123rc/medical_text huggingface dataset:
Is adenosine 5'-triphosphate derangement or free-radical-mediated injury the major cause of ventricular dysfunction during reperfusion? Role of adenine nucleoside transport in myocardial reperfusion injury. The aim of this study was to determine the dual role of ATP as an energy substrate and as a major source of oxygen-derived free-radical-mediated reperfusion injury by using adenine nucleoside blocker, p-nitrobenzylthioinosine (NBMPR), and adenosine deaminase inhibitor, erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA). In a randomized study, 16 dogs were instrumented with minor-axis LTZ-piezoelectric crystals and intraventricular pressure transducers to monitor, off bypass, left ventricular performance by using a sensitive and load-independent index of contractility (slope of the stroke work-end-diastolic length relation). Hearts were subjected to 60 minutes of normothermic global ischemia and 120 minutes of reperfusion. Normal saline without (Group 1, n = 8) or with (Group 2, n = 8) NBMPR and EHNA was infused in three boluses into the cardiopulmonary bypass reservoir before ischemia and reperfusion. Transmural serial biopsies were obtained before and during ischemia and reperfusion and analyzed for myocardial adenine nucleotide pool intermediates by using high-performance liquid chromatography. In the control group, three hearts developed ischemic contracture and another three hearts exhibited cardiogenic shock during reperfusion. In the EHNA/NBMPR-treated group, left ventricular performance recovered within 30 minutes of reperfusion (p less than 0.05 vs. control). Myocardial ATP was depleted to 20% of normal in both groups by the end of ischemia (p less than 0.05). Intramyocardial adenosine in the EHNA/NBMPR-treated group was 12-fold greater (15.09 +/- 1.6 nmol/mg protein) than the control group at the end of the ischemic period (p less than 0.05). Inosine was about fourfold higher in the control group (19.07 +/- 1.50 nmol/mg protein) compared with the drug-treated group (p less than 0.05). During reperfusion, myocardial ATP levels increased to approximately 50% of normal in the EHNA/NBMPR group while remaining depressed (20% of normal) in the control group. Thus, despite the dramatic loss of myocardial ATP during ischemia, complete recovery of ventricular performance and significant repletion of ATP during reperfusion were observed when adenosine transport and deamination were modulated during ischemia and reperfusion. These results suggest that 1) the myocardium may have more ATP than is needed for basic cardiac functions and 2) washout of ATP diffusible catabolites is detrimental to ventricular performance during reperfusion. Specific blockade of nucleoside transport resulted in complete functional recovery despite low but critical ATP levels.(ABSTRACT TRUNCATED AT 400 WORDS).
Donor leukocyte transfusions for treatment of recurrent chronic myelogenous leukemia in marrow transplant patients. Three patients with hematologic relapse after bone marrow transplantation for chronic myelogenous leukemia were treated with interferon alpha and transfusion of viable donor buffy coat. All had complete hematologic and cytogenetic remission, which persisted 32 to 91 weeks after treatment. In two patients graft-versus-host disease developed and was treated by immunosuppression. These results are an example of adoptive immunotherapy without cytoreductive chemotherapy or radiotherapy in human chimeras.
Mechanisms of gallstone formation in women. Effects of exogenous estrogen (Premarin) and dietary cholesterol on hepatic lipid metabolism. Our aim was to define mechanisms whereby conjugated estrogens (Premarin, exogenous estrogen; Ayerst Laboratories, New York) increase the risk of developing cholesterol gallstones and to determine the role, if any, of dietary cholesterol. We studied gallbladder motor function, biliary lipid composition and secretion, cholesterol absorption, cholesterol synthesis and esterification by peripheral blood mononuclear cells, the clearance of chylomicron remnants, and bile acid kinetics in 29 anovulatory women. 13 were studied on both a low (443 +/- 119 mumol/d) and high (2,021 +/- 262 mumol/d) cholesterol diet. Premarin increased the lithogenic index of bile (P less than 0.05), increased biliary cholesterol secretion (P less than 0.005), lowered chenodeoxycholate (CDCA) pool (P less than 0.001) and synthesis (P less than 0.05), altered biliary bile acid composition [( CA + DCA]/CDCA increases, P less than 0.005), stimulated cholesterol esterification (P less than 0.03), and enhanced the clearance of chylomicron remnants (P = 0.07). Increases in dietary cholesterol stimulated the biliary secretion of cholesterol (P = 0.07), bile acid (P less than 0.05), phospholipid (P = 0.07), and as a result, did not alter lithogenic index. The reduction in CDCA pool and synthesis by Premarin was reversed by increasing dietary cholesterol. Off Premarin, only 24% of the increase in cholesterol entering the body in the diet was recovered as biliary cholesterol or newly synthesized bile acid. On Premarin, 68% of this increase in cholesterol was recovered as these biliary lipids. We conclude that Premarin increases biliary cholesterol by enhancing hepatic lipoprotein uptake and inhibiting bile acid synthesis. These actions of Premarin divert dietary cholesterol into bile.
