123rc/medical_text huggingface dataset:
Expressional potency of mRNAs encoding receptors and voltage-activated channels in the postmortem rat brain. The stability and integrity of mRNAs encoding neurotransmitter receptors and voltage-activated channels in the postmortem rat brain was investigated by isolating poly(A)+ mRNA, injecting it into Xenopus oocytes, and then examining the expression of functional neurotransmitter receptors and voltage-activated channels in the oocyte membrane by electrophysiological recording. This approach was also used to assess the stability of mRNAs in brains that were incubated in oxygenated mammalian Ringer's solution for various lengths of time and from brains that were freshly frozen and then thawed at room temperature. Oocytes injected with mRNA from up to 21-hr postmortem brains gave large agonist- and voltage-activated responses, indicating that mRNAs encoding neurotransmitter receptors and voltage-activated channels are relatively stable in postmortem brain tissue. In contrast, oocytes injected with mRNA from brains incubated in Ringer's solution exhibited smaller responses, and oocytes injected with mRNA from tissue that was frozen and then thawed displayed very small or undetectable responses. Northern blot analysis using a nucleic acid probe for rat brain Na(+)-channel mRNA indicated that the size of the Na+ currents in injected oocytes reflected the levels of mRNA for Na+ channels in the different mRNA preparations. Thus, the expressional potency of mRNAs encoding neurotransmitter receptors and voltage-activated channels is quite stable in postmortem brains in situ, but it is reduced if the brains are kept in oxygenated saline, and freezing and thawing of tissue results in rapid degeneration of mRNA.
Giant chest wall tumor resulting from tissue reaction to foreign bodies. Three patients are reported in whom chest wall tumors developed 19 to 28 years after thoracoplasty and increased in size with time. The tumors could be removed operatively with good results. All tumors were composed of hematoma and necrotic material, and in all cases they revealed foreign bodies microscopically. Diagnosis and possible etiological factors are discussed.
The tangled web of coronary risk factors. Although epidemiologic, genetic, and pathophysiologic studies have shown that low-density lipoproteins (LDLs) are involved in the development of coronary artery disease, the standard measurement of LDL cholesterol comprises a number of separate components that may contribute in different ways to the disease process. Some of these components appear to be of particular pathologic importance. Intermediate-density lipoproteins (IDLs) and lipoprotein (a) are highly atherogenic species that each normally account for up to 10% to 15% total LDL cholesterol but may be disproportionately elevated in pathologic states and may therefore contribute disproportionately to coronary disease risk in certain patients. Recently, another subclass of LDL, characterized by relatively small particle size and increased density, also has been found to be associated with relatively increased risk of coronary disease. Furthermore, levels of this subclass, designated LDL-III, are linked to a number of interrelated hormonal and metabolic factors, each of which have also been associated with risk of coronary artery disease. These include male gender, postmenopause, abdominal adiposity, elevated triglyceride levels, increased levels of apolipoprotein B, and reductions in high-density lipoproteins (HDLs), particularly in the HDL2 subclass. Other studies have demonstrated that many of these factors are also commonly associated with relative insulin resistance and hyperinsulinemia. Thus, a lipoprotein profile characterized by a relative increase in LDL-III and a reduction in HDL2 is indicative of a constellation of metabolic features that defines a high-risk state and that makes it extremely difficult to single out one or more factors that are most directly involved in the disease process. Combinations of genetic and environmental factors acting on this "tangled web" of risk factors may account for much of the variation in coronary disease susceptibility found in the general population.
