shukoor65/lab-rag-model huggingface dataset:
Invasive aspergillosis of the maxilla in an immunocompromised patient. Patients who are immunocompromised have a high susceptibility to infection, which can be fatal. Studies have shown that patients receiving chemotherapeutic and adjunctive medications have inhibited inflammatory response to microbes, particularly those increasing the potential for the development of invasive infection. Aspergillus is a fungus often found in the atmosphere. Colonization of Aspergillus in the upper respiratory tract is common. In the immunocompromised patient, Aspergillus flavus is found to be the most frequent fungus cultured in the maxillary sinus. Because of the depressed immunologic state of the patient, A. flavus can differentiate into hyphal forms producing toxins that destroy epithelial tissues. Penetration of Aspergillus into connective and vascular tissue produces thrombosis and ultimately necrosis of hard and soft tissue.
Total parenteral nutrition and tumor metastasis. A major clinical concern with providing total parenteral nutrition to the tumor-bearing host is the potential to stimulate tumor growth. This study was performed to determine the effect of total parenteral nutrition on primary tumor growth and spontaneous pulmonary metastasis in Lobund rats with subcutaneous prostate adenocarcinoma (PA-III) implants. Significant acceleration of primary tumor growth and tumor metastasis occurred in animals receiving parenteral nutrition consisting of amino acids, dextrose, and lipid or standard enteral nutrition compared to control animals. This study represents the first report of stimulating tumor metastasis with specific parenteral nutrients and clearly indicates that both primary tumor growth and tumor metastasis can be altered by exogenous substrate administration.
Peptic ulcer pathophysiology. Despite extensive research, the etiology of peptic ulcer disease remains unclear. Given the multiple processes that control acid and pepsin secretion and defense and repair of the gastroduodenal mucosa, it is likely that the cause of ulceration differs between individuals. Acid and pepsin appear to be necessary but not sufficient ingredients in the ulcerative process. It is clear that the majority of gastric ulcers and a substantial number of duodenal ulcers do not have increased gastric acid secretion. Recent research has focused more on protection and repair of the stomach and duodenum. NSAIDs cause a significant number of gastric and duodenal ulcers; this is probably due to inhibition of prostaglandin production with loss of its protective effects. In the absence of NSAIDs and gastrinoma, it appears that most gastric ulcers and all duodenal ulcers occur in the setting of H. pylori infection. Evidence is mounting in support of H. pylori as a necessary ingredient in the ulcerative process, similar to acid and pepsin. It is not known whether the bacteria or the accompanying inflammation is the more important factor in the pathophysiology. Although the pathophysiology of gastric ulcer and duodenal ulcer is similar, there are clearly differences between the two groups. Duodenal ulcer is typified by H. pylori infection and duodenitis and in many cases impaired duodenal bicarbonate secretion in the face of moderate increases in acid and peptic activity. These facts suggest the following process: increased peptic activity coupled with decreased duodenal buffering capacity may lead to increased mucosal injury and result in gastric metaplasia. In the presence of antral H. pylori, the gastric metaplasia can become colonized and inflamed. The inflammation or the infection itself then disrupts the process of mucosal defense or regeneration resulting in ulceration. A cycle of further injury and increased inflammation with loss of the framework for regeneration may then cause a chronic ulcer. Gastric ulcer often occurs with decreased acid-peptic activity, suggesting that mucosal defensive impairments are more important. The combination of inflammation, protective deficiencies, and moderate amounts of acid and pepsin may be enough to induce ulceration. Many questions remain in understanding the pathophysiology of peptic ulcer disease. The physiology and pathophysiology of mucosal regeneration and the mechanisms by which H. pylori and inflammation disrupt normal gastroduodenal function will be fruitful areas of future investigation.
