shukoor65/lab-rag-model huggingface dataset:
Dynamic tracking of cardiac vulnerability by complex demodulation of the T wave. A link is found between T wave alternans and vulnerability to ventricular fibrillation, and a new approach is provided for quantification of susceptibility to malignant arrhythmias. Complex demodulation reveals that alternation of the electrocardiogram is concentrated during the first half of the T wave, coinciding with the vulnerable period of the cardiac cycle. During myocardial ischemia and reperfusion, there are marked increases in the degree of T wave alternans that parallel the established time course of changes in vulnerability. The influence of the sympathetic nervous system in arrhythmogenesis is also accurately detected. Ultimately, complex demodulation of the electrocardiogram could provide a technique for identification and management of individuals at risk for sudden cardiac death.
Balloon dilation of postsurgical subaortic obstruction. Two children aged 10 and 5.5 years underwent balloon dilation for postsurgical subaortic obstruction. The outcome and the role of this procedure are discussed.
Post stenotic aneurysm in popliteal artery entrapment syndrome. In a retrospective review of 74 cases of Popliteal Entrapment Syndrome collected over a 16 year period, 10 cases of aneurysm were found (13.5%). This represents an incidence of 26% of the 38 cases of popliteal aneurysm of any etiology seen during the same period of time. In contrast to atherosclerotic aneurysms, these aneurysms were seen in a young age group (21-30 years of age) and all were associated with popliteal entrapment. Evidence is presented to support our opinion that these aneurysms are post-stenotic in origin. We feel that young adults with symptoms of leg ischaemia and evidence of an aneurysm of the popliteal artery should be investigated for popliteal entrapment and treated before complications occur. We have found a posterior approach to be the most satisfactory method of exploring the popliteal fossa.
A prospective study of liver function in infants and children exposed to daily isoflurane for several weeks. Eleven infants and children presenting for daily radiotherapy for a period of at least 2 weeks were anaesthetised with isoflurane in 33% oxygen and nitrous oxide. They were unpremedicated and given no other agents to supplement anaesthesia. The average number of exposures was 24 (SD 11; range 10-39) and the total anaesthetic time per exposure varied between 15 and 30 minutes. Liver function was assessed by determining serum total bilirubin, aspartate amino transferase, gamma glutamyl transferase and alkaline phosphatase before the start of treatment and at 5-daily intervals thereafter. There was no measurable change in any of these determinants of liver function. All children accepted daily induction of anaesthesia with isoflurane. Induction, maintenance and recovery from anaesthesia were uncomplicated.
FK 506 ameliorates the hepatic injury associated with ischemia and reperfusion in rats. The effect of FK 506 on regeneration of the liver was studied in rats after a two-thirds partial hepatectomy after 60 min of ischemia of the unresected liver. The animals were divided into three distinct groups of 10 rats each. Group 1 (controls) received 0.5 ml saline solution intravenously 30 min after the induction of ischemia. Groups 2 and 3 were injected with FK 506 (0.3 mg/kg) intravenously 30 min after and 24 min before the induction of hepatic ischemia, respectively. The hepatic content of ATP and serum levels of ALT and lactate dehydrogenase were determined on each animal. In addition, the histological appearance and mitotic activity of the remnant liver was determined at regular 24-hr intervals after hepatic ischemia. All 10 control animals died within 72 hr. Treatment with FK 506 resulted in improved survival in groups 2 and 3 (30% and 80%, respectively). The improved survival seen in the FK 506-treated animals was reflected by a restoration of hepatic ATP content, a reduction in the serum levels of ALT and lactate dehydrogenase, an amelioration of hepatic necrosis and neutrophilic infiltration and an increase in the mitotic activity of the liver. These results suggest that FK 506 ameliorates the hepatic injury associated with ischemia/reperfusion and has a potent stimulatory effect on liver cell regeneration that may make it valuable as a hepatoprotective agent when administered to organ donors before graft harvesting.
