123rc/medical_text huggingface dataset:
Thymoma: results of 241 operated cases Clinical and histopathological aspects of 241 thymomas were reviewed. One hundred sixty of the patients with thymoma had myasthenia gravis and 15 had other autoimmune diseases; 55% of the thymomas were encapsulated and 45% invasive. Operation was radical resection in 87.5% of the patients, subtotal resection with residual tumor in 8.7%, and simple biopsy in 3.7%. A tumor relapse was observed in 24 patients (10%): 2 (1.5%) of 133 with encapsulated thymomas and 22 (20.4%) of 108 with invasive thymomas; among these patients, a relapse was found in 20.6% of the patients who received radiotherapy postoperatively and in 24.6% who did not. Adverse prognostic factors were clinical stage IVa (multiple pleural nodes), not feasible resection (for technical reasons), inoperable tumor relapse, and association with one of the following autoimmune diseases: pure red cell aplasia, hypogammaglobulinemia, and lupus erythematosus. Conversely, myasthenia gravis is now a curable disease; it contributes to early discovery of associated thymoma, thus allowing a better survival for patients with thymoma who have myasthenia gravis compared with patients with thymoma but without myasthenia gravis (p less than 0.05). Postoperative radiotherapy does not seem necessary after removal of encapsulated thymomas, but it is advisable in case of invasive thymomas, regardless of the extent of the resection.
Clot-trapper device for transjugular thrombectomy from the inferior vena cava. The clot-trapper device for transjugular thrombectomy was used in 10 dogs with acute thrombosis and two dogs with chronic thrombosis. In eight of these animals, the clots were trapped with the clot-trapper device, then a mechanical thrombectomy device was used to destroy the clots. In 10 animals, including eight with in vitro thrombi and two with in situ thrombi, thrombi were efficiently trapped with the clot-trapper device. In two animals, pulmonary embolism occurred because of a discrepancy between the diameter of the inferior vena cava and the diameter of the bag opening. After increasing the size of the loop to match the diameter of the inferior vena cava, trapping of all thrombi was possible in both experiments (acute and chronic thrombosis). The clot-trapper device, in conjunction with an embolectomy balloon catheter and/or a mechanical thrombectomy device, facilitates the removal of thrombi from the inferior vena cava and iliac veins.
Risk factors for emphysema. Cigarette smoking is associated with a reduction in the association rate constant of lung alpha 1-antitrypsin for neutrophil elastase. The increased risk of developing emphysema among individuals who smoke cigarettes and who have normal levels of alpha 1-antitrypsin (alpha 1AT) is hypothesized to result from a decrease in the antineutrophil elastase capacity of the lower respiratory tract alpha 1AT of smokers compared with nonsmokers. To evaluate this hypothesis we compared the time-dependent kinetics of the inhibition of neutrophil elastase by lung alpha 1AT from healthy, young cigarette smokers (n = 8) and nonsmokers (n = 12). alpha 1-antitrypsin was purified from lavage fluid using affinity and molecular sieve chromatography, and the association rate constant (k assoc) for neutrophil elastase quantified. The k assoc of smoker plasma alpha 1AT (9.5 +/- 0.5 X 10(6) M-1s-1) was similar to that of nonsmoker plasma (9.3 +/- 0.7 X 10(6) M-1s-1, P greater than 0.5). In marked contrast, the k assoc of smoker lower respiratory tract alpha 1AT was significantly lower than that of nonsmoker alpha 1AT (6.5 +/- 0.4 X 10(6) M-1s-1 vs. 8.1 +/- 0.5 X 10(6) M-1s-1, P less than 0.01). Furthermore, the smoker lower respiratory tract alpha 1AT k assoc was significantly less than that of autologous plasma (P less than 0.01). When considered in the context of the concentration of alpha 1AT in the lower respiratory tract epithelial lining fluid, the inhibition time for neutrophil elastase of smoker lung alpha 1AT was twofold greater than that of nonsmoker lung alpha 1AT (smoker: 0.34 +/- 0.05 s vs. nonsmoker: 0.17 +/- 0.05 s, P less than 0.01). Consequently, for concentrations of alpha 1AT in the lower respiratory tract it takes twice as long for an equivalent amount of neutrophil elastase to be inhibited in the smoker's lung compared with the nonsmoker's lung. These observations support the concept that cigarette smoking is associated with a decrease in the lower respiratory tract neutrophil elastase inhibitory capacity, thus increasing the vulnerability of the lung to elastolytic destruction and thereby increasing the risk for the development of emphysema.