Prostaglandin-stimulated recovery of the human duodenal epithelium: effects of misoprostol on ethanol damage. This study was designed to determine whether prostaglandins can stimulate the repair of human duodenal epithelium. Ten healthy volunteers were given 50 ml 40% ethanol through an endoscope onto the duodenal mucosa 1-7 cm from the pyloric sphincter; 3 min later, misoprostol (200 micrograms) or inert vehicle (5 ml) was given locally in the same way. One and 5 h later, endoscopy was repeated to evaluate the damage. The conditions of the mucosa were evaluated by endoscopy and by scanning and transmission electron microscopy in biopsies taken at time 0 and 3 min, 1 and 5 h after ethanol. The study was double-blind with a cross-over balanced design. Three minutes after ethanol administration, the duodenal mucosa showed hyperemia with hemorrhagic lesions. Under the electron microscope, the lesions were caused by vascular engorgement or red blood cell extravasation into the submucosa; the epithelium underlining lesions showed loss of superficial cells and damage to the upper layer of the mucosa. One hour after ethanol, there was a striking difference between the two treatment groups, with a substantial recovery of the duodenal epithelium in the misoprostol-treated volunteers. Although spontaneous recovery was evident in the control group, there was also a significant difference at 5 h. Our results suggest that prostaglandins are able to stimulate the recovery of the duodenal epithelium after acute damage.
Relation between p53 overexpression and established prognostic factors in breast cancer. The nuclear phosphoprotein p53 is expressed in all normal cells and appears to function in cell cycle regulation. Abnormally high levels of the protein are found in many different types of cancer. In breast carcinoma overexpression of p53 is associated with point mutations within highly conserved regions of the p53 gene. These altered genes encode stable p53 proteins that can be detected by standard immunohistochemical techniques unable to detect rapidly degraded wild-type protein. The level of p53 expression in 184 primary breast cancer specimens was assessed by immunohistochemical analysis and related to the following established prognostic factors for breast cancer: age, stage, metastatic involvement, concentration of estrogen and progesterone receptors, proliferative index, and HER-2/neu overexpression. Fifty (27%) of these primary breast cancer specimens had widespread overexpression of p53. Highly significant associations were found between p53 overexpression and late stage, metastatic spread, and low concentration of progesterone receptors. The presence of elevated levels of mutant p53 may itself be a prognostic factor in human breast cancer and activation of this oncogene may be important in the ability of a tumor to metastasize.
Proteus syndrome. Ultrastructural study of linear verrucous and depigmented nevi. Proteus syndrome is a rare hamartomatous disorder characterized by multifocal overgrowths that can involve any structure of the body. Clinical manifestations include macrodactyly, hemihypertrophy, subcutaneous masses, exostosis, cerebroid thickening of palms and soles, and linear skin lesions. About 50 cases have been described, but the ultrastructural features of the linear skin lesions have not been characterized. We describe the clinical, histologic, and ultrastructural findings for a 30-year-old patient who had a mild form of Proteus syndrome with linear lesions characterized by a mixed pattern of hyperkeratosis and depigmentation. Light microscopy of the linear nevus showed acanthosis and hyperorthokeratosis. Electron microscopy revealed extensive vacuolation at the interface between melanocytes and keratinocytes, with large aggregations of densely packed granules in the intercellular space. Melanocytes showed only slight degenerative changes. An immunohistochemical study of the expression of epidermal growth factor receptors revealed no significant abnormalities.
Descriptive epidemiologic study of epilepsy syndromes in a district of northwest Tuscany, Italy. To evaluate the prevalence of epilepsy syndromes in a district in Northwest Tuscany (Vecchiano, 9,952 inhabitants) we identified all suspected cases (probable epilepsy) from several information sources: files of local doctors, prescriptions of antiepileptic drugs (AEDs), hospital files from the center for epilepsy at the University of Pisa, medical files from university and hospital departments in Pisa, and files of the school doctors and social workers in the district of Vecchiano. All persons suspected of having epilepsy were examined; 51 cases of epilepsy were found, i.e., a prevalence rate of 5.1 in 1,000. During a previous study performed in the same district with the "house-to-house" method, a lower rate was found. Our study confirms that use of different epidemiologic investigational methods can produce different results.