Synthesis of C1 inhibitor in fibroblasts from patients with type I and type II hereditary angioneurotic edema. Patients with hereditary angioneurotic edema (HANE) have serum levels of functionally active inhibitor of the first component of complement (C1 INH) between 5 and 30% of normal, instead of the 50% expected from the single normal allele. Increases in rates of catabolism have been documented in patients with HANE and certainly account for some of decrease in C1 INH level. A possible role for a decrease in synthesis of C1 INH in producing serum levels of C1 INH below the expected 50% of normal has not been well studied. We studied the synthesis of C1 INH in skin fibroblast lines, which produce easily detectable amounts of C1 INH. In type I HANE cells, C1 INH synthesis was 19.6 +/- 4.0% (mean +/- SD) of normal, much less than the 50% predicted. In type II HANE cells, the total amount of C1 INH synthesis (functional and dysfunctional) was 98.9 +/- 17% of normal; the functional protein comprised 43% of the total. Thus, type II HANE cells synthesized functional C1 INH at a much greater rate than for the type I cells. In both type I and II HANE cells, amounts of steady-state C1 INH mRNA levels paralleled rates of C1 INH synthesis, indicating that control of C1 INH synthesis occurred at pretranslational levels. Both type I and type II fibroblasts synthesized normal amounts of C1r and C1s. These data suggest that the lower than expected amounts of functionally active C1 INH in type I HANE may be due, in part, to a decrease in rate of synthesis of the protein, and that the expressions of the normal C1 INH allele in HANE is influenced by the type of abnormal allele present.
Orbital exenteration with eyelid sparing: indications, technique, and results. Of 22 orbital exenterations performed from January 1980 to December 1989, 16 were performed by an eyelid-sparing technique, and six were allowed to heal by spontaneous granulation. Reviewing these procedures, we conclude that the eyelid-sparing method is indicated mainly for advanced primary orbital malignancies and for certain secondary orbital malignancies such as orbital extension of uveal melanoma, conjunctival melanoma, and conjunctival squamous cell carcinoma. It is not usually applicable to orbital invasion of malignant eyelid tumors such as basal cell carcinoma and sebaceous gland carcinoma. Advantages of the eyelid-sparing method are more rapid healing and earlier fitting of a prosthesis.
Outcome of patients with acute myocardial infarction who are ineligible for thrombolytic therapy. OBJECTIVE: To determine what proportion of patients with acute myocardial infarction are not eligible for thrombolytic therapy and to assess their natural history. DESIGN: Retrospective chart review. SETTING: A large community-based hospital. PATIENTS: All patients with acute myocardial infarction hospitalized during a 27-month period. MEASUREMENTS: Of 1471 patients with acute myocardial infarction, 230 (16%) received thrombolytic therapy according to the protocol and an additional 97 (7%) received nonprotocol thrombolytic therapy, primary coronary balloon angioplasty, or both because of contraindications. The other 1144 patients (78%) did not receive reperfusion therapy. MAIN RESULTS: The patients who did not receive thrombolytic therapy were older, more likely to be women, and more likely to have a history of hypertension, previous myocardial infarction, or chronic angina (all comparisons, P less than 0.002). An average of 1.9 reasons for exclusion were identified per patient among the ineligible patients. Mortality was fivefold higher among ineligible patients (19%; Cl, 16% to 21%) than among protocol-treated patients (4%; Cl, 1% to 6%) (P less than 0.001). In-hospital mortality rates for excluded patients were 28% (Cl, 23% to 32%) in elderly patients (age, greater than 76 years; n = 396); 29% (Cl, 23% to 35%) in patients with stroke or bleeding risk (n = 209); 17% (Cl, 14% to 20%) in patients with delayed presentation (greater than 4 hours after the onset of chest pain; [n = 599]); 14% (Cl, 11% to 16%) in patients with an ineligible electrocardiogram (ECG) (n = 673); and 26% (Cl, 21% to 32%) in patients with a miscellaneous reason for exclusion (n = 243). Independent predictors of increased mortality were: age greater than 76 years, stroke or other bleeding risk, ineligible ECG, or the presence of two or more exclusion criteria. CONCLUSIONS: Thrombolytic therapy is currently used in the United States for only a minority of patients with acute myocardial infarction: those who have low-risk prognostic characteristics.
