shukoor65/lab-rag-model huggingface dataset:
Mechanism of augmented left atrial pump function in myocardial infarction and essential hypertension evaluated by left atrial pressure-dimension relation. To analyze left atrial (LA) pump function in normal subjects, in patients with essential hypertension and in patients with a healed myocardial infarction, LA dimension (aortic-root echogram) and pressure (catheter-tip manometer) were simultaneously recorded in 25 patients (8 normal subjects, 7 with hypertension and 10 with myocardial infarction). The pressure-dimension relation of the left atrium was composed of 2 loops: the A loop (expressing the pump function of the left atrium) and the V loop. LA dimension at the beginning of active LA shortening was significantly greater in hypertensive subjects (33 +/- 3 mm) and in those with myocardial infarction (32 +/- 4 mm) than in normal subjects (28 +/- 3 mm) (p less than 0.01, p less than 0.05, respectively). The area of the A loop significantly increased in subjects with hypertension (48 +/- 3 mm Hg.mm, p less than 0.01) and in subjects with myocardial infarction (29 +/- 10 mm Hg.mm, p less than 0.05), compared with normal subjects (20 +/- 8 mm Hg.mm). The mean fractional shortening velocity of the left atrium significantly increased in subjects with hypertension, compared with normal subjects and those with myocardial infarction (p less than 0.05 for both). LA peak wall tension during the LA active contraction period significantly increased with hypertension and with myocardial infarction, compared with normal subjects (p less than 0.01, p less than 0.05, respectively). The area of the A loop was directly proportional to the LA dimension at the beginning of active LA shortening (r = 0.53), p less than 0.01).
Observation of spinal canal and cisternae with the newly developed small-diameter, flexible fiberscopes. Small-diameter (0.5-, 0.9-, and 1.4-mm) flexible fiberscopes were developed for visual diagnosis of spinal canal diseases. The fiberscopes were introduced via a Tuohy needle into the subarachnoid and epidural spaces of ten patients with various pain syndromes. Clear visualization of the subarachnoid space was achieved using the fiberscopes. The epidural space could be visualized only during withdrawal of the fiberscope. In five cases, the fiberscope could be advanced up to the level of the cisternae without causing the patient any discomfort. A slight headache and transient fever were noted after the examination in five and two cases, respectively, but no other complications occurred. Interestingly, preexisting pain diminished (two cases) or disappeared (one case) after the myeloscopy in three of five cases in which the myeloscopy revealed aseptic adhesive arachnoiditis. Further studies should be carried out to evaluate the usefulness of this technique.
Thickening at the root of the superior mesenteric artery on sonography: evidence of vascular involvement in patients with cancer of the pancreas. Thickening of the root of the superior mesenteric artery (SMA) was studied by using preoperative sonography in 23 patients with pancreatic cancer and in 10 healthy control subjects. Of the 23 with cancer, 11 had neoplastic involvement of the SMA and 12 did not. Prominent thickening of the area around the SMA with (six patients) or without (five patients) decreased echogenicity compared with the adjacent retropancreatic connective tissue was observed in patients with involvement of the SMA, a finding called the "cuff sign." Mean thickness of the periarterial area in the cancer patients with and without involvement of the SMA and in control subjects were 8.5 mm, 4.0 mm, and 2.9 mm, respectively. With an upper limit of normal of 7.0 mm for the thickness of the SMA, the sensitivity, specificity, and overall accuracy of this sign in the evaluation of involvement of the SMA were 91%, 100%, and 96%, respectively. Decreased echogenicity of the periarterial area was not observed in patients without involvement of the SMA or in control subjects. Our results show that sonographic evidence of periarterial thickening of the root of the SMA (cuff sign), especially with decreased echogenicity, is a reliable finding of tumor infiltration of the SMA in patients with pancreatic carcinoma.
