shukoor65/lab-rag-model huggingface dataset:
Adenosine increases sympathetic nerve traffic in humans. BACKGROUND. Adenosine is an effective hypotensive agent in experimental animals and in anesthetized patients, producing little if any evidence of reflex sympathetic activation. In contrast, adenosine increases systolic blood pressure and heart rate in conscious subjects. To determine whether this response is related to sympathetic activation, we studied the cardiovascular and respiratory effects of adenosine in normal subjects while measuring muscle sympathetic nerve traffic through direct recordings from a peroneal nerve. METHODS AND RESULTS. Adenosine (80 micrograms/kg/min i.v.) increased heart rate (+32 +/- 3 beats/min), systolic blood pressure (+10 +/- 2 mm Hg), and minute ventilation (+7 +/- 1 l/min). This was accompanied by a dose-dependent increase in muscle sympathetic nerve activity (from 198 +/- 52 to 451 +/- 92 units/min). Adenosine also produced a small, but consistent, decrease in diastolic blood pressure (-6 +/- 3 mm Hg). Adenosine produced a greater increase in sympathetic nerve traffic (145 +/- 32% above baseline) than did nitroprusside (65 +/- 16%) at doses that resulted in equivalent decreased in diastolic blood pressure. Arterial baroreceptor unloading, therefore, could not totally explain the increase in sympathetic traffic produced by adenosine. CONCLUSIONS. Given the constellation of findings of increased ventilation and sympathetic activity, we, therefore, propose that adenosine increases sympathetic tone by activating afferent nerves, including arterial chemoreceptors. Contrary to the known inhibitory actions of adenosine on central and peripheral efferent systems, this and other reports suggest that adenosine-induced activation of afferent nerves, leading to sympathetic activation, may be a more widespread phenomenon than previously recognized.
Development of a new in vivo model for head and neck cancer. We have developed an improved model for studying in vivo nonsurgical treatment of head and neck cancer. In situ oral cavity implantation has been documented, but its natural history is not defined. In light of this, an improved model is described. Forty-two nude mice had tumor cells from one of two established laryngeal squamous cell carcinoma cell lines implanted into the floor of the mouth. The tumor mass was measured and followed. When the tumor burden was great enough to cause cachexia, the animals were killed and submitted for microscopic examination. Pulmonary metastases were noted in 44%, bone invasion in 80%, angioinvasion in 76%, and soft tissue invasion in 96% of the animals. Growth characteristics in the head and neck have not been documented in previous models. Our model not only exhibits the locally invasive activity typically associated with malignant neoplasms, but also closely parallels the results of clinical studies examining the percent of end stage patients and autopsies with pulmonary metastases. Therefore, this model should open the way for more meaningful in vivo studies of nonsurgical treatment modalities for both local and metastatic tumor foci in head and neck cancer.
Cystic duct cholangiography during laparoscopic cholecystectomy. At present, there is no consensus regarding the routine use of intraoperative cholangiography during cholecystectomy. We describe a reliable technique for performing cystic duct cholangiography during laparoscopic cholecystectomy. Using this technique, we were able to cannulate the cystic duct in 97% of patients, completely visualize the biliary tree and duodenum in 93% of patients, and identify unsuspected choledocholithiasis in 3% of patients. Treatment options for the management of choledocholithiasis demonstrated by cholangiograms during laparoscopic cholecystectomy include conversion to an open cholecystectomy and common duct exploration, or endoscopic sphincterotomy and common duct stone extraction following laparoscopic cholecystectomy.
Yersinia terminal ileitis: sonographic findings in eight patients. To determine the sonographic features of Yersinia terminal ileitis, we analyzed the sonograms of eight patients with acute terminal ileitis. Bacteriologic or serologic confirmation of Yersinia enterocolitica infection was available in six patients. In the other two, the clinical course and radiologic findings were compatible with the diagnosis. Radiographs and endoscopy showed edematous mucosa with small elevations in the terminal ileum in all the patients. Sonograms showed thickening of the wall of the ileum in all eight patients and enlarged mesenteric lymph nodes in six patients. Although the number of the patients is small, our experience suggests that sonography can be useful for the detection of acute terminal ileitis caused by Yersinia.
