Melricflash/CW_MedAbstractsAlt huggingface dataset:
Experimental contrast-associated nephropathy and its clinical implications. Acute renal failure after contrast media injection has been recognized for at least 35 years but the exact mechanism responsible for the renal injury remains an enigma. The clinical characteristics of contrast-induced nephropathy (CAN) are well-known although more recently the nonoliguric presentation has occurred at an increased frequency--in 70 to 90% of cases. For nonoliguric presentation of CAN, one can expect an asymptomatic increase in serum creatinine, the mean peak occurring at 4.2 days. If oliguric, the fractional excretion of sodium will be less than 1% and resistant to either fluid challenge or loop diuretics. Preexisting renal insufficiency, with or without diabetes mellitus, increases the risk of CAN 6- to 10-fold but recovery is expected, with less than 10% of all patients requiring dialytic support. Despite the growing body of published reports, the lack of a suitable animal model to evaluate various proposed mechanisms of renal injury has compromised our ability to devise a technique for preventing CAN. A popular scheme has been proposed to describe the possible sequence by which ischemia or nephrotoxins, or both, induce acute renal failure. In particular, a vascular mechanism (i.e., ischemia), is an appealing explanation for CAN since acute changes in renal hemodynamics after contrast media injection have been confirmed by several animal experiments. Unlike other vascular beds in which contrast media induce acute vasoconstriction followed by vasodilatation, the initial effect on the renal circulation is acute vasodilatation, followed by progressive vasoconstriction, increasing renal vascular resistance and a concomitant decrease in both renal blood flow and glomerular filtration rate. 

Category: cardiovascular diseases
Segmental vascular resistance in postobstructive pulmonary vasculopathy. Chronic unilateral pulmonary arterial ligation has been touted as a model of arteriopathy resulting in a tremendous increase in anastomotic bronchial flow (Qbr) via collaterals. To investigate its effects on the pulmonary vasculature, we ligated the left main pulmonary artery of seven dogs and 120 days later pump perfused their left lower lobes (LLL) via a cannula in the pulmonary artery at pulmonary arterial flow (Qpa) of 250 ml/min. We measured Qbr (330 ml/min) and compared LLL with control contralateral right lower lobes (RLL) and three LLL from normal dogs. Pressure-flow (P-Q) curves were obtained by varying Qpa. With arterial and venous occlusion we measured total, arterial, venous, and middle segment resistances under baseline conditions, after serotonin and histamine, either with or without Qpa and with antegrade and retrograde Qbr. Light microscopy was done postmortem. The slope of the P-Q curve was 33.4 mmHg.l-1.min in the ligated lobes compared with 15.9 in the controls, attributable by the occlusion technique mainly to a rise in arterial resistance (22.4 mmHg.l-1.min compared with 7.4 in the controls) with a small rise in venous resistance. This was explained by significant arterial medial muscle thickening and some loss of LLL volume. The arterial segment was markedly hypersensitive to serotonin, and the venous segment was mildly hypersensitive to histamine compared with controls. The occlusion data also enabled us to model the point of entry of the bronchial circulation into the pulmonary circuit at the precapillary level and to calculate bronchial vascular resistance. We conclude that postobstructive vasculopathy substantially raises pulmonary vascular resistance, mainly upstream from the site of entry of the bronchial circulation. The role of the latter may be to keep it from rising excessively in the segments it perfuses, i.e., the middle and venous ones. 

Category: cardiovascular diseases
Meningiomas involving the clivus: a six-year experience with 41 patients. A series of 41 meningiomas involving the clivus operated on from July 1983 to January 1990 is reported. The presenting symptoms and signs of these patients were similar to those reported previously. All the patients were evaluated by pre- and postoperative thin-section, high-resolution computed tomography using soft tissue and bone algorithms. Most of the patients also underwent magnetic resonance imaging. The regions of the clivus involved by tumor were divided into upper, middle, or lower regions on the basis of anatomical landmarks. The diameter of the tumor was measured in three axes, and a tumor volume and a tumor equivalent diameter were computed to categorize tumors as small, medium, large, or giant types. There were 9 medium, 27 large, and 5 giant tumors in this series. Some simple and some complex operative approaches were employed to effect tumor removal. Large and giant tumors often required more than one operative approach to remove the tumor. Intraoperative technical difficulties included tumor consistency, vascularity, dissection from the brain stem, and vascular and cranial nerve encasement. Postoperative computed tomographic scans documented total excision in 32 patients (78%). Residual tumor remained in the clival or cavernous sinus areas. These patients were either being observed, or were treated with gamma knife radiosurgery. There was one operative death due to pneumonia (2%), and three patients (7%) suffered permanent major neurological changes, presumably due to vascular occlusions in the posterior circulation. In the follow-up period, which ranged from 3 to 76 months, 2 patients (6%) with tumors that had appeared to be totally excised experienced recurrence. These patients were treated by a second operation, alone or in combination with radiation therapy. Two patients who had subtotal excisions (25%) had evidence of regrowth. In 2 patients, tumor growth continued despite gamma knife radiosurgery or external beam radiotherapy. 