Masseter muscle spasm in children: implications of continuing the triggering anesthetic. This retrospective study was undertaken to examine the management and outcome of children who developed isolated masseter muscle spasm (MMS) after the administration of intravenous succinylcholine during anesthetic induction. The inhalation anesthetics used for induction were continued in all of these cases. The medical records of 68 patients (male/female ratio, 1.7:1), identified from approximately 42,000 anesthetics given during the period 1980-1989, were reviewed. Fifty-seven children (2.3-12 yr old) were diagnosed as having isolated MMS, i.e., MMS without spasm of other muscles; 11 experienced generalized rigidity in combination with MMS. Anesthetic and postoperative management of these two groups differed. The overall incidence of MMS was 0.3% of inhalation anesthetics during which succinylcholine was given. Intraoperative arrhythmias occurred in 33% of the patients who developed isolated MMS and more frequently in older children. Most children experienced some degree of hypercarbia and/or metabolic acidosis, but the significance of these abnormalities in the spontaneously ventilating, fasting child is unknown. Serum creatine kinase levels when measured 18-24 h postoperatively were elevated in all but one child (n = 45). There was no long-term morbidity and no mortality. We conclude that failure of the masseter muscles to relax after succinylcholine is not uncommon in children. Based on our experience, and accepting that MMS may be part of the clinical spectrum of malignant hyperthermia, we believe that anesthesia can be continued safely in cases of isolated MMS when careful monitoring accompanies diagnostic evaluation. This differs from the current practice of discontinuing the anesthetic or switching to a nontriggering anesthetic technique.
Hemisphere asymmetry in decision making abilities. An experimental study in unilateral brain damage. Thirty control subjects and 60 unilateral brain-damaged patients, 30 with left hemisphere (LH) damage and 30 with right hemisphere (RH) disease, underwent a disjunctive 4-choice reaction time study. Speed of reaction (as defined by the reciprocal of reaction time (RT), movement time (MT) and total response time (TRT] and accuracy of response (as represented by the sum of errors in selecting the correct response key) were investigated comparatively as a function of side of lesion and of performance on Raven's Coloured Progressive Matrices (PM47). In contrast to movement speed (1/MT), reaction speed (1/RT) as well as total response speed (1/TRT) showed a lesion effect independent of side of damage. Conversely, accuracy was differentially impaired, LH damage being associated with a significantly higher number of errors. Speed and accuracy had different relationships with the performance on the PM47 in the two hemisphere groups. Speed was affected in parallel with changes in PM47 performance both in the LH and in RH groups, whereas accuracy was altered only in LH patients. It was concluded that speed of motor reaction is affected by unilateral brain lesions irrespective of their side, whereas decision making processes, as expressed by accuracy of response, seem to be specifically impaired by LH damage.
Cisplatin and etoposide as first-line chemotherapy for metastatic breast carcinoma: a prospective randomized trial of the Italian Oncology Group for Clinical Research. In this prospective randomized study, first-line treatment with the combination of cisplatin (P) and etoposide (E) was compared with the standard cyclophosphamide, methotrexate, and fluorouracil (CMF) combination in 140 patients. Complete remissions were obtained in 11% of 65 assessable patients on CMF and in 12% of 65 assessable patients on PE. Complete plus partial remission rates were 48% on CMF and 63% on PE (P = .08). Time to progression (median, 32 v 31 weeks), duration of response (48 v 39 weeks), and survival (75 v 76 weeks) were not different. Hematologic toxicity was significantly higher with PE, and gastrointestinal side effects were frequent with this treatment. This study demonstrated that the PE combination is effective as front-line chemotherapy. As far as response rate is concerned, a trend of superiority over CMF was observed, which was of borderline significance. Due to the lack of survival advantage and to toxicity, this combination is not recommended for routine clinical use. However, its high level of activity should be taken into account for further research.
Idiopathic colonic perforation in the neonate. We describe a premature infant in whom spontaneous perforation of the colon was initially detected on routine abdominal films. There was no clinical evidence of necrotizing enterocolitis, peritonitis, or bowel obstruction. Surgical and pathologic findings confirmed the diagnosis of idiopathic bowel perforation. Since spontaneous gastrointestinal perforation in the neonate is often difficult to diagnose clinically, radiographic evaluation may allow earlier diagnosis and prompt surgical treatment of this life-threatening condition.
