123rc/medical_text huggingface dataset:
Nonuniform regional deformation of the pericardium during the cardiac cycle in dogs. We hypothesized that local contact forces between the pericardium and the heart cause regional variation in pericardial deformation during the cardiac cycle, reflecting volume changes of the underlying cardiac chambers. To test this, we measured regional pericardial area over the right atrium (RA) and right ventricle (RV) with orthogonal pairs of sonomicrometers in six open-chest dogs. At a left ventricular end-diastolic pressure of 5 mm Hg, RV pericardial area paralleled RV volume, that is, shrinkage during ejection by 10 +/- 8% and expansion during filling. RA pericardial area was reciprocally related to RV pericardial area, with average expansion during ventricular ejection of 2 +/- 2%, thus paralleling RA volume during RV ejection. With volume loading, RV pericardial shrinkage during ejection increased to 14 +/- 6%, but the RA pericardial area change was no longer reciprocal (0 +/- 3% change during RV ejection). Elimination of contact forces by cardiac tamponade resulted in both marked attenuation of RV pericardial area changes and synchronization of the RV and RA pericardial area pattern; that is, both shrank during RV ejection. In two additional dogs, measurement of pericardial area over left ventricle and atrium showed similar results. We conclude that dynamic pericardial contact forces cause regional variation in pericardial deformation, which reflects volume changes of the underlying chambers. These findings imply that the influence of the pericardium on filling and ejection may be more complex than previously recognized, varying both by chamber and dynamically over the course of the cardiac cycle.
Edge detection versus densitometry for assessing coronary stenting quantitatively. The optimal method used to analyze quantitatively the immediate angiographic results of coronary stenting in the coronary arteries has not been studied. Accordingly, minimal luminal cross-sectional area was determined by 2 methods, edge detection and densitometry, in 19 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) and then coronary stent implantation for symptomatic coronary stenoses. The correlation coefficient, 0.73 before angioplasty, decreased to 0.59 after coronary angioplasty and then increased to 0.83 after stent implantation. The mean differences between edge detection and densitometric determinations of minimal luminal cross-sectional area were 0.31 +/- 0.51 mm2 before PTCA, -0.38 +/- 1.22 mm2 after angioplasty and 0.35 +/- 0.79 mm2 after coronary stenting. It is concluded that, although the correlation and variability in the measurement of minimal luminal cross-sectional area between edge detection and densitometry deteriorate after PTCA, they are improved after stenting, probably because of smoothing of the vessel contours by the stent and remodeling of the stented segment into a more circular configuration. Therefore, in the stented coronary artery, edge detection and densitometry are equally acceptable methods of analysis.
Mucinous adenocarcinoma of the prostate with endobronchial metastasis. Endobronchial metastases can manifest clinical symptoms and x-ray findings mimicking a centrally located bronchogenic carcinoma. The authors recently encountered a case of endobronchial metastasis from a mucinous adenocarcinoma of the prostate that was originally diagnosed as a primary bronchogenic carcinoma. The correct diagnosis was made on the basis of the morphologic similarities between the primary prostatic lesion and the lung lesion and was corroborated by immunohistochemical analyses.
