children

Abstract: This study was undertaken to determine the proper use of skin tests with food extracts in diagnosis of hypersensitivity to food in children. Cutaneous reactions evoked by graded amounts of food extracts were compared with results of double-blind food challenge and in vitro release of histamine from leucocytes. A 3 mm or greater weal reaction in skin tests by puncture technique using food extracts of 1:20 w/v concentration was found to indicate the degree of hypersensitivity likely to be associated with clinically significant hypersensitivity reactions to food. Proper use of this simple technique will facilitate accurate diagnosis of food hypersensitivity in children by identifying the group among whom all positive reactions to food challenges will be found. Nevertheless, double-blind food challenge is essential to establish a diagnosis of symptomatic hypersensitivity to food.

Hyponatremia and central pontine myelinolysis.

Abstract: Autopsy in a patient with severe hyponatremia showed central pontine myelinolysis. Review of our patients with central pontine myelinolysis and those described in the English literature to date disclosed that 61 percent had documented hyponatremia. While the exact mechanism involving hyponatremia and central pontine myelinolysis cannot be defined, a circumstantial relationship is apparent. The purpose of this paper is to emphasize this relationship and to suggest that the possibility of central pontine myelinolysis be considered in any patient with hyponatremia and neurologic dysfunction.

The induction of hapten-specific T cell tolerance using hapten-modified lymphoid membranes. II. Relative roles of suppressor T cells and clone inhibition in the tolerant state.

Abstract: The cellular nature and specificity of suppressor cells and the mechanisms of tolerance to 2,4-dinitrophenyl-l-fluorobenzene (DNFB) in mice was investigated. Mice tolerized with hapten-modified self membrane, i.e. dinitrophenylated spleen cells (DNP-SC), generated suppressor cells as shown by their ability to transfer unresponsiveness to normal animals. Such suppressor cells were specific for DNFB as they did not interfere with sensitization of normal animals with 2,4,6-trinitro-1-chlorobenzene (picryl chloride). These suppressor cells were of the thymus-derived lymphocyte (T cell) lineage as (a) their activity was abolished by treatment with anti-Θ serum plus complement, and (b) these cells could not be raised in T cell-deprived mice. Kinetic studies of the development of tolerance showed discrepancies between the rate of induction of unresponsiveness in the donor (“phenotypic” tolerance) and the ability to transfer tolerance. One day after receiving 5 × 10 DNP-SC mice were phenotypically tolerant but could not serve as the donors of suppressor cells. 7 days after tolerization with DNP-SC mice were still fully tolerant and also contained suppressor cells, which were no longer demonstrable 14 days after tolerization when mice were still phenotypically tolerant. The ability to transfer tolerance was eliminated by pretreatment with cyclophosphamide (Cy). We postulate that two independent mechanisms of tolerance occur after tolerization with DNP-SC - the rapid induction of clone inhibition and the slower, transient induction of suppressor T cells. Cy had no effect on clone inhibition but eliminated the precursors of suppressor T cells.

Yolk sac carcinoma (endodermal sinus tumor): ultrastructure and histogenesis of gonadal and extragonadal tumors in comparison with normal human yolk sac.

Abstract: Human yolk sac carcinomas have been studied only twice with the electron microscope, and have never been compared at this level with normal human yolk sac. In the present study, the ultrastructural features of three primary ovarian yolk sac carcinomas, omental metastases from one of these, and a primary retroperitoneal yolk sac carcinoma in a male are reported, as are the ultrastructural findings in human yolk sac from normal 7- and 12-week gestations. The most prominent feature of the tumors is the presence of voluminous basement membrane material (the nature of which is confirmed by indirect enzyme-labeled antibody technique in one case) in both intra-and extracellular location, corresponding to the PAS-positive hyaline globules seen in these tumors by light microscopy. The tumor cells are also demonstrated to produce this material in tussue culture. Although basement membrane has not been described previously in normal human yolk sac at 8 and 10 weeks' gestation, it was present in the 7-week specimen which we studied, suggesting that its production may be a feature of only very young sac. Other ultrastructural findings are also similar in human yolk sac carcinoma, normal human yolk sac, and rodent yolk sac and yolk sac carcinomas. Thus, these studies confirm the suggested germ cell-derived yolk sac origin of the human tumor.

Fibromuscular dysplasia: multiple "spontaneous" dissecting aneurysms of the major cervical arteries.

Abstract: A patient presented clinically with acute bilateral carotid artery thrombosis and at autopsy had fresh dissecting aneurysms of all four major cervical arteries. The underlying vascular disorder was fibromuscular dysplasia. It is suggested that relatively minor injury to vessels already pathologically involved contributed to the multiple dissecting aneurysms in this patient.

Ventilatory response in myotonic dystrophy.

