shukoor65/lab-rag-model huggingface dataset:
Pharmacokinetics of esmolol in children. The pharmacokinetics and concentration-response relationships of intravenous esmolol were investigated in 20 children undergoing indicated cardiac electrophysiologic testing. A loading dose of 600 micrograms/kg was infused for 2 minutes. An infusion of esmolol was initiated and dosage was titrated until beta-blockade occurred. Serial esmolol blood samples were obtained for pharmacokinetic analysis. Non-compartmental pharmacokinetic analysis of the data revealed the following parameter estimates (mean +/- SD): volume of distribution at steady state, 2.0 +/- 1.4 L/kg; total body clearance, 321.2 +/- 238.8 ml/kg/min; and terminal elimination half-life, 4.5 +/- 2.1 minutes. There was a significant correlation between mean esmolol concentrations and mean percentage of reductions of mean arterial pressures and heart rates at each sample time (p less than 0.001). The doses of esmolol required for beta-blockade (mean +/- SD, 535 +/- 180 micrograms/kg/min) in children were considerably higher than those typically used in adults. Esmolol should prove useful in children in the acute management of cardiac arrhythmias and hypertension.
Activity of esorubicin in recurrent malignant lymphoma: a Southwest Oncology Group study. A phase II trial of esorubicin (4' deoxydoxorubicin) was conducted by the Southwest Oncology Group in 88 assessable patients with non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) at the time of first relapse. Esorubicin was administered at two dose levels: 25 mg/m2 for patients at risk for excessive myelosuppression, and at 30 mg/m2 for all others at 21-day intervals. Overall, 33 of 88 patients (38%) responded to treatment including three complete remissions (CRs; 3%) and 30 partial remissions (PRs; 34%), with the median duration of response lasting 6.2 months. Response rates did not differ significantly by histologic subtype: 31% of 26 patients with favorable NHL, 33% of 43 patients with unfavorable NHL, and 58% of 19 patients with HD. Twelve of 33 responding patients (36%) had relatively durable remissions lasting from 1 to more than 4 years. Leukopenia (less than 3,000 cells per microliter) was seen in 65 of 88 patients (74%) and was severe (less than 1,000 cells per microliter) in 20 of 88 patients (23%). Clinical signs or symptoms of congestive heart failure were not seen and the ejection fraction (EF) fell 10% to 20% in three patients. Esorubicin is an active agent in patients with NHL or HD at the time of first relapse.
Preventability of emergent hospital readmission To determine whether emergent readmissions within 30 days of discharge are potentially preventable, we prospectively studied all readmissions to the medical service of a university teaching hospital during a 4-month period. The 327 readmissions, including 42 patients who were readmitted more than once during the study period, accounted for 12% of medical admissions. Nearly 75% of readmissions were due to previously diagnosed medical conditions; complications of drugs or therapeutic procedures caused 29%, and patient compliance contributed to 11%. Three reviewers judged 28 (9%) readmissions to be potentially preventable. These 28 readmissions constituted 1% of all admissions to the medical service and did not result in any fatalities, indicating that the quality of care was generally very good. One third of the potentially preventable readmissions were thought to be related to medical system failures, one third to an unfulfilled hope that the patient would improve after discharge, and one third to other suboptimal judgements in evaluation or treatment. Of the 28 potentially preventable readmissions, 89% occurred within 10 days of discharge. We conclude that potentially preventable readmissions would nearly always be detected by review of readmissions within 10 days of discharge and that many may be amenable to systematic interventions such as standardized predischarge assessment and better coordination of post-discharge follow-up.
Role of lymphadenectomy in renal cell carcinoma. A hilar or limited lymph node dissection will not remove the primary lymphatic drainage area of either kidney. For a lymphadenectomy to have a therapeutic benefit, an extended dissection is required, particularly for right-sided tumors. An extended lymphadenectomy may not be justified in all patients with renal cell carcinoma, particularly those with small tumors (who rarely have lymphatic disease) or grossly positive nodes (who have a high risk of existing distant metastases). For some patients with T3 or V+ tumors and palpably normal retroperitoneal nodes, an extended nodal dissection may resect microscopically involved nodes and result in an improved survival rate. This hypothesis will not be tested appropriately until a randomized controlled study is performed.
