Melricflash/CW_MedAbstractsAlt huggingface dataset:
Fractures of the clivus: classification and clinical features. Fractures of the clival complex were diagnosed in a series of 17 patients admitted to the Maryland Institute for Emergency Medical Services System and the University of Maryland Medical System over a 30-month period. These fractures were divided pathologically into three types based upon their appearance on computed tomography: longitudinal, transverse, and oblique. The mechanisms of injury were similar in all groups, and the Glasgow Coma Scale scores at admission were comparable, regardless of fracture type, in survivors and nonsurvivors. Longitudinal fractures were associated with severe injury to the central nervous system and with brain stem infarction, and 4 of 6 (67%) of these patients died. Transverse fractures of the clival complex were found in 6 patients, 3 of whom (50%) died. All of these patients had fractures of the petrous ridge; 2 of the 3 survivors had multiple cranial nerve deficits, and one patient developed a carotid-cavernous fistula. Of the 5 patients with oblique clival fractures, 2 survived (40%), both of whom had multiple cranial nerve palsies; in addition, one of these patients developed a carotid-cavernous fistula. Using the present generation of computed tomographic scanners, fractures of the clival complex can be reliably diagnosed; they are probably more common than previously believed and can be separated into three groups based on the characteristics on computed tomographic scans and clinical findings. 

Category: nervous system diseases
Recurrent subacute torsion: prospective study of effects on testicular morphology and function. A prospective study was done on 43 consecutive patients with a diagnosis of recurrent subacute testicular torsion. All patients underwent full examination, hormonal assays and seminal fluid analysis before scrotal exploration, bilateral testicular biopsy and fixation. Seminal fluid analysis and hormonal assays were repeated 3 months postoperatively. Of the patients 36 were cured of recurrent pain, 35 of whom had a horizontally lying testis. No hormonal abnormalities were found preoperatively or postoperatively. Three patients had abnormal seminal fluid analysis. Testicular biopsies, including Johnsen scores, were abnormal in these 3 patients and normal in the other 33. It is concluded that patients with recurrent subacute torsion can be identified accurately and treated satisfactorily. There is little evidence that these patients suffer testicular damage as a result of this subacute torsion or that any pre-existing cellular abnormality exists to explain the oligospermia that frequently is seen in patients who have acute testicular torsion. 

Category: general pathological conditions
Retinal arterial macroaneurysms: risk factors and natural history. A case control study was conducted to identify the systemic and ocular risk factors for retinal arterial macroaneurysms. Forty-three patients with 52 photographically confirmed macroaneurysms were located. Forty-three age-matched, race-matched concurrent control patients were also identified. The patients with macroaneurysms had decreased visual acuity (p less than 0.0001) and a higher prevalence of hypertension (p = 0.037), female sex (p = 0.099), and retinal vein occlusions (p = 0.055) than controls. In patients with both a macroaneurysm and venous occlusion there was a 12.0 times higher prevalence of macroaneurysms in the area of retina drained by the occluded vein (p less than 0.05). Common findings associated with macroaneurysms included retinal haemorrhage (81% of patients), retinal exudate (70%), vitreous haemorrhage (30%), macular involvement (30%), and distal arteriolar narrowing (26%). Arteriolar occlusion occurred spontaneously (8%) or after laser photocoagulation (16%). 