Abstract: Patients with myotonic dystrophy often develop respiratory failure caused by alveolar hypoventilation. Abnormalities in the ventilatory response to hypoxia and hypercapnia may explain this phenomenon. Accordingly, hypoxic and hypercapnic responses were measured in seven patients with myotonic dystrophy who had only mild respiratory muscle weakness. Hypoxic response was significantly reduced, while hypercapnic response was affected more irregularly. It is possible that the high incidence of respiratory failure in such patients is related to decreased hypoxic ventilatory response, occurring because of an underlying neurogenic deficit.

Endometrial carcinoma in women under 40 years of age: comparison of cases in oral contraceptive users and non-users.

Abstract: Women under 40 years of age rarely develop carcinoma of the endometrium, this age group comprising less than 3% of all cases in most large series. The Registry for Endometrial Carcinoma in Young Women Taking Oral Contraceptive Agents has recorded and studied 30 cases in women under 40 with a history of oral contraceptive administration, and these are compared with 25 cases in the same age group which were accessioned at the Armed Forces Institute of Pathology prior to the era during which these agents have been available, and with series reported in the literature totaling 137 cases with no contraceptive history. In the first group, special attention is paid to the 20 women who received sequential agents exclusively or predominantly, since the association with these agents (primarily Oracon) is much higher than would be expected from the fact that less that 10% of oral contraceptives used in this country are of the sequential type. An analysis of the three groups reveals a similar incidence of the various histologic types (primarily well differentiated tumors with a relatively favorable prognosis), the only difference being the presence of secretory features in 14 of 29 oral contraceptive users vs. only two of 25 women not taking these agents. Clinical and pathologic staging were also predominantly favorable, and comparable in all groups. There were, however, notably higher incidences of nulliparity, obesity, and sclerocystic ovaries--all features traditionally associated with endometrial carcinoma--in the patients not receiving oral contraceptives or receiving combined agents, suggesting that the group receiving sequentials may not represent the same constitutionally predisposed population. Only three of 55 women among our personally reviewed cases have thus far died of cancer (one in the contraceptive group and two in the non-user group) and all three of these had poorly differentiated tumors with myometrial invasion. The excellent prognosis for most patients in this age group is thus confirmed.

Effects of hypoxia on capillary density and fiber composition in rat skeletal muscle.

Abstract: Capillary density, fiber composition and myoglobin concentration were determined in skeletal muscle of Sprague-Dawley female rats. PIO2 for control (C) rats was 123 mm Hg; for hypoxic (H) rats the O2 concentration in air was lowered to 12.6% (PIO2=73 mm Hg) over 4 days and then kept at this level for 39 days. Body weight (BW) in C rats went from 182 to 258 g in 6 weeks. H rats showed an initial 13 g drop in BW but later gained weight at the same rate. A difference of 20 g was maintained between C and H rats. Five groups of about 10 rats each (3 C and 2 H) were studied by histochemistry using frozen samples from the tibialis anterior, gastrocnemius (medial head) and soleus muscles. 20 μm slices, cut transversely, were treated for alkaline phosphatase and ATPase after preincubation at pH's of 3.8 to 9.4 in order to visualize capillaries and typify fibers. In both C and H rats, capillary density decreased at the same rate with increasing BW, as a consequence of the increase in the size of the fibers resulting from growth. At the same BW capillary densities for a given muscle were not statistically different. No consistent differences in fiber composition were found in the soleus after exposure to hypoxia. In the gastrocnemius and the tibialis anterior, however, the percentage population of white fibers tended to be higher in the H rats than in the C rats, while the population of red fibers decreased. Myoglobin concentration was higher in the soleus, a muscle with a preponderant intermediate fiber population, than in the other two muscles. Hypoxia did not systematically affect myoglobin concentration.

Panic-fear in asthma: Requests for as-needed medications in relation to pulmonary function measurements

Abstract: Requests for as-needed medications and treatments (PRNs) by asthmatic patients scoring high, moderate, or low on the Asthma Symptom Checklist panic-fear category were studied for days when patients were matched at normal, intermediate, and subnormal levels of pulmonary function. Low panic-fear patients were the least likely to request PRNs regardless of the pulmonary function level. In contrast, high panic-fear patients often requested PRNs at each level of pulmonary function. Only moderate panic-fear patients made progressively more PRN requests on days when pulmonary functions were lower. These observations and others concerning the adverse influence of extreme panic-fear coping styles upon the treatment of asthma were discussed.