Future directions of laser phototherapy for diagnosis and treatment of malignancies: fantasy, fallacy, or reality? A new and highly promising adjunctive modality for the diagnosis and therapy of malignancies is under development using lasers and tumor targeting dyes. To reach the eventual goal of clinical treatment, several current "fantasies and fallacies" regarding laser applications in medicine must be identified and their problems clearly outlined. A multidisciplinary scientific approach is also required to enable the clinical practicality of this laser targeting approach. Many new dyes and laser wavelengths are being tested to improve specific tumor uptake and/or retention, lower systemic toxicity, increase tissue penetration, and identify fluorochromes with synergistic properties to further enhance laser tumoricidal effects. Rapid technological advancements in magnetic resonance imaging may now provide an extremely sensitive way to detect and monitor laser-tissue effects, and allow efficient interstitial laser phototherapy of deep and sometimes inaccessible tumors. The current and future prospectives of the emerging field of laser phototherapy are described.
Cardiomyopathy of the aging human heart. Myocyte loss and reactive cellular hypertrophy. To determine the effects of aging on the human myocardium, 67 hearts were obtained from individuals who died from causes other than cardiovascular disease. The age interval examined was 17-90 years. Regression analysis demonstrated that the aging process was characterized by a loss of 38 million and 14 million myocyte nuclei/yr in the left and right ventricular myocardium, respectively. This loss in muscle mass was accompanied by a progressive increase in myocyte cell volume per nucleus in both ventricles. Left ventricular myocytes enlarged by 110 microns3/yr, whereas right ventricular myocytes increased by 118 microns3/yr, resulting in a preservation of ventricular wall thickness. However, the cellular hypertrophic response was unable to maintain normal cardiac mass. Left and right ventricular weights decreased by 0.70 and 0.21 g/yr, respectively. In conclusion, loss of cells and enlargement of the remaining myocytes may represent the structural basis for the reduced compensatory capacity of the aged heart and together may contribute to the development of myocardial dysfunction and failure in the elderly.
Age-related changes in the clinical and electrophysiologic characteristics of patients with Wolff-Parkinson-White syndrome: comparative study between young and elderly patients. The natural history of patients with Wolff-Parkinson-White (WPW) syndrome remains an intriguing question with respect to clinical decision-making, since serial electrophysiologic data spread over several decades in the same patient are not available in the literature. To study the age-related changes in WPW syndrome, we compared two separate groups of patients referred to this Medical Center for electrophysiologic studies because of a clinical presentation with significant arrhythmias. An elderly group of 42 patients aged 50 years or more were compared with a younger group of 51 patients aged 15 to 30 years. The groups were comparable in terms of clinical presentation, including the number of patients who had reported syncopal episodes and those requiring cardioversion of their tachyarrhythmias. Baseline electrophysiologic variables such as sinus rate; sinoatrial conduction time; corrected sinus node recovery time; AH interval; and effective refractory periods of the right atrium, atrioventricular (AV) node, and right ventricular muscle, were significantly greater in the elderly group. Similarly, the anterograde effective refractory period of the bypass tract, the shortest atrial pacing cycle length with 1:1 anterograde conduction via the bypass tract, retrograde effective refractory period of the bypass tract, the shortest ventricular pacing cycle length with 1:1 retrograde conduction via the bypass tract, the shortest consecutive preexcited R-R interval during atrial fibrillation, and the cycle length of orthodromic atrial ventricular reciprocating tachycardia were significantly greater in the elderly group.
Focal nodular hyperplasia of the liver: MR findings in 35 proved cases. MR images of 28 patients with 35 lesions of hepatic focal nodular hyperplasia were reviewed to determine the frequency of findings considered typical of this condition (isointensity on T1- and T2-weighted pulse sequences, a central hyperintense scar on T2-weighted images, and homogeneous signal intensity). Fifteen lesions were imaged at 0.6 T with T1- and T2-weighted spin-echo (SE) pulse sequences; 20 lesions were imaged at 1.5 T with T1-weighted SE and gradient-echo pulse sequences and T2-weighted SE pulse sequences. Diagnosis of focal nodular hyperplasia was made pathologically in 25 patients, with nuclear scintigraphy in four, and with follow-up imaging in six. Only seven lesions (20%) were isointense relative to normal liver on both T1- and T2-weighted images. On T1-weighted SE images, 21 lesions (60%) were isointense relative to normal liver, 12 (34%) were hypointense, and two (6%) were hyperintense. On T2-weighted SE images, 12 lesions (34%) were isointense and 23 (66%) were hyperintense relative to normal liver. A central scar was present in 17 lesions (49%) and was hypointense relative to the lesion on T1-weighted images and hyperintense on T2-weighted images. Twenty lesions (57%) were of homogeneous signal intensity throughout the lesion, except for the presence of a central scar. All three MR imaging characteristics were present in three cases (9%). We conclude that hepatic focal nodular hyperplasia has a wide range of signal intensity on MR imaging.
