shukoor65/lab-rag-model huggingface dataset:
Hypertension profiling by total body water (TBW) determinations in patients on chronic hemodialysis. Hypertension is an important risk factor in hemodialysis patients. Fluid overload and increased peripheral resistance are considered the two main causes. We studied the relation between volume state and blood pressure in 18 hemodialysis patients. Actual total body water (aTBW) was measured as tritium space and "ideal" total body water (iTBW) by an anthropometric method. The difference between aTBW and iTBW was considered a measure of fluid excess or deficit. Twelve patients were overhydrated, 5%-23%. Their predialysis blood pressure was significantly correlated to their degree of fluid excess; systolic BP:r = 0.71, p = 0.03, diastolic BP:r = 0.73, p = 0.02, mean arterial BP:r = 0.76, p = 0.03. Five of these patients had multiple antihypertensive drugs instead of adequate ultrafiltration. Five patients had a fluid deficit of -3 to -13% and hypertension due to vasoconstriction. Four of these were adequately treated with antihypertensive drugs but had exaggerated ultrafiltration. TBW determination with tritium is simple to perform and gives information on the volume state and thereby on the cause of hypertension in hemodialysis patients. Based on this, appropriate treatment can be chosen.
Teicoplanin pharmacokinetics in intravenous drug abusers being treated for bacterial endocarditis. The pharmacokinetics of teicoplanin were determined after multiple 30-min intravenous infusions of 10 to 15 mg/kg every 12 to 24 h in 11 intravenous drug abuse (IVDA) patients being treated for bacterial endocarditis. Multiple serum samples were obtained over 7 to 14 days. Twenty-four-hour urine collections were obtained on days 1 and 5. Serum concentration-time data were analyzed by using multiple-dose pharmacokinetic analysis (NONLIN84). Results were compared with pharmacokinetic parameters derived from previous studies in normal healthy volunteers following multiple intravenous infusions of teicoplanin (3 to 6 mg/kg/day). Total and renal clearances of teicoplanin in IVDA patients were found to be significantly greater and more highly variable than those observed previously in normal healthy volunteers. As a result, predicted steady-state trough concentrations in serum may vary up to fivefold. The mechanism responsible for this variation appears to be related to the glomerular filtration rate. In IVDA patients, individualized teicoplanin dosage may be required in the treatment of bacterial endocarditis.
Nutritional model of hepatocarcinogenesis. Rats fed choline-devoid diet. Rats fed a choline-devoid diet as the sole treatment develop hepatocellular carcinomas, the pathogenesis of which appears to reside exclusively in effects of the diet on the liver. Among the latter, most prominent is the induction of repeating cycles of liver cell injury, death, and regeneration. Two other models have been described recently in the literature, in which development of hepatic neoplastic lesions occurs after protracted periods of liver cell injury, death, and regeneration, without exposure of the animals to chemical carcinogens. The possibility is considered that an abnormal increase in cell turnover may result in all of the genomic alterations that are required for initiation, promotion, and neoplastic transformation of liver cells in these models of hepatocarcinogenesis. The possible involvement, in the same models, of endogenously initiated liver cells also is discussed briefly.
The limited potential of special ambulance services in the management of cardiac arrest For six months a survey was made of all the patients in the Nottingham District Health Authority who died or who were brought to hospital after a cardiac arrest outside hospital. During this period just under half of the emergency ambulance shifts were covered by specially trained crews with defibrillators. During the study period the ICD coding of death certificates indicated that 894 (25%) of the 3575 deaths were due to ischaemic heart disease. During this period the ambulance service received 17,749 emergency calls, which included 445 patients who had cardiac arrests outside hospital. One hundred and forty seven of these patients were carried by ambulances equipped with defibrillators and resuscitation was attempted in 83. Seven patients survived to leave hospital. The special ambulance service was cost effective--a simple calculation suggests that the cost per life saved was approximately 2600 pounds, but it seems unlikely that special ambulance services will materially affect community fatality rates from ischaemic heart disease.