Category: cardiovascular diseases
Treatment with desmopressin acetate in routine coronary artery bypass surgery to improve postoperative hemostasis. Desmopressin acetate (DDAVP) has been shown to decrease blood loss and transfusions in complex cardiac operations with long extracorporeal times. Its use in routine cardiac valve operations has been shown not to be beneficial, but its role in routine coronary artery bypass grafting operations has not been defined. We examined the effect of DDAVP in a prospective study of 60 patients undergoing uncomplicated primary coronary artery bypass grafting operations. Thirty consecutive patients received DDAVP (0.3 micrograms/kg) after cardiopulmonary bypass and were compared with 30 consecutive patients who did not receive DDAVP. No significant differences were seen in 12-hour mediastinal blood loss (465 +/- 207 ml with DDAVP versus 511 +/- 221 ml without DDAVP) or 12-24-hour mediastinal blood loss (236 +/- 127 ml with DDAVP versus 260 +/- 112 ml without DDAVP). Transfusion of blood products were similar for both groups. Platelet aggregometry at intraoperative and postoperative time points using ADP, collagen, and ristocetin was not significantly different from baseline values in either group. In a subgroup of patients with poor initial ristocetin-induced platelet aggregometry, a significant increase (p less than 0.05) in ristocetin-induced platelet aggregometry was seen postoperatively only in those patients who had received DDAVP. A decrease in blood loss and transfusions, however, was not demonstrable. In those patients who had been on aspirin or nonsteroidal anti-inflammatory drugs preoperatively, DDAVP did not improve mediastinal blood loss or transfusion needs. 

Category: general pathological conditions
Antinociceptive interaction between opioids and medetomidine: systemic additivity and spinal synergy. The antinociceptive interaction on the tail flick (TF) and hot plate (HP) tests between opioid analgesics and medetomidine after intravenous (iv) or intrathecal administration were examined by isobolographic analysis. Male Sprague-Dawley rats received fixed ratios of medetomidine to morphine, fentanyl, and meperidine of 1:10 and 1:30, 10:1, and 1:3, respectively, by iv administration or 10:1, 3:1 and 10:1, and 1:3 by intrathecal administration, respectively. Data were expressed as the percentage maximal possible effect (%MPE). The A50 (dose producing 50% MPE) for each drug or drug combination was determined from the dose-response curve. Isobolographic analysis revealed that the effect of medetomidine combined with fentanyl, morphine, or meperidine was additive after iv administration. The intrathecal administration of combinations of medetomidine with the opioids produced a synergistic antinociceptive effect in the TF but not HP test. These data confirmed that the interaction between medetomidine and opioids in producing antinociception may be additive or synergistic, depending on the route of administration, drug ratio administered, and level of processing of the nociceptive input (i.e., spinal vs. supraspinal). Moreover, these results were consistent with a spinal role for alpha-2 adrenoceptors in mediating antinociception. The authors suggest that the interaction between the opioid and alpha-2 adrenergic receptors occurs within the spinal cord. 

Category: nervous system diseases
Percutaneous fine-needle aspiration cytologic study of main pancreatic duct stenosis under pancreatographic guidance. When pancreatography shows a stenosis of the main pancreatic duct in patients with normal or inconclusive ultrasound and computed tomography, the exact nature of such stenosis is sometimes difficult to precise before surgical exploration. In such cases, the authors systematically performed a percutaneous fine-needle aspiration cytologic study of the stenosis under pancreatographic guidance. Fifteen patients were referred because of suspected pancreatic malignancy. The tumor markers, carcinoembryonic antigen (CEA) and CA 19-9 were normal in 11 patients and elevated in one patient, whereas only CA 19-9 was elevated in three others. In 14 cases, both the ultrasound and computed tomography did not show any obvious pancreatic mass. The pancreatography was done through endoscopic retrograde cholangiopancreatography (ERCP) (12 patients) or percutaneously in case of failure at ERCP3 and showed a main pancreatic duct stenosis that underwent aspiration by percutaneous fine needle precisely positioned using biplane fluoroscopy. The aspirated material was then smeared on glass slides, air-dried, and stained by Giemsa. In nine of the 15 patients, cytologic study revealed adenocarcinoma. This was confirmed by surgery in five and by progressive deterioration followed by death in four. In six patients, cytologic study gave a nonmalignant result. Chronic pancreatitis was found in five of them, confirmed at surgery in three and based on uneventful follow-up of at least 12 months in two others. In one case, a pancreatic adenocarcinoma not detected by cytologic study was found at surgery. Thus, the sensitivity and specificity of this diagnostic approach were 90% and 100%, respectively. No serious complication was noticed. The authors conclude that when ultrasound and computed tomography are inconclusive, percutaneous fine-needle aspiration cytologic study of main pancreatic duct stenosis under pancreatographic guidance is a safe, simple, and helpful procedure in the investigation of patients with suspected pancreatic malignancy. 

