shukoor65/lab-rag-model huggingface dataset:
Cerebral vasoconstriction during head-upright tilt-induced vasovagal syncope. A paradoxic and unexpected response. BACKGROUND. To determine the effect of vasovagally mediated syncope on the cerebral circulation, transcranial Doppler sonography was used to assess changes in cerebral blood flow velocity during head-upright tilt-induced syncope. METHODS AND RESULTS. Thirty patients (17 men and 13 women; mean age, 43 +/- 22 years) with recurrent unexplained syncope were evaluated by use of an upright tilt-table test for 30 minutes, with or without an infusion of intravenous isoproterenol (1-4 micrograms/min), in an attempt to provoke bradycardia, hypotension, or both. Transcranial Doppler sonography was used to assess middle cerebral artery systolic velocity (Vs), diastolic velocity (Vd), ratio of systolic to diastolic velocities, pulsatility index (PI = Vs-Vd/Vmean), and resistance index (RI = Vs-Vd/Vs) before, during, and after tilt. Syncope occurred in six patients (20%) during the baseline tilt and 14 (46%) during isoproterenol infusion (total positives, 66%). In the tilt-positive patients, concomitant with the development of hypotension and bradycardia, transcranial Doppler sonography showed a 75 +/- 17% decrease in diastolic velocity, unchanged systolic velocity, a 46 +/- 17% decrease in mean velocity, a 295 +/- 227% increase in pulsatility index, and a 73 +/- 34% increase in resistance index. CONCLUSIONS. These findings reflect increased cerebrovascular resistance secondary to arteriolar vasoconstriction distal to the insonation point of the middle cerebral artery. This is paradoxic because the expected response of the cerebral circulation to hypotension is vasodilation. We conclude that abnormal baroreceptor responses triggered during vasovagal syncope result in a derangement of cerebral autoregulation with paradoxic vasoconstriction in the face of increasing hypotension.
Abnormalities of gastrointestinal motility in children with nonulcer dyspepsia and in children with gastroesophageal reflux disease. In 11 children (mean age 44.2 months) with symptoms suggesting upper intestinal dysfunction (nonulcer dyspepsia), in nine children (mean age 27.3 months) with gastroesophageal reflux (GER) disease, and in seven controls (mean age 20.4 months) we investigated fasting [for 3 hr or until two migrating motor complexes (MMC) were observed] and fed (90 min) antroduodenal motility by means of perfused catheter system; furthermore, we measured both gastric emptying of a radiolabeled milk formula and fasting duodenogastric reflux during manometry by assessing bile salt concentration in gastric aspirates. No structural abnormalities of gastrointestinal tract and organic disorders were detected in the patients. In a high proportion of both groups of patients we found manometric abnormalities of interdigestive and fed motor patterns that were not seen in the controls: absence of antral phase III of MMC; significant decrease of antral and/or duodenal motor activity during fasting and/or fed periods; abnormal propagation or configuration of MMC phase III that was significantly shorter than in controls; bursts of sustained fasting and/or fed phasic duodenal activity, frequently uncoordinated with adjacent gut segments. When compared to controls, the mean intragastric concentration of bile salts during all MMC phases and the mean 1-hr percent gastric activity of the radiolabeled milk were significantly higher in the two groups of patients. We conclude that in a high proportion of children with nonulcer dyspepsia and of children with GER disease, gastrointestinal manometry may reveal significant irregularities of antral and duodenal motility, which are associated with increased duodenogastric reflux and delayed gastric emptying.
One-stage hypospadias repair: experience of 367 cases. Over a 6 1/2-year period we performed 374 primary hypospadias repairs, all but 7 as single-stage procedures. We usually employed the MAGPI, tubed preputial island flap and Mathieu reconstructions. Complications were comparatively few, with an overall incidence of 5% fistulae, 3% anastomotic strictures and 7% meatal retraction or stenosis. The cosmetic results were superior to those of staged procedures in that it was almost always possible to obtain a glanular meatus which was both terminal and realistic.
