shukoor65/lab-rag-model huggingface dataset:
Mediastinal nodal involvement and the prognosis of non-small cell lung cancer. We evaluated the effect of mediastinal lymph node metastasis on survival in 233 non-small cell lung cancer patients (N2 disease in 199 patients and N3 disease in 34 patients). Of the 199 patients with N2 disease, 144 underwent curative resection. The five-year survival rate of these 144 patients was 20.3 percent, which was significantly better than that of either the noncuratively resected N2 group or the N3 group. Nodal metastases in the curatively resected patients involved superior and inferior mediastinum irrespective of the location of the primary tumor. Patients with right-sided N2 lesions and metastases to the superior mediastinum had a worse survival than those with metastases to the inferior mediastinum. In contrast, patients with left-sided N2 lesions metastasizing to the inferior mediastinum had a significantly worse survival than those with lesions metastasizing to the superior mediastinum. Patients with single-level metastases had a significantly better survival rate than those with multilevel metastases. Subcarinal nodal involvement had an unfavorable effect in case of single-level metastasis, but did not affect the survival in cases of multilevel metastases. Our present study indicated that the survival of patients with N2 disease was affected by the operative radicality, by the number of levels of metastases, and also by the location of the nodal involvement. It seems appropriate that extensive mediastinal dissection should be performed irrespective of the location of the primary tumor.
Expression of a partially deleted gene of human type II procollagen (COL2A1) in transgenic mice produces a chondrodysplasia. A minigene version of the human gene for type II procollagen (COL2A1) was prepared that lacked a large central region containing 12 of the 52 exons and therefore 291 of the 1523 codons of the gene. The construct was modeled after sporadic in-frame deletions of collagen genes that cause synthesis of shortened pro alpha chains that associate with normal pro alpha chains and thereby cause degradation of the shortened and normal pro alpha chains through a process called procollagen suicide. The gene construct was used to prepare five lines of transgenic mice expressing the minigene. A large proportion of the mice expressing the minigene developed a phenotype of a chondrodysplasia with dwarfism, short and thick limbs, a short snout, a cranial bulge, a cleft palate, and delayed mineralization of bone. A number of mice died shortly after birth. Microscopic examination of cartilage revealed decreased density and organization of collagen fibrils. In cultured chondrocytes from the transgenic mice, the minigene was expressed as shortened pro alpha 1(II) chains that were disulfide-linked to normal mouse pro alpha 1(II) chains. Therefore, the phenotype is probably explained by depletion of the endogenous mouse type II procollagen through the phenomenon of procollagen suicide.
Evaluation and treatment of blunt renal trauma. We examined retrospectively the records of 126 patients with blunt renal trauma to determine the criteria for radiological investigations and the imaging study of choice. Of the 3,993 patients admitted to our regional trauma unit during the last 13 years 126 (3.1%) had blunt renal trauma. Mean patient age was 32 years (range 13 to 87 years) and the male-to-female ratio was 3:1. Mean followup was 7 months (median 4 months). Of the patients 72% had a minor renal injury, 17% had a moderate injury and 11% had a major renal injury. Treatment was conservative in 114 patients, while 9 underwent a genitourinary operation. Results were excellent in 87% of the patients and good in 8%, while 5% failed treatment. All patients who had microscopic hematuria without shock had minor injuries. Excretory urograms (IVPs) were normal in 74% and 39% of the patients when performed for minor and moderate renal injuries, respectively. Computerized tomography (CT) was abnormal in all cases when performed, and was more sensitive and specific than an IVP. Therefore, the majority of patients with blunt renal trauma can be treated conservatively with an excellent result. Furthermore, radiological investigations are not needed in those with microscopic hematuria and no shock. When radiological investigations are indicated a CT scan is the imaging study of choice.
