123rc/medical_text huggingface dataset:
Late results of the left subcostal approach for automatic implantable cardioverter defibrillator implantation. A left subcostal surgical approach was used to implant an automatic implantable cardioverter defibrillator (AICD) in 48 patients with a history of nonfatal cardiac arrest or documented ventricular tachycardia/fibrillation. Electrophysiologic studies before surgery yielded induction of monomorphic or polymorphic ventricular tachycardia in 40 patients, whereas 8 were noninducible. Mean (+/- standard deviation) age was 58 +/- 12 years. Mean ejection fraction was 33 +/- 16%. Thirty patients (63%) had documented coronary artery disease; 14 patients (29%) had previous coronary bypass surgery. The mean intraoperative defibrillation threshold was 13.8 +/- 6.6 J. In 6 patients, an adjunctive right minithoracotomy was used to position 1 patch over the right atrium and thus optimize the defibrillation threshold. Patients with prior exposure to amiodarone and previous coronary bypass surgery had higher defibrillation thresholds at implantation. Two perioperative deaths occurred. There were no infections. Long-term follow-up yielded a 1- and 5-year survival of 0.88 and 0.58, respectively, and a freedom from sudden cardiac death of 1.0 and 0.97, respectively. The nonthoracotomy, left subcostal surgical approach is safe and effective, provides adequate defibrillation thresholds in most patients, and yields long-term survival comparable to other implantation techniques.
Mechanism of stroke in patients taking aspirin. During a 1-year period, we prospectively studied the mechanism and severity of stroke in 47 patients sustaining a cerebral infarction while taking aspirin. The mechanism of stroke was undetermined in 12 patients (26%). In the remaining 35 patients, we identified 39 potential mechanisms: large-artery atherosclerosis (19 patients, 40%), cardioembolism (15 patients, 32%), and small-vessel occlusive disease (5 patients, 11%). Of 11 patients with carotid atherosclerosis and stroke, 9 (82%) had greater than 90% carotid stenosis or occlusion; of 12 patients with stroke of undetermined mechanism, 10 (83%) had previous stroke, of which 8 were also of undetermined mechanisms. Disability after stroke was moderate or severe in 27 patients (57%). These data suggest that (1) stroke in patients taking aspirin has a variety of etiologies and frequently causes moderate or severe disability; (2) patients with carotid disease failing aspirin often have high-grade carotid stenosis or occlusion; (3) stroke of undetermined mechanism may recur more frequently than other stroke subtypes in patients taking aspirin.
Human catechol-O-methyltransferase: cloning and expression of the membrane-associated form. A cDNA clone for human catechol-O-methyltransferase (hCOMT; S-adenosyl-L-methionine:catechol O-methyltransferase; EC 2.1.1.6) was isolated from a human hepatoma cell line (Hep G2) cDNA library by hybridization screening with a porcine cDNA probe. The cDNA clone was sequenced and found to have an insert of 1226 nucleotides. The deduced primary structure of hCOMT is composed of 271 amino acid residues with the predicted molecular mass of 30 kDa. At its N terminus it has a hydrophobic segment of 21 amino acid residues that may be responsible for insertion of hCOMT into the endoplasmic reticulum membrane. The primary structure of hCOMT exhibits high homology to the porcine partial cDNA sequence (93%). The deduced amino acid sequence contains two tryptic peptide sequences (T-22, T-33) found in porcine liver catechol-O-methyltransferase (COMT). The coding region of hCOMT cDNA was placed under the control of the cytomegalovirus promoter to transfect human kidney 293 cells. The endogenous COMT activity, which was approximately 9.98 units per mg of protein in the untransfected cells, increased to 206 units per mg of protein upon transfection with a plasmid containing the COMT cDNA. The COMT activity of recombinant protein was inhibited competitively (IC50 = 700 nM) by the selective COMT inhibitor Ro 40-7592. An anti-COMT monoclonal antibody recognized, on immunoblots, a major polypeptide with apparent molecular mass of 29 kDa, in reasonable agreement with the predicted molecular mass. The recombinant hCOMT was shown by immunoblot analysis to be mainly associated with the membrane fraction. RNA blot analysis revealed one COMT mRNA transcript of 1.4 kilobases in Hep G2 poly(A)+ RNA.
