Melricflash/CW_MedAbstractsAlt huggingface dataset:
In vitro and in vivo testing of a new valved intravascular catheter design. Long-term intravascular catheterization carries a finite risk of catheter occlusion. A catheter tip valve design is presented (Buchwald-Wigness, Strato Medical Corporation, Beverly, MA) which incorporates features designed to decrease the risk of thromboembolism and reduce the need for maintenance procedures. Aspiration and infusion are controlled by separate valves, making it possible to engineer optimized inlet and outlet parameters. The outlet valve is an elastic sleeve expanded around the sidewall outlet ports which opens under injection pressure. The inlet valve is a tubular elastic element compressed against the inlet port from within the lumen, opening under aspiration pressure. A series of valves were prototyped with outlet pressures ranging from 2 to 100" H2O, and inlet pressures ranging from -40-70" H2O, and flowrates at 36" H2O of greater than 1,400 ml/hr. Dog implants of two prototypes with outlet valve pressures of 10" H2O, and inlet pressures of -40" H2O, demonstrated that dormant periods of up to 7.5 weeks could be achieved without detectable blood cell entry into the lumen. No significant hemolysis was observed in blood samples aspirated with a 6 cc syringe (8% scored "slightly hemolyzed" vs. 44% with the nonvalved controls) indicating that a hemodialysis application is likely. 

Category: cardiovascular diseases
Late results of 200 repeat coronary artery bypass operations. To determine the clinical outcome and the long-term results of a second coronary artery bypass operation, we studied preoperative clinical status and catheterization data in 200 consecutive patients over a 9-year period (1979 to 1987) (mean follow up time 34 months, maximum 120). The study group included 169 men and 31 women (mean age 58.4 years [7% greater than 70 years]). Sixty-four percent of patients had severe angina (New York Heart Association class IV), 70% had 3-vessel coronary artery disease and 21% had poor left ventricular function. Reoperation was performed after a mean interval of 58 months after the first procedure. A mean of 3.3 distal anastomoses was placed. The operative mortality rate (30 days) was 7.5%, with additional cardiac morbidity (myocardial infarction, heart failure) in 11.5% of patients. Multivariate analysis showed an increased risk in women (risk ratio 3.6) and in patients with poor left ventricular function (risk ratio 3.1). The cumulative 5-year survival rate was estimated at 84%, with a rate of 77% for patients with poor left ventricular function (difference not significant). The probability of remaining free of a cardiac-related event (myocardial infarction, angioplasty, third operation, cardiac death) was 64% for 5 years. At the end of follow-up, 79% of the surviving patients were in New York Heart Association class I or II and nearly 50% of patients in the fifth year after the reoperation had good functional status. It is concluded that a reoperation is effective but carries an increased, immediate, operative risk. 

Category: cardiovascular diseases
Functional results of facial nerve suture after removal of acoustic neurinoma: analysis of 25 cases. The facial nerve is sometimes severed during the removal of acoustic neurinomas, either intentionally to ensure complete removal, or unintentionally because of difficulties in identification. In such cases we have, if possible, sutured the nerve stumps microsurgically, either end to end or by use of an intervening nerve graft. We analyzed the outcome of 25 instances of facial nerve suturing in a series of 219 patients operated on for acoustic neurinoma from 1979 to 1987. The first signs of recovery appeared at an average of 12 months, and there was continued improvement for several years. Recovery was graded from 1 to 6. The anastomosis was successful in 24 of the 25 sutured nerves, in that at least some facial movement and tone were restored (Grade 5 or higher). In 11 of the 25 cases, facial appearance at rest and with movement was moderately good (Grade 2 or 3). A Grade 1 result, with no perceivable facial dysfunction, was never achieved. Typically, oral muscles showed the most improvement and frontal muscles the least. Facial appearance was better at rest than with movement, which was always complicated by some degree of synkinesis. Closure of the eye was so good in 13 of the 25 cases that neither tarsorrhaphy nor an eyelid spring was necessary. When the facial nerve is severed, intraoperative suture is recommended, because it provides a chance for moderately good restoration of facial appearance. 

Category: general pathological conditions
MyoD induces growth arrest independent of differentiation in normal and transformed cells. MyoD is a gene involved in the control of muscle differentiation. We show that MyoD causes growth arrest when expressed in cell lines derived from tumors or transformed by different oncogenes. MyoD-induced growth inhibition was demonstrated by reduction in the efficiency of colony formation and at the single-cell level. We further show that MyoD growth inhibition can occur in cells that are not induced to activate muscle differentiation markers. The inhibitory activity of MyoD was mapped to the same 68-amino acid segment necessary and sufficient for induction of muscle differentiation, the basic-helix-loop-helix motif. Mutants with alterations in the basic region of MyoD that fail to bind or do not activate a muscle-specific enhancer inhibited growth; mutants with deletions in the helix-loop-helix region failed to inhibit growth. Thus, inhibition of cell growth by MyoD seems to occur by means of a parallel pathway to the one that leads to myogenesis. We conclude that MyoD is a prototypic gene capable of functionally activating intracellular growth inhibitory pathways. 

