123rc/medical_text huggingface dataset:
Clonotypic analysis of anti-acetylcholine receptor antibodies from experimental autoimmune myasthenia gravis-sensitive Lewis rats and experimental autoimmune myasthenia gravis-resistant Wistar Furth rats. A single immunization of Lewis rats with purified acetylcholine receptor (AChR) emulsified in adjuvant typically stimulates the production of oligoclonal AChR-reactive antibodies (as demonstrated by IEF) dominated by the IgG2a subclass, of moderate but clonotypically heterogeneous relative Ag-binding avidity, and capable of inducing symptoms of experimental autoimmune myasthenia gravis. Although similar immunization of Wistar Furth rats produces AChR-reactive antibodies with similar characteristics of clonotypic heterogeneity, avidity, and isotype expression, no detectable signs of AChR-dependent muscle impairment is observed. This contrasts the ability to induce impaired AChR function upon the passive transfer of pre-formed Lewis anti-AChR antibodies into naive Wistar Furth rats, suggesting that disease resistance in this model is not conferred at the level of the AChR itself. Moreover, if more aggressive immunization protocols are used (i.e., multiple injections of AChR), a transient breakthrough of AChR-dependent muscle dysfunction can be induced directly in the Wistar Furth strain indicating that the potential for the production of disease-causing antibodies does exist in the Wistar Furth repertoire. IEF analysis of Wistar Furth anti-AChR antibodies has revealed that hyperimmunization results in modified antibody clonotype expression that might explain changing expression of disease symptoms; however, explanations for the apparent "resistance" of Wistar Furth rats to disease induction are likely to be complex.
An implantable neurocybernetic prosthesis system. The neurocybernetic prosthesis (Cyberonics, Inc.) is an implantable, multiprogrammable pulse generator that delivers constant current electrical signals to the vagus nerve for the purpose of reducing the frequency and/or severity of epileptic seizures. The device is implanted in a subcutaneous chest pocket just below the clavicle, similar to cardiac pacemaker placement. The stimulation signal is transmitted from the prosthesis to the vagus nerve through a stimulation lead. The prosthesis can be programmed using any IBM-compatible personal computer with programming software and a programming wand. The electrodes used in the first group of patients were found to break at an unacceptable rate. Design modifications appear to have resolved this problem.
Sinus nodal dysfunction in young patients with long QT syndrome. Although sinus bradycardia and low heart rate with exercise have been found in some patients with long QT syndrome, systematic evaluation, including intracardiac electrophysiologic (EPS) tests of sinus node function, has not been reported. Records were reviewed of 14 children and adolescents (age 3 to 16 years) with long QT syndrome (mean QTc 0.51 second) who underwent noninvasive testing and intracardiac EPS because of syncope or cardiac arrest. The resting electrocardiographic (ECG) sinus heart rate was low for age in only 1 of 13 patients, while the lowest Holter-monitored sinus heart rate was abnormal in 4 of 12. The maximum exercise heart rate was abnormally low in 6 of the 12 who underwent exercise testing. For the EPS tests, the corrected sinus node recovery time (CSNRT) was long in 8 of 14 and the sinoatrial conduction time (SACT) was long in six of the nine in whom it was calculable. When both noninvasive and EPS indices are considered, 13 of the 14 patients had some type of sinus node dysfunction.
Interpleural analgesia after thoracotomy. We examined the effects of the following variables on interpleural analgesia after thoracotomy: addition of epinephrine to local anesthetic, thoracostomy drainage, two-catheter placement, and location of catheter tips. Twenty patients were randomized to have one catheter (paravertebral tip location) or two catheters (paravertebral and lateral thoracic wall tip locations). Interpleural catheters were sutured to the parietal pleura by the surgeon at time of wound closure. Patients were then randomly assigned to receive 20 mL of 0.5% bupivacaine with 1:200,000 epinephrine through the single catheter or 10 mL of 0.5% bupivacaine with or without 1:200,000 epinephrine through each of the two catheters while supine. Bupivacaine concentrations in whole blood and in thoracostomy drainage fluid were assayed by gas chromatography. Actual content of bupivacaine in the drainage fluid was calculated. Degree of analgesia was assessed by verbal numerical pain scores over the first 4 h and opioid demand thereafter. Addition of epinephrine to bupivacaine did not influence the degree of analgesia. Approximately 30%-40% of any administered dose of bupivacaine was lost via the thoracostomy tube over a 4-h period. There was no correlation between the true initial dose (100 mg minus thoracostomy drainage) and Cmax. Use of two catheters resulted in significantly less opioid requirements after an initial 8-h period. Failure to achieve adequate interpleural analgesia in postthoracotomy patients may be related to loss of anesthetic via thoracostomy drainage, presence of extravasated blood and tissue fluid in the pleural space, and possibly sequestration and channeling of flow of local anesthetic by restricted motion of an operated lung.