Prognostic factors and complication rates for cervical cerclage: a review of 482 cases. Charts from 482 singleton pregnancies undergoing cerclage placement in patients over a 6-year period were reviewed. Cervical dilatation at time of surgery, number of previous spontaneous losses, and gestational age at placement were key determinants of outcome. The most frequent complication, premature rupture of the membranes, ultimately occurred in 38% of patients. The 6.6% infection rate was increased in patients undergoing emergent versus elective surgery (12.7% vs 4.7%, p less than 0.005) and in patients at increased dilatation at time of surgery (5.7% for less than or equal to 2 cm vs 41.7% for greater than 2 cm, p less than 0.005). McDonald and Shirodkar procedures had similar obstetric outcomes in patients undergoing their first cerclage. The subgroup of patients with prior cerclage surgery showed improved birth weight when the Shirodkar procedure was performed instead of the McDonald cerclage (mean birth weight 3020 vs 2470 gm, p less than 0.005). An increased rate of primary cesarean section was found in the Shirodkar group (31% vs 17%, p less than 0.005). Complication rates and pregnancy outcome appear to reflect cervical dilatation more than gestational age at time of surgery.
Extraspinal causes of lumbosacral radiculopathy. Twelve of 12,125 patients who had been referred during a seven-year period to a specialist in spinal disorders were found to have an extraspinal cause of radiculopathy or neuropathy of the lower extremity. The records of these twelve patients were reviewed retrospectively. The average age of the twelve patients was sixty-five years (range, forty-two to seventy-seven years). The cause of the symptoms was an occult malignant tumor in nine patients and a hematoma, an aneurysm of the obturator artery, or a neurilemoma of the sciatic nerve in the others. The average time from the onset of symptoms to the final diagnosis was eight months (range, one month to two years). The most useful test for determination of the correct diagnosis was computed tomography or magnetic resonance imaging of the abdomen and pelvis. Computed tomography or magnetic resonance imaging of the spine and bone-scanning of the whole body were of little help in localizing the disease. In four of the twelve patients, an operation was performed on the basis of an incorrect diagnosis. In dealing with elderly patients who have radiculopathy, one should be suspicious that the cause is outside the spine.
Hepatotoxicity of rifampin and isoniazid. Is it all drug-induced hepatitis? Serologic markers for hepatitis viruses were studied in 40 children who developed acute hepatitis during antituberculosis therapy with rifampin and isoniazid, with the aim of assessing the contributory role of these viruses toward producing hepatic injury. Hepatitis A and B were confirmed in 7.5 and 35% patients, respectively, by IgM antibodies. Epidemiologic evidence suggested the possibility of non-A, non-B hepatitis in at least a few of the remaining 23 children. Hepatitis B was seen more often in children with severe tubercular disease (72%) and was largely (92.8%) parenterally transmitted. The study highlights that the endemicity of viral hepatitis in developing countries, among other factors, could also be responsible for the reported higher incidence of hepatotoxicity from developing countries and also for the increased risk of hepatotoxicity seen in severe tubercular disease.
Hyperemesis gravidarum. A comparison of single and multiple admissions. Recurrent hyperemesis gravidarum is a frustrating and poorly studied complication of early pregnancy. Between 1979 and 1987, 140 women with emesis severe enough to require parenteral fluid and electrolyte replacement were admitted to the Medical University of South Carolina Hospital, Charleston, on 220 occasions. Thirty-nine of the 140 women were admitted on multiple occasions. A comparison of clinical characteristics of women with single and multiple admissions revealed no significant differences except that women admitted repeatedly for hyperemesis gravidarum were more likely to be nulliparous (P less than .05). Ptyalism (59% vs. 9%) and persistent vomiting for greater than 24 hours after admission (69% vs. 23%) were significantly more common among women who were admitted repeatedly (P less than .05). Despite published reports that hyperemesis gravidarum has no impact on ultimate perinatal outcome, this study indicated that women admitted repeatedly have a more severe nutritional disturbance, associated with significantly reduced maternal weight gain and neonatal birth weight. These risks argue for more aggressive antenatal treatment and increased fetal surveillance in pregnancies complicated by recurrent hyperemesis gravidarum.
