123rc/medical_text huggingface dataset:
Data compression: effect on diagnostic accuracy in digital chest radiography. High-resolution digital images make up very large data sets that are relatively slow to transmit and expensive to store. Data compression techniques are being developed to address this problem, but significant image deterioration can occur at high compression ratios. In this study, the authors evaluated a form of adaptive block cosine transform coding, a new compression technique that allows considerable compression of digital radiographs with minimal degradation of image quality. To determine the effect of data compression on diagnostic accuracy, observer tests were performed with 60 digitized chest radiographs (2,048 x 2,048 matrix, 1,024 shades of gray) containing subtle examples of pneumothorax, interstitial infiltrate, nodules, and bone lesions. Radiographs with no compression, with 25:1 compression, and with 50:1 compression ratios were presented in randomized order to 12 radiologists. The results suggest that, with this compression scheme, compression ratios as high as 25:1 may be acceptable for primary diagnosis in chest radiology.
A nongastrin malignant ampullary tumor causing gastric acid and pepsin hypersecretion. A case report. We report a case of multiple duodenal ulcers with gastric hypersecretion due to a nongastrin secretagogue produced by a malignant tumor of the pancreas in a 78-year-old man. The case resembled a Zollinger-Ellison syndrome (ZES) with high acid output (basal acid output 27, sham meal-stimulated 37, maximum acid output 47 mEq/h), but with fasting gastrin 43 pg/ml, nonresponsive to secretin. As in ZES, pepsin output was comparatively low, and secretion was inhibitable by atropine (50% inhibited by 1 microM). The tumor removed at surgery contained less than 1 ng gastrin per gram, but was many times more potent than pentagastrin in stimulating acid from a lumen-perfused rat stomach. The tumor also contained cholecystokinin (CCK-8 and CCK-33), motilin, insulin, and somatostatin, which were also present in adjacent normal pancreas; in addition, the tumor contained pancreatic polypeptide and pancreatic cancer-associated antigen. This case represents a rare syndrome due to an as yet undefined peptide secreted by a (frequently malignant) pancreatic endocrine tumor and masquerading as ZES. This is the first report of studies of pepsin secretion and of the effect of atropine, suggesting that the physiologic effects of the secretagogue resemble that of gastrin.
Structural and ultrastructural study of the ovary in childhood leukemia after successful treatment. Ovarian biopsy specimens from ten girls (three postmenarcheal) who had undergone antiblastic treatment for acute lymphoblastic leukemia (ALL) and were in complete remission were examined by light microscope. The biopsy specimens from four of these patients (three postmenarcheal) were also observed by electron microscope. The structural and ultrastructural analysis showed a reduction in the number of follicles which were otherwise normal. No follicles were found in the thin sections from two of the three postmenarcheal girls, whereas normal follicles were observed in the third. The cortical stroma showed moderate to severe signs of fibrosis and changes of capillaries. All of these alterations were more evident in patients where ALL was diagnosed at an older age and this finding suggests that they are at a higher risk for low fertility or early menopause.
Focal nodular hyperplasia of the liver. Twenty-four patients underwent biopsy or resection of the liver for focal nodular hyperplasia (FNH) at Memorial Sloan-Kettering Cancer Center from 1978 to 1988. Twenty-two of the patients were women. The mean age was 35 years. A history of antecedent oral contraceptive or conjugated estrogen (Premarin) use was obtained in 18 of 21 women. There were two men, aged 26 and 37 years; neither gave a history of hormone use. Most of the tumors were solitary (22 of 24) and located in the left lobe of the liver (17 of 22). Fifteen of the patients had a prior or simultaneous malignant lesion and six had other benign tumors. Most of the tumors were resected with a wedge or subsegment of liver (13 of 24). Four patients underwent segmentectomy and five required lobectomy for removal of the tumors. Two patients had an intraoperative biopsy only. The patients in whom the tumor was diagnosed preoperatively underwent computed tomography and arteriography routinely. Scintigraphy of the liver with sulfur colloid was obtained in only three patients, despite its distinct potential for nonoperative diagnosis of FNH.
