Melricflash/CW_MedAbstractsAlt huggingface dataset:
Hypertension with concomitant conditions: the changing role of beta-adrenoceptor blockade. Hypertension often is associated with concomitant conditions such as chronic obstructive lung disease, diabetes mellitus, ischemic heart disease, and peripheral vascular disease. Moreover, other cardiovascular risk factors, including dyslipidemias and abnormalities of glucose and insulin metabolism, are common in patients with hypertension. Conventional beta-blockers used for antihypertensive therapy can have adverse effects in patients with airway disease, diabetes, and peripheral vascular disease, and can exaggerate the other risk factors. Newer beta-blockers such as celiprolol, which have selective partial agonist activity expressed at beta 2-receptors, appear to avoid these problems. Celiprolol exhibits antianginal and antihypertensive efficacy without adversely effecting left ventricular systolic function or exercise performance. It also may cause regression of left ventricular hypertrophy. The stimulatory action of celiprolol on vascular beta 2-receptors enhances regional flow and may increase walking distance in patients with claudication. The reduction in renal vascular resistance demonstrated by this drug is associated with preservation of renal blood flow and function. Spirometric measurements of airway function are unchanged during celiprolol treatment. Similarly, there are no adverse effects on lipid or glucose concentrations. These new developments in beta-blocker pharmacology indicate that this class of agents could be used in patients with hypertension with concomitant diseases or risk factors other than high blood pressure. 

Category: cardiovascular diseases
Nausea, vomiting, and retching. Although nausea, vomiting, and retching have plagued mankind since antiquity, limited attention has been given to the three symptoms as separate entities. Although knowledge of symptom occurrence is essential to practice, nurses must focus on patients' response or distress to the occurrence of symptoms. The differentiation of symptom occurrence and symptom distress of nausea, vomiting, and retching is critical to the management and self-care demands of patients and the enhancement of their quality of life. Basic research on patterns of these individual symptoms and their components promises to provide a more progressive and fruitful approach to the patient response to these symptoms. 

Category: general pathological conditions
Blood conservation in cardiac surgery. We reviewed current blood conservation techniques and their use in cardiac surgery. Avoidance of aspirin preoperatively is an important blood conservation measure. Patients scheduled for an elective operation should participate in autologous predonation programs. With careful monitoring, patients with major coronary artery disease can safely donate blood preoperatively. Intraoperative processing of blood withdrawn before cardiopulmonary bypass provides autologous platelet-rich plasma for infusion after reversal of heparin sodium. Blood collected from the field during operation and blood remaining in the oxygenator after bypass can also be processed to yield washed and concentrated red blood cells for reinfusion. Randomized, prospective studies document that postoperative autotransfusion is both safe and effective in reducing homologous blood use. Aprotinin reduces plasma protein activation and platelet damage during bypass. The integration of available blood conservation techniques into a comprehensive program combined with careful consideration of the indications for transfusion may allow more patients to avoid transfusion entirely. 

Category: general pathological conditions
The case against childhood cholesterol screening Because some authorities have proposed blood cholesterol screening for children to prevent coronary heart disease, we reviewed published studies to estimate the potential risks and benefits of such screening. Childhood cholesterol levels are a poor predictor of high cholesterol levels in young adulthood and will be an even poorer predictor of coronary heart disease later in life. There is no evidence that blood cholesterol levels can be lowered more easily in children than in adults, and it seems unlikely that cholesterol reduction in childhood will be much more effective at preventing coronary heart disease than cholesterol reduction begun in middle age. Screening and interventions to lower blood cholesterol levels for millions of children would be expensive, could lead to labeling and family conflicts, and may cause malnutrition and increased noncardiovascular mortality. Because the benefits of cholesterol screening are unlikely to exceed these risks, we conclude that children should not be screened for high blood cholesterol levels. 

