123rc/medical_text huggingface dataset:
Analysis of 24-hour esophageal pressure and pH data in unselected patients with noncardiac chest pain. Fourty-four unselected patients with noncardiac chest pain were studied using conventional manometry with additional edrophonium provocation and 24-hour ambulatory esophageal pH and pressure recording with a system developed by our group. New, fully automated techniques of statistical analysis of the complete set of esophageal pressure and pH signals were used to examine the temporal relation between pain, esophageal motility disturbances, and gastroesophageal reflux. The analysis used the 97.5th percentile of amplitude and duration of all esophageal contractions in each patient as well as a chi 2 test of the distribution of contraction types to determine whether a pain episode was related to abnormal motility or not. The edrophonium test results were positive in 2 patients. Only 25 patients (56.8%) had at least one pain episode (total, 111 episodes) during 24-hour recording. Thirty-three percent of the pain episodes were related to reflux and 23.4% to abnormal motility, and 43.2% were not related to an esophageal function disturbance. In the patient-oriented analysis in this study, it was required for a positive correlation that the symptom index (percentage of related pain episodes) was higher than 75%. It was found that the pain was related to reflux in 2 patients (4.6%), to reflux and motor abnormalities in 4 (9.2%), and to motor abnormalities in 2 patients (4.6%). In 36 patients (81.8%), no relation with an esophageal abnormality could be established, either because the patients had no pain during the 24-hour study, or because the pain seemed unrelated to reflux or abnormal motility.
The effect of chemotherapy on growth in the skeletally immature individual. One hundred twenty-two children with nonmetastatic osteogenic or Ewing's sarcoma were studied to assess the effect of multiagent adjuvant chemotherapy on skeletal growth and final stature. No deviations from the height distributions of a normal population were noted at diagnosis. There was a marked retardation of linear growth during the year of intensive chemotherapy. Only 15% of the patients grew at the expected rate during that year. The distribution of nutritional status scores was significantly different at the end of the first year than at baseline. The distribution of ultimate height scores was significantly different than the baseline distribution. The overall final distribution was also significantly different from the normal population expectation. Any absolute difference in height, however, is likely to be small. The subgroups that were observed to full adult stature showed mean heights of 162 cm for girls and 176 cm for boys.
Recurrent Bell's palsy in pregnancy. A case of recurrent Bell's palsy occurring in two successive pregnancies in a 37-year-old woman is presented. The causes of facial nerve paralysis of the lower motor neurone type are discussed. The rate of recurrence of Bell's palsy during pregnancy is unknown. Treatment with corticosteroids of Bell's palsy during pregnancy poses the threat of possible side effects on the fetus.
Prostate cancer: local staging with endorectal surface coil MR imaging. Endorectal surface coil magnetic resonance (MR) imaging was used to stage the local extent of prostate cancer in 22 patients. The endorectal coil images were acquired with a 10-12-cm field of view and a 4-mm section thickness. All pathologic specimens were reviewed by one pathologist. Endorectal surface coil MR imaging was 82% accurate in the differentiation of stage B from stage C cancer. One case was overestimated, and three cases were underestimated. The three underestimated cases consisted of two cases of microscopic capsular invasion and one case of minimal seminal vesicle invasion. In a comparison of retrospective, blinded readings of endorectal coil and body coil images, there was an average improvement in accuracy of 16% in staging prostate cancer with endorectal coil images.
Magnetic resonance in pediatric and adolescent neuroimaging. With improved availability and a practical understanding of the principles of utilization, MRI will continue to replace CT and US in pediatric neuroimaging, just as it has impacted upon the more invasive modalities. In general, US remains the procedure of choice for screening of fetal and infant CNS abnormalities, and CT continues as the principal screening modality beyond infancy and especially for acute, emergent presentations. MRI has now emerged as a primary option for screening as well as for more definitive assessment of many intracranial and most intraspinal conditions.
Repair of pelvic fracture posterior urethral defects using an elaborated perineal approach: experience with 74 cases. A total of 74 patients with posterior urethral distraction defects (1.5 to 7 cm. long) that followed pelvic fracture was managed by a 1-stage perineal repair. End-to-end anastomosis was performed in all cases but in 66 a variety of surgical maneuvers were necessary to accomplish a tension-free anastomosis. These techniques, which included distal urethral mobilization, corporeal body separation, inferior pubectomy and supracrural urethral rerouting, were resorted to in a sequential manner as needed. Excellent results were achieved in 96% of the cases. These surgical techniques are described and discussed.
