123rc/medical_text huggingface dataset:
IgG1-mediated acute pulmonary hypersensitivity response in the guinea pig. Involvement of specific lipid mediators. We determined the pulmonary obstructive response to aerosolized antigen challenge, and its sensitivity to antagonists of specific lipid mediators, in IgG, passively sensitized (IgG1-PS) guinea pigs. Antiovalbumin (OA)-IgG1 was isolated by affinity chromatography from serum derived from actively immunized Hartley guinea pigs. Propranolol and pyrilamine pretreated, IgG1-PS guinea pigs were challenged with aerosolized antigen and pulmonary obstruction was quantified by measurements of excised lung gas volume (ELGV). ELGV increased between 150 and 1,035% in a dose-proportional fashion with increasing antigen exposure (0.001 to 0.1% nebulizer concentration). The leukotriene antagonists ICI-204,219 and SKF-104,353 exhibited dose-proportional inhibitions in antigen-induced elevations in ELGV, inhibiting up to 65 and 87% at the maximal concentrations examined. Similarly, the platelet-activating factor (PAF) antagonists WEB-2086 and L-659,989 inhibited antigen-induced elevations in ELGV, inhibiting up to 94 and 59% at the maximal concentrations examined. In contrast, the cyclooxygenase (CO) inhibitor piroxicam significantly enhanced (p less than 0.05) the OA-induced elevations in ELGV. Aerosolized PAF challenge produced dose-proportional elevations in ELGV that were significantly inhibited by the LTD, antagonist ICI-204,219 (38 and 43% inhibition) and the CO inhibitor piroxicam (62 and 48% inhibition) in sensitized and nonsensitized animals, respectively. We hypothesize that IgG1-dependent airway obstruction is mediated in part by LTD, produced in response to PAF generation.
Recognition by ELAM-1 of the sialyl-Lex determinant on myeloid and tumor cells. Endothelial leukocyte adhesion molecule-1 (ELAM-1) is an endothelial cell adhesion molecule that allows myeloid cells to attach to the walls of blood vessels adjacent to sites of inflammation. ELAM-1 recognizes the sialyl-Lewis X (sialyl-Lex) determinant, NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc-, a granulocyte carbohydrate also found on the surface of some tumor cell lines. Binding of myeloid cells to soluble ELAM-1 is inhibited by a monoclonal antibody recognizing sialyl-Lex or by proteins bearing sialyl-Lex, some of which may participate in humoral regulation of myeloid cell adhesion. Stimulated granulocytes also release an inhibitor of ELAM-1 binding that can be selectively adsorbed by monoclonal antibody to sialyl-Lex.
Alterations in brain phosphate metabolite concentrations in patients with human immunodeficiency virus infection. Human immunodeficiency virus (HIV)-infected individuals often demonstrate neuropsychiatric impairment; however, it is unclear how brain metabolism may be altered in such patients. We used in vivo phosphorus 31 magnetic resonance spectroscopy to noninvasively assess brain energy and phospholipid metabolism by measuring brain concentrations of adenosine triphosphate (ATP), phosphocreatine (PCr), and inorganic phosphate (Pi), as well as phospholipid compounds and intracellular pH. In study 1, 17 HIV-seropositive men with varying degrees of neuropsychiatric impairment and six control subjects were studied. Localized spectra were obtained from a heterogeneous 5 x 5 x 5-cm volume of interest (VOI). Patients with HIV infection had a significantly lower ATP/Pi ratio and a trend for a lower PCr/Pi ratio than did the control group. In addition, the ATP/Pi and PCr/Pi ratios were both significantly negatively correlated with overall severity of neuropsychiatric impairment. In study 2, three HIV-seropositive men with neuropsychiatric impairment were compared with 11 HIV-seronegative men. Localized phosphorus 31 magnetic resonance spectra were obtained from two relatively homogeneous VOIs: (1) a predominantly white matter VOI, and (2) a predominantly subcortical gray matter VOI. The three HIV-infected patients demonstrated significantly decreased ATP and PCr concentrations in the white matter VOI. These results suggest that HIV infection of the brain may impair brain cellular oxidative metabolism and that the degree of metabolic compromise may be related to the severity of neuropsychiatric impairment.
