123rc/medical_text huggingface dataset:
Boron neutron capture therapy of intracerebral rat gliosarcomas. The efficacy of boron neutron capture therapy (BNCT) for the treatment of intracerebrally implanted rat gliosarcomas was tested. Preferential accumulation of 10B in tumors was achieved by continuous infusion of the sulfhydryl borane dimer, Na4(10)B24H22S2, at a rate of 45-50 micrograms of 10B per g of body weight per day from day 11 to day 14 after tumor initiation (day 0). This infusion schedule resulted in average blood 10B concentrations of 35 micrograms/ml in a group of 12 gliosarcoma-bearing rats and 45 micrograms/ml in a group of 10 similar gliosarcoma-bearing rats treated by BNCT. Estimated tumor 10B levels in these two groups were 26 and 34 micrograms/g, respectively. On day 14, boron-treated and non-boron-treated rats were exposed to 5.0 or 7.5 MW.min of radiation from the Brookhaven Medical Research Reactor that yielded thermal neutron fluences of approximately 2.0 x 10(12) or approximately 3.0 x 10(12) n/cm2, respectively, in the tumors. Untreated rats had a median postinitiation survival time of 21 days. Reactor radiation alone increased median postinitiation survival time to 26 (5.0 MW.min) or 28 (7.5 MW.min) days. The 12 rats that received 5 MW.min of BNCT had a median postinitiation survival time of 60 days. Two of these animals survived greater than 15 months. In the 7.5 MW.min group, the median survival time is not calculable since 6 of the 10 animals remain alive greater than 10 months after BNCT. The estimated radiation doses to tumors in the two BNCT groups were 14.2 and 25.6 Gy equivalents, respectively. Similar gliosarcoma-bearing rats treated with 15.0 or 22.5 Gy of 250-kilovolt peak x-rays had median survival times of only 26 or 31 days, respectively, after tumor initiation.
Percutaneous transluminal angioplasty of crural arteries. The authors dilated 103 stenosed crural arteries in 71 patients. Primary success was defined as traversing and reducing the lesion to a residual stenosis of less than 30%. This was achieved in 96% of cases. Complications included one vessel rupture and one occluding intimal flap, which were treated by the vascular surgeon with bypass and venous patch, respectively. One hematoma at the puncture site was treated surgically because of its size. With modern materials such as steerable guide wires and low-profile balloon catheters, dilation of crural arteries has become safe. Until now, the indications for percutaneous transluminal angioplasty (PTA) of crural arteries have been limited to Fontaine stages III and IV disease. The authors believe that the indications for PTA in Fontaine stage IIb disease are justified, especially if intervention improves outflow after a more proximal recanalizing procedure is performed.
Fine needle aspiration of pancreatic fluid collections. The complications of pancreatitis remain diagnostic and therapeutic challenges. Patients with simple pancreatitis, pancreatic necrosis, pseudocyst, noninfected fluid collection or abscess may all have similar clinical pictures. During the last decade computerized tomography (CT)-guided needle aspiration of peripancreatic fluid collections has been increasingly used as a diagnostic tool for pancreatic abscesses. This study reviewed the effectiveness of CT-guided needle aspiration of peripancreatic fluid collections at our institution in terms of diagnostic accuracy, correlation with eventual outcome, and safety. Charts of patients who underwent needle aspiration of de novo peripancreatic fluid collections over the past 2 years were reviewed. Thirty-five patients underwent 50 aspirations. Eleven patients (31%) had a positive aspirate culture; seven of these had a positive Gram's stain. There were no false positive Gram's stains but four false negatives. Twenty-four (69%) patients had negative aspirate Gram's stains and cultures. Patients with positive aspirate cultures were treated with antibiotics only (2), CT-guided drain placement (7), or surgical drainage (3). The mortality related to each of these therapeutic modalities was 50 per cent, 0 per cent, and 33 per cent, respectively. Of the 24 patients with negative aspirate cultures, five had no further treatment, 12 received antibiotics, and six underwent CT drain placement. All these patients survived. There was one false negative aspirate culture. This patient underwent delayed surgical drainage but expired. There were no major complications from CT-guided aspiration. CT-guided aspiration appears to be a safe and reliable method of diagnosing infection in peripancreatic fluid collections.
