shukoor65/lab-rag-model huggingface dataset:
Primary embryonal-cell carcinoma of the parietal lobe. Case report. A case of primary embryonal-cell carcinoma of the parietal lobe is reported. The unusually chronic presentation of such a malignant tumor is described. The atypical computerized tomography and magnetic resonance imaging characteristics of this lesion are presented. Review of the literature yielded no previous reports of a lobar embryonal-cell carcinoma. The rarity of intracranial germ-cell tumors presenting off the midline is discussed.
The role of enhanced vagal activity on ischemic ventricular tachycardia: pharmacologic basis of inefficiency. The effects of pharmacologic modulation of vagal activity on ischemic ventricular tachycardia were evaluated in 21 conscious dogs after permanent left anterior descending coronary artery (LAD) occlusion. Studies were done on spontaneous ventricular tachycardia (cycle length 383 +/- 100 msec, n = 21), 24 to 72 hours after LAD occlusion, and on inducible sustained monomorphic ventricular tachycardia (cycle length 251 +/- 30 msec, n = 6), 4 to 7 days after LAD occlusion. Edrophonium (1 mg/kg intravenously), a cholinesterase inhibitor, and methacholine (0.1 to 1 mg intravenously), a muscarinic agonist, had no significant effect on the rate or QRS morphology of either type of tachycardia, despite severe slowing of the sinoatrial rate. Similarly, atropine (up to 60 micrograms/kg intravenously) had no effect on the rate and QRS morphology of either type of tachycardia. In an attempt to enhance myocardial drug delivery to the ischemic and infarcted left ventricle, edrophonium (1 mg/kg) and methacholine (0.1 to 0.2 mg) were injected retrogradely through the great cardiac vein. This did not impart any significant therapeutic advantage over the systemic intravenous route. Sympathetic beta blockade did not affect the therapeutic outcome (n = 5) with either edrophonium or methacholine. It is concluded that direct or indirect enhancement of cardiac vagal activity has no effect on ischemic ventricular tachycardia in this model of subacute myocardial infarction. The lack of efficacy appears to be independent of myocardial drug delivery to ischemic ventricular site(s) and background sympathetic activity. Such a lack of efficacy may be caused by ischemia-mediated degeneration of vagal nerve terminals, by altered responsiveness of muscarinic receptors at infarcted arrhythmogenic myocardial sites, or both.
Surgical pathology of gastrinoma. Site, size, multicentricity, association with multiple endocrine neoplasia type 1, and malignancy. Specimens from the pancreas and duodenum of 26 patients with sporadic Zollinger-Ellison syndrome (ZES) and 18 patients with multiple endocrine neoplasia type 1 (MEN-1) and hypergastrinemia (17 with ZES) were screened immunocytochemically for gastrinomas. Location, size, multicentricity, and malignancy of the gastrinomas were evaluated. The MEN-1 patients had gastrinomas in the duodenum (nine of 18), pancreas (one of 18), and periduodenal lymph nodes (two of 18). No gastrinoma was identified in six patients. Most duodenal gastrinomas were multiple (five of nine) and smaller than 0.6 cm (six of nine). Lymph node metastases were present in eight of 12 patients. All 26 patients with sporadic ZES had a solitary gastrinoma; 14 were found in the pancreas and had a diameter greater than 2 cm. Ten patients had a duodenal gastrinoma, two with a diameter less than 0.6 cm. In two patients, only periduodenal "lymph node gastrinomas" were detected. Eighteen of the sporadic gastrinomas were malignant. These results suggest that duodenal location and multicentricity of gastrinomas are associated with the MEN-1 syndrome, and solitary gastrinomas, either in the pancreas or the duodenum, are predominantly seen in sporadic ZES.
A method for allocation of hearing handicap. A three-stage method is proposed for allocation of hearing handicap. First, for a given injury or noise exposure period, the percentage of loss allocable for each ear is calculated as a simple ratio of hearing change (after age correction) to final hearing level. Second, final hearing handicap is divided between the two ears using a formula derived from the 1979 AAO-HNS/AMA standard. The percentage of hearing handicap allocable to a given period for each ear is simply the product of that ear's scores from the first two steps.