Category: cardiovascular diseases
Cytomegalovirus in the brain: in vitro infection of human brain-derived cells. Models for human cytomegalovirus (HCMV) brain infection have been developed in a variety of brain-derived cells in which the factors governing virus infectivity might be studied in vitro. Studies were initiated with brain endothelial cells, the likely portal of entry for virus into the central nervous system. Primary explant cultures of brain endothelial cells, derived from homogenates of healthy human brain, supported complete viral gene expression and cytopathic effect (CPE). Endothelial cells do not appear to be a barrier for HCMV passage into the central nervous system. Astroglial lines (primary explant or tumor-derived) varied in their ability to support HCMV replication. Some (T98G) supported incomplete (immediate-early) gene expression while others (A-172) did not support any detectable gene expression. Some astroglial lines (HS-683) supported extensive virus replication with minimal viral CPE. Neuronal cell lines (SK-N-MC) were fully permissive. The more differentiated glial lines (astrocytoma) were fully permissive to HCMV infection; however, the less differentiated glial lines (glioblastoma) were partly or nonpermissive. 

Category: neoplasms
A rare case of renovascular hypertension due to iatrogenic thoracoabdominal aortic dissection. A report of successful surgical treatment in childhood. Renovascular hypertension due to iatrogenic thoracoabdominal aortic dissection in an 8-year-old girl with aortic valvular stenosis is presented. A splenorenal arterial anastomosis without splenectomy was successfully performed. This procedure is considered best suited for children with thoracoabdominal aortic dissection as the autogenous graft is expected to grow and provide long-term patency. The spleen left in situ was expected to be advantageous, from the immunological aspect, at the time of open heart surgery for aortic valvular stenosis, which was anticipated in the near future in this child. 

Category: cardiovascular diseases
Very high blood pressure in acute stroke. In a study sample consisting of 388 unselected, consecutive acute stroke patients, 27 with systolic blood pressure greater than or equal to 200 mmHg and diastolic blood pressure greater than or equal to 115 mmHg were compared with the other 361 patients. The patients with high blood pressure were younger (65 vs. 73 years) and much more often had a history of hypertension (78 vs. 42%). Cardiac and vascular hypertensive manifestations were more frequent, particularly when only those patients with a history of hypertension were compared in the two groups. Alcohol abuse was mentioned in a higher proportion of hypertensives in the summaries of their medical records. No definite conclusions could be drawn with regard to the size and location of the brain lesions. Clinical symptoms did not differ between the groups, neither did the proportion of patients who could be discharged from hospital immediately. Mortality was higher in the high blood pressure group (30 vs. 14%, P less than 0.05). Thus the characteristics of patients with very high blood pressure were: younger age, much more frequent and severe previous hypertension. Alcohol abuse might be an important factor. The type, size and location of the brain lesion itself could not be statistically related to the high blood pressure, but very large lesions, particularly haemorrhages, might be associated with a reactive blood pressure response. 

Category: cardiovascular diseases
Awareness during caesarean section. Between 1982 and 1989 over 3000 patients were questioned about recall and dreaming after general anaesthesia for Caesarean section. Some 28 (0.9%) patients were able to recall something of their operation and 189 (6.1%) reported dreams. There was uniform adherence to a rigid anaesthetic protocol up to and including 1985, but a much publicized incident reported from the courtroom stimulated a relaxation of this regimen. Consequently the incidence of awareness decreased from 1.3% to 0.4%, and the incidence of dreaming was also reduced. Recollections of surgery were confined to manipulations, noises and voices. None of our patients complained of pain at the time of interview, although one since has. The inadequacies of the initial protocol and an approach to informed consent are discussed. 

Category: general pathological conditions
Multiple intracranial tumors of different cell types. Multiple intracranial tumors of different cell types are rare. We report nine patients with multiple intracranial tumors, who did not have a history of trauma, irradiation, or phacomatosis. The clinical, radiological, and histopathological findings as well as indications for operations in patients with asymptomatic second tumors are discussed. 