Early repair of iatrogenic injury to the ureter or bladder after gynecological surgery. Contrary to the traditional doctrine of delayed intervention in post-hysterectomy injuries of the ureter or bladder, the policy at our department has been to operate as soon as possible after the diagnosis is made. Of 68 patients (25 with vesicovaginal fistulas and 43 with ureteral injuries) early intervention was possible in 40 (59%). Primary healing was obtained in all patients. These results suggest that there is no disadvantage in early repair.
Perivalvular pseudoaneurysm complicating bacterial endocarditis: MR detection in five cases. Bacterial endocarditis usually affects the valve leaflets, but erosion into the valve anulus and adjacent myocardium may form a myocardial abscess. Perivalvular abscesses can drain into the ventricles or aorta, forming a life-threatening pseudoaneurysm. We reviewed our experience with cardiac MR imaging of this disorder. Fourteen patients with complicated bacterial endocarditis underwent ECG-gated spin-echo cardiac MR imaging in addition to conventional duplex two-dimensional echocardiography (2-D echo). Angiography was performed in seven patients, six of whom underwent surgery for valve replacement. MR imaging detected the pseudoaneurysms in all five of the surgically proved cases, while 2-D echo detected only three. Clinical follow-up suggested there were no false-negative examinations, but no autopsy data were available for confirmation. Postoperative MR imaging studies were conducted in three patients, revealing two recurrent pseudoaneurysms and one thrombosed aneurysm. Cardiac MR imaging provides useful pre- and postoperative information in patients with perivalvular pseudoaneurysms due to endocarditis.
Immunohistochemical detection of transforming growth factor-beta 1 in fibrotic liver diseases. Transforming growth factor-beta 1 was localized by means of immunohistochemical reaction in liver biopsy specimens taken from patients having different chronic liver diseases with extending fibrosis. Two polyclonal antibodies that were produced in rabbits were directed against the amino terminal of transforming growth factor-beta 1. Staining by anti-CC(1-30) was primarily extracellular and located in the portal and periportal fibrotic areas of all seven cases with chronic active hepatitis. No staining was noted in the four chronic persistent cases studied. A strong reaction was seen with the antibody in nine of the ten cirrhotic samples, whereas it was negative in one inactive cirrhosis case and in all five cases with normal liver histological findings. No positive staining could be detected by the anti-LC(1-30) in any of the liver tissues. Detection of transforming growth factor-beta 1 in active liver diseases at the site of fibrosis suggests that transforming growth factor-beta 1 might have a role in the process and progression of fibrosis during the development of the disease.
Elevated serum gastrin levels in patients with gastric cancer. Elevated plasma gastrin levels have been found in patients with colorectal cancer. We measured fasting serum gastrin levels in control subjects (n = 12), patients with gastric cancer (n = 43), and patients with carcinoma of the esophagus (n = 55). Serum gastrin levels were significantly higher in patients with gastric cancer compared to normal controls (P less than 0.005) and those with esophageal cancer (P less than 0.05). This information may add to our understanding of the pathogenesis of gastric cancer.
The nutcracker syndrome: new aspects of pathophysiology, diagnosis and treatment. Magnetic resonance imaging (MRI) was used to study vascular anatomy in 3 patients with the nutcracker syndrome and in 10 healthy volunteers. From these studies an abnormal branching of the superior mesenteric artery from the aorta was identified as being the cause of the nutcracker syndrome. Consequently, surgical transposition of the left renal vein to achieve an unobstructed renal venous backflow was performed successfully in 2 patients, while 1 underwent nephrectomy. In 1 patient adjuvant ureteral instrumentation became necessary to aid occlusion of persisting shunts between peripelvic venous varicosities and the urinary tract. Awareness of the pathophysiology of the nutcracker syndrome ensures an early diagnosis, which should be confirmed by a combination of diagnostic procedures, including MRI.
Localized necrotizing arteritis. A report of two cases involving the gallbladder and pancreas. We report two cases of localized necrotizing arteritis, one involving the gallbladder and one involving the pancreas. Both cases were found incidentally in surgically resected specimens. Vascular changes in both cases were similar to those seen in classic polyarteritis nodosa, involving medium-sized muscular arteries characterized by fibrinoid necrosis and panarterial and periarterial inflammations varying from active to resolving stages. Both patients had no constitutional symptoms or underlying serologic abnormalities suggestive of systemic angitis. To our knowledge, pancreas-limited arteritis has not previously been described. Whether these lesions represent an early manifestation of a systemic arteritides syndrome, a variant of polyarteritis nodosa, or a distinct entity should be prudently judged through a long-term follow-up.