Vancomycin added to empirical combination antibiotic therapy for fever in granulocytopenic cancer patients. European Organization for Research and Treatment of Cancer (EORTC) International Antimicrobial Therapy Cooperative Group and the National Cancer Institute of Canada-Clinical Trials Group [published erratum appears in J Infect Dis 1991 Oct;164(4):832] A total of 747 febrile granulocytopenic patients with cancer were randomized to receive ceftazidime plus amikacin (CA) with or without vancomycin (V) as initial empirical therapy. Single gram-positive bacteremias responded in 29 (43%) of 68 patients treated with CA and in 48 (72%) of 67 treated with CAV (P = .001). For single gram-negative bacteremias and clinically documented and possible infections the response rates of CA and CAV were 80% and 63% (P = .17), 55% and 75% (P = .009), and 74% and 81% (P = .16), respectively. However, for patients with gram-positive bacteremia and for all other patients, there were no differences by treatment regimens in the proportion of febrile patients on each trial day (P = .85, P = .82, respectively) or in the duration of fever (P = .22, P = .93, respectively). Moreover, no patient with gram-positive bacteremia died during the first 3 days of true empirical therapy. Antibiotic-associated nephrotoxicity was more frequent in patients treated with vancomycin (6% vs. 2%, P = .02). These results do not support the empirical addition of vancomycin to initial antibiotic therapy in cancer patients with fever and granulocytopenia.
The conversion of primaquine into primaquine-aldehyde, primaquine-alcohol, and carboxyprimaquine, a major plasma metabolite. Although efficacy and toxicity of primaquine (PQ) depend on bioconversion, the process is poorly understood, even for carboxyprimaquine (CPQ), the major plasma metabolite. Earlier work to clarify drug metabolism showed that PQ could be converted quantitatively into CPQ, in vitro, with human erythroleukemic K562 cells or nonleukemic bone marrow supplemented with calf serum. We have now found--using systems with serum only, as well as with K562, bone marrow, and adult or embryonic liver cells--that the bioconversion of the side chain of PQ involves a branched pathway with at least three separate enzymes and two derivatives other than CPQ. An oxidase activity in serum converted PQ first into a novel side chain aldehyde (Y). Aldehyde dehydrogenase transformed PQ-aldehyde into CPQ in cell-free systems and in K562, bone marrow, and adult liver cells. Embryonic hepatocytes or bone marrow treated with 1,3-bis(2-chloroethyl)-1-nitrosourea did not produce CPQ; instead, they made a metabolite (Xc) that we could synthetize via PQ-aldehyde and identify as PQ-alcohol. PQ-alcohol replaced CPQ as the final product whenever alcohol-dehydrogenase prevailed over aldehyde dehydrogenase. These enzymes operated in intact cells and controlled the biotransformation of PQ absolutely. Unless both dehydrogenase were absent, inhibited, or deprived of coenzyme, potentially cytotoxic PQ-aldehyde intermediate did not accumulate. Some of the unique tissues schizonticidal and gametocidal effects of PQ may depend on the distribution pattern and relative activities of PQ oxidase, aldehyde dehydrogenase, and alcohol dehydrogenase in human subjects and in parasites.
Inflammatory pseudotumor of the liver causing biliary obstruction. Treatment by biliary stenting with 5-year follow-up. Inflammatory pseudotumors of the liver are rare lesions that are becoming increasingly recognized, possibly because of frequent use of abdominal computed tomography (CT) and ultrasonography. Most previously reported cases have been treated by hepatic resection. For this reason, we describe a patient with obstructive jaundice secondary to an inflammatory hepatic pseudotumor in the porta hepatis. Bilateral internal biliary stents were inserted, and the patient remains well 5 years later. The clinicopathologic features of inflammatory pseudotumors of the liver are described, as are the implications of accurate diagnosis. There have been no previous reports of biliary stenting in management of inflammatory hepatic pseudotumors.
Syncope and orthostatic hypotension. PURPOSE: The purpose of this study was to determine the postural blood pressure response over time, the prevalence of orthostatic hypotension in patients with syncope, and the relationship of orthostatic hypotension to recurrence of symptoms. PATIENTS AND METHODS: We prospectively evaluated 223 patients with syncope in a standardized manner. Orthostatic responses were measured in a standardized fashion at 0, 1, 2, 3, 5, and 10 minutes or until symptoms occurred. Follow-up was obtained at 3-month intervals. Causes of syncope were assigned by predetermined criteria. RESULTS: Orthostatic hypotension (20 mm Hg or greater systolic blood pressure decline) was found in 69 patients (31%). The median time to reach minimal standing systolic blood pressure was 1 minute for all subjects. In patients with orthostatic hypotension (20 mm Hg or greater), mean time to reach minimum blood pressure was 2.4 minutes. The vast majority of patients with significant orthostatic hypotension had this finding within 2 minutes of standing. Orthostatic hypotension was common in patients for whom other probable causes of syncope were assigned. The recurrence of syncope was not related to the degree of orthostatic hypotension; however, the recurrence of dizziness and syncope as end-points was lower in patients with 20 mm Hg or greater systolic blood pressure reductions as compared with patients with lesser degrees of orthostatic blood pressure declines. CONCLUSION: Orthostatic hypotension is common in patients with syncope and is detected in the vast majority of patients by 2 minutes. Although symptom recurrence on follow-up was lower in patients with more severe orthostatic hypotension, the clinical significance of this finding needs to be further defined by future studies.
