123rc/medical_text huggingface dataset:
Down-regulation of LFA-1 adhesion receptors by C-myc oncogene in human B lymphoblastoid cells. The function of the c-myc gene and its role in tumorigenesis are poorly understood. In order to elucidate the role of c-myc oncogene activation in B cell malignancy, the phenotypic changes caused by the expression of c-myc oncogenes in human B lymphoblastoid cells immortalized by Epstein-Barr virus were analyzed. C-myc oncogenes caused the down-regulation of lymphocyte function-associated antigen-1 (LFA-1) adhesion molecules (alpha L/beta 2 integrin) and loss of homotypic B cell adhesion in vitro. Down-regulation of LFA-1 occurred by (i) posttranscriptional modulation of LFA-1 alpha L-chain RNA soon after acute c-myc induction, and (ii) transcriptional modulation in cells that chronically express c-myc oncogenes. Analogous reductions in LFA-1 expression were detectable in Burkitt lymphoma cells carrying activated c-myc oncogenes. Since LFA-1 is involved in B cell adhesion to cytotoxic T cells, natural killer cells, and vascular endothelium, these results imply functions for c-myc in normal B cell development and lymphomagenesis.
Separation and characterization of saponins with adjuvant activity from Quillaja saponaria Molina cortex. Saponins were purified from Quillaja saponaria Molina bark by silica and reverse phase chromatography. The resulting purified saponins were tested for adjuvant activity in mice. Several distinct saponins, designated QS-7, QS-17, QS-18, and QS-21, were demonstrated to boost antibody levels by 100-fold or more when used in mouse immunizations with the Ag BSA and beef liver cytochrome b5. These purified saponins increased titers in all major IgG subclasses. To determine optimal dose in mice for adjuvant response, QS-7 and QS-21 were tested in a dose-response study in intradermal immunization with BSA in mice; for both of these purified saponins, adjuvant response (determined by stimulation of ELISA titers to BSA) neared maximum at doses of 5 micrograms and was shown to plateau up to the highest dose tested, 80 micrograms. These purified saponins vary considerably in their toxicity, as assessed by lethality in mice; the main component, QS-18, being the most toxic. Saponins QS-7 and QS-21 showed no or very low toxicity in mice, respectively. None of these saponins stimulated production of reaginic antibodies. The monosaccharide composition of these saponins showed similar but distinct compositions with all four containing fucose, xylose, galactose and glucuronic acid. Predominant differences were observed in the quantities of rhamnose, arabinose, and glucose. Monomer m.w. (determined by size exclusion HPLC) were determined to range from 1800 to 2200.
Response by women aged 65-79 to invitation for screening for breast cancer by mammography: a pilot study [published erratum appears in BMJ 1991 Jul 27;303(6796):234] OBJECTIVE--To determine whether there is sufficient benefit to be gained by offering screening for breast cancer with mammography to women aged 65-79, who are not normally invited for screening. DESIGN--Pilot study of women eligible for screening but not for personal invitation. The results of this study were compared with the results of routinely screened younger women (aged 50-64) from the same general practice. SETTING--One group general practice in south Manchester. PATIENTS--The 631 women aged 65-79 on the practice list. A total of 42 (7%) were excluded by the general practitioner, and 22 (4%) invitation letters were returned by the post office. MAIN OUTCOME MEASURES--Response rates to invitation for screening assessed by three indices: crude population coverage ratio, crude invited population coverage ratio, and corrected invited population coverage ratio. RESULTS--344 Patients aged 65-79 (61% of those invited, excluding those who could not be traced) were screened compared with 77% of women aged 50-64. The three response indices were higher for younger women than older: crude population coverage ratio = 66.5%, crude invited population coverage ratio = 69.3%, corrected invited population coverage ratio = 76.8% for women aged 50-64, compared with 54.5%, 58.4%, and 60.7% respectively for women aged 65-79. All four biopsies done in the older women gave positive results, giving a cancer detection rate of 11.6/1000 compared with 4.1/1000 among younger women. CONCLUSIONS--These results show that there is a potential for high attendance at routine screening by older women if they are invited in the same way as younger women. If these results are found elsewhere the costs and benefits of screening older women should be reassessed.