Clinical pharmacology of calcium antagonists. There have been major advances in the understanding of the basic pharmacology of drugs acting upon voltage-dependent and receptor-activated calcium channels using patch-clamp techniques. The structure of the L channel is known and the (different) binding sites for various calcium antagonists have been identified using the methods of molecular biology. Although calcium slow-channel antagonists are very widely used in the treatment of hypertension, advances in the clinical pharmacology of angina and, to a lesser extent, cardiac arrhythmias, have not kept up with the basic research in molecular biology. All of the calcium antagonists in current use dilate arteries, and their therapeutic action largely depends on this property. There is evidence of differences in response between arteries and veins, and some degree of selectivity between vascular territories, but the goal of much more specific or localized vasodilation has not been achieved. The most prominent difference between the three main classes of antihypertensive drugs is the mild reflex increase of heart rate seen with the dihydropyridines and the bradycardia seen with verapamil. Most of the side effects of calcium antagonists are also based on vasodilatation, such as flushing and headache. The mild edema often seen with the dihydropyridines probably depends on the changes in capillary pressure brought about by arterial dilatation. Despite their undoubted efficacy as vasodilators, there are no studies thus far which allow any conclusions as to the long-term effect of calcium antagonists on the morbidity and mortality due to hypertension.
Efficient immortalization of luminal epithelial cells from human mammary gland by introduction of simian virus 40 large tumor antigen with a recombinant retrovirus. When defined in terms of markers for normal cell lineages, most invasive breast cancer cells correspond to the phenotype of the common luminal epithelial cell found in the terminal ductal lobular units. Luminal epithelial cells cultured from milk, which have limited proliferative potential, have now been immortalized by introducing the gene encoding simian virus 40 large tumor (T) antigen. Infection with a recombinant retrovirus proved to be 50-100 times more efficient than calcium phosphate transfection, and of the 17 cell lines isolated, only 5 passed through a crisis period as characterized by cessation of growth. When characterized by immunohistochemical staining with monoclonal antibodies, 14 lines showed features of luminal epithelial cells and of these, 7 resembled the common luminal epithelial cell type in the profile of keratins expressed. These cells express keratins 7, 8, 18, and 19 homogeneously and do not express keratin 14 or vimentin; a polymorphic epithelial mucin produced in vivo by luminal cells is expressed heterogeneously and the pattern of fibronectin staining is punctate. Although the cell lines have a reduced requirement for added growth factors, they do not grow in agar or produce tumors in the nude mouse. When the v-Ha-ras oncogene was introduced into two of the cell lines by using a recombinant retrovirus, most of the selected clones senesced, but one entered crisis and emerged after 3 months as a tumorigenic cell line.
Abnormalities of the foot in patients with diabetes mellitus: findings on MR imaging. The MR appearances of foot problems in patients with diabetes mellitus are illustrated. MR has been found to be effective in the diagnosis of osteomyelitis, the most common indication for imaging the feet of diabetic patients. MR has the ability to image numerous pathologic processes, especially subtle soft-tissue changes, that are not detectable with other imaging methods.
Accidental and intentional poisonings with ethylene glycol in infancy: diagnostic clues and management. Ethylene glycol has long been recognized as a potentially lethal poison and remains available today as automotive antifreeze and windshield deicer fluids. Ethylene glycol is rapidly absorbed from the gastrointestinal tract, with peak levels measured one to four hours after ingestion. Metabolism of the parent compound and the production of several organic acids are responsible for the metabolic acidosis observed in ethylene glycol poisoning. Target organ cellular damage is seen in the kidney, brain, myocardium, pancreas, and blood vessel walls. Renal tubular deposition of calcium oxalate crystals is felt to be responsible for the development of the severe renal injury which may accompany ethylene glycol ingestion. The clinical course is quite varied and includes inebriation, hematuria, cardiorespiratory compromise, and neurologic effects. Prompt diagnosis and initiation of treatment, including ethanol therapy and hemodialysis, is necessary to ameliorate the effects of ethylene glycol ingestion. Two cases of ethylene glycol poisoning, one accidental and one intentional, are reviewed.