Rural-urban differences in stage at diagnosis. Possible relationship to cancer screening. Stage at diagnosis was examined for various malignancies identifiable through screening to determine whether rural-urban differences exist in Georgia. Data were obtained from a population-based cancer registry which registers all incident cancers among residents of metropolitan Atlanta and ten neighboring rural counties. Black and white patients with a first primary invasive malignancy newly diagnosed between 1978 and 1985 were included in this study. Residents of the rural area were twice as likely to have unstaged cancers (18.3%) as were urban residents (9.6%). Among patients with known stage at diagnosis, rural patients tended to have more advanced disease than urban patients. The relative excess of nonlocalized malignancies in rural Georgia was 21% for whites and 37% for blacks. The rural excess of nonlocalized prostate cancer among blacks was especially pronounced. Differences in access to or utilization of early detection methods may contribute to the rural-urban differential in the extent of disease at diagnosis.
Effects of aging on the swallowing mechanism. Normal swallow involves a number of closely coordinated neuromuscular events. Investigators have identified some small temporal changes in the swallow of older adults as compared with young adults. Further research is needed to define completely the primary effects of aging on deglutition. Many medical conditions that commonly affect the elderly can cause dysphagia. These are discussed in terms of their effects on swallow physiology. Diagnosis and treatment of dysphagia in the elderly should be pursued as aggressively as in the younger adult.
Seizure disorders in Down syndrome. The prevalence, onset, and type of seizure disorders, as well as seizure control, were studied in a large cohort of 405 individuals with Down syndrome (age range, 6 months to 45 years). The evaluation of a questionnaire completed by the subjects' parents and of the patients' medical records indicated that 33 (8.1%) of 405 persons with Down syndrome had seizure disorder. With regard to the onset of seizures, a bimodal distribution was noted: 40% of patients began having seizures before the age of 1 year, and another 40% started with seizure activity in the third decade of life. In the younger age group, primarily infantile spasms and tonic-clonic seizures with myoclonus were observed, and the older patients often had partial simplex or partial complex seizures as well as tonic-clonic seizures.
Healing of a large nonossifying fibroma after grafting with bone matrix and marrow. A case report. Healing of a large tibial nonossifying fibroma in a 12-year-old girl occurred following excision, curettage, and filling of the bony defect with human demineralized bone matrix powder mixed with a small quantity of the patient's bone marrow. The use of this graft composite was successful in the treatment of the lesion and reduced the potential risk and morbidity associated with pediatric orthopedic surgical procedures with autogeneic iliac crest and other bone grafts.
Extrageniculate vision in hemianopic humans: saccade inhibition by signals in the blind field. The functional competence of extrageniculate visual pathways in hemianopic humans was demonstrated by showing that distractor signals in the blind half of the visual field could inhibit saccades toward targets in the intact visual field. This inhibitory effect of unseen distractors in patients occurred only when distractors were presented in the temporal half of the visual field, was specific to oculomotor responses, and did not occur in normal subjects. These results show that a peripheral visual signal activates retinotectal pathways to prime the oculomotor system and that these pathways can mediate orienting behavior in hemianopic humans.