Immunoprecipitation of membrane proteins from rat basophilic leukemia cells by the antiganglioside monoclonal antibody AA4. In previous studies, mAb AA4 inhibited IgE binding, induced rapid morphologic changes, and blocked histamine release in rat basophilic leukemia (RBL-2H3) cells. It bound to two novel derivatives of ganglioside GD1b (Ag I and Ag II) that appear to be present only in rat mast cells. The present study demonstrates the importance of gangliosides Ag I and Ag II for binding of mAb AA4 to intact cells. We also investigated the presence of gangliosides Ag I and Ag II and proteins immunoprecipitated with mAb AA4 in the parental and four variant cell lines. In comparison with the parental RBL-2H3, two variant cell lines had very low (0.5% and 2.0%) and two others had intermediate levels (9% and 18%) of 125I-AA4 binding. mAb AA4 inhibited 125I-IgE binding to the parental RBL-2H3 cells and to only one variant with intermediate amounts of gangliosides Ag I and Ag II. Therefore, there are variations in the proximity of these gangliosides to the high affinity IgE receptor (Fc epsilon RI) among different cell lines. mAb AA4 immunoprecipitated proteins of 50 to 60, 120, and 135 kDa from 125I-surface labeled cells. These were different from the subunits of Fc epsilon RI. The amount of gangliosides Ag I and Ag II in cell extracts correlated with the number of mAb AA4 binding sites on the cell surface and with the quantity of proteins precipitated from the different cell lines. Thus, these membrane proteins appear to be associated with gangliosides Ag I and Ag II. The binding of mAb AA4 to the surface gangliosides could induce intracellular changes through transmembrane signaling by these proteins.
Borrelia burgdorferi-associated cutaneous B cell lymphoma: clinical and immunohistologic characterization of four cases. Four patients with low-grade malignant B cell lymphoma of the skin in association with chronic Borrelia burgdorferi infection are presented. Plaque-shaped or nodular erythematous lesions with ill-defined borders were seen. Clinical progression was slow; the skin tumors occurred for up to 7 to 15 years. Extracutaneous involvement was found in only one case. Immunohistologic investigations showed an expression of B cell markers with restriction to only one light chain type and absence of T cell antigens. The growth fraction was 5% to 30%, as shown with the monoclonal antibody Ki-67. The immunoarchitecture of the tumors in three patients was unusual compared with established criteria for cutaneous B cell lymphoma and revealed similarities to mucosa-associated B cell lymphoma. Some immunohistologic heterogeneity may indicate the development of monoclonal proliferation that originated from different phases of B lymphocytic differentiation. In three cases no clinical signs of B. burgdorferi infection were found; in one patient acrodermatitis chronica atrophicans was present. The occurrence of acrodermatitis chronica atrophicans and malignant lymphomas was frequently reported in the European literature before B. burgdorferi was recognized. These findings suggest a relation between B. burgdorferi infection and cutaneous B cell lymphoma. In geographic regions where infected ticks are present, borreliosis should be considered in patients with cutaneous B cell lymphoma.
Subacute bilateral coronary ostial stenoses following cardiac catheterization and PTCA. Accelerated coronary ostial stenosis is an infrequent late complication of coronary artery catheter instrumentation during aortic valve surgery, PTCA, or coronary angiography. We report the first case of bilateral coronary artery ostial stenoses developing after cardiac catheterization and right coronary artery PTCA. In patients with worsening angina following cardiac catheterization or PTCA, accelerated ostial stenoses should not be over-looked in the differential diagnosis.
Endoscopic and videofluoroscopic evaluations of swallowing and aspiration. A new procedure for evaluating oropharyngeal dysphagia utilizing fiberoptic laryngoscopy was compared to the videofluoroscopy procedure. Twenty-one subjects were given both examinations within a 48-hour period. Results of the fiberoptic endoscopic evaluation of swallowing (FEES) and videofluoroscopy examinations were compared for presence or absence of abnormal events. Good agreement was found, especially for the finding of aspiration (90% agreement). The FEES was then measured against the videofluoroscopy study for sensitivity, specificity, positive predictive value, and negative predictive value. Sensitivity was 0.88 or greater for three of the four parameters measured. Specificity was lower overall, but was still 0.92 for detection of aspiration. It was concluded that the FEES is a valid and valuable tool for evaluating oropharyngeal dysphagia. Some specific patients and conditions that lend themselves to this procedure are discussed.