Category: neoplasms
Rapid eye movement sleep deprivation as a probe in elderly subjects. The effects of a 2-night rapid eye movement (REM) sleep deprivation (RSD) procedure on electroencephalographic sleep and mood were examined in 15 healthy elderly control subjects, 14 elderly patients with endogenous depression, and 15 patients with primary degenerative dementia. Compared with control subjects, both patient groups maintained a higher amount of REM sleep time and REM activity during RSD. Unexpectedly, depressed patients showed little rebound in visually scored or automated REM sleep measures following RSD, and they showed stability of REM activity temporal distribution from baseline to recovery conditions. This contrasted with the rebound in REM sleep activity seen in control subjects, and the more modest increase in demented patients. The RSD was fairly specific, with some impact on delta sleep during the procedure but not during recovery sleep. Mood ratings were unaffected by RSD. These findings demonstrated a greater plasticity of REM sleep regulation in the healthy elderly control subjects and suggested a higher REM "pressure" with a "ceiling effect" in depressed patients. Patients with dementia appeared to have an impaired capacity to respond to the challenge of RSD. 

Category: nervous system diseases
Cortical asymmetry of REM sleep EEG following unilateral pontine hemorrhage. A 24-year-old woman with a left pontine hematoma showed marked asymmetry in the EEG of REM sleep, suggesting that a unilateral pontine lesion is sufficient to disrupt normal REM sleep EEG in the ipsilateral hemisphere. Other REM sleep characteristics (rapid eye movements, muscle atonia) were unaffected by this lesion. 

Category: general pathological conditions
Presence of identical mitochondrial proteins in unstimulated constitutive steroid-producing R2C rat Leydig tumor and stimulated nonconstitutive steroid-producing MA-10 mouse Leydig tumor cells. The acute regulation of steroidogenesis in steroidogenic tissues requires de novo protein synthesis. It is believed that these newly synthesized proteins are instrumental in the delivery of the substrate, cholesterol, to the inner mitochondrial membrane where the cholesterol side-chain cleavage complex converts cholesterol to pregnenolone. A number of studies have attempted to characterize the protein(s) synthesized in response to hormone stimulation and, hence, function in the delivery of cholesterol to the cholesterol side-chain cleavage complex. While a number of potential protein candidates have been described, there is at present no unequivocal evidence which indicates that they are involved in steroidogenic regulation. We and others have described proteins that are induced in a variety of steroidogenic tissues in response to hormone stimulation and are localized in the mitochondria of these tissues. In an attempt to determine whether these induced proteins may be involved in steroidogenesis, we compared mitochondrial protein profiles in two separate Leydig tumor cell line. One cell line, the MA-10 mouse Leydig tumor cell line, has a very low basal steroid production, but synthesizes large amounts of progesterone in response to both tropic hormone and cAMP analog. The other cell line, the R2C rat Leydig tumor cell line, produces constitutively large amounts of progesterone, which cannot be increased further with hormone stimulation. Two-dimensional polyacrylamide gel electrophoresis profiles of newly synthesized mitochondrial proteins demonstrated that four 30-kDa proteins are induced in response to hormonal stimulation in MA-10 cells. Further, it was shown that proteins identical to these induced proteins are present constitutively in the mitochondria of R2C cells and cannot be further increased with hormone stimulation. These results strongly suggest that the 30-kDa mitochondrial proteins shown to be induced in several steroidogenic tissues are involved in the acute regulation of steroid production. 