The Lewis X antigen. A new paraffin section marker for Reed-Sternberg cells. Using a monoclonal antibody specific to the Lewis X antigen (anti-Lex), the authors studied 103 cases of Hodgkin's disease (HD) in comparison with 57 cases of non-Hodgkin's lymphoma (NHL); three cases of granulocytic sarcoma (GS); two cases of malignant histiocytosis (MH); one case of monoblastic leukemia (ML); one case of interdigitating reticulum cell sarcoma (IRCS); six cases of histiocytosis X (HX); one case of reticulohistiocytoma (RH); 44 various reactive conditions of the lymph node (LN). Reed-Sternberg and related (R-S) cells stained selectively in 80 of 92 cases of HD (87.0%), excluding 11 cases of lymphocyte predominance type. The stain was better in B-5-fixed specimens than in formalin-fixed specimens, showing a dense deposit of reaction products at a paranuclear site and on the cell surface. The staining results were compared with those of Leu-M1 and found to be superior both qualitatively and quantitatively (detection rate of R-S cells: 87.0% versus 68.5% of Leu-M1). Granulocytes, rare epithelioid histiocytes, and some endothelial and/or erythrocytes also stained with anti-Lex. The stain had positive results in three cases of GS showing a diffuse cytoplasmic staining pattern. Of NHL, two of 29 peripheral T-cell lymphomas stained to show rare paranuclear deposits without cell surface staining. The stain had negative results in MH, ML, IRCS, HX, and RH. Of 45 reactive LN, minute subcapsular collections of Lewis X+, altered-appearing Langerhans'-like cells, were observed in all ten LN from human immunodeficiency virus (HIV)-associated persistent generalized lymphadenopathy (PGL). The stain had negative results in all other various reactive conditions of LN. In conclusion, Lewis X staining is useful as a marker for R-S cells in paraffin sections with staining results superior to those of Leu-M1. Lewis X staining also detects subcapsular clustering of altered-appearing Langerhans'-like cells in PGL, which has not been described previously and warrants additional study.
Effect of sleep and sleep deprivation on ventilatory response to bronchoconstriction. To characterize ventilatory responses to bronchoconstriction during sleep and to assess the effect of prior sleep deprivation on ventilatory and arousal responses to bronchoconstriction, bronchoconstriction was induced in eight asthmatic subjects while they were awake, during normal sleep, and during sleep after a 36-h period of sleep deprivation. Each subject was bronchoconstricted with increasing concentrations of aerosolized methacholine while ventilatory patterns and lower airway resistance (Rla) were continually monitored. The asthmatic patients maintained their minute ventilation as Rla increased under all conditions, demonstrating a stable tidal volume with a mild increase in respiratory frequency. Inspiratory drive, as measured by occlusion pressure (P0.1), increased progressively and significantly as Rla increased under all conditions (slopes of P0.1 vs. Rla = 0.249, 0.112, and 0.154 for awake, normal sleep, and sleep after sleep deprivation, respectively, P less than 0.0006). Chemostimuli did not appear to contribute significantly to the observed increases in P0.1. Prior sleep deprivation had no effect on ventilatory and P0.1 responses to bronchoconstriction but did significantly raise the arousal threshold to induced bronchoconstriction. We conclude that ventilatory responses to bronchoconstriction, unlike extrinsic loading, are not imparied by the presence of sleep, nor are they chemically mediated. However, prior sleep deprivation does increase the subsequent arousal threshold.
The appearance of the piriformis muscle syndrome in computed tomography and magnetic resonance imaging. A case report and review of the literature. The piriformis syndrome (PS) is a controversial cause of hip pain because of the lack of objective findings to support the diagnosis. Computed tomography (CT) and magnetic resonance (MR) imaging revealed PS in a 27-year-old woman. This case may be one of the first reports in the literature on a piriformis muscle enlargement documented by CT and MR imaging.
Klinefelter's syndrome with anomalous origin of left main coronary artery Klinefelter's syndrome is a rare entity. Even rarer is an anomalous origin of the Left Main Coronary Artery. For both conditions to occur in the same patient is hence exceedingly rare. Reported here is a never previously reported case of a coronary congenital anomaly in a patient with Klinefelter's syndrome together with the proper angiographic approach.
The diagnosis and definition of hepatic malignancies by use of arterial enhanced computerized tomographic scanning. Axial computerized tomography is a useful tool in the evaluation of either primary or metastatic hepatic neoplasms. An adjunct to this technique is visceral arterial enhanced computerized tomography (AECT). To determine the effectiveness of this modality, bolus intravenous enhanced computerized tomography scans and AECT were compared and correlated to operative findings. Fifty-four consecutive patients were evaluated by AECT and bolus intravenous enhanced computerized tomography over a 30-month period (May 1986 to August 1989) for suspected primary or metastatic hepatic malignancies. Forty-four patients (81%) had hepatic lesions. Fifty-two percent (23 of 44 patients) of the metastatic tumors were from colonic or rectal primary lesions, and 20% were hepatocellular primary lesions. The remainder of the lesions were metastases from a variety of primary lesions. When studies were compared, 34% of the patients (15 of 44 patients) differed in either the location or total number of lesions noted. The lesions of three of the 15 patients (20%) were determined unresectable on the basis of AECT. Of the remaining patients, planned resections were revised in seven patients to either lesser or greater procedures. The number of lesions found at laparotomy equaled the number found by AECT in all but two cases. AECT caused no complications. AECT improved our ability to identify and localize primary and metastatic lesions of the liver. This technique offers the advantage of preoperative definition of the hepatic arterial and portal venous anatomy.