Mixed venous oxygen saturation for differentiating stable from unstable tachycardias. Current antitachycardia systems are incapable of adequately distinguishing stable from unstable tachycardias. Previously, integration of a pressure sensor or an impedance sensor, together with electrogram analysis, has been investigated as an improved method of identifying unstable arrhythmias. A mixed venous oxygen saturation sensor was investigated for differentiating stable from unstable paced and induced tachycardias in 10 patients. During rapid pacing at 600, 500, 400, 350, 300, and 250 msec cycle lengths, mixed venous oxygen saturation decreased as cycle length decreased. For any given cycle length, rapid ventricular pacing tended to result in greater mixed venous oxygen desaturation compared with atrial pacing. Mixed venous oxygen saturation decreased similarly during induced ventricular tachycardias at cycle lengths greater than 230 msec. However, ventricular tachycardias at cycle lengths less than or equal to 230 msec and ventricular fibrillation had no effect on mixed venous oxygen saturation until after termination. Subsequently, a mixed venous oxygen saturation-tiered therapy algorithm (cycle length less than or equal to 230 msec = unstable; cycle length greater than 230 msec and MVO2 greater than or equal to 6% over 30 seconds = unstable) was developed and was tested retrospectively in 113 paced and induced tachyarrhythmias in these 10 patients for detecting unstable tachycardias (defined as a decrease from baseline systolic arterial pressure of greater than or equal to 50 mm Hg at 15 seconds). The mixed venous oxygen algorithm had 93% sensitivity and 96% specificity compared with rate-only (rate greater than or equal to 170 beats/min) detection with 93% sensitivity and 71% specificity.
Recombinant human granulocyte-macrophage colony-stimulating factor after chemotherapy in patients with acute myeloid leukemia at higher age or after relapse. To reduce critical neutropenia after chemotherapy (CT) for acute myeloid leukemia (AML) we administered recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) to patients over the age of 65 years with newly diagnosed AML and to patients with early or second relapse. CT was 9-day 6-thioguanine, ara-C, and daunorubicin (TAD9) in newly diagnosed AML and sequential high-dose ara-C and mitoxantrone (S-HAM) for relapse. In patients whose bone marrow was free from blasts a continuous intravenous infusion of GM-CSF 250 micrograms/m2/d started on day 4 after CT. Thirty-six patients entered the study and 30 of them did receive GM-CSF. For comparison, a historical control group of 56 patients was used. Complete remission rate was 50% (18 of 36) versus 32% in controls (P = .09), and early death rate was 14% versus 39% (P = .009). Treatment with GM-CSF was not associated with major adverse events. Two patients showed a marked leukemic regrowth that was completely reversible in one patient and appeared to be GM-CSF independent in the other patient. Remission duration does not seem to be reduced after GM-CSF. Under GM-CSF the blood neutrophils recovered 6 and 9 days earlier in the TAD9 (P = .009) and S-HAM (P = .043) groups associated with a rapid clearance of infections in most patients. We conclude that GM-CSF was of therapeutic benefit to our patients and this provides a basis for larger controlled trials.
HTLV-I-associated myelopathy in a patient with adult T-cell leukemia. Disseminated erythematous papules and plaques developed in a 60-year-old man 3 years before the appearance of neurologic manifestations. A biopsy specimen of the plaque revealed Pautrier's microabscess and a dense mononuclear cell infiltration with atypical convoluted nuclei in the papillary dermis. These cells were helper/inducer T lymphocytes that expressed the interleukin 2 receptor. The patient's white blood cell count was normal, but 1% atypical lymphocytes and a high titer of anti-human T-lymphotropic virus (HTLV)-I antibody were detected in his serum. A smoldering type of adult T-cell leukemia was diagnosed. While he was being treated with PUVA, a gait disturbance developed. A high titer of anti-HTLV-I antibody, characteristic of HTLV-I-associated myelopathy, was demonstrated in his cerebrospinal fluid.