Long term reduction in sodium balance: possible additional mechanism whereby nifedipine lowers blood pressure OBJECTIVE--To assess the changes in sodium excretion and sodium balance after withdrawal of long term nifedipine. DESIGN--Single blind, placebo controlled study in patients receiving fixed sodium and potassium intakes. SETTING--Blood pressure unit of a teaching hospital in south London. PATIENTS--Eight patients with mild to moderate uncomplicated essential hypertension who had been taking nifedipine 20 mg twice daily for at least six weeks. INTERVENTIONS--Withdrawal of nifedipine and replacement with matching placebo for one week. MAIN OUTCOME MEASURES--Urinary sodium excretion and cumulative sodium balance, body weight, plasma atrial natriuretic peptide concentrations, plasma renin activity and aldosterone concentrations, and blood pressure. RESULTS--During nifedipine withdrawal there was a significant reduction in urinary sodium excretion (day 1: -62.7 mmol/24 h; 95% confidence interval -90.3 to -35.0) and each patient retained a mean of 146 (SEM 26) mmol sodium over the week of replacement with placebo. Body weight and plasma atrial natriuretic peptide concentrations increased during the placebo period and seemed to be associated with the amount of sodium retained. Systolic blood pressure rose from 157 (9) to 165 (9) mmHg (95% confidence interval of difference -7.1 to 22.1) when nifedipine was replaced with matching placebo, and the rise seemed to be related to the amount of sodium that was retained. CONCLUSIONS--Nifedipine causes a long term reduction in sodium balance in patients with essential hypertension. This long term effect may contribute to the mechanism whereby nifedipine lowers blood pressure.
Distribution of porfiromycin in EMT6 solid tumors and normal tissues of BALB/c mice. The distribution of porfiromycin was studied in BALB/c mice bearing EMT6 mammary tumors. The levels of 3H in blood and most tissues peaked approximately 15 minutes after intraperitoneal injection of [3H]porfiromycin. The levels of radioactivity present in most of the tissues and in the tumors were similar at 4 hours and 24 hours after administration. Most of the normal tissues showed uniform, low grain densities when analyzed by autoradiography; the liver and the small intestine had the highest labeling densities. Only kidney, bladder, and tumor showed differential distributions of grains from [3H]porfiromycin. In the kidney, higher grain counts were found in cortex than in medullary regions; grains were uniformly distributed within each region. In the bladder, the highest labeling densities were found in regions near the lumen. Tumor regions that had some necrotic features or regions of necrosis that included some viable cells showed higher labeling intensities than healthy-looking tumor regions, probably because the abnormal microenvironments in these regions led to increased rates of activation of porfiromycin to electrophilic species. These findings show that porfiromycin can reach and be activated in tumor regions containing cells resistant to many chemotherapeutic agents and to x rays. The results also support the concept that agents such as porfiromycin can target cells in specific microenvironmental subpopulations of solid tumors.
Electrophysiologic study in acute lead poisoning. A 2-month-old girl with acute lead poisoning demonstrated electrophysiologic evidence of neurotoxicity. Motor nerve conduction studies of the median, ulnar, peroneal, and posterior tibial nerves revealed both axonal and demyelinating neuropathy. Somatosensory evoked potential studies of median and posterior tibial nerves demonstrated evidence of cortical involvement. Brainstem auditory evoked potential study disclosed the possibility of acoustic nerve involvement but no evidence of a brainstem lesion. Postmortem examination revealed cerebral edema and focal segmental demyelination of the median nerve.
Pericardial cyst with partial erosion of the right ventricular wall. A case of pericardial cyst with partial erosion into the anterior wall of the right ventricle is presented. Cardiopulmonary bypass was necessary for excision of the cyst. This report helps to alert surgeons of the possible need for cardiopulmonary bypass during the removal of some pericardial cysts, especially in patients with signs and symptoms of infection and in whom preoperative imaging fails to show distinct margins between the cyst and cardiac structures.
Current perception threshold screening for carpal tunnel syndrome. Screening for the onset of carpal tunnel syndrome (CTS), which is associated with excess ergonomic stresses of the wrist and hand, is a major concern in occupational medicine. CTS questionnaires, physical examinations, and quantitative sensory function determination through neuroselective current perception threshold (CPT) measurements were obtained from the median digital nerves of 16 assembly line workers who were symptomatic with hand pain. Median nerve evaluations by CPT detected sensory abnormalities in 75% of the workers, and abnormalities in 50% of the workers were detected by clinical evaluations (p less than .05, df = 22). CPT abnormalities were characterized as "hypoesthetic" in 25% and hyperesthesic in 42% of the workers. The noninvasive, nonaversive CPT technique provided sensitive and easily obtained quantitative measures. Regular use of this procedure in the occupational setting may assist in preventing the development of advanced CTS for it provides early detection of median nerve abnormalities.