Clinical management issues in males with sex chromosomal mosaicism and discordant phenotype/sex chromosomal patterns. The recent availability of Y DNA probes has made it possible to identify two forms of 46,XX male syndrome: Y DNA positive and Y DNA negative. The Y DNA positive male results from a X;Y translocation with a low recurrence risk; the Y DNA negative males are due to a mutation with a high recurrence risk. 46,XX males and mosaic forms are phenotypically indistinguishable. A review of the case histories for 11 individuals indicates that affected males have highly variable genital and nongenital phenotypes. Physical findings may be clearly apparent or nonexistent. With the exception of external genitalia, the basis for this variability is unknown. It may be related to differences in Y chromatin expression as the result of variable inactivation of the X chromosomes, or to the existence of minor deletions or point mutations secondary to an exchange of genetic material. Common and uncommon clinical problems in these individuals require evaluation and follow-up care that is provided through a cooperative, interdisciplinary approach.
The lack of full correlation between the Injury Severity Score and the resource needs of injured patients STUDY OBJECTIVE: To determine whether the Injury Severity Score (ISS) correlates with the resource requirements of severely injured patients by studying the association of the ISS with three major interventions (fluid resuscitation, invasive central nervous system monitoring, and acute operative repair) trauma centers routinely provide severely injured patients. DESIGN: Retrospective clinical review. SETTING: Level I trauma center. TYPE OF PARTICIPANTS: Eight hundred fourteen adult injured patients. MEASUREMENTS AND MAIN RESULTS: When an ISS of more than 9 was used as the definition of major trauma, the ISS undercorrelated 11% of the time with the need for any one procedure. When an ISS of more than 14 was used as the definition, it undercorrelated 20% of the time. CONCLUSION: The ISS may not be completely correlated with the resource requirements of injured patients and should not be used as the sole means by which to define major injury.
Comprehensive management of acute necrotizing pancreatitis and pancreatic abscess. Achieving reduced mortality rates in patients with necrotizing pancreatitis and pancreatic abscess is possible by employing a comprehensive management plan. Components of the plan include (1) rapid evaluation and assessment of the degree of physiologic and anatomic derangement, the latter by the prompt use of vascular enhanced computed tomographic scan; (2) adequate fluid resuscitation determined by early institution of advanced hemodynamic monitoring; (3) attempts to identify and document septic foci via computed tomography-guided percutaneous aspiration; and (4) aggressive surgical debridement. Close adherence to these policies allowed us to keep mortality in this seriously ill group of patients to 14%. Most deaths occurred in patients who were referred to this service late in the course of their disease. The Acute Physiology and Chronic Health Enquiry (APACHE) II severity of illness index applied at the time of admission proved an accurate predictor of mortality. A score of 25 or greater was highly predictive of death, and a lesser score, of survival.
Mechanism of early ischemic contractile failure. Inexcitability, metabolite accumulation, or vascular collapse? The basis of early ischemic contractile failure was investigated in perfused ferret hearts at 27 degrees C. Isovolumic left ventricular developed pressure fell by more than 50% within 30 seconds of the onset of total global ischemia and reached zero by 5 minutes. Monophasic action potential recordings revealed no decrease in excitability during this period. Phosphorus nuclear magnetic resonance spectra obtained at 30-second resolution showed no significant changes in inorganic phosphate or phosphocreatine during the first 30 seconds of ischemia. Intracellular pH (pHi) and ATP changed even more slowly; therefore, none of these metabolites could account for the rapid fall in force. To gauge the contribution of intravascular pressure, we compared ordinary aortic flow occlusion with tissue-level ischemia induced by massive coronary microembolization at the level of the precapillary arterioles. Functional depression developed significantly more slowly in the microembolized hearts, despite accumulation of inorganic phosphate and protons comparable with that in ordinary ischemia. After microembolization, the time course of functional depression reflected much more closely the concomitant inorganic phosphate and pHi changes. Thus, our results provide novel evidence supporting the importance of vascular collapse in the mechanism of early ischemic contractile failure.