Structure, expression and function of a schwannoma-derived growth factor. During the development of the nervous system, cells require growth factors that regulate their division and survival. To identify new growth factors, serum-free growth-conditioned media from many clonal cell lines were screened for the presence of mitogens for central nervous system glial cells. A cell line secreting a potent glial mitogen was established from a tumour (or 'schwannoma') derived from the sheath of the sciatic nerve. The cells of the tumour, named JS1 cells, were adapted to clonal culture and identified as Schwann cells. Schwann cells secrete an autocrine mitogen and human schwannoma extracts have mitogenic activity on glial cells. Until now, neither mitogen has been purified. Here we report the purification and characterization of a mitogenic molecule, designated schwannoma-derived growth factor (SDGF), from the growth-conditioned medium of the JS1 Schwann cell line. SDGF belongs to the epidermal growth factor family, and is an autocrine growth factor as well as a mitogen for astrocytes, Schwann cells and fibroblasts.
Raynaud's syndrome. Using a range of therapies to help patients. Raynaud's syndrome is a common medical problem. Approach to diagnosis must involve a search for underlying causes. Treatment includes avoidance of precipitating factors, biofeedback, and possibly pharmacologic therapy, after careful consideration of risks.
Factors affecting recurrence in lumpectomy without irradiation for breast cancer. Between 1980 and 1988, 122 women with operable invasive breast cancers underwent wide excision and axillary dissection without subsequent irradiation. During the follow-up period of 1 to 8 years (median, 4 years), recurrences were observed in 23 patients (19%), 22 occurring in the breast and one in the axilla. This is a significant rate of recurrence and supports the need for breast irradiation after conservative surgery. The incidence of recurrence in the breast did not appear to be related to the presence or absence of axillary nodal metastasis. No recurrences were noted in 20 patients whose primary tumors were smaller than 1 cm. The incidence of recurrence was directly correlated to the increasing size of the tumor, but it also appeared to decrease with advancing age. In 31 patients over 70 years of age, only one (3%) recurrence was observed. If these early findings are confirmed, it is likely that patients with tumors smaller than 1 cm or patients over 70 years of age may be spared breast irradiation after wide excision.
Surgical management of bile duct stones. The biliary surgeon in the 1990s must be familiar with all of the available techniques for the treatment of bile duct stones. Experience and judgment are important in the successful management of the individual patient with intrahepatic or extrahepatic stones. Knowledge of the nonsurgical methods of stone removal is important in the decision-making process. However, the biliary surgeon must resist the temptation to do less than a thorough removal of all stones at the operation lest the patient be subjected to additional procedures, which carry their own risks of morbidity and death. The goal should be to clear the stones from the biliary system with the fewest procedures offering the lowest morbidity and mortality risks to the patient.
Nosocomial infections due to Xanthomonas maltophilia (Pseudomonas maltophilia) in patients with cancer. From December 1985 to May 1986, Xanthomonas maltophilia (formerly known as Pseudomonas maltophilia) was isolated at an increased rate at our institution; 52 isolates of X. maltophilia were obtained in cultures of clinical specimens from 38 patients during that time. The records of 35 of these patients form the basis of this study. Twelve (71%) of the 17 infected and nine (50%) of the 18 colonized patients had received or were receiving antimicrobial therapy. Eleven of 17 patients (three of seven with septicemia, three of five with pneumonia, three with urinary tract infection, and two with wound infection) responded to antimicrobial therapy. Microbiologic studies of the potential environmental sources revealed growth of X. maltophilia in two water faucets and in one water sample from the medical intensive care unit. X. maltophilia is emerging as an important nosocomial pathogen in immunocompromised patients, especially those receiving broad-spectrum antimicrobial therapy.
Use of recombinant human erythropoietin (r-HuEPO) in a Jehovah's Witness refusing transfusion of blood products: case report. Recombinant human erythropoietin (r-HuEPO) administration to a Jehovah's witness refusing blood transfusions increased her nadir packed cell volume from 13% to 37% and reticulocyte count from 2% to 17.7%. R-HuEPO may provide an alternative safe and effective therapy in life-threatening anemia when blood transfusions are unacceptable to the patient.