Dimerization of mammalian progesterone receptors occurs in the absence of DNA and is related to the release of the 90-kDa heat shock protein. In this study we have demonstrated that dimerization of mammalian progesterone receptors (PR) occurs in the absence of DNA. A specific immune coisolation assay was performed on extracts of T-47D human breast cancer cells with a monoclonal antibody specific for the full-length B form of progesterone receptor (PR-B). This resulted in coisolation of significant amounts of truncated form-A receptors (PR-A), indicating the presence of stable PR-A.PR-B dimers in solution. A positive correlation was observed between the ability of different receptor forms to oligomerize in solution and their ability to bind to specific DNA sequences. The ability to form stable PR-A.PR-B oligomers in the absence of DNA was also found to correlate with release of 90-kDa heat shock protein (hsp90) from the unactivated PR complex. These results support the hypothesis that dimerization in the absence of DNA is an important mechanism controlling receptor DNA-binding function and that hsp90 release may be a key step regulating dimerization. This suggests that hsp90 may function to repress DNA-binding activity indirectly by blocking receptor dimerization.
Upper gastrointestinal pathology in familial adenomatous polyposis: results from a prospective study of 102 patients. Multiple gastric and duodenal biopsy specimens from 102 asymptomatic patients with familial adenomatous polyposis, taken during a prospective endoscopic screening programme were examined. One hundred patients had microscopic gastroduodenal pathology, often in the absence of macroscopic lesions. Adenomas were found in 94 patients in the duodenum, in the second and third parts. Hyperplasia of villous and crypt epithelium was also seen, sometimes in the absence of adenomas: this may be a precursor of neoplastic change. In the stomach fundic gland polyps were the commonest abnormality, seen microscopically in 44 patients. Chronic antral gastritis was common in patients without fundic polyps. Gastric adenomas were present in six patients, all of whom also had duodenal adenomas. If duodenal adenomas in familial adenomatous polyposis have a similar malignant potential to those in the colorectum sequential endoscopy and biopsy are necessary to detect cancer in these patients.
A hypothesis: nonsteroidal anti-inflammatory drugs reduce the incidence of large-bowel cancer. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit prostaglandin synthesis and tumor growth in the rodent colon. We assessed NSAID use in relation to risk of human large-bowel cancer in a hospital-based, case-control study of 1326 patients with colorectal cancer and 4891 control patients. For regular NSAID use that continued into the year before interview, the multivariate relative risk estimate was 0.5 (95% confidence interval, 0.4 to 0.8); the estimate decreased as the duration of use increased, but the trend was not statistically significant. Similar results were obtained whether cancer or non-cancer controls were used, and the inverse association was apparent for both colon cancer and rectal cancer in men and women and in subjects younger and older than 60 years. Regular NSAID use that had been discontinued at least 1 year previously and non-regular use were not associated with risk. Almost all regular NSAID use was of aspirin-containing drugs. The present data suggest that the sustained use of NSAIDs reduces the incidence of human large-bowel cancer.
