shukoor65/lab-rag-model huggingface dataset:
Peptic ulcer disease in children. Primary duodenal ulcer disease occurs in children of all ages, but is most often seen in those over 10 years. As in the adult, it often pursues a chronic course. Primary gastric ulcer is seen in children under 6 years, is more unusual, and does not tend to recur. Stress ulcers are seen most often in infants and in critically ill children and are asymptomatic until the complications of hemorrhage or perforation appear. Drug-related ulcers are being seen more frequently as the use of nonsteroidal anti-inflammatory agents increases. With the use of new therapeutic agents, management has been simplified and surgical intervention has become a rarity. Helicobacter pylori is now a recognized cause of antral gastritis and ulceration in the child.
Formation of noninfectious HIV-1 virus particles lacking a full-length envelope protein. Deletions were constructed within a functional human immunodeficiency virus type 1 (HIV-1) proviral clone in order to assess the role of the envelope protein in virus particle formation. A graded exonuclease deletion technique was used to produce 12 clones with deletions of 175-308 nucleotides in the first conserved domain of envelope. This included 9 clones with frameshift deletions and 3 clones with in-frame deletions. Isogenic pairs of env deletion clones were produced with or without an additional deletion in the vif and vpr genes. Upon transfection, all clones produced virus particles, as determined by p24 antigen, reverse transcriptase, and sucrose gradient assays with conditioned media. Virus particles produced from clones with deletions in env or vif and vpr, or both regions, banded on sucrose gradients with a mobility similar to that of virus produced by the parental clone. The p24 gag capsid protein in the particles was resistant to trypsin, but the particles were disrupted by treatment with Triton X-100, suggesting the presence of a surrounding lipid bilayer. Furthermore, electron microscopic studies revealed both mature and immature virus particles derived from COS cells transfected with the env deletion clones. Cocultivation experiments with lymphoid cells and cells transfected with each of the env deletion clones demonstrated that the virus particles were noninfectious.
Ribose facilitates thallium-201 redistribution in patients with coronary artery disease To investigate whether i.v. infusion of ribose, an adenine nucleotide precursor, postischemia facilitates thallium-201 (201Tl) redistribution and improves identification of ischemic myocardium in patients with coronary artery disease (CAD), 17 patients underwent two exercise 201Tl stress tests, performed 1-2 wk apart. After immediate postexercise planar imaging, patients received either i.v. ribose (3.3 mg/kg/min x 30 min) or saline as a control. Additional imaging was performed 1 and 4 hr postexercise. Reversible defects were identified by count-profile analysis. Significantly more (nearly twice as many) reversible 201Tl defects were identified on the post-ribose images compared to the post-saline (control) images at both 1 and 4 hr postexercise (p less than 0.001). Quantitative analyses of the coronary arteriogram was available in 13 patients and confirmed that the additional reversible defects were in myocardial regions supplied by stenosed arteries. We conclude that ribose appears to facilitate 201Tl redistribution in patients with CAD and enhances identification of ischemic myocardium.
Gastric emptying and interdigestive antroduodenal motility in patients with esophageal scleroderma. The study was carried out on two groups of patients with esophageal scleroderma (LES pressure less than 5 mm Hg and amplitude of smooth muscle pressure waves less than 10 mm Hg): one group included patients with mild (group M) and the other severe (group S) gastroesophageal reflux (GER) diagnosed by ambulatory esophageal pH monitoring. Nine normal subjects were used as controls. Antroduodenal motility was recorded by means of manometry for 200-300 min after an overnight fast and the gastric emptying (T1/2) of a semisolid meal was measured utilizing a scintigraphic method. Patients of group S showed a significantly lower incidence of migrating motor complex activity fronts, as well as a more delayed gastric emptying, compared with those of group M. The reason that patients with the same degree of esophageal motor impairment have different degrees of GER may lie in the fact that the concomitant impairment of gastrointestinal interdigestive cyclic clearing activity and the delay in gastric emptying may allow a larger quantity of material to remain stagnant in the gastric lumen, readily available for gastroesophageal reflux.
