123rc/medical_text huggingface dataset:
Adult T-cell leukaemia/lymphoma in Brazil and its relation to HTLV-I In a series of fourteen patients with adult T-cell lymphoma-leukaemia (ATLL) in Brazil the main features were lymphadenopathy, hepatosplenomegaly, hypercalcaemia, and high leucocyte counts, with abnormal lymphoid cells which had irregular nuclei. The series included the youngest patient with ATLL so far (18 months). Analysis with monoclonal antibodies showed a mature T-cell phenotype (CD4+, CD8-). Antibodies to HTLV-I and/or integration of HTLV-I proviral DNA were found in eleven patients. In the other three HTLV-I DNA could not be demonstrated even by means of the polymerase chain reaction; they therefore had HTLV-I-negative ATLL. This report of ATLL in Brazil corroborates serological reports that HTLV-I may be endemic in some parts of that country. Follow-up studies are required to identify precisely the main route of transmission of HTLV-I in South America and the risk factors for the development of ATLL in carriers.
Deep venous thrombosis: longitudinal study with duplex US. Forty-nine patients with deep venous thrombosis (DVT) of the lower limb were studied with repeated duplex ultrasound (US) for at least 1 year or until the vein became normal at US. Standard anticoagulant therapy was given for 3 months. In 36 patients, the veins became normal within 1 year. The likelihood of normalization increased if the lesion was located in only one site, if the pelvic veins were unaffected, if the affected leg was the left one, if the initial clot was nonocclusive, if there was no history of DVT, and if the symptoms had lasted less than than 24 hours. The average time before normalization was shorter if the symptoms had lasted less than 24 hours, that is, 11 weeks versus 25 weeks (P less than .02). The rate of sequelae at 1 year was lower if the US scan was normal or showed regression at 3 months, 6% versus 83% (P less than .00005).
Management of infants at risk for occult bacteremia: a decision analysis. Because febrile infants with no obvious source of bacterial infection may have bacteremia, and because bacteremia is difficult to diagnose on clinical grounds, we used decision analysis to evaluate whether such infants should be treated with antibiotics, tested further, or sent home. Using a simple decision tree, we found that the decision to give empiric antibiotic treatment is the decision of choice. The difference in quality-adjusted life expectancy between the "best" and "worst" decisions was only 11 days. However, this difference translated to prevention of death or permanent disability in 60 cases per 100,000 febrile children. Further, empiric treatment remained the best management alternative unless the probability of bacteremia was less than 1.4% (less than any published prevalence), or the efficacy of treatment was less than 21%. Our analysis demonstrated that a test with far greater sensitivity than leukocyte count or other tests currently in use is needed to justify testing rather than treating empirically. Further, an enormous patient population would be needed to find a difference of both clinical and statistical significance between treated and untreated patients in a controlled trial. In the absence of such trials, we recommend blood culture and empiric antibiotic treatment of all infants at risk for occult bacteremia.
Airway luminal liquid. Sources and role as an amplifier of bronchoconstriction. The release of mediators from inflammatory cells into the airway lumen can initiate a series of events leading to airway obstruction, particularly smooth muscle contraction and alteration of endothelial and epithelial permeability leading to mucosal edema and subsequent influx of liquid into the airway lumen. In this report we briefly review the effects of several inflammatory mediators, including eicosanoids, platelet-activating factor, and histamine, as well as the effects of plasma proteins and tachykinins that may be secondarily released because of the presence of inflammatory mediators on endothelial and epithelial permeability. We then consider physical mechanisms whereby the resulting airway luminal liquid could amplify the response of an airway previously constricted because of smooth muscle contraction. Specifically, liquid in the interstices between epithelial projections that are formed during muscular contraction could amplify the degree of luminal compromise by (1) further decreasing luminal cross-sectional area by occupying space, and (2) providing an additional source of inward recoil because of the surface tension of the air-liquid interface.