Ureterosigmoidostomy: long-term results, risk of carcinoma and etiological factors for carcinogenesis. We followed postoperatively 75 patients who underwent ureterosigmoidostomy between 1942 and 1987. Of the patients 30 were asked to undergo routine examination, including fiberoptic sigmoidoscopy with biopsy and analysis of a urine-feces slurry for nitrate, nitrite and nitrosamines in comparison to 20 control volunteers. After a mean observation of 14 years 7 months (1 to 46 years) 64.5% of the patients had bilaterally normal kidneys without any previous complications, 77.5% of the renal units being normal. Sigmoidoscopic biopsy revealed 3 carcinomas at the ureterocolonic junction resulting in an 8.5 to 10.5-fold increased risk of colon carcinoma compared to the general population. The excretion of nitrite and N-nitrosamines was increased, and nitrate excretion was decreased compared to healthy control volunteers, suggesting endogenous formation of nitrosamines by bacterially reduced nitrate and endogenous amines. The urological long-term results of ureterosigmoidostomy are similar to those of conduits. However, the increased incidence of colon carcinoma is not yet proved to be higher than in conduits.
Lower extremity revascularization via the lateral plantar artery. Lower extremity bypass grafts to the tibial and crural arteries are commonly employed to treat patients with atherosclerotic limb-threatening ischemia. Although occasional series have mentioned bypasses to a plantar artery, few of these specifically examine the results of arterial reconstructions using these vessels. Six patients underwent femoral to lateral plantar artery (LPA) bypass within a 19-month period for gangrene of the forefoot. There was one early graft failure and in the five completely autogenous reconstructions, graft patency and limb salvage had been achieved during a follow-up ranging from three to 22 months. The LPA is an acceptable site for anastomosis of lower extremity bypass grafts and the early results presented herein support its more liberal use when proximal sites are unavailable.
The diagnostic impact of prehospital 12-lead electrocardiography. STUDY HYPOTHESIS: It is feasible to apply prehospital 12-lead electrocardiography to most stable prehospital chest pain patients. Prehospital diagnostic accuracy is improved compared with single-lead telemetry. POPULATION: One-hundred sixty-six stable adult patients who sought paramedic evaluation for a chief complaint of nontraumatic chest pain. METHODS: One-hundred fifty-one prehospital 12-lead ECGs of diagnostic quality were obtained by paramedics on 166 adult patients presenting with nontraumatic chest pain. Paramedics and base station physicians were blinded to the information on acquired prehospital 12-lead ECGs and treated patients according to current standard of care-clinical diagnosis and single-lead telemetry. Final hospital diagnoses were classified into three groups: acute myocardial infarction (24); suspected angina or ischemia (61); and nonischemic chest pain (66). Paramedics and base station physicians' clinical diagnoses and prehospital and emergency department ECGs were similarly classified and compared. Prehospital and ED 12-lead ECGs were read retrospectively by two cardiologists. RESULTS: Paramedics achieved a high success rate (98.7%) in obtaining diagnostic quality prehospital 12-lead ECGs in 94.6% of eligible prehospital patients. For patients with acute myocardial infarction, prehospital ECG alone had significantly higher specificity than did the paramedic clinical diagnosis (99.2% vs 70.9%; P less than .001), and significantly higher positive predictive value (92.9% vs 32.7%; P less than .001). For patients with angina, combining the paramedic clinical diagnosis and the prehospital ECG significantly improved sensitivity (90.2% vs 62.3%; P less than .001) and increased negative predictive value (88.9% vs 71.3%; P less than .02) compared with paramedic clinical diagnosis alone. There was a high concordance between prehospital and ED ECG diagnosis (99.3% for acute myocardial infarction and 92.8% for angina). Furthermore, ten patients whose prehospital ECGs demonstrated ischemia and who had final hospital diagnoses of angina or acute myocardial infarction were mistriaged by paramedics and/or received no base station physician-directed therapy. CONCLUSION: It is feasible to apply prehospital 12-lead electrocardiography to most stable prehospital chest pain patients. Prehospital 12-lead ECGs have the potential to significantly increase the diagnostic accuracy in chest pain patients, approach congruity with ED 12-lead ECG diagnoses, and may allow for consideration of altering and improving prehospital and hospital-based management in this patient population.