Role of high total protein in gallbladder bile in the formation of cholesterol gallstones. While it is generally accepted that cholesterol supersaturation of bile is of key importance in the rapid formation of cholesterol crystals, the role of total biliary protein and pH in the pathogenesis of cholesterol gallstones is less well understood. The relation of cholesterol saturation, total protein, and pH was studied in 73 gallbladder bile samples with and 35 gallbladder bile samples without cholesterol crystals. In samples containing crystals, a trend to higher values of cholesterol and to a higher cholesterol saturation index was observed. However, significantly (P = 0.02) higher concentrations of total protein were found in samples with crystals [0.80 +/- 0.40 g/dL (8.0 +/- 4.0 g/L)] than in samples without crystals [0.63 +/- 0.26 g/dL (6.3 +/- 2.6 g/L)]. Moreover, of 22 bile samples with total protein concentrations greater than 10.0 g/L, cholesterol crystals were detected in all but 2. Total lipids, bile acids, phospholipids, and pH values were not significantly different in the two groups of bile samples. It was concluded that high biliary protein concentrations are frequently associated with cholesterol crystals and may, therefore, be a possible risk factor in the pathogenesis of cholesterol gallstones.
In vivo measurements of relative motion between an uncemented femoral total hip component and the femur by roentgen stereophotogrammetric analysis. Roentgen stereophotogrammetric analysis (RSA) was used to study rotation and subsidence of an uncemented polyethylene-coated femoral component for total hip arthroplasty in ten patients younger than 55 years of age. Three years postoperatively, the total subsidence averaged 2.44 mm and the internal rotation was 7.4 degrees. The rate of subsidence decreased between the observation periods, whereas the rate of rotation, after an initial significant decrease, became almost constant. One patient, who was a clinical failure and required revision arthroplasty, had a significantly higher rate of migration after six months. The pattern of subsidence in the absence of pain might be the normal reaction of bone to an uncemented prosthesis, but the continuing rotation suggests the potential for failure of the arthroplasty. The type of analysis made possible in RSA may allow early prediction of the success of arthroplasties and significantly speed the design cycle for arthroplasty components.
Desmoplastic fibroma of the maxillary sinus. Report of a case and review of the literature. A desmoplastic fibroma of the maxillary sinus is reported in a 15-year-old boy. Desmoplastic fibroma is a rare benign tumor in the maxillofacial region. The features of this case and of 49 previously described lesions are analyzed and discussed.
Polymorphous low-grade adenocarcinoma of minor salivary gland. A comparative histologic and immunohistochemical study. Sixteen polymorphous low-grade adenocarcinomas were reviewed and compared with 17 adenoid cystic carcinomas and with 21 other histologically similar minor salivary gland neoplasms. The polymorphous low-grade adenocarcinomas were for the most part distinctive in their microscopic appearance. Typically they exhibited infiltrative growth by small uniform cells in single-layered ducts. A syncytium of tumor cells was also characteristic, although solid and cribriform patterns were seen, making definitive diagnosis difficult with some tumors. Immunohistochemical staining for S-100 protein, glial fibrillary acidic protein, actin, vimentin, and keratins resulted in relatively distinctive antigenic profiles for the tumors studied. Of significance was strong S-100 protein and weak actin staining of polymorphous low-grade adenocarcinomas, moderate actin staining of adenoid cystic carcinomas, moderate glial fibrillary acidic protein staining of monomorphic adenomas and pleomorphic adenomas, and nonreactivity of monomorphic adenomas for vimentin. It is believed that the immunoprofiles could be useful in the microscopic diagnosis of salivary gland tumors. The identification of antigens found normally in myoepithelial and epithelial cells supports the concept that these tumors are derived from pluripotential reserve cells.