Angiotensin converting enzyme inhibitors improve contractile function of stunned myocardium by different mechanisms of action. Angiotensin converting enzyme (ACE) inhibitors enhance contractile function of myocardium "stunned" by a brief episode of coronary artery occlusion, yet their mechanism(s) of action remain unresolved. In addition to possible hemodynamic effects, ACE inhibitors may stimulate the synthesis of cardioprotective prostaglandins. Furthermore, the beneficial effects of ACE inhibitors that contain a sulfhydryl group may be due in part to the ability of thiol compounds to act as nonspecific antioxidants or direct scavengers of cytotoxic oxygen-derived free radicals. To investigate this question we compared the effects of (1) the sulfhydryl-containing ACE inhibitor zofenopril, (2) the sulfhydryl-containing stereoisomer of captopril (SQ 14,534) with essentially no ACE inhibitor properties, (3) the nonsulfhydryl-containing ACE inhibitor enalaprilat, and (4) solvent alone, given at the time of reperfusion, on recovery of contractile function after 15 minutes of coronary occlusion in the anesthetized open-chest dog. Segment shortening in control animals remained depressed or "stunned" after reperfusion, recovering to only -5 +/- 12% of baseline preocclusion values at 3 hours after reperfusion. In contrast, all three treatment agents attenuated postischemic dysfunction: segment shortening was restored to 33 +/- 12%, 54 +/- 6%, and 83 +/- 5% of baseline values at 3 hours after reflow in dogs treated with SQ 14,534 (p less than 0.05), zofenopril (p less than 0.01), and enalaprilat (p less than 0.01), respectively (all vs control value). These improvements in segment shortening did not appear to be the result of altered oxygen supply or demand after reperfusion, inasmuch as no significant differences in systemic hemodynamic parameters or myocardial blood flow were observed among the groups. In the second phase of the study, we found that the improved contractile function associated with enalaprilat treatment could largely be reversed by infusion of the potent cyclooxygenase inhibitor indomethacin: segment shortening was reduced from 69 +/- 12% at 2 hours after treatment/reperfusion to 38 +/- 12% at 2 hours after indomethacin infusion (p less than 0.01 vs 2 hours after reperfusion). Infusion of indomethacin had no effect, however, on the improved contractile function associated with zofenopril treatment. We therefore conclude that sulfhydryl- versus nonsulfhydryl-containing agents enhance contractile function of stunned myocardium by different mechanisms of action: enalaprilat attenuates postischemic dysfunction at least in part by a prostaglandin-mediated mechanism, whereas the salutary effects of zofenopril and SQ 14,534 may be due in part to the antioxidant properties of the sulfhydryl moiety.
Relation between skin cancer and HLA antigens in renal-transplant recipients BACKGROUND. Recipients of renal allografts are at an increased risk for skin cancer. It is also known that recipients who are homozygous for HLA antigens are at an increased risk for certain cancers, as are those who are mismatched with their donors for these antigens. In a case-control study we assessed the relation between skin cancer in renal-transplant recipients and HLA homozygosity and mismatching. METHODS. Of 764 patients who received renal transplants between 1966 and 1988, 66 had squamous-cell carcinoma or basal-cell carcinoma of the skin after transplantation. HLA homozygosity was assessed in all 66 recipients, and HLA mismatching in 39; the results were compared with those in 124 recipients without skin cancer. We also investigated the relation between skin cancer and the use of immunosuppressive drugs. In separate case-control analyses we investigated the influence of exposure to the sun and keratotic skin lesions on the risk of skin cancer. RESULTS. The risk of squamous-cell carcinoma was increased in recipients mismatched for HLA-B antigens; the relative risks were 2.6 (95 percent confidence interval, 1.1 to 6.5) and 5.0 (95 percent confidence interval, 1.3 to 19.0) with mismatching for one and two antigens, respectively, as compared with no mismatching. Mismatching for HLA-A or HLA-DR antigens had no effect on the risk of squamous-cell carcinoma, and there was no association between mismatches at any of the HLA loci and the occurrence of basal-cell carcinoma. The total doses of azathioprine and prednisone were not associated with the occurrence of skin cancer or with HLA matching. Exposure to sunlight and keratotic skin lesions were strongly associated with skin cancer but not with HLA mismatching. Homozygosity for HLA-DR was more frequent among the patients with squamous-cell carcinoma (relative risk, 2.5; 95 percent confidence interval, 0.95 to 4.6) and among patients with 100 or more keratotic skin lesions (relative risk, 4.8; 95 percent confidence interval, 1.5 to 15.1). CONCLUSIONS. HLA-B mismatching is significantly associated with the risk of squamous-cell carcinoma in renal-transplant recipients, as is HLA-DR homozygosity. An indirect effect on the level of immunosuppression does not appear to explain these findings, nor does exposure to sunlight or the number of keratotic skin lesions account for this observation.