Chiari pelvic osteotomy for osteoarthritis. The influence of the torn and detached acetabular labrum. We assessed the results of Chiari pelvic osteotomy in 64 hips with early osteoarthritis in terms of acetabular labral detachment detected pre-operatively by arthrography. At an average follow-up of four years, assessment by the Merle d'Aubigne score showed 83% excellent or good results. These satisfactory results were achieved in only half the cases with a detached labrum, but in nearly all cases with normal or torn acetabular labra. Other factors such as the acetabular index, the level and angle of osteotomy, and the displacement following osteotomy did not affect the results. Chiari pelvic osteotomy is a worthwhile procedure for early osteoarthritis in selected cases, but a detached acetabular labrum increases the risk of clinical failure.
Clinicopathologic and flow cytometric DNA study of medullary thyroid carcinoma. Sixty-one patients with medullary thyroid carcinoma were investigated to establish relationships between the neoplasm's DNA content, other clinicopathologic factors, and patient survival (at least 5 years' follow-up). There were 26 (42.6%) familial and 35 (57.4%) sporadic carcinomas. Forty-two neoplasms (68.8%) were diploid and 19 (31.2%) were aneuploid by flow cytometric assessment. In univariate analysis, age, hereditary background, DNA content, calcitonin immunoreactivity, and type of surgery were strong predictors of clinical outcomes. In multivariate regression analysis, none of these factors was an independent prognosticator. Patients' gender, clinical stage, histologic subtype, and amyloid content of the tumor did not influence survival.
Ventricular stroke work loss: validation of a method of quantifying the severity of aortic stenosis and derivation of an orifice formula Because aortic stenosis results in the loss of left ventricular stroke work (due to resistance to flow through the valve and turbulence in the aorta), the percentage of stroke work that is lost may reflect the severity of stenosis. This index can be calculated from pressure data alone. The relation between percent stroke work loss and anatomic aortic valve orifice area (measured by planimetry from videotape) was investigated in a pulsatile flow model. Thirteen valves were studied (nine human aortic valves obtained at necropsy and four bioprosthetic valves) at stroke volumes of 40 to 100 ml, giving 57 data points. Valve area ranged from 0.3 to 2.8 cm2 and mean systolic pressure gradient from 3 to 84 mm Hg. Percent stroke work loss, calculated as mean systolic pressure gradient divided by mean ventricular systolic pressure x 100%, ranged from 7 to 68%. It was closely related to anatomic orifice area with an inverse exponential relation and was not significantly related to flow (r = -0.15). An orifice formula was derived that predicted anatomic orifice area with a 95% confidence interval of +/- 0.5 cm2 (orifice area [cm2] = 4.82 [2.39 x log percent stroke work loss], r = -0.94, SEE = 0.029). These results support the clinical use of percent stroke work loss as an easily obtained index of the severity of aortic stenosis.
Esophageal contribution to chest pain in patients with coronary artery disease. We conducted a prospective study to determine the role of the esophagus in causing chest pain in patients with established CAD on optimum therapy. Thirty-two men with documented CAD who complained of frequent and usually daily retrosternal chest pain were evaluated. Following a standard esophageal manometry and acid perfusion test, simultaneous two-channel ambulatory Holter monitor and esophageal pH record tests were performed for 24 hours. Fifty-three episodes of chest pain were documented in 20 patients; 11 patients were free of pain. Of the 20 patients who complained of chest pains, 17 (85 percent) demonstrated at least one episode of PPR, defined as a drop in distal esophageal pH to less than 4 within ten minutes before or after the onset chest pain. Episodes of asymptomatic GER were common. The correlation of PPR with chest pain was 70 percent (37/53 episodes) and of ischemic ECG changes with chest pain 13 percent (7/53); in the remaining, there was no correlation with either. Two patients demonstrated simultaneous PPR and ischemic ECG changes. Seventeen esophageal motility abnormalities were observed in 14 patients (45 percent). It is our conclusion that esophageal disorders contribute to chest pain in patients with documented CAD. In this group, GER plays a greater role than in those with normal coronary arteries. In addition, esophageal motility disorders are common in these patients. Esophageal testing can be undertaken safely in these patients.