Salvage of branch vessels during bifurcation lesion angioplasty: acute and long-term follow-up. To evaluate angiographic success, frequency of branch vessel loss and salvage, and long-term outcome, we studied the early and late outcomes of 56 consecutive patients who underwent PTCA of bifurcation lesions, which involved the left anterior descending or left circumflex coronary artery, with stenoses greater than 70% in both the parent and an involved branch vessel. In 35 patients (63%), the PTCA strategy was attempted dilation of both the main vessel and the involved branch vessels using predominantly a double-wire, sequential balloon technique; in 21 (27%) the PTCA attempt was confined to the main vessel alone. Transient angiographic occlusion of the branch vessel occurred in 32% of patients in whom dilation of both vessels was attempted, and in 38% in whom the main vessel alone was dilated (p = NS); 91% of the occluded branch vessels were the salvaged when sequential angioplasty of both vessels had been initially planned, compared to only 38% when the initial strategy had been dilation of the main vessel alone (p less than .05). Predischarge exercise testing showed residual ischemia in 6% of patients who had both vessels successfully dilated, versus 37% in those in whom dilatation was confined to the main vessels (p less than .01). Clinical restenosis, defined as late (greater than 6 weeks) recurrence of angina or a positive exercise test, occurred in 42% of patients who had both vessels successfully dilated. Thus although bifurcation lesion angioplasty frequently results in transient branch vessel loss, these branches can usually be salvaged using a double-wire technique but tend to have a higher late restenosis than conventional single vessel PTCA.
Massive histamine release in a patient with systemic mastocytosis. We have measured plasma histamine concentrations, systemic vascular resistance, cardiac output and arterial pressure during laparotomy in a patient with systemic mastocytosis. The patient developed vasodilation and hypotension during surgery, associated with a massive increase in plasma histamine concentration.
Superiority of transesophageal echocardiography in detecting cardiac source of embolism in patients with cerebral ischemia of uncertain etiology. The diagnostic yield of transesophageal and transthoracic echocardiography for identifying a cardiac source of embolism was compared in 79 patients presenting with unexplained stroke or transient ischemic attack. There were 35 men and 44 women with a mean age of 59 years (range 17 to 84); 52% had clinical cardiac disease. Both transthoracic and transesophageal echocardiograms were performed using Doppler color flow and contrast imaging. Transesophageal echocardiography identified a potential cardiac source of embolism in 57% of the overall study group compared with only 15% by transthoracic echocardiography (p less than 0.0005). Compared with transthoracic echocardiography, transesophageal echocardiography more frequently identified atrial septal aneurysm associated with a patent foramen ovale (9 versus 1 of 79 patients, p less than 0.005), left atrial thrombus or tumor (6 versus 0 of 79 patients, p less than 0.05) and left atrial spontaneous contrast (13 versus 0 of 79 patients, p less than 0.0005). All cases of left atrial thrombus or spontaneous contrast were identified in patients with clinically identified cardiac disease. In the 38 patients with no cardiac disease, transesophageal echocardiography identified isolated atrial septal aneurysm and atrial septal aneurysm with a patent foramen ovale more frequently than transthoracic echocardiography (8 versus 2 of 38 patients, p less than 0.05). The two techniques had a similar rate of identifying apical thrombus and mitral valve prolapse. Overall, transesophageal echocardiography identified abnormalities in 39% of patients with no cardiac disease versus 19% for transthoracic echocardiography (p less than 0.005). Thus, transesophageal echocardiography identifies potential cardiac sources of embolism in the majority of patients presenting with unexplained stroke.