Effect of oral propranolol administration on azygos, renal and hepatic uptake and output of catecholamines in cirrhosis. Circulating catecholamines are increased in cirrhosis with portal hypertension, and increase further after propranolol. In 23 cirrhotic patients, plasma norepinephrine and epinephrine were determined in an artery, the azygos vein, the right renal vein and a hepatic vein before and after an oral 80-mg dose of propranolol. Baseline azygos and renal venous norepinephrine levels were significantly higher than arterial norepinephrine levels (+20%, p less than 0.005; and +28%, p less than 0.001, respectively). Hepatic venous norepinephrine and all venous epinephrine values were below the arterial values (all p less than 0.05). After propranolol intake, arterial norepinephrine and epinephrine increased (+16%, p less than 0.01; and +93%, p less than 0.001, respectively). Significant increases in norepinephrine and epinephrine were found in azygos and renal veins (all p less than 0.01), whereas hepatic venous norepinephrine and epinephrine remained unchanged. Azygos and hepatic blood flow decreased after propranolol intake (-27%, p less than 0.05; and -16%, p less than 0.01, respectively). Azygos spillover of norepinephrine (an estimate of locally released norepinephrine delivered to the circulation) and clearance of epinephrine remained unaltered. Hepatointestinal clearance showed no significant change for norepinephrine, but showed a borderline-significant decrease for epinephrine (-23%, p = 0.08). Our results show a net production of norepinephrine in the prehepatic splanchnic area drained through superior portalsystemic collaterals and in the kidneys. The increase in circulating catecholamines after propranolol intake is probably due to a combination of further enhancement of sympathetic activity and a decrease in catecholamine degradation.
Use of polymerase chain reactions to monitor minimal residual disease in acute lymphoblastic leukemia patients. T-cell receptor (TCR) delta gene rearrangements are observed in more than 80% of acute lymphoblastic leukemia (ALL) patients. Moreover, a preferential usage of specific genetic elements has been shown in different ALL subtypes: V delta 1 DJ delta 1 rearrangements predominate in T-ALL, while most B-precursor ALLs show a recombination of V delta 2 to D delta 3. Recently we have proposed a strategy for the detection of minimal residual disease (MRD) based on the isolation of clonospecific probes following the in vitro amplification of V delta 1 DJ delta 1 junctions by polymerase chain reaction (PCR) and now have adapted this method to the preparation of specific V delta 2 D delta 3 fragments. In the present study, clonospecific probes were generated from 11 T-ALL and 16 cALL patients (21 children, 6 adults). The sensitivity of these 27 probes in detecting residual leukemia cells varied between 10(-4) to 10(-6) as determined by semiquantitative evaluation of dilution experiments. PCR analysis of 55 bone marrow (BM) and peripheral blood (PB) samples obtained from the 27 patients during complete clinical remission showed the following results: (1) Evidence for MRD was obtained in the BM of all patients (eight of eight) investigated 2 to 6 months after remission induction and also in 6 of 11 cases on maintenance therapy 7 to 19 months after diagnosis. (2) In contrast, all patients but one (10 of 11) analyzed 6 to 41 months after the termination of treatment lacked apparent evidence for leukemia DNA; the exception was a girl exhibiting 10(-4) to 10(-5) residual cells in her PB 5.5 years after diagnosis. (3) Longitudinal analysis in nine patients disclosed marked individual differences in the intervals between achievement of clinical remission and complete eradication of the leukemia cell clone. (4) Differences in the duration of MRD were not associated with distinct clinical-hematologic features. (5) Detection of residual disease by PCR proceeded clinical relapse in two cases.