A Splenic Requirement for the Generation of Suppressor T Cells

Abstract: Tolerance to contact sensitization with DNFB may be induced by DNBSO 3 . This specific unresponsiveness may occur via one or both of two mechanisms — production of suppressor T cells or clone inhibition. We investigated the role of the spleen in this unresponsiveness. Splenectomized mice may be tolerized by i.v. injection of DNBSO 3 , but they are incapable of serving as donors of lymph node cells for transfer of tolerance to normal recipients. Kinetic studies indicated that the spleen must be present at least three days after tolerization in order to permit development of a significant number of suppressor cells in the peripheral lymph nodes. We interpret these results to indicate that 1) clone inhibition does not require the spleen, 2) the generation of suppressor T cells is dependent on the presence of the spleen, and 3) it is likely that tolerogens in this system induce suppressor cells in the spleen and some of these cells or their products leave the spleen to reach the peripheral lymph nodes.

A study of serum antibodies to isolated milk proteins and ovalbumin in infants and children

Abstract: Summary Serum antibodies to cow milk proteins and ovalbumin were measured quantitatively. Food hypersensitivity of the immediate type was determined to be present or absent by skin tests and double-blind food challenges. Elevated levels of antibodies to milk proteins in sera characteristic of infants fed cow milk were found to decline with age, so that sera from children who were 6 to 15 years of age (inclusive), not hypersensitive to food, had significantly lower levels than the infants. In contrast, sera from age-matched children, who were shown to have hypersensitivity to some food, were found to have levels of antibodies to milk proteins as elevated as in infancy. Hypersensitivity was not necessarily to milk but often to some other food. This persistence of greater antibody production to milk throughout childhood in those hypersensitive to some food indicates a fundamental difference from those without hypersensitivity to food, either in permeability, in immunological reactivity of the gut or in development of immunological unresponsiveness. Implications for pathogenesis of clinical disorders are discussed.

Junctional Transmission II. Presynaptic Mechanisms

Abstract: The sections in this article are: 1 The Quantum Hypothesis 1.1 Binomial and Poisson Statistics 1.2 Experimental Tests of Quantum Hypothesis 1.3 Measurement of Mean Quantum Content 1.4 Measurement of Release Probability and Number of Available Quanta 1.5 Experimental Values of Statistical Release Parameters at Various Junctions 2 Spontaneous Miniature Potentials 3 Synaptic Vesicles 4 Synaptic Delay 5 Depolarization and Release 6 Divalent Cations 6.1 Evoked Release 6.2 Calcium Entry 6.3 Spontaneous Release 7 Facilitation 8 Posttetanic Potentiation 9 Presynaptic Inhibition 10 Conclusion

Panic-fear: a personality dimension related to length of hospitalization in respiratory illness.

Abstract: In a prior study,1 development of a 15-item Minnesota Multiphasic Personality Inventory (MMPI) Panic-Fear scale was described which relates to the reported frequency of Panic-Fear symptoms (e.g., feeling scared, panicky, worried, and frightened) on the Asthma Symptom Checklist (ASC). High MMPI Panic-Fear scale scores describe fearful, highly emotional individuals who profess to have their feelings hurt more easily than others, to feel helpless and to give up easily in the face of difficulty. High-scoring asthmatic patients were found to have been prescribed more intensive oral corticosteroid regimens at the time of discharge from a residential treatment facility months after testing. This relationship was not attributable to differences in pulmonary function.In the present study, the results of the earlier research were expanded in several ways. First, the MMPI Panic-Fear scale was found to be related to an aspect of medical intractability, i.e., length of hospitalization, in two chronic respiratory illne...

Lingualized occlusion for removable prosthodontics

Abstract: Lingualized occlusion provides a useful combination of several occlusal concepts. Many advantages of anatomic and nonanatomic occlusions are retained. Adjustment to compensate for minor changes in vertical and centric relation is readily accomplished. Satisfactory occlusion is easily obtained, and balanced occlusion can be accomplished. The lingualized occlusal concept is not a panacea, and all other procedures still must be carefully executed.

Visualization of capillaries in skeletal muscle by the ATPase reaction.

Abstract: A simple and reliable technique for the visualization of capillaries in skeletal muscle of dogs, guinea pigs and rats is described. 10–20 μm frozen sections were incubated in a medium containing Ca2+ and ATP following acid preincubation (pH 3.8–4.2). The capillaries stained in black and were readily seen surrounding the muscle fibers. Serial sections were also treated for alkaline phosphatase. Values for capillary density using both methods were not different.

The comparison of denture-base processing techniques. Part II. Dimensional changes due to processing

Abstract: Some of the physical properties of three processing techniques of acrylic resin were tested. Tests included three-dimensional changes of the denture teeth and three-dimensional changes of the internal surface of the denture.

The Hippocampal Slice: A System for Studying the Pharmacology of Seizures and for Screening Anticonvulsant Drugs

Abstract: Interictal spikes with a configuration similar to that occurring in grand mal epilepsy were generated by the application of penicillin to a hippocampal slice preparation This slice preparation has potential value for screening anticonvulsant drugs and for studying epileptic activity The effect of anticonvulsant drugs on seizure activity was tested at concentrations comparable to reported clinical serum concentrations Phenytoin and diazepam were maximally effective at concentrations of 20 microgram/ml and 3-4 microgram/ml, respectively, in good agreement with their effective concentrations in clinical practice Phenobarbital was more potent (5 microgram/ml) and mesuximide (50% potent at 80 microgram/ml) was least effective

The mechanisms of lethal action of arabinosyl cytosine (araC) and arabinosyl adenine (araA).