Body surface mapping of high-frequency components in the terminal portion during QRS complex for the prediction of ventricular tachycardia in patients with previous myocardial infarction. To study the clinical significance of terminal QRS high-frequency components for the prediction of ventricular tachycardia, an 87-lead body surface signal-averaged mapping was performed in 21 healthy subjects (control) and in 41 patients with previous myocardial infarction (anterior, 20; inferior, 21). Mapping data were analyzed and averaged (129.7 +/- 26.5 beats) for 160 seconds, and the signal-averaged beat was filtered with a bidirectional bandwidth (80-250 Hz) digital filter. J-point was determined from the 87-lead RMS voltage of nonfiltered QRS. For each lead, we calculated the sum of the absolute value of filtered QRS from 20 msec ahead of the J-point to the J-point (A-20). The body surface distribution of A-20 was expressed as A-20 map. The maxima in A-20 maps were mainly located on the upper sternal region in healthy subjects, on the left anterior chest in patients with previous anterior myocardial infarction, and on the central anterior chest in patients with previous inferior myocardial infarction. In the patients in both the group with anterior myocardial infarction and the group with inferior myocardial infarction, the value of maximum was significantly greater than in the subjects in the control group (0.181 +/- 0.086 and 0.138 +/- 0.048, respectively, vs. 0.075 +/- 0.031 mV.msec; p less than 0.01). In patients with myocardial infarction (n = 41), the value of maximum was significantly greater with ventricular tachycardia (n = 11) than without ventricular tachycardia (n = 30) (0.240 +/- 0.076 vs. 0.130 +/- 0.043 mV.msec; p less than 0.01).
Blood loss reduced during hip arthroplasty by lumbar plexus block. We measured the blood loss during and after hip replacement in two groups of women, each consisting of 10 patients. In one group the lumbar plexus was infiltrated with bupivacaine, in the other it was not. The group in whom the plexus was blocked had significantly less blood loss.
Inflammatory pseudotumor of intra-abdominal lymph nodes manifesting as recurrent fever of unknown origin: a case report. A 27-year-old man presented with a 7-month history of debilitating recurrent fever and weight loss. Extensive clinical evaluation led to the discovery of splenomegaly and retroperitoneal lymphadenopathy. The patient underwent splenectomy as well as liver and lymph node biopsy. Histologic examination of the lymph nodes, but not the liver and spleen, revealed inflammatory pseudotumor of lymph nodes. The patient has remained asymptomatic for more than 3 years following the surgical procedure despite the absence of further intervention. Inflammatory pseudotumor of lymph nodes should be considered in the differential evaluation of prolonged or relapsing fever of unknown etiology.
Elevated serum concentrations of IgE antibodies to environmental antigens in HIV-seropositive male homosexuals. Forty-five homosexual male subjects with human immunodeficiency virus (HIV) infection, who received care during a 4-month period in an ambulatory center for acquired immunodeficiency syndrome (AIDS), were classified according to their principal presentation with characteristic secondary infections (CDC group IV C, N = 28), cancers (IV D, N = 10), or limited or no symptoms (groups II, III, IV A, or IV B, N = 7). The incidence of allergic rhinitis and conjunctivitis increased after HIV seroconversion by approximately twofold in patients of groups IV C and IV D. The mean serum concentration of IgE was significantly higher for group IV C than for the other HIV-seropositive groups and for a control group of 45 HIV-seronegative homosexual male subjects from the same community who were studied concurrently. More patients in groups IV C and IV D had positive RASTs for a panel of environmental antigens than patients in the other HIV-seropositive groups and the HIV-seronegative control group. Patients with AIDS presenting with typical secondary infections thus have a high frequency of some clinical and laboratory manifestations of allergic diseases.
Nasolacrimal obstruction after inferior meatus nasal antrostomy. Transient epiphora following rhinoplasty or intranasal procedures is a common occurrence. Permanent nasolacrimal duct obstruction, however, is rare. This article documents four cases of nasolacrimal duct obstruction following intranasal antrostomy. Three patients were cured by dacryocystorhinostomy and a fourth refused surgery. The anatomy of the nasolacrimal duct in the inferior meatus has considerable variation. Although the duct typically opens in the inferior meatus immediately under the insertion of the inferior turbinate, the orifice can be a single hole, a slit, multiple holes, or a trough, and can be located anywhere from 30 to 40 mm dorsal to the anterior nares. We review the embryology and anatomy of the nasolacrimal orifice in the nose and make recommendations for safe surgery in the inferior meatus.
