Showing papers by "University of Colorado Denver published in 1978"

Urinary Diagnostic Indices in Acute Renal Failure: A Prospective Study

Abstract: A prospective analysis of the value of urinary diagnostic indices in ascertaining the cause of acute renal failure was undertaken. Our results show that in the setting of acute oliguria a diagnosis of potentially reversible prerenal azotemia is likely with urine osmolality greater than 500 mosm/kg H2O, urine sodium concentration less than 20 meq/litre, urine/plasma urea nitrogen ratio greater than 8, and urine/plasma creatinine ratio greater than 40. Conversely, a urine osmolality less than 350 mosm/kg, urine sodium concentration greater than 40 meq/liter, urine/plasma urea nitrogen ratio less than 3, and urine/plasma creatinine ratio less than 20 suggest acute tubular necrosis. A significant number of oliguric patients will not have urinary indices that fall within these guidelines. In this setting, urine sodium concentration divided by the urine-to-plasma creatinine ratio (the renal failure index) and the fractional excretion of filtered sodium provide a reliable means of differentiating reversible prerenal azotemia from acute tubular necrosis.

The possible influence of temporal factors in androgenic responsiveness of urogenital tissue recombinants from wild-type and androgen-insensitive (Tfm) mice.

Abstract: Tissue recombinants of epithelium and stroma from embryonic and neonatal urogenital rudiments derived from wild-type and femininized (Tfm/Y) mice were grown as grafts in intact male hosts and analyzed morphologically for androgenic response. When mesenchyme of embryonic wild-type urogenital sinus (UGS) was associated with epithelium from embryonic wild-type bladder (B), the epithelium developed into glandular structures resembling prostate. In the reciprocal recombinant (B mesenchyme + UGS epithelium) the response was mixed, half of the recombinants exhibited bladder morphology and half exhibited prostatic-like morphology. Vaginal-like histogenesis occurred in UGS recombinants of androgen-insensitive Tfm/Y mesenchyme and wild-type epithelium, while prostatic morphology developed in reciprocal recombinants of wild-type mesenchyme and Tfm/Y epithelium. These observations demonstrate (1) that the presence of wild-type mesenchyme appears essential for expression of androgen-dependent morphogenesis during embryonic periods; and (2) that Tfm/Y epithelium is capable of participating in an androgenic response. Conversely, in similar recombinants prepared with neonatal tissues, the presence of wild-type urogenital stroma may not be required for expression of certain androgen-dependent phenomena since maintenance of the height and cytodifferentiation of ductus deferens epithelium occurs even when this epithelium is associated with Tfm/Y urogenital stroma. It appears, therefore, that the requirement of urogenital epithelium for wild-type (androgen sensitive) stroma may vary temporally.

Caffeine enhancement of X-ray killing in cultured human and rodent cells.

Abstract: A 16 to 20 hr postirradiation incubation with caffeine enhances x-ray killing of rodent and human cells. Cells tested were Chinese hamster ovary (CHO-K1), lung (CHL), V79, mouse L, HeLa S3, human fibroblasts (AF288, TC171, FS9, CRL1166), and a human-hamster hybrid. The effect of caffeine on the x-ray survival curve of these cells was to remove the initial shoulder without significantly altering the mean lethal dose (D/sub 0/). This action can be achieved at caffeine concentrations which of themselves cause less than 15% killing. In randomly growing CHO-K1 cells the caffeine-sensitive process occurs with a half-time of 2 to 5 hr after irradiation. These experiments indicate the existence in human and rodent cells of caffeine-inhibited genome repair for x-ray damage.

Tumors arising in organ transplant recipients.

Abstract: Publisher Summary This chapter focuses on the tumors arising in organ-transplanted recipients. The chapter studies cancers in three groups of transplant patients: (1) those with inadvertently transplanted neoplasms, (2) those with cancers that arise de novo at some time after transplantation, and (3) those with tumors present before grafting. An important area of cancer research involves the transplantation of tumors in various animal species. Such experiments are usually performed in inbred strains to avoid histocompatibility differences between the donor's cancer cells and the recipient's immune system, which will usually result in rejection of the transplant. Transplantation across histocompatibility barriers usually necessitates the use of some type of immunosuppressive therapy, or the use of a congenitally immuno-deficient species, such as the nude mouse, which can accept grafts of human tumor tissue. Various possible causes of cancers include—alteration in immunity, oncogenic viruses, oncogenicity of the immunosuppressive agents, co-oncogenic effects of the immunosuppressive agents, potentially oncogenic medication, and genetic factors. Without immunosuppressive therapy, organ transplantation, resulting in restoration of health and long-term satisfactory organ function, is not possible. The chapter concludes that perhaps the genetic factors also play a role in determining which transplant patients are susceptible or resistant to the development of malignancy.