Torsion dystonia genes in two populations confined to a small region on chromosome 9q32-34. Idiopathic torsion dystonia (ITD) is characterized by sustained, involuntary muscle contractions, frequently causing twisting and repetitive movements or abnormal postures. Most familial forms of ITD display autosomal dominant inheritance with reduced penetrance. Linkage analysis has been previously used to localize a dystonia gene to the 9q32-34 region in a large non-Jewish family and in a group of Ashkenazi Jewish families. Utilizing GT repeat polymorphisms from this region, here we demonstrate that the gene causing dystonia in Ashkenazi Jews can be localized to the 11-cM interval between AK1 and D9S10. Linkage analysis in the non-Jewish family is also consistent with occurrence of the gene in this region, although positive lod scores extend over a greater than 20-cM interval in that family. These results set the stage for positional cloning of the dystonia gene. Currently there are no known candidate genes in this region.
Prophylaxis of atrial fibrillation with magnesium sulfate after coronary artery bypass grafting. Ninety-nine consecutive consenting patients were prospectively entered into a randomized, double-blind, placebo-controlled trial to determine the efficacy of postoperative magnesium therapy on the incidence of cardiac arrhythmias after elective coronary artery bypass grafting. No patient had documented or suspected arrhythmias preoperatively. Forty-nine patients received 178 mEq of magnesium given over the first 4 postoperative days, and 50 patients received only placebo. The clinical characteristics of both groups were similar. The preoperative mean serum magnesium concentration was similar in both study (1.90 mEq/L) and placebo (1.90 mEq/L) groups. The mean postoperative serum magnesium concentration in study patients was significantly elevated over postoperative days 1 through 4 when compared with preoperative levels (p less than 0.001). The postoperative mean serum magnesium concentration in control patients declined and remained significantly depressed through postoperative day 3 (p less than 0.001), but increased to preoperative levels by postoperative day 4. The mean serum magnesium concentration was significantly greater in the study patients as compared with the control patients over postoperative days 1 through 4 (p less than 0.001). Although there was no significant difference between groups with respect to episodes of ventricular arrhythmias, there was a significant decrease in the number of episodes of atrial fibrillation in the group receiving magnesium therapy (p less than 0.02). There were no recognized adverse effects of magnesium therapy. Prophylactic magnesium administration seems to lessen the incidence and severity of atrial fibrillation after coronary artery bypass grafting.
U-78517F: a potent inhibitor of lipid peroxidation with activity in experimental brain injury and ischemia. U-78517F (2-[4-[2,6-di-(1-pyrrolidinyl)-4-pyridinyl)-1-piperazinyl] methyl]-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol, dihydrochloride), which combines the antioxidant ring portion of alpha-tocopherol together with the amine of the previously described 21-aminosteroids (e.g., U-74006F), is a novel inhibitor of iron-catalyzed lipid peroxidation. U-78517F was found to have a 50% inhibitory concentration (IC50) of 0.6 microM against 200 microM ferrous chloride-initiated lipid peroxidation in rat brain homogenates, compared to 8 microM for U-74006F, 28 microM for alpha-tocopherol and 43 microM for the ring portion of alpha-tocopherol (i.e., trolox). Both stereoisomers of the racemic U-78517F proved to be equally active antioxidants. Against lipid peroxidation initiated by xanthine/xanthine oxidase, U-78517F was even more potent, with an IC50 of 0.01 microM. U-78517F was also observed to protect cultured mouse spinal neurons against iron-induced damage, with an IC50 of approximately 0.5 microM. When administered to male CF-1 mice i.v. at 5 min after a severe concussive head injury. U-78517F produced a dose-related improvement in the 1-hr neurological recovery. The minimum effective i.v. dose was 1.0 micrograms/kg. Measurement of U-78517 concentrations in the brains of mice after administration of a 10-mg/kg i.v. dose revealed effective antioxidant levels for as long as 2 hr. Evidence of an in vivo antioxidant action was provided by the attenuation of iron-induced blood-brain barrier disruption (i.e., Evans' blue extravasation) in rats pretreated with U-78517F.