Category: neoplasms
Stress and sudden death. The case of the long QT syndrome. The idiopathic long QT syndrome (LQTS) represents a unique clinical example of stress-related sudden cardiac death. LQTS is characterized by the association of several distinctive electrocardiographic features, among which prolongation of the QT interval is the best known, with life-threatening arrhythmias that usually occur under conditions of physical or psychological stress. Effective therapies exist and are represented by antiadrenergic interventions; beta-adrenergic-blocking agents are the treatment of choice. When they fail, left cardiac sympathetic denervation has also proven to be very effective. The latter result suggests a role for alpha-adrenergic mechanisms in the arrhythmias of LQTS. The stressors more frequently associated with syncopal events in LQTS patients include fear, exercise fraught with emotions, swimming, and awakening because of a loud noise. Experimentally, life threatening arrhythmias have been induced during a highly emotional situation in conscious cats with normal hearts in which right stellate ganglia have been ablated, resulting in QT interval prolongation. This selective denervation creates a sympathetic imbalance of the type proposed by one of the pathogenetic hypotheses for LQTS. 

Category: cardiovascular diseases
Intraocular pressure and the rate of visual field loss in chronic open-angle glaucoma. We measured the rate of change of visual field threshold values over time (mean follow-up, 44.9 +/- 17.4 months) by trend analysis in 40 eyes of 40 patients with chronic open-angle glaucoma. Twenty-eight eyes had stable visual fields, and two eyes had significant visual field improvement. Ten eyes had significant visual field deterioration and showed a correlation between indices of intraocular pressure (standard error of the mean, P = .02; standard deviation, P = .04; and range, P = .05) and the rate of visual field loss in the superonasal region of the visual field, such that the greater the variation of intraocular pressure the greater the rate of loss. The group losing visual fields had a higher mean visual field threshold value and significantly less optic disk pallor and cupping at the start of the study than the stable visual field group. Thus, a significant rate of visual field loss occurred at an earlier stage of the disease and showed a correlation with intraocular pressure in this stage. 

Category: general pathological conditions
Adenocarcinomas of the colon and rectum in persons under 40 years old. A population-based study. Data collected by nine population-based tumor registries participating in the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute were analyzed to characterize the epidemiology of noncarcinoid adenocarcinomas of the colon and rectum in young adults. Tumors diagnosed in persons under 40 years old between 1973 and 1984 (n = 1736) were compared with those in persons 40 years and older (n = 106,760). This first large U.S. population-based study of colorectal adenocarcinomas in the young shows a higher incidence in blacks than whites and later detection in black males. It also shows a higher proportion of tumors of mucinous and signet ring histological type than in older age groups. Among the younger group, the average annual age-adjusted incidence rate was 34% higher in black males than in white males (12.6 vs. 9.4 per million persons) and 46% higher in black females than in white females (13.0 vs 8.9 per million persons). The proportion of tumors that were right-sided varied by age: 0-29 years, 30%; 30-39 years, 26%; 40-49 years, 22%; 50-59 years, 21%; 60-69 years, 24%; 70-79 years, 30%; and 80+ years, 35%. Males under age 40 were less likely to present with localized disease (whites, 27%; blacks, 21%) than were those aged 40 and older (whites, 39%; blacks, 36%). The proportion of tumors classified as mucinous decreased with age, from 28% among those aged 0-19 years to 5% among those 40 years and older. A similar trend was observed for signet ring tumors. Although this latter type accounted for 10% of large-bowel tumors among subjects aged 0-19 years, this proportion decreased with age to 0.2% in those 40 years and older. 

Category: neoplasms
Multiple breakpoint method for measuring effect of antibiotics on endocarditis strains of streptococci. The activity of penicillin alone and combined with aminoglycoside on endocarditis strains of streptococci was examined. Good assay reproducibility was obtained by the use of logarithmic phase cultures standardised by opacity, careful inoculation of well-plates, removal of antibiotic by membrane transfer and incubating survival counts in hydrogen plus carbon dioxide. The use of 10-fold intervals for penicillin concentration simplified assay design without loss of efficiency. 