Philadelphia-negative (Ph-) chronic myeloid leukemia (CML): comparison with Ph+ CML and chronic myelomonocytic leukemia. The Groupe Francais de Cytogenetique Hematologique. To better understand the Philadelphia-negative (Ph-) chronic myeloid leukemia (CML) and its relationships with Philadelphia-positive (Ph+) CML and chronic myelomonocytic leukemia (CMML), a study was undertaken by the Groupe Francais de Cytogenetique Hematologique. Thirty-five Ph- CML patients were investigated and compared with 55 chronic phase Ph+ CML and 100 CMML patients. There were 12 M-BCR positive (M-BCR+) and 23 M-BCR negative (MBCR+) patients. No clinical or biologic differences were found between Ph+ and Ph-, M-BCR+ patients. In the Ph- group, M-BCR+ and M-BCR- patients differed significantly in age (47.7 +/- 6.6 v 67.0 +/- 6.1 years, respectively; P = .001), leukocytosis (153.4 +/- 135.1 v 58.5 +/- 37.7 10(9)/L, P = .002), relative monocytosis (1.8% +/- 1.2% v 5.6% +/- 1.4%, P = .048), absolute basophilia (8.5 +/- 9.7 v 0.9 +/- 1.5 10(9)/L, P = .001), percentage of immature myeloid precursors (IMP) in peripheral blood (29.0% +/- 9.5% v 15.3% +/- 8.1%, P = .001), and percentage of erythroblasts in bone marrow (BM) (6.5% +/- 3.5% v 14.6% +/- 3.6%, P = .001). Karyotypic abnormalities other than the Ph chromosome occurred in 0 of 12 M-BCR- at diagnosis and 7 of 23 M-BCR- Ph- CML (P = .033). None of the 13 investigated BCR- patients had detectable BCR/ABL transcripts using polymerase chain reaction (PCR) and none had an N-RAS mutation. Cytologic findings showed a marked morphologic difference between M-BCR+ and M-BCR- patients, especially in the monocytic lineage. Dysmyelopoietic features in CMML and M-BCR- patients were very similar, and the differences were of quantitative order only. Using four criteria (monocytosis, percentage of IMP, basophilia, and percentage of erythroblasts in BM), patients could be divided into typical and atypical CML and this classification correlated well with molecular findings. We conclude that, while Ph-, M-BCR+, and Ph+ CML are identical diseases, Ph-, M-BCR- CML, and CMML have many similarities and might be only different aspects of a same entity.
Effect of cisapride on chronic idiopathic constipation in children. The efficacy of cisapride, a new prokinetic drug, as a treatment for chronic functional constipation of childhood was studied in 20 constipated children. Each subject had a stool frequency less than 4/week and/or total gastrointestinal transit time greater than 33 hr and was randomly assigned to double-blind treatment with either cisapride (N = 10) or placebo (N = 10) for 12 weeks. Stool habits, total gastrointestinal transit time, and anorectal motility were evaluated in all children before and at the end of the treatment period. Cisapride significantly increased stool frequency from 1.2 +/- 0.6 to 5.1 +/- 1.9 stools/week (mean +/- SD; P less than 0.05), whereas the lesser effect of placebo was not significant (1.2 +/- 0.8 to 2.8 +/- 0.8 stools/week; P = 0.4). Both treatments significantly (P less than 0.05) decreased laxative or suppository use. Total gastrointestinal transit time was decreased by cisapride (90.8 +/- 9.2 hr to 57.2 +/- 20.2 hr; P less than 0.05) but was not affected by placebo. Anorectal manometry showed that cisapride, but not placebo, significantly decreased the rectoanal inhibitory reflex threshold and the conscious rectal sensitivity threshold. It is concluded that cisapride improves gastrointestinal motility and bowel habits in children with chronic idiopathic constipation and may be useful in the management of some children with this disorder.