Effects of diltiazem on complications and restenosis after coronary angioplasty. A randomized, placebo-controlled, double-blinded trial was performed to evaluate the usefulness of empiric therapy with a calcium antagonist in patients who undergo coronary angioplasty. A total of 201 patients were randomized to placebo or to high-dose diltiazem (mean dose, 329 mg/day). Treatment began 24 hours before angioplasty. Restenosis was assessed by percent area stenosis as determined by quantitative angiographic techniques before, immediately and 1 year after angioplasty. All patients also received aspirin and dipyridamole before angioplasty. Heparin and verapamil were administered intravenously during the procedure. The 2 groups were similar with respect to age, extent of coronary artery disease, smoking history, and baseline lipid levels. Procedural complications, including death (1 vs 1), Q-wave infarction (0 vs 3), acute occlusion (5 vs 5) and focal spasm (0 vs 0), were not significantly different in the diltiazem and placebo patients, respectively. Freedom from all acute complications was noted in 85% of patients in both groups. One-year angiographic follow-up was obtained in 60% of patients. Restenosis rates were similar: 36% in the diltiazem group and 32% in the placebo group (p = 0.30). The incidence of late cardiac events (death, Q-wave myocardial infarction, recurrent angina or coronary bypass graft surgery) was similar in the 2 groups. Thus, diltiazem did not influence the overall restenosis rate or prevent late events after coronary angioplasty.
Anticonvulsant and behavioral effects of two novel competitive N-methyl-D-aspartic acid receptor antagonists, CGP 37849 and CGP 39551, in the kindling model of epilepsy. Comparison with MK-801 and carbamazepine. The orally active competitive N-methyl-D-aspartate (NMDA) receptor antagonists CGP 37849 (DL-[E]-2-amino-4-methyl-5-phosphono-3-pentenoic acid) and its ethyl ester CGP 39551 were evaluated in amygdala-kindled rats, a model for complex partial and secondarily generalized seizures. Anticonvulsant and behavioral effects of these novel compounds were compared with those of the noncompetitive NMDA receptor antagonist MK-801 [(+)-5-methyl-10,11-dihydroxy-5H-dibenzo(a,d)cyclohepten-5,10-imin e] and the antiepileptic drug carbamazepine, one of the major drugs for treatment of partial and generalized seizures in humans. For comparative evaluation, the compounds were injected i.p. at the following doses: 1 to 10 mg/kg (CGP 37849 or CGP 39551), 0.05 to 0.3 mg/kg (MK-801) and 20 to 40 mg/kg (carbamazepine), respectively. In contrast to carbamazepine, CGP 37849, CGP 39551 and MK-801 exerted only weak anticonvulsant effects in fully kindled rats and did not increase the focal seizure threshold. The weak anticonvulsant effects of the NMDA receptor antagonists in kindled rats were associated with profound untoward behavioral effects. The behavioral syndrome induced by the NMDA receptor antagonists in kindled rats was characterized by marked ataxia, hyperactivity and, in case of CGP 37849 and MK-801, stereotypies, such as head weaving. The low or absent effectiveness of the novel NMDA receptor antagonists against kindled seizures suggests that these compounds will not be clinically useful antiepileptics against partial and secondarily generalized seizures. Furthermore, in view of the recent clinical findings on psychotomimetic effects of MK-801 in epileptic patients, the similarities in the excitatory effects produced by CGP 39551, CGP 37849 and MK-801 in kindled rats may indicate that competitive NMDA receptor antagonists may also produce psychotomimetic effects in humans.