Left ventricular mass index and diastolic filling. Relation to blood pressure and demographic variables in a healthy biracial sample. The relationships of left ventricular (LV) structure and diastolic filling to ambulatory blood pressure, race, age, and gender were studied in 104 young, generally healthy, untreated subjects with normal or marginally elevated blood pressure. Average daytime systolic blood pressure (r = 0.41, P less than .001), diastolic blood pressure (r = 0.38, P less than .001), male gender (r = 0.49, P less than .001), and age (r = 0.32, P less than .001) were univariate correlates of LV mass index as measured by M-mode echocardiography. In a stepwise multiple regression model, male gender, age, and systolic blood pressure were independent predictors of LV mass index. LV filling rate normalized to mitral stroke volume, a Doppler-derived index of diastolic filling, was inversely related to age (r = -0.47, P less than .001), heart rate (r = -0.27, P less than .01), LV mass index (r = -0.32, P less than .001), and diastolic blood pressure (r = -0.20, P less than .05). Age, heart rate, and LV mass index were predictors of normalized peak filling in a stepwise regression model. Race was not significantly related to either LV mass index or diastolic filling. Our results confirm the importance of demographic variables as well as blood pressure in determining LV mass and filling characteristics in humans prior to the development of sustained essential hypertension. These variables contribute to ventricular mass and diastolic function in varying degrees. Gender is strongly correlated with LV mass, but not with filling indices.
Delays in the discharge of elderly patients. This paper reports a prospective study of the incidence and magnitude of delays in the discharge of 80 elderly (65+ years old) patients admitted to two general medical services in teaching hospitals in Edmonton, Alberta. The average length of stay was 16.6 days. Discharges were delayed in 14% (11/80) patients, accounting for 21% of the total days stay. Patients whose discharge was delayed tended to be older, to have delirium and/or dementia, to more often come from or require transfer to long term care (LTC) institutions, and/or to be dependent in essential activities of daily living. The 4-Score, an index for predicting non-medical days, was useful in identifying patients at risk for delays in discharge, and had a sensitivity of 0.82, and a specificity of 0.90. Interventions to reduce delays in discharge must address the frail nature of the patients, their lack of support and existing administrative relationships with LTC institutions. Acute care hospitals will likely need to undertake formal programs for the long term care of many of these patients.
Videoendoscopic evaluation of patients with dysphagia: an adjunct to the modified barium swallow. The modified barium swallow is currently the most comprehensive, widely available, and easily interpreted technique for the evaluation of patients with dysphagia by the head and neck surgeon. However, it requires the facilities, personnel, and use of a radiology suite, a trained speech pathologist, and exposure of the patient to radiation. It would therefore be helpful to have an adjunctive, physician based, nonradiographic method of examination that could provide information similar to and possibly even more complete than that supplied by the modified barium swallow. Such an adjunctive method could help otolaryngologist-head and neck surgeons confronted by a new patient with swallowing difficulties to orient themselves to the nature and severity of the problem while waiting for the modified barium swallow to be scheduled, performed, and reviewed. It could also be a helpful tool for management of patients with cancer of the head and neck, whose swallowing function may change rapidly in the early postoperative period. In such cases, intervals between modified barium swallow examinations (dictated by concern over radiation exposure) may be too far apart to allow up-to-the-minute decisions on case management. Finally, some patients who may be too ill to travel to the radiology suite might benefit from a bedside procedure that would yield information about swallowing function similar to that provided by the modified barium swallow. Videoendoscopic evaluation of dysphagia (VEED) is a protocol I developed and have used regularly since 1984. Experience with this method of dysphagia evaluation has shown that it answers the needs outlined above. Its usefulness also goes beyond that of the modified barium swallow by providing a more detailed understanding of the component anatomic and functional deficits that comprise a given patient's swallowing problem, information about upper aerodigestive tract sensory deficits, and a means for visual feedback training of pharyngeal and laryngeal musculature. The protocol is reviewed here. Case reports illustrating the clinical usefulness of VEED as an adjunct to the modified barium swallow are also presented, and the relative strengths and weaknesses of VEED and the modified barium swallow are compared.