Induction of speech arrest and counting errors with rapid-rate transcranial magnetic stimulation. Six adult epileptic patients underwent rapid-rate transcranial magnetic stimulation (rTMS) at stimulation rates of up to 25 Hz with an 11-cm water-cooled round coil held flat on the scalp, centered over 15 different positions on each side of the scalp. The trains of stimuli were for 10 seconds while the patients counted aloud. rTMS centered over D5 or D7 induced reproducible speech arrest in all patients and counting errors in three when applied at lower intensities. There were no such speech disturbances by rTMS centered over the different positions on the right side. Intracarotid amobarbital test (IAT) demonstrated left hemispheric language dominance in all patients. Lateralization of speech arrest induced by rTMS correlated with the IAT results and may be helpful for noninvasive determination of hemispheric language dominance.
Evaluation of diagnostic methods for Helicobacter pylori gastritis. The authors evaluated the use of direct Gram-stained smears, 1- and 24-hour urease broth tests, histologic examination, and culture to detect Helicobacter pylori in 100 gastric biopsy specimens from 97 patients with epigastric symptoms. Twenty-six patients had positive cultures and 27 had H. pylori identifiable in hematoxylin and eosin-stained sections. The gastric biopsy specimens from the 29 patients with culture and/or histologic findings positive for H. pylori showed active gastritis in 27 cases (93%), compared with 26 cases (37%) without H. pylori (P less than 0.0001). Chronic gastritis was present in 25 cases (86%) with H. pylori and 40 cases (56%) without H. pylori (P less than 0.01). Twenty patients had positive Gram-stained smears. Fifteen patients had positive 1-hour urease tests, and 3 had delayed positive 24-hour urease tests. There were no false-positive Gram's stain results, three false-positive 24-hour urease tests, two false-negative histologic results, and three false-negative cultures (one inadvertently incubated anaerobically). The sensitivities of the methods were as follows: 62% for the 24-hour urease test, 69% for direct Gram's stain, 90% for culture, and 93% for histologic examination. The authors conclude that the urease test used in this study has low sensitivity and limited specificity; that the direct Gram-stained smear is a useful, highly specific, rapid screening test; and that the lengthier methods of culture and histologic examination have comparably high sensitivity for the definitive diagnosis of H. pylori gastritis.
Restriction of regional blood flow and diaphragmatic contractility. We have tested the hypothesis that the diaphragmatic head-to-head arterial anastomosis system should maintain adequate diaphragmatic function even during occlusion of some of its arteries. In six anesthetized open-chest dogs, left phrenic vein blood flow (Qphv) was measured by pulsed Doppler flowmetry. Contractility was measured by sonomicrometry in the left costal and crural diaphragm. The diaphragm was paced for 15 min by continuous bilateral supramaximal phrenic nerve stimulation. In five separate runs the following arteries were occluded at minute 5: 1) left phrenic artery, 2) internal mammary artery (IMA), 3) left phrenic artery and IMA, 4) descending aorta, and 5) descending aorta and IMA. Occlusion was then released at minute 10 of the run. In runs 1-3 there were no changes in contractility in costal or crural diaphragm and no changes in Qphv. However, in runs 4 and 5, Qphv decreased to 55.2 +/- 7.4 and 24.0 +/- 6.5% of control values, respectively. In run 4, percent maximum shortening from functional residual capacity (%LFRC) of the crural diaphragm decreased by 39.1%, while %LFRC of the costal diaphragm increased by 41.4% and abdominal pressure decreased by 47.0%. In run 5, abdominal pressure decreased by 53.5% and %LFRC of the crural and costal diaphragm decreased by 45.5 and 5.8%, respectively. Also relative postocclusion hyperemia was greater in run 5 (64.8%) than in run 4 (40.2%).