Aspirin reduces the growth of medial and neointimal thickenings in balloon-injured rat carotid arteries. We analyzed the effect of Aspirin on the growth of experimentally induced vascular thickenings in rat carotid arteries. Vascular thickenings were induced by denudation of the endothelium in the left carotid artery with a balloon catheter. Administration of Aspirin-rich food (17.4 g/kg body wt/day) was started 1 week before and continued 2 weeks after injury. Nine rats were used. A control group of equal size received normal food. Sizes of the tunica media, the neointima, and the open vessel lumen were measured on cross sections of carotid segments with the aid of a videomorphometry system. The results show that in the Aspirin group, neointimal lesions are significantly smaller than in the control group (0.14 mm2 versus 0.23 mm2; p less than 0.5). Thickenings of the tunica media are also reduced (0.11 mm2 versus 0.12 mm2; p less than 0.5). It is suggested that Aspirin reduces both medial hypertrophy and neointimal outgrowth in injury-induced atherosclerosis.
Enteroliths causing intermittent obstruction in a patient with Crohn's disease. Calcified enteroliths as a cause of intermittent small bowel obstruction is an uncommon clinical entity. The pathophysiological mechanism involves stasis of intestinal contents and has been associated with Meckel's diverticulum, tuberculosis, and regional enteritis. This case describes prophylactic operative intervention in a symptomatic patient with enteroliths as a result of Crohn's disease.
Limitation of retinal injury by vitreoperfusion initiated after onset of ischemia. We tested whether vitreoperfusion, a new method of perfusing the vitreous cavity with solutions containing nutrients, can limit retinal injury if initiated after the onset of ischemia. Severe bilateral ocular ischemia was induced in cats with healed lensectomy-vitrectomy wounds; 30, 60, 90, or 120 minutes later, one eye from each of 18 cats underwent vitreoperfusion while the ischemia continued for 120 minutes. The other eye simultaneously underwent either continued untreated ischemia or reinstated circulation. The histopathologic abnormalities evident after 8 days depended on the duration of ischemia. Reinstated circulation yielded less retinal damage than continued ischemia. Nine additional cats underwent bilateral ischemia for at least 210 minutes. Vitreoperfusion was initiated in one eye after 30 minutes. In each cat, the vitreoperfused eye fared significantly better as observed histopathologically and electroretinographically. We believe that no other treatment has similarly limited retinal injury in vivo when initiated so long after total ocular ischemia has developed.
An overview of intimal hyperplasia. Many hypotheses have been postulated for the development of intimal hyperplasia in vein and prosthetic grafts. In these hypotheses, the central theme seems to be endothelial injury, but not always denuding injury. As we progress into the biologic era with more sophisticated research tools, the study of the endothelial cell may give us the answers to the problem of intimal hyperplasia. In addition, the leukocyte is still a relatively unknown entity and further modification of their function may hold promise.
Laparoscopic tubal sterilization. The potential for thermal bowel injury. One of the most severe complications of laparoscopic tubal sterilization is bowel burns, although they often go undetected at the time of laparoscopy. Controversy remains over whether these injuries are caused directly by operator error or indirectly from a hot oviduct's or instrument's inadvertently touching and burning the intestine. A study was performed to determine the potential for direct or indirect bowel burns using bipolar electrocoagulation in rabbits. The results indicate that neither a hot tube nor hot (recently used) forceps could cause injuries to the serosal surface of the intestine. That was true both of immediate injury and after one to five days of recovery. It was observed that the hot uterine tube caused significant bowel adhesions by five days after the procedure. Direct electrocoagulation of the bowel using 40 W for three seconds caused a minor, noticeable blanch on the bowel that was not detectable with gross or histologic means after one day of recovery. A direct bowel injury did result when 80 W was used for three seconds; the bowel became perforated after one day. These findings indicate that it is unlikely that one can produce a bowel burn indirectly from a hot uterine tube or instrument and that only a direct insult to the bowel appears to cause an injury. However, adhesions could be a complication of the procedure and should be considered.