Chondrosarcoma of the head and neck. Chondrosarcoma is a malignancy rarely encountered in the head and neck. In an attempt to define this tumor's characteristics and response to therapy, all cases of chondrosarcoma treated at the University of Michigan over the past 25 years were retrospectively studied. Fourteen cases originating in the nose and paranasal sinuses, mandible, temporal bone, and larynx were reviewed. Aggressive surgical resection was the mainstay of treatment, and resulted in an overall survival of 70%, with an average follow-up of 3.5 years. Survival was highest in primary temporal bone lesions, and lowest in paranasal sinus lesions. Unresectable lesions were not cured by other modalities. This study, therefore, continued to support the crucial role of wide surgical resection in the treatment of head and neck chondrosarcoma, but conservative resection, when needed to preserve important structures, has resulted in long-term survival.
Zollinger-Ellison syndrome. Relation to Helicobacter pylori-associated chronic gastritis and gastric acid secretion. Since Helicobacter pylori infects the gastric mucosa in most patients with chronic duodenal ulcer, infection with this organism has been implicated in the pathogenesis of this common disease. We postulated that if H. pylori is pathogenic in the usual type of duodenal ulcer, it should be less common when duodenal ulcer has another, specific etiology, such as Zollinger-Ellison syndrome. Gastric mucosa was compared from 18 patients with proven Zollinger-Ellison syndrome (17 of whom had had duodenal ulcer disease) and 18 controls with chronic duodenal ulcer without such a diagnosis. All subjects, who were matched for age and sex, had undergone elective gastric resections. Gastric tissues were stained by hematoxylin-eosin and Giemsa and were reviewed by an experienced pathologist who was unaware of the diagnosis. The frequency of H. pylori in patients with Zollinger-Ellison syndrome (8/18) was lower than in controls with duodenal ulcer (16/18; P less than 0.02). Moreover, chronic antral gastritis scores were higher in patients with duodenal ulcer (P less than 0.01). In Zollinger-Ellison syndrome, peak acid output was lower in patients positive (median 22 meq/30 min) compared to those negative for H. pylori (median 32 meq/30 min; P less than 0.02) but serum gastrin was correspondingly lower in patients positive for H. pylori (P less than 0.05). H. pylori infection appears to be more frequent when duodenal ulceration is not associated with another etiology, such as acid hypersecretion in Zollinger-Ellison syndrome. H. pylori infection in Zollinger-Ellison syndrome may also be associated with decreased gastric acid secretion.
cDNA cloning and sequencing of human fibrillarin, a conserved nucleolar protein recognized by autoimmune antisera. We have isolated a 1.1-kilobase cDNA clone that encodes human fibrillarin by screening a hepatoma library in parallel with DNA probes derived from the fibrillarin genes of Saccharomyces cerevisiae (NOP1) and Xenopus laevis. RNA blot analysis indicates that the corresponding mRNA is approximately 1300 nucleotides in length. Human fibrillarin expressed in vitro migrates on SDS gels as a 36-kDa protein that is specifically immunoprecipitated by antisera from humans with scleroderma autoimmune disease. Human fibrillarin contains an amino-terminal repetitive domain approximately 75-80 amino acids in length that is rich in glycine and arginine residues and is similar to amino-terminal domains in the yeast and Xenopus fibrillarins. The occurrence of a putative RNA-binding domain and an RNP consensus sequence within the protein is consistent with the association of fibrillarin with small nucleolar RNAs. Protein sequence alignments show that 67% of amino acids from human fibrillarin are identical to those in yeast fibrillarin and that 81% are identical to those in Xenopus fibrillarin. This identity suggests the evolutionary conservation of an important function early in the pathway for ribosome biosynthesis.