Treatment of condyloma acuminatum with three different interferon-alpha preparations administered parenterally: a double-blind, placebo-controlled trial. One hundred seventy-eight patients were enrolled in a placebo-controlled trial to evaluate three interferon-alpha preparations administered parenterally for the treatment of condyloma acuminatum. When all interferon groups were combined and compared with placebo, interferon recipients had greater rates of complete, 75%, 50%, and 25% lesion resolution than did placebo recipients (P = .21, P = .14, P = .02, and P = .02, respectively). Rates of lesion resolution were higher among women than among men, and women were more likely than men to respond to interferon. Virologic measurements in paired lesion biopsies did not correlate with interferon treatment or disease outcome. Although interferon toxicity was observed frequently, no participant withdrew from the study because of side effects, and dosage alterations were not required. Parenterally administered interferon-alpha is more effective than placebo in treating condyloma acuminatum, although rates of complete response are low. Different regimens, including combination therapy, should be evaluated for treatment of this common sexually transmitted disease.
Prolonged cardiac preservation. Evaluation of the University of Wisconsin preservation solution by comparison with the St. Thomas' Hospital cardioplegic solutions in the rat. The University of Wisconsin solution differs from other types of solutions used for organ preservation because it contains high-energy phosphate precursors (adenosine and phosphate), impermeants (lactobionate and raffinose), an oncotic agent (pentafraction), and antioxidants (allopurinol and glutathione). These components have the potential to enhance the preservation of ATP, reduce intracellular and extracellular edema, and attenuate free-radical-mediated injury. The University of Wisconsin solution has been demonstrated to enhance and extend the preservation of the liver, pancreas, and kidney, but its potential role in the heart remains unproven. We have evaluated the University of Wisconsin solution (Du Pont) by comparing it with the St. Thomas' Hospital cardioplegic solutions No. 1 and No. 2 (Plegisol), which are used in Europe and the United States for routine cardiac surgery and transplantation. For each solution, 10 isolated working rat hearts were arrested by 10 ml of the solution (at 4 degrees C) and then maintained immersed in the same solution for 4 hours at 4 degrees C. Mean recovery of functional indexes (expressed as a percentage of their preischemic control values) after use of the University of Wisconsin solution were as follows: peak aortic pressure, 90.6 +/- 1.0; dP/dt, 71.5 +/- 5.5; aortic flow, 81.6 +/- 4.7; coronary flow, 87.5 +/- 3.5; and cardiac output, 82.6 +/- 3.5. In contrast, the mean recoveries after St. Thomas' Hospital solution No. 1 were as follows: peak aortic pressure, 82.8 +/- 1.3; dP/dt, 49.7 +/- 3.0; aortic flow, 58.4 +/- 5.3; coronary flow, 79.6 +/- 5.9; and cardiac output, 63.0 +/- 4.9. In contrast still, mean recoveries after St. Thomas' Hospital solution No. 2 were as follows: peak aortic pressure, 83.1 +/- 1.2; dP/dt, 40.7 +/- 6.1; aortic flow, 37.0 +/- 5.1; coronary flow, 65.8 +/- 3.6; and cardiac output, 43.1 +/- 5.6. The recovery of all indexes were significantly superior (p less than 0.005) after preservation with University of Wisconsin solution compared with either of the St. Thomas' Hospital solutions.
Death and functional outcome after spontaneous intracerebral hemorrhage. A prospective study of 166 cases using multivariate analysis Using death and functional status as end points, we prospectively analyzed the outcome 6 months after spontaneous intracerebral hemorrhage in 166 patients admitted to an acute-care stroke unit on the first day of their stroke. Seventy-one patients (43%) died, 69 (42%) had a satisfactory outcome, and 26 (16%) had a poor functional outcome. Early (30-day) survival was correlated with morphologic parameters on the initial computed tomogram (hemorrhage size, midline shift, and intraventricular spread of the hemorrhage), while later (6-month) survival was correlated with age. Using logistic regression, we found five independent predictors of satisfactory outcome at 6 months: age, hemorrhage size, intraventricular spread of the hemorrhage, limb paresis, and communication disorders. Of these, age was the most important predictor by far.