Category: nervous system diseases
IgD immune complex vasculitis in a patient with hyperimmunoglobulinemia D and periodic fever. We describe a 27-year-old Dutch woman with the hyperimmunoglobulinemia D and periodic fever syndrome. During febrile attacks she occasionally presented with skin lesions on the distal parts of her upper and lower extremities, with the histologic picture of a leukocytoclastic vasculitis. Clear perivascular deposits of IgD and C3 were presented in early lesional skin on immunofluorescence investigation. Circulating IgD immune complexes were demonstrated on several occasions, both during and in between clinical attacks. These findings are consistent with an IgD immune complex-mediated pathogenesis for the skin lesions. In 10 patients with other forms of immune complex vasculitis of the skin, minimal perivascular deposits of IgD were found in four cases. In these cases, however, IgD was never found as the solitary immunoglobulin class. 

Category: general pathological conditions
Recovery profile after desflurane-nitrous oxide versus isoflurane-nitrous oxide in outpatients. Thirty-eight healthy outpatients undergoing elective surgical procedures lasting 1-3 h were randomly assigned to receive either desflurane 3% (approximately 0.5 MAC) or isoflurane 0.6% (approximately 0.5 MAC) for maintenance of general anesthesia with nitrous oxide 60% in oxygen after a standardized induction sequence consisting of fentanyl 3 micrograms.kg-1, thiopental 4 mg.kg-1, and succinylcholine 1-1.5 mg.kg-1, intravenously. Although anesthetic conditions were similar during operations in the two treatment groups, significant differences were noted in the recovery profiles as measured by elimination kinetics, psychometric testing, and visual analog scales (to assess subjective feelings). The time required for the end-tidal concentration to decrease by 50% was 2.5 +/- 0.8 min for desflurane vs. 9.5 +/- 3.4 min for isoflurane (mean +/- standard deviation [SD]). Times to awakening and ability to follow simple commands were significantly shorter after desflurane than after isoflurane (5.1 +/- 2.4 vs. 10.2 +/- 7.7 min 6.5 +/- 2.3 min vs. 11.1 +/- 7.9 min, respectively). Postoperatively, patients who received desflurane exhibited less impairment of cognitive function (as measured using the Digit-Symbol Substitution Test) than did those who received isoflurane. Furthermore, visual analog scores indicated that patients receiving desflurane experienced significantly less discomfort (pain), drowsiness, fatigue, clumsiness, and confusion in the early postoperative period. We conclude that desflurane may offer clinical advantages over isoflurane when used for maintenance of anesthesia during outpatient surgical procedures. 

Category: nervous system diseases
Radioimmunoscintigraphy using iodine-131-anti-CEA monoclonal antibodies and thallium-201 scintigraphy in medullary thyroid carcinoma: a case report. This case report demonstrates the use of thallium-201 (201Tl) scans versus iodine-131- (131l) anti-CEA F(ab')2 scans in a patient with high serum CEA levels due to metastases of medullary thyroid carcinoma in the suprarenal region and sacroiliacal region. Scintigraphy using monoclonal antibodies directed against CEA showed a higher tumor uptake (0.26% dose and 0.64% dose, respectively) than a thallium scan and is believed to be promising for future radiotherapeutic applications. 

Category: neoplasms
Comparison of pre- and postoperative conduction patterns in patients surgically cured of atrioventricular node reentrant tachycardia. Patients with atrioventricular (AV) node reentrant tachycardia characteristically have short and constant retrograde His-atrium conduction times (H2A2 intervals) during the introduction of ventricular extrastimuli. It has therefore been suggested that the tachycardia circuit involves retrograde conduction up an accessory pathway located in perinodal tissue. If the mechanism of surgical cure of AV node reentrant tachycardia is interruption of this accessory pathway, postoperative changes in retrograde conduction would be expected. Thirteen patients with drug-refractory AV node reentrant tachycardia underwent surgery. Preoperatively, H2A2 intervals were short and constant. During AV node reentrant tachycardia, earliest atrial activation was seen near the His bundle and was 0 to 25 ms before ventricular activation in all patients except one. Surgery consisted of dissection of right atrial septal and anterior inputs to the AV node and central fibrous body. Postoperatively, the H2A2 interval remained short and constant compared with preoperative values although it was slightly prolonged (74 +/- 18 versus 61 +/- 21 ms, p less than 0.005). Twelve of the 13 patients are free of tachycardia after 28 +/- 13 months and no patient has had evidence of AV node block. Thus, surgical cure of AV node reentrant tachycardia is highly successful; however, there is no reason to postulate an accessory pathway or use of perinodal tissue as part of the tachycardia circuit and the mechanism of surgical success remains obscure. 