The decision to suggest screening lower gastrointestinal endoscopy: the effect of training. Primary care residency directors in the Southeastern US were surveyed to obtain information on training in lower gastrointestinal endoscopy (LGIE). All residents in a sample of programs were asked to complete a similar questionnaire. Response was 77% for family practice residencies and 60% for internal medicine residencies. Significantly fewer (43%) internal medicine residents reported receiving training in either 35 cm or 60 cm LGIE than family practice residents (77%). When asked if they would suggest LGIE to screen an asymptomatic patient, 67% of family practice and 84% of internal medicine residents replied affirmatively. Those residents who had received training were significantly more likely to suggest screening LGIE. The screening decision was not influenced by the specialty of the physician who supervised the resident training. Out-of-pocket cost to the patient was expected to be a major consideration in the screening decision, but this was not supported statistically. Greater availability of residency training in LGIE will likely increase its use in screening.
Successful term delivery by cesarean section in a patient with a continent ileocecal urinary reservoir. Childbirth in a mother with a continent urinary reservoir to our knowledge has not been previously reported. The effects of the gravid uterus on the reservoir are presented, as well as management of the pregnancy and delivery.
Base deficit as an indicator of significant abdominal injury. OBJECTIVE: To determine the relative predictive value of the arterial base deficit (BD) as an indicator of intra-abdominal injury (AI) and to compare BD with other indicators (chest injuries, pelvic fractures) of AI. DESIGN: Retrospective case-control analysis. SETTING: University of California San Diego Medical Center. MEASUREMENTS AND MAIN RESULTS: Between January 1985 and July 1988, 3,223 blunt trauma patients were admitted, with complete records available on 3,011. Using a "best fit" multiple logistic regression, BD less than or equal to -6 was the single most important indicator of AI (P less than or equal to .0001), and the odds ratio for AI increased with each category of increasing severity of BD. Admission hypotension, major chest injury, pelvic fracture, and field hypotension (in odds ratio order) also were significantly associated with AI. CONCLUSION: BD is a powerful indicator of AI. A normal BD does not exclude AI, but the presence of a BD less than or equal to -6 in a blunt trauma patient should be considered a strong indication for objective evaluation of the abdomen (ie, diagnostic peritoneal lavage).
Effects of therapeutic doses of heparin on thrombolysis with tissue-type plasminogen activator in rabbits. The objective of the study was to evaluate the ability of heparin to enhance the thrombolytic effect of recombinant tissue type plasminogen activator (rt-PA) and to prevent thrombus growth during and after thrombolysis with rt-PA. In the thrombolysis studies, three groups of rabbits were infused with rt-PA at a dose of 0.5 mg, 1 mg, or 2.5 mg over 3 hours, respectively. Rabbits in each group were randomized to receive, in addition to rt-PA, heparin, 20 or 60 antifactor Xa U/kg/h, or saline over 6 hours. The three doses of rt-PA produced the same extent of thrombolysis both in the two groups treated with heparin (34% +/- 6%, 52% +/- 7%, and 79% +/- 8% in the lower dose group; 39% +/- 6%, 49% +/- 4%, and 81% +/- 6% in the higher dose group) and in the group treated with saline (37% +/- 4%, 47% +/- 5%, and 84% +/- 7%). In the thrombus growth inhibition studies 0.5 mg of rt-PA was infused over 3 hours in each rabbit. In addition, the rt-PA-treated rabbits were randomized to receive heparin, 20 or 60 antifactor Xa U/kg/h over 6 hours, or saline. At the end of infusion, no statistically significant differences in thrombus growth were found in three groups of rabbits (54.8 +/- 7.4 micrograms and 52.4 +/- 12.1 micrograms in the low and high dose of heparin groups, respectively, and 59.4 +/- 10.4 micrograms in the saline group). In different experiments rabbits were randomized to receive heparin, 60 antifactor Xa U/kg/h, or saline at the end of the rt-PA infusion. In these experiments heparin inhibited thrombus growth more efficiently than saline (41.1 +/- 6.5 micrograms and 58.7 +/- 12.9 micrograms, respectively, P less than .05). In vitro experiments confirmed that heparin is unable to prevent fibrin accretion on the clots during lysis with rt-PA while both D-Phe-Pro-Arg-CH2-Cl (PPACK) and hirudin are able to prevent the accretion of fibrin. We conclude that the data obtained in these animal models do not support the concomitant use of heparin and rt-PA. However, heparin could be used successfully after rt-PA to inhibit thrombus growth.