Effects of diltiazem on long-term outcome after acute myocardial infarction in patients with and without a history of systemic hypertension. The Multicenter Diltiazem Postinfarction Trial Research Group. The effect of diltiazem on long-term outcome in patients with acute myocardial infarction with and without a history of systemic hypertension was investigated in 2,466 patients using the Multicenter Diltiazem Postinfarction Trial data-base. The baseline variables were comparable in the diltiazem and placebo-treated patients within the groups with and without hypertension. The initial 60-mg dose of diltiazem was associated with a significant (p less than 0.001) but modest (3%) reduction in blood pressure and heart rate in both groups with and without hypertension. Univariate and multivariate analyses revealed a meaningful overall reduction in first recurrent cardiac events (cardiac death or nonfatal reinfarction, whichever occurred first) and cardiac death in patients with hypertension treated with diltiazem compared with results in those treated with placebo. Similar effects were not observed in patients without a history of hypertension. When first recurrent cardiac events were used as the end point, the diltiazem:placebo hazard ratio (95% confidence limits) was 0.77 (0.58, 1.01) for the total hypertension group, and 0.67 (0.47, 0.96) and 1.32 (0.83, 2.10) for patients with hypertension with and without pulmonary congestion during the acute infarction, respectively. Similar results were observed using cardiac death as the end point. Beta blockers had a negligible effect on the hypertension-diltiazem relation. These findings suggest that diltiazem may exert a long-term beneficial effect in most patients with hypertension who do not have pulmonary congestion during an acute infarction, and a detrimental effect in the minority who have pulmonary congestion.
Automatic and effortful memory processes in elderly persons with organic brain pathology. This study investigated the automatic and effortful memory encoding model of Hasher and Zacks (1979) and the potential it may hold for aiding in the differentiation between aging-related memory decline and dementia. College students, normal elders, and dementia patients were compared on a 96-item picturebook task utilizing measures of free recall, recognition accuracy, memory for location, and memory for frequency. There were no differences between students and elders on any of the dependent measures. However, differences were found between elders and patients on each measure, and a discriminant function correctly classified the two groups with 93.3% accuracy. Subsequent discriminant analysis found patients could be correctly classified into diagnostic subgroups, i.e., dementia of the Alzheimer's type (DAT), multi-infarct dementia (MID), and Korsakoff's disease (KD) with 80.8% accuracy. The model holds promise as a guide for clinicians who are asked to make differential diagnoses of memory-impaired individuals.
Postpartum hypercalcemia in a patient with medullary sponge kidneys. Previous associations of primary hyperparathyroidism-induced hypercalcemia and medullary sponge kidney (MSK) have been reported. In this report, we describe a lactating woman MSK noted to be hypercalcemic throughout lactation, without evidence of hyperparathyroidism. After the baby was weaned, the serum calcium returned to normal. A bone biopsy performed while the patient was hypercalcemic was consistent with hyperparathyroidism, suggesting the presence of a parathyroid-like protein produced during lactation.
Survival determinants in extensive-stage non-small-cell lung cancer: the Southwest Oncology Group experience. We analyzed the 2,531-patient Southwest Oncology Group extensive-stage non-small-cell lung cancer (ENSCLC) data base from 1974 to 1988 to (1) assess the interactions of host- or tumor-related prognostic factors and therapy using Cox modeling and recursive partitioning and amalgamation (RPA) to determine whether each independently predicts outcome, and (2) use RPA to define prognostic subsets with different survival potentials. Good performance status (PS), female sex, and age greater than or equal to 70 years were significant independent predictors in a Cox model applied to the entire population. In a second Cox model for patients with good PS enrolled on recent studies, hemoglobin level greater than or equal to 11.0 g/dL, normal lactate dehydrogenase (LDH), normal calcium, and a single metastatic site were significant favorable factors. The use of cisplatin was an additional independent predictor of improved outcome in both Cox models after adjustments for year of accrual and all prognostic variables. The favorable effect of cisplatin was observed in each of six RPA-derived subgroups from the entire population. A second RPA of 904 patients from recent trials (nearly all received cisplatin-based therapy) resulted in three distinct prognostic subsets based on PS, age, hemoglobin, and LDH; greater than or equal to 1-year survivals were 27%, 16%, and 6% (P less than .0001). The best survival occurred for patients with a good PS who had a hemoglobin level greater than or equal to 11 g/dL and who were older than 47 years. This analysis suggests that although several factors were independent variables in the Cox models, three important prognostic subgroups were easily defined through RPA. Together with other analyses, our results suggest the need to modify the stage IV category in NSCLC.
