shukoor65/lab-rag-model huggingface dataset:
Total knee arthroplasty at a Veterans Administration Medical Center. Total knee arthroplasty (TKA) was evaluated in 256 consecutive knees in a Veterans Administration hospital. Patient satisfaction and the effect of intercurrent illness were studied in addition to standard clinical and roentgenographic parameters. Evaluation of results show the superiority of condylar knee designs. In general, TKA was successful with a high degree of patient satisfaction.
Molecular mechanisms of tubulointerstitial hypertrophy and hyperplasia. Adult kidneys, which are principally composed of tubulointerstitium, do not normally regenerate or expand their working pool of functional cells at a very high rate. Loss of kidney tissue, however, can lead to some compensatory renal enlargement. The catalytic forces initiating such exchanges have not been fully articulated by current experimental endeavors. Increasing evidence, nevertheless, does suggest that factors other than simple changes in renal hemodynamics may be involved in this process. Different cellular elements in the tubulointerstitial microenvironment probably modulate changes in tubular enlargement or size through a complex cytokine network. Autocrine and paracrine stimulation of enlargement by different local growth factors also seem to play a pivotal role. After binding to cellular receptors, these factors activate signal transduction pathways resulting in expression of immediate early genes, which by themselves can synchronize the expression of subsequent genes through the medium of transacting factors. The renal enlargement response can also be modified by endocrine hormones that can activate such genes directly and/or stimulate other adjunctive processes, like receptor expression for the regional binding of growth factors. Furthermore, renal enlargement is under negative feedback of inhibitory factors like TGF beta. It is possible, for example, that special genes exist which are only expressed to arrest enlargement. It has been further suggested that activation of the Na+/H+ antiporter is a common denominator in renal enlargement. Recent findings, however, indicate that the activation of this antiporter is not always necessary, and might rather be a parallel event rather than a key phenomena in tubular enlargement. G0/G1 transition of tubular cells seems to involve similar factors in tubular hypertrophy and hyperplasia. The factors which are responsible for the final determination of the enlargement pattern (hypertrophy vs. proliferation) are unknown. The separation between hypertrophy and hyperplasia, although suggested by striking differences in cellular regulation, may be somewhat artificial, since responses leading to tubular enlargement also exist in circumstances where hyperplasia and hypertrophy are combined events. Recently it has been proposed that growth factors stimulate gluconeogenesis in proximal tubular cells producing hyperplasia, whereas factors inhibiting gluconeogenesis might induce hypertrophy. Whether the common pathway message of this intriguing hypothesis is correct still requires further validation.(ABSTRACT TRUNCATED AT 400 WORDS).
Arteriographic findings in EDTA chelation therapy on peripheral arteriosclerosis. In a randomized, double-blind, controlled study, 153 patients with claudication were each given either 20 infusions of Na2EDTA or 20 infusions of saline. Walking distances and ankle/brachial indices were measured before, during, and after treatment. In 30 patients, angiograms and transcutaneous oxygen tensions were obtained before, during, and after treatment. The patients' subjective evaluations of the effect of treatment were also recorded. It is concluded that EDTA chelation therapy has no effect in patients with intermittent claudication in the legs caused by arteriosclerosis.
Mechanisms of hypertension in diabetes. Hypertension in insulin resistance states is generally attributed to hyperinsulinemia, with resulting increases in renal sodium retention and/or sympathetic nervous system activity. However, recent data from our laboratory suggest that cellular insulin resistance, rather than hyperinsulinemia per se, may lead to hypertension. The basic tenet proposed in this review is that the common mechanism involved in the development of hypertension in both type I and type II diabetes mellitus is a deficiency of insulin at the cellular level. Recent observations suggest that impaired cellular response to insulin predisposes to increased vascular smooth muscle (VSM) tone (the hallmark of hypertension in the diabetic state). For example, recently reported studies from our laboratory demonstrate that insulin in physiological doses attenuates the vascular contractile response to phenylephrine, serotonin, and potassium chloride. Thus, insulin appears to normally modulate (attenuate) VSM contractile responses to vasoactive factors, and insulin resistance should accordingly be associated with enhanced vascular reactivity. Abnormal VSM cell calcium [Ca2+]i homeostasis may be the nexus between insulin resistance and increased VSM tone. The genetically obese, hyperinsulinemic, insulin-resistant Zucker rat demonstrates increased vascular reactivity, reduced membrane Ca2(+)-ATPase activity, increased cellular Ca2+ levels, and a marked impairment in vascular smooth muscle Ca2+ efflux compared to lean controls. Insulin stimulates membrane Ca-ATPase, blocks Ca2+ currents, and Ca2(+)-driven action potentials. Thus, an insulin-resistant state as exists in the Zucker rat may be associated with increased Ca2+ influx through voltage-dependent sarcolemmal Ca2+ channels and/or decreased production or activation of the VSM cell Ca-ATPase pump.