Impaired diastolic function and coronary reserve in genetic hypertension. Role of interstitial fibrosis and medial thickening of intramyocardial coronary arteries. Left ventricular hypertrophy (LVH) in rats with genetic hypertension is accompanied by abnormal myocardial diastolic stiffness and impaired coronary reserve. Whether these functional defects are related to a structural remodeling of the myocardium that includes an interstitial and perivascular fibrosis, myocyte hypertrophy, and medial thickening of intramyocardial coronary arteries is uncertain. To address these issues, 14-week-old male spontaneously hypertensive rats with established hypertension and LVH were treated with low-dose (SLO group: 2.5 mg/kg/day, n = 11) or high-dose (SHI group: 20 mg/kg/day, n = 9) oral lisinopril for 12 weeks to sustain hypertension and LVH or to normalize arterial pressure and myocardial mass, respectively. When SHI and SLO groups were compared with age- and sex-matched 26-week-old untreated spontaneously hypertensive rats (n = 11) and normotensive Wistar-Kyoto rats (n = 9), we found 1) normalization of blood pressure (p less than 0.005) and complete regression of LVH (p less than 0.005) in the SHI group and no significant blood pressure or LVH reduction in the SLO group, 2) complete regression of morphometrically determined myocardial interstitial and perivascular fibrosis in SHI and SLO groups (p less than 0.025) associated with normalization of diastolic stiffness, measured in the isolated heart (p less than 0.025), and 3) regression of medial wall thickening of intramyocardial coronary arteries only in the SHI group (P less than 0.005), accompanied by a normalization of coronary vasodilator reserve to adenosine (p less than 0.005). Thus, interstitial fibrosis and not LVH is responsible for abnormal myocardial diastolic stiffness, whereas medical wall thickening of intramyocardial resistance vessels, influenced by arterial pressure, is associated with impaired coronary reserve.
Time course of the blood pressure response to oral isradipine in uncomplicated mild-to-moderate essential hypertension. Forty-five patients with supine diastolic blood pressures (DBPs) above 95 mm Hg at the end of a four-week placebo run-in period were randomized to receive either 1.25 mg, 2.5 mg, or 5 mg isradipine twice daily as monotherapy for 12 weeks. Blood pressures (BP) were measured every 14 days, always by the same observer and using standard techniques. The Montevideo Mathematical Model was used to determine the time course of the response to treatment in each dosage group. Of the 33 patients who completed the study, four of the 12 patients receiving 1.25 mg isradipine twice daily had their BP controlled by weeks 10 or 12 (supine DBP less than or equal to 90 mm Hg), seven of 11 by 2.5 mg twice daily, and five of 10 by 5 mg twice daily. Mean DBPs for each dosage group were significantly reduced by week 12 (P less than .015 in all groups). The Montevideo Model allows estimation of the time after onset of treatment by which BP is reduced by a given amount. This model indicated that, with 2.5 mg isradipine twice daily, a fall in mean arterial pressure of 10 mm Hg is to be expected within three weeks of initiating drug administration.
Clinical studies of sucralfate in reflux esophagitis. The European experience. Reflux esophagitis is encountered quite frequently in clinical practice. Symptoms can be mild, moderate, or severe and complications can occur, particularly if the disorder is untreated or undertreated. Treatment is aimed at relieving symptoms, healing lesions, and preventing complications. Various pharmacologic options are available for treatment, including antacids, alginate/antacid compounds, acid-reducing agents, prokinetic drugs, and agents that protect the mucosa. This article reviews a number of clinical studies evaluating sucralfate in the treatment of reflux esophagitis. Almost all of the investigations were conducted in Europe and encompassed open-label studies, placebo-controlled trials, and comparative studies. From the studies discussed, it can be concluded that sucralfate not only has a place in the treatment of peptic ulcer disease, but is also effective in treating reflux esophagitis. Sucralfate is comparable to H2-receptor antagonists in symptom improvement and healing rates. In addition, the studies reviewed have shown sucralfate to be safe and well tolerated.