The influence of age vs peak serum concentration on life-threatening events after chronic theophylline intoxication. To identify risk factors for the development of seizures and cardiac arrhythmias after chronic, unintentional theophylline intoxication we monitored the clinical course of 72 consecutive patients referred to a regional poison center with chronic theophylline intoxication (serum theophylline concentration, greater than or equal to 167 mumol/L after protracted use). The median age of the sample was 47.5 years (range, 4 days to 91 years). Median peak theophylline concentration was 239 mumol/L, with a range of 167 to 722 mumol/L. A life-threatening event (LTE) occurred in 28 patients (39%) that included seizures in eight and a major cardiac arrhythmia in 22. The median peak (theophylline) of patients who had an LTE vs those who did not was 235.8 vs 238.7 mumol/L. However, the median age of patients with an LTE compared with those without an LTE was significantly greater (70.5 vs 18.0 years). Stratification of data by chronologic age revealed a stepwise increase in the frequency of LTE with advancing years: patients more than 75 years old had a 16.7-fold greater risk of LTE than patients less than 25 years old (95% confidence interval, 3.56, 77.5) despite comparable intergroup median serum (theophylline). These data suggest the primary determinant of LTEs after chronic theophylline intoxication is chronologic age. Elderly patients have an inordinately greater risk of LTE than younger patients. Peak serum theophylline concentration cannot predict which patients with chronic theophylline intoxication will have an LTE. Finally, these data indicate that theophylline should be used cautiously and with frequent monitoring of serum theophylline concentrations in elderly patients.
Recurrent tension headache in adolescents treated with self-help relaxation training and a muscle relaxant drug. Forty-eight adolescents suffering from recurrent tension headache participated in a controlled trial conducted in a high school setting. During the first treatment phase self-help relaxation training was compared with a waiting-list group. Following this phase a pharmacological regimen consisting of a muscle relaxant (chlormezanone) and placebo was superimposed on relaxation therapy in a double-blind crossover design. Each treatment phase encompassed a 5-week period. In addition to the evaluation of headache complaints, psychological distress among students was measured with respect to their experience of somatic complaints, depressive, anxiety and stress symptoms. Although self-help relaxation training significantly decreased the severity and annoyance of adolescents' headache besides their somatic complaints, the clinical improvement of headache was modest. The addition of chlormezanone did not help those who were nonresponders to self-help relaxation training. Finally, a set of pretreatment variables consisting of baseline headache severity and annoyance, experience of anxiety and daily life stress among adolescents could predict outcome of self-help relaxation therapy.
Metastatic tumors of unknown origin. The clinical appearance of metastatic lesions without an obvious primary source for the tumor is a common event. Tumor Registry figures and epidemiologic data grossly understate the actual frequency of unknown primaries, because primary sites are often "assigned" to patients on a best-guess basis without positive proof of a tumor's origin. In the majority of patients whose primary tumors have continued to elude detection, the extensive use of diagnostic imaging studies fails to produce information that alters the patients' clinical course. Rare exceptions will be cited, but these exceptions prove the general rule. Imaging studies should therefore be targeted for selected patients with disseminated malignancies in whom identification of their primary tumors could benefit quality of life or length of survival.
Coronary artery aneurysm without stenosis in association with Osler-Weber-Rendu disease--a case report. A fifty-three-year-old woman presented with coronary artery aneurysm in association with Osler-Weber-Rendu disease (hereditary hemorrhagic telangiectasia) manifested also by large pulmonary arteriovenous fistulas. The arterial dye dilution curves were unusually distorted owing to the right-to-left shunts. The coronary artery aneurysm was located in multiple sites but was not accompanied by stenotic lesions. Coronary artery aneurysm without stenosis is a rare pathologic state and has not been previously reported in association with hereditary telangiectasia.
Central adenoid cystic carcinoma of the mandible. A patient with adenoid cystic carcinoma arising centrally within the mandible, a rare location for this malignant salivary gland tumor, is described. Current concepts regarding the etiology, diagnosis, histology, and treatment of central intramandibular salivary gland tumors are discussed and the literature is reviewed.
Urinary retention due to sacral myeloradiculitis: a clinical and neurophysiological study. We report 5 cases of sacral myeloradiculitis presenting with transient urinary retention. Neurophysiological testing, including bulbocavernosus reflex, pudendal evoked response and external anal sphincter electromyography, was performed. Parasympathetic pelvic nerves, pudendal nerves as well as the spinal cord seem to be involved to various degrees in this infrequent disorder.
