123rc/medical_text huggingface dataset:
Elevated plasma aluminum levels in normal infants receiving antacids containing aluminum. Aluminum toxicity is a documented cause of encephalopathy, anemia, and osteomalacia. Excretion is primarily renal; therefore, patients with renal insufficiency are at risk for aluminum accumulation and toxicity. This has been demonstrated in uremic children treated with aluminum-containing antacids. The purpose of this study was to determine whether plasma aluminum levels were elevated in infants with normal renal function during prolonged aluminum-containing antacid use. Ten study infants (mean age = 5.8 months), who had been receiving antacids for at least 1 week, were compared with 16 control infants (mean age = 9.8 months) not receiving antacids. The study patients consumed 123 +/- 16 mg/kg per day (mean +/- SEM) of elemental aluminum for an average of 4.7 weeks. Their plasma aluminum level (37.2 +/- 7.13 micrograms/L) was significantly greater than that of the control group (4.13 +/- 0.66 micrograms/L) (P less than .005). It is concluded that plasma aluminum levels may become elevated in infants with normal renal function who are consuming high doses of aluminum-containing antacids. The safety of antacids containing aluminum should not be assumed and they should be used judiciously in infants, with careful monitoring of the aluminum dose and plasma level.
Plasma immunoreactive leukotriene C4 levels in patients with Kawasaki disease. The incidence of wheezing in Kawasaki disease (KD) has been investigated retrospectively. We measured plasma immunoreactive-leukotriene C4 (i-LTC4) levels of patients with KD. Wheezing was observed in 32 (12.5%) of the 256 patients with KD. Patients who had a prior history of bronchial asthma wheezed more frequently than other patients. During the acute stage of KD, plasma i-LTC4 levels both of wheezing and nonwheezing were significantly higher than those of healthy children. During the convalescent stage, plasma i-LTC4 levels of wheezing cases were higher than those of nonwheezing cases. We speculate that LTC4 contributes to the appearance of inflammatory symptoms during the acute stage of KD. During the convalescent stage when patients were taking aspirin, the presence of wheezing was associated with increased plasma levels of i-LTC4. More attention should be paid to the appearance of wheezing during the course of KD, especially in those cases in which the patient has a prior history of bronchial asthma.
Intraoperative detection of patent foramen ovale by transesophageal echocardiography. This study reports the intraoperative use of contrast and Doppler echocardiography techniques to diagnose patent foramen ovale (PFO). Fifty patients without known atrial septal defects undergoing elective cardiovascular surgery were studied. A 5-MHz esophageal echocardiographic probe was used to image the fossa ovalis (FO) and 10 ml agitated saline was injected into the right atrium during apnea. Echocardiographic contrast was then injected during end-inspiration at 20-cmH2O airway pressure. When opacification of the right atrium was complete, the airway pressure was released. During these maneuvers, color and pulsed-wave Doppler interrogation of the atrial septum were also performed. Right-to-left passage of saline contrast across the interatrial septum was seen in 11 of 50 patients (22%). Doppler echocardiography demonstrated a PFO in 2 patients without contrast evidence of shunting. Thus, the combination of contrast and Doppler echocardiography identified a 26% (13 of 50) prevalence of PFO, approximating the previously reported autopsy rate of 25%. These contrast and Doppler techniques may be useful in detecting patients at risk for paradoxical emboli and in identifying candidates for closure of the PFO.
Optic nerve gliomas and meningiomas. Optic nerve gliomas are benign astrocytic neoplasms that primarily affect children. The ultimate prognosis for vision is poor. For lesions confined to the optic nerves, long-term survival is excellent, but with involvement of the chiasm and especially of the hypothalamus or third ventricle, prognosis falls significantly. For this group, no form of therapy has proven to be of any benefit. Optic sheath meningiomas are neoplasms arising from arachnoid cap cells. They primarily affect middle-aged adults. Like gliomas, the prognosis for vision is poor, but unlike gliomas, prognosis for life is excellent.
