123rc/medical_text huggingface dataset:
Treatment of infection after total knee arthroplasty by debridement with retention of the components. Thirty-one total knee arthroplasties were followed by infection in twenty-seven patients who were subsequently treated with debridement, retention of the components, and intravenous administration of antibiotics. The results were reviewed retrospectively in an effort to evaluate the function of the prostheses that had been salvaged successfully and to identify the causes of failure of those around which an infection had recurred. At the most recent follow-up (average duration, 8.8 years), infection had recurred around twenty-four (77 per cent) of the thirty-one arthroplasties. Seven knees (23 per cent) remained free of infection. Function remained satisfactory, although revision was subsequently needed in two knees for reasons other than infection. One cause of failure was the duration of the infection before debridement. This averaged twenty-one days for the seven knees in which the prosthetic arthroplasty had been salvaged and thirty-six days for the twenty-four knees in which treatment had failed. Another cause of failure was the type of organism: Staphylococcus aureus had caused the infection in fourteen (58 per cent) of the twenty-four knees in which the treatment failed but in only two of the seven knees in which the prosthetic arthroplasty was salvaged. In addition, eight infections in the first group were resistant to penicillin, whereas both infections in the second group were sensitive to penicillin. The four infections with gram-negative organisms in the series were all in knees in which the treatment failed. All six hinged prostheses that were used failed.
Free and peptide-bound amino acids as indicators of ischemic damage of the rabbit spinal cord. The concentrations of free and peptide-bound amino acids aspartate (Asp), glutamate (Glu), glycine (Gly) and gamma-aminobutyric acid (GABA) were studied following ischemia and recirculation in the ventral and dorsal gray matter of the rabbit spinal cord. No changes in the concentration of amino acids following ten minutes (min) of ischemia and four days of recovery were found. The most significant change after 20 min, and especially 40 min, of ischemia was a decrease in free Asp and GABA levels in both parts of the gray matter. The relatively greater decrease in the concentration of free amino acids in the ventral horns corresponds with the greater morphological damage to this part of spinal cord following ischemia. Following 40 min of ischemia and recirculation decrease in peptide-bound Glu in the ventral horns and Asp and Glu in the dorsal horns was found.
Molecular structure of a major insulin/mitogen-activated 70-kDa S6 protein kinase. The molecular structure of a rat hepatoma 70-kDa insulin/mitogen-stimulated S6 protein kinase, obtained by molecular cloning, is compared to that of a rat homolog of the 85-kDa Xenopus S6 protein kinase alpha; both kinases were cloned from H4 hepatoma cDNA libraries. The 70-kDa S6 kinase (calculated molecular mass of 59,186 Da) exhibits a single catalytic domain that is most closely related in amino acid sequence (56% identity) to the amino-terminal, kinase C-like domain of the rat p85 S6 kinase (calculated molecular mass of 82,695 Da); strong similarity extends through a further 67 residues carboxyl-terminal to the catalytic domain (40% identity), corresponding to a region also conserved among the kinase C family. Outside of this segment of approximately 330 amino acids, the structures of the p70 and p85 S6 kinases diverge substantially. The p70 S6 kinase is known to be activated through serine/threonine phosphorylation by unidentified insulin/mitogen-activated protein kinases. A model for the regulation of p70 S6 protein kinase activity is proposed wherein the low activity of the unphosphorylated enzyme results from the binding of a basic, inhibitory pseudosubstrate site (located carboxyl-terminal to the extended catalytic domain) to an acidic substrate binding region (located amino-terminal to the catalytic domain); substrate binding is thereby prevented. S6 kinase activation requires displacement of this inhibitory segment, which is proposed to occur consequent to its multiple phosphorylation. The putative autoinhibitory segment contains several serine and threonine residues, each followed directly by a proline residue. This motif may prevent autophosphorylation but permit transphosphorylation; two of these serine residues reside in a maturation promoting factor (MPF)/cdc-2 consensus motif. Thus, hormonal regulation of S6 kinase may involve the action of MPF/cdc-2 or protein kinases with related substrate specificity.