Platelet-activating factor. A putative mediator in central nervous system injury? Platelet-activating factor (1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphorylcholine) is a potent lipid autacoid produced by many cell types. Platelet-activating factor is produced by cerebellar granule cells in culture and has been extracted from brain tissue. Multiple platelet-activating factor receptors have been demonstrated in brain tissue. Activation of platelet-activating factor receptors in transformed neuronal cell lines involved increases in intracellular calcium. Platelet-activating factor has potent actions on cerebral vessels and cerebral metabolism when administered in vivo, but may not have direct effects on brain microvessels. Excessive platelet-activating factor production in pathological states of the nervous system such as neurotrauma and stroke has been shown in only a few models (e.g., spinal cord ischemia and reperfusion or focal repercussion brain injury). In multiple studies using highly specific and potent platelet-activating factor antagonists, reversal or prevention of key consequences of brain injury such as hypoperfusion following ischemia, reperfusion and edema, inflammatory cell accumulation, neurologic/motor deficits, and neuronal salvage were demonstrated. This review provides and analyzes evidence in support of the role that platelet-activating factor might have in modulation of brain function and pathophysiological processes in brain ischemia and trauma.
Proximal esophageal pH-metry in patients with 'reflux laryngitis'. Fiberoptic laryngoscopic examinations were performed on 40 patients with gastroesophageal reflux disease, 25 of whom had persistent laryngeal symptoms (dysphonia, cough, globus sensation, frequent throat clearing, or sore throat) and 15 without laryngeal symptoms who served as disease controls. Ten patients with laryngeal symptoms but none of the controls had laryngoscopic findings consistent with reflux laryngitis. Dual-site ambulatory pH recordings were obtained with the pH electrodes spaced 15 cm apart and with the proximal sensor positioned just distal to the upper esophageal sphincter. Patients in the three groups (disease controls: group 1; patients with symptoms but without laryngoscopic findings: group 2; and patients with both laryngeal symptoms and findings: group 3) were comparable in terms of age, smoking habit, the presence of esophagitis, and distal esophageal acid exposure. Proximal esophageal acid exposure was, however, significantly increased in groups 2 and 3, and nocturnal proximal esophageal acidification occurred in over half of these patients but in none of the group 1 patients. We conclude that the subset of reflux patients who experience laryngeal symptoms show significantly more proximal esophageal acid exposure (especially nocturnally) and often have laryngoscopic findings of posterior laryngitis not observed in control reflux patients.
Intraoperative pleural lavage cytology in lung cancer patients. Cytology of intraoperative pleural lavage was examined in 164 lung cancer patients who underwent pulmonary resections. None of the patients had any pleural effusion or dissemination. Cytology was performed three times: (1) at thoracotomy, (2) immediately after resection, and (3) after washing the pleural cavity with 5,000 mL of physiological saline solution just before closure of the chest wall. Twenty-three patients (14%) had more than one positive cytological finding. The frequency of positive cytological findings was significantly correlated with pathological T classification, pleural status, and pathological stage. The positive lavage group had a significantly higher recurrence rate than the negative lavage group in patients with stage I or stage II cancer. Four patients in the positive lavage group (17.4%) had recurrence in pleura or pericardium whereas only 1 patient in the negative lavage group (0.7%) had a recurrence in pericardium. The positive cytological finding of pleural lavage has more important meaning as a prognostic factor in stage I and stage II and indicates a greater possibility of recurrence in pleura or pericardium, but further examinations to evaluate the viability of detected malignant cells are required so that the positive cytological findings of pleural lavage can be regarded as subclinical pleural dissemination.
Anton's syndrome in a patient with posttraumatic optic neuropathy and bifrontal contusions. We describe a patient who manifested Anton's syndrome after sustaining head trauma that resulted in optic nerve damage and bifrontal contusions. Denial of monocular blindness, generalized anosognosia, and confabulation were prominent neurobehavioral features. Anton's syndrome is most commonly encountered in patients with bilateral occipital cortex lesions. Patients previously described who demonstrated Anton's syndrome secondary to a peripheral lesion have had an associated delirium or profound dementia. Our case demonstrates that Anton's syndrome may occur in association with blindness from a peripheral lesion, even in the absence of a delirium or significant dementia. We suggest that the bifrontal dysfunction may have been a critical factor in the production of Anton's syndrome. Implications for the role of frontal lobe dysfunction in the genesis of anosognosia and confabulation are discussed.