Category: general pathological conditions
Prognosis and prognostic factors of retinal infarction: a prospective cohort study. OBJECTIVE--To determine the prognosis and adverse prognostic factors in patients with retinal infarction due to presumed atheromatous thromboembolism or cardiogenic embolism. DESIGN--Prospective cohort study. SETTING--University hospital departments of clinical neurology. PATIENTS--99 patients with retinal infarction, without prior stroke, referred to a single neurologist between 1976 and 1986 and evaluated and followed up prospectively until death or the end of 1986 (mean follow up 4.2 years). INTERVENTIONS--Cerebral angiography (55 patients), aspirin treatment (37), oral anticoagulant treatment (eight), carotid endarterectomy (13), cardiac surgery (six), and peripheral vascular surgery (two). MAIN OUTCOME MEASURES--Death, stroke, coronary events, contralateral retinal infarction; survival analysis confined to 98 patients with retinal infarction due to presumed artheromatous thromboembolism or cardiogenic embolism (one patient with giant cell arteries excluded), and Cox's proportional hazards regression analysis, including age as a prognostic factor. RESULTS--During follow up 29 patients died (21 of vascular causes and eight of non-vascular or unknown causes), 10 had a first ever stroke, 19 had a coronary event, and only one developed contralateral retinal infarction. A coronary event accounted for more than half (59%) of the deaths whereas stroke was the cause of only one death (3%). Over the first five years after retinal infarction the actuarial average absolute risk of death was 8% per year; of stroke 2.5% per year (7.4% in the first year); of coronary events 5.3% per year, exceeding that of stroke; and of stroke, myocardial infarction, or vascular death 7.4% per year. Prognostic factors associated with an increased risk of death were increasing age, peripheral vascular disease, cardiomegaly, and carotid bruit. Adverse prognostic factors for serious vascular events were increasing age and carotid bruit for stroke, and increasing age, cardiomegaly, and carotid bruit both for coronary events and for stroke, myocardial infarction, or vascular death. CONCLUSIONS--Patients who present with retinal infarction due to presumed atherothromboembolism or cardiogenic embolism are at considerable risk of a coronary event. The risk of stroke, although high, is not so great. Not all strokes occurring after retinal infarction relate directly to disease of the ipsilateral carotid system, although this is probably the most common cause. Few patients experience contralateral retinal infarction. Non-arteritic retinal infarction should be diagnosed or confirmed by an ophthalmologist, and the long term care of patients with the condition should involve a physician who has an active interest in managing vascular disease. 

Category: general pathological conditions
Complications associated with needle localization biopsy of the breast. A review of 144 consecutive needle localization biopsies of the breast (NLBB) was performed to assess complications associated with this procedure. Thirty-four complications occurred in 27 patients. There were 11 wound infections associated with NLBB. During this time period, there were 1,583 clean general surgical operations performed, other than biopsy of the breast, yielding an over-all wound infection rate of 1.2 per cent (p less than 0.001). A trend was noted, suggesting that use of drains may have contributed to wound infection versus no drainage (25 versus 5 per cent, respectively). Electrocautery burns requiring local wound care occurred during seven biopsies and four of these patients subsequently had a wound infection develop. Four lesions required more than one excision to remove the abnormal mammary tissue, and in four, there was a failure to remove the lesion at the first operation. Fifty-three localization procedures were performed using methylene blue. In this group, only one patient required more than one biopsy to remove the abnormal mammary tissue, and there were no failures with this technique. Also, a smaller mean volume of tissue was removed in this group versus the standard NLBB (30.2 +/- 3.0 versus 53.3 +/- 4.6 cubic millimeters, respectively) (p less than 0.01). Four cardiovascular complications occurred, requiring overnight admission. All of these patients were more than 65 years old and had the procedure performed while under general anesthesia. Patient age, type of anesthesia, resident versus attending surgeon and length of procedure had no independent effect on local complication rate. 

Category: neoplasms
Pulmonary blastoma with malignant melanoma component. Pulmonary blastomas are rare primary tumors that consist of tubular or glandular structures embedded in an undifferentiated mesenchymal stroma. Focal cartilage, bone, and skeletal muscle as well as squamous differentiation have been described in these tumors. We report a unique case of a pulmonary blastoma showing a malignant melanoma component. Immunohistochemical stains for S100 protein and HMB-45 were positive in the areas of melanocytic differentiation. 