Furosemide-131I-hippuran renography after angiotensin-converting enzyme inhibition for the diagnosis of renovascular hypertension. PURPOSE: We have previously demonstrated the greater sensitivity of 131I-hippuran renography than 99mTC-DTPA scintigraphy to diagnose renovascular hypertension (RVH). This study assesses the predictive diagnostic value of furosemide-131I-hippuran renography after angiotensin-converting enzyme (ACE) inhibition in patients with and without RVH. PATIENTS AND METHODS: All patients were investigated at the University of Miami/Jackson Memorial Medical Center. Twenty-eight patients had RVH and 22 did not. Twenty-eight patients had normal or minimally decreased renal function (serum creatinine level 1.5 mg/dL or less) and 22 had renal insufficiency (serum creatinine level 1.8 mg/dL or more). Renography was performed 60 minutes after oral administration of 50 mg captopril or 10 minutes after intravenous injection of 40 micrograms/kg enalaprilat. Forty milligrams of furosemide were administered intravenously 2 minutes after injection of 131I-hippuran. The residual cortical activity (RCA) of 131I-hippuran was measured at 20 minutes. RESULTS: RVH was unlikely when RCA after ACE inhibition was less than 30% of peak cortical activity. Conversely, RVH was present when 131I-hippuran cortical activity steadily increased throughout the test to reach 100% at 20 minutes. In azotemic patients with RCA between 31% and 100%, RVH was differentiated from intrinsic renal disease by obtaining a baseline renogram without ACE inhibition and comparing RCA in that study and RCA after ACE inhibition. If RCA increased (indicating worsening renal function) after ACE inhibition, RVH was likely; whereas, intrinsic renal disease was more likely if RCA remained unchanged or decreased (indicating improved renal function) with ACE inhibition. The test had a specificity of 95% and a sensitivity of 96% in this population. There was a direct correlation between the results of angioplasty or surgery on high blood pressure and the changes in RCA before and after intervention (n = 20). CONCLUSION: Furosemide-131I-hippuran renography with ACE inhibition is highly predictive in identifying patients with RVH.
Introduction of nerve growth factor (NGF) receptors into a medulloblastoma cell line results in expression of high- and low-affinity NGF receptors but not NGF-mediated differentiation. Expression of the cloned human nerve growth factor receptor (NGFR) cDNA in cell lines can generate both high- and low-affinity binding sites. Since the inability to respond appropriately to differentiation factors such as NGF may contribute to determining the malignant phenotype of neuroblastomas, we sought to determine whether the same is true of medulloblastomas. To generate a human central nervous system neuronal cell line that would respond to NGF, we infected the medulloblastoma cell line D283 MED with a defective retrovirus carrying the cDNA coding for the human NGFR. The resultant cells (MED-NGFR) expressed abundant low- and high-affinity NGFRs, and NGF treatment induced a rapid transient increase of c-fos mRNA in the NGFR-expressing cells but not in the parent line or in cells infected with virus lacking the cDNA insert. However, the MED-NGFR cells did not internalize the NGFR at high efficiency, nor did they differentiate in response to NGF. Three important conclusions emerge from this study: (i) internalization of NGFRs is not necessary for some early rapid transcriptional effects of NGF; (ii) an unknown factor(s) that cooperates with the cloned NGFR in allowing high-affinity NGF binding is found in a primitive central nervous system cell line; and (iii) NGFRs introduced into and expressed by D283 MED (i.e., MED-NGFR) cells are partially functional but are unable to induce differentiation in these primitive neuron-like tumor cells, implying that high-efficiency receptor-mediated endocytosis of NGF and its receptor may be a necessary step in the cascade of events leading to NGF-mediated differentiation.
Streptococcus bovis meningitis: report of 2 cases. We describe 2 cases of Streptococcus bovis meningitis and review the 9 cases previously reported. This microorganism is a rare cause of meningitis in which there are no distinctive clinical or laboratory features. The Gram stain of the CSF is usually negative. Ten of the 11 cases had some underlying disease or comorbid condition that predisposed to S bovis infection: gastrointestinal disorder, endocarditis, CSF leak, polymyalgia rheumatica, and mandibular block. Treatment with high-dose penicillin is usually adequate.