Feasibility of intraoperative cytodiagnosis of lung cancer. Of 354 thoracotomies, 114 cases involved intraoperative cytopathologic evaluation. The study included 86 men and 28 women, and 184 specimens were examined. Smears were taken from the lung lesion or lymph node and the chest wall or bronchial stump by imprint or needle aspiration. Intraoperative evaluations were compared with histologic findings. In 85 cases not diagnosed as malignant preoperatively, malignancy was confirmed in 97.6 percent of cases and histologic type in 71.8 percent. In the 28 cases diagnosed as malignant preoperatively, there was only one false-negative. The most important finding during thoracotomy is whether a lesion is malignant or not. The time required to obtain a pathologic diagnosis also is important. We are able to obtain the results of a cytologic diagnosis within 10 min. Cytologic diagnosis of malignancy during thoractomy may be a feasible and convenient method of diagnosis, especially where malignancy is suspected.
Follicular thyroid cancer treated at the Mayo Clinic, 1946 through 1970: initial manifestations, pathologic findings, therapy, and outcome We retrospectively analyzed the outcome of all patients who received their primary treatment for follicular thyroid cancer at the Mayo Clinic between 1946 and 1970. The diagnosis was confirmed by reexamination of preserved tissue specimens. The 57 female and 43 male patients (mean age, 53 years) underwent follow-up for a maximum of 32 years (mean, 17.4 years). All patients were treated surgically, and total removal of primary tumor was thought to have been accomplished in all but three. Only 2 of the 88 patients without distant metastatic lesions at the time of initial diagnosis underwent ablation of the thyroid remnant. At the conclusion of the study, 52 patients had died, thyroid cancer being the cause of death in 19. On the basis of univariate survival analysis, age more than 50 years, tumor size that exceeded 3.9 cm, higher tumor grade, presence of marked vascular invasion, adjacent tissue invasion, and distant metastatic involvement at the time of initial diagnosis were associated with increased cancer mortality. Multivariate analysis (by Cox proportional hazards model), however, identified only age greater than 50 years, marked vascular invasion, and metastatic disease at the time of diagnosis to be independent predictors of follicular thyroid cancer-related mortality. Patients with two or more of these predictors were classified as being high risk. These patients had 5- and 20-year survival rates of 47% and 8%, respectively; the corresponding survival data for the low-risk group were 99% at 5 years and 86% at 20 years. The identification of these risk groups may facilitate a more rational approach to treatment of follicular thyroid cancer.
Left ventricular diastolic dysfunction presenting as ascites: the importance of clinically assessing central venous pressure. A 66-year-old man without history of heart disease or symptoms of left ventricular (LV) failure was admitted with transudative ascites. Echocardiography showed no valvular or pericardial disease and normal LV function. Gated pool scintigraphy confirmed normal LV systolic function but demonstrated severe right ventricular systolic dysfunction. Catheterization revealed left ventricular diastolic dysfunction as the cause of right-sided failure. The clinician evaluating transudative ascites cannot exclude LV failure on the basis of noninvasive assessment of systolic function alone. Appreciation of an elevated central venous pressure remains the most important evidence of a cardiac source of ascites.
Disseminated Pneumocystis carinii infection with hepatic involvement in a patient with the acquired immune deficiency syndrome. Extrapulmonary infection with Pneumocystis carinii (P. carinii) in AIDS patients is uncommon, and is often described only at postmortem examination. Although most antemortem cases involve spread to the bone marrow or spleen, P. carinii involvement of other organs has only recently been described. Despite the frequency of liver enzyme abnormalities in AIDS patients with a history of P. carinii pneumonia, P. carinii has been observed only rarely in the liver. We present a well-documented case of P. carinii involving the liver in an AIDS patient with P. carinii pneumonia and progressive liver enzyme abnormalities. We suggest that P. carinii infection should be considered in the differential diagnosis of AIDS-related liver disease.