Category: neoplasms
Adenotin and adenotin-like proteins coexist with adenosine receptors in mammalian tissues. The relationship of adenotin, a low-affinity adenosine-binding protein, to adenosine receptors was examined in two human tissues and two mammalian cultured cell lines. An adenosine A2 receptor exists in the membranes from platelets, PC-12 cells, and JAR cells as shown by a stimulation of adenylate cyclase related to 5'-N-ethylcarboxamidoadenosine (NECA) or a NECA-related increase in intracellular cAMP levels. In contrast, binding studies with tritiated NECA revealed typical adenotin-like low-affinity binding sites on the membranes from the sources studied with agonist potencies as follows: NECA greater than 2-chloroadenosine greater than R-PIA. No evidence was found of coupling to a guanine nucleotide regulatory protein. Solubilization of platelet and placental membranes and precipitation with polyethylene glycol separated adenotin or the adenotin-like protein from a second adenosine binding site in each tissue. The pharmacologic properties of the precipitated binding sites were compatible with an adenosine A2 receptor in platelets and an adenosine A1 receptor in placenta. Our observations indicate that adenotin-like proteins exist outside the placenta. In addition, adenotin and adenotin-like proteins coexist with the adenosine A1 or A2 receptor in a number of cells and tissues and do not couple to a guanine nucleotide regulatory protein and stimulate adenylate cyclase. Therefore, adenotin is pharmacologically distinct from adenosine receptors, and its function remains to be discovered. 

Category: neoplasms
Mycoplasma pulmonis infections cause long-lasting potentiation of neurogenic inflammation in the respiratory tract of the rat. These experiments were done to learn whether Mycoplasma pulmonis infections of the respiratory tract of rats can potentiate "neurogenic inflammation" and whether this potentiation is amplified by factors that exacerbate the infections. Pathogen-free F344 rats were inoculated intranasally with M. pulmonis or with sterile culture medium and then lived for 4 wk in an ammonia-free atmosphere or in air containing ammonia (100 parts per million). Neurogenic inflammation was evoked by an intravenous injection of capsaicin, and 5 min later the magnitude of the response was quantified by measuring the amount of extravasation of two tracers, Monastral blue pigment and Evans blue dye. We found that vascular permeability in the tracheas of all rats was normal in the absence of capsaicin. However, a 75-micrograms/kg dose of capsaicin, which caused almost no extravasation of Evans blue in the tracheas of pathogen-free controls (17 +/- 3 ng/mg; mean +/- SE), produced extensive extravasation in the infected rats (135 +/- 18 ng/mg; P less than 0.001). Similarly, this dose of capsaicin produced 30 times as much Monastral blue extravasation in the infected rats (area density = 47 +/- 8% of surface area) as it did in the pathogen-free rats (1.6 +/- 0.5%; P less than 0.001), a difference that resulted from increases in the number of Monastral blue-labeled postcapillary venules and in the amount of labeling per venule. Exposure of the infected rats to ammonia exacerbated the infections, further increased the number of Monastral blue-labeled vessels and the amount of labeling per vessel, and made the rats so sensitive to capsaicin that a normally tolerable dose of 150 micrograms/kg i.v. caused fatal apnea. Ammonia did not have these effects in pathogen-free rats. We conclude that M. pulmonis infections of the airway mucosa cause a potent, long-lasting potentiation of neurogenic inflammation, which results in part from an increase in the number and responsiveness of mediator-sensitive postcapillary venules. These changes can be amplified by environmental factors such as ammonia which exacerbate the infections. 

Category: general pathological conditions
Acute myocarditis simulating myocardial infarction in a child. Pediatric chest pain usually occurs in benign conditions. However, this case portrays the dramatic electrocardiographic appearance of acute myocardial ischemia in a boy with biopsy-proven myocarditis who had only mild chest pain. This underscores the need for eliciting a detailed history when evaluating a patient with chest pain. If the pain cannot be clearly attributed to chest wall phenomena, or if there are historical or physical findings suggestive of an arrhythmia or angina, then further investigation with a chest radiograph and a 12-lead electrocardiogram is recommended. Myocarditis must be considered in the differential diagnosis of any child whose electrocardiogram is indistinguishable from an acute myocardial infarction. Finally, endomyocardial biopsy allows early diagnosis and institution of therapy, which may have beneficial effect on decreasing morbidity and mortality. Further follow-up and research is still needed to evaluate the effect of early treatment of myocarditis on long-term myocardial function and the development of chronic cardiomyopathy. 