Defective oral tolerance promotes nephritogenesis in experimental IgA nephropathy induced by oral immunization. Oral tolerance, an important feature of the mucosal immune system, appears to protect against immune-mediated disease by blunting production of systemic IgG and IgM antibody directed toward immunogens chronically present at mucosal surfaces. In this study, we explored the role of oral tolerance and mucosal immunoregulation in an experimental model of IgA nephropathy (IgAN), an important form of nephritis in humans. Cyclophosphamide and estradiol were used to inhibit the expression of oral tolerance, which otherwise develops after chronic oral presentation of Ag. BALB/c mice given drinking water containing 0.1% bovine gamma globulin (BGG) continuously for 14 wk were randomly assigned to groups given either 2 mg of cyclophosphamide i.p., 2 mg of estradiol s.c. or both drugs. Groups of control mice received neither BGG nor drugs. In three separate experiments, a low percentage of saline-treated orally immunized mice had microscopic hematuria (0 to 20%), as did nonimmunized controls (0 to 20%). However, 58 to 83% of mice given estradiol and/or cyclophosphamide at appropriate times developed significant hematuria. If drugs were given at suboptimal times, only 25 to 56% of mice developed hematuria. Drug-treated immunized mice also had more serum IgG and IgM anti-BGG antibodies than control and saline groups. Immunofluorescence showed significantly more glomerular deposits of IgG, IgM, and C3 in drug-treated immunized mice compared to saline-treated immunized and normal untreated control mice. Hematuria and glomerular deposits of IgG, IgM, and C3 paralleled serum IgG and IgM antibody. All immunized mice showed significant mesangial IgA and BGG deposits and there were no differences in such deposits between saline- and drug-treated immunized mice. We suggest that blunting of oral tolerance with promotion of systemic IgG and IgM antibody production leads to nephritis in chronically orally immunized mice and that glomerular immune complexes containing IgG and/or IgM promote complement deposition and hematuria in IgAN. Analogous defects in oral (or more generally mucosal) tolerance could play a role in the genesis of symptomatic human IgAN.
Clinical significance of colonic fermentation. Recent evidence of the potential benefits of short chain fatty acids has prompted renewed interest in the area of human colonic fermentation. This paper reviews the clinical and metabolic consequences of colonic fermentation.
Renal cell carcinoma vs. renal oncocytoma. Report of a case with overlap features and review of the literature Although the salient features of renal oncocytomas and renal cell carcinomas have been discussed in the recent literature, renal masses with features of both entities will present diagnostic difficulty, especially when the cells are diffusely eosinophilic on microscopic examination. A case of a firm, tan, rounded mass replacing the lower pole of the kidney is discussed. The final diagnosis of renal cell carcinoma, granular cell type, was made after multiple sections of the tumor were examined, and after electron microscopy was performed. A thorough search by light microscopy should be made for clear cell foci, necrosis, mitotic activity, and vascular or capsular invasion, features generally accepted as pathognomonic for renal cell carcinoma. Cellular and especially nuclear pleomorphism is typically focal or mild in renal oncocytomas. True oncocytic tumors will be packed with mitochondria on electron microscopy; however, granular renal cell carcinomas will contain mitochondria as well as other cellular organelles, lipid, and glycogen. Electron microscopy should be performed on tumors suspected of being oncocytomas because eosinophilia on hematoxylin and eosin stain, as demonstrated by this case, is not a predictable measure of mitochondria content. Immunoperoxidase staining for vimentin in oncocytomas has recently been shown to be negative, and may offer a method of ruling out oncocytoma in vimentin-positive tumors, pending further studies.
Clinical prognostic factors in patients with posterior uveal malignant melanoma. The authors evaluated the prognostic value of clinically assessed variables for predicting length of survival until death from metastatic disease in 237 patient with a primary choroidal or ciliary body melanoma. Using multivariate Cox proportional hazards modeling, the authors identified the largest linear basal tumor diameter (mm), estimated by indirect ophthalmoscopy and fundus drawing, the location of the anterior margin of the tumor relative to the ocular equator and ora serrata, and the age of the patient at the time of treatment as the best combination of the clinically assessed variables for predicting survival. For each patient in this group, the authors computed a prognostic index based on the best multivariate Cox model. They showed that patients with low, intermediate, and high values of prognostic index had low, intermediate, and high melanoma-related mortality rates, respectively, during the first 5 to 8 posttreatment years. These results suggest that: (1) clinically assessed variables evaluated according to a standardized protocol are useful for predicting the survival of treated patients with posterior uveal melanoma and (2) ophthalmologists who assess potential clinical prognostic variables consistently may identify subgroups of patients with comparable mortality risk on the basis of noninvasive testing.
