Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Coma”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83Linked to original sources
PubMed1988

The possible formation of a hydrogen coma around comets at large heliocentric distances.

An observational test--the detection of a hydrogen coma around comets at large heliocentric distances--is proposed for determining whether comets were formed by the agglomeration of unaltered, ice-coated, interstellar grains. Laboratory experiments showed that amorphous water ice traps H2, D2, and Ne below 20 K and does not release them completely until the ice is heated to 150 K. Gas/ice ratios as high as 0.63 are obtainable. Thus, if the ice-coated interstellar grains were not heated above approximately 110 K, prior to their agglomeration into cometary nuclei, the inward propagating heat waves should release from the comets a continuous flux of molecular hydrogen. This flux would exceed that of water molecules at approximately 3 AU preperihelion and approximately 4 AU postperihelion.

Astronomical Phenomena↗
PubMed2000

The RR Lyrae Star U Comae as a Test for Nonlinear Pulsation Models.

We use high-precision multiband photometric data of the first-overtone RR Lyrae star U Comae to investigate the predictive capability of full-amplitude, nonlinear, convective hydrodynamical models. The main outcome of this investigation is that theoretical predictions properly account for the luminosity variations along a full pulsation cycle. Moreover, we find that this approach, because of the strong dependence of this observable and of the pulsation period on stellar parameters, supplies tight constraints on stellar mass, effective temperature, and distance modulus. Pulsational estimates of these parameters appear in good agreement with empirical ones. Finally, a well-defined bump just before the luminosity maximum gave the unique opportunity to calibrate the turbulent convection model adopted for handling the coupling between pulsation and convection.

Journal Article↗
PubMedDate not supplied

Chill-coma temperature in Drosophila: effects of developmental temperature, latitude, and phylogeny.

We modify and apply a nonlethal technique for rapidly quantifying the cold tolerance of large numbers of Drosophila and other small insects. Flies are transferred to individual vials, cooled in groups in progressive 0.5 degrees C steps, and checked for loss of righting response (chill-coma temperature [T(cc)]). Flies recover quickly when transferred to ambient temperature, and thus this technique potentially can be used in selection experiments. We applied this technique in several experiments. First, we examined the sensitivity of T(cc) to developmental temperature. Drosophila melanogaster (Congo, France), Drosophila subobscura (Spain, Denmark), and Drosophila ananassae (India) were reared from egg to adult at 15 degrees, 18 degrees, 25 degrees, or 29 degrees C, transferred to 15 degrees C for several days, and then progressively chilled: T(cc) was positively related to developmental temperature, inversely related to latitude of the population, but independent of sex. The sensitivity of T(cc) to developmental temperature (acclimation flexibility) was marked: T(cc) shifted on average 1 degrees for each 4 degrees C shift in developmental temperature. Among 15 species of the obscura group of Drosophila, T(cc) varied from -0.1 degrees to 4.5 degrees C; T(cc) was inversely related to latitude in both nonphylogenetic and phylogenetically based ANCOVA (standardized independent contrasts) and was unrelated to body size.

Acclimatization↗
PubMed2003

Irreversible coma, ergotamine, and ritonavir.

We report the first case in the medical literature (to our knowledge) of a patient with human immunodeficiency virus infection who was being treated with ritonavir and developed signs of severe vascular involvement and irreversible coma after the administration of 3 mg of ergotamine tartrate.

Adult↗
PubMed2001

Evaluation of the traumatic coma data bank computed tomography classification for severe head injury.

This study determines the interrater and intrarater reliability of the Traumatic Coma Data Bank (TCDB) computed tomography (CT) scan classification for severe head injury. This classification grades the severity of the injury as follows: I = normal, II = diffuse injury, III = diffuse injury with swelling, IV = diffuse injury with shift, V = mass lesion surgically evacuated, or VI = mass lesion not operated. Patients with severe closed head injury were included. Outcome was assessed using the Glasgow Outcome Score (GOS) at 3 and 6 months. Four observers, two of them classifying the scans twice, independently evaluated CT scans. Of the initial CT scans of 63 patients (36 males, 27 females; age, 34+/-24 years), 6.3% were class I, 26.9% class II, 28.6% class III, 6.3% class IV, 22.2% were class V, and 9.6% class VI. The overall interrater and intrarater reliability was 0.80 and 0.85, respectively. Separate analyses resulted in higher inter- and intrarater reliabilities for the mass lesion categories (V and VI), 0.94 and 0.91, respectively, than the diffuse categories (I-IV) 0.71 and 0.67. Merging category III with IV, and V with VI resulted in inter- and intrarater reliabilities of 0.93 and 0.78, respectively. Glasgow outcome scores after 6 months were as follows: 19 dead (30%), one vegetative (2%), five severely disabled (8%), 17 moderately disabled (27%), and 21 good recovery (33%). Association measures (Sommers' D) between CT and GOS scores were statistically significant for all observers. This study shows a high intra- and interobserver agreement in the assessment of CT scan abnormalities and confirms the predictive power on outcome when the TCDB classification is used.

