Melricflash/CW_MedAbstractsAlt huggingface dataset:
Cerebrospinal fluid fistula and endoscopic sinus surgery. Seven cases of cerebrospinal fluid fistulae occurring as a result of endoscopic sinus surgery in a total of 800 ethmoidectomies are discussed, along with 1 case referred for consultation. One cerebrospinal fluid fistula was intrasphenoid, 4 were posterior ethmoid/base of skull, 2 were anterior ethmoid, and 1 was ethmoid cribriform. Six of 8 fistulae were closed endoscopically. The sphenoid sinus cerebrospinal fluid fistula was closed successfully with fibrin glue and Gelfoam. Five cerebrospinal fluid fistulae were closed successfully using fascia, muscle, and Gel-foam. Two cerebrospinal fluid fistulae were treated conservatively, and only 1 stopped. Anatomic and technical aspects related to the occurrence of cerebrospinal fluid fistulae are discussed. Management and treatment of cerebrospinal fluid fistulae occurring during and after endoscopic sinus surgery is emphasized. When identified intraoperatively or delayed, cerebrospinal fluid fistulae can be managed successfully by endoscopic technique. 

Category: general pathological conditions
Beta-adrenergic effects on carbohydrate metabolism in the unweighted rat soleus muscle. The effects of insulin on carbohydrate metabolism in atrophied rat soleus muscle are increased after unweighting by tail-cast suspension. This work has been extended by testing the effect of unweighting on the response of carbohydrate metabolism to isoproterenol, a beta-adrenergic agonist. Isoproterenol promoted glycogen degradation more in the unweighted than in the weight-bearing soleus but showed no differences in the extensor digitorum longus, which is unresponsive to hindlimb unweighting. In soleus muscles depleted of glycogen, to avoid varied inhibitory effects of glycogen on glycogen synthesis, isoproterenol inhibited this process more in the unweighted muscle. Isoproterenol did not have a greater inhibitory effect on net uptake of 2-deoxy-D[1,2-3H]glucose by the unweighted muscle. Measurements of intracellular 2-deoxy-[3H]glucose 6-phosphate and 3-O-methyl-D-[1-3H]glucose, which cannot be phosphorylated, showed that isoproterenol inhibited glucose phosphorylation but not transport. This effect could be explained by an increase of glucose 6-phosphate, an inhibitor of hexokinase. At 100 microU insulin/ml but not at a lower amount (10 microU/ml), isoproterenol inhibited hexose phosphorylation more in the control than in the unweighted muscle. This result may be explained by greater insulin antagonism in the unweighted muscle owing to increased insulin sensitivity. However, insulin antagonism of isoproterenol stimulation of glycogenolysis or inhibition of glycogenesis was not altered by unweighting. Therefore, for some aspects of carbohydrate metabolism, the unweighted muscle has an increased response to beta-adrenergic activation, just as this muscle shows increased responses to insulin. 

Category: general pathological conditions
Stunned myocardium and myocardial collagen damage: differential effects of single and repeated occlusions. It has been suggested that collagen loss and damage is responsible for the dysfunction seen in stunned myocardium. To test this hypothesis we compared collagen in canine hearts stunned by repeated occlusion with collagen in hearts stunned by a single occlusion. Regional contractile function was equally depressed in both groups: segment shortening at 1 hour after reperfusion averaged 37% +/- 9% versus 32% +/- 9% of preocclusion values in repeated and single occlusion models, respectively. Midmyocardial collagen content was not different in either single occlusion (10.5% +/- 0.4%) or repeated occlusion models (9.5% +/- 0.7%) when compared with nonischemic hearts (8.5 +/- 0.8%). Collagen damage, which was revealed with polarized light microscopy, was seen in 5 of 6 dogs after repeated occlusion but was not apparent after a single occlusion. Thus although both models of stunned myocardium produce similar dysfunction, there was no apparent collagen loss. Furthermore, collagen damage was only seen after repeated occlusion. Therefore it appears unlikely that collagen damage is a primary mechanism of stunned myocardium. 