Accumulation of glycoprotein in the Golgi apparatus of hepatocytes in alcoholic liver injuries. To clarify the role of the hepatocytic Golgi apparatus in the accumulation of proteins in the hepatocytes of alcoholic liver disease, changes in the Golgi apparatus in human and experimental alcoholic liver injuries were analyzed. Immunoelectron microscopically, transferrin, one of the secretory glycoproteins from the liver, was retained in the smooth endoplasmic reticulum and Golgi apparatus of the hepatocytes in both human and rat alcoholic liver injuries. Biochemically, transferrin content in the Golgi fraction was clearly high in the rats with alcoholic liver injury. Desialo-glycoproteins were found in the serum of rats with alcoholic liver injuries. These results suggested that the glycosylation and secretion of hepatic glycoproteins in the Golgi apparatus were impaired in alcoholic liver injury. These abnormalities in the Golgi apparatus function may be important for the development of alcoholic liver injury.
The prognostic significance of postoperative residual tumor in ependymoma. Between 1970 and 1989, 29 patients with intracranial ependymomas were evaluated and treated at the Children's Hospital in Boston. With a median follow-up of 82 months, the actuarial survival rates at 5 and 10 years were 61 +/- 10% and 46 +/- 12%, respectively. Anaplastic histological findings were uncommon (2 of 29). Initial postoperative radiotherapy was given to 25 patients, with a median tumor dose of 5360 cGy. With a median time to recurrence of 22 months, local failure (within 2 cm of original enhancing mass) was the predominant pattern of relapse (15 of 16 failures). The presence of radiographic residual disease seen on postoperative magnetic resonance imaging or computed tomographic scans was the most important prognostic variable for patients with intracranial ependymoma. Analysis of the 19 patients who underwent postoperative imaging revealed a 75 +/- 15% 5-year freedom from progressive disease for 9 patients with no residual disease, as compared with 0% freedom from progressive disease for the 10 patients with gross residual disease (P = 0.03). In contrast, the surgical assessment of residual disease was not significant (P = 0.4). Age at presentation was also a significant prognostic factor. The overall actuarial survival rate at 12 years for infants 24 months or younger at diagnosis was 0%, as compared with 62 +/- 13% for older patients (P = 0.03). For non-anaplastic ependymomas, complete surgical resection followed by local-field, high-dose (greater than 54 Gy) radiotherapy appears to offer the greatest chance for long-term survival. Because of the markedly reduced survival rate for patients with radiologically apparent postoperative disease, maximal surgical resection and novel therapeutic endeavors appear warranted for this high-risk group. Future protocols should use postoperative imaging, not operative reports, to stratify patients with ependymoma.
The course of peptic ulcer disease. Peptic ulcer disease usually has periodic exacerbations and remissions. Pain can disappear without total healing of the ulcer crater and can be absent when an ulcer is present. Changes in the incidence of ulcer disease have been noted in recent years. Genetic predisposition, infection with H. pylori, and the use of anti-inflammatory drugs are involved in causation. Stress; the use of alcohol, tobacco and caffeine; and other diseases have been implicated as etiologic factors. Ulcer pain has a recognizable pattern, but the symptoms can be variable, particularly in older people and in patients taking ulcerogenic medications. The familiar complications of hemorrhage, perforation, and obstruction still occur, and nonulcer dyspepsia has not been fully explained. Duodenal ulcers have a disturbing tendency to return; new therapeutic approaches offer hope.
Comparative study of glass and antimony electrodes for continuous oesophageal pH monitoring. Oesophageal pH monitoring data are influenced by numerous patient or technique related factors, or both. In this study, data recorded with glass microelectrodes or antimony electrodes, both with external cutaneous Ag/AgCl reference electrodes, connected to two different recording devices are compared. Pearson correlation coefficients regarding the reflux index (% of the investigation time with a pH less than 4) ranged from poor to excellent (0.55 to 1.00). Differences in data recorded with glass electrodes are not significantly dependent on the recording device (r:0.93 to 1.00 for the reflux index). The correlation between data simultaneously recorded with antimony electrodes is lower, although not significantly different for the reflux index (0.90). Correlation between data recorded with glass and antimony probes is rather poor (0.55 to 0.70). Therefore data recorded with antimony electrodes cannot be compared with those recorded with glass electrodes. The mean pH recorded with glass electrodes is lower than that with antimony probes.