Elevation of plasma neuropeptide Y-like immunoreactivity and noradrenaline during myocardial ischaemia in man. Plasma levels of neuropeptide Y-like immunoreactivity (NPY-LI) and noradrenaline were studied for 25 h in 22 patients with acute ischaemic heart disease. On admission, NPY-LI levels were above normal in 16 patients, and 20 patients had increased noradrenaline levels. The initial plasma NPY-LI did not differ between patients with acute myocardial infarction (AMI) and angina pectoris. Initial plasma noradrenaline levels were higher in patients with AMI than in those with angina pectoris. Plasma levels of noradrenaline remained elevated in AMI patients, but decreased towards normal values in patients with angina pectoris. Levels of NPY-LI returned to normal within 25 h in all patients. Tachycardia and left ventricular failure were related to high NPY-LI and noradrenaline levels. A positive correlation was found between noradrenaline and NPY-LI in plasma. It is suggested that neuropeptide Y (NPY), an endogenous vasoconstrictor peptide, should be considered as one of the mediators involved in the cardiovascular response to sympathetic activation induced by myocardial ischaemia.
Regulatory control of the terminal complement proteins at the surface of human endothelial cells: neutralization of a C5b-9 inhibitor by antibody to CD59. Functionally inhibitory antibody to the plasma membrane complement inhibitor CD59 has been used to investigate control of the terminal complement proteins at the endothelial cell surface. Antibodies against purified human erythrocyte CD59 (polyclonal anti-CD59 and monoclonal antibodies [MoAbs] 1F1 and 1F5) were found to bind specifically to monolayers of cultured human umbilical vein endothelial cells, and by Western blotting to recognize an 18- to 21-Kd endothelial protein. When bound to the endothelial monolayer, anti-CD59 (immunoglobulin G or Fab fragment) potentiated membrane pore formation induced upon C9 binding to C5b-8, and augmented the C5b-9-induced cellular responses, including stimulated secretion of von Willebrand factor and expression of catalytic surface for the prothrombinase enzyme complex. Although potentiating endothelial responses to the terminal complement proteins, anti-CD59 had no effect on the response of these cells to stimulation by histamine. Taken together, these data suggest that human endothelial cells express the CD59 cell surface inhibitor of the terminal complement proteins, which serves to protect these cells from pore-forming and cell-stimulatory effects of the C5b-9 complex. These data also suggest that the inactivation or deletion of this cell surface regulatory molecule would increase the likelihood for procoagulant changes in endothelium exposed to complement activation in plasma.
Effect of hydralazine on the mesenteric vasculature of hypertensive rats. To test whether structural alterations observed in the mesenteric vasculature of Wistar-Kyoto spontaneously hypertensive rats (SHR) were dependent on the presence of hypertension, male SHR and Wistar-Kyoto normotensive (WKY) rats were treated in utero and postnatally with hydralazine up to 28 weeks of age. Treated SHR, WKY, and untreated WKY rats had comparable blood pressures that were less than those of untreated SHR. Treatment altered the dimensions of the superior mesenteric, intermediate-sized, and small arteries of the mesenteric vasculature. In the case of the superior mesenteric artery and intermediate vessels, hydralazine treatment increased the lumen and medial cross-sectional areas of the arteries in WKY rats and slightly decreased both parameters in SHR. Within the small arteries, treatment significantly increased the lumen size in SHR but not WKY rats and had no significant effect on the media of the vessels. Despite the above alterations, the media-to-lumen cross-sectional area ratios remained significantly elevated in SHR over WKY rats in both the treated and control groups of animals within all classes of arteries. The results indicate that there is an inherent increase in the quantity of media surrounding the arteries of SHR when compared with WKY rats that cannot be abolished by normalizing the blood pressure in utero and postnatally with hydralazine treatment. In SHR, such changes persist not only in arteries that exhibit an increase in the media-to-lumen ratio before hypertension but also in the superior mesenteric artery in which an increase in the ratio occurs after hypertension development.