Pediatric osteosarcoma: therapeutic strategies, results, and prognostic factors derived from a 10-year experience. Ninety-eight pediatric patients were treated with three separate protocols (Treatment and investigation of Osteosarcoma [TIOS] I, II, and III) and 47 developed recurrent disease (metastases and/or local recurrence). Actuarial overall disease-free survival (hereafter designated survival) was 43%. Over 90% of the patients were treated initially with preoperative intraarterial cisplatin (CDP). Postoperative chemotherapeutic regimens comprised high-dose methotrexate with leucovorin rescue (MTX-CF), Adriamycin [( ADR] doxorubicin; Adria Laboratories, Columbus, OH), and cyclophosphamide. Primary definitive treatment comprised amputation or limb salvage (TIOS I and TIOS III). Patients treated with preoperative CDP and surgery (TIOS I and III) had a 62% survival. Patients in TIOS II refused surgical extirpation; they were treated exclusively with chemotherapy and had a 23% survival. Survival in patients treated with amputation was 55% and limb salvage 58%. Prognostic factors considered significant in relation to development of pulmonary metastases comprised tumor burden (P = .04) and the percentage of tumor necrosis induced by preoperative chemotherapy (P = .01). Histopathologic subtype was marginally significant: chondroblastic was more favorable as opposed to osteoblastic (P = .05). These findings are compared with results and prognostic factors published in the literature.
The interplay of local and distant control in the cure of cervical cancer. From 1978 to 1986, 183 women with cervical cancer received definitive radiation therapy after extraperitoneal surgical staging. Relapse-free rates were strong functions of pelvic lymph node metastases and cervical size. The recurrence distribution consisted of 4% isolated local, 13% isolated distant, and 17% combined local and distant failures. With the assumption of independent local and distant failure probabilities, Suit et al.'s method was extended to assess potential improvement in cure attainable with perfect local and distant control, yielding local (LSA) and distant (DSA) survival advantages of 17% and 28%. Various subsets of clinical stage, cervical size, pelvic node metastases, periaortic metastases, and peritoneal metastases had LSA from 12% to 27% and DSA from 12% to 71%. For any prognostic group, LSA never exceeded DSA, showing that effective systemic therapy would have a greater impact on improving survival than would advances in local and regional tumor control. Therapeutic implications and limitations of the extended LSA-DSA model are discussed. This form of analysis can be used to guide the intensity of local and distant treatment to maximize the cure of the patient with cancer.
Renal artery stenosis in patients with aortic dissection: increased prevalence The authors retrospectively analyzed the prevalence of renal artery stenosis in 63 consecutive patients with aortic dissection who underwent thoracic and abdominal aortography. Ten patients (16%) had renal artery stenosis, five with atherosclerosis and five with fibromuscular lesions. Risk factors for aortic dissection were Marfan disease in nine patients, bicuspid aortic valve in one, and hypertension in 54 (including seven patients with Marfan syndrome). If the patients with Marfan syndrome and the patient with the bicuspid aortic valve are excluded, renal artery stenosis was present in 10 of 53 patients (19%) when the cause of dissection was presumably hypertension. This finding suggests that renovascular hypertension is a greater risk factor for aortic dissection than is essential hypertension. The success of angiotensin converting enzyme inhibitors and percutaneous transluminal renal angioplasty (PTRA) in controlling renovascular hypertension has been proved. In this series, emergent PTRA successfully controlled the hypertension in one patient with a type B dissection, resulting in an excellent clinical outcome. Angiography should be routinely performed on patients with aortic dissections to evaluate for renal artery stenosis.