Preventive therapy of first gastrointestinal bleeding in patients with cirrhosis: results of a controlled trial comparing propranolol, endoscopic sclerotherapy and placebo. Propranolol and endoscopic sclerosis of esophageal varices are the two approaches currently used in prophylaxis of the first gastrointestinal hemorrhage in the cirrhotic patient. One hundred twenty-six cirrhotic patients with esophageal varices and no histories of bleeding were included in the trial regardless of the gravity of the cirrhosis or the size of the esophageal varices. Patients with hepatocarcinomas or other cancers, clearly impossible follow-up, previous treatment for portal hypertension or contraindication to beta-blockers were excluded. After randomization, 43 patients received propranolol twice daily at a dose reducing the heart rate by 25%; 42 patients were treated with intravariceal and extravariceal injections of Polidocanol; 41 control patients received vitamin K orally as placebo. The patients were seen at 3-mo intervals for 2 yr. On entry to the trial the three groups were comparable in terms of clinical and biological parameters, including size of esophageal varices (grade I = 51, grade II = 54, grade III = 17), Child-Pugh classification (A = 29, B = 61, C = 32) and the origin of cirrhosis (alcoholic in 79% of cases). Twenty-four patients bled (two bled in the propranolol group, nine bled in the endoscopic sclerosis of esophageal varices group and 13 bled in the placebo group). Actuarial estimates (Kaplan-Meier) of the time of onset of first bleeding showed that the differences were significant between propranolol and placebo (p less than 0.004) and between propranolol and sclerotherapy (p less than 0.03) but not between sclerotherapy and placebo.
Treatment of patients with isolated axillary nodal metastases from an occult primary carcinoma consistent with breast origin. The records of 42 patients who had axillary metastases compatible with a clinically occult breast primary were reviewed. Forty patients had mammography performed as part of their evaluations. Mastectomy yielded the primary tumor in one of 13 patients; biopsy yielded positive results in one of five. Among the 29 patients who did not undergo mastectomy, 16 received breast irradiation, and 13 were simply observed for signs of the primary tumor. For the patients who did not undergo mastectomy, the 5-year actuarial risk for appearance of a primary was 17% in the irradiated group versus 57% in the nonirradiated group (P = 0.06). Patterns of failure are correlated with stage and local and systemic therapy. The results affirm our belief that patients with axillary metastases histologically consistent with breast tumor should be treated identically to patients with similar nodal stages and proven breast primaries.
Caffeine and ventricular arrhythmias. An electrophysiological approach. Little information is known regarding caffeine's effect on the substrate supporting sustained ventricular arrhythmias. This prospective study evaluated the effect of coffee (275 mg of caffeine) on this substrate with programmed ventricular stimulation in 22 patients with a history of symptomatic nonsustained ventricular tachycardia, ventricular tachycardia, or ventricular fibrillation. Patients underwent electrophysiological testing before and 1 hour after coffee ingestion. Mean (+/- SEM) plasma caffeine level achieved after coffee consumption was 6.2 +/- 0.5 mg/L. Mean plasma catecholamine and potassium values were not altered significantly 1 hour following caffeine ingestion. The number of extrastimuli required to induce an arrhythmia was unchanged in 10 patients (46%), increased in six (27%), and decreased in six (27%). Rhythm severity was unchanged in 17 patients (77%), more severe in two (9%), and less severe in three (14%). In those patients with clinical ventricular arrhythmias, caffeine did not significantly alter inducibility or severity of arrhythmias, suggesting little effect on the substrate supporting ventricular arrhythmias.