Ultrasonographic diagnosis of a large placental intervillous thrombosis associated with elevated maternal serum alpha-fetoprotein level. A placental lesion associated with elevated maternal serum alpha-fetoprotein level and a positive Kleihauer-Betke test is reported. Serial ultrasonograms showed a progressive increase in the echogenicity of the lesion that corresponded to a large intervillous thrombosis after delivery. This case illustrates the importance of detailed ultrasonographic and pathologic placental investigations in pregnancies with unexplained elevated levels of alpha-fetoprotein.
Ichthyosis, exocrine pancreatic insufficiency, impaired neutrophil chemotaxis, growth retardation, and metaphyseal dysplasia (Shwachman syndrome). Report of a case with extensive skin lesions (clinical, histological, and ultrastructural findings). The Shwachman syndrome comprises exocrine pancreatic insufficiency, growth retardation, and bone marrow hypoplasia resulting in neutropenia. Clinical, morphological, and ultrastructural studies, as well as hair analysis, were performed in a patient with Shwachman's syndrome and severe ichthyosis. Clinical findings were lamellar ichthyosiform desquamation on the extremities. The hair was scanty and short on the scalp, in the eyelashes, and in the eyebrows. The nails were hyperkeratotic. Morphologic findings were slight, regular acanthosis and severe diffuse hyperkeratosis with variable parakeratosis. The granular layer was thickened. The papillary dermis showed very slight perivascular lymphocyte infiltration. The most prominent ultrastructural finding was the presence of solitary or multiple droplets of varying size in the cytoplasm of the keratinocytes. Hair analysis revealed no abnormalities; the cystine concentration in hair specimens was normal.
Impact of orifice geometry on the shape of jets: an in vitro Doppler color flow study. To investigate the influence of orifice geometry on the three-dimensional shape of jets, an in vitro Doppler color flow study was performed. Jets were formed by discharging blood through round orifices and through orifices with major/minor axis ratios of 2:1, 3:1 and 5:1. These were repeated with orifice areas of 0.1, 0.3 and 0.5 cm2. For turbulent and laminar jets formed by these orifices, Doppler color flow images were obtained from two orthogonal scanning planes aligned with the major and minor orifice axes. Jet width was measured at 1 cm intervals from 0 to 5 cm from the orifice and used to calculate jet eccentricity (ratio of major to minor axis widths) and the rate of divergence of the jet walls. Jets were observed to diverge more rapidly along walls aligned with the orifice minor axis rather than along the major axis. This differential spreading led to the development of circular symmetry at a short distance from the orifice. Jet divergence (theta) occurred more rapidly for turbulent jets and for jets formed by larger orifices: theta (zero) = 0.80 + 6.3.A + 7.0.T + 0.47.E-OR (r = 95, p less than 0.0001, n = 48), where A is orifice area (cm2); T is 0 for laminar jets, 1 for turbulent jets and E-OR combines orifice eccentricity and scanning orientation, ranging from -5 for 5:1 orifices imaged along the major axis, 0 for circular orifices to 5 for 5:1 orifices imaged along the minor axis. Within the jet, eccentricity decayed approximately exponentially with distance from the orifice, more rapidly for turbulent jets, more slowly for the larger and more eccentric orifices.
A long terminal repeat-containing retrotransposon is mobilized during hybrid dysgenesis in Drosophila virilis. A hybrid dysgenesis syndrome similar to those described in Drosophila melanogaster occurs in Drosophila virilis when a laboratory stock is crossed to a wild strain collected in the Batumi region of Georgia (U.S.S.R). Mutations in various loci obtained during these crosses are presumably induced by the insertion of DNA sequences. We have cloned an induced white mutation and characterized the insertion sequence responsible for the mutant phenotype. This sequence is a 10.6-kilobase (kb) transposable element we have named Ulysses. This element is flanked by unusually large 2.1-kb long terminal repeats. Ulysses also contains other landmarks characteristic of the retrotransposon family, such as a tRNA-binding site adjacent to the 5' long terminal repeat and open reading frames encoding putative products with homology to the reverse transcriptase, protease, and integrase domains typical of proteins encoded by vertebrate retroviruses. Some of the mutations obtained do not contain a copy of the Ulysses element at the mutant locus, suggesting that a different transposable element may be responsible for the mutation. Therefore, Ulysses may not be the primary cause of the entire dysgenic syndrome, and its mobilization may be the result of activation by an independent mobile element.