Which pH threshold is best in esophageal pH monitoring? Two questions were examined, namely, 1) whether pH 4 is really the optimal threshold for the definition of acid gastroesophageal reflux, and 2) to what extent shifting of the upper limits of normal affects sensitivity and specificity of 24-h pH monitoring. To answer these questions, we studied 74 patients with proven reflux disease and 37 asymptomatic volunteers, using ambulatory 24-h esophageal pH monitoring. Gastroesophageal reflux was defined as episodes with esophageal pH of less than the threshold values 3.0, 3.5, 4.0, 4.5, or 5.0, respectively. For each of these pH thresholds, the percentage time with esophageal pH below the threshold was calculated separately for periods of upright and supine body position. Two-dimensional receiver-operating-characteristic (ROC) analysis was used to define upper limits of normal. A maximum of sensitivity, specificity, and rate of correct decisions (all 89%) was obtained using pH 4 for the definition of gastroesophageal reflux, although other pH thresholds were not much worse. On the basis of pH 4, the upper limits of normal could be shifted around the "optimal upper limit of normal" within a certain limit without considerable loss of accuracy of pH monitoring. This may explain the divergences between upper limits of normal obtained by different laboratories. In conclusion, 1) the threshold pH 4 should further be used for the definition of acid gastroesophageal reflux, and, 2) within certain limits, shifting of the upper limits of normal has little effect on the accuracy of pH monitoring in gastroesophageal reflux disease.
Deletion of the entire cytochrome P450 CYP2D6 gene as a cause of impaired drug metabolism in poor metabolizers of the debrisoquine/sparteine polymorphism. The debrisoquine/sparteine polymorphism is associated with a clinically important genetic deficiency of oxidative drug metabolism. From 5% to 10% of Caucasians designated as poor metabolizers (PMs) of the debrisoquine/sparteine polymorphism have a severely impaired capacity to metabolize more than 25 therapeutically used drugs. The impaired drug metabolism in PMs is due to the absence of cytochrome P450IID6 protein. The gene controlling the P450IID6 protein, CYP2D6, is located on the long arm of chromosome 22. A pseudogene CYP2D8P and a related gene CYP2D7 are located upstream from CYP2D6. This gene locus is highly polymorphic. After digestion of genomic DNA with XbaI endonuclease, restriction fragments of 11.5 kb and 44 kb represent mutant alleles of the cytochrome CYP2D6 gene locus associated with the PM phenotype. In order to elucidate the molecular mechanism of the mutant allele reflected by the XbaI 11.5-kb fragment, a genomic library was constructed from leukocyte DNA of one individual homozygous for this fragment and screened with the human IID6 cDNA. The CYP2D genes were isolated and characterized by restriction mapping and partial sequencing. We demonstrate that the mutant 11.5-kb allele results from a deletion involving the entire functional CYP2D6 gene. This result provides an explanation for the total absence of P450IID6 protein in the liver of these PMs.
Subclinical peripheral nerve involvement in AIDS: an electrophysiological and pathological study. Thirty patients with AIDS without symptoms or signs of peripheral neuropathy were compared electrophysiologically with 23 age and sex matched healthy controls. The patients had a mean reduction in the amplitude of common peroneal compound muscle action potentials of 37% (95% CI 11-70%) and of sural sensory action potentials of 34% (CI 18-49%). Mean conduction velocity of both motor and sensory nerves was reduced by between 1 and 7 m/s, with a prolongation of F waves corrected for height of 5% in the arms and 13% in the legs. The distal motor latencies were unchanged. These changes did not correlate with the duration of AIDS, degree of immunosuppression (CD4 count), Body Mass Index, albumin or vitamin B12 level. Four patients had subclinical mononeuropathies. Sural nerve taken at necropsy from five asymptomatic AIDS patients had evidence of axonal degeneration without inflammation or demyelination. There was a mean reduction in myelinated fibre density of 30.5% (CI 10-51%) compared with eight age matched sudden death controls (p = 0.01). This loss principally affected the larger fibres. The pathological and electrophysiological changes indicate axonal degeneration and are similar to those seen in other chronic disorders and in normal ageing. It is concluded that this axonal degeneration is not specific to HIV.