Category: neoplasms
Mild ischemia predisposes the S3 segment to gentamicin toxicity. The purpose of these studies was to determine if a functionally insignificant ischemic insult, occurring prior to gentamicin administration, enhanced gentamicin nephrotoxicity. Bilateral renal pedicle clamp studies demonstrated that 15 minutes of ischemia did not increase the plasma creatinine yet markedly enhanced gentamicin nephrotoxicity. Further studies, in uninephrectomized rats, demonstrated that following fifteen minutes of renal ischemia and four hours of reperfusion inulin clearance, FENa+ and cellular morphology were normal. This model, therefore, was used in all subsequent studies. While the plasma creatinine concentrations were normal 24 hours following 15 minutes of ischemia and only slightly increased following gentamicin administration (100 mg/kg, i.p.) gentamicin administered four hours following 15 minutes of renal ischemia resulted in significantly increased 24-hour plasma creatinine values. Light microscopic quantitation of tissue injury, performed 24 hours following experimental manipulation, was notable for S3 segment damage in the ischemia plus gentamicin group. This was not observed in either the ischemia group or the sham operated gentamicin group. Cortical gentamicin levels were elevated in the ischemia plus gentamicin group, despite similar plasma gentamicin half-lives. However, the elevation in cortical gentamicin levels was dissociated from the enhanced nephrotoxicity seen following mild ischemic injury. Taken together these data indicate that mild renal ischemia, occurring prior to gentamicin administration, greatly enhanced gentamicin nephrotoxicity with the greatest damage occurring to S3 cells. 

Category: cardiovascular diseases
Rapid and correct diagnosis of myocardial infarction: standardized case history and clinical examination provide important information for correct referral to monitored beds. The value of thorough examination of the case history as a diagnostic tool on hospitalization of patients with suspected myocardial infarction was investigated in three independent prospective studies. Use of a limited number of pain-related elements (= 'criteria'), that had already been obtained in the emergency room, could improve the decision on whether or not to admit patients to the coronary-care unit. As an example, in one of the studies, use of such criteria would have reduced the number of 'unnecessary' coronary-care-unit admissions from 298 to 162, a 46% reduction (P less than 0.001). In the same patient sample, use of the criteria could have reduced the number of patients with definite acute myocardial infarction, admitted to the general wards, from 47 to 22, a 53% reduction (P less than 0.01). These favourable results were confirmed in the two independent, smaller-scale studies. 

Category: cardiovascular diseases
Immunohistochemical alterations in basement membrane components of squamous cell carcinoma. To investigate alterations in the basement membrane (BM) in squamous cell carcinoma (SCC), we investigated 20 tumors. Four had the cytologic characteristics of Bowen's disease (SCC-BD) and 16 did not have them (SCC-NB). Tumors were studied immunohistochemically by double immunofluorescent staining by using mouse monoclonal antibodies to the core protein of heparan sulfate proteoglycan (HSPG) and chondroitin 6-sulfate glycosaminoglycan (Ch6S) as well as rabbit antiserum to laminin (LN) and type IV collagen (C-4). In well-differentiated and highly keratinized SCC-NB, LN, C-4, and HSPG could be detected in the tumor nest BM and showed no loss of continuity, but they were largely lost in poorly differentiated and poorly keratinized SCC-NB. This suggests that poorly differentiated SCC-NB cause greater enzymatic degradation of BM components than well-differentiated SCC-NB. Ch6S was detected in parts of the BM of SCC-BD, but it was absent in all SCC-NB examined. It appears that SCC-NB have lost the ability to synthesize Ch6S, and that SCC-BD degrade Ch6S although they continue to produce it. Thus, it appears that in SCC the BM is qualitatively different from that of normal epidermis, and that SCC-BD can be distinguished from SCC-NB by the Ch6S content of the BM. 

Category: neoplasms
Pathogenesis of ischemic necrosis in random-pattern skin flaps induced by long-term low-dose nicotine treatment in the rat. The objectives of the present experiments were to study the effects of long-term low-dose nicotine treatment on skin hemodynamics, viability, and microvascular morphology in 4 x 10 cm dorsally based acute random-pattern skin flaps in the rat. In addition, the reversibility of the nicotine-induced detrimental effects on skin-flap viability following cessation of nicotine treatment also was investigated. Low-dose nicotine (0.6 mg/kg) administered twice daily and subcutaneously for 24 weeks significantly (p less than 0.05) decreased skin-flap capillary blood flow, distal perfusion, and length and area of skin viability compared with the saline-treated control (n = 15). However, these same parameters in rats (n = 15) whose nicotine treatment had been withheld for 2 weeks prior to skin-flap surgery were not significantly different from the control, thus indicating that the detrimental effects of this long-term, low-dose nicotine treatment were reversible. The mean plasma level of nicotine in the nicotine-treated rats was 8.1 +/- 0.4 micrograms/dl and was within the range of plasma nicotine levels reported for human heavy cigarette smokers. Light and electron microscopic studies did not show evidence of histologic damage to the cutaneous microvasculature in acute random-pattern skin flaps and samples of normal (nonoperated) skin in nicotine-treated rats. It is concluded that long-term plasma levels of nicotine similar to those of heavy cigarette smokers are detrimental to the capillary blood flow and viability of random-pattern skin flaps in the rat. These deleterious effects can be avoided if skin flaps are raised 2 weeks after cessation of nicotine treatment. This low-dose nicotine treatment does not cause histologic damage to the microvasculature. Other pathogenic mechanisms of nicotine-induced skin flap ischemia are discussed. 