Cytopathologic diagnosis of benign lesions simulating choroidal melanomas. In three cases of benign pigmented lesions (one melanocytoma and two pigment epithelial adenomas) there was evidence of tumor growth and the lesions were referred to us as uveal melanomas. The fine needle aspiration biopsy specimens were correctly interpreted in the operating room as being benign tumors. The pigment granules in these benign pigmented lesions are much larger than are observed in uveal melanomas. When they were visible through the heavy pigmentation, the cellular detail appeared benign. In two cases the tumors were successfully resected with cyclochroidectomy techniques and the visual outcome was good. The third eye was studied after it had been removed at another institution. Fine needle aspiration biopsy can often differentiate a benign-simulating pigmented lesion from uveal melanoma.
Insights into the mechanisms of defective antigen presentation after hemorrhage. Although hemorrhage depresses macrophage antigen presentation (AP), a critical component in eliciting an antigen-specific immune response, it is not known which particular step in macrophage AP (i.e., uptake, ingestion, catabolism, or presentation of degraded antigens to T cells) is defective. To study this, C3H/HeN mice were bled to an arterial mean blood pressure of 35 mm Hg, maintained for 60 minutes, and then adequately resuscitated. Peritoneal and splenic macrophage cultures were prepared 2 and 24 hours after hemorrhage. Macrophage AP capacity was measured by coculturing macrophages with the T-helper cell clone D10.G4.1. To gain information about macrophage ability to digest the specific antigen conalbumin, lysosomal activity was bypassed by use of chemically denatured conalbumin peptides. To study macrophage ability to present conalbumin peptides, macrophages were fixed and D10.G4.1 proliferation in response to fragmented conalbumin was determined. AP of native conalbumin by peritoneal macrophages and splenic macrophages was depressed (p less than 0.05) by 50% (peritoneal macrophages) and 55% (splenic macrophages) 2 hours and 57% (peritoneal macrophages) and 35% (splenic macrophages) 24 hours after hemorrhage. In contrast, presentation of conalbumin peptides was only slightly decreased. In addition, the ability of fixed peritoneal macrophages and splenic macrophages to present conalbumin peptides was similar in hemorrhaged and sham mice. Because bypassing of macrophage lysosomal activity with degraded native antigens prevented the suppression of AP, the results suggest that hemorrhage-induced suppression of AP is not caused by a reduced macrophage capacity to present antigenic peptides but by decreased antigen catabolism by macrophages.
An improved palpebral spring for the management of paralytic lagophthalmos. Facial nerve paralysis with orbicularis muscle palsy can result in serious corneal complications, such as exposure, ulceration, and perforation. Eyelid springs have been used for patients with orbicularis muscle palsy to provide corneal protection while maintaining vision by restoring some kinetic eyelid function. The authors report on 24 patients with facial nerve paralysis who underwent implantation of an eyelid spring over a period of 8 years. The most common cause of orbicularis muscle paralysis was acoustic neuroma, followed by squamous cell carcinoma. Eighty-three percent of the cases successfully regained and maintained their eyelid function during the follow-up period, averaging 3.0 years. We have modified the spring to allow permanent attachment to the orbital rim by wiring. This modification of the surgical technique has minimized the most common postoperative complication: loosening of the spring from its periosteal attachment with subsequent loss of function and extrusion. In addition, transcutaneous adjustments of the spring now can be made without an incision using clasp-adjusting dental pliers. In selected patients, the placement of an eyelid spring prevents the corneal complications associated with paralytic lagophthalmos while maintaining visual function.
Adenosine use during pregnancy. Adenosine is a naturally occurring endogenous nucleoside that suppresses atrioventricular nodal conduction time, terminates supraventricular tachycardia, and restores sinus rhythm. Its use has been reported in children and adults but not in pregnant patients. This case documents the successful termination of a supraventricular tachycardia in a 39-week pregnant hypotensive patient. Emergency physicians may wish to consider adenosine use in pregnant patients needing emergency therapy or when conventional therapy fails.