Intra-abdominal palpation of a nasogastric tube in the stomach does not assure appropriate placement. Improperly placed nasogastric (NG) tubes have been associated with considerable morbidity. The only reliable indicator of correct NG tube placement appears to be the aspiration of gastric contents. We have reported a case of major morbidity from an improperly placed NG tube that perforated the cervical esophagus, dissected the mediastinum, and terminated in the omental bursa. No gastric aspirate was obtained by suctioning of the tube, but correct placement was presumed based upon the surgeon's direct intraoperative palpation of the tip of the tube. Failure to aspirate gastric contents should alert the practitioner to the possibility of improper NG tube placement.
A meta-analysis of the effect of estrogen replacement therapy on the risk of breast cancer [published erratum appears in JAMA 1991 Sep 11;266(10):1362] To quantify the effect of estrogen replacement therapy on breast cancer risk, we combined dose-response slopes of the relative risk of breast cancer against the duration of estrogen use across 16 studies. Using this summary dose-response slope, we calculated the proportional increase in risk of breast cancer for each year of estrogen use. For women who experienced any type of menopause, risk did not appear to increase until after at least 5 years of estrogen use. After 15 years of estrogen use, we found a 30% increase in the risk of breast cancer (relative risk, 1.3; 95% confidence interval [CI], 1.2 to 1.6). The increase in risk was largely due to results of studies that included premenopausal women or women using estradiol (with or without progestin), studies for which the estimated relative risk was 2.2 (CI, 1.4 to 3.4) after 15 years. Among women with a family history of breast cancer, those who had ever used estrogen replacement had a significantly higher risk (3.4; CI, 2.0 to 6.0) than those who had not (1.5; CI, 1.2 to 1.7).
High cardiac output as a paraneoplastic syndrome. A high cardiac output (17 1 min-1) was recorded in a young man suffering from lymphoplasmatocytotic lymphoma. The evolution of the blood disease was characterized by two relapses, during which clinical signs of heart failure were prominent but resolved with efficient blood chemotherapy. The known aetiologies of high cardiac output were excluded. The complete normalization of the cardiac parameters with blood remission suggests that the high cardiac output represented an unusual paraneoplastic syndrome, the pathogenesis of which still remains unknown, although several hypotheses were tested.
Advances in molecular biology. Potential impact on diagnosis and treatment of disorders of the thyroid. Advances in molecular biology research continue to have a major impact on clinical medicine. These advances have provided a means to produce proteins previously available in limited supply and allow for the production of novel proteins that are improved agonists or else antagonists with greater specificity for therapeutic targets. Newer drug delivery systems should facilitate delivery of these proteins. By combining the capabilities to produce drug targets in acceptable quantities with improved methods for determining the three-dimensional structures of these targets, novel organic therapeutic molecules that act on these targets will be designed. Gene transfer therapy using genes that express important proteins or that encode "antisense" RNAs that inhibit the translation of specific mRNAs will soon become a reality. The use of RFLPs and PCR methodologies promises increased means to diagnose specific genetic diseases and infections. Most importantly, molecular biology is helping to understand the mechanisms of disease such that novel diagnostic and therapeutic approaches can be described. These advances are providing an understanding of the mechanisms involved in cancers of the thyroid gland. They have already led to an enhanced understanding of (1) the growth factors that control proliferation of the thyroid gland, (2) the potential steps in thyroid nodule and neoplasia development, (3) particular mutations that may occur as thyroid cancers develop, (4) oncogenes that are expressed in thyroid cancers, and (5) the genetic defects that are responsible for thyroid gland malignancies in the multiple endocrine neoplasia (MEN) syndromes. With the latter, the RFLP technology has already provided an enhanced means to diagnose the disorder. With further progress, enhanced means for diagnosis and treatment should emerge. Molecular biology techniques are contributing to an increased understanding of the mechanisms of development of autoimmune thyroid disease as with Graves' disease and Hashimoto's thyroiditis. The potential role of infections, histocompatibility antigens, thyroid gland and extraglandular antigens, immune modulators, subpopulations of T-cells such as suppressor and helper cells, other cells involved in immune responses, and a combination of influences of several different functions on the thyroid gland are being defined. This knowledge should soon suggest improved means for diagnosis and treatment. Understanding of the function of the thyroid hormone receptors should have clinical importance. This knowledge suggests a means to develop thyroid hormone antagonists that may be used to more rapidly ameliorate the effects of hyperthyroidism and could be useful in nonthyroidal disorders such as cardiac arrhythmias.(ABSTRACT TRUNCATED AT 400 WORDS).