A meta-analysis of prophylactic antibiotics in head and neck surgery. Although it is generally agreed that prophylactic antibiotics are necessary for the prevention of postoperative wound infection, the choice of antibiotic regimen is controversial. In an attempt to determine the most effective antibiotic regimen, a meta-analysis of published clinical trials of prophylactic antibiotics for head and neck surgery was undertaken. The meta-analysis revealed a relative difference in infection rates of 43.7 percent in favor of the use of antibiotics versus placebo, of 8.3 percent in favor of multiple antibiotics versus a single antibiotic, of 13.7 percent in favor of multiple antibiotics versus cefazolin, and of 4.1 percent in favor of multiple-day prophylaxis versus single-day prophylaxis. This meta-analysis suggests that a 1-day course of clindamycin may be the most effective prophylactic antibiotic regimen for head and neck surgery.
Ossifying fibromyxoid tumor of soft parts. Additional observations of a distinctive soft tissue tumor. The author studied four subcutaneous soft tissue tumors, similar to those recently described by Enzinger and associates (Am J Surg Pathol 1989;13:817) by the name "ossifying fibromyxoid tumor," by immunohistochemistry and electron microscopy to further understand the cellular nature of this lesion. The four tumors were composed of uniform round cells often surrounded by a lacunar space. The tumors often contained a peripheral zone of metaplastic bone. The cellularity was high, but the mitotic rate was low, suggesting a benign or borderline nature of the lesion. Longer follow-up was available for three cases, showing recurrence-free survival times of 11, 8, and 3 years. Immunohistochemistry studies revealed that all tumors were strongly positive for S-100 protein and focally positive for Leu-7, whereas melanoma-specific marker HMB45 was negative. Vimentin was the main type of intermediate filament protein, and one case also contained scattered glial fibrillary acidic protein-positive cells. Epithelial markers (keratins, epithelial membrane antigen), desmin, and muscle actins were negative. Electron microscopic examination showed partial, sometimes reduplicated, basal lamina surrounding many cells. Complex cell processes were also present. No myofilaments were found. The immunohistochemical and electron microscopic results may suggest that this tumor has Schwann's cell differentiation.
Mucosal vascular stasis precedes loss of viability of endothelial cells in rat acetic acid colitis. The hypothesis that a significant reduction in colonic mucosal perfusion, and hence ischemic injury, precedes the development of mucosal ulceration and inflammation is tested in this report. The microcirculatory changes in the rat colonic mucosa within 1 hr of topical exposure to 10% acetic acid were assessed. Colonic mucosal blood flow signals measured by laser Doppler flowmetry were significantly reduced to 61 +/- 8, 52 +/- 10, and 37 +/- 13% (mean +/- SEM) of baseline values at 1 min, 4 min, and 10 min after the colonic mucosa was exposed to 10% acetic acid, respectively, but not in controls exposed to saline. After the start of application of 10% acetic acid (for 4 min), in vivo microscopy studies demonstrated that colonic mucosal ischemia (stasis of the red blood cells in the mucosal capillaries) occurred at 9 +/- 5 min (mean +/- SEM). Evidence of endothelial cell death (failure to exclude a fluorescent dye, propidium iodide, by endothelial cells) developed at 25 +/- 10 min (mean +/- SEM). These findings indicate that within minutes after contact of the colonic mucosa with 10% acetic acid, colonic mucosal ischemia develops, followed shortly by death of endothelial cells. The data do not establish a cause-and-effect relationship between the reductions in mucosal blood flow and loss of endothelial cell viability in response to acetic acid. Nevertheless, because these events occur at such an early time point, they may play a pathogenetic role in the development of the subsequent inflammatory and ulcerative changes in this animal model of colitis. Further studies to define the potential causal relationships between these parameters are warranted.