Adenosine thallium 201 myocardial perfusion scintigraphy. Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent coronary vasodilator and when combined with thallium 201 scintigraphy produces images of high quality, with the added advantages of a very short half-life (less than 10 seconds) and the ability to adjust the dose during the infusion, which may enhance safety and curtail the duration of side effects. The reported sensitivity and specificity of adenosine thallium 201 scintigraphy for the detection of coronary artery disease are high and at least comparable with imaging after exercise or dipyridamole administration.
Follicular accentuation of leukocytoclastic vasculitis in an HIV-seropositive man. Report of a case and review of the literature. Palpable purpura in a follicular localization developed in association with acute epididymitis in a white man who was seropositive for the human immunodeficiency virus (HIV). Biopsy specimens revealed a leukocytoclastic vasculitis with follicular accentuation. With antibiotic therapy the vasculitis resolved, but it recurred during repeated episodes of the epididymitis. Follicular accentuation of skin disease is often seen in HIV-seropositive patients. Leukocytoclastic vasculitis with a follicular localization may be the presenting skin manifestation of HIV infection.
Clinical survey of ischemic cerebrovascular disease in children in a district of Japan. Ischemic cerebrovascular disease in children is relatively rare. To clarify the clinical features of ischemic stroke occurring in infants and children, we evaluated 54 cases of cerebral infarction, excluding cases of moyamoya disease, in patients less than 16 years old at 24 clinics in the Tohoku (northeast) district of Japan. We observed two incidence peaks, one in little children and the other in junior high school students. Infection and minor head trauma were more frequently seen prior to ischemic strokes than was heart disease. The middle cerebral artery region, including the basal ganglia, was most commonly affected (49 patients, 91%) on computed tomograms. Angiography was performed in 48 patients (89%) and showed various types of occlusive lesions, mostly affecting the middle cerebral artery. Hemiparesis was the most common form of disability following ischemic strokes (48 patients, 89%). Surgical treatment was carried out in seven patients (13%). The clinical course of these cases showed that the recovery of children after a stroke tends to be better than that of adults, but that permanent disabilities, such as hemiparesis or mental retardation, occur commonly. Further investigation of juvenile cerebrovascular disease is important to prevent ischemic strokes in children.
Sinus parasystole. Sinus parasystole is the expression of a protected nondominant sinus pacemaker, which is totally independent of the dominant rhythm. Two forms of sinus parasystole are described: (1) an active form, where both the dominant and the parasystolic pacemakers are located within the sinus node and (2) a passive form, where the basic rhythm is ectopic and the sinus pacemaker is protected as a result of complete retrograde SA block. Three cases of sinus parasystole are analyzed. In the active form of the arrhythmia the parasystolic sinus P waves are identical to those of the basic sinus rhythm. The diagnosis is suggested by variably coupled premature sinus P waves occurring with mathematically related intervals. This relationship between the parasystolic intervals can not be precise whenever complicating factors such as modulation occur. The recognition of active sinus parasystole is difficult, since the parasystolic P waves do not differ from basic P waves, so that the pattern resembles that of sinus arrhythmia or sinus extrasystoles. The passive form of sinus parasystole is more easily recognized due to the clear-cut difference between the dominant ectopic atrial waves and the "parasystolic" sinus P waves, which manifest with variable coupling intervals and reflect mathematically related intervals in between.