The peroxisome and the eye. Several childhood multisystem disorders with prominent ophthalmological manifestations have been ascribed to the malfunction of the peroxisome, a subcellular organelle. The peroxisomal disorders have been divided into three groups: 1) those that result from defective biogenesis of the peroxisome (Zellweger syndrome, neonatal adrenoleukodystrophy, and infantile Refsum's disease); 2) those that result from multiple enzyme deficiencies (rhizomelic chondrodysplasia punctata); and 3) those that result from a single enzyme deficiency (X-linked adrenoleukodystrophy, primary hyperoxaluria type 1). Zellweger syndrome, the most lethal of the three peroxisomal biogenesis disorders, causes infantile hypotonia, seizures, and death within the first year. Ophthalmic manifestations include corneal opacification, cataract, glaucoma, pigmentary retinopathy and optic atrophy. Neonatal adrenoleukodystrophy and infantile Refsum's disease appear to be genetically distinct, but clinically, biochemically, and pathologically similar to Zellweger syndrome, although milder. Rhizomelic chondrodysplasia punctata, a peroxisomal disorder which results from at least two peroxisomal enzyme deficiencies, presents at birth with skeletal abnormalities and patients rarely survive past one year of age. The most prominent ocular manifestation consists of bilateral cataracts. X-linked (childhood) adrenoleukodystrophy, results from a deficiency of a single peroxisomal enzyme, presents in the latter part of the first decade with behavioral, cognitive and visual deterioration. The vision loss results from demyelination of the entire visual pathway, but the outer retina is spared. Primary hyperoxaluria type 1 manifests parafoveal subretinal pigment proliferation. Classical Refsum's disease may also be a peroxisomal disorder, but definitive evidence is lacking. Early identification of these disorders, which may depend on recognizing the ophthalmological findings, is critical for prenatal diagnosis, treatment, and genetic counselling.
Five-hour balloon inflation to resolve recurrent reocclusion during coronary angioplasty [published erratum appears in Cathet Cardiovasc Diagn 1991 May;23(1):71] A 63-year-old male presented with an acute inferior myocardial infarction with initial clinical reperfusion following thrombolysis. Due to recurrent reocclusion, emergency catheterization was performed, demonstrating a 90% stenosis in the mid right coronary artery. Angioplasty was complicated by multiple reocclusions, ultimately requiring 5-h autoperfusion balloon inflation to maintain patency.
Exercise-induced ventricular tachycardia in association with a myocardial bridge. Sustained ventricular tachycardia induced by exercise is uncommon. This is a report of a patient who has a positive exercise test at a high level of exercise. The electrocardiogram has classic ischemic ST depressions. Following the appearance of these ST depressions, the patient developed ventricular tachycardia at a rapid rate. Workup that included an echocardiogram and cardiac catheterization revealed myocardial bridging of the left anterior descending artery as the only structural abnormality. Electrophysiologic studies revealed the patient to have ventricular tachycardia only with isoproterenol (Isuprel) infusion.
Intraarterial portography with gadopentetate dimeglumine: improved liver-to-lesion contrast in MR imaging. Magnetic resonance imaging during arterial portography (MRAP) was performed by the authors in a selected group of 12 patients with hepatic lesions. A low dose of gadopentetate dimeglumine (4 mL of a 0.5-mol/L solution, corresponding to a dose of 0.05-0.07 mmol/kg) was injected into the superior mesenteric artery during acquisition of breath-holding gradient-echo or rapid acquisition spin-echo images. Images were always acquired during the first passage of gadopentetate dimeglumine through the liver parenchyma. An increase in liver-to-lesion contrast was obtained with MRAP imaging (contrast-to-noise ratio = 8 +/- 1.8 vs 19 +/- 2.7). Signal intensity enhancement of the liver was high (signal-to-noise ratio = 9.48 +/- 2.42), while the lesion presented no significant enhancement (signal-to-noise ratio = 0.55 +/- 0.22). Lobar portal vein thrombosis was detected in one patient owing to lack of enhancement of the left lobe of the liver. No side effects related to administration of iodinated and paramagnetic contrast agents were observed. This new technique provides specific enhancement of liver parenchyma with improved liver-to-lesion contrast.