Cardioprotective effects of amlodipine on ischemia and reperfusion in two experimental models. The cardioprotective effect of amlodipine, a long-acting dihydropyridine derivative, was studied in 2 experimental models of ischemia and reperfusion. Isolated and blood-perfused feline hearts were made globally ischemic for 60 minutes and then reperfused for 60 minutes. Alterations of left ventricular developed pressure and compliance were monitored in both amlodipine-treated hearts and saline-treated control animals. Changes in perfusion pressure indicated that amlodipine significantly reduced myocardial oxygen consumption and coronary vascular resistance. Furthermore, a progressive increase in resting left ventricular diastolic pressure indicated that amlodipine, administered before the onset of global ischemia, attenuated the development of ischemic contracture. Return of contractile function 60 minutes after reperfusion and maintenance of tissue concentrations of electrolytes were significantly better in the amlodipine-treated group than in the control animals. In intact canine hearts, regional myocardial ischemia was induced for 90 minutes, followed by 6 hours of reperfusion. Although the hemodynamic variables and the size of the region of risk did not differ significantly between treated animals and control animals, the infarct size was significantly smaller in the amlodipine-treated group than in the control animals, and a gradual reduction in coronary blood flow was observed in the control group that was prevented in the amlodipine group. A comparison of these findings with those observed with oxygen radical scavengers also is discussed. A detailed report of these studies was published in The American Journal of Cardiology (1989;64:101I-116I). This review is included here to maintain continuity of the symposium for the convenience of the reader.
Intravenous fluid load and recovery. A double-blind comparison in gynaecological patients who had day-case laparoscopy. The effect of intra-operative fluid and dextrose administration upon recovery was tested in a randomised, double-blind trial. Three groups of 25 patients, each undergoing laparoscopic examination as day cases, were studied. The two groups who received fluid (20 ml/kg compound sodium lactate solution) showed significant improvement (p less than 0.05) in the variables that reflected hydration. The fluid group who also received dextrose (1 g/kg) exhibited further significant improvement. Intra-operative fluid and dextrose administration appears to confer some benefit upon recovery in patients who have minor surgery.
Post-chemotherapy tumor residuals in patients with advanced nonseminomatous testicular cancer. Is it necessary to resect all residual masses? A total of 15 patients with advanced nonseminomatous testicular cancer underwent 2 sequential operations (4 in 1 patient) to remove residual masses after cisplatin-based combination chemotherapy. All patients had normal human chorionic gonadotropin and alpha-fetoprotein levels but persistent radiographic masses after chemotherapy. The operations included retroperitoneal lymph node dissection in 13 patients, thoracotomy in 15, hepatic resection in 3 and craniotomy in 1. Histological comparison of the specimens resected during post-chemotherapy operations 1 and 2 demonstrated different patterns in 7 of 15 patients. Of these 7 patients 4 had less favorable pathological features in the specimen removed during the second procedure. Residual malignant tumor or mature teratoma was found in at least 1 site in 12 of the 15 patients and only 3 had complete necrosis or fibrosis in both specimens examined. These data indicate the favorable impact of excising all post-chemotherapy tumor residuals in patients with advanced nonseminomatous testicular cancer. However, in patients with no teratomatous elements in the testicular tumor and complete necrosis or fibrosis in the initial post-chemotherapy operation specimen the probability of complete necrosis or fibrosis in remaining tumors appears to be high.
Cation-dependent mannose 6-phosphate receptor contains two internalization signals in its cytoplasmic domain [published erratum appears in Proc Natl Acad Sci U S A 1991 Feb 15;88(4):1591] The signals required for rapid internalization of the bovine cation-dependent mannose 6-phosphate receptor have been localized to two distinct regions of the 67-amino acid cytoplasmic domain. One signal includes phenylalanine 13 and phenylalanine 18, while the other involves tyrosine 45. The former signal is more potent than the latter, but both must be present for the maximal rate of receptor internalization. Each signal shares similarities with the known internalization signals of other recycling receptors.