Synthesis of type I collagen in healing wounds in humans. To quantify wound healing in surgical patients, samples of wound fluid were collected through a silicone rubber tube for 7 postoperative days and their concentrations of the carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP) were measured with specific radioimmunoassays. The mean concentration of PICP in would fluid on day 1 was 207 +/- 92 (SD) micrograms/L, and on day 2 908 +/- 469 micrograms/L (p less than 0.001, signed rank test). On day 7, the mean concentration reached was 380 times higher than that of day 1 (79,330 +/- 54,151 micrograms/L). Only one peak of PICP antigenicity, corresponding to the intact propeptide as set free during synthesis of type I procollagen, was detected on Sephacryl S-300 gel filtration analysis of wound fluid samples. The mean concentration of PIIINP was 70 +/- 61 micrograms/L on day 1, 86 +/- 88 micrograms/L on day 2, and 180 +/- 129 micrograms/L on day 3 (p less than 0.001 when compared with day 1). Finally on day 7, a 250-fold concentration (17,812 +/- 9839 micrograms/L), compared with day 1, was reached. Methods described in the present paper allow separate and repetitive quantification of the synthesis of both type I and type III procollagen during human wound healing.
Biliary cholesterol transport and precipitation: introduction and overview of conference. Cholesterol is secreted into bile as cholesterol-phospholipid vesicles. The cholesterol and phospholipid are subsequently exposed to the bile salts contained in the bile, which leads to the process of micellation. Two situations may arise depending on whether there is enough bile salt in proportion to cholesterol to complete this "maturation" process. If the cholesterol saturation is low, at equilibrium the bile salts will have completely micellized the vesicles. On the other hand, if bile is saturated with cholesterol, the micellation process is incomplete and vesicles and micelles will be present at equilibrium. The residual vesicle in this latter situation may have a higher cholesterol/phospholipid ratio because of the greater propensity of phospholipid to be micellized. This situation may result in cholesterol nucleation. The mechanism of nucleation from vesicles and the possible role of nucleating and antinucleating proteins in this process have been discussed.
Current concepts of cholesterol transport and crystal formation in human bile. The presence of vesicles in human bile probably accounts almost entirely for the frequently observed, but hitherto unexplained, phenomenon of metastable cholesterol supersaturation. This, in turn, largely explains the prolonged stability of cholesterol solubilized in supersaturated human bile. Under certain overall compositional conditions for a supersaturated native bile, the vesicular phase in its contribution to total cholesterol transport also becomes supersaturated in cholesterol. Because of this, the vesicles also become unstable, leading to formation of cholesterol crystals. A simple but common example of one factor affecting composition in this way is concentration of total solutes, especially the biliary lipids. Conversely, dilution of bile (e.g., hepatic bile) markedly reduces the cholesterol saturation level in biliary vesicles. The result is that such vesicles become much more stable. Under these conditions, cholesterol crystal formation becomes unlikely and rarely, if ever, occurs.
Intrapericardial pheochromocytoma. In a 34-year-old man with hypertension and increased urinary catecholamine excretion for 12 years, an m-[131I]iodobenzylguanidine scan and chest computed tomography located an intrapericardial pheochromocytoma in the left atrium. The tumor was excised through a left thoracotomy with cardiopulmonary bypass and circulatory arrest. At 34-month follow-up, blood pressure and urine catecholamine levels were normal. In the 15 cases of intrapericardial pheochromocytoma treated by resection reported in the literature, all 11 survivors were symptom-free except 1 who had residual left atrial tumor and multiple skeletal metastatic lesions. Computed tomography directed by the m-[131I]iodobenzylguanidine scan can be used for detailed location of the tumor. Appropriate surgical approach and use of cardiopulmonary bypass are critical in the resection of these highly vascular tumors.
Pheochromocytoma presenting as rhabdomyolysis and acute myoglobinuric renal failure. We report the case of a previously healthy young woman who presented with the sudden onset of rhabdomyolysis and myoglobinuric renal failure, requiring hemodialysis for 3 weeks. Common causes of rhabdomyolysis were ruled out; as renal function returned, severe hypertension was noted and a pheochromocytoma was diagnosed. We suggest that pheochromocytoma causes rhabdomyolysis and myoglobinuria via catecholamine-mediated vasoconstriction and skeletal muscle ischemia.