Diarrhea associated with tube feeding: the importance of using objective criteria. Since the published incidence of tube feeding-associated diarrhea varies widely between 2.3 and 68%, and because commonly used definitions of diarrhea are subjective and imprecise, we determined the actual fecal output of malnourished patients during the first 6 days of tube feeding. Nine patients on the same isoosmolar formula were evaluated for diarrhea. Patients were interviewed daily as to whether they thought diarrhea was present or absent. Frequency of defecation was recorded, and stool was collected daily for weight. When assessed subjectively, the incidence of diarrhea rose from 11% on day 1, to 25% on day 4, and to 43% by day 6. The group (n = 4) complaining of diarrhea averaged 3.0 bowel movements per day, whereas those denying diarrhea (n = 5) averaged fewer than 0.2 bowel movements per day (p less than 0.01). Stool weight, however, plateaued for all patients by day 6 at 52.7 +/- 35.7 g of stool per day. No patient produced in excess of 250 g of stool per day. We suggest that traditional subjective measures for assessing diarrhea may be flawed and should not be relied upon when evaluating and treating tube feeding-associated diarrhea.
Orbital fractures: surface coil MR imaging. Twenty-six patients with orbital fractures diagnosed with plain radiography and computed tomography were examined with surface coil magnetic resonance (MR) imaging. Fifteen patients had blow-out fractures, and 11 had maxillofacial complex fractures. In all patients with blow-out fractures, the location of the fracture was precisely indicated by the presence of prolapsed orbital fat. Incarceration of the extraocular muscle or orbital fat was correctly diagnosed with MR imaging, which was less sensitive in depicting maxillofacial fractures but was useful in assessment of soft-tissue involvement. Postoperative follow-up MR studies provided valuable information about the cause of motility impairment. While T1-weighted images are useful for the detection of the fracture site, both T1- and T2-weighted images are usually necessary for evaluating soft-tissue lesions. The results of this study indicate that surface coil MR imaging is an important adjunct procedure in the diagnosis and treatment of orbital fractures.
Physiologic measurement of exercise and fatigue with special reference to chronic fatigue syndrome. Oxidative metabolism is the major source of energy for muscle activity, and maximal oxygen uptake (VO2max), the product of maximal cardiac output and maximal arteriovenous oxygen difference, indicates individual capacity for oxidative metabolism and performance of exercise by the large muscles. Strength, a function of muscle cross-sectional area, motor-unit recruitment, and neuromuscular coordination, is the ability to develop force in a single, brief, maximal-effort voluntary contraction of rested muscle. Weakness is a diminished ability of rested muscle to exert maximal force. Fatigue is a loss of maximal force-generating capacity that develops during muscular activity, likely originates within muscle itself, and persists until muscle is fully recovered. Individual perception of motor effort can be determined with standardized rating scales. These concepts are discussed in detail, their relevance to the pathophysiology of exercise in chronic fatigue syndrome is analyzed, and a general strategy of exercise evaluation pertinent to chronic fatigue syndrome is presented.
Intestinal and renal calcium-binding protein in rats with experimental short bowel syndrome. Intestinal calcium-binding protein (calbindin-D9K) and renal calcium-binding protein (calbindin-D28K) levels were measured by enzyme-linked immunoadsorbent assays in rats with short bowel syndrome induced by resection of about 85% of the small intestine. Rats with short bowel syndrome had significantly lower mucosal concentrations of calbindin-D9K (P less than 0.001) and a parallel reduction of both intestinal calcium absorption (P less than 0.001) and p-1,25-dihydroxyvitamin D (P less than 0.01) in spite of a general hypertrophy of the duodenal mucosa. Interestingly, the renal concentration of calbindin-D28K was significantly elevated (P less than 0.05) in rats with short bowel syndrome, a change apparently related to factors independent of vitamin D.