Familial pulmonary hypertension in association with an abnormal hemoglobin. Insights into the pathogenesis of primary pulmonary hypertension. A kindred with a familial hemoglobinopathy and familial primary pulmonary hypertension with autosomal dominant transmission has been identified. Affected family members were obvious from their cyanosis due to a reduced affinity for oxygen by the hemoglobin variant. The mother and one child had clinical pulmonary hypertension, whereas two siblings had cyanosis and preclinical pulmonary vascular disease as evidenced by abnormal perfusion lung scans and elevated levels of fibrinopeptide A in the face of normal pulmonary hemodynamics. In one, pulmonary hypertension could be induced with exercise. The studies on this family support the hypothesis that primary pulmonary hypertension may be initiated by abnormalities of the pulmonary vascular bed that predispose to in situ thrombosis. The possible common genetic transmission of the two diseases offers the speculation that the gene that confers predisposition to pulmonary hypertension may be located near the gene responsible for beta globulin.
Structural alterations of microvascular smooth muscle cells in reduced renal mass hypertension. Loss of microvessels (anatomic rarefaction) occurs in chronic reduced renal mass (RRM) hypertension and is mediated via structural degeneration of vascular smooth muscle (VSM) and endothelial cells. The purpose of the present study was to determine if structural changes occur in VSM cells of the microvessels that remain in the tissue of rats with chronic RRM hypertension. Samples of cremaster muscles were taken from normotensive control rats and rats with acute (3-7 days) and chronic (14-28 days) RRM hypertension (75% reduction in kidney mass with 4% NaCl loading). The samples were fixed in situ and processed for light and electron microscopy. Ultrastructural morphology of VSM cells in terminal arterioles of control animals was normal. Although VSM morphology in many microvessels of RRM hypertensive rats was also normal, some vessels exhibited structural changes that were not present in arterioles of the normotensive animals. The most striking change was the appearance of more extensive dense bodies anchoring the contractile filaments around the outer membrane of the cells. Extreme vasoconstriction was observed in some arterioles of RRM rats as long as 2 weeks after salt loading. Focal areas of VSM cell proliferation were evident. Many of the changes occurring in RRM were detected as early as 1 week after the onset of hypertension. These observations suggest that renal mass reduction-salt loading hypertension is associated with early structural and functional changes in the VSM cells.
Increased platelet aggregate formation in patients with chronic airflow obstruction and hypoxaemia. Platelet aggregate formation in vivo was assessed by means of the platelet aggregate ratio and from platelet release products (beta thromboglobulin, platelet factor 4, thromboxane B2) in 23 patients with chronic airflow obstruction with and without hypoxaemia and in 10 control subjects without respiratory disease. Eight of the 11 hypoxaemic patients were having long term oxygen therapy. The platelet aggregate ratio was lower in the hypoxaemic patients (0.88 (SE 0.03] than in the non-hypoxaemic (0.97 (0.01] and control groups (1.00 (0.02], and there was a trend to lower aggregate ratios in the more hypoxaemic patients. Platelet release products in the peripheral venous blood were not increased in the patients or control subjects. Platelet behaviour is altered in chronic hypoxaemia and this enhanced platelet activity could contribute to the pulmonary vascular damage found in these patients through direct effects or mediator release.
Cholecystokinin cholescintigraphy: detection of abnormal gallbladder motor function in patients with chronic acalculous gallbladder disease. CCK cholescintigrams were performed in 374 patients with recurrent postprandial right upper quadrant pain, biliary colic, and a normal gallbladder sonogram and/or cholecystogram. The results of these examinations were correlated with the patients' final medical/surgical diagnoses. Twenty-seven patients recruited as control volunteers without objective clinical evidence of biliary disease also underwent CCK cholescintigraphy to determine if the degree of gallbladder contraction post-CCK differs in symptomatic versus asymptomatic subjects. Decreased gallbladder motor function was identified (maximal gallbladder ejection fraction response to CCK less than 35%) in 94% of patients with histopathologically confirmed chronic acalculous cholecystitis or the cystic duct syndrome and in 88% of patients clinically believed to have chronic acalculous biliary disease. Decreased gallbladder motor function does not distinguish symptomatic from asymptomatic gallbladder disease.