Effects of hypothyroidism on bronchial reactivity in non-asthmatic subjects. The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms). The dose producing a 35% decrease in sGaw (PD35) was determined from the cumulative log dose-response curve by linear regression analysis. Mean baseline sGaw values were similar when the patients were hypothyroid and when they were hyperthyroid (1.35 (0.36) and 1.41 (0.56) s-1 kPa-1). The interstudy coefficients of variation of baseline sGaw were higher in the thyroid patients than in a euthyroid control group (14% versus 8%). Geometric mean PD35 was lower when the patients were hypothyroid (97 micrograms) than when they were mildly hyperthyroid (192 micrograms). It is concluded that acute hypothyroidism increases non-specific bronchial reactivity in nonasthmatic subjects.
Marker profile of different phases in the transition of normal human ovarian epithelium to ovarian carcinomas. To investigate whether early changes in the transformation of normal ovarian epithelial cells into tumor cells can be detected with monoclonal antibodies, a comparative immunohistochemical study was performed on normal human ovarian mesothelial cells, cystomas, cystadenomas, ovarian carcinomas, as well as granulosa cell tumor. Using monoclonal antibodies against different keratin subtypes, it was shown that mesothelial cells, ovarian cysts, cystadenomas, and carcinomas all reacted positively with broad-spectrum anti-keratin monoclonal antibodies (MAbs), as well as with MAbs to keratins 7, 8, 18, and 19. Keratins 4 and 13 were not found in mesothelial cells, but positive groups of cells were identified in several cystomas, adenomas, and carcinomas. While mesothelial cells did not react with the pan-epithelial marker BW495/36, invaginating metaplastic mesothelial cells, inclusion cysts, cystomas, adenomas, and carcinomas showed an increasing reactivity with BW495/36, with an increasing degree of malignancy. The reactivity of MAbs against ovarian carcinoma-associated antigens (OV-TL 3, OC 125, MOv 18, and OV-TL 10) was limited to weak staining reaction in some mesothelial cells but were found to be positive on more than 50% of the ovarian cystadenomas and more than 90% of the ovarian carcinomas. Thecal and granulosa cells of primordial, primary, and secondary follicles all reacted positively with antibodies to the broad-spectrum keratins OV-TL 12/5 and RCK 102, and to keratins 8 and 18, but not with keratins 4, 7, 13, and 19. These keratins decreased or disappeared in granulosa cells of mature follicles (Graafian follicles), whereas granulosa cell tumors did not react with anti-keratin antibodies. The reactivity of BW 495/36 was negative or limited to traces in some granulosa cells. Ovarian carcinoma-associated antigens were not expressed in granulosa cells or granulosa cell tumors. The data indicate that mesothelial cells undergoing metaplastic changes finally resulting in ovarian cystadenomas (and carcinomas) initiate the synthesis of a 200-kd glycoprotein recognized by MAb (BW 495/36), the production of ovarian carcinoma associated antigens, in addition to focal production of keratin 4 and/or 13, as seen in several samples. The granulosa cell tumors decrease or switch off their keratin production and remain negative for the 200-kd glycoprotein and the ovarian carcinoma-associated antigens.
Serum acute phase proteins after orthotopic liver transplantation. Acute phase proteins were measured in six patients before liver transplantation and for 72 h after orthotopic liver transplantation. The ability of the donor liver to mount an acute phase response was demonstrated, although the response was less than that seen in other groups of patients in whom this has been studied. Because of the reduced response to stress, the value of these measurements as indicators of liver function in this group of patients is limited.
Subarachnoid hemorrhage caused by a fungal aneurysm of the vertebral artery as a complication of intracranial aneurysm clipping. Case report. Intracranial aneurysms are an uncommon manifestation of fungal infection. A case is described in which the formation of an aneurysm followed an intracranial intraoperative Aspergillus infection attributable to a long period of preoperative antibiotic medication and immunosuppressive therapy with steroids.