Analysis of brain and cerebrospinal fluid volumes with MR imaging: impact on PET data correction for atrophy. Part II. Aging and Alzheimer dementia A new, computerized segmentation technique, in which magnetic resonance (MR) imaging produces accurate volumetric measurements of brain and cerebrospinal fluid (CSF) without the limitations of computed tomography, was used in a retrospective analysis of digitized T2-weighted MR images of 16 healthy elderly control subjects and 16 patients with Alzheimer dementia. Ventricular and extraventricular CSF was quantified, and the effects of aging were studied; in both groups, the atrophy measurement was used to correct metabolic values obtained with positron emission tomography. Patients with Alzheimer dementia had higher total CSF; extraventricular, total ventricular, and third ventricular CSF volumes (49%, 37%, 99%, and 74%, respectively); and 7% lower brain volumes than the control group. The patients also showed a more marked decline in brain volumes and a greater increase in CSF volumes with advancing age than the control group. They had a 25.0% increase in corrected whole-brain metabolic rates; the control group had only a 15.8% increase. The use of this technique may provide a basis for further studies of aging and dementia, including regional volume analysis.
Gallbladder surgery following cholecystlithotripsy: suggested guidelines for treatment Twenty-three of 229 symptomatic patients undergoing cholecystlithotripsy underwent surgical intervention: 22 of the patients had cholecystectomy performed (five also undergoing choledochotomy) and one patient had a cholecystostomy. Of these 23 patients, five were lithotripsy failures, five developed acute pancreatitis, one had acute cholecystitis, and one had cholangitis. One patient had her gallbladder removed incidentally at the time of surgery for a bleeding gastric ulcer. Ten patients underwent surgery for recurrent biliary pain, probably related to fragment passage via the cystic duct. We suggest that up to 16 of these 23 patients did not necessarily require cholecystectomy, i.e. five patients with pancreatitis, one patient with cholangitis and ten patients with recurrent biliary colic. Conservative and/or endoscopic management may be successful in the first instance to allow further treatment with lithotripsy in the majority of patients. If, however, the expertise to perform endoscopic sphincterotomy is not available or the patient declines further lithotripsy, then resort to surgery may be necessary. We propose that it is the responsibility of the management team in charge of the lithotripsy unit to inform both the patient and the referring clinicians of the possible side-effects and outcome of treatment in an attempt to avoid unnecessary surgical procedures.
Needs and recommendations for behavior research in the prevention and early detection of cancer. Because life-style patterns affect many cancer risks, research on health-risk behavior and behavior change is critical to cancer prevention. This report recommends priorities for the next decade of psychosocial research on cancer prevention and detection. The leading priority for future research is to fill gaps in basic knowledge left by the rush to intervention and outcome studies. Such research must be theoretically driven and should aim to develop broad principles applicable to diverse health behaviors. Studies that include relevant process data on various stages of behavior change are considered more desirable than simple outcome studies. Epidemiologic investigations should be expanded to include measures of relevant behaviors, so that their impact on clinical outcomes might be established. More research is needed on lay perception of health risks and on individual and health-system barriers to effective cancer prevention and detection. Studies that address the needs of minority and underprivileged populations are crucial. Funding agencies' narrow categorical mandates impede interdisciplinary research on multiple risk factors and their interactions; these boundaries must be relaxed to promote such approaches. Funding agencies should also consider basic research as a long-term investment towards the development of effective interventions.
Total hip arthroplasty with cement. A long-term radiographic analysis in patients who are older than fifty and younger than fifty years. The long-term performance of a total of 712 Charnley and STH prostheses was evaluated as a function of the patient's age (older than fifty years or younger than fifty years) and of the underlying disease (osteoarthrosis, rheumatoid arthritis, or avascular necrosis). In patients who were older than fifty years, there were lower incidences of continuous cement-bone radiolucency about the acetabular component (p = 0.04), wear of the polyethylene acetabular cup (p = 0.03), and resorption of the calcar (p = 0.03). However, larger percentages of younger patients had rheumatoid arthritis or avascular necrosis. In the cohort of patients who had osteoarthrosis, the performance of the prosthesis did not differ significantly between older and younger patients; therefore we attributed the differences that were observed to the disease--that is, to rheumatoid arthritis or avascular necrosis.