Category: cardiovascular diseases
Surgical treatment of endomyocardial fibrosis: a new approach. Endomyocardial fibrosis has been treated surgically for many years. For complete removal of fibrosis from both ventricles by the classic technique, each atrioventricular (AV) valve was removed and replaced with a prosthesis. Relapse of endomyocardial fibrosis has not been observed after surgical correction. Reoperations have been carried out because of complications of valve prostheses. A new surgical technique for removal of ventricular fibrous tissue with preservation of the mitral and tricuspid valves was used in nine consecutive patients with endomyocardial fibrosis. Initial results show a reduction of pulmonary hypertension, mean right and left atrial pressures and end-diastolic pressures in both ventricles. Tricuspid annuloplasty was performed in seven patients and mitral annuloplasty in five. No valve prosthesis was used. There was no death and New York Heart Association functional class improved from class III or IV in the preoperative period to class I or II in the postoperative period. These data suggest that resection of endocardial fibrous tissue can be indicated early in the clinical course and performed with preservation of the AV valves. 

Category: cardiovascular diseases
Myocardial perfusion imaging with technetium-99m sestamibi SPECT in the evaluation of coronary artery disease. Technetium-99m (Tc-99m) sestamibi is a new myocardial perfusion imaging agent that offers significant advantages over thallium-201 (Tl-201) for myocardial perfusion imaging. The results of the current clinical trials using acquisition and processing parameters similar to those for Tl-201 and a separate (2-day) injection protocol suggest that Tc-99m sestamibi and Tl-201 single photon emission computed tomography (SPECT) provide similar information with respect to detection of myocardial perfusion defects, assessment of the pattern of defect reversibility, overall detection of coronary artery disease (CAD) and detection of disease in individual coronary arteries. Tc-99m sestamibi SPECT appears to be superior to Tc-99m sestamibi planar imaging because the former provides a higher defect contrast and is more accurate for detection of disease in individual coronary arteries. Research is currently under way addressing optimization of acquisition and processing of Tc-99m sestamibi studies and development of quantitative algorithms for detection and localization of CAD and sizing of transmural and nontransmural myocardial perfusion defects. It is expected that with the implementation of the final results of these new developments, further significant improvement in image quality will be attained, which in turn will further increase the confidence in image interpretation. Development of algorithms for analysis of end-diastolic myocardial images may allow better evaluation of small and nontransmural myocardial defects. Furthermore, gated studies may provide valuable information with respect to regional myocardial wall motion and wall thickening. With the implementation of algorithms for attenuation and scatter correction, the overall specificity of Tc-99m sestamibi SPECT should improve significantly because of a substantial decrease in the occurrence of attenuation-related image artifacts. 

Category: cardiovascular diseases
Angioscopic coronary macromorphology in patients with acute coronary disorders. To investigate the pathogenesis of acute coronary disorders and to clarify what type of plaque precedes these disorders, percutaneous transluminal coronary angioscopy, by means of a new angioscope, was carried out during catheterisation in 100 consecutive patients anatomically suitable for such investigations. The quality of the angioscopic image was good enough for analysis in 84 patients (14 with acute myocardial infarction [within 8 h of onset], 16 with recent myocardial infarction [3 days-2 months since onset], 24 with old myocardial infarctions, 10 with unstable angina, and 20 with stable angina). Thrombi were observed in most patients with acute coronary disorders (all 14 with acute myocardial infarction, 9 of 10 with unstable angina). Occlusive thrombi were more common in patients with acute myocardial infarction than in those with unstable angina (11 [79%] vs 1 [10%]; p less than 0.001), whereas mural (non-occlusive) thrombi were more common in the unstable angina than in the acute myocardial infarction group (8 [80%] vs 3 [21%]; p less than 0.001). Xanthomatous ulcerated plaques or ragged irregular surfaces were seen in patients with acute coronary disorders and in those with recent myocardial infarction. Xanthomatous plaques were more common in patients with acute coronary disorders (50%) than in those with stable angina (15%) or old myocardial infarction (8%). By contrast white and smooth plaques were seen in cases of stable angina and old myocardial infarction. Angioscopy could display the intracoronary lumen more precisely than could coronary arteriography. This angioscopic study suggested that, although a thrombus overlying a rupture in the lining of the plaque was common in both unstable angina and acute myocardial infarction, the character of the thrombus may differ between these disorders, and lipid-rich xanthomatous plaque may precede rupture. 