Procurement and transplantation of colonized cadaver skin. Cadaver skin is an important adjunct to burn care. This study was designed to measure the percentage of its contamination prior to grafting and to determine the clinical safety of its use. Cadaveric homografts from 19 donors were harvested, frozen, thawed, and used as a biological dressing. Cultures were obtained at the time of harvest, after incubation in antibiotics, and at actual transplantation. The homografts were 43 per cent, 68 per cent, and 50 per cent contaminant-free, respectively. Two of 14 patients lost their homografts due to infection. However, no patient developed an infection or lost the homograft due to an organism identified during the pretransplantation processing. Therefore, contaminant-free and slightly contaminated cadaver skin can be used safely as homografts.
Thrombosis in systemic lupus erythematosus: a French collaborative study. A retrospective study was undertaken of 120 children with systemic lupus erythematosus (SLE) seen in Paris and its immediate suburbs who fulfilled at least four of the American College of Rheumatology diagnostic criteria for SLE, and in whom the disease was diagnosed before the age of 16 and between January 1975 and December 1987. Eleven of these children (eight girls and three boys) all more than 10 years of age (mean follow up 8.1 years; range 3-13) had thrombotic episodes (9%). Thrombosis was one of the presenting signs in seven patients; in five it was associated with typical symptoms of SLE, and in the other two the thrombotic episode was isolated and diagnosis of SLE was delayed one and three years. Of a total of 16 thrombotic episodes (six of which were recurrent), 14 involved the leg veins, and in four there was associated pulmonary embolism. There were two episodes that affected cerebral arteries. The American College of Rheumatology diagnostic criteria for SLE as well as the incidence of lupus anticoagulant, positive direct Coombs test, and vasculitis in this group of patients was compared with the incidence in patients with SLE but no thrombosis. Only lupus anticoagulant was significantly associated with thrombotic episodes: eight of 11 (73%) of patients with SLE and thrombotic (arterial or venous) episodes had lupus anticoagulant compared with only 10 of 74 patients (14%) with no history of thrombotic events in the same age group.
Stimulation of atrial natriuretic peptide and vasopressin during retrograde mitral valvuloplasty. Acute mitral obstruction may lead to an increase in atrial natriuretic peptide (ANP) due to increased atrial pressure and a large increase in arginine vasopressin (AVP) due to simultaneous arterial and ventricular baroreceptor unloading. We measured ANP and AVP concentration after transseptal puncture and during percutaneous retrograde mitral balloon valvuloplasty (PRMV) in 11 patients (mean age 57 +/- 12 years; nine women) with mitral stenosis and congestive heart failure. Atrial septal puncture per se resulted in a significant increase in ANP and AVP without a significant change in aortic pressure. Subsequent PRMV led to a further increase in ANP, a transient decrease in aortic pressure from 89 +/- 7 to 45 +/- 4 mm Hg, and a large (fivefold) increase in AVP. ANP and AVP were no longer different from baseline values 18 to 24 after the procedure. This study suggests that transseptal puncture and acute mitral obstruction are major stimuli to ANP release and that combined unloading of arterial and left ventricular mechanoreceptors is a very potent vasopressinergic stimulus.
Cytokine messenger RNA stability is enhanced in tumor cells. Hematopoietic growth factors are produced by a number of human tumors. We extracted RNA from selected human tumor cells known to produce at least one hematopoietic growth factor and found high levels of abnormally stable cytokine messenger (m)RNA. Half-life experiments performed after preventing RNA synthesis by exposing cells to actinomycin D before RNA extraction showed stabilization of cytokine messages in tumor cells in liquid culture as well as in human tumor xenografts grown in mice. Exposure to the phorbol ester phorbol 12-myristate 13-acetate (TPA) caused enhancement of granulocyte-macrophage colony-stimulating factor (GM-CSF) message level in lung cancer cells and in control fibroblasts but elevated levels persisted far longer in the tumor cells. In normal cells, an AU-rich sequence in the 3' untranslated region of cytokine mRNAs confers lability to the message. Although a beta-globin gene expression vector containing this region appears to produce unstable mRNA in lung cancer cells, cytokine mRNAs, which also contain this sequence, are very stable in the tumors we studied. This may indicate that another region of the cytokine mRNA molecule is of greater importance than the AU-rich region in determining mRNA stability in tumor cells.