Hypertension in African-Americans. A considerable disparity exists between African-Americans and US Caucasians in the incidence, severity, and management of hypertension. As a consequence, overall hypertension-related morbidity and mortality rates are at least threefold to fivefold higher in African-Americans than in Caucasians. Alarmingly high frequencies of stroke, end-stage renal disease, congestive heart failure, and left ventricular hypertrophy occur in African-Americans. To bring this crisis under control will require a renewed commitment to expanded research, improved public health measures, and more effective clinical intervention. Current hypertension control programs must be expanded and adequately funded. In addition, primary prevention of hypertension should be strongly recommended for the US population, especially African-Americans.
Spongiform encephalopathy transmitted experimentally from Creutzfeldt-Jakob and familial Gerstmann-Straussler-Scheinker diseases. A comparison was made of the effects of experimental intracerebral inoculation into marmosets of brain homogenates from a case of Creutzfeldt-Jakob disease (CJD) and from a member of the Wo. family with cerebral amyloid and spongiform encephalopathy--the Gerstmann-Straussler-Scheinker (GSS) syndrome. All the inoculated marmosets developed spongiform encephalopathy (SE) after incubation times of 20-23 months in the CJD group and 25-32 months in the GSS group. Subsequent passage from 1 affected animal in each group resulted in SE developing after 17 months incubation. In every animal inoculated with CJD or GSS material and in the 2 passage experiments the most severely affected region of the brain was the thalamus which in all cases was almost totally occupied by vacuoles. Other grey matter masses were less severely and less consistently affected. Vacuolation was observed in the cerebellar granule cell layer as well as in the molecular layer and the brain stem was finely vacuolated in all cases. There were only minor and inconsistent differences between the disease transmitted from CJD compared with GSS and some differences between the original transmissions and the SE caused by passaged inocula. Severe astrocytic gliosis accompanied the spongiform changes but no amyloid was identified in any of the marmosets with experimentally transmitted disease. The pathogenesis of the spongiform change in the thalamus was studied in a series of marmosets by light and electron microscopy 3-22 months after the intracerebral inoculation of CJD or GSS homogenates and was compared with controls. Dilated irregularly-shaped cisternae and the large complex vacuoles typical of SE, present in abundance after 18 and 22 months incubation, were considered most probably to be derived from cisternae of neuronal smooth endoplasmic reticulum.
Long-term follow-up review of 31 children with severe closed head trauma. Thirty-one children aged 3 to 15 years were followed for 5 to 11 years after suffering severe closed head trauma which caused coma for 1 week or more (median duration of coma 3 weeks). One patient remained in a persistent vegetative state until his death 9 years later. The other 30 recovered consciousness and were discharged. All suffered diminution of their abilities, and 24 of them had major permanent disability. The most common motor disabilities were pure spastic hemiparesis (seven cases), basal ganglia syndromes (four cases), ataxia (three cases), and a combination of hemiparesis and ataxia (five cases). Of the 30 patients, 26 regained independent ambulation, seven were epileptic, and 14 were dysarthric in various degrees. Only 10 had the cognitive ability to profit from the normal educational system, and none had attempted postsecondary education. Social problems were common. The worst outcomes were associated with intracranial bleeding and/or brain contusion seen on computerized tomography (CT) scans at the acute stage; the best were associated with normal CT scans. The degree of residual disability in these children seems no less than that of adults with trauma of similar severity.