Age at onset of Alzheimer's disease. Relation to language dysfunction. A later age at onset of Alzheimer's disease (AD) was found to be related to diminished language performance in 86 patients with probable AD. A hierarchical linear model was constructed to assess effects of age at onset and disease duration on the performance of patients with AD on four language tasks (naming, reading, auditory comprehension, and writing to dictation) after controlling for disease severity. Results of univariate analysis, in which the dependent variable was the averaged language task performances, revealed a significant effect for age at onset of AD, but not for disease duration. To assess the possibility that the relationship between the age at onset of AD and language performance reflects effects of normal aging, the language tasks were given to 33 normal subjects of similar ages who scored perfectly on dementia severity measures. A convincing relationship was not found between test score and age.
Value and limitations of proximal jet dimensions for the quantitation of valvular regurgitation: an in vitro study using Doppler flow imaging. To evaluate usefulness and limitations of proximal jet dimensions for the quantitation of valvular regurgitation, fluid jets were created in a pulsatile flow model, and proximal jet width and cross-sectional area were measured by means of color Doppler flow imaging. When circular orifices with diameters from 1 to 6 mm were studied, jet width and cross-sectional jet area measured as close as possible to the orifice were directly related to the orifice diameter (r = 0.97; standard error of the estimate, 0.4 mm; y = 0.5 + 0.97x) and the orifice area (r = 0.97; standard error of the estimate, 5.7 mm2; y = 0.22 + 2.47x), respectively. No significant dependence on flow rate or pressure gradient was found for these measurements. Jet width was measured with color M-mode Doppler by use of the smallest sample volume size (1 mm) and was slightly greater than the orifice diameter (4.2 +/- 1.7 mm versus 3.8 +/- 1.7 mm). However, cross-sectional areas were approximately fourfold the orifice areas, on average (52.5 +/- 24.6 mm2 versus 12.3 +/- 9.7 mm2), with a range of twelvefold (smallest orifice) to threefold (largest orifice). When the sample volume size was reduced from 2.4 to 1.0 mm, color areas decreased by 25.6 +/- 6.0%. Slit-shaped orifices were studied with two different orientations of the slit-parallel and perpendicular to the ultrasound beam: Color M-mode measurements were again slightly greater than length and width of the slit, but cross-sectional areas were substantially larger than the orifice areas and increased between 44% and 115% when changing the orientation of the slit from perpendicular to parallel. This, again, reflected problems with lateral resolution. When cross-sectional areas were measured at increasing distances from the orifice, the cross-sectional jet area increased significantly within a few millimeters. This increase was greater with higher gradients and smaller orifice sizes. In case of a small orifice (2 mm) and a high gradient (130 to 160 mm Hg), increase in area was as great as 122% within a distance of only 5 mm. Thus, proximal jet width and cross-sectional area were directly related to the orifice size, which could be a valuable parameter for the evaluation of valvular regurgitation. Measurements of jet width by color M-mode seemed to be most accurate but are limited by the fact that in vivo valvular defects may be irregular rather than of circular shape.(ABSTRACT TRUNCATED AT 400 WORDS).