Evidence of hibernating myocardium by a new transesophageal echocardiographic technique. Reversal of resting wall motion abnormalities after successful coronary angioplasty were documented in a patient with the use of a novel approach to stress testing. Transesophageal stress echocardiography utilizes transesophageal atrial pacing to provoke myocardial ischemia while the left ventricular contractility is being monitored by means of transesophageal echocardiography. The potential use of this technique is illustrated in this report.
Calculated risk of chromosomal abnormalities in twin gestations. Genetic counseling concerning the risks of chromosomal abnormalities in twin gestations can be difficult; the risk of amniocentesis is weighed against that of chromosomal abnormalities in either one or both of the twins. Because most twins are dizygotic (each with a risk a priori of aneuploidy), the chance that one of the fetuses is affected is greater than would be expected for a singleton. Only three possibilities would result in either one or both twin's being affected: 1) dizygotic twins with one fetus affected, 2) dizygotic twins with both fetuses affected, and 3) monozygotic twins with both fetuses affected. Using existing tables of estimated risks of chromosomal abnormalities in singleton gestations and mathematically derived formulas, we created tables defining the age-related risks of chromosomal abnormalities in twin gestations. According to these tables, a patient at 33 years of age with a twin gestation has a risk of Down syndrome in at least one of her twins equivalent to that of a 35-year-old with a singleton. Prenatal genetic testing should be considered for women with twins at a younger age than the traditional 35.
DNA sequence analysis of three inhibitor-positive hemophilia B patients without gross gene deletion: identification of four novel mutations in factor IX gene. Three hemophilia B patients with anti-factor IX antibodies who had no detectable gross deletion of the factor IX gene by Southern blotting analysis were investigated at the molecular level. All eight exons, accompanied by their splicing junction sites and presumptive promoter regions of the factor IX gene in these patients (total 5.5 kb in length) were amplified with the use of the polymerase chain reaction, followed by complete nucleotide sequence analysis. Three different types of novel single base substitutions and a 2 base-pair nucleotide deletion were identified. Patient HB-5 had two point mutations in his factor IX gene. One was located at the promoter region at nucleotide -793 and the other (C-to-T transition) was found in exon VI of the gene changing Gln-191 to a stop codon. Patient HB-6 had a point mutation (G-to-A) in the splice acceptor site, which interrupted the normal splicing of the last intron G. A small two-nucleotide deletion in exon III was detected in patient HB-7 and yielded frameshifted amino acids and terminated by a stop codon. These resuslts suggest that not only the gross gene deletion of factor IX gene but also the point mutations or small nucleotide deletion that may cause the interruption of coding informations for mature protein synthesis is predisposed to development of anti-factor IX inhibitors in patients with hemophilia B.
Internal capsule plaque and tonic spasms in multiple sclerosis. A patient developed hemilateral tonic spasms associated with a relapse of multiple sclerosis. An area of demyelination in the right internal capsule was observed on a magnetic resonance imaging scan. This lesion was not detectable on a second magnetic resonance imaging scan 10 months after the spasms had ceased. Paroxysmal symptoms in multiple sclerosis may represent transient phenomena related to inflammation in acute plaques.
Timing of corticosteroid treatment. Effect of lung lymph dynamics in air injury in awake sheep. In paired experiments, we studied the effects of high-dose methylprednisolone on the acute pulmonary injury caused by 4 h of venous air embolization in 19 chronically instrumented, unanesthetized sheep with lung lymph fistulas. We compared the effect of methylprednisolone (30 mg/kg intravenous bolus) given before embolization, early (1 H) in the course of embolization, late (3 h) in the course of embolization, or after embolization (at the beginning of the recovery period). We measured pulmonary hemodynamics and lymph dynamics. In six sheep we also fixed lung tissue for semiquantitative histology, and in some we measured leukocyte concentrations in blood and in pulmonary lymph. Methylprednisolone did not significantly affect pulmonary hemodynamics but it largely prevented lung injury when it was given before embolization. It also lessened the degree of lung injury when it was given during embolization, although this effect became less marked as treatment was delayed. Methylprednisolone had no effect on lung injury when given after embolization was completed (4 h). We found fewer leukocytes attached to air emboli and fewer endothelial cell gaps in the lungs of sheep given methylprednisolone as prophylaxis. Leukocyte counts were lower in lung lymph and higher in the circulating blood of methylprednisolone-treated sheep. We conclude that methylprednisolone has a preventive effect on air embolism lung injury, such that its effect is greater when given earlier during the development of injury.