Patellofemoral pain caused by overactivity. A prospective study of risk factors in infantry recruits. A prospective study of 390 infantry recruits revealed that the medial tibial intercondylar distance and that the isometric strength of the quadriceps, tested at 85 degrees of flexion of the knee, had a statistically significant correlation with the incidence of patellofemoral pain caused by overactivity. Increased medial tibial intercondylar distance and increased strength of the quadriceps were therefore deemed to be risk factors for this syndrome.
Effect of intrathoracic pressure on plasma arginine vasopressin levels. Abdominal distention during pneumoperitoneum results in a marked increase in plasma arginine vasopressin levels, which has been ascribed to an increase in intrathoracic pressure. Because of this relationship, tense ascites could contribute to nonosmotic release of antidiuretic hormone, to the development of hyponatremia, and eventually to further ascites formation. The effect of pneumoperitoneum, thoracocentesis, and paracentesis on plasma arginine vasopressin levels was studied in three groups of patients, and the mechanism by which these maneuvers may induce these changes was investigated. Patients with pleural effusion, pneumothorax, or ascites showed a significant increase in plasma arginine vasopressin levels, and thoracocentesis or paracentesis resulted in a decrease in these levels. Plasma vasopressin levels increased significantly during pneumoperitoneum, as did intrathoracic and atrial pressures; the atrial transmural pressure gradient declined. However, no changes in plasma levels of norepinephrine, aldosterone, and renin activity were observed during pneumoperitoneum. Changes in plasma arginine vasopressin levels correlated with the changes in intrathoracic and atrial pressures and transmural pressure gradient. The authors conclude that increased intrathoracic pressure is associated with an increase in plasma arginine vasopressin levels and propose that ascites could be a factor promoting vasopressin release by acting on intrathoracic volume receptors in decompensated cirrhotics.
Toxic effects of cisplatin alone and in combination with gentamicin in stria vascularis of guinea pigs. The toxic effects on the stria vascularis of treatment with cisplatin alone and combined with the aminoglycoside antibiotic, gentamicin, were studied in guinea pigs. The toxicity induced in albino and pigmented guinea pigs was investigated morphologically with light and transmission electron microscopy, and functionally by brainstem-evoked response audiometry. The results of hearing thresholds were variable, ranging from no change in one ear in some of the animals to a hearing loss of 20 dB in one or both ears when treated with low-dose cisplatin alone or in combination with gentamicin. Bilateral deafness resulted from high-dose cisplatin combined with gentamicin. The combined treatment produced prominent structural damage in the stria vascularis. The results should be considered when aminoglycoside therapy is required in conjunction with cisplatin.
Malignant melanoma arising in a dermoid cyst of the ovary. Autopsy findings of primary malignant melanoma arising in an ovarian dermoid cyst in an 86-year-old woman are presented. The right ovary was replaced by a dermoid cyst, 14 x 9 x 9 cm in size, in which several nodular tumors with diameters less than 3.2 cm were localized. They comprised diffusely proliferating anaplastic cells with prominent nucleoli. Some of them contained melanin pigments in the cytoplasm. The tumor cells were positive for S-100 protein and ultrastructurally showed melanosomes. In addition, several benign pigmented lesions resembling dermal nevus, pigmented schwannoma, or cellular blue nevus were present in the dermoid cyst, one of which contained a malignant melanomatous component. Histologic transition between benign and malignant components and the presence of another small focus of atypical melanocytes in the benign lesion suggested that the malignant melanoma arose in close association with the previously existing benign pigmented lesions in the dermoid cyst.
Elective coronary artery bypass surgery without homologous blood transfusion. Early results with an inexpensive blood conservation program. Restriction of donor blood transfusions in cardiac surgery should reduce risks of infective contamination and antigenicity. We report a systemic, simple and inexpensive blood conservation program used for 121 consecutive patients who underwent elective coronary artery bypass surgery without need for homologous blood transfusion. The left internal mammary artery was grafted in all cases, in addition to saphenous vein grafts. Autologous, heparinized blood was removed intraoperatively, pre-bypass, and returned to the patient at conclusion of the extracorporeal circulation. The volume remaining in the oxygenator and the tubing set was returned without cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the heart-lung machine, autotransfusion of the shed mediastinal blood was continued hourly up to 18 hours after surgery. The mean postoperative mediastinal bleeding was 551 +/- 206 ml, of which 505 +/- 218 ml was autotransfused. No re-exploration for bleeding was required and no homologous red-cell transfusions were given. Five patients each received 1-2 units of fresh frozen plasma because of prolonged bleeding time. Morbidity was low and mortality nil. At discharge the mean hemoglobin was 12.0 +/- 1.4 g/dl and the hematocrit 36.0 +/- 4.2%.