5-HT2 receptor antagonists and migraine therapy. 5-Hydroxytryptamine (5-HT; serotonin) has been implicated in the pathophysiology of migraine, and several drugs with potent 5-HT2 receptor blocking activity (methysergide, pizotifen, cyproheptadine and mianserin) have been recognized as being clinically effective in migraine prophylaxis, although the selective 5-HT2 receptor antagonist ketanserin (the principal agent used to identify 5-HT2 receptor-mediated actions) seems to be ineffective in migraine. Pizotifen is the most widely used 5-HT2 receptor antagonist in migraine prophylaxis, because of its superior efficacy compared with cyproheptadine, and because the incidence and severity of adverse effects with pizotifen is lower compared with methysergide and mianserin. These agents have additional antagonistic effects at histamine H1, muscarinic cholinergic, alpha 1-adrenergic, alpha 2-adrenergic and dopamine receptors, but drugs which are selective for these non-5-HT receptors appear to be of no benefit in migraine. Actions mediated by 5-HT2 receptors which could be of relevance to migraine comprise cranial vasoconstriction, increased cranial capillary permeability and platelet aggregation, and some central nervous system effects and neuroendocrine functions. Although pizotifen, cyproheptadine and mianserin are considered to be relatively specific for 5-HT2 receptors, these agents and methysergide all share a high affinity for 5-HT1C binding sites; ketanserin, however, has little affinity for these sites, thus activation of 5-HT1C receptors may be an important step in the pathogenesis of migraine. It is not yet known which 5-HT1C receptor-mediated actions of 5-HT are relevant to migraine, but some behavioural actions and cranial vasodilatation via release of endothelium-derived relaxing factor may be involved.
Early gastric cancer: a clinicopathologic study. We report our experience, between 1973 and 1989 of 302 patients with gastric cancer in a Dutch general hospital. In 144 (47.7%) of them gastric resection was performed. Twenty-eight patients had early gastric cancer (EGC) (9.3% of the entire series and 19.4% of the resected specimens). Multicentricity of EGC was noted in 3 patients (10.7%). The incidence of EGC decreased slightly during consecutive 8-year intervals. There were 16 men and 12 women (mean age 64 and 66 years, respectively). Standard biphasic contrast radiographic studies of the upper gastrointestinal tract diagnosed or suggested malignancy in all but one patient. Endoscopy with directed biopsy diagnosed malignancy in all patients. Twenty-one lesions (67.7%) were localized to the antral region. Type IIc was most frequent (38.7%). There were 21 intestinal-type and 10 diffuse-type EGC by the Lauren classification. The incidence of intestinal-type EGC decreased during two consecutive 8-year periods. All type I and IIa lesions were of the intestinal type, whereas all diffuse-type EGCs were either type IIc or III. Lymph node metastasis was observed in 9.7% of the lesions. The incidence of lymph node metastasis increased from 0% in mucosal cancer to 20% in submucosal cancer. The overall 5-year survival rate was 91.3%: (diffuse type 100% and intestinal type 85.7%). The 5-year survival rate was 100% in mucosal cancer and 81.8% in submucosal cancer.