Pelvic lipomatosis associated with cystitis glandularis and adenocarcinoma of the bladder. Pelvic lipomatosis is a rare condition characterized by an overgrowth of normal fat in the perivesical and perirectal spaces. Cystitis glandularis, cystica or follicularis has been observed in 75% of the patients with pelvic lipomatosis. Although cystitis glandularis is widely regarded as premalignant few reports have documented its transition to adenocarcinoma. We describe a 41-year-old man with pelvic lipomatosis in whom primary adenocarcinoma of the bladder developed 6 years after a histological diagnosis of cystitis cystica and glandularis was established. To our knowledge this is the second case reported of pelvic lipomatosis associated with proliferative cystitis and adenocarcinoma of the bladder, indicating that intestinal metaplasia of the urothelium may be a precursor of malignancy in these patients.
An estimate of the incidence of dementia in idiopathic Parkinson's disease. The proportion of patients with idiopathic Parkinson's disease (PD) who are considered demented ranges from 10% to 15%. Because dementia may affect survival in PD, the incidence rate of dementia, rather than proportion, would be a more accurate measure of disease frequency. We previously estimated the proportion of patients with PD and dementia to be 10.9% from the records of a cohort with the idiopathic form of PD in a major medical center. We reviewed the clinical records of this cohort after 4 years and 9 months to estimate the incidence rate of dementia. We identified 65 new cases of dementia from the 249 patient-records available. Using the number of person-years of follow-up for each case as the denominator, we estimated the overall incidence rate to be 69 per 1,000 person-years of observation. The mean age of this cohort was 71.4 years. The cumulative incidence of dementia increased with age. By 85 years of age, over 65% of the surviving members of the cohort were demented. The age-specific incidence rates for dementia in this cohort of PD were significantly greater than for a similarly aged cohort of healthy elderly people. The age-specific standard morbidity ratios indicated that, compared with people of similar ages, patients with PD have the highest increase in risk for dementia between ages 65 and 75.
The TURP syndrome. This article discusses the presentation, aetiology, treatment and prevention of central nervous system disturbances after transurethral resection of the prostate. Nausea and vomiting, visual symptoms, and altered states of consciousness have been reported as complications due to intravascular absorption of irrigating fluid. Hypotonicity after absorption of the irrigating fluid causes cerebral oedema. Hyperglycinaemia may cause visual disturbances and hyperammonaemia may cause delayed coma.
Sensorineural hearing loss: a reversible effect of valproic acid. We report 2 patients over the age of 70 who, while on valproate (VPA) for complex partial seizures, developed sensorineural hearing loss. Following discontinuation of VPA for nonaudiologic reasons, the patients reported improved hearing which was confirmed by audiometry. These findings represent VPA-induced sensorineural hearing loss, possibly in preexisting presbycusis.
Vitamin C and cardiovascular risk factors. The concept that ascorbic acid (vitamin C) supplementation protects against coronary heart disease developed in the late 1970s when vitamin C intakes in industrialized nations were lower than at present. Supplementation was then shown to lower plasma total cholesterol and, among some elderly men, to raise high-density lipoprotein cholesterol. However, among people in initially good vitamin C nutriture, these effects are usually not seen. In five populations of essentially healthy people, blood pressure has been found to correlate negatively with vitamin C status. Recently, in a placebo-controlled, double-blinded study, extra ascorbic acid for 6 wk was observed to lower systolic and pulse pressure in a small group of borderline hypertensive subjects.