Effects of vagal stimulation on experimentally induced seizures in rats. Repetitive stimulation of the vagus nerve inhibits chemically induced seizures in dogs. We report here the results and conclusions from studies designed to answer some of the immediate questions raised by this finding. (1) Maximal stimulation of vagal C fibers at frequencies greater than 4 Hz prevents or reduces chemically and electrically induced seizures in young male rats. (2) Antiepileptic potency is directly related to the fraction of vagal C fibers stimulated. (3) Vagal stimulation shortens but does not shut down a chemical seizure once it has begun. (4) In rats, optimal stimulus frequency is approximately 10-20 Hz; duration of stimulus, 0.5-1 ms; and stimulus strength, 0.2-0.5 mA/mm2 of nerve cross-section. These results, when taken together with similar results obtained from dogs, monkeys, and humans, strongly suggest that periodic stimulation of the vagus nerve using appropriate stimulation parameters is a powerful method for preventing seizures. The data from the literature suggest that the antiepileptic actions of vagal stimulation are largely mediated by widespread release of GABA and glycine in the brainstem and cerebral cortex. The probable pathway is via projections from the nucleus of the solitary tract to the reticular formation and thence by diffuse projections to the cortex and other areas. Intermittent vagal stimulation has the potentiality of reducing the number and/or the intensity of seizures in patients with intractable epilepsy. These results indicate that feasibility studies in humans should be continued and expanded.
Tricuspid valve papillary fibroelastoma: echocardiographic characterization. We report a tricuspid valve papillary fibroelastoma initially detected by transthoracic two-dimensional echocardiography and subsequently characterized by transesophageal two-dimensional echocardiography. The mass was excised during open heart operation, and the diagnosis was verified grossly and histopathologically. Transesophageal echocardiography usually provides images far superior to those from transthoracic echocardiography and may be a useful adjunct for intraoperative localization of intracardiac tumors for excision.
The value of the rectus abdominis myocutaneous flap in the treatment of complex perineal fistula. Complex perineal fistula and persistent perineal sinus are difficult to treat. We describe our experience with wide excision of the diseased perineum using a combined abdominoperineal approach. Ten patients were reconstructed by a rectus abdominis myocutaneous flap (n = 7), rectus abdominis muscle flap (n = 2), and omental graft (n = 1). Primary healing was achieved in all cases. A median follow-up of 18 months (range 6-54 months) has shown no recurrence of perineal disease or associated abdominal incisional hernia. There were no perioperative deaths. We propose that the rectus abdominis myocutaneous flap is indicated if large amounts of perineal skin has to be sacrificed. When less skin is removed a repair with greater omentum or rectus muscle alone is adequate. The abdominoperineal approach together with filling the residual pelvic cavity with well-vascularized tissue allows definitive treatment to be carried out in one stage.
Selective G to T mutations of p53 gene in hepatocellular carcinoma from southern Africa Hepatocellular carcinoma (HCC) is a prevalent cancer in sub-Saharan Africa and eastern Asia. Hepatitis B virus and aflatoxins are risk factors for HCC, but the molecular mechanism of human hepatocellular carcinogenesis is largely unknown. Abnormalities in the structure and expression of the tumour-suppressor gene p53 are frequent in HCC cell lines, and allelic losses from chromosome 17p have been found in HCCs from China and Japan. Here we report on allelic deletions from chromosome 17p and mutations of the p53 gene found in 50% of primary HCCs from southern Africa. Four of five mutations detected were G----T substitutions, with clustering at codon 249. This mutation specificity could reflect exposure to a specific carcinogen, one candidate being aflatoxin B1 (ref. 7), a food contaminant in Africa, which is both a mutagen that induces G to T substitution and a liver-specific carcinogen.