Warm induction blood cardioplegia in the infant. A technique to avoid rapid cooling myocardial contracture. The use of profound hypothermia and total circulatory arrest for repair of heart defects in neonates usually involves a period of systemic and myocardial bypass cooling. Rapid cooling of muscle (skeletal, smooth, and myocardial) can result in contracture through elevation of cytosolic calcium levels. The increased myocardial tone caused by cooling might render the heart more vulnerable to a subsequent period of cardioplegic ischemic arrest. Infants may be more susceptible to contracture because their small body mass allows more rapid myocardial temperature change when prearrest bypass cooling is used. The influence of avoiding rapid myocardial cooling before induced cardioplegic arrest was analyzed in a group of infants weighing less than 6 kg at the time of open cardiac operation. Myocardial ischemic arrest by warm (37 degrees C) induction blood cardioplegia was used in 57 infants and compared with results in 440 infants treated with standard blood cardioplegia. Multivariate logistic regression analysis revealed that patient diagnosis, weight, and age at operation were significant risk factors for operative mortality. The use of warm induction blood cardioplegia had a strongly positive independent effect on survival (p = 0.0003) for any patient weight, age, or diagnostic group. We recommend the avoidance of rapid myocardial cooling on bypass in all patients before induction of cardioplegic ischemic arrest.
New approaches in the rehabilitation of the traumatic high level quadriplegic. The use of noninvasive alternatives to tracheostomy for ventilatory support have been described in the patient management of various neuromuscular disorders. The use of these techniques for patients with traumatic high level quadriplegia, however, is hampered by the resort to tracheostomy in the acute hospital setting. Twenty traumatic high level quadriplegic patients on intermittent positive pressure ventilation (IPPV) via tracheostomy with little or no ability for unassisted breathing were converted to noninvasive ventilatory support methods and had their tracheostomy sites closed. Four additional patients were ventilated by noninvasive methods without tracheostomy. These methods included the use of body ventilators and the noninvasive intermittent positive airway pressure alternatives of IPPV via the mouth, nose, or custom acrylic strapless oral-nasal interface (SONI). Overnight end-tidal pCO2 studies and monitoring of oxyhemoglobin saturation (SaO2) were used to adjust ventilator volumes and to document effective ventilation during sleep. No significant complications have resulted from the use of these methods over a period of 45 patient-years. Elimination of the tracheostomy permitted significant free time by glossopharyngeal breathing for four patients, two of whom had no measurable vital capacity. We conclude that noninvasive ventilatory support alternatives can be effective and deserve further study in this patient population.
Codeine plus paracetamol versus paracetamol in longer-term treatment of chronic pain due to osteoarthritis of the hip. A randomised, double-blind, multi-centre study. This randomized, double-blind, multi-centre study was undertaken to evaluate the efficacy and safety of treatment for 4 weeks with codeine plus paracetamol versus paracetamol in relieving chronic pain due to osteoarthritis of the hip. A total of 158 outclinic patients entered the study. Eighty-three patients (mean age 66 years) were treated with codeine 60 mg plus paracetamol 1 g 3 times daily, and 75 patients (mean age 67 years) with paracetamol 1 g 3 times daily. Ibuprofen 400 mg was prescribed as rescue medication. Due to an unexpected high rate of adverse drug reactions, the study was closed before the planned 400 patients had entered. Over weeks 1-4, 87%, 64%, 61% and 52% of patients in the codeine plus paracetamol group, and 38%, 31%, 22% and 29% of patients in the paracetamol group had one or more adverse drug reactions. Significantly more patients in the codeine plus paracetamol group had adverse drug reactions in each of the 4 weeks. Nausea, dizziness, vomiting and constipation were predominant adverse reactions in the codeine plus paracetamol group. During the first week of treatment, 30 patients (36%) in the codeine plus paracetamol group and 9 (12%) in the paracetamol group dropped out. As evaluated from patients completing the first week of treatment, the pain intensity during that week compared to their baseline pain was significantly lower in the codeine plus paracetamol group than in the paracetamol group. Moreover, during the first week the paracetamol group received rescue medicine significantly more frequently. In conclusion, when evaluated after 7 days of treatment, the daily addition of codeine 180 mg to paracetamol 3 g significantly reduced the intensity of chronic pain due to osteoarthritis of the hip joint. However, several adverse drug reactions, mainly of the gastrointestinal tract, and the larger number of patients withdrawing from treatment means that the addition of such doses of codeine cannot be recommended for longer-term treatment of chronic pain in elderly patients.