Longitudinal dissociation of atrioventricular accessory pathways. Unusual properties of atrioventricular (AV) accessory pathways were found during electrophysiologic investigations in four patients (three men and one woman). Anterograde longitudinal dissociation of the accessory pathway was observed in two patients and retrograde longitudinal dissociation in two others. Two patients had an accessory pathway with a slow conduction time, one in anterograde direction and one in retrograde direction. These observations further expand our knowledge of the spectrum of electrophysiologic properties of accessory AV pathways.
Decreased ventilation and hypoxic ventilatory responsiveness are not reversed by naloxone in Lhasa residents with chronic mountain sickness. Persons with chronic mountain sickness (CMS) hypoventilate and are more hypoxemic than normal individuals, but the cause of the hypoventilation is unclear. Studies of 14 patients with CMS and 11 healthy age-matched control subjects residing in Lhasa, Tibet, China (3,658 m) were conducted to test the hypothesis that hypoventilation, blunted hypoxic ventilatory responsiveness (HVR), and hypoxic ventilatory depression of CMS were due to increased endogenous opioid production. Patients with CMS compared with control subjects exhibited hypoventilation (end-tidal carbon dioxide pressure [PETCO2] = 36.6 +/- 1.0 versus 31.5 +/- 0.5 mm Hg, p less than 0.05), lower tidal volume (VT = 0.54 +/- 0.02 versus 0.61 +/- 0.02 ml BTPS, p less than 0.05), blunted HVR (shape parameter A = 17 +/- 8 versus 114 +/- 22 mm Hg/L BTPS/min, p less than 0.05), and a depressant effect of ambient hypoxia on ventilation (delta PETCO2 with acute hyperoxia = -3.5 +/- 0.5 versus -1.0 +/- 0.6 mm Hg, p less than 0.05). Reduced forced expiratory volume in 1 s to vital capacity ratios (FEV1/VC) and a higher proportion of cigarette smokers in the group of patients with CMS compared with control subjects suggested that at least some patients with CMS had mild airway obstructive lung disease. Naloxone infusion (0.14 mg/kg) to six patients with CMS did not change resting VT, PETCO2, HVR, or SaO2.
Rett syndrome: findings suggesting axonopathy and mitochondrial abnormalities. We report the histopathologic findings of 3 sural nerve biopsies and 1 muscle biopsy from 3 patients with Rett syndrome. The 3 sural nerve biopsies demonstrated a few ultrastructural abnormalities, including the presence of many Pi-granules and mitochondrial changes in the cytoplasm of Schwann cells, occasional bands of Bungner and onion-bulb formations, and mitochondrial alterations in myelinated axons. Morphometric analysis disclosed reduction in the number of large myelinated fibers with normal densities in comparison to those of an age-matched normal control. Light microscopic examination of the biopsied muscle from a 6-year-old patient with Rett syndrome revealed the existence of many small, dark, angulated fibers with NADH-TR staining. Ultrastructural investigation of the muscle confirmed the presence of the dumbbell-shaped mitochondria. Peripheral nerve involvement and the possibility of mitochondrial abnormalities in Rett syndrome were suggested by the results.
Respiratory muscle involvement in nemaline myopathy. A boy who had experienced generalized muscle weakness and hypotonia since early infancy was diagnosed as having nemaline myopathy on the basis of muscle biopsy at 3 years of age. At 8 years of age, he developed severe respiratory failure and required respiratory support during sleep. Because of recurrent pneumothorax, he underwent thoracic surgery, at which time biopsy specimens were obtained from the respiratory and truncal muscles. The histologic findings of the respiratory muscles included marked variation in fiber size with a notable increase in fibrous tissue, type 2 fiber deficiency, elevated acid phosphatase activity, and a disorganized intermyofibrillar network. The findings from the truncal muscles were similar to those of the biceps brachii muscle: little variation in fiber size, numerous nemaline bodies in all fibers, and type 1 fiber predominance. The preferential damage to the respiratory muscles was probably responsible for the sudden onset of severe respiratory failure.