Are ioxaglate and iopamidol equally safe and well tolerated in cardiac angiography? A randomized, double-blind clinical study. A randomized, double-blind, parallel-group study was performed in 50 patients undergoing left ventriculography and coronary arteriography to evaluate ECG changes and the effects on left ventricular function of a low-osmolar ionic contrast agent, ioxaglate, as compared with a low-osmolar nonionic contrast medium, iopamidol. Twenty-five patients received ioxaglate (group 1) and 25 patients received iopamidol (group 2). All patients underwent 48 hours of continuous ECG recording beginning 24 hours before the cardiac catheterization. Left ventricular systolic and end-diastolic pressure, peak positive dp/dt, and dp/dt/P ratio were measured immediately before and after left ventriculography and 3 minutes later. Left ventricular systolic pressure did not change after injection of either contrast medium. Left ventricular end-diastolic pressure increased by 30% in group 1 (p less than 0.01) and by 22% in group 2 (p less than 0.01) immediately after left ventriculography. A further increase by 45% in group 1 (p less than 0.01) and by 24% in group 2 (p less than 0.01) was observed 3 minutes later. No differences were observed between values obtained in the two groups. Peak positive dp/dt did not change immediately after injection of either contrast medium but decreased by 5% (not significant) in group 1 and by 7% (p less than 0.02) in group 2 three minutes after left ventriculography. There were no significant differences between the two groups. Analysis of continuous 48-hour ECGs showed that both ioxaglate and iopamidol induced a slight increase (by 8% and 7%, respectively; p less than 0.05) in heart rate during injection with early and complete recovery.
Contrast venography in patients with very edematous feet: use of transdermal illumination to aid in vein puncture. Contrast venography can be technically difficult or impossible in patients with very edematous feet. The authors report a simple technique that uses transdermal illumination of the edematous subcutaneous tissue to enable visualization of a vein and also guide the needle into the vein. This technique has been used successfully in eight patients in whom conventional attempts at vein puncture had failed.
Channel specificity in antiarrhythmic drug action. Mechanism of potassium channel block and its role in suppressing and aggravating cardiac arrhythmias. Although work on class III antiarrhythmics remains at an early stage, these agents still appear to possess greater efficacy and less proarrhythmia than conventional class I agents in those experimental arrhythmia models considered to be most representative of the clinical situation. Although prolongation of repolarization carries with its own tendency for pause-dependent arrhythmogenesis (i.e., torsade de pointes), available data suggest that this may be a function of nonspecificity in potassium channel block rather than a general characteristic of class III activity. The availability of new and more selective blockers of specific cardiac potassium channels under development as class III agents have already helped to clarify basic questions about the ionic mechanism of repolarization in the heart, and one hopes that a growing clinical data base will eventually determine the relative safety and efficacy of these agents in preventing symptomatic and life-threatening arrhythmias.
Splicing defect at the ornithine aminotransferase (OAT) locus in gyrate atrophy. Gyrate atrophy (GA), a recessive eye disease involving progressive vision loss due to chorioretinal degeneration, is associated with the deficiency of the mitochondrial enzyme ornithine aminotransferase (OAT), with consequent hyperornithinemia. We and others have reported a number of missense mutations at the OAT locus which result in GA. Here we report a GA patient of Danish/Swedish ancestry in whom one OAT allele produces an mRNA that is missing a single 96-bp exon relative to the normal mRNA. Polymerase-chain-reaction amplification and sequencing revealed a 9-bp deletion covering the splice acceptor region of exon 5, resulting in the absence of exon 5 sequences from the mRNA with no disruption to the reading frame. This mutation, which was not present in 15 other independent GA patients, adds to the array of allelic heterogeneity observed in GA and represents the first example of a splicing mutation associated with this disorder.
Impaired polymorphonuclear leucocyte function in patients undergoing hepatectomy: adenylate energy charge and superoxide anion production in relation to hepatic mitochondrial redox state. Patients undergoing hepatectomy have an increased susceptibility to infection. We therefore studied the energy metabolism of the polymorphonuclear leucocyte (PMN), focusing on energy charge and function, especially superoxide anion (O2-) generation, in relation to the hepatic mitochondrial redox state. By labelling the PMN adenine nucleotide pool with radioactive adenine and by superoxide dismutase-inhibitable reduction of ferricytochrome c, the energy charge and O2- production was measured in 18 patients with hepatoma (non-cirrhotic, seven; cirrhotic, 11) undergoing hepatectomy. Their arterial ketone body ratios (KBRs), reflecting the hepatic mitochondrial redox potential, were above 0.7 before operation. After surgery, the 18 patients were divided into two groups: group A, KBR greater than 0.7, n = 10; and group B, KBR less than 0.7, n = 8. The energy charge and O2- release in group B decreased significantly from preoperative values (P less than 0.001 and P less than 0.01 respectively) and when compared with group A (P less than 0.05 and P less than 0.01 respectively). These results suggest that impaired hepatic energy metabolism (KBR less than 0.7) in hepatectomized patients leads to impaired energy charge and O2- production in the PMNs.