Effects of discontinuation of phenytoin, carbamazepine, and valproate on concomitant antiepileptic medication. We report a prospective, controlled study of the effects of the reduction and discontinuation of phenytoin (PHT) (22 patients), carbamazepine (CBZ) (23 patients), and valproate (VPA) (25 patients) with concomitant antiepileptic drugs (AEDs). The principal changes in the serum concentrations of concomitant AEDs were (a) phenobarbital (PB) concentrations decreased by a mean of 30% on discontinuation of PHT; (b) total CBZ concentrations increased by a mean of 48% and free CBZ concentrations increased by a mean of 30% on discontinuation of PHT, with no change in CBZ-10, 11-epoxide (CBZ-E) concentrations; (c) VPA concentrations increased by a mean of 19% on discontinuation of PHT; (d) VPA concentrations increased by a mean of 42% on discontinuation of CBZ; (e) ethosuximide (ESM) concentrations increased by a mean of 48% on discontinuation of CBZ; (f) PHT concentrations decreased by a mean of 26% on discontinuation of CBZ; (g) PHT free fraction decreased from a mean of 0.11 to 0.07 on discontinuation of VPA; and (h) the mean concentrations of total and free CBZ increased by a mean of 10 and 16%, respectively, on VPA discontinuation, with a concomitant mean 24% decrease in total CBZ-E and a 22% decrease in free CBZ-E. Apart from the decrease in PB concentrations on PHT discontinuation, all significant changes had occurred by 1 week after the end of AED discontinuation. The implication for clinical practice is that a serum AED concentration at this time reflects the new steady state. Free concentrations did not add any clinically useful information to that gained from analysis of total serum concentrations.
Reduction of post-traumatic swelling and compartment pressure by impulse compression of the foot. Following the discovery of a powerful venous pump in the foot that is activated by weight-bearing independently of muscular action, a pneumatic impulse device was developed to actuate this pump artificially. In a multicentre international trial the device was shown to reduce post-traumatic and postoperative swelling; pain also was alleviated. Evidence is also presented that dangerously high compartment pressures may be reduced to acceptable levels and fasciotomy avoided. We present an explanation of the clinical effects of activation of the venous footpump, based on recent improved understanding of the physiology of the microcirculation. The hyperaemic response that follows the liberation of endothelial-derived relaxing factor (EDRF) by sudden changes of pressure after weight-bearing or impulse compression is particularly important.
Cutaneous melanoma and bilateral retinoblastoma. We report the case of an otherwise healthy 37-year-old man who had had bilateral enucleation during early childhood for bilateral retinoblastomas, in addition to two cutaneous melanomas (the first appearing at age 27 years). He also had dysplastic melanocytic nevi and a history of cutaneous melanoma in his mother. Retinoblastoma may aggregate in families and is associated with DNA abnormalities of chromosome 13. Recent reports have emphasized the appearance of second malignancies in retinoblastoma survivors. The second malignancies include osteosarcoma, soft tissue sarcoma, and cutaneous melanoma. Cutaneous melanoma also may aggregate in families, usually in the setting of dysplastic melanocytic nevi. The features of this case and of similar reported cases suggest that there may be a greater than expected association between retinoblastoma and cutaneous melanoma.
Expression of pancreatic secretory trypsin inhibitor gene in human colorectal tumor. Expression of pancreatic secretory trypsin inhibitor (PSTI) gene was examined by Northern blotting analyses in 31 human colorectal tumors that included two benign adenomas and 26 adenocarcinomas. Among the total of 28 cases which proved to be adequate for mRNA analyses, all but one showed the expression of PSTI at various levels. In contrast, PSTI expression was not detected in two malignant lymphomas of the rectum. The level of PSTI expression was not correlated with the patient's age, sex, tumor location or size, stage of differentiation, lymph node metastasis, or progression stage. Some colorectal adenocarcinomas were also shown to express genes that can hybridize with human trypsinogen cDNA probe. It looks as though in these tumors, a protease(s) and its inhibitor are produced simultaneously as part of a cellular self-defense mechanism.