Acral melanoma: a review of 185 patients with identification of prognostic variables. One hundred eight-five patients with acral melanoma treated since 1972 were reviewed. These included 53 subungual lesions, 123 plantar lesions, and 9 palmar lesions. Eighty percent presented with stage I disease. Mean age was 57 years. Males outnumbered females 1.1:1. Seventeen percent (17%) were blacks. Actuarial 10-year survival was 58% for stage I patients and 35% for stage II patients. Univariate Cox regression analyses identified 5 prognostic variables affecting survival: stage at diagnosis (P less than 0.001), race (P less than 0.001), ulceration (P = 0.012), Clark's level (P = 0.014), and thickness of the primary lesion (P = 0.013). Factors unrelated to survival included sex of the patient, site (volar vs. subungual), histology, and treatment with amputation. Multivariate analysis for patients with stage I lesions identified race (P = 0.001) and ulceration (P = 0.018) as significant variables, with thickness approaching significance (P = 0.094). In an additional series of 71 patients with melanomas arising from extremity sites near the junction of glabrous and non-glabrous skin, survival was significantly poorer for those arising from glabrous skin (P = 0.024), and reflects a higher incidence of metastatic disease at diagnosis. Specific active immunotherapy was the principal adjuvant used for these patients, and survival was comparable to that reported with regional perfusion therapy. Acral melanoma a) has a strong racial predilection, b) carries a grave prognosis, and c) arises from glabrous skin. It is a clinical entity distinct from other extremity melanomas. Surgical management with either wide excision or amputation is appropriate for the primary lesion.
Reversible nerve conduction block in patients with polyneuropathy after ultrasound thermotherapy at therapeutic dosage. This study investigated the effect of ultrasound on nerve conduction in patients with polyneuropathy. Eight able-bodied controls (Group C) and 16 patients with clinical and physiologic evidence of polyneuropathy were tested. Eight patients (Group NP) had no aching pain symptoms; eight patients (Group P) had severe aching pain, burning sensation, unpleasant tingling, and/or hyperesthesia in the lower extremities. For two minutes, therapeutic ultrasound in doses of 0.5, 1.0, and 1.5W/cm2 were applied over the anterior surface of the leg along the pathway of the deep peroneal nerve. Peroneal nerve conduction studies were performed before, during, and after ultrasound treatment. The compound muscle action potential (CMAP) was recorded from the extensor digitorum brevis muscle. Nerve conduction studies on all eight patients in Group P revealed a significant decrease (41.4% and 44% reduced for doses of 1.0W/cm2 and 1.5W/cm2, respectively; p less than .05) in amplitude of CMAP (from baseline to the first negative peak), and an increase (6.4% and 6.7% increased for doses of 1.0W/cm2 and 1.5W/cm2, respectively; p less than .05) in proximal latency one minute after ultrasound application with a dose of 1.0 or 1.5W/cm2, but not with a dose of 0.5W/cm2 (p greater than 0.1). Changes returned to pretreatment values within five minutes of cessation of ultrasound therapy. In Groups C and NP, there were no significant changes in amplitudes of CMAP or proximal latency before, during, or after ultrasound therapy at a dose of 0.5, 1.0, or 1.5W/cm2. It was concluded that ultrasonic therapy with therapeutic dosage may cause a reversible conduction block on patients with painful polyneuropathy.
Tay-Sachs disease in Moroccan Jews: deletion of a phenylalanine in the alpha-subunit of beta-hexosaminidase. Tay-Sachs disease is an inherited lysosomal storage disorder caused by defects in the beta-hexosaminidase alpha-subunit gene. The carrier frequency for Tay-Sachs disease is significantly elevated in both the Ashkenazi Jewish and Moroccan Jewish populations but not in other Jewish groups. We have found that the mutations underlying Tay-Sachs disease in Ashkenazi and Moroccan Jews are different. Analysis of a Moroccan Jewish Tay-Sachs patient had revealed an in-frame deletion (delta F) of one of the two adjacent phenylalanine codons that are present at positions 304 and 305 in the alpha-subunit sequence. The mutation impairs the subunit assembly of beta-hexosaminidase A, resulting in an absence of enzyme activity. The Moroccan patient was found also to carry, in the other alpha-subunit allele, a different, and as yet unidentified, mutation which causes a deficit of mRNA. Analysis of obligate carriers from six unrelated Moroccan Jewish families showed that three harbor the delta F mutation, raising the possibility that this defect may be a prevalent mutation in this ethnic group.