Cloning of the gene for a human dopamine D4 receptor with high affinity for the antipsychotic clozapine. Dopamine receptors belong to the family of G protein-coupled receptors. On the basis of the homology between these receptors, three different dopamine receptors (D1, D2, D3) have been cloned. Dopamine receptors are primary targets for drugs used in the treatment of psychomotor disorders such as Parkinson's disease and schizophrenia. In the management of socially withdrawn and treatment-resistant schizophrenics, clozapine is one of the most favoured antipsychotics because it does not cause tardive dyskinesia. Clozapine, however, has dissociation constants for binding to D2 and D3 that are 4 to 30 times the therapeutic free concentration of clozapine in plasma water. This observation suggests the existence of other types of dopamine receptors which are more sensitive to clozapine. Here we report the cloning of a gene that encodes such a receptor (D4). The D4 receptor gene has high homology to the human dopamine D2 and D3 receptor genes. The pharmacological characteristics of this receptor resembles that of the D2 and D3 receptors, but its affinity for clozapine is one order of magnitude higher. Recognition and characterization of this clozapine neuroleptic site may prove useful in the design of new types of drugs.
Unproven methods of cancer management. Laetrile. "Laetrile" is used interchangeably with "amygdalin" to designate natural substances, derived primarily from apricots and almonds, that can release cyanide, which is lethal to living organisms. In the 1920s, Dr. Ernst T. Krebs, Sr., formulated a theory that amygdalin could kill cancer cells. His theory was inconsistent with biochemical facts and has since been modified at least twice by his son, Ernst T. Krebs, Jr. Extensive work has been done by cancer scientists to test the claim that Laetrile fights cancer. Many animal experiments in the 1970s showed a complete lack of tumor killing by Laetrile. Reviews of the medical records of patients whose cancers were claimed to be reduced or cured after Laetrile treatment found insufficient medical evidence to judge Laetrile's efficacy. Finally, in a clinical trial in cancer patients reported in 1982, Laetrile neither caused shrinkage of tumors, nor increased survival time, nor alleviated cancer symptoms, nor enhanced well-being. Several reports in the medical literature document instances in which Laetrile has caused serious, life-threatening toxicity when taken in large doses in the manner prescribed by Laetrile advocates. In light of the lack of efficacy of Laetrile and its demonstrated ability to cause harm, Laetrile should not be used to treat cancer.
Diastolic perfusion time at ischemic threshold in patients with stress-induced ischemia BACKGROUND. To evaluate the relevance of diastolic perfusion time on the mechanisms underlying stress-induced ischemia, 16 patients with coronary artery disease and seven patients with syndrome X underwent five randomized stress tests (upright and supine exercise with and without therapy, transesophageal atrial pacing). METHODS AND RESULTS. Exercise duration Time to 0.1 mV ST segment depression, heart rate, rate-pressure product, and diastolic perfusion time were evaluated for each patient during stress tests. In both groups, variability coefficients of the above-mentioned parameters were not different at rest. At ischemic threshold (0.1 mV ST segment depression) in patients with coronary artery disease, the variability coefficient of exercise duration (40.1 +/- 22.2) was significantly higher (p less than 0.0001) than those of heart rate (12.8 +/- 2.9), rate-pressure product (14.8 +/- 3.3), and diastolic perfusion time (0.39 +/- 0.1). The variability coefficient of diastolic perfusion time was also significantly (p less than 0.0001) lower than those of heart rate and rate-pressure product. Similarly, the variability coefficient of diastolic perfusion time (0.44 +/- 0.1) in syndrome X patients was significantly lower (p less than 0.0001) than those of exercise duration (28.2 +/- 9.4), heart rate (12 +/- 1.4), and rate-pressure product (14.6 +/- 1.3). CONCLUSIONS. Fixed diastolic perfusion time at ischemic threshold, despite different kinds of stress tests and variability of heart rate and rate-pressure product, indicates the relevant role of diastolic perfusion time in determining myocardial ischemia.
Testicular abscess caused by Salmonella typhi. This case, which we believe is the first report of a bacteriologically proven infection of the testis by Salmonella typhi, illustrates the occurrence of this complication in the convalescent phase of typhoid fever and the absence of a clinically evident preceding bacteremic phase. The case also emphasizes the need for prolonged antibiotic therapy and the role of surgery in treatment of relapses.