Spontaneous sump syndrome: Successful treatment by duodenoscopic sphincterotomy. "Sump syndrome" is a rare complication of side-to-side choledochoenterostomy operations which develops in the distal, nonfunctioning limb of the common bile duct where lithogenic bile, gastrointestinal contents, and debris accumulate. We report here a patient who developed spontaneous sump syndrome as a result of the formation of choledochoduodenal fistula, and who presented with multiple pyogenic liver abscesses. The patient's symptoms and liver abscesses resolved completely after treatment by endoscopic sphincterotomy and antibiotics. This case demonstrates that sump syndrome may occur spontaneously, that it can be a cause for pyogenic liver abscess formation, and that it may be treated effectively by endoscopic sphincterotomy.
A population-based study of functional status and social support networks of elderly patients newly diagnosed with cancer. We assessed the functional status and social support networks of 799 men and women aged 65 years or older newly diagnosed with cancer and living in six New Mexico counties. Functional limitations included depending on others for transportation (33%) and mental incompetence or poor recent memory (42%). The percentage of patients with functional limitation increased sharply with increasing age. In a substantial number of patients there was also evidence for poor social support networks; 26.5% of subjects lived alone and 38.9% had no children living in the vicinity. In a multiple logistic regression analysis, the predictors of having a poor social support network included non-Hispanic white ethnicity, advanced age, low income, and being a recent migrant to the area. Subjects with functional limitations were more likely to have poor social support networks than subjects without such limitations. The deleterious combination of impaired functional status and a limited social support network may explain why elderly cancer patients are at increased risk for not receiving appropriate therapy. Given the potential complexities involving the evaluation and appropriate treatment of cancer, care must be taken to adequately assess functional status and support mechanisms of older patients, and to provide adequate support to ensure compliance with treatment.
Effect of preconditioning ischemia on reperfusion arrhythmias after coronary artery occlusion and reperfusion in the rat. Severe arrhythmias occur predictably on reperfusion after 5 minutes of coronary occlusion in the rat. There is little data available on whether ischemic preconditioning (PC) of hearts can reduce the incidence of such arrhythmias. The effect of PC (three cycles of 2 minutes of coronary occlusion and 5 minutes of reperfusion) on development of arrhythmias after a subsequent 5-minute coronary artery occlusion and reperfusion was studied. Rats (n = 16 each group) underwent 5-minute occlusion and reperfusion alone or preceded by PC; arrhythmias were monitored during ischemia and for 10 minutes of reperfusion, and biopsies were taken for creatine phosphate and adenosine triphosphate in ischemic and nonischemic zones of the left ventricle. PC reduced the incidence of ventricular tachycardia (VT) during occlusion (81% control versus 13% PC, p less than 0.001). On subsequent reperfusion, ventricular fibrillation (VF) developed in zero PC animals versus 13 (81%) of controls (p less than 0.001), and irreversible VF in zero of PC versus seven (44%) of controls (p = 0.007). VT occurred in four (25%) of PC versus all (100%) of controls (p less than 0.001). PC reduced mean duration of VT plus VF from 320 +/- 54 to 5 +/- 1 seconds (p less than 0.001) and delayed arrhythmia onset from 8 +/- 2 to 85 +/- 35 seconds after reperfusion. There was no difference in creatine phosphate levels in the ischemic zone at the end of reperfusion in PC animals compared with controls without irreversible VF (16.2 +/- 4.1 versus 15.5 +/- 3.9 nmol/mg protein, p = NS).
Second cancer after radiation therapy for cancer of the uterine cervix. Radiation-induced cancers after radiation therapy for cancer of the uterine cervix were investigated on 11,855 patients including 5725 patients treated with radiation therapy alone, 1969 postoperative radiation therapy and 4161 surgery alone. The observed-to-expected ratios of the second primary cancer was 0.933 for the patients with radiation therapy alone and 1.074 for the patients with postoperative radiation therapy, respectively. No significant increase was observed in the risk of second primary cancers when all sites were combined. However, assessing on site by site basis, significant excess was noted for the rectum cancer, leukemia, and bladder cancer for the radiation therapy group but not for the surgery group. A significant excess of lung cancer was observed in both radiation therapy and surgery groups, which was attributed to some other causative factors. Radiation-induced cancers were suggested to develop apparently in organs involved in the irradiated field.