Platelet aggregation is not necessary for occurrence of Raynaud's phenomenon: a clinical history and laboratory results. "Raynaud's phenomenon (R.P.) is characterized by a spastic vasoconstriction of hand and/or feet extremities leading to painful ischemic attacks. In the pathogeny of this syndrome the role of a platelet hyperactivation was evidenced. Nevertheless, the responsibility of platelet aggregation remains controversial. We report here the case of a patient presenting with a Glanzmann thrombasthenia defined by the complete lack of platelet aggregation, and showing a typical RP which was confirmed by the measurement of hand temperature and the decrease of digital and hand blood flow. Thus, the description of this case shows that platelet aggregation by itself is not necessary for the occurrence of RP, and encourages for therapeutic purposes the development of vasodilatators rather than platelet antiaggregants agents.".
Lidocaine local anesthesia for arthroscopic knee surgery. Forty-five patients were evaluated during knee arthroscopy performed using local anesthesia produced by lidocaine with epinephrine to determine the dose-response relationship for operative analgesia. Serum lidocaine concentrations were also measured. Patients were randomized prospectively to receive 20 mL of 0.5%, 1.0%, or 1.5% lidocaine with epinephrine intraarticularly. Intraoperative discomfort was measured by verbal response on an 11-point linear pain scale. Pain scores were significantly higher in patients receiving 0.5% lidocaine during the first 45 min of surgery (P = 0.03). After 45 min, pain scores continued to be higher in the 0.5% lidocaine group than in the 1.0% or 1.5% groups, but the differences were not statistically significant. Ninety-four percent of patients in the 1.5% lidocaine group were willing to repeat this anesthetic technique for surgery compared with 83% of those in the 1.0% lidocaine group and 75% of those in the 0.5% lidocaine group (P greater than 0.05). The duration of postoperative analgesia was similar in all groups. Serum lidocaine concentrations before and 15, 30, 60, and 120 min after instillation of lidocaine were highest in the 1.5% lidocaine group with a peak concentration of 278 ng/mL. No patient had symptoms of lidocaine toxicity. We recommend that lidocaine concentrations of 1.0% or 1.5% be used when 20 mL is instilled intraarticularly for knee arthroscopy based on patient comfort and absence of lidocaine toxicity.
Desmopressin for diabetes insipidus, hemostatic disorders and enuresis. Arginine vasopressin preparations have been used in the treatment of diabetes insipidus for many years. Compared with older antidiuretic agents, the synthetic analog desmopressin is more potent, longer acting and easier to use. It is available for intravenous, subcutaneous and intranasal administration. Desmopressin may be useful in the treatment of hemostatic disorders such as von Willebrand's disease and hemophilia A. It has also been used for nocturnal enuresis. The vasopressor effects of arginine vasopressin preparations have been exploited for use as a temporizing measure in controlling acute gastrointestinal bleeding. Side effects such as hyponatremia and water intoxication are uncommon when these drugs are used with proper precautions.
A rheolytic system for percutaneous coronary and peripheral plaque removal. A method for plaque dissolution has been identified that percutaneously delivers a pulsatile high-velocity stream of saline to the site of an atheromatous lesion within a coronary or peripheral artery. In vitro evaluation and in vivo canine and porcine testing were performed using this 'rheolytic' system to determine its feasibility in ablating calcified plaque and soft thrombotic tissue. A prototype rheolytic guidewire capable of providing 30,000 psi of internal pressure was designed to fit within the guidewire lumen of a standard percutaneous transluminal coronary angioplasty catheter. An additional over-the-wire rheolytic catheter was fabricated to follow a standard .014-inch guidewire. The rheolytic devices were tested in vitro with simulated atheromatous and thrombotic lesions to evaluate the size and quantity of the particulate effluent. The particulate was then sterilized, mixed with saline, and introduced percutaneously into the animal kidney and heart for evaluation. The in vitro studies demonstrated that the rheolytic catheter and guidewire were able to follow both a coronary and femoral arterial model and successfully ablate the simulated lesions. The particle size for osseous, muscular, and cartilagenous tissue ranged from 2 to 6 micrometers; for fresh human plaque the particles ranged from 2 to 15 micrometers. Injection of cartilagenous and plaque particles into the animal model caused very slight regions of necrosis but no clinical sequelae. Applications of the rheolytic devices to the animal femoral artery demonstrated that both devices could ablate and cross calified or soft thrombosed lesions without damage to the vessel wall; the rheolytic catheter provided a debulking of the plaque.