Multimodal therapy for the management of primary, nonmetastatic Ewing's sarcoma of bone: a long-term follow-up of the First Intergroup study. A total of 342 previously untreated eligible children were entered into the first Intergroup Ewing's Sarcoma Study (IESS) between May 1973 and November 1978. In group I institutions, patients were randomized between treatment 1 (radiotherapy to primary lesion plus cyclophosphamide, vincristine, dactinomycin, and Adriamycin [doxorubicin; Adria Laboratories, Columbus, OH] [VAC plus ADR]) or treatment 2 (same as treatment 1 without ADR), and group II institutions randomized patients between treatment 2 or treatment 3 (same as treatment 2 plus bilateral pulmonary radiotherapy [VAC plus BPR]). The percentages of patients relapse-free and surviving (RFS) at 5 years for treatments 1, 2, and 3 were 60%, 24%, and 44%, respectively. There was strong statistical evidence of a significant advantage in RFS for treatment 1 (VAC plus ADR) versus 2 (VAC alone) (P less than .001) and 3 (P less than .05) and also of treatment 3 versus 2 (P less than .001). Similar significant results were observed with respect to overall survival. Patients with disease at pelvic sites have significantly poorer survival at 5 years than those with disease at nonpelvic sites (34% v 57%; P less than .001). Among pelvic cases, there was no evidence of differing survival by treatment (P = .81), but among nonpelvic cases, there was strong evidence of differing survival by treatment (P less than .001). The overall percentage of patients developing metastatic disease was 44%; the percentages by treatments 1, 2, and 3 were 30%, 72%, and 42%, respectively. The overall incidence of local recurrence was 15%, and there was no evidence that local recurrence rate differed by treatment. Patient characteristics related to prognosis, both with respect to RFS and overall survival experience, were primary site (nonpelvic patients were most favorable) and patient age (younger patients were more favorable).
Radial tunnel syndrome. An investigation of compression neuropathy as a possible cause. Conventional electromyographic and nerve-conduction studies usually do not show abnormalities in patients who have a clinical diagnosis of radial tunnel syndrome. Therefore, posterior interosseous nerve-conduction measurements were performed during forced supination in patients who had this syndrome. Only one of sixteen patients had a major increase in latency. Our data do not support the hypothesis that the signs and symptoms in most patients who have a diagnosis of radial tunnel syndrome are caused by compression of the posterior interosseous nerve.
Venomous snakebite in eastern Ecuador. Treatment outcome of 294 hospitalized victims of snakebite injuries in Eastern Ecuador are reported, documenting high rates of morbidity and mortality. One or more major complications occurred in 25% of patients. Complications included blood loss severe enough to require transfusion (29 patients), abscess (26 patients), intracranial hemorrhage (15 patients) and major tissue loss (10 patients). Sixteen patients died, yielding a mortality rate of 5.4%. Death resulted from intracranial hemorrhage in 12 patients and from sequelae of hypovolemic shock in 4 patients.
Detrusor hyper-reflexia as a factor in spontaneous perforation of augmentation cystoplasty for neuropathic bladder. In a series of 30 children undergoing cystoplasty for neuropathic bladder, 14 had a combination of a competent sphincteric mechanism and detrusor hyper-reflexia. All 3 cases of spontaneous perforation of the augmentation occurred within this latter group and it is postulated that excessive intravesical pressure due to high pressure hyper-reflexia was the causal factor. Strategies to reduce the risk of perforation are discussed.
Radiation therapy of laryngeal cancer: a twenty year experience. This paper reviews a 20 year experience of radiation treatment of 286 laryngeal cancers and presents results with a minimum five year follow-up. All cases presented had glottic or supraglottic squamous cell carcinomas with no clinical evidence of nodal metastasis. A policy of primary radiotherapy with surgery for salvage of treatment failures, produced control of primary disease and prevention of metastases superior to most other regimes documented in the literature.