Category: general pathological conditions
Incisional parapubic hernias. A parapubic hernia, distinct from other lower abdominal wall hernias, is identified as a particular type of incisional hernia. This hernia results from the disruption of the musculotendinous elements of the abdominal wall as they insert into the pubis. This disruption is brought about by either the destruction of these musculotendinous tissues at their lower end or the resection of portions of the pubic bone as is sometimes done in suprapubic radical prostatectomies for easier access to the prostate. Seven cases have been identified and reported. Men and women were seen to make up a clinical picture that is suggestive of the diagnosis, namely, multiple previous operations through the lower abdominal wall, procedures of a gynecologic or urologic nature, a herniation that mimics an incisional or inguinal hernia, and a defect that cannot possibly be corrected without the use of a prosthesis. When the diagnosis is accurately established, the polypropylene mesh is inserted in the preperitoneal space and anchored laterally to the ligaments of Cooper and in between to the arcuate pubic ligament and the periosteum of the posterior aspect of the pubis. Excellent results have been obtained, and the success must be ascribed to the recognition of the parapubic hernia as a distinct entity. 

Category: digestive system diseases
Tissue-specific transformation by epidermal growth factor receptor: a single point mutation within the ATP-binding pocket of the erbB product increases its intrinsic kinase activity and activates its sarcomagenic potential. Avian c-erbB is activated to a leukemia oncogene following truncation of its amino-terminal, ligand-binding domain by retroviral insertion. The insertionally activated transcripts encode protein products that have constitutive tyrosine kinase activity and that can induce erythro-leukemia but not sarcomas. We have found that a single point mutation within the ATP-binding pocket of the tyrosine kinase domain in this truncated molecule can increase the ability of this oncogene to induce anchorage-independent growth of fibroblasts in vitro and fibrosarcoma formation in vivo. Associated with this increased transforming potential is a corresponding increase in the kinase activity of the mutant erbB protein product. The mutation, which converts a valine to isoleucine at position 157 of the insertionally activated c-erbB product, is at a residue that is highly conserved within the protein kinase family. To our knowledge, this is the first demonstration of a point mutation in the ATP-binding pocket that activates a tyrosine kinase. 

Category: general pathological conditions
Short-term changes in renal function, blood pressure, and electrolyte levels in patients receiving cyclosporine for dermatologic disorders. We compared the changes in renal function, blood pressure (BP), and concentrations of serum potassium, magnesium, and urate (uric acid) in two groups of patients not given transplants. Group 1, comprising 21 psoriatic patients, was treated with 14 mg/kg per day of oral cyclosporine for 4 weeks in a prospective, placebo-controlled study; group 2, comprising 28 patients with diverse cutaneous diseases, was given 6 mg/kg per day of oral cyclosporine for 1 to 3 months in a prospective, open-labeled study. Renal function (determined by serum urea nitrogen [SUN] and creatinine levels and urinalysis), BP, serum electrolyte levels (potassium and magnesium), and urate level were measured weekly for the first 4 weeks in both groups, and then, after 2 and 3 months of therapy, in group 2 only. During the first 4 weeks in group 1 patients, there were significant increases in values of SUN, creatinine, BP, potassium, and urate, and a significant decrease in the serum magnesium value. When data for the two groups were combined, the changes from pretherapy values in each of the above measures (except systolic BP) during the first 4 weeks correlated significantly with cyclosporine trough levels. In group 2, the changes that occurred in the first 4 weeks in the SUN value, SUN/creatinine ratio, and BP were magnified over the subsequent 8 weeks of treatment. In the combined group for the first 4 weeks of therapy, duration of therapy, independent of cyclosporine trough levels, correlated with changes in SUN, creatinine, and urate levels, but not with changes in the potassium or magnesium level or in BP. We conclude that the cyclosporine blood level was a better discriminant than cyclosporine dosage in the analysis of renal dysfunction and hypertension in these patients. 