Biphasic modulation of acetaminophen bioactivation and hepatotoxicity by pretreatment with the interferon inducer polyinosinic-polycytidylic acid. Interferons and interferon induction can inhibit cytochromes P-450 and reduce the bioactivation and hepatotoxicity of acetaminophen. However, since P-450 inhibition often is followed by P-450 induction, which would enhance acetaminophen hepatotoxicity, the possibility of a biphasic modulation of acetaminophen hepatotoxicity by interferons was investigated. Outbred male CD-1 mice of various ages, and young inbred male C57BL/6 mice were given the interferon inducer, polyinosinic-polycytidylic acid (Poly I-C), 10 mg/kg intraperitoneally, followed 1 to 48 days later by a single dose of acetaminophen, 300 to 450 mg/kg intraperitoneally. Hepatotoxicity was assessed by the peak plasma concentration of alanine aminotransferase (ALT) occurring between 0 and 48 hr after acetaminophen treatment. Poly I-C inhibited the hepatotoxicity of acetaminophen given within 8 days, with maximal inhibition between 1 and 4 days. Conversely, a maximal 7-fold enhancement of ALT concentration was observed in CD-1 mice when 300 mg/kg of acetaminophen was given 32 days after Poly I-C (P less than 0.05). In the C57BL/6 strain, Poly I-C inhibited the hepatotoxicity of acetaminophen when given within 16 days, whereas a maximal 20-fold enhancement of ALT concentration was observed when 300 mg/kg of acetaminophen was given 24 days after Poly I-C (P less than 0.05). The mechanism of toxicologic enhancement was examined in male C57BL/6 mice using the same treatment regimen. Biochemical assessment of hepatotoxicity was confirmed by detailed histologic evaluation. Plasma concentrations of acetaminophen and metabolites were determined by high-performance liquid chromatography. Acetaminophen bioactivation was quantified by production of the glutathione-derived cysteine and mercapturic acid conjugates of acetaminophen. Poly I-C pretreatment produced a 5-fold increase in acetaminophen-induced ALT release (P less than 0.05), which correlated with histologic evidence of centrilobular necrosis. Poly I-C pretreatment produced respective 3-fold and 1.3-fold increases in the production of cysteine and mercapturic acid conjugates (P less than 0.05), which correlated with peak ALT concentrations (cysteine, r = 0.92, P less than 0.001; mercapturic acid, r = 0.75, P = 0.006). Thus, the hepatotoxicity of acetaminophen can be inhibited when given within days after interferon induction, and conversely enhanced when given after several weeks. The toxicologic enhancement appears to be due to increased P-450-catalyzed bioactivation of acetaminophen.
Prospective observations of 100 high-risk neonates by high-field (1.5 Tesla) magnetic resonance imaging of the central nervous system: I. Intraventricular and extracerebral lesions. The results of observations of the first 100 neonates at the University of Texas Health Science Center (Houston) who received magnetic resonance imaging of the central nervous system by means of a high-field image (1.5 T) are reported. All were assessed prospectively to be at risk neurodevelopmental delay. This first report specifically addresses the appearance of primarily hemorrhagic intracranial lesions, including intraventricular hemorrhage (n = 28), and extracerebral lesions, which include 3 cases of venous sinus thrombosis (n = 20). The signal intensities of hemorrhage underwent a characteristic evolution with time with only minor variations in the study group. Magnetic resonance imaging detected direct evidence of hemorrhage for up to 2 months, but hemosiderin was detected as a late indicator of hemorrhage for up to 9 months. Magnetic resonance imaging was equal in benefit to head ultrasonography and computed tomography for the diagnosis of intraventricular hemorrhage, but magnetic resonance imaging was also able to approximate the time of onset of hemorrhage. Magnetic resonance imaging was superior for the evaluation of extracerebral hemorrhage; ultrasonography failed to detect any of these lesions and computed tomography detected only 3 of 7. Short-term neurological abnormality was assessed, but the ability of magnetic resonance imaging to predict long-term neurodevelopmental delay is unknown and is the subject of an ongoing project.
The cellular biology of bone tumors. New knowledge in cell and molecular biology has begun to expand the understanding of the biology of osteosarcoma and Ewing's sarcoma. Studies on osteosarcomas have revealed abnormalities in the growth-inhibiting retinoblastoma gene, which may release cells from normal growth control. Abnormalities in growth factor production or response tend to inappropriately activate cell growth. Tumor cell DNA content and cytogenetics may affect the diagnosis and prognostic grouping of osteosarcomas. In Ewing's sarcomas, a characteristic translocation between Chromosomes 11 and 22 has been identified; this translocation is also found in malignant neuroepitheliomas. A variety of studies point to both neuroectodermal and mesenchymal origins for Ewing's sarcomas. Applications of new biologic knowledge and technology to clinical problems will lead to significant changes in the diagnosis, and perhaps in the treatment, of these tumors in the coming years. Collaborations between community and referral center physicians and scientists are critical for continued progress.