The prognostic value of image analysis in ovarian cancer. Histologic grading is very important for treatment decisions in ovarian cancer. All grading systems contain a significant subjective component, which could be reduced by including objective measurements into the diagnostic decision. Image analysis was used to determine nuclear area and ploidy distributions in 42 patients with epithelial ovarian cancer, and the results were related to tumor grade and clinical outcome. The mean nuclear area, mean optical density, number of hyperploid cells, and the standard deviation between measurements were significantly higher in Grade 2 and 3 tumors compared with Grade 1 tumors, in rapidly progressive tumors compared with less aggressive malignancies, and in recurrent tumors compared with primary lesions. The number of nuclei with very high DNA content was found to be of prognostic importance. Image analysis thus provides additional prognostic information in epithelial ovarian cancer.
The prognostic significance of CA 125 half-life in patients with ovarian cancer who have received primary chemotherapy after surgical cytoreduction. Fifty-four patients with advanced epithelial ovarian cancer were monitored with serial serum CA 125 levels after surgical cytoreduction and during multi-agent chemotherapy with cisplatin-containing regimens. CA 125 half-life of less than 20 days was associated with prolonged overall survival (p less than 0.015). In those patients who eventually were found to be disease-free at surgical surveillance procedures, normalization of serum CA 125 levels to less than 35 U/ml within 65 days of primary operation also suggested an improved survival (p less than 0.059).
How American oncologists treat breast cancer: an assessment of the influence of clinical trials. The present study was designed to assess the preferred methods of treatment of breast cancer by American oncologists, and the impact of clinical trials on their practice. We mailed 465 questionnaires to surgical, radiation, or medical oncologists. The questionnaire described five hypothetic patients with breast cancer, and respondents were asked to select their preferred treatment for each patient. For primary breast cancer, most physicians would offer the choice of local excision followed by radiation therapy or modified radical mastectomy. About 80% of physicians would prescribe adjuvant chemotherapy for a premenopausal woman with estrogen receptor-negative, axillary node negative breast cancer, and for a postmenopausal woman with estrogen receptor-negative, node-positive disease. This policy was favored by male and female physicians of each specialty. Almost all respondents would treat a young woman with inflammatory breast cancer with initial chemotherapy followed by radiation and/or surgery, and about 60% would recommend chemotherapy to a postmenopausal patient with estrogen receptor-negative disease and minimally symptomatic bone metastases. Clinical trials have compared treatment strategies that could be applied to patients described in our questionnaire. Preferred treatments for primary breast cancer, and for inflammatory breast cancer are supported by the results of clinical trials. Recommendation of adjuvant chemotherapy for node-negative breast cancer is not based on a consistent demonstration of improvement in survival, although randomized trials with short follow-up have shown delay to recurrence. Recommendation of adjuvant chemotherapy for a postmenopausal woman with node-positive breast cancer is contrary to the results of large randomized controlled trials (and to a meta-analysis), which have shown that this policy does not lead to improved survival. Our report suggests that even large randomized clinical trials may have a minimal impact on practice if their results run counter to belief in the value of the treatment.
Metabolic bone disease in lumbar pseudarthrosis. Pseudarthrosis occurs in many patients who undergo lumbar spine fusion and it has been suggested that abnormalities of bone metabolism contribute to it. The authors evaluated 47 patients with pseudarthrosis for metabolic bone disease. Symptomatic patients with pseudarthrosis underwent metabolic bone evaluation. Abnormal results of laboratory tests were found in 7 patients (14.9%): 3 low or borderline 1,25 dihydroxy vitamin D3, 2 elevated 24-hour urine calcium, and 2 low serum testosterone. None of these abnormalities correlated with other clinical findings. Bone density was low in 14 of 24 patients in whom it was measured. Low values did not correlate with smoking or abnormal laboratory values. Metabolic bone abnormalities do not appear to play a frequent or significant role in pseudarthrosis after attempted lumbar spine fusion.