The reliability of palpation in the assessment of tumours. There is now a joint UICC-AJC classification for cervical lymph nodes based mainly on the size of the nodes. There is a recognized error in palpation, not only for detecting the presence of tumour but also its size. This study used an animal tumour model system to compare the ability of 6 independent observers of varying experience to detect and stage superficially transplanted growths. A preclinical medical student was as good as a Consultant ENT Surgeon in predicting the presence of tumour but the ability to stage tumours accurately was related to experience. Whilst the most experienced observers accurately estimated the size of tumours less than 2 cm, they were less accurate for larger (greater than 2 cm) tumours which were constantly understaged. This phenomenon may have important clinical implications particularly related to current nodal staging criteria.
Immunoglobulins from animal models of motor neuron disease and from human amyotrophic lateral sclerosis patients passively transfer physiological abnormalities to the neuromuscular junction. Amyotrophic lateral sclerosis (ALS) is a devastating human disease of upper and lower motoneurons of unknown etiology. In support of the potential role of autoimmunity in ALS, two immune-mediated animal models of motoneuron disease have been developed that resemble ALS with respect to the loss of motoneurons, the presence of IgG within motoneurons and at the neuromuscular junction, and with respect to altered physiology of the motor nerve terminal. To provide direct evidence for the primary role of humoral immunity, passive transfer with immunoglobulins from the two animal models and human ALS was carried out. Mice injected with serum or immunoglobulins from the animal disease models and human ALS but not controls demonstrated IgG in motoneurons and at the neuromuscular junction. The mice also demonstrated an increase in miniature end-plate potential (mepp) frequency, with normal amplitude and time course and normal resting membrane potential, indicating an increased resting quantal release of acetylcholine from the nerve terminal. The ability to transfer motoneuron dysfunction with serum immunoglobulins provides evidence for autoimmune mechanisms in the pathogenesis of both the animal models and human ALS.
Mechanical restraint use among residents of skilled nursing facilities. Prevalence, patterns, and predictors The patterns of and risk factors for mechanical restraint use were determined in 12 skilled nursing facilities. Restraints were being used for 59% of residents at the beginning of the study; 31% of remaining residents were restrained during the follow-up year. No facility characteristic was associated with restraint use. The resident characteristics independently associated with initiation of restraints were older age, disorientation, dependence in dressing, greater participation in social activities, and nonuse of antidepressants. Unsteadiness (72%), disruptive behavior such as agitation (41%), and wandering (20%) were the most frequently cited reasons for initiation of restraints.
The expression of progesterone receptors coincides with an arrest of DNA synthesis in human breast cancer. Two main models to account for the heterogeneous expression of estrogen receptors (ER) and progesterone receptors (PR) in human breast cancer have been proposed: the clonal model and the stem cell model. The authors previously provided evidence supporting the stem cell model since it was found that most of the proliferating cells in ER-positive (ER+) human breast cancer lack ER and that the ER-negative (ER-) and ER+ subpopulations are interrelated. The authors have analyzed in eighteen ER+/PR+ primary breast tumors the simultaneous expression of ER or PR (by immunohistochemistry) and DNA synthesis (by autoradiography) after 30 minutes of 3H-thymidine incorporation. The authors demonstrated that: (1) the average numbers of ER+ and PR+ cells were similar (36.8 +/- 10.7% and 39.3 +/- 17.6%, respectively); (2) The thymidine-labeling indexes of the ER+, ER-, PR+, and PR- subpopulations were 0.53 +/- 0.69%, 0.74 +/- 0.49%, 0.21 +/- 0.21 and 0.94 +/- 0.54%, respectively; and (3) 75.2% of the DNA-synthesizing cells were ER-, and 88.8% of them were PR-. The authors conclude that the cellular subpopulations expressing ER and PR were not identical, and the expression of PR was associated with a lower rate of cellular proliferation than was ER expression.