Evaluation of the results of oesophagectomy for oesophageal cancer. The long-term results of standard techniques of oesophagectomy were examined in 127 patients with squamous cell carcinoma of the oesophagus. A near-total oesophagectomy with a cervical anastomosis was performed in 93 patients and an oesophagogastrectomy with an intrathoracic anastomosis was carried out in 34 patients. One hundred and eight patients had a curative oesophagectomy and 19 patients had a palliative resection. Eight patients received radiotherapy to the tumour bed. There were 15 deaths in hospital and the overall 5-year survival rate including perioperative deaths was 13.2 per cent. Survival was adversely affected by incomplete excision of macroscopic tumour (P less than 0.001), positive regional lymph nodes (P less than 0.05) and distant lymphatic metastases (P less than 0.02). The 5-year survival rate of patients with tumour invasion beyond the oesophageal wall (T3) and negative nodes was 20 per cent. Postoperative irradiation had no effect on the survival of patients with gross residual tumour. Complete clearance of microscopic tumour was achieved in 50 per cent of patients with T3 tumours and this group did not benefit from adjuvant radiotherapy. Survival in patients undergoing curative oesophagectomy with residual microscopic tumour, however, was significantly improved by irradiation of the tumour bed (P less than 0.01). These results suggest that the survival of patients can be increased significantly by the excision of all gross tumour and by identification of those who will benefit from local radiotherapy.
An assessment and care planning strategy for nursing home residents with dementia. Dementia is extremely common among nursing home patients, and it takes many forms. Accurate assessment by staff is crucial in providing appropriate care to these patients. Equally important is the ability to establish care priorities. Current staging models are so general, however, that their usefulness is limited. Thus, this paper proposes a strategy that, using basic assessment data, categorizes dementia residents according to four key determinants of care needs: activities of daily living status, behavioral problems, communication abilities, and physical transition.
Nonrandom chromosomal abnormalities in primary uveal melanoma. We report on 14 cases of clonal chromosomal anomalies in patients with primary uveal melanoma. An increased dosage of chromosome 8 or of parts of the long arm of chromosome 8 (8q) were detected in eight patients (57%). The smallest multiplied area of 8q appeared to be the region 8q2.1----qter. Monosomy of chromosome 3 was seen in six patients (43%), five of which were associated with anomalies of chromosome 8. Increased dosage of parts of chromosome 8q and loss of heterozygosity of chromosome 3, or the combination of both, seemed to be nonrandom for uveal melanoma and may distinguish it genetically from cutaneous malignant melanoma. Anomalies of chromosome 6, mostly resulting in additional material of 6p or a deletion of 6q, were found in six patients (43%). These anomalies, which seem to be common features of cutaneous malignant melanoma, were considered secondary rather than primary changes in uveal melanoma, since they were present only in subclones in most cases. Loss of the Y chromosome, restricted to tumor cells, was detected in four male patients, and loss of one X chromosome was detected in a female patient.
Physiologic and pathologic alterations associated with ultrasonically generated shock waves. Kidneys of 25 dogs were treated with ultrasonic shock waves and examined for both physiologic and pathologic changes. The number of pulses ranged from 2,000 to 8,000. The rate of the shock waves varied from one to 20 pulses per second. The difference in pulse rate did not affect the changes seen either acutely or in the delayed examination of the kidneys during the repair process. The physiologic and pathologic changes which occurred involved the renal tubule to a greater degree than the glomerulus. These alterations were resolving by one week following exposure to the shock waves.
Evolution of fundic argyrophil cell hyperplasia in nonantral atrophic gastritis. Fundic argyrophil cells were studied for a mean period of 68.7 months (range, 11-170) in 18 patients with fundic atrophic gastritis and achlorhydria. Initially, 12 patients had hyperplasia of the argyrophil cells, the severity of which was assessed using a semiquantitative classification based on the number of argyrophil clusters per square millimeter. At the end of the study, the degree of hyperplasia was unchanged in 9 patients, had decreased in 2, and had increased in 1; no significant increase in the number of argyrophil clusters, precarcinoid changes, or carcinoid tumors were observed and the high level of gastrinemia [mean, 4.8 (range, 1.9-8.1) times the upper limit for normal) did not change significantly. Of the 6 patients with no hyperplasia at the outset of the study, 4 continued without hyperplasia and 2 presented a low-grade hyperplasia at the 20th and 130th month. Gastrinemia increased significantly in the last patient and stayed normal in the other 5. This study argues in favor of the stable appearance of fundic argyrophil cells in patients with atrophic gastritis and stable gastrinemia.