Visual recognition memory. Neurophysiological evidence for the role of temporal white matter in man. A novel event-related potential (ERP) elicited by a visuospatial recognition memory task was recorded in 20 patients with temporal lobe epilepsy using depth electrodes sited in the temporal lobes. The ERPs comprised two components, an N400 and a P600, and were similar in morphology to the previously reported ERP to verbal recognition memory tasks. The two ERP components in both verbal and visuospatial tasks were dependent on stimulus type and our data suggest that they do not simply represent delayed P300 ERP responses. In 17/20 patients robust, reliable bilaterally present ERPs were elicited by both verbal and visuospatial memory tasks. N400 amplitude was larger in response to novel stimuli, whereas P600 amplitude was larger to repeated stimuli. P600 amplitude was larger in the right temporal lobe to both visuospatial and verbal stimulus material. N400 and P600 latencies did not vary with task, stimulus type or side of recording. In 3/20 patients, no ERPs were elicited by either memory task. In all 3 cases, unilateral temporal white matter abnormalities were demonstrated by magnetic resonance imaging. Behavioural measures, expressed in the form of standardized accuracy scores, did not differ from those of a normal control group, and hence are unlikely to account for the abnormalities in ERPs. These results are discussed with reference to the primate visual recognition memory pathway and suggest that ERPs to recognition memory tasks are generated by an interaction between the two homologous inferotemporal recognition memory pathways.
Cardiovascular pharmacology of adrenergic and dopaminergic receptors: therapeutic significance in congestive heart failure. This review discusses the localization of adrenergic- and dopaminergic-adrenoceptors within the cardiovascular system and describes the cardiovascular and renal changes produced following the activation of these receptors by appropriate agonists. Whereas the role of alpha- and beta-adrenergic agents in the treatment of heart failure is well recognized, recent studies with dopamine (DA)-receptor agonists indicate that they offer a novel approach in the therapy of congestive heart failure. DA-adrenoceptor agonists reduce afterload by causing vasodilation and promote sodium excretion via direct activation of DA1-adrenoceptors located on renal tubules. Fenoldopam is a selective DA1-adrenoceptor agonist found to be effective in heart failure. It reduces afterload by causing peripheral vasodilation and produces natriuresis and diuresis. Dopexamine is a DA1- and beta 2-adrenoceptor agonist, and its efficacy in heart failure is due to its ability to provide mild inotropic support and cause a reduction in afterload. Ibopamine is a prodrug that is converted into its active metabolite, epinine. This compound activates primarily DA1- and DA2-adrenoceptors. It is effective in heart failure, and the mechanism progresses via DA1- and DA2-adrenoceptor-mediated reduction in afterload. Agonists of DA2-adrenoceptors reduce afterload by decreasing the release of norepinephrine and by reducing the levels of renin-angiotensin-aldosterone system. Since both of these systems are active in heart failure, ibopamine offers a rational approach for therapy. The present review addresses the concept of pharmacologic intervention in adrenergic and dopaminergic influence in the cardiovascular and renal systems to produce changes that are desirable for the pharmacotherapy of congestive heart failure.
Antihypertensive dose-response relationships: studies with the selective alpha 1-blocking agent terazosin. Terazosin is a selective alpha 1-adrenergic-blocking agent indicated for the treatment of hypertension. The aim of this multicenter study, performed in 256 patients with mild to moderate essential hypertension, was to define the dosing characteristics of terazosin (in the range of 1 to 80 mg) administered once daily. Patients were randomly assigned to placebo or active treatment groups; each group received 3 months of treatment, which comprised three ascending doses of terazosin, each administered for a 1-month period. As determined by conventional office measurements of supine diastolic blood pressure and by automated ambulatory blood pressure monitoring, there was a clear antihypertensive dose-response relationship for terazosin in the range of 1 to 5 mg daily. Except for the 80 mg dose, none of the doses above 5 mg (10 to 40 mg) appeared to provide additional efficacy. Both the office measurements and the monitoring data indicated that the ratio of trough (effect at the end of the dosing interval) to peak (maximum effect during the dosing interval) was at least 50% or greater during treatment with the 5 mg dose. Thus the 5 mg dose appeared to provide meaningful clinical antihypertensive efficacy and to sustain its effects throughout the full 24-hour period.