Prevalence of lipoprotein (a) [Lp(a)] excess in coronary artery disease. Lipoprotein (a) [Lp(a)] is composed of 1 low-density lipoprotein (LDL) particle, to which 1 molecule of apolipoprotein (a) is covalently linked. Elevated levels of Lp(a) have been associated with coronary artery disease (CAD) and Lp(a) has been shown to be highly heritable. Our purpose was to determine the prevalence of familial Lp(a) excess in patients with CAD. We determined plasma levels of Lp(a) in 180 patients (150 men and 30 women) with angiographically documented CAD before age 60 years, and in 459 control subjects (276 men and 183 women) clinically free of cardiovascular disease. In addition, Lp(a) levels were determined in families of 102 of the CAD probands (87 men and 15 women). No gender differences in Lp(a) levels were observed between men and women (patients or control subjects). Patients with CAD had higher Lp(a) levels than did control subjects (19 +/- 21 vs 13 +/- 15 mg/dl, p less than 0.001). The prevalence of Lp(a) excess (defined as greater than 90th percentile of controls) was 17% in patients with CAD (p less than 0.05). Lp(a) levels were not correlated with cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol or apolipoproteins A-I or B. There was a weak correlation between Lp(a) and triglycerides (r = 0.166, p less than 0.05) in patients and control subjects. Stepwise discriminant analysis revealed that Lp(a) was a risk factor for the presence of CAD in men, independent of smoking, hypertension, diabetes, LDL and HDL cholesterol, or apolipoprotein A-I and B levels. Family studies revealed that Lp(a) levels are strongly genetically determined.
Rubella prevention. Recommendations of the Immunization Practices Advisory Committee (ACIP). These revised Immunization Practices Advisory Committee (ACIP) recommendations for the prevention of rubella update the previous recommendations (MMWR 1984;33:301-10,315-8) to include implementation of a new two-dose schedule for measles-mumps-rubella (MMR) vaccine. Current information about vaccine effectiveness, duration of immunity, vaccination in pregnancy, and progress in controlling congenital rubella syndrome (CRS) is also included.
Complete repair of atrioventricular septal defect. We report our experience with 103 consecutive children who underwent repair of complete atrioventricular septal defect between 1971 and 1990. Ninety-one patients were less than 18 months old (mean age, 6.2 months; mean weight, 5.8 kg) and were repaired using deep hypothermia and circulatory arrest. There were 15 perioperative deaths. Twelve patients were older (mean age, 40.2 months; mean weight, 18.9 kg) and were repaired using moderate hypothermia and cardiopulmonary bypass. There were two perioperative deaths. Repairs were performed with the single-patch technique. Four younger patients required repeat repair to control residual mitral regurgitation. Two of the older children required late reoperation to replace one or both atrioventricular valves. Three younger children underwent pulmonary artery banding initially; 1 died after complete repair. Three older children underwent initial pulmonary artery banding; 2 died at definitive repair, and the survivor required pulmonary artery reconstruction, which was repeated subsequently. Since 1977 our policy has been to perform primary definitive repair whenever possible. Two patients died late from unrelated causes. At the most recent follow-up the majority of patients had no or minimal symptoms. We continue to advocate primary definitive repair whenever possible using the single-patch technique in symptomatic patients with complete atrioventricular septal defect.
Crohn's disease of the small bowel. Crohn's disease is a perplexing panintestinal disease whose etiology is unknown. Symptoms and complications vary greatly from patient to patient. Despite the fact that no cure exists, thoughtful, well-planned therapy and appropriate timely intervention, where needed, can result in maintenance of a high quality of life for affected patients.
Ballistic trauma to the abdomen: shell fragments versus bullets. Two-hundred ninety-nine patients who sustained penetrating ballistic trauma to the abdomen were divided into two groups: Group A consisted of 133 patients with shell fragment injuries from mortar artillery and Group B of 166 patients with bullet injuries from rifles and automatic or semiautomatic weapons. Both groups were analyzed retrospectively in order to compare the extent of injury and outcome. In Group A, the findings at laparotomy were negative in 15 of 133 patients (10%) compared with 9 of 166 patients (5%) in Group B (p less than 0.05). The most commonly injured abdominal organs in Group A were the colon (42%), liver (22%), small bowel (20%), stomach (14%), diaphragm (11%), spleen (10%), major vessels (9%), and kidney (9%). The abdominal organs commonly injured in Group B were the colon (50%), small bowel (41%), liver (33%), major vessels (20%), diaphragm (17%), stomach (15%), spleen (15%), and kidney (15%). Associated extra-abdominal injuries were present in 26% of Group A patients and in 21% of Group B patients (p less than 0.05). Major postoperative complications occurred in 7.5% and 8.4% of the patients in Group A and Group B, respectively (p less than 0.05). Perioperative mortality was 2.3% in Group A versus 7.2% in Group B (p less than 0.01). Our data suggest that high energy bullets to the abdomen cause higher tissue penetration and a greater blast effect than shell fragments.