The Effects of Dietary Carbohydrate Content on Insulin Binding and Glucose Metabolism by Isolated Rat Adipocytes

Abstract: The effects of changes in the amount of dietary carbohydrate (CHO) on cellular insulin and glucose metabolism have been assessed in rat adipocytes. Feeding animals a 67% CHO (fat-free) diet resulted in decreased insulin binding but enhanced activity of both the glucose transport system and intracellular pathways of glucose metabolism. Feeding rats a 67% fat (CHO-free) diet resulted in decreased insulin receptors as well as decreased activity of the glucose transport system and intracellular glucose metabolism. Therefore, the in vivo insulin resistance caused by a high fat, low CHO diet seems to be adequately explained, since all aspects of insulin's cellular action were depressed. On the other hand, at first approximation, the increased in vivo insulin response caused by a high CHO diet appears contradictory to the observed decrease in insulin binding. However, a probable explanation for this apparent paradox is provided by the enhanced activity of the cellular insulin effector systems distal to the insulin receptor. Therefore, the increased in vivo insulin responsiveness after high CHO feedings is most likely due to post receptor increases in various aspects of glucose metabolism.

Adaptation to the Birth of a Down's Syndrome Infant: Grieving and Maternal Attachment

Abstract: Six cases, involving family adaptation to a Down's syndrome birth, illustrate variations in the countermovement between processes of parental grieving for a fantasied normal infant and attachment to a real handicapped infant. After initial grieving, there is likely to be some affective denial of disability, with a second wave of grieving inaugurated by a social smile which is dampened and by eye-to-eye contact which is less than expected. Implications for intervention are especially important in the light of our changing attitudes toward home care of the retarded.

On Fieller's Theorem and the General Linear Model

Abstract: The purpose of this note is to indicate that Fieller's Theorem can be expressed in the matrix formulation of the general linear model. The practical consequence is that one general computer program which can estimate the parameters and test the validity of a pertinent model, can also compute confidence limits for the ratios of any linear combinations of the parameters.

Exogenous progestogen and estrogen implicated in birth defects.

Abstract: A five-year study of the possible teratogenicity of exogenous female sex hormones included three case-control studies and one cohort study. The first case-control study disclosed an estimated relative risk of 8.41 and a highly significant difference in maternal hormonal exposure ( P P =.017) and 3.35 ( P ( JAMA 240:837-843, 1978)

Benzodiazepines and central inhibitory mechanisms.

Abstract: The effect of diazepam was evaluated on spontaneous activity and drug-and electrically-elicited inhibitions of neuronal activity. Doses of diazepam which did not change spontaneous firing rates markedly enhanced GABA-mediated inhibitions in rat cerebellum in situ and in tissue cultures of rat hypothalamus. The effects of diazepam were readily reversible, and could be antagonized by picrotoxin; no effect on glycine or norepinephrine-induced inhibition was seen. It is concluded that actions of diazepam are mediated, at least in part, by a specific increase in GABA-mediated inhibition in the central nervous system.

Insulin secretion in fetal and newborn sheep.

Abstract: The relationships between arterial plasma insulin, glucose, and fructose concentrations during the fed and fasted state were studied in seven fetal lambs and their mothers. A significant correlation between insulin and glucose concentration was noted in all fetal lambs and in their mothers. Fetal sensitivity to glucose, as measured by the slopes of the insulin-response curves, was equal to that of the adult although the fetal response was shifted to the left of the maternal. Glucose infusion in four fetal lambs caused significant insulin elevations but no early insulin response (phase I). Maternal fasting caused no alteration in glucose-induced response in the fetus. Similar glucose infusions in newborn and 1-mo-old lambs demonstrated significant early-phase insulin secretion. Basal insulin to glucose ratios were consistent with an adult pattern as early as 3 days after birth.

Reversal by triton WR-1339 of ethynyloestradiol-induced hepatic cholesterol esterification.