Category: cardiovascular diseases
Mechanical ventilation in medical and neurological diseases: 11 years of experience. Mechanical ventilation (MV) is imperative in many forms of acute respiratory failure (ARF). The aim of this work was to review all episodes of MV in a Medical Intensive Care Unit (MICU) during the 11-year period 1976-1986. Four per cent (n = 1008) of 24,899 admissions to the MICU were treated with MV. The mean age of ventilator-treated patients was 53 +/- 18 years, and obviously it increased during the period of study. The average duration of MV was 4.7 d. MICU mortality, hospital mortality and 2-year mortality rates for patients subjected to MV were 33%, 38% and 46%, respectively. The mortality rate did not change during the study period. Cerebrovascular and malignant diseases carried the highest mortality rates, 75 and 79%, respectively, whereas mortality in patients ventilated because of drug overdose (n = 313) was only 2%. The results of this study confirm previously published findings concerning the outcome of MV, and we conclude that the effects of MV remain discouraging in medical and neurological patients. Improved quality of ventilator therapy and monitoring, as well as continued research directed at the causes of ARF, are equally important in reducing the mortality in ARF. 

Category: nervous system diseases
A manifesting carrier of Duchenne muscular dystrophy with severe myocardial symptoms. A 42-year-old so-called manifesting carrier of Duchenne muscular dystrophy (DMD), whose first complaints were severe myocardial symptoms, is described. Immunohistochemical study using anti-dystrophin anti-serum and analysis of cloned segments of X chromosome DNA were performed. Her two sons and one of her brothers appear to have had the same disease. She was admitted to the hospital complaining of dyspnoea, back pain and palpitations and was first diagnosed as having myocardial infarction. However, this diagnosis was excluded. The echocardiogram showed diffuse abnormalities of myocardial function. Serum enzymes were increased. Minimal weakness and decreased deep tendon reflexes were detected in her left lower extremity. Muscle biopsy revealed a small number of necrotic fibres. Immunohistochemical study using anti-dystrophin antiserum showed a mosaic pattern of the surface membrane. Analysis of cloned segments of X chromosome DNA from the patient and her son showed the XmnI(Asp) alleles of pERT 87-15 and the TaqI alleles of pERT 87-8 in both patients. 

Category: cardiovascular diseases
Influence of right bundle branch block on short- and long-term survival after acute anterior myocardial infarction The impact of right bundle branch block on long-term prognosis after anterior wall myocardial infarction is unclear. In 932 patients with Q wave anterior infarction, the short- and long-term prognostic significance of the presence of right bundle branch block was analyzed. Compared with 754 patients without block, 178 patients with right bundle branch block after myocardial infarction showed an increased incidence of left ventricular failure (72% versus 52%, p less than 0.001) and increased in-hospital (32% versus 8%, p less than 0.001) and 1 year after hospital discharge (17% versus 7%, p less than 0.001) cardiac mortality rates. The presence of right bundle branch block was an independent predictor of increased in-hospital and 1-year mortality when entered in a multivariate analysis. However, the absence of left ventricular failure identified a subgroup of patients with right bundle branch block with low in-hospital (4%) and 1 year postdischarge (5%) cardiac mortality rates comparable with those of patients with neither failure nor right bundle branch block (1.7% and 4.8%, respectively). In the presence of left ventricular failure, patients with associated right bundle branch block had higher in-hospital (43% versus 14%, p less than 0.01) and 1 year postdischarge (24% versus 9%, p less than 0.01) cardiac mortality rates than those of patients with failure but no right bundle branch block. Thus, the presence of right bundle branch block after anterior myocardial infarction is an independent marker of poor prognosis. 

Category: cardiovascular diseases
Local control of auricular, periauricular, and external canal cutaneous malignancies with Mohs surgery. Three hundred ninety-seven patients with 407 cutaneous malignancies of the auricle, periauricular region, and cartilaginous external ear canal were reviewed. Tumors were most commonly located in the preauricular and postauricular regions, followed by the helix, concha, antihelix, and ear canal. All lesions were excised with Mohs microscopic control of margins. For lesions requiring lateral temporal bone resection, an adaptation of fresh-tissue microscopic control was used to analyze deep and anterior margins suspected of harboring residual tumor. Two-year minimum follow-up of 229 patients with periauricular and auricular tumors (N = 231 tumors) and 14 patients with cartilaginous ear canal tumors (N = 14 tumors) revealed recurrence rates of 6.9% and 14.3%, respectively. Recurrences were most common in cases of large tumors (greater than 2.5 cm), basal cell carcinomas with morphea elements, and multiply recurrent lesions. We conclude that Mohs surgery is comparatively effective, though not uniformly curative, and can be adapted to supplement excision of large tumors in these regions. 