Hospitalization and the cognitive deficits of schizophrenia. The influences of age and education. The study investigated the relationship between length of hospitalization and increasing cognitive deficit in schizophrenics. Using Halstead-Reitan Battery data obtained from 245 schizophrenic patients, multiple regression analyses were performed using age, education, and length of hospitalization as independent variables and various summary test indices as dependent variables. These analyses showed that there was not a statistically significant change in percentage of explained variance when length of hospitalization was entered into the multiple regression equations. On the basis of these analyses, it was concluded that the association between increasing deficit and length of hospitalization experienced by schizophrenic patients is no greater than what would be anticipated on the basis of aging.
Prostacyclin but not phentolamine increases oxygen consumption and skin microvascular blood flow in patients with sepsis and respiratory failure. Inadequate tissue oxygenation may occur in critically ill patients with sepsis despite an apparently adequate O2 transport (QO2), and this may contribute to the development of an O2 debt and also to multiple organ failure. It has been shown that increasing QO2 by infusing a vasodilator may reveal this O2 debt in septic patients. To investigate whether the site of action of vasodilators may be of importance in unmasking such an O2 debt, we administered prostacyclin, a prostaglandin with a preferential effect on the microcirculation, and phentolamine, an arteriolar vasodilator, in 11 patients studied during the first 48 hours after the onset of sepsis, and compared their effect on whole body oxygen consumption (VO2) and skin microvascular blood flow. The results demonstrated that increasing QO2 by prostacyclin but not by phentolamine significantly increases VO2 in critically ill patients with sepsis. The site of action of vasodilators may therefore play an important role in their ability to unmask an O2 debt.
Autograft versus allograft for benign lesions in children. Benign bone lesions in children are often so large in size that there is not an adequate amount of bone available for an autograft to fill the resultant cavity after surgical curettage. This study compared autografts and allografts with respect to the time required and the success of graft incorporation. Fifty-four patients with 61 lesions were studied. Lesions were classified as small volume (less than 60 cc) or large volume (more than 60 cc) and were separated into four groups: small-volume autograft, large-volume autograft, small-volume allograft, and large-volume allograft. Allografts appeared comparable to autografts when small-volume lesions were treated. The healing time was slightly longer for allografts with an average period of 21 months versus 27 months for autografts. Autografts were superior to allografts in rate and completeness of healing for solitary large lesions. This increased efficacy presumes a somewhat older child in which an adequate amount of bone is available for an autograft. A young child with multicentric or polyostotic lesions can still achieve successful incorporation with allografts. In this study, 38% healed completely and 29% healed partially. Allografts have a distinct place in the treatment of benign bone lesions in children.
A paradigm for restenosis based on cell biology: clues for the development of new preventive therapies. Angioplasty causes substantial injury to the coronary artery intima and media that is unrecognizable by angiography. On the basis of a substantial body of research in oncology and wound healing, it is hypothesized that restenosis is a manifestation of the general wound healing response expressed specifically in vascular tissue. The temporal response to injury occurs in three characteristic phases: inflammation, granulation and extracellular matrix remodeling. The specific expression of these phases in the coronary artery leads to intimal hyperplasia at 1 to 4 months. The major milestones in the temporal sequence of restenosis are platelet aggregation, inflammatory cell infiltration, release of growth factors, medial smooth muscle cell modulation and proliferation, proteoglycan deposition and extracellular matrix remodeling. Each step has potential inhibitors that could be used for preventive therapy. Resolution of restenosis, however, probably requires both creation of the largest possible residual lumen and substantial inhibition of intimal hyperplasia.