A controlled trial of community based coronary rehabilitation. Two hundred patients who had suffered an acute myocardial infarction 4-6 weeks before entered a randomised controlled trial of exercise treatment at a community sports centre supervised by a general practitioner. Eighty one per cent of the treatment group continued to exercise until they returned to work and 73% completed three months' exercise. There were no serious complications of the exercise course. The prevalence of angina pectoris fell by 10% in the treatment group but rose by 60% in the control group. The perceived energy level rose by significantly more in the treatment group than in the controls. The rise in predicted maximum oxygen uptake was significantly greater in the treatment group than in the control group as was the reduction in the double product (a reflection of myocardial workload) at peak exercise. Coronary rehabilitation in the community can be both safe and effective.
Lung beta-adrenoceptors in pulmonary hypertension. A study of biopsy specimens in children with congenital heart disease. Characteristics of beta-adrenoceptors were analyzed using radioligand-binding techniques with 3H-dihydroalprenolol in lung specimens from 11 children with pulmonary hypertension (median age, three years) undergoing surgical repair of congenital heart defects and four pediatric control subjects (median age, five years) undergoing thoracotomy for removal of neoplasms or cysts. Scatchard analysis of 3H-DHA binding to lung membranes showed similar values of the dissociation constant in both groups (Kd = 0.72 +/- 0.22 nM in patients vs 1.22 +/- 0.22 nM in controls; p = NS). The receptor density was significantly increased in patients in comparison with controls, with respective values of 164 +/- 19 and 95 +/- 13 fmol/mg of protein (p less than 0.025), and correlated directly with mean pulmonary arterial pressure (r = 0.82; p less than 0.0005). No significant relationship was observed between receptor number and pulmonary arterial medial thickness. Thus, the increase in receptor density in these patients may be related to adaptative changes in cells other than vascular smooth muscle.
Multiple arterial fenestrations, multiple aneurysms, and an arteriovenous malformation in a patient with subarachnoid hemorrhage. We report the case of a 49-year-old, right-handed man with multiple vascular pathologies, including a fenestrated anterior communicating artery and middle cerebral artery, an aneurysm of the anterior communicating artery, multiple aneurysms of the middle cerebral artery, and an arteriovenous malformation. Diagnoses were made through computed tomography, cerebral angiography, magnetic resonance imaging, and intraoperative dissection. The lesions were managed surgically in stages with satisfactory results. Congenital and hemodynamic factors may have combined to manifest in the anomalies present in this unique case. We believe that no similar combination of vascular pathology has been reported previously.
Sodium-potassium interaction in hypertension and hypertensive cardiovascular disease. Epidemiological evidence suggests that low potassium intake is associated with the probability of occurrence of hypertension and stroke. The short-term response to increased potassium intake is increased sodium excretion as well as increased potassium excretion; the short-term response to increased sodium intake is increased potassium excretion as well as increased sodium excretion. In some experimental studies, increased amounts of potassium have been able to block the noxious influences of sodium. Sodium and potassium must be concomitantly considered in the investigation of the association of either of these cations with hypertension and cardiovascular disease. The chloride ion is also important for sodium's effects; its importance in potassium's effects has not been extensively explored.
Modified Van Nes rotationplasty for osteosarcoma of the proximal tibia in children Above-knee amputation has been the traditional treatment for osteosarcoma of the proximal tibia. Recent advances in chemotherapy have encouraged the development of limb-salvage techniques. Van Nes rotationplasty for malignant lesions of the distal femur has increased in popularity as a reconstructive technique, but no similar procedure has been described for lesions of the proximal tibia. We have developed a modified rotationplasty for this lesion and have performed it in four children. The surgical technique, postoperative management and results of the procedure are described. Two patients had delayed wound healing. No other complications have developed and our patients were disease-free at follow-up, while the appearance of the leg was well accepted by the patients and their parents. This procedure is a useful addition to the armamentarium of the tumour surgeon for the treatment of malignant lesions of the proximal tibia.