Improved detection of hypotension by automated noninvasive blood pressure monitoring. This study was undertaken to determine whether the use of automated noninvasive blood pressure monitoring altered the frequency of detection of intraoperative hypotension. We retrospectively reviewed 1,861 anesthetic records from a period in 1987, when blood pressure was obtained manually by auscultation. We compared the records from 1987 with 1,716 anesthetic records from 1989, when automated blood pressure monitors were used universally. The incidences of hypotension requiring vasopressor therapy were determined during the two periods and compared using Student's two-tailed t test. The data revealed that the incidence of detected hypotension increased from 2.4 to 5.2% with the use of automated blood pressure monitors (P less than 0.00002). We conclude that at our hospital the use of automated noninvasive blood pressure monitors increases the incidence of detection of intraoperative hypotension as compared with the use of manual blood pressure measurement.
Mucinous carcinomas of the colon and rectum. An analysis of 62 stage B and C lesions. The significance of a large extracellular mucinous component in colorectal adenocarcinomas continues to be controversial. We studied 62 stage B and C mucinous carcinomas defined by 60% or greater mucinous component. Sixty of these patients had matched nonmucinous adenocarcinoma controls. Patients with mucinous carcinomas with a residual adenoma had a significantly greater survival than those who did not. Overall, no difference was noted in 5-year survival between patients with mucinous carcinoma and nonmucinous adenocarcinoma (64% each). However, when the stages were considered separately, patients with stage B mucinous carcinoma fared significantly worse and had more local sites of treatment failure. We speculate that patients with stage B mucinous carcinoma may have a worse prognosis owing to the extra-cellular mucin, which may make a complete surgical extirpation more difficult.
Urokinase-type plasminogen activator is expressed in stromal cells and its receptor in cancer cells at invasive foci in human colon adenocarcinomas. In this study in situ hybridization methods were used to examine biopsy samples from 13 adenocarcinomas of the colon for the presence of mRNA for the urokinase-type plasminogen activator (u-PA) and its specific cell-surface receptor (u-PAR). In all cases, u-PA mRNA was present in fibroblastlike cells in the stroma adjacent to the invasive tumor nodules. Urokinase-type plasminogen activator mRNA was not detected in the malignant cells. All specimens also contained u-PAR mRNA in cells located at the tumoral-stromal interface of invasive foci, but in contrast at least some of these cells were in all but one case identified as being of malignant origin. Stromal cells, probably tumor-infiltrating macrophages and neutrophils, also were positive in these areas. These results support the view that components of the plasminogen activation system may act to influence proteolytic events occurring at the interface between stroma and malignant cells in adenocarcinomas of the colon in humans.
Mechanisms of tubulointerstitial fibrosis. With regard to tubulointerstitial fibrogenesis we are left with a variety informational gaps regarding nearly all aspects of this clinically important process. Table 2 summarizes a generalized version of fibrogenesis based primarily on investigations in other organs. Extrapolation of data obtained with other fibrogenic systems is useful, but only in so far as it motivates us to adapt and test many of the experimental principles within in the context of the kidney. This begins with a comprehensive examination of the in vivo state, the establishment of adequate animal models, and the dissections of the process in vitro. Key areas for the future are the characterization of the signals involved, the cellular responses to these signals, and the variations in interactions produced by differing inciting fibrogenic conditions.
A case of gastric plasmacytoma: genetic analysis and immunofixation electrophoresis. A case of early gastric plasmacytoma in a 66-yr-old woman is reported. The demonstration of monotypic IgM lambda immunoglobulin in plasma cells infiltrating the gastric antrum contributed the histological diagnosis. Genetic analysis of the tumor cells confirmed the presence of a monoclonal neoplastic population of plasma cells in the tumor. Monoclonal immunoglobulin (IgM lambda) was demonstrated in serum, not by conventional immunoelectrophoresis, but by a highly sensitive immunofixation electrophoresis technique. Serum monoclonal immunoglobulin disappeared after subtotal gastrectomy. The value of immunofixation electrophoresis of serum protein and DNA analysis of tumor cells was emphasized for the diagnosis of gastric plasmacytoma.