Recurrent aphthous ulcers in association with HIV infection. Description of ulcer types and analysis of T-lymphocyte subsets. This study was conducted to characterize the recurrent aphthous ulcers (RAU) found in association with human immunodeficiency virus (HIV) infection, to examine evidence for increased severity of the ulcers with HIV disease, and to determine whether increased severity is associated with abnormalities of peripheral blood lymphocyte subsets. Seventy-five HIV-seropositive patients with RAU were followed for up to 2 years, and lymphocyte subsets were analyzed in 42. Minor, herpetiform, and major ulcer types were seen, but unexpectedly, 66% of the patients had the usually uncommon herpetiform and major types. These types were temporally associated with symptomatic HIV disease. Patients with major RAU were significantly more immunosuppressed than those with minor or herpetiform RAU in that they had fewer CD4 and CD8 lymphocytes (p less than 0.05). The lesion of RAU is considered to represent a local breakdown in immunoregulation. The systemic immune imbalance seen with HIV disease may amplify the local defect and lead to more severe ulcers.
Formation of neutralizing antibodies against natural interferon-beta, but not against recombinant interferon-gamma during adjuvant therapy for high-risk malignant melanoma patients. In an adjuvant clinical trial, 34 high-risk malignant melanoma patients were treated with natural interferon (IFN)-beta and recombinant IFN-gamma. Patients with tumor location on head, neck, and trunk received 3 million IU IFN-beta intravenously (IV) three times weekly for 24 weeks. Patients with tumor location on the extremities received subcutaneous (SC) injection of 2 million IU of IFN-beta distal the locoregional lymph nodes instead. All patients were given 50 micrograms IFN-gamma SC on 3 consecutive days every 4 weeks. Antibody formation was detected by coincubation of IFN and patients' serum and assessment of the inhibition of the cytopathic effect by a virus suspension. Soluble interleukin-2 receptors (sIL-2R) were determined by enzyme-linked immunosorbent assay (ELISA) technique. No antibodies against IFN-gamma were observed. The overall incidence of antibody formation to IFN-beta was 55.8% (19/34). Ninety-two percent of the SC-treated patients (13/14) and 30% (six of 20) of the IV-treated patients developed antibodies. Soluble interleukin-2 receptors were found to be significantly lower in antibody-positive patients than in antibody-negative patients. The authors conclude that IFN-beta antibody formation is frequent and might influence IFN induced sIL-2R elevation in vivo.
Repair of coarctation of the aorta in children: postoperative morphology. To determine the morphologic sequelae after surgical repair of coarctation of the aorta, the authors retrospectively reviewed angiograms and hemodynamic and clinical data on 215 patients who underwent cardiac catheterization after surgical repair of coarctation of the aorta during a 13-year period. Ninety-seven patients (45%) underwent coarctation resection with end-to-end anastomosis; 92 (43%), subclavian-flap angioplasties; and 26 (12%), synthetic-patch repairs. Sixty-four patients (30%) had an "aneurysm," defined as a measurement ratio of repair site to diaphragmatic aorta greater than 1.5. Transverse-arch or isthmic hypoplasia or recoarctation was detected in 86 patients (40%) and was most commonly associated with septal defects or obstruction of the left ventricular outflow tract. Pullback systolic pressure gradients at catheterization were significantly higher (P = .0001) in the patients with transverse-arch hypoplasia and recoarctation than in those with ratios of transverse arch to diaphragmatic aorta greater than 0.9. Significant postoperative arch obstructions can be predicted with measurement ratios on the basis of the diameter of the abdominal aorta.