Category: general pathological conditions
Ultrastructural changes in rat hearts following cold cardioplegic ischemia of differing duration and differing modes of reperfusion. Morphologic consequences of prolonged global hypothermic (15 degrees C), cardioplegic ischemia and two reperfusion techniques were studied in Langendorff-perfused rat hearts. A 'gentle' reperfusion technique, with gradual rise in perfusate temperature and pressure to physiologic levels over 30 min, was used for 12 hearts following 2-hour or 3 1/2-hour (6 in each group) ischemia. Abrupt reperfusion, with perfusate at 37 degrees C and 70 mmHg, was performed on 13 hearts (6 ischemic for 2 hours and 7 for 3 1/2 hours). Six nonischemic, perfused hearts served as controls. Randomly selected specimens from the left ventricle after 45-60 min reperfusion were prepared for transmission electron microscopy. Volume fractions of myocardial structural components were calculated from stereologic point-counting on the electron micrographs. Two-way analysis of variance revealed that interstitial edema developed with increasing ischemic time and was not influenced by reperfusion technique. The degree of endothelial damage was independent of ischemic time, but was lessened by 'gentle' reperfusion. Both mitochondrial injury and myocyte edema were less when perfusate temperature and pressure were slowly raised after 3 1/2-hour ischemia. 

Category: cardiovascular diseases
Venous infarction following the interhemispheric approach in patients with acute subarachnoid hemorrhage. Postoperative venous infarction following aneurysm surgery was studied in 48 patients with anterior communicating artery aneurysms operated on through the interhemispheric approach at the acute stage of subarachnoid hemorrhage (SAH). Of 23 patients whose bridging veins were sacrificed during surgery, 11 (47.8%) showed venous infarction in the frontal lobes. In contrast, only one (5.9%) of 17 patients whose bridging veins were preserved developed cerebral edema. None of eight patients who were operated on after Day 11 (the day of SAH was defined as Day 0) showed this complication, although bridging veins were sacrificed in six of them. Venous infarction following acute aneurysm surgery tended to occur more frequently in patients of higher SAH grade and/or more advanced age, but these correlations were not significant. However, the correlation between the sacrifice of veins and venous infarction was significant (p less than 0.025). Because this potential complication may compromise the benefit of acute aneurysm surgery and cause damage, it is important to preserve the venous system and in some instances to select another surgical approach based on the pattern of venous drainage in the frontal lobe. 

Category: general pathological conditions
Chronic upper lobe cavitary lung disease. Chronic upper lobe cavitary lung disease may be caused by infections, emphysema, cystic fibrosis, lung cancer, sarcoidosis and rheumatologic syndromes. The diagnostic evaluation includes a complete history, a physical examination, a chest radiograph, and sputum examination and culture. In some cases, computed tomographic scanning and biopsy are required. 

Category: general pathological conditions
Peripheral neuropathy associated with eosinophilia-myalgia syndrome. In 1989, the Centers for Disease Control recognized the existence of an epidemic illness characterized by myalgia and eosinophilia in individuals taking preparations containing L-tryptophan. We evaluated 3 patients with eosinophilia-myalgia syndrome who presented with subacute progressive neuropathies. The neuropathies were predominantly motor and maximal in the lower extremities. Two patients were confined to a wheelchair and one was ventilator-dependent and bedridden. Sensory loss predominantly involved small fiber modalities. Electrophysiological studies showed multifocal marked conduction slowing and conduction block indicating segmental demyelination, with associated axonal degeneration that was accentuated distally. Examination of sural nerve biopsy specimens demonstrated axonal degeneration in all 3 patients and perivascular infiltrates in 2. Levels of quinolinic acid, a neurotoxic metabolite of L-tryptophan, were elevated in the cerebrospinal fluid in the 2 patients in whom it was measured. The cause of the neuropathy is unknown but may include immune mechanisms or toxicity of eosinophils, L-tryptophan, its metabolic products, or contaminants within L-tryptophan preparations. 