Family cancer syndrome: a study of the kindred of a man with osteogenic sarcoma of the mandible. Several familial cancer syndromes have been identified. The syndrome of sarcomas, breast cancer and other neoplasms, known as Li-Fraumeni syndrome, is characterized by several different neoplasms presenting at young ages with autosomal dominant transmission and a high incidence of second primaries. In this paper, we studied six generations (51 people) of the family of a 24-year-old man with osteogenic sarcoma of the mandible. Twelve malignancies in 11 people, including several rare tumors, were revealed. Mean age of presentation was 24 years old. Nine of the 11 patients died of disease. One developed a second primary. Two tumors presented in the head and neck. Transmission was autosomal dominant. The karyotypes of two family members were normal. Identification of Li-Fraumeni syndrome in a family is important in determining appropriate follow-up for the patient and family. Such families are models for studying carcinogenesis.
Arterial revascularization by laser angioplasty: first Italian experiences. Eighty-seven laser angioplasty procedures were performed on 85 patients (73 men and 12 women). In the first phase (54 patients) a broad selection process included long occlusions (23.9 cm avg) and vessels with heavy calcification; in the second phase (31 patients) the authors treated vessels with shorter occlusions (10 cm avg) and less calcific. The primary success rate, based on number of procedures (73.5% overall) was 69% in the first phase but reached 81.3% in the second phase. There were 14 perforations (16%), 8 dissections (9.4%), and 4 peripheral emboli (4.7%). Six-month follow-up shows that the Winsor index maintained its initial improvement in 76.5% of all patients, or 62% in just the long occlusions. These data and a review of the cases suggest that no more of 10-20% of patients with claudication in lower extremities can be treated by laser angioplasty; the authors consider ideal candidates those patients who noncalcific lesions in the common iliac or superficial femoral arteries at the III medium level with obstructions shorter than 8 cm and good runoff.
Would you recognize celiac axis syndrome? Since its original description, celiac axis syndrome has been a topic of debate. Clinical findings include postprandial abdominal pain, weight loss, and an epigastric bruit. Diagnosis is often made by exclusion and is confirmed by lateral aortography. The role of surgery in treating celiac axis syndrome is controversial.
Ischemic colitis. An ever-changing spectrum? Ischemic colitis, or more properly colonic ischemia, became a clear clinical entity in the past 25 years. Yet, early diagnosis of this disease with its various presentations remains a difficult task. A 10-year review at our hospital identified 38 patients with colonic ischemia for comparison with the authors' previous experience and with data from the literature. Several important factors emerge: (1) Twice as many cases occurred after operations (34% in this series vs. 16% in the past), probably because fewer and fewer spontaneous cases were hospitalized. (2) Sixteen patients required operative intervention for colonic ischemia with a mortality of 62 per cent, while those treated nonoperatively had a mortality of 14 per cent. Seven of eight postoperative patients who required a second operative procedure for their colonic ischemia died. A high clinical suspicion is necessary in the postoperative patient, as colonic ischemia appears to be more severe among these patients. Moreover, the high incidence of associated cardiovascular disease indicates that early diagnosis, as well as monitoring of the "at-risk" patient, is needed for improvement in survival to occur. New monitoring methods, such as tonometry, may help accomplish this goal.
Fourth branchial pouch anomaly. We present an extremely rare case of fourth branchial fistula in a 23-year-old male. The characteristic clinical feature was a recurrent left lower neck abscess which did not respond to appropriate medical and surgical therapy. Radiography and a computed tomographic scan with contrast material revealed a fistula running from the apex of the left pyriform sinus (internal opening) to the left lower neck abscess. The fistula tract was excised surgically. Histological examination of the excised fistula revealed a squamous epithelial lining and subepithelial lymphoid tissue. This pyriform sinus fistula is thought to be of fourth pharyngeal pouch origin, because of its surgical aspects and the histological findings of the excised fistula.