Adolescent↗
PubMed1976

Hypoglycaemic coma due to chlorpropamide: observations on twenty-two patients.

Twenty-two patients with chlorpropamide-induced hypoglycaemic coma were seen at a medical centre serving a region with a large geriatric population. The median age of the patients was 72; seven were over 80 and only one was under 60. Four patients died and in three of them death appeared to be connected with the hypoglycaemia. In two cases, the hypoglycaemia appeared in the postoperative period. Generally accepted contra-indications to the use of chlorpropamide were present in five of the eight patients under 70 and in four of the 14 patients over 70. If full precautions had been taken in presecribing chlorpropamide and if old age had been regarded as a contra-indication, the hypoglycaemia might have been prevented in 19 out of the 22 patients.

Aged↗
PubMed2001

Hyperammonemic coma caused by Providencia rettgeri infection in a child with prune belly syndrome.

OBJECTIVE: To report a case of hyperammonemic encephalopathy in the absence of liver disease caused by a urinary tract infection with a previously unreported organism. DESIGN: Case report. SETTING: Pediatric intensive care unit. Patient: Critically ill child who presented with hyperammonemic coma. INTERVENTION: Bladder drainage and antimicrobial therapy for the urinary tract infection. Measurements: Rapid resolution of the hyperammonemia. MAIN RESULTS: Rapid improvement in the patient's neurologic status and a return to his baseline function without neurologic deficit. CONCLUSIONS: Patients with abnormal urinary collecting systems who present with altered mental status should have a serum ammonia concentration sent as part of the initial evaluation. We have added Providencia species to the list of documented causative organisms in this rare association between urinary tract infections and hyperammonemia.

Journal Article↗
PubMed1986

The impact of computers on patient care and research: the pentobarbital coma experience.

Computer applications to patient care in an intensive care unit are examples the potential computers hold for health care, education, and research. The clinical application of a computer system to research and patient care in a selected research population, the pentobarbital coma study group, is described. The computer has been valuable in research for its data collecting and processing capabilities. It has also allowed the nursing staff to devote more time to patient care activities.

Computers↗
PubMed2003

Pentobarbital sodium coma for refractory intracranial hypertension.

Refractory intracranial hypertension (RICH) is defined as intracranial pressures that exceed 25 mm Hg for 30 minutes, 30 mm Hg for 15 minutes, or 40 mm Hg for 1 minute. RICH occurs in approximately 15% of patients with traumatic brain injury. If it is not aggressively treated, RICH can result in cerebral herniation and death. Pentobarbital sodium coma is a second-tier treatment that can be used to treat RICH. Understanding the principal mechanics of this therapy is key to the successful management of RICH and quality patient care.

Critical Care↗
PubMed1996

Morgagni: his book, vision and views on hepatic coma.

The study of pathological anatomy reached a culmination in the magnum opus of Morgagni, The Seats and Causes of Diseases. It represented an innovative way of looking at the patient and his illness, a change that Foucault described as occurring in the 18th century. Physicians saw symptoms penetrating the body and converging upon an organ. We suggest that Morgagni and his fellow workers derived their vision from the practice of visual perspective discovered by Italian Renaissance artists. Perceiving in three dimensional terms, Morgagni added spatial depth to our understanding of disease. His acute vision was brilliantly displayed in his views of hepatic coma. He was among the first to provide the clinical-pathological associations of acute liver failure. The limitations of gross morphology precluded a complete elucidation of the disorder.