Category: nervous system diseases
Long-term cardiopulmonary bypass by peripheral cannulation in a model of total heart failure. The decompression of the left heart through a percutaneous helical spring positioned within the lumen of the tricuspid and pulmonary artery valves. We performed long-term closed-chest cardiopulmonary bypass in an animal model of total heart failure (induced ventricular fibrillation). The extracorporeal system included a venous reservoir, a roller pump, a membrane lung, and a blood pulsator system. We cannulated the right external jugular vein for venous drainage and the right subclavian artery for arterial return. To decompress the left heart we passed by percutaneous cannulation a special helical spring mounted on a Swan-Ganz catheter (Baxter Edwards Divisions, Irvine, Calif.) and positioned it to rest within the pulmonary artery and tricuspid valves, which rendered them partly incompetent. After induced ventricular fibrillation, blood flow was raised to keep the central venous pressure at baseline values. The lungs were ventilated with 5% carbon dioxide in room air. During bypass, mean pulmonary artery pressure was 10.0 +/- 1.7 mm Hg, mean wedge pressure 11.9 +/- 1.8 mm Hg, and mean blood pressure 95.2 +/- 5.6 mm Hg. After 2 days (four animals) and 3 days (two animals) the hearts were defibrillated. There was immediate ejection from both sides of the heart. All sheep were weaned from bypass within 29 +/- 11 minutes and their lungs were ventilated with room air within 42 +/- 34 minutes. At autopsy hearts and lungs grossly appeared normal. We conclude that the percutaneous helical spring resting within right heart valves provided excellent decompression throughout the study, with full recovery of heart and lung function on defibrillation. 

Category: cardiovascular diseases
Resistance to d-tubocurarine in lower motor neuron injury is related to increased acetylcholine receptors at the neuromuscular junction The hypothesis that lower motor neuron injury, with its associated proliferation of acetylcholine receptors (AChR), induces resistance to the neuromuscular effects of d-tubocurarine (dTC) was tested in the rat. The left gastrocnemius was denervated by a 75-80% lesion of the sciatic nerve. The effective dose for 95% twitch depression (ED95) was studied in the denervated gastrocnemius and compared to the contralateral undenervated and sham-injured (control) gastrocnemius muscles approximately 2 weeks after injury. The AChR number was quantitated by the specific ligand 125I-alpha-bungarotoxin (125I-alpha-BT). Plasma dTC concentrations, measured by high-performance liquid chromatography (HPLC), were correlated to twitch tension during spontaneous recovery from neuromuscular blockade in the denervated animal. The ED95 (mean +/- SE) of dTC for the denervated leg was significantly (P less than 0.05) higher (0.26 +/- 0.06 mg.kg-1) than contralateral (0.16 +/- 0.03) and sham-operated left (0.13 +/- 0.03) legs. The twitch tension recovered to 50% of control twitch height at significantly (P less than 0.05) higher plasma dTC concentrations in the denervated (0.78 micrograms.ml-1) compared to contralateral (0.24 micrograms.ml-1) limb. The AChR number was significantly increased in the denervated limb (1041 +/- 96 fmol.mg protein-1) compared to contralateral right (109 +/- 4) and control left limb (113 +/- 11). There was a significant (P less than 0.05) positive correlation (R2 = 0.73) between ED95 and AChR number; that is, 73% of the variability in ED95 could be explained by changes in AChR. This study, therefore, confirms the hypothesis that proliferation of AChR after nerve denervation results in resistance to the neuromuscular effects of dTC. 

Category: nervous system diseases