Familial occurrence of inflammatory bowel disease. BACKGROUND AND METHODS. We assessed the familial occurrence of inflammatory bowel disease in Copenhagen County, where there has been a long-term interest in the epidemiology of such disorders. In 1987 we interviewed 662 patients in whom inflammatory bowel disease had been diagnosed before 1979, asking whether their first- and second-degree relatives had this disorder. Ninety-six percent of the patients (504 with ulcerative colitis and 133 with Crohn's disease) provided adequate information. RESULTS. As compared with the general population, the first-degree relatives of the 637 patients with ulcerative colitis or Crohn's disease had a 10-fold increase in the risk of having the same disease as the patients, after standardization for age and sex. The risk of having the other of the two diseases was also increased, but less so, and the increase in the risk of having Crohn's disease was not significant in the relatives of patients with ulcerative colitis. The risk of ulcerative colitis in first-degree relatives of patients with ulcerative colitis appeared to be virtually independent of the generation to which the first-degree relative belonged and of the sex of the patient and the relative. The risk of ulcerative colitis in first-degree relatives tended to be higher if the disease had been diagnosed in the patient before the age of 50, but the risk seemed to be independent of the current age of the relatives. The prevalence of the same disease as that of the patient (either ulcerative colitis or Crohn's disease) among second-degree relatives was increased; the prevalence of the other disease was not increased. CONCLUSIONS. The 10-fold increase in the familial risk of ulcerative colitis and Crohn's disease strongly suggests that these disorders have a genetic cause.
The genetics of retinoblastoma. Relevance to the patient. The understanding of the molecular biology of human cancer has advanced rapidly in the last decade, in part due to discoveries in the rare, pediatric ocular tumor, retinoblastoma. RB studies have led to recognition of a class of human genes, the tumor suppressor genes, that are critical in the initiation and progression of the malignant process. Mutations in the RB1 gene initiate RB and other specific tumors. They may also contribute to progressive stages of many other malignancies. The protein product of RB1 (p110RB1) is a basic regulator of the cell cycle. In the absence of normal protein, the cell proceeds to the next cell division without the potential to become quiescent. Understanding the genetics of RB has benefited the patients, as the precise identification of the RB1 mutations in families has led to accurate prediction of individuals at risk for RB tumors. It seems unlikely, in the foreseeable future, that direct genetic manipulation of mutant RB1 genes will play a role in therapy, but complete understanding of the function of p110RB1 may eventually allow exploitation of its powerful antiproliferative effect. Other molecular genetic events in addition to RB1 mutations are documented in RB tumors, and may play a critical role in the full malignant phenotype. The oncogene, N-myc, is amplified in some RB tumors and is expressed in normal fetal retina. The cytogenetic abnormality, i(6p), is almost unique to RB tumors. The molecular and tissue-specific roles of these abnormalities are not yet known. Many RB tumors also acquire excessive expression of the cell surface membrane glycoprotein, p170, linked to multidrug resistance, whether or not the RB tumor has been exposed to chemotherapy. We anticipate that ways to avoid or counteract the drug resistance of excessive p170 expression will be developed for other pediatric tumors and eventually will be applied to chemotherapy for RB patients.
Laparoscopic cholecystectomy: report of 82 cases. In our initial experience with 82 patients, laparoscopic cholecystectomy has shown numerous advantages over open cholecystectomy. Both intraoperative blood loss and postoperative need for pain medication have been minimal. Most patients were discharged within 24 to 36 hours and resumed normal activities within 3 to 5 days. The aesthetic aspect is also an obvious advantage, since the laparoscopic procedure avoids disfiguring abdominal scars. Previous abdominal surgery is not a contraindication to attempting this procedure. Based on our experience, laparoscopic cholecystectomy can be done safely on most patients who are candidates for open cholecystectomy, including the elderly, the obese, and those with acute gangrenous cholecystitis.