Insect paralysis by baculovirus-mediated expression of a mite neurotoxin gene. Female mites of the species Pyemotes tritici inject an extremely potent venom into their insect prey that causes muscle-contraction and paralysis. These mites are able to paralyse insects 150,000 times their size and their venom is effective in a broad range of insect species. A toxin (TxP-I) associated with the mite venom apparatus causes immediate muscle-contractive paralysis when injected into insects but not mice. In this report, we describe the cloning, sequencing and expression of a complementary DNA (Tox-34) encoding TxP-I. Insect cells infected with a recombinant baculovirus (vEV-Tox34) expressing Tox-34 secrete three polypeptides related to TxP-I which cause paralysis on injection. Larvae infected with vEV-Tox34 become paralysed during infection, thus reflecting the potential application of this toxin gene in insect biocontrol methods. The toxin gene expression system will also allow further exploration of the neurophysiological basis of its insect-specific effects.
Vogt-Koyanagi-Harada syndrome. Clinical course, therapy, and long-term visual outcome. We reviewed data from 26 patients with Vogt-Koyanagi-Harada syndrome who presented at the Bascom Palmer Eye Institute between March 1969 and February 1990. Visual outcomes were good, with final visual acuity of better than 20/30 in 29 (66%) of 44 eyes and of worse than 20/400 in only three (7%) of 44 eyes. A poor prognosis was associated with the development of choroidal neovascular membranes or chronic uveitis. All patients were treated with systemic corticosteroids. Corticosteroid therapy averaged 6 months, but was prolonged (48 months) in patients who developed chronic uveitis. Disease recurred in nine (43%) of 21 patients in the first 3 months, usually in association with a rapid tapering of steroid dosage. We recommend the early, aggressive use of systemic corticosteroids in patients with Vogt-Koyanagi-Harada syndrome and a gradual tapering of drug dosage for 6 months after presentation.
Splenosis presenting as a left renal mass indistinguishable from renal cell carcinoma. Splenosis following splenic trauma is a common but underdiagnosed entity before surgical exploration. In all previously reported cases the ectopic splenic tissue was distinctly separate from the kidney. To our knowledge we report the first known case in which the splenic tissue was located in direct apposition with the kidney. Using conventional imaging techniques, including renal ultrasonography, abdominal computerized tomography and selective renal arteriography, this ectopic splenic tissue appeared to be part of the left kidney and was indistinguishable from renal cell carcinoma. The pathophysiology, clinical presentation and diagnostic studies of splenosis are reviewed.
Metabolic consequences of (regional) total pancreatectomy. Little information has been reported on the metabolic characteristics of the totally pancreatectomized patient or the efficacy of medical management after radical pancreatic surgery. The prospective evaluation of 49 such patients, with 31% followed for 48 or more months, forms the basis of this report. The major immediate postoperative challenge is control of diarrhea and weight stabilization. Chronically patients have an increased daily caloric requirement (mean +/- SE, 56 +/- 1 kcal/kg), not wholly explained by moderate steatorrhea (fecal fat excretion, 16% +/- 2% of unrestricted fat intake). Despite persistent malabsorption, deficiencies in fat-soluble vitamin, magnesium, and trace element serum levels can be prevented in most patients. Pancreatogenic diabetes is characterized by (1) absence of the major glucoregulatory hormones insulin and glucagon, (2) instability, and (3) frequent hypoglycemia, with the latter parameters improving with rigorous home glucose monitoring. No patient has developed clinically overt diabetic micro- or macrovascular disease. Performance status in long-term survivors has been reasonable. However adverse chronic sequelae of the operation occur and include an unusual frequency of liver disease, characterized by accelerated fatty infiltration, and osteopenia, with an 18% reduction in radial bone mineral content noted in pancreatectomized patients studied more than 5 years after surgery.