Europe↗
PubMed1979

High-permeability membrane hemodialysis and hemofiltration in acute hepatic coma: experimental and clinical results.

A high-permeability polyacrylonitrile membrane was used for hemodialysis in experimental animals with induced liver ischemia and for acute treatment of 39 patients with fulminant hepatic failure. Measurements were made of amino acids and other relevant compounds; nine patients survived. In long-term studies, the polyacrylonitrile membrane was used for hemofiltration in ten clinical cases of fulminant hepatic failure and coma. Five patients, including two pregnant women, survived.

Amino Acids↗
PubMed2002

Natural transformation of Pseudomonas stutzeri by single-stranded DNA requires type IV pili, competence state and comA.

Pseudomonas stutzeri, in addition to being transformed by duplex DNA, is also transformed by the sense or antisense strand of the genetic marker employed (hisX(+)) or by heat-denatured chromosomal DNA. Transformation was absent in non-competent cells and in mutants defective for pilus biogenesis (pilA, pilC) and function (pilT) or DNA translocation into the cytoplasm (comA). Uptake of (3)H-thymidine-labeled single-stranded DNA was hardly detectable reflecting the 20- to 60-fold lower transformation compared to duplex DNA. The results suggest that the steps in natural transformation also accommodate single-stranded DNA and that DNA translocation from the periplasm into the cytoplasm is not necessarily coupled to the degradation of a complementary strand. Small DNA single-stranded fragments are thus not excluded from horizontal gene transfer by transformation.

Bacterial Proteins↗
PubMed1977

Can hepatic coma be caused by a reduction of brain noradrenaline or dopamine?

Intraventricular infusions of octopamine which raised brain octopamine concentrations more than 20 000-fold resulted in reductions in brain noradrenaline and dopamine by as much as 90% without affecting the alertness or activity of normal rats. As this reduction of brain catecholamines is much greater than any reported in hepatic coma, we do not believe that values observed in experimental hepatic failure have aetiological significance for the encephalopathy that ensues.

Animals↗
PubMed1998

Hypoplastic anaemia complicating myxoedema coma.

The case of a 68 year old women presenting in myxoedema coma is described. She was found to be anaemic with a haemoglobin of 8.2 g/dl. Further investigations showed a pancytopenia and a hypoplastic anaemia confirmed by bone marrow. The patient recovered and became euthyroid following initial treatment with intravenous tri-iodothyronine (T3) and later oral thyroxine (T4) replacement with resolution of pancytopenia and return of bone marrow to normal.

Aged↗
PubMed1993

Is coma morally equivalent to anencephalia?

In this article I contend that the tendency to equate coma with anencephalia is a mistake. A key idea here is that there is a type of "mental-state" predicate that is applicable to the comatose but not to anencephalics. One of the moral implications of this is that the concept of "brain death," its alleged popularity notwithstanding, is badly confused. Also, because anencephalics have no mental life, there are few moral grounds for hesitating to use anencephalics as organ donors.

Anencephaly↗
PubMed1992

Visual instrument image quality metrics and the effects of coma and astigmatism.

We examine subjective contrast and edge sharpness discrimination in the presence of different amounts of coma, astigmatism, and combinations of these two aberrations. We also examine the correlation between subjective results and objective image quality measures. These include the integral of the modulation transfer function (MTF) across the frequency range of interest (MTFa), the Strehl ratio, the variance of the wave-front aberration, and the radius of 84% encircled energy of the point-spread function (R84). For the target orientation that is most affected by the aberrations, we find that the MTFa and R84 give good correlation, while the Strehl ratio and the variance do not. In addition, we find that the MTFa correlates with subjective results for all target orientations. We discuss the implications of the results on the automated assessment of the image quality of visual instruments.

Astigmatism↗
PubMed1977

Citrulline as a diagnostic parameter and a major amino acid constituent of cerebrospinal fluid in hepatic coma.

Free amino acids of cerebrospinal fluid and serum in hepatic coma have been studied. Citrulline was found to form about 80% of the total free amino acids in cerebrospinal fluid, whereas serum contained slightly higher levels of tyrosine, methionine, phenylalanine and glutamine. The higher level of citrulline in cerebrospinal fluid may be attributed to the inhibition of argininosuccinic acid synthetase in this disease.

Argininosuccinate Synthase↗