Utility of computed tomography for surveillance of small abdominal aortic aneurysms. Preliminary report. To assess the ability of computed tomography to predict the potential for expansion of small abdominal aortic aneurysms, we analyzed the computed tomographic scans of 30 patients who had two or more abdominal computed tomographic scans at least 6 months apart between 1979 and 1989. Clinical variables and 10 defined objective characteristics of computed tomography were evaluated. Twenty-five men and five women with abdominal aortic aneurysms ranging from 30 to 64 mm (mean, 45 mm) were followed up with serial computed tomographic scans for a mean (+/- SE) of 26 +/- 3 months. In 19 patients, enlargement of aneurysm diameter of 3 mm or more on serial computed tomographic scans was noted, whereas in 11, there was little or no expansion. Of the clinical variables studied, only serum cholesterol correlated with an increased risk of expansion. Thrombus area, measured by computed tomography, was 7.3 +/- 0.9 cm2 in enlarging aneurysms vs 4.3 +/- 0.9 cm2 in stable aneurysms. Based on these preliminary data, we conclude that computed tomography may provide valuable information about the likelihood of future expansion of small abdominal aortic aneurysms.
Primary biliary cirrhosis. Quantitation of autoantibodies to purified mitochondrial enzymes and correlation with disease progression. Primary biliary cirrhosis is characterized by the presence of antimitochondrial antibodies. Recently, six of the autoantigens have been identified as components of the 2-oxo acid dehydrogenase multienzyme complexes located within mammalian mitochondria. Immunoblotting studies have shown that two of these components, namely E2 and protein X of pyruvate dehydrogenase complex, are the major antigenic polypeptides recognized by autoantibodies. This study shows the development of an enzyme-linked immunosorbent assay to detect and quantitate antibodies to these two purified antigens. Coded serum samples from 166 patients with primary biliary cirrhosis, 140 patients with other liver and/or autoimmune disease, and 52 normal women were analyzed for reactivity using this immunoassay. These results indicate that this rapid, simple method has a 93% sensitivity and 96% specificity in the diagnosis of primary biliary cirrhosis. The titer of immunoglobulin G autoantibodies correlated not only with antimitochondrial antibody titer measured by indirect immunofluorescence (P less than 0.0001) but also with histological stage of disease (P less than 0.04) and prognostic biochemical variables such as higher serum bilirubin and lower serum albumin levels (P = 0.038 and 0.028, respectively). There was no significant correlation between titer of autoantibodies and serum globulin or immunoglobulin G levels, indicating that the positive correlation with disease progression was not secondary to hypergammaglobulinemia.
The relationship of "high risk" mammographic patterns to histological risk factors for development of cancer in the human breast. In the UK Trial for the Early Detection of Breast Cancer in Nottingham, 119 women were identified as having fibrocystic change with epithelial hyperplasia or in situ carcinoma. Their mammograms were classified according to Wolfe's criteria and the corresponding histology for each patient was classified for degrees of epithelial hyperplasia, atypia and in situ neoplasia using Page's criteria. A control population of patients presenting for breast screening was used to represent the general population. No correlation was found between the four mammographic Wolfe patterns, N1, P1, P2 and DY and histological evidence of epithelial hyperplasia, atypia or in situ carcinoma. A further study was carried out to determine histological features of Wolfe pattern, using radiological examination of resected breast tissue. The variation in Wolfe pattern was related to the distribution of fibrous and adipose tissue in the breast interlobular stroma and appeared to have no relationship to epithelial parenchymal content. This information does not support the hypothesis that radiographic densities of P2 and DY patterns correspond to high risk epithelial proliferation.