Category: cardiovascular diseases
Complications of the pectoralis major myocutaneous flap in head and neck reconstruction. A retrospective review of the complications in 211 patients undergoing pectoralis major myocutaneous flap reconstruction is presented. The flap was used for mucosal lining of the oral cavity or oropharynx in 109 patients, for pharyngoesophageal reconstruction in 44, for skin coverage in 47, and for other locations in 14 patients. Flap-related complications developed in 63% of the patients. These included flap necrosis, suture line dehiscence, fistula formation, infection, and hematoma. Analysis of risk factors for the development of flap complications showed the following factors to be significant: age over 70; female gender; nomographic overweight; albumin less than 4 g/dL; use of the flap in reconstruction of the oral cavity after major glossectomy; and presence of other systemic diseases. The median length of hospitalization for those developing complications was 33 days compared with 16 days for those who did not develop any complications. Thirty-five (26%) of the 135 patients developing complications required reoperation and only 2 among these required a second flap. Similarly, only 13 of the 61 patients who developed fistulas required surgical closure. 

Category: neoplasms
Pyogenic hepatic abscess. Presented is a case of spontaneous pyogenic hepatic abscess in a previously healthy young man without associated risk factors. This disease entity has a low incidence, however, it is associated with significant morbidity and mortality if diagnosis and treatment are delayed. 

Category: general pathological conditions
Delayed chest wall pain due to sternal wire sutures. This report describes 18 patients with disabling chest wall pain due to one or more sternal wire sutures. The pain occurred from 2 to 84 months after a median sternotomy. The pain was described either as sharp and stabbing or as a deep-seated ache. The involved wires had an exaggerated fibrous tissue reaction surrounding the twisted portion. The adjacent noninvolved wires had minimal reaction. In the last 7 patients, serial sections of the fibrous tissue revealed entrapment of one or more sensory nerve fibers. In 6 of the 7 electrical potentials were measured and found to be elevated, indicating wire damage during twisting. Ferroxyl tests confirmed the collection of iron ions at this anodic point as a result of corrosion. Removal of the involved wires and the fibrous tissue surrounding this anodic point relieved the symptoms of pain and tenderness resulting from entrapped sensory nerves. 

Category: general pathological conditions
Unusual cause of 'piriformis muscle syndrome'. The piriformis muscle syndrome is a controversial "clinical" syndrome primarily characterized by signs and symptoms of sciatic nerve compression at the region of the piriformis muscle as it passes through the greater sciatic notch. The syndrome is often referred to; however, cases are rarely reported, and it is generally an uncommon diagnosis. Of those cases reported, the incidence is six times more frequent in females than in males, and is typically temporally related to minor pelvic or buttock trauma. We describe a case of a 40-year-old woman presenting with signs and symptoms suggestive of piriformis muscle syndrome following a gynecologic procedure performed in the dorsal lithotomy position. Electromyographic findings were consistent with this clinical entity. Operative exploration, however, revealed the source of neural compression to be a pseudoaneurysm of the inferior gluteal artery adjacent to the piriformis muscle. The diagnostic features of this clinical syndrome are discussed. 

Category: general pathological conditions
Trisomy 13: a new recurring chromosome abnormality in acute leukemia. A new recurring chromosome abnormality was identified in 8 of 621 consecutive successfully karyotyped adults with de novo acute leukemia. These eight patients had trisomy 13 as the sole cytogenetic abnormality. On central morphologic review, five cases were classified as subtypes of acute myeloid leukemia, one as acute mixed lymphoid and myeloid leukemia, one as acute lymphoid leukemia, and one as acute undifferentiated leukemia. Blasts of all eight cases expressed one or more myeloid differentiation antigens. Three also expressed T-lineage-associated antigens; however, none of these had rearrangement of the T-cell receptor beta, gamma, or delta genes. Four of six cases tested were TdT positive. All eight patients with trisomy 13 were treated with intensive induction chemotherapy; only three entered a short-lived complete remission. Survival of patients with trisomy 13 ranged from 0.5 to 14.7 months, and was significantly shorter than that of the remaining patients (median 9.5 v 16.2 months, P = .007). We conclude that trisomy 13 is a rare, recurring clonal chromosome abnormality in acute leukemia associated with a poor prognosis. Malignant transformation of an immature hematopoietic precursor cell is suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage, the high incidence of TdT positivity, and the morphologic heterogeneity in these leukemias. 