Generation of ammonia and mucosal lesion formation following hydrolysis of urea by urease in the rat stomach. We examined the morphological changes in gastric mucosa and the generation of ammonia after exposure of the rat stomach to urea in the presence of urease, in attempts to investigate a pathophysiological role of urea, urease, and ammonia system in gastric ulcer diseases. Exposure of the stomach for 20 min to 2 ml urea (0.025-0.2%) together with urease (100 IU) induced histological damages in a concentration-related manner. Either urea or urease alone did not induce any histological change in the mucosa. Instillation of urea into the stomach generated ammonia in the presence of urease; the amount of ammonia was increased depending on the concentration of urea, and was closely associated with the severity of histological damage. The exposure of the stomach to ammonia (NH4OH: 0.01-0.1%) also produced histological damages in the gastric mucosa in a concentration-related manner. The characteristics of injury induced by 0.5-1.0% ammonia were stasis of microcirculation, disruption of the surface epithelial cells, and necrosis of the mucosa. These results demonstrated that ammonia generated from the hydrolysis of urea by urease in the stomach causes damages in the gastric mucosa.
Recurrent renal cell carcinoma arising in Wilms' tumor. A 19-month-old black girl had a radical nephrectomy for a Wilms' tumor that contained areas of epithelium indistinguishable from renal cell carcinoma. She was treated with chemotherapy but subsequently had pulmonary metastases develop and massive abdominal recurrence. The recurrent tumor was histologically renal cell carcinoma with no identifiable Wilms' tumor elements. The child died with recurrent and metastatic tumor 13 months after nephrectomy. Pathologic, immunoperoxidase, and flow cytometric studies of this unusual case are presented.
Effects of common illnesses on infants' energy intakes from breast milk and other foods during longitudinal community-based studies in Huascar (Lima), Peru. To assess the effects of common infections on dietary intake, 131 Peruvian infants were observed longitudinally. Home surveillance for illness symptoms was completed thrice weekly, and food and breast-milk consumption was measured during 1615 full-day observations. Mean (+/- SD) energy intakes on symptom-free days were 557 +/- 128 kcal/d (92.4 +/- 26.5 kcal.kg-1.d-1) for infants aged less than 181 d and 638 +/- 193 kcal/d (77.7 +/- 25.7 kcal.kg-1.d-1) for infants aged greater than 180 d. Statistical models controlling for infant age, season of the year, and individual showed significant 5-6% decreases in total energy intake during diarrhea or fever. There were no changes with illness in the frequency of breast-feeding, total suckling time, or amount of breast-milk energy consumed. By contrast, energy intake from non-breast-milk sources decreased by 20-30% during diarrhea and fever, and the small decrements in total energy consumption during illness were explained entirely by reduced consumption of non-breast-milk foods.
Subnormal parasympathetic activity after cardiac transplantation. Heart period variability (standard deviation of 120 consecutive RR or PP intervals) was used to assess baseline parasympathetic activity in 18 patients with congestive heart failure before and after orthotopic cardiac transplantation, and was compared to that of 16 age-matched control subjects. Mean heart period variability (+/- standard error of the mean) was significantly greater (p less than 0.05) in control subjects (58 +/- 5 ms) than in the patients at any time before or after transplantation. Heart period variability of innervated recipient atria did not change significantly early (1 to 4 weeks) after transplantation (16 +/- 2 to 24 +/- 5 ms; p = 0.11), but increased significantly between weeks 15 and 37 after transplantation (30 +/- 5 ms, p less than 0.002 versus before transplantation). A stepwise regression model (R2 = 0.35; p = 0.01) showed that heart period variability was directly related to time after transplantation and inversely related to systolic arterial pressure after transplantation and degree of rejection. Heart period variability of the denervated donor atria did not change from early to late periods after transplantation, suggesting that vagal reinnervation of the donor heart had not occurred. These data indicate that baseline parasympathetic activity does not increase significantly during the first month after transplantation but increases significantly between months 3 and 6.