Visceral and peripheral tissue perfusion after cardiac surgery. Visceral and peripheral tissue perfusion and oxygenation were studied in ten patients in the early phase after coronary artery bypass grafting. Visceral perfusion was assessed indirectly, by determining gastric intramucosal pH. As parameters of peripheral tissue perfusion and oxygenation, subcutaneous tissue PO2 (PscO2), transcutaneous PO2 (PtcO2). PtcO2 index (PtcO2/PaO2), laser-Doppler skin red-cell flux (RCF) and fingertip temperature (Tft) were recorded in the upper extremity. Central haemodynamics, rectal temperature and blood gases were also measured. The inspired oxygen concentration was maintained at 30 v/v%. Gastric intramucosal pH declined progressively during the first 3 hours in the intensive care unit, reached its minimum at 5 hours and thereafter slowly increased. The peripheral vascular bed was shut down on admission to the ICU, as indicated by low values of PscO2, PtcO2, PtCO2 index, RCF and Tft. These parameters began to rise after the next 2-4 hours and peaked by the end of the 8-hour study period, indicating complete opening of the peripheral vascular bed.
Neutrophil-endothelial cell interaction in critical illness. Sepsis syndrome frequently results in endothelial injury in many organ systems. To evaluate neutrophil-pulmonary endothelial cell interaction in the sepsis syndrome, we studied 39 critically ill patients prospectively and 20 normal volunteers. Thirteen patients with sepsis (mean age, 71.4 years), 14 patients in an intensive care unit control group (mean age 65.4 years), and 12 patients admitted with acute myocardial infarction (mean age, 66.8 years) were evaluated. Blood samples were drawn from septic patients within 24 hours and from ICU and MI patients within 72 hours of admission. All sepsis patients were culture positive, 6 of 13 from the blood. Both renal failure and ARDS developed in 54 percent of septic patients. 51Cr-labelled neutrophils were prepared and added to bovine pulmonary endothelial cell monolayers with and without added phorbol myristate acetate. Endothelial cells with adherent PMA and nonadherent PMN's, were harvested and radioactivity in each fraction measured with a gamma scintillation counter. Baseline and maximally stimulated (PMA, 3.0 ng/ml) neutrophil adherence to endothelial cells were similar in all patients groups. However, in septic patients, PMA-stimulated PMN adherence was reduced at lower doses, most significantly in those who developed ARDS within 24 to 48 hours of admission (p less than 0.05). Seventy-one percent of patients who developed ARDS had reduced stimulated adherence (PMA 1.0 ng/ml) compared to 22 percent of critically ill patients who did not. We conclude that diminished adherence of neutrophils to endothelium in response to low-level PMA stimulation is significantly more common in patients with sepsis who develop ARDS. Our findings suggest that PMN-endothelial cell interaction is altered by the time sepsis is clinically recognized but before the development of ARDS. We speculate that the observed reduction in adherence of the PMN to endothelial cells may be a consequence of down-regulation by mediators generated in the inflammatory response to sepsis and/or the need for active participation of septic endothelium in this interaction.
Systemic lupus erythematosus and lymphoma: association with antiphospholipid syndrome. A woman with a history of polyarthralgias appeared to develop systemic lupus erythematosus and lymphoma simultaneously. The diagnosis of the concurrent lymphoma was made on biopsy of a left axillary lymph node. Generalized lymphadenopathy, splenomegaly and pruritus had given rise to suspicion of an underlying lymphoma. The lymphoma responded well to chemotherapy. Her condition was further complicated by an arterial occlusion involving the right 2nd toe which was eventually amputated, transient ischemic attacks (amaurosis fugax), livedo reticularis and thrombocytopenia which were accompanied by elevations of IgM anticardiolipin antibodies and a biological false test for syphilis. The lupus anticoagulant test was not performed as she was given anticoagulation therapy.