Radiation therapy as local treatment in Ewing's sarcoma. Results of the Cooperative Ewing's Sarcoma Studies CESS 81 and CESS 86. The Cooperative Ewing's Sarcoma Studies, CESS 81 and CESS 86, are multiinstitutional trials with more than 80 participating institutions from Germany, the Netherlands, Austria, and Switzerland. Treatment consists of four courses of multiagent chemotherapy and local therapy. Local therapy was not randomized and was either radical surgery or resection plus postoperative irradiation or definitive radiation therapy. Here results according to local therapy have been analyzed for 93 protocol patients with localized Ewing's sarcoma (ES) who have been recruited in CESS 81 from January 1981 to February 1985 and 122 protocol patients recruited in CESS 86 from January 1986 to November 1989. The 3-year relapse-free survival (RFS) was 55% in CESS 81 and 62% in CESS 86. In CESS 81, the RFS was better for surgically treated than for irradiated patients. In this study there was an extremely high incidence of local failures (50%) after definitive irradiation. In CESS 86, however, the results after radiation therapy have been improved markedly (3-year RFS 67% after radiation therapy, 65% after surgery, and 62% after resection plus irradiation). Possible explanations for the improvement of radiotherapeutic results are as follows: selections for patients for radiation therapy, start of local therapy, and quality of radiation therapy. In CESS 86, irradiated patients were randomized to receive either conventionally fractionated irradiation with less intense chemotherapy or hyperfractionated irradiation with simultaneous chemotherapy. There was no difference in treatment results at the time of analysis. The authors conclude that selection of patients for local treatment modalities and quality of treatment performance has an impact on local and overall treatment results in ES.
Myointimal hyperplasia as a result of balloon-catheter thromboembolectomy. The balloon-tipped embolectomy catheter is widely utilized in the treatment of arterial thromboemboli, significantly improving mortality and limb salvage rates. However, early and late complications related to catheter-tip injury and balloon trauma continue to occur and compromise the results of surgical intervention. Myointimal hyperplasia is an example of an unusual late complication induced by balloon-related arterial wall trauma. Myointimal hyperplasia is a commonly recognized healing response of the arterial wall to endothelial injury but is rarely reported after balloon-catheter thromboembolectomy. The extensive nature of the injury increases the incidence of limb loss. The pathophysiologic nature of this process is reviewed, and pertinent structural details such as intimal thickening and disruption of the internal elastic lamina are presented. The pathogenesis of myointimal hyperplasia suggests guidelines for catheter use during embolectomy that may further reduce the incidence of this unusual complication.
Effects of late administration of tissue-type plasminogen activator on left ventricular remodeling and function after myocardial infarction. To evaluate the effects of late thrombolysis on left ventricular volume and function in acute myocardial infarction, two-dimensional echocardiography and radionuclide angiography were performed before discharge and after 1 year of follow-up study in 34 patients with acute anterior myocardial infarction. Of these, 10 admitted to the coronary care unit within 4 h from the onset of symptoms were treated with recombinant tissue-type plasminogen activator (rt-PA) (Group A) and 24 admitted between 4 and 8 h after onset were randomly assigned to receive either rt-PA (Group B, n = 12) or conventional therapy (Group C, n = 12). Seven to 10 days after admission, all patients underwent cardiac catheterization and coronary angiography. Patency of the infarct-related vessel was 70% in Group A, 66% in Group B and 33% in Group C and the average Thrombolysis in Myocardial Infarction (TIMI) coronary perfusion grade was 1.9 +/- 0.8 for Group A, 1.6 +/- 1.0 for Group B and 0.84 +/- 0.95 for Group C (Group A versus Group C p less than 0.01; Group B versus Group C p less than 0.05). At predischarge evaluation, mean left ventricular end-systolic and end-diastolic volumes were higher in Group C than in Group B (p less than 0.001 and 0.05, respectively) and Group A (p less than 0.005 for both); mean left ventricular ejection fraction at rest was lower in Group C than in Group B and Group A (p less than 0.05 for both). At 1 year follow-up study, end-systolic and end-diastolic volumes remained higher in Group C than in Group B (p less than 0.05 for both) and Group A (p less than 0.005 for end-systolic volume and p less than 0.001 for end-diastolic volume); ejection fraction at rest was lower in Group C than in Groups A and B (p less than 0.05 for both); during exercise, it increased more in Group A than in Group C (p less than 0.01). Comparison of data obtained before discharge and at the 1 year follow-up study revealed a significant differences in end-systolic volume (p less than 0.05) in Group C patients and in end-diastolic volume in patients in Groups B (p less than 0.05) and C (p less than 0.001). The beneficial effect of late thrombolysis with rt-PA may be related to a reduction in myocardial expansion and thus to a favorable influence on postinfarction left ventricular remodeling.