Category: neoplasms
Clinical features of misdiagnosed appendicitis in children. STUDY OBJECTIVE: To compare clinical features of children with misdiagnosed appendicitis with those of children with appendicitis initially diagnosed correctly. DESIGN: Retrospective review of hospital, emergency department, and clinic records. SETTING: University medical center with annual ED census of 40,000 patients. PARTICIPANTS: Children less than 13 years old admitted between May 1, 1979, and April 30, 1989, with a discharge diagnosis of appendicitis. MEASUREMENTS: Records were reviewed for historical, physical examination, laboratory, and pathologic features for all patients on their initial presentation to a physician and on final presentation during which the correct diagnosis was made. Using chi 2 analysis and Student's test, clinical features of misdiagnosed patients and patients diagnosed correctly were compared. RESULTS: One hundred eighty-one cases were identified with 50 initially misdiagnosed. On initial presentation, misdiagnosed patients were younger and more likely to have vomiting before pain onset, constipation, diarrhea, dysuria, and signs and symptoms of upper respiratory infections. Misdiagnosed cases were less likely to have right lower quadrant tenderness and documentation of bowel sounds, peritoneal signs, and rectal examinations. On final presentation, misdiagnosed patients were more likely to have pain duration of more than two days, temperature of more than 38.3 C, and to appear lethargic and irritable (P less than .05 for all measurements). CONCLUSION: Clinical features of children with misdiagnosed appendicitis differ from those of children with appendicitis initially diagnosed correctly. 

Category: digestive system diseases
Topical silicone gel for the prevention and treatment of hypertrophic scar. We studied the effects of a silicone gel bandage that was worn for at least 12 hours daily on the resolution of hypertrophic burn scar. In a second cohort, the prevention of hypertrophic scar formation in fresh surgical incisions by this bandage was also evaluated. In 19 patients with hypertrophic burn scars, elasticity of the scars was quantitated serially with the use of an elastometer. An adjacent or mirror-image hypertrophic burn scar served as a control. Scar elasticity was increased after both 1 and 2 months compared with that in controls. There was corresponding improvement clinically that persisted for at least 6 months. In the other cohort, scar volume changes in 21 surgical incisions were measured before and after 1 and 2 months. Gel-treated incisions gained less volume than control incisions after both intervals. Clinical assessment corroborated this quantitative demonstration of a decrement in scar volume. We concluded that topical silicone gel is efficacious, both in the prevention and in the treatment of hypertrophic scar. 

Category: general pathological conditions
Spontaneous rupture of liver during pregnancy: current therapy. Spontaneous hepatic rupture secondary to severe pregnancy-induced hypertension is associated with a high rate of maternal and fetal mortality. Numerous types of surgical management have been described, but a uniform surgical approach has not been accepted. The purpose of this review was to examine modes of surgical therapy reported in the literature since 1976, as well as the 11-year experience at our institution. Twenty-eight cases were extracted from the literature and seven more were identified at our institution. The incidence in our population was one per 45,145 live births. Among 27 cases managed by packing and drainage, an 82% overall survival was achieved, whereas only 25% of eight patients undergoing hepatic lobectomy survived (P = .006). Hepatic hemorrhage with persistent hypotension unresponsive to blood products should be managed by evacuating the hematoma, packing the damaged liver, and draining the operative site. More aggressive surgical techniques, such as hepatic artery ligation or hepatic lobectomy, should be reserved for refractory cases. 

Category: cardiovascular diseases
Bacteremia in an ambulatory setting. Improved outcome in children treated with antibiotics. We undertook a study of 414 bacteremic patients (167 with Haemophilus influenzae and 247 with Streptococcus pneumoniae bacteremia) to evaluate their clinical presentation, laboratory and clinical results, and subsequent outcomes. Patients with H influenzae bacteremia were more likely to have soft-tissue foci, poorer clinical appearance at presentation, and be at higher risk for subsequent serious focal infections, persistent bacteremia, and subsequent hospital admissions than patients with S pneumoniae. Patients with H influenzae bacteremia had a 21.1-fold increase in risk of meningitis (95% confidence interval [CI] of 3.8 to 78.0) compared with those with S pneumoniae. The odds ratio for initial lumbar puncture was 5.25 (95% CI [1.1-23.6]). Ambulatory patients treated with antibiotics at presentation were less likely to develop new serious soft-tissue infections, persistent bacteremia, or to require subsequent hospital admissions than untreated patients. The effect of treatment was greater for patients with S pneumoniae than those with H influenzae. Careful follow-up and reevaluation of patients with presumptive bacteremia is essential because treated and untreated patients can still develop serious soft-tissue infections. 

Category: nervous system diseases