Comparison of coronary angiographic features and oral dipyridamole thallium 201 tomography. Coronary angiography and left ventriculography is commonly used to identify those patients with incomplete infarctions and therefore, a need for revascularization. The authors compared coronary angiography and left ventriculography with thallium 201 tomography using oral dipyridamole to identify patients with potential ischemia in the infarct zone indicating viable tissue. Forty-five patients (37 men, 8 women) with acute myocardial infarctions (29 anterior, 16 inferior) who received intravenous thrombolytic therapy were studied. On the basis of the left ventriculograms, only 16 patients were judged to have residual function in the infarct zone. Six of these patients had no thallium redistribution in the infarct zone, indicating lack of residual ischemia. Of the 29 patients with no residual function in the infarct zone, 18 had redistribution in the infarct zone, suggesting residual ischemic myocardium and thus viable tissue. Among the 32 patients with open infarct vessels, 15 had no redistribution in the infarct zone, but of the remaining 13 patients with occluded infarct vessels, 9 had redistribution in the infarct zone indicating residual ischemia and thus viable tissue. The authors' data suggest that neither wall motion analysis by left ventriculography nor the angiographic status of the infarct vessel identifies those patients with residual ischemia as evidenced by thallium tomography using oral dipyridamole.
Ultrasound and ultrasound-guided fine needle aspiration biopsy of supraclavicular lymph nodes in patients with esophageal carcinoma. The use of ultrasound combined with ultrasound-guided fine-needle aspiration biopsy (UGFAB) of supraclavicular lymph nodes in the pretreatment staging of 37 patients with squamous cell carcinoma of the esophagus is described. All patients underwent computed tomography (CT) scans of the chest and the abdomen and ultrasound of the abdomen and supraclavicular regions. Supraclavicular lymph node metastases (Stage IV disease according to the tumor nodes metastasis [TNM] classification) were cytologically diagnosed in seven (18.9%) of the 37 patients. In two of these patients, no other metastases were found. In the other five patients, UGFAB replaced more invasive diagnostic procedures. Due to their superficial location, ultrasound and UGFAB of the supraclavicular lymph nodes was relatively simple to perform, and contributed to an improved staging of squamous cell carcinoma of the esophagus.
Reversal of colchicine-induced mitotic arrest in Chinese hamster cells with a colchicine-specific monoclonal antibody. The ability of a high-affinity colchicine-binding monoclonal antibody to reverse the effects of colchicine on Chinese hamster ovary cells was investigated. Using flow cytometry, a complete mitotic blockade was demonstrated after 16 hours with 2.5 x 10(-7) mol/l (molar) colchicine. Colchicine-induced changes were reversible when equimolar antibody was added simultaneously with or up to 6 hours after colchicine. With further delay in addition of antibody, a progressive irreversible increase in mitotic blockade and increase in mean cell size was observed. Prolonged colchicine exposure, without antibody reversal, led to polyploidy and structural chromosome breakage. Early antibody reversal restored cells to the diploid state, whereas delayed reversal resulted in a time-dependent increase in polyploidy. Colchicine-induced polyploidy and chromosomal aberrations may be the basis for both colchicine toxicity and the time-dependent increase in irreversibility of colchicine effects.
In vivo biological effects of stereotactic radiosurgery: a primate model. Single-fraction, closed skull, small-volume irradiation (radiosurgery) of intact intracranial structures requires accurate knowledge of radiation tolerance. We have developed a baboon model to assess the in vivo destructive radiobiological effects of stereotactic radiosurgery. Three baboons received a single-fraction, 150-Gy lesion of the caudate nucleus, the thalamus, or the pons using the 8-mm diameter collimator of the gamma unit. Serial standard neurodiagnostic tests (neurological examination, computed tomographic scan, magnetic resonance imaging, stable xenon-enhanced computed tomographic scan of cerebral blood flow, somatosensory and brain stem evoked potentials, and myelin basic protein levels of cerebrospinal fluid) were compared with preoperative studies. Magnetic resonance imaging revealed the development of a lesion at the target site between 45 and 60 days after irradiation. Deterioration of the brain stem evoked potentials preceded imaging changes when the lesion encroached on auditory pathways. Myelin basic protein levels increased subsequent to imaging changes. Postmortem neuropathological examination confirmed a well-demarcated radionecrosis of the target volume. The baboon model appears to be an excellent method to study the in vivo biological effects of radiosurgery.