Inflammatory pseudotumor in childhood. A diagnostic and therapeutic dilemma. We describe a case of inflammatory pseudotumor of the lower abdomen in a young child. The urinary bladder and abdominal wall were involved, and the pseudotumor simulated a malignant sarcomatous tumor. Surgical excision was undertaken, and the outcome was favorable. This rare tumor simulates a true neoplasm both clinically and morphologically and presents a diagnostic and therapeutic dilemma. Our case and a review of the literature indicate that an effort should be made to perform a radical excision. This is considered the treatment of choice except if it requires a mutilating procedure.
Late-infantile type galactosialidosis. Histopathology of the retina and optic nerve. We studied histopathologic findings from the retina and optic nerve of a patient with the late-infantile type of galactosialidosis and related them to clinical features of the condition. Markedly fewer ganglion cells were evident histopathologically using light microscopy. Results of histochemical studies demonstrated abnormal accumulation of lipid and proteinaceous material in the residual swollen ganglion cells. Marked loss of myelinated nerve fibers and thickening of the pial septum were also observed in the optic nerve. Both retinal ganglion cells and amacrine cells had intracytoplasmic inclusion bodies, but none were found in the optic nerve. These findings suggested that optic atrophy was induced by axonal wallerian degeneration secondary to retinal ganglion cell death. Although the fundus showed advanced optic nerve atrophy, a cherry red spot was not evident, possibly because of the marked decrease in ganglion cells in this case.
Alpha 1 blockers. Safe, effective treatment for hypertension. Alpha 1-adrenergic blocking agents, used alone or in combination with other medications, are efficacious in the management of hypertension. They are safe and well tolerated, and they offer unique advantages. Their mechanism of action in lowering blood pressure targets elevated peripheral vascular resistance, which is the principal hemodynamic abnormality of essential hypertension. The alpha 1 blockers maintain cardiac output and blood flow to vital organs, and they do not affect renin release. These agents have beneficial lipid and metabolic effects and can improve left ventricular hypertrophy, theoretically having a positive impact on cardiovascular morbidity and mortality. The only drug interaction identified with the alpha 1 blockers is an increased hypotensive effect when they are combined with other antihypertensive agents. A further advantage of the alpha 1 blockers is that, because of the widespread location of alpha 1 receptors, the agents offer potential benefit for a number of disease states, including benign prostatic hyperplasia. They also provide an especially useful antihypertensive choice for middle-aged and elderly patients.
Current status of imaging indeterminate renal masses. In 1986 Bosniak proposed a classification of cysts and cystic renal masses in an attempt to define precisely the radiologic findings for lesions not requiring further evaluation and for those that should be explored surgically in an attempt to salvage normal renal parenchyma. This classification has been extremely useful in expanding the number of patients treated conservatively. The following entities can be considered benign and require no further evaluation: the classic simple cyst (Bosniak category 1), a cyst with benign calcification (see Fig. 1A and B), a hyperdense cyst (see Fig. 2), and a cyst with thin (less than or equal to 1mm) septations (see Fig. 5A; Bosniak category 2). When any of the following features are present, further evaluation is warranted: aggressive calcifications (see Fig. 1C-E), abnormal density not fulfilling the criteria of a hyperdense cyst (see Figs. 3 and 4), or nodular septations (see Fig. 5B and C), or wall thickening (see Fig. 7; Bosniak) category 3). Small masses that cannot be characterized accurately also require further evaluation. Multiloculated masses(see Fig. 9) require surgery (Bosniak category 3). Most cases of multiple localized renal cysts can be distinguished from multiloculated masses and do not require surgery (see Fig. 10). Evaluation of cyst fluid by MR imaging has not been proved reliable in differentiating benign and malignant masses. MR imaging will become more useful when its spatial resolution equals that of CT. Masses that remain indeterminate after careful evaluation by ultrasonography and CT scanning can be evaluated additionally by angiography or cyst puncture. Management options for persistent enigmatic masses include follow-up radiologic studies, exploration, local excision, and nephrectomy.