Abstract: Certain D-arabinosyl nucleosides, notably arabinosyl cytosine (araC) and arabinosyl adenine (araA), are useful in the treatment of certain leukemias and some DNA virus infections, respectively. The compounds are lethal to animal cells and some bacteria. Despite extensive deamination, the parent nucleosides are transported within sensitive cells and phosphorylated to the mono-, di- and triphosphates. AraCTP and araATP are good specific competitive inhibitors of tumor cell of virus-induced DNA polymerases, competing with dCTP and dATP respectively. In addition to markedly inhibiting DNA synthesis, the aranucleotides enter newly formed DNA in internucleotide linkage. Sensitivity to the nucleosides appears to correlate with the relative ratio of formation of the triphosphate via a nucleoside kinase to degradation of the nucleoside via a nucleoside deaminase. Inhibition of the deaminase increases formation of the aranucleoside triphosphate in leukemic or virus-infected cells and markedly increases the toxicity of the nucleosides. Combinations of inhibitors of the deaminases and of the aranucleoside are being explored in clinical situations. In addition, the slow penetration of aranucleotides into cells has been observed and some of these 5'-phosphates are useful antiviral agents, e.g., against herpes virus in herpetic kiratitis.

Susceptibility of Propionibacterium acnes to Seventeen Antibiotics

Abstract: The in vitro susceptibility of 96 isolates of Propionibacterium acnes to 17 antibiotics was determined by utilizing an agar dilution technique. With the exception of the aminoglycosides, these organisms are susceptible to virtually all of the commonly used antimicrobial agents.

Psychological Issues in Bone Marrow Transplantation

Abstract: We studied the psychological and emotional problems experienced by seven children and their families who underwent bone marrow transplantation at the University of Colorado Medical Center from 1973 to 1975. These problems included (1) anxiety and depression relating to isolation, fear of death, and painful procedures; (2) an overdependence associated with a feeling of helplessness; (3) anger directed toward both the staff and the parents; (4) a reduced tolerance for medical procedures; and (5) periodic refusal to cooperate. Initially we had been concerned that patients might become agitated, psychotic, or even suicidal. These did not occur. Severe anxiety over bodily changes was not a problem. We did not encounter prolonged refusal to cooperate, refusal to remain in isolation, or drug addiction. Important aspects in management included an honest, straightforward, and direct discussion of all aspects of transplantation, including the potential complications and the risks of death from the underlying disease or from complications of transplantation. A firm but understanding approach to the patients appeared to be the most effective method to develop their continuing cooperation. The opportunity for patients to express verbally their fears of procedures and of death was essential. The donors needed help in working through their feelings of guilt if a transplant was not successful. The parents needed continuing psychological support for the many personal, social, and psychological difficulties which they had to face.

Effect of maturation on capillary density, fiber size and composition in rat skeletal muscle.

Abstract: SummaryCapillary density, fiber size and composition, were quantitated by histo-chemical methods in the tibialis anterior, soleus and gastrocnemius (medial head) of rats of different body weights. The capillary density was different in these muscles and it decreased with increasing body weight in a linear fashion due to a concomitant increase in the average cross sectional area of the fibers. This observation suggests that part of the variability in capillary density found in the literature is due to differences in body size. A change in muscle fiber composition with maturation was also observed. These were more marked in the tibialis anterior and in the soleus than in the gastrocnemius.The authors gratefully acknowledge the assistance of Ms. Sheila H. Eby.

Acute myocardial infarction with normal and near normal coronary arteries. Documentation with coronary arteriography within 12 1/2 hours of the onset of symptoms in two cases (three episodes).

Abstract: Three instances (in two patients) of acute myocardial infarction associated with arteriographically normal or near normal coronary arteries are reported. One patient with a lateral infarction had a normal coronary arteriogram and hypokinesia of the lateral wall. Another patient had two infarctions: (1) a transmural inferior-lateral infarction associated with occlusion of the most distal segment of the posterior descending branch of the right coronary artery, and (2) a transmural anterior-lateral-superior infarction associated with occlusion of the most distal segment of the left anterior descending coronary artery. Neither occlusion was consistent with the extent of infarction. Although coronary arteriography was performed as early as 12 12, 3 34 and 11 23hours, respectively, after the onset of symptoms of infarction in these three instances, the pathophysiologic features of the infarctions are obscure. Temporary occlusion of an epicardial coronary artery by spasm or platelet aggregates, or both, is suggested as a possible mechanism of the acute event.