Category: cardiovascular diseases
Coronary artery fistula formation secondary to permanent pacemaker placement. We present the findings in two patients who apparently developed a coronary artery fistula as a complication of an endocardial pacing electrode. This complication may actually be occurring more frequently than recognized because the patient may be asymptomatic or minimally symptomatic and therefore not undergo a coronary angiogram. Awareness of this potentially serious complication is important and stresses the need for proper electrode placement without excess pressure on the tip. 

Category: cardiovascular diseases
Structure and distribution of an Alu-type deletion mutation in Sandhoff disease. Sandhoff disease is a recessively inherited lysosomal storage disease resulting from a deficiency of beta-hexosaminidase activity. The enzyme occurs in two major forms, beta-hexosaminidase A, composed of an alpha- and beta-subunit and beta-hexosaminidase B, composed of two beta-subunits. Both isozyme activities are deficient in Sandhoff disease, owing to mutations of the HEXB gene encoding the common beta-subunit. We have cloned and fully characterized a deletion at the HEXB gene from fibroblasts of a patient with the infantile form of Sandhoff disease. The deletion removes approximately 16 kb of DNA including the HEXB promoter, exons 1-5 and part of intron 5. It most likely arose from recombination between two Alu sequences, with the breakpoints occurring at the midpoint between the left and right arms in each case and regenerating an intact Alu element in the deletion sequence. The deletion allele accounts for 27% of the Sandhoff mutant alleles we analyzed. Two cell lines were shown to be homozygous for the deletion and both had the infantile form of the disease. Four additional patients were compound heterozygotes with other mutations, all of whom displayed a different clinical phenotype. Finally, the mutant allele was present in different ethnic backgrounds, suggesting that it may have been subject to genetic drift. 

Category: general pathological conditions
Enlarged cisterna magna and the Dandy-Walker malformation: factors associated with chromosome abnormalities. Thirty-three fetuses with an enlarged cisterna magna (10 mm or more) were evaluated to determine factors that might be associated with an underlying chromosome abnormality. Eighteen fetuses (55%) proved to have a chromosome abnormality, including trisomy 18 or trisomy 18 variant (12), trisomy 13 (three), Turner syndrome (one), or other rearrangements (two). Among various risk factors analyzed, the absence of ventricular dilatation correlated most strongly with a chromosome abnormality. Chromosome abnormalities were found in 17 of 22 fetuses (77%) lacking ventricular dilatation, compared with only one of 11 fetuses (9%) with ventricular dilatation (P less than .001). Other factors statistically associated (P less than .01) with an underlying chromosome abnormality included mild enlargement of the cisterna magna (10-14 mm), concurrent anomalies detected sonographically, and fetal growth retardation. However, stepwise logistic regression showed that only the absence of ventricular dilatation and the presence of concurrent anomalies were significant when multiple factors were evaluated. These observations support the utility of evaluating the cisterna magna as part of a routine anatomical survey. 

Category: general pathological conditions
MIC2 is a specific marker for Ewing's sarcoma and peripheral primitive neuroectodermal tumors. Evidence for a common histogenesis of Ewing's sarcoma and peripheral primitive neuroectodermal tumors from MIC2 expression and specific chromosome aberration. This study reports on the specific expression of the MIC2 gene, a pseudoautosomal gene located on the short arms of the X and Y chromosomes, on Ewing's sarcoma (ES) and peripheral primitive neuroectodermal tumor (pPNET) cells. The gene product, a cell membrane protein, is recognized by the newly established monoclonal antibody (MoAb) HBA-71 and the previously described MoAb 12E7 and RFB-1. Furthermore, the reaction pattern of the MIC2 antibodies, especially HBA-71, with normal tissues and a great number of benign and malignant tumors (70 different tumors, 199 tumor samples), as well as the correlation between the specific chromosomal aberrations, i.e., the t(11;22) and the del(22) and the expression of this antigen, are demonstrated. Both ES and pPNET cells express the MIC2 gene in very high amounts, which represents a highly selective and almost unique feature of these cells, making an assignment of these tumors in one entity even more likely. The MIC2 antibodies are of great value for clinical and research purposes. 

Category: neoplasms