Primary progressive aphasia with focal neuronal achromasia. We describe the clinical, radiologic, neuropsychological, and neuropathologic features of a 69-year-old man with a 3-year history of progressive transcortical expressive aphasia. Neuropsychological testing showed progressive dysfunction of expressive language. Neuropathologic examination demonstrated focal cortical degeneration involving the left superior frontal gyrus, with swollen achromasic neurons and no evidence of Alzheimer's disease, Pick's disease, Creutzfeldt-Jakob disease, Lewybody disease, or other dementing disorders. This case adds to the known heterogeneity of the underlying pathology of patients with primary progressive aphasia.
Genomic structure of the human prion protein gene. Creutzfeld-Jacob disease and Gerstmann-Straussler syndrome are rare degenerative disorders of the nervous system which have been genetically linked to the prion protein (PrP) gene. The PrP gene encodes a host glycoprotein of unknown function and is located on the short arm of chromosome 20, a region with few known genes or anonymous markers. The complete structure of the PrP gene in man has not been determined despite considerable interest in its relationship to these unusual disorders. We have determined that the human PrP gene has the same simple genomic structure seen in the hamster gene and consists of two exons and a single intron. In contrast to the hamster PrP gene the human gene appears to have a single major transcriptional start site. The region immediately 5' of the transcriptional start site of the human PrP gene demonstrates the GC-rich features commonly seen in housekeeping genes. Curiously, the genomic clone we have isolated contains a 24-bp deletion that removes one of five octameric peptide repeats predicted to form a B-pleated sheet in this region of the PrP. We have also identified 5' of the PrP gene an RFLP which has a high degree of heterozygosity and which should serve as a useful marker for the pter-12 region of human chromosome 20.
Primary mucoid adenocarcinoma of the larynx. Mucous glands carcinomas of the larynx are rare, with most being represented by 'non-specific' adenocarcinoma and adenoid cystic carcinoma. Here we report a unique case of mucoid adenocarcinoma of the larynx occurring in a 46-year-old woman. Despite the presence of regional lymph node metastasis, she remained well four years after surgery.
Platelet activating factor-induced shock and intestinal necrosis in the rat: role of endogenous platelet-activating factor and effect of saline infusion. BACKGROUND AND METHODS: The mechanism of ischemic bowel necrosis induced by platelet-activating factor is unclear. Since intestinal hypoperfusion is observed after platelet-activating factor injection, we hypothesized that mesenteric vasoconstriction is the mechanism of bowel injury. The present study investigated the effects of saline infusion on platelet activating factor-induced bowel necrosis and its mechanism. Male Sprague-Dawley rats were divided into four groups: group A consisted of sham-operated rats; group B received platelet-activating factor (1.5 micrograms/kg iv); group C received platelet-activating factor and saline (0.097 mL/min iv); group D received platelet-activating factor and WEB 2086 (platelet-activating factor antagonist). RESULTS: Saline infusion largely reversed platelet activating factor-induced hypotension, hemoconcentration, and reduction of the superior mesenteric arterial blood flow. Saline infusion also ameliorated platelet activating factor-induced bowel injury, although a mild-to-moderate degree of necrosis still developed focally. In addition, saline prevented the platelet activating factor-induced increase in intestinal platelet-activating factor production. Saline also prevented the increase in intestine leukocyte number, as estimated by myeloperoxidase activity. CONCLUSIONS: Saline infusion is an effective treatment for platelet activating factor-induced shock and intestinal necrosis. However, focal bowel injury is still observed, suggesting that other factors besides hemodynamic changes contribute to the development of tissue injury. We also showed that, in vivo, platelet-activating factor stimulates its own synthesis via a positive feedback loop, which could be blocked by intravascular volume expansion with saline.