Abstract: RATS TREATED WITH ETHYNYLOESTRADIOL HAVE MARKED HYPOLIPIDAEMIA: serum cholesterol is decreased to 5%, triacylglycerol to 10% and phospholipid to 70% of control concentrations. Loss of serum cholesterol follows an exponential decay, with a half-life of 1.13+/-0.09 days. After 4 days of treatment, serum cholesterol concentrations remain relatively constant (ranging from 1 to 20mg/100ml) for at least 30 days. There is a concomitant 20-fold decrease in the d<1.21 fraction of serum proteins and a similar decrease in serum apolipoproteins as measured by sodium dodecyl sulphate/10%-polyacrylamide-gel electrophoresis. The activity of hepatic microsomal acyl-CoA-cholesterol O-acetyltransferase (EC 2.3.1.26) was significantly increased by ethynyloestradiol treatment (P<0.05). This activation caused hepatic cholesteryl esters containing mainly C(18:1) fatty acids to increase linearly as serum cholesterol concentrations decreased (r=0.9675, P<0.001). Triton WR-1339, a non-ionic detergent that inhibits lipoprotein catabolism, was used to estimate hepatic lipid secretion by measuring the increment in serum lipids after its administration. At 15h after Triton WR-1339 administration, serum cholesterol concentrations were increased equally in both control and ethynyloestradiol-treated rats. In contrast, the increment of serum triacylglycerol of treated rats was 40% of that found in control rats, indicating that ethynyloestradiol inhibits hepatic triacylglycerol secretion. Triton WR-1339 inhibited the oestrogen activation of hepatic microsomal acyl-CoA-cholesterol O-acyltransferase and restored hepatic cholesteryl ester concentrations to normal values. These data suggest that ethynyloestradiol and its pharmacological ;antagonist' Triton WR-1339 alter hepatic triacylglycerol secretion via a mechanism associated with changes in hepatic cholesterol esterification.

Emotional Expression in Infancy: II. Early Deviations in Down’s Syndrome

Abstract: A previous report (Emde, Kligman, Reich, & Wade, this volume) summarized our initial studies with emotional signaling in normal infants. This report discusses an example of a deviation in such signaling.

Emotional Expression in Infancy: I. Initial Studies of Social Signaling and an Emergent Model

Abstract: This story, one of description, began as a bothersome byroad in a research odyssey concerned with understanding emotional development, but it has now become an absorbing adventure in its own right. Our program started in what seemed like a direct and simple fashion, first with studies of babies who smiled and then with babies who cried. We studied these behaviors in multiple contexts, physiological, social, and developmental (Emde & Harmon, 1972; Emde, Gaensbauer, & Harmon, 1976), but then, as psychiatrists, we encountered a concern. In the course of our longitudinal studies, we became increasingly bothered by a nagging question: How did we know that what we were calling emotional in babies was related to the later emotional experience that older patients talk about and that we find so central in our clinical work? Obviously, the preverbal infant could not tell us how he felt. In using a variety of viewpoints to bear on this problem, we soon learned that defining or “indexing” emotions by physiological or situational correlates alone was unreliable and made little sense. But as we continued our longitudinal studies, both in the home and in the laboratory, we reassured ourselves with one view, firmly rooted in the naturalistic setting. When we concentrated on viewing emotions as expressions, as nonverbal communications, we were reassured because we found that facial expressions and other behaviors that we presumed to call emotional regularly communicated (1) feelings and (2) messages for caretaking and social interaction, and that both of these were meaningful for parents. Nonetheless, our observations were at the anecdotal-descriptive level, and we realized that more systematic efforts were needed.

Hemodynamic pattern resembling pericardial constriction after acute inferior myocardial infarction with right ventricular infarction

Abstract: Two patients with acute inferior myocardial infarction complicated by cardiogenic shock are presented. Cardiac catheterization 2 and 7 days after infarction, respectively, revealed a hemodynamic pattern resembling constrictive pericarditis. Right coronary occlusion proximal to the right ventricular marginal branches was present in both patients. Resolution of the constrictive hemodynamic pattern was demonstrated in the one survivor at repeat catheterization 7 weeks after infarction. The mechanism for constrictive hemodynamics in these patients is unclear.

Pharmacokinetics of acetaminophen in children.

Abstract: Acetaminophen absorption may occur at a somewhat greater rate in children if the syrup form is utilized. The overall plasma elimination of acetaminophen is somewhat slow in the neonate, but is comparable to that of adults in both children and adolescents, as judged by half-life determinations. This would suggest that the frequency of acetaminophen administration in children should be similar to the schedule recommended for adults and that a dosing interval of four hours should not result in drug accumulation. The question of a toxic quantity of acetaminophen for young children must remain open until adequate metabolic or retrospective toxicologic data become known. Since the volumes of distribution appear to be the same in both adults and children, the same dose should apply in both groups; currently, 10 mg/kg is considered to be both safe and effective for antipyresis.