Early diagnosis and surgical intervention of acute aortic dissection by transesophageal color flow mapping. To determine whether transesophageal color Doppler echocardiography (TEE) is useful for the early diagnosis and surgical intervention in acute aortic dissection, 57 serial patients with acute aortic dissection were examined. These patients were evaluated by TEE with either the single-plane probe (39 patients) or the biplanar probe (18 patients) just after admission. The intimal flap was detected in all patients, and there were 18 patients with type A dissection and 39 patients with type B dissection. The entry was visualized in 83% of type A dissection cases and in 90% of type B dissection cases. In two of 18 patients examined with the biplanar probe technique, the entry was detected in the longitudinal view only. Emergency operations were performed in 18 patients with type A dissection and in 10 patients with ruptured type B dissection. Twenty-nine of 39 patients with type B dissection were treated conservatively. The operative mortality rate of patients with type A dissection was 22%, and that of patients with ruptured type B dissection was 60%. The major advantage of TEE is its ease of application at the bedside or in the operating room, which allows immediate and accurate diagnosis of acute aortic dissection for emergency surgical intervention. Biplanar TEE provides additional acoustic windows, ease of spatial orientation, and more accurate visualization of entry. TEE is a useful and powerful diagnostic tool for acute aortic dissection, and by using this method, one may achieve a more rapid and aggressive surgical approach for patients with acute aortic dissection.
A strategy to reduce infant mortality. Using maternal mortality reviews as an historic model, fetal and infant mortality reviews are proposed to reduce infant mortality in the United States. The national program has three elements: 1) guidelines and direction from a national multidisciplinary steering panel and staff, 2) a technical advisory capacity to translate guidelines and to work with local and regional review committees, and 3) local review committees. A special emphasis, lacking in the limited efforts of previous infant mortality reviews, would be given to fetal mortality. The plan proposes a broad classification of potential contributing causes of mortality, from those related strictly to medical care, to the health system, and to individual patient factors. This will allow different and more effective targeted responses to factors identified locally. Critical impetus will be gained with The American College of Obstetricians and Gynecologists leading the effort from the private medical sector in partnership with national, state, and local public health agencies and other national medical societies.
Prevention of hypertension and vascular changes by captopril treatment. Treatment of female spontaneously hypertensive rats (SHR) and control Wistar-Kyoto (WKY) rats with captopril was carried out by the addition of the drug in the drinking water throughout pregnancy and lactation and after weaning. At 28 weeks of age, average systolic blood pressure of treated SHR was 113 +/- 3 mm Hg, which was below that of control SHR (188 +/- 3 mm Hg) and WKY rats (124 +/- 3 mm Hg). Body weight and heart rate of the SHR were not affected by the treatment. Tissue level of catecholamines was increased by captopril treatment in the superior cervical ganglia but remained unchanged in the plasma, heart, mesenteric arteries, and the adrenal glands of both SHR and WKY rats. Left ventricular weight, wall thickness, and internal diameter of the left ventricle in the SHR were reduced by the treatment. Morphometric measurements of the mesenteric arteries showed that vascular alterations present in the control SHR were prevented by the treatment. In the superior mesenteric artery and large mesenteric artery, smaller lumen size at maximal relaxation found in the control SHR was normalized to the level of the WKY rats. Hypertrophy of the medial wall in the superior mesenteric, large and small mesenteric arteries, and an increase in the number of smooth muscle cell layers in the large mesenteric artery of the SHR were prevented by the treatment. Perfusion study of the mesenteric vascular bed showed that reactivity of these vessels to norepinephrine was reduced, and sensitivity to norepinephrine (as determined by the effective dose that causes 50% of maximal response) was increased in the SHR by captopril treatment. Sensitivity of the tail artery in response to norepinephrine was not altered by the treatment. We conclude that long-term treatment with captopril of SHR before and after birth prevented the development of hypertension, structural and functional alterations of the mesenteric arteries, and cardiac hypertrophy.