Protamine-heparin-induced pulmonary hypertension in pigs: effects of treatment with a thromboxane receptor antagonist on hemodynamics and coagulation. Adverse hemodynamic reactions after protamine neutralization of heparin are an infrequent but important clinical problem. Pre-treatment of swine with a thromboxane A2 receptor antagonist has been reported to prevent the pulmonary hypertensive response occasionally seen after protamine reversal of heparin anticoagulation. In the current study, a control group of pigs (n = 9) received intravenous heparin (300 IU/kg), followed after 10 min by a neutralizing dose of protamine (3 mg/kg). A treatment group of pigs (n = 11) was treated identically, except that the thromboxane A2 receptor antagonist L-670596 (2 mg/kg) was infused intravenously 2 min after the protamine infusion. Hemodynamic and coagulation profiles were monitored during these procedures. Pulmonary hypertension developed and reached a peak within 2 min of protamine administration, often at the same time that L-670596 was administered in the treatment group. There was no statistical difference between control and treatment groups' peak pulmonary arterial pressure and peak pulmonary vascular resistance. However, the interval for return of mean pulmonary artery pressure from peak to baseline values was 11.6 +/- 3.1 versus 5.5 +/- 1.9 min (mean +/- SD) for control and treatment groups, respectively (P less than 0.01). Thromboxane B2 plasma concentrations increased in both groups and were correlated with the pulmonary hypertensive response (r = 0.86, P less than 0.01). Platelet aggregation to collagen was inhibited by the thromboxane A2 receptor antagonist (P less than 0.05). Bleeding time was prolonged beyond normal range in 50% of L-670596-treated pigs. All other coagulation tests in both groups returned to baseline after reversal of heparin with protamine and were unaffected by L-670596.
Blood-brain barrier damage in acute multiple sclerosis plaques. An immunocytological study. To investigate blood-barrier leakage of plasma proteins in acute plaques of multiple sclerosis (MS) the authors used immunocytological methods to examine frozen tissue removed at autopsy from recently active cases. Annular patterns of protein-rich leakage were seen which may help to elucidate the patterns observed using gadolinium-enhanced nuclear magnetic resonance imaging. Vessel wall damage was found in all acute plaques examined and this was associated with the intramural deposition of complement on smooth muscle components and with an infiltration of HLA-DR +ve macrophages. In addition, all acute cases examined had small plaques which contained particulate material within macrophages and astrocytes, on which complement and immunoglobulins colocated. Attempts to find similar material in cases of chronic MS, subacute sclerosing panencephalitis and in perivenous encephalomyelitis were unsuccessful. These results suggest that the inflammatory changes in early MS plaques may have some specificity which could be related to the antigens whose presence is inferred by the colocation of complement and immunoglobulin on material within activated macrophages and astrocytes.
Photodynamic therapy to treat tumors of the extrahepatic biliary ducts. A case report. The poor survival rate of patients with extrahepatic bile duct tumors is well documented. Over the course of 4 years, we treated a white woman with diabetes diagnosed with histologically proven adenocarcinoma of the common bile duct with six injections of dihematoporphyrin ether followed by seven photodynamic therapy treatments to the biliary duct. As of July 1989, the patient was still alive, was not jaundiced, and had a Karnofsky performance status of 70. No changes occurred in any blood chemistry value from the time of injection to the time of photodynamic therapy. Of the transient elevations of some blood chemistry values and the white blood cell count, which occurred within 24 to 48 hours after photodynamic therapy, only those of alanine aminotransferase, aspartate aminotransferase, and amylase were significant.
Enhanced mobilization of intracellular Ca2+ induced by halothane in hepatocytes isolated from swine susceptible to malignant hyperthermia. Halothane, in a dose-dependent manner, induced the release of intracellular Ca2+ in hepatocytes prepared from swine. The magnitude of the release induced by halothane was greater for hepatocytes prepared from animals susceptible to malignant hyperthermia (MH) than for those from normal swine. Two different methods were used to ascertain the release of Ca2+ induced by halothane: 1) the release of 45Ca2+ from nonmitochondrial stores of saponin-permeabilized hepatocytes was measured; and 2) changes in luminescence from intact hepatocytes loaded with the Ca2(+)-sensitive photoprotein aequorin were recorded. It was also observed that, although 1,4,5-inositol trisphosphate (IP3), guanosine-5-triphosphate, and arachidonic acid all induced a significant release of 45Ca2+ from permeabilized swine hepatocytes, only the quantities of 45Ca2+ released by IP3 were significantly greater for the hepatocytes prepared from the animals susceptible to MH. These data indicate an abnormal Ca2+ homeostasis in hepatocytes isolated from swine susceptible to MH, which supports the hypothesis that membrane systems from multiple organs may be affected in this genetic disorder.