Correlation of nuclear morphometry and DNA ploidy in rectal cancer. Several investigators have used morphometric measurements to determine differences in the nuclear size and shape of normal and neoplastic colorectal tissue. Changes in nuclear morphometric parameters have also been shown to correlate with prognosis in a variety of noncolorectal cancers. The association of nuclear morphometry with prognostic indicators in rectal cancer has not been well studied. Measurements of the nuclear area, perimeter, longest cord, and circularity factor from 39 primary rectal adenocarcinomas were compared with DNA content, degree of tumor differentiation, Dukes' class, and patient survival. Nuclear circularity was found to correlate with DNA ploidy. Nondiploid tumors with a DNA index greater than 1.3 had significantly more circular nuclei than tumors with diploid or near-diploid DNA content. There was no correlation between nuclear morphometry and Dukes' class or patient survival. Significant increases in DNA content of rectal cancers appear to be reflected by measurable changes in nuclear shape. Nuclear morphometric measurements may provide useful information in the study of the progression of neoplastic changes in colorectal cancer.
Chondrosarcoma of the parapharyngeal space. Chondrosarcoma is rarely found arising in the head and neck region. An unusual case arising in the parapharyngeal space in a male is reported and the differential diagnosis, pathology and treatment are discussed.
Coronary angioplasty in single-vessel complex lesions: short- and long-term outcome and factors predicting acute coronary occlusion. Percutaneous transluminal coronary angioplasty (PTCA) of complex coronary lesions (plaque ulceration and/or thrombus) has an increased risk of procedural complications. To assess the influence of these angiographic features on immediate and long-term results of PTCA, we prospectively compared the success rate, incidence of procedural complications, and restenosis rate in two groups of patients selected on the basis of the presence (study group = 30 patients) or absence (control group = 200 patients) of complex morphology at the time of angioplasty. The two groups were similar with regard to extent of coronary artery disease and site of coronary stenosis. Patients in the study group had a higher incidence of periprocedural acute coronary occlusion (47% vs 6%; p less than 0.01), which in 78% of the cases was successfully treated with repeat angioplasty and intracoronary thrombolysis. Univariate correlates of this complication were Canadian Cardiovascular Society class IV (57% vs 19%; p less than 0.05) and recent (less than 30 days) onset of worsening of symptoms (71% vs 31%; p less than 0.05). The incidence of acute myocardial infarction was slightly higher in the study group (6.7% vs 2%; p = NS), and the success rate with redilatation was the same (90%). Clinical and angiographic follow-up data were obtained from all patients in whom the procedure was successful; the restenosis rate was 55% in the study group compared with 36% in the control group (p less than 0.05).
Intravascular ultrasound imaging of human coronary arteries after percutaneous transluminal angioplasty: morphologic and quantitative assessment. An intravascular ultrasound catheter system was used in patients to assess the effect of percutaneous transluminal coronary angioplasty. In 14 out of 16 patients, the intravascular ultrasound catheter could be successfully advanced to the site of a previous dilatation. Qualitative assessment of the cross-sectional images revealed intimal thickening and an increase of ultrasound reflectance and calcification at atherosclerotic coronary arteries. A disruption of the obstructing plaque and evidence for local dissections (11 of 14 cases) were observed after angioplasty. The quantitative comparison between angiography and the ultrasound measurement showed a close correlation for vessel sites distant to the dilatation (r = 0.91 for vessel diameter; r = 0.86 for luminal area; p less than 0.001). After angioplasty, the quantitative evaluation of the dilated area was possible in 11 cases. The correlation of angiographic and sonographic measurements of these segments was good for the assessment of the vessel diameter (r = 0.82, p less than 0.001), but poor for the determination of the luminal area (r = 0.48, p = 0.10). This difference reflected the complex morphology of the vessel lumen after angioplasty, which would be better assessed by the cross-sectional sonographic technique than by contrast angiography. The intravascular imaging of coronary arteries provides a new and unique method to obtain information on the plaque morphology and composition, and to assess the local effects of interventional procedures and their complications.