A hospital-based study of acute viral infections of the respiratory tract in Thai children, with emphasis on laboratory diagnosis. The hospital-based study described here examined the viruses found in 738 children less than 5 years old who presented at Ramathibodi Hospital, Bangkok, Thailand, from January 1986 to December 1987 with acute respiratory tract infections. Three methods for detection of viral infection are compared: direct examination of epithelial cells of the respiratory tract with the use of fluorescent antibody staining, isolation of virus, and measurement of antibody in acute- and convalescent-phase sera. Viral infections were found in 44.7% of the study population. Diagnosis by the examination of epithelial cells with the fluorescent antibody staining procedure was found to have several deficiencies; however, this technique was the most sensitive for diagnosis of infection due to respiratory syncytial virus. Isolation of virus was the best method for identification of adenoviruses, parainfluenza 1 and 3 viruses, and influenza B virus. Problems associated with serodiagnosis included failure to obtain specimens of convalescent-phase blood in 24.5% of cases and insensitivity of serodiagnosis for young children except for the identification of antibody to influenza A virus. The combination of all three tests yielded the best rate of detection of virus.
Stress management in the treatment of mild primary hypertension. The use of simple relaxation-based stress management procedures in the treatment of mild primary hypertension has been the subject of extensive study. Stress management appears to lead to reliably greater reductions in pressure than a variety of control procedures. The mechanisms underlying these effects are obscure, and research has not identified which patients will benefit most from treatment. Preliminary data suggest that stress management may reduce the risk of coronary heart disease, but much research must be done if this is to be confirmed. It is suggested that such research should take into account the possibility that stress management may have beneficial effects on more than just hypertension-related aspects of the cardiovascular disease process.
Cardiovascular risk reduction: the role of antihypertensive treatment. The effects of antihypertensive drugs on mortality from stroke, coronary artery disease (CAD), and nonvascular causes have been studied in 14 trials involving more than 37,000 patients. In the treated patients, blood pressure was 5 to 6 mm Hg lower than that in placebo-treated patients, and whereas mortality from stroke was reduced by 42%, CAD mortality was reduced by only 14%. A major reason for this lack of effect on CAD mortality is apparently the adverse effects of the primary drugs used in these trials (diuretics and beta blockers) on glucose tolerance, lipid levels, and insulin resistance. The angiotensin-converting enzyme inhibitors favorably influence many CAD risk factors, and their use can be expected to reduce CAD mortality in patients treated for hypertension.
The fastigial pressor response. Case report. A distinct vasomotor and cardioregulatory response first identified experimentally was elicited intraoperatively in a 6-year-old girl by local mechanical stimulation in the vicinity of the fastigial nucleus of the cerebellum. These findings are discussed in the light of current experimental knowledge of the anatomy and physiology of the fastigial pressor response.
Use of cytoplasmic 5'nucleotidase for differentiating malignant from benign monoclonal gammopathies. Bone marrow smears from 15 patients with multiple myeloma, 15 patients with monoclonal gammopathy of undetermined significance (MGUS), and 15 control subjects were examined for the presence of cytoplasmic 5'nucleotidase (c5NT) in plasma cells. Plasma cell positivity for c5NT (mean and 95% confidence interval) in patients with multiple myeloma numbered 46.4% (38.0-54.8%), in those with MGUS it was 15.3% (11.1-19.6%), and in control subjects it was 1.2% (0.3-2.1%). These findings indicate that c5NT can be used to differentiate benign from malignant monoclonal gammopathies.
Stereotactic investigation of limbic epilepsy using a multimodal image analysis system. Technical note. A methodology has been developed for stereotactic investigation of limbic epilepsy using an image-analysis system that simultaneously displays different structural and functional images of the brain. The validity and accuracy of this system were established with phantom studies. Surgical planning and electrode implantation are guided by stereotactic magnetic resonance imaging, digital subtraction angiography, and position emission tomography. This methodology provides the spatiotemporal relationship of cerebral structure and function necessary to identify seizure onset and propagation in human limbic system epilepsy.