Category: neoplasms
Study of preneoplastic changes of liver cells by immunohistochemical and molecular hybridization techniques. The status of hepatitis B virus DNA was investigated by in situ hybridization in multifocal areas of a noncancerous hepatitis B virus-associated cirrhosis. This liver exhibited a marked degree of dysplasia and adenomatous hyperplasia. The results of these studies were correlated with the histopathology and immunohistochemical stains for hepatitis B core and surface antigens. There was clear evidence of a marked reduction to absence of hepatitis B viral DNA by in situ hybridization and absence of HBc and HBsAg in the foci of liver cell dysplasia and adenomatous hyperplasia. These results support the hypothesis that liver cell dysplasia and adenomatous hyperplasia are preneoplastic in nature. 

Category: general pathological conditions
Possible mechanisms of abnormal norepinephrine sensitivity and reactivity of resistance vessels and the development of hypertension in spontaneously hypertensive rats. A hypothesis. This study examined structural and functional changes of mesenteric resistance vessels in early, developing, and established stages of hypertension development in spontaneously hypertensive rats in an attempt to identify possible mechanisms of the development and maintenance of hypertension. Our results suggest that the development of hypertension in spontaneously hypertensive rats may be caused by genetic structural and functional abnormalities of resistance vessels. Both abnormalities may be caused by hyperreactivity to norepinephrine through an altered signal transduction process, including the regulation of protein kinase C in smooth muscle cells of resistance vessels in spontaneously hypertensive rats. 

Category: cardiovascular diseases
Very low birth weight children: behavior problems and school difficulty in a national sample We addressed three questions concerning the behavioral and academic status of low and very low birth weight infants through a secondary analysis of the 1981 National Health Interview Survey--Child Health Supplement: (1) in children born with very low birth weight, what is the risk of behavior problems and school difficulty compared with that in heavier low birth weight and normal birth weight children? (2) What are the correlates of school difficulty? (3) Are behavior problems associated with school difficulty when variables are controlled for these correlates? The analysis revealed that 34% of very low birth weight children could be characterized as having school difficulty, compared with 20% and 14% of the other groups, respectively, and that they were more likely to have higher scores on the hyperactive subscale of the Behavior Problems Index. Although a broad array of sociodemographic factors correlated with school difficulty, very low birth weight and hyperactivity scores contributed independently to the risk of academic problems. We conclude that very low birth weight infants are at risk of having school problems that are in part associated with hyperactive behavior. 

Category: nervous system diseases
Influence of chromosomal integration on glucocorticoid-regulated transcription of growth-stimulating papillomavirus genes E6 and E7 in cervical carcinoma cells. In most cervical carcinoma cells the E6 and E7 genes of specific human papillomaviruses are transcribed from viral sequences integrated into host cell chromosomes. Glucocorticoids activate the promoter elements of various human papillomaviruses in transient-expression assays. We have analyzed the effect of dexamethasone on the transcription rate of human papillomavirus 18 E6 and E7 genes integrated at different chromosomal sites in four cervical cancer cell lines. Dexamethasone led to an increase in the transcription rate of the integrated E6-E7 sequences in C4-1 and C4-2 cells but led to a decrease in SW 756 cells and did not affect the transcription rate in HeLa cells. However, when the viral promoter elements derived from HeLa or SW 756 cells, in which dexamethasone does not activate transcription of the integrated E6-E7 sequences, were tested in transient-expression assays within the same cell lines, dexamethasone consistently activated the viral promoter. It thus appears that dominant regulatory mechanisms presumably depending on the chromosomal integration site are able to override the response of the viral promoter to steroid hormones. The growth rate of all dexamethasone-treated cell lines correlated consistently with the expression of the papillomavirus E6 and E7 genes, supporting their role in the maintenance of the proliferative phenotype of cervical carcinoma cells. Since human papillomaviruses are integrated into the host cell genome at variable, presumably randomly selected chromosomal loci, regulatory mechanisms that influence viral gene expression, and hence cell growth, may differ among cancers of independent clonal origin. 

Category: neoplasms