Venous thrombosis after long-term transvenous pacing in the Chinese. To determine the incidence of venous thrombosis after long-term transvenous pacing in the Chinese, venograms were performed in 50 consecutive Chinese patients seen at the pacemaker clinic. There were 25 women and 25 men. The mean age was sixty-six years (range thirty-two to eighty-one). The indications for pacing were complete heart block in 16 patients and sick sinus syndrome in the remainder. All pacemakers were of the single-chamber ventricular pacing type and had been implanted for a mean period of four years (range two to seven). In 27 patients the route of entry for the pacing electrode was through the cephalic vein and in the other 23 patients the subclavian veins were used. Of the 50 venograms, 1 showed partial and 1 showed total obstruction at the subclavian vein. Both patients (4%) were asymptomatic. All others (96%) were normal. The incidence of venous thrombosis was not related to the routes of entry of the pacing electrodes. All patients tolerated the procedure well and had no complications. It is concluded that the incidence of venous thrombosis after long-term transvenous pacing is extremely low in the Chinese (4%), and venograms are both safe and useful for identifying venous thrombosis related to transvenous pacing.
The 10-y incidence of obesity and major weight gain in black and white US women aged 30-55 y. Although the prevalence of obesity in US women is well-described, data are limited on the incidence of major weight gain and obesity. We used data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study to estimate the 10-y incidence of major weight gain (greater than or equal to 10 kg) and obesity [body mass index (BMI, in kg/m2) greater than or equal to 29] in a cohort of US women aged 30-55 y (n = 535 blacks and 2976 whites). In women not obese at baseline, blacks were 60% more likely to become obese than whites [incidence in blacks = 15.5%, 95% confidence interval (CI) = 11.2-19.7; incidence in whites = 9.7%, 95% CI = 8.6-10.8]. This higher incidence of obesity in blacks was largely due to their higher average BMI at baseline. The incidence of major weight gain was 50% higher in blacks than in whites (in blacks, 17.3%; 95% CI = 13.6-21.0; in whites, 11.7%; 95% CI = 10.3-13.1). We estimate that in black and white women, respectively, 16% and 12% of coronary heart disease is attributed to major weight gain whereas 35% and 21% is attributed to being obese.
Development of the pulmonary vasculature in newborn lambs: structure-function relationships. Our objectives were 1) to describe the quantitative light microscopy and ultrastructure of newborn lamb lungs and 2) to correlate hemodynamic changes during normoxia and hypoxia with the morphology. By light microscopy, we measured the percent muscle thickness (%MT) and peripheral muscularization of pulmonary arteries and veins from 25 lambs aged less than 24 h, 2-4 days, 2 wk, and 1 mo. At the same ages, lungs were isolated and perfused in situ and, after cyclooxygenase blockade with indomethacin, total, arterial (delta Pa), middle (delta Pm), and venous pressure gradients at inspired O2 fractions of 0.28 (mild hyperoxia) and 0.04 (hypoxia) were determined with inflow-outflow occlusion. During mild hyperoxia, delta Pa and delta Pm fell significantly between 2-4 days and 2 wk, whereas during hypoxia, only delta Pm fell. The %MT of all arteries (less than 50 to greater than 1,000 microns diam) decreased, and peripheral muscularization of less than 100-microns-diam arteries fell between less than 4 days and greater than 2 wk. Our data suggest that 1) the %MT of arteries determines normoxic pulmonary vascular resistance, because only arterial and middle segment resistance fell, 2) peripheral muscularization is a major determinant of hypoxic pulmonary vasoconstriction, because we observed a fall with age in peripheral muscularization of less than 100-micron-diam arteries and in delta Pm with hypoxia, and 3) the arterial limit of the middle segment defined by inflow-outflow occlusion lies in 100- to 1,000-microns-diam arteries.