Comparative investigation of c-erbB2/neu expression in head and neck tumors and mammary cancer. Normal tissues, primary tumors, and metastases of mammary and salivary glands and oral/laryngeal mucosa have been analyzed with Northern-blots employing 32P-labeled RNA probes for the expression of the neu oncogene. Neu oncogene expression of a mRNA species of 4.6 kilobases was found in all normal salivary (five) and mammary glands (four) as well as in two normal or inflamed samples of tongue mucosa. This expression was regarded as baseline activity of the neu gene for the respective tissues and was used as standard for the evaluation of benign and malignant tumors. None of 14 squamous cell carcinomas of the oral and laryngeal mucosa showed enhanced neu transcription level. Five fibroadenomas, one benign variant of phylloid tumor, one carcinosarcoma, and one of two proliferative fibrocystic diseases of the breast showed lacking or normal baseline expression of the neu oncogene, as did one monomorphous cystadenolymphoma of the parotid gland. In contrast, four parotid pleomorphic adenomas and one salivary gland adenocarcinoma showed enhanced neu expression. For mammary adenocarcinomas, increased neu oncogene expression concerned ten of 34 cases--all being variants of ductal carcinomas--and all metastases analyzed (six) deriving from three primaries. One adenoid cystic carcinoma also showed enhanced neu expression. Neu overexpression may reflect accidents of genomic reconstitutional events occurring regularly within the differentiation pathway of epithelial/myoepithelial cells. This assumption was supported by further immunohistochemical analysis which showed stainings of myoepithelial and myoepithelia-like cell populations in tumors, especially pleomorphic adenomas and adjacent normal-looking tissues.
Intrahepatic cholestasis of pregnancy and acute fatty liver of pregnancy. An unusual but favorable association? During the 26th week of a first pregnancy, a 25-year-old woman presented with pruritus suggesting an intrahepatic cholestasis of pregnancy. The pruritus, however, persisted despite the premature delivery of a normal newborn at the 35th week. Moreover, aspartate aminotransferase activity increased, reaching a maximum of 38 times normal level on the 17th day after the delivery. Thus, an acute fatty liver of pregnancy was suspected and confirmed by liver biopsy. This patient appeared to have both intrahepatic cholestasis of pregnancy and acute fatty liver of pregnancy, an association not previously reported. It is suggested that intrahepatic cholestasis of pregnancy caused premature delivery, which in turn may have prevented the onset of severe maternal and fetal complications caused by acute fatty liver of pregnancy.
The electrodiagnostic findings in polyneuropathies associated with IgM monoclonal gammopathies. Electrodiagnostic studies were analyzed in patients with neuropathy associated with IgM monoclonal proteins, 7 with anti-myelin associated glycoprotein reactivity (MAG) and 7 nonreactive to MAG. The findings were distinctly different in the two groups. The electrodiagnostic studies of all the MAG-reactive patients had demyelinating features with slowing of conduction and prolonged distal latencies while only one of the MAG-nonreactive patients had a demyelinating pattern. In fact, the MAG-nonreactive patients were a heterogeneous group, both electrodiagnostically and clinically. This study supports the concept that MAG-reactive polyneuropathy is demyelinating in type, and is caused by the activity of the IgM M-protein directed at an antigen in the myelin sheath.
Depression of serum melatonin in patients with primary breast cancer is not due to an increased peripheral metabolism. Serum melatonin and its main metabolic product 6-sulfatoxymelatonin were determined in 17 patients with breast cancer (BC) with either a fresh primary tumor (nine) or a secondary tumor (eight) as well as in four patients with untreated benign breast disease (controls). Circadian rhythms were detected in all groups with acrophases around 2 AM for melatonin and around 3 AM for 6-sulfatoxymelatonin. The nocturnal melatonin and 6-sulfatoxymelatonin concentrations were significantly depressed in the group of patients with primary breast cancer compared with controls (P less than 0.01, P less than 0.025). The circadian amplitudes of melatonin and 6-sulfatoxymelatonin were also depressed by 81% (P less than 0.01) and 63% (P less than 0.01). In contrast, patients with secondary BC had nocturnal melatonin and 6-sulfatoxymelatonin concentrations and amplitudes similar to controls. These results demonstrate that the depression of circulating melatonin in patients with primary BC is not due to an enhanced degradation to 6-sulfatoxymelatonin in the liver but must be due to a reduced activity of the pineal gland.