Effects of low perfusate Ca2+ concentration on newborn myocardial function after ischemia. A greater dependence on transsarcolemmal Ca2+ flux and immaturity of Ca2+ sequestration capacity may potentiate Ca2(+)-mediated reperfusion injury in the newborn myocardium. The effect of serum ionized Ca2+ concentration on left ventricular systolic and diastolic function after ischemia was studied in 5-7-day-old piglets undergoing a 90-minute period of cold-blood cardioplegic arrest. In the control group, Ca2+ was maintained at 1.2 mM (Group A [n = 6]). The cardioplegic solution and bypass perfusate were modified to achieve a low Ca2+ concentration, 0.25 mM, in Group B (n = 6). Left ventricular pressure-volume loops were acquired by using high-fidelity pressure-sensor-tipped and volume-conductance catheters. Ventricular function was assessed from the slope of end-systolic (Ees) and end-diastolic (k) pressure-volume relations during transient caval occlusion. Both groups showed a significant reduction in Ees after ischemia (p less than 0.05). Intergroup comparison of Ees after ischemia demonstrated a better recovery of the systolic function in the low Ca2+ group, 64 +/- 7% versus 49 +/- 6% in the normal Ca2+ group (p = 0.05). There was a significant increase in chamber stiffness index in group A (k, 0.48 +/- 0.06 to 0.65 +/- 0.05 ml-1, p less than 0.01) versus no significant change in group B. This study shows 1) the feasibility of acquiring continuous pressure-volume data in neonatal hearts by using a conductance catheter system, and 2) better preservation of systolic function and diastolic compliance in normal newborn myocardium by low Ca2+ concentration in the peri-ischemic period.
Urovirulence determinants in Escherichia coli isolates causing first-episode and recurrent cystitis in women. To assess the prevalence of urovirulence determinants among Escherichia coli isolates from women with acute uncomplicated cystitis, 121 isolates from 87 women with first-episode or recurrent cystitis and 156 fecal isolates from 52 women without recent urinary tract infection were tested using DNA probes for P fimbriae, hemolysin, aerobactin, and diffuse adhesin and for expression of hemolysin and P and F adhesins. P fimbrial genotype (P = .002), hemolysin phenotype (P = .007), and the diffuse adhesin determinant (P = .03), but not aerobactin, were found more frequently in E. coli from women with acute cystitis, and expression of the F adhesin (41%) was more common than the P adhesin (24%; P = .001). E. coli isolates that caused cystitis in women using diaphragms had fewer virulence determinants than those from nonusers (P = .04), suggesting that diaphragm use may allow infection with less virulent E. coli.
Diagnosis of Lyme disease based on dermatologic manifestations. Lyme disease, or Lyme borreliosis, is an infection caused by the spirochete Borrelia burgdorferi, which is most commonly transmitted to humans by a tick bite. Characterized by early and late phases, Lyme disease is a multisystem illness involving the skin, heart, joints, and nervous system. Diagnosis is based predominantly on clinical manifestations, the most specific being dermatologic. Thus, recognizing the dermatologic manifestations of Lyme disease is important for diagnosis and institution of appropriate, effective therapy. Approximately 75% of patients with Lyme disease present with the pathognomonic skin lesion erythema migrans, an expanding erythematous lesion. During early infection, secondary erythema migrans lesions or Borrelia lymphocytoma may occur. Borrelia lymphocytoma commonly presents as an erythematous nodule on the ear lobe or nipple. During late infection, acrodermatitis chronica atrophicans, an erythematous, atrophic plaque unique to Lyme disease may appear; it has been described in about 10% of patients with Lyme disease in Europe. Fibrotic nodules associated with acrodermatitis chronica atrophicans as well as other sclerotic and atrophic lesions, such as morphea, lichen sclerosus et atrophicus, anetoderma, and atrophoderma of Pasini and Pierini, have been seen late in the course of Lyme disease. In a few cases, other sclerodermatous lesions, such as eosinophilic fasciitis and progressive facial hemiatrophy, have been linked to B. burgdorferi infection. We review the cutaneous lesions associated with Lyme disease.