Category: general pathological conditions
Heart weights of white men 20 to 39 years of age. An analysis of 218 autopsy cases. Review of autopsy data for 218 white men between 20 and 39 years of age who died of injuries or suddenly and unexpectedly indicated a mean heart weight of 371 g. The mean for those dying of external causes was 364 g whereas the mean for those dying of natural causes was 446 g. A coefficient for heart weight expressed as a percentage of body weight was lower in heavy individuals than lightweight individuals; it ranged between 0.38% and 0.55%, with a mean of 0.48%. Heart weight, including epicardial fat, increased with age and body weight. These data may be useful to those who are called upon to investigate sudden and unexpected deaths. 

Category: general pathological conditions
Partial gastric corpectomy results in hypergastrinemia and development of gastric enterochromaffinlike-cell carcinoids in the rat. Studies in the rat have shown that partial gastric corpectomy, in which about 75% of the acid-producing oxyntic mucosa was removed, leads to markedly reduced acid secretion and a feedback increase in the plasma gastrin levels. Ten weeks after operation, the gastric enterochromaffin (ECL)-like cell density in the remaining part of the oxyntic mucosa had increased significantly. In the present study, the effects on the gastric ECL cells of lifelong persistent hypergastrinemia induced by partial (75%) corpectomy have been investigated. Seventy-five partially corpectomized rats and 40 control rats were investigated for plasma gastrin and oxyntic mucosal changes in a 124-week study. The partially corpectomized rats showed increased plasma gastrin levels after the operation; the mean increase compared with the controls was almost 10-fold during the entire study. The remaining oxyntic mucosa of the partially corpectomized rats differed from that of control rats in two respects, showing first general hypertrophy and second a marked hyperplasia of argyrophil ECL cells. The degree and incidence of these changes increased towards the end of the study, i.e., in the aging rats. An age-related increase in ECL-cell density occurred spontaneously also in the control rats but to a lesser extent than in the partially corpectomized group. ECL-cell carcinoids were found in the oxyntic mucosa of 26 of the 75 partially corpectomized rats. The first carcinoid was found 78 weeks after the beginning of the study. Six rats with carcinoids (23%) were found before week 104 (2 years) and the remainder, 20 (77%), were discovered later. No carcinoid tumor was found in the control rats. It is concluded that lifelong hypergastrinemia induced by partial corpectomy leads to the development of ECL-cell carcinoids in the oxyntic mucosa of some rats towards the end of their life span. This observation strongly supports the hypothesis that the gastric ECL-cell carcinoids found in rats treated with antisecretory drugs are caused by long-standing hypergastrinemia developing secondary to inhibition of gastric acid secretion. 

Category: general pathological conditions
Neuropsychological deficits in fetal alcohol syndrome and fetal alcohol effects. A clinical sample of 19 school-aged native children diagnosed with fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE) was compared with age- and sex-matched normal controls. Results on a battery of intellectual and neuropsychological tests indicated large and significant differences between alcohol-affected children and controls. FAS differed significantly from controls on measures of intellectual abilities, while FAE did not; FAS mean scores on these measures were significantly lower than FAE means. For neuropsychological measures, FAS were significantly poorer than controls on most measures, while FAE showed deficits compared with controls only on grip strength. The results suggest that neuropsychological measures would be a valuable supplement to intellectual measures for the purpose of assessing alcohol effects because they are less vulnerable than intellectual measures to the influence of cultural and educational experiences. 

Category: nervous system diseases
Metastatic carcinoma of the gallbladder from renal cancer presenting as intraluminal polypoid mass. We report a rare case of secondary involvement of the gallbladder by metastatic renal cell carcinoma. A 71-year-old man was diagnosed as having a polypoid mass within the gallbladder when he underwent right nephrectomy for a renal cell carcinoma. A preoperative diagnosis of simultaneous carcinoma of the gallbladder was made, and extended cholecystectomy with regional lymphadenectomy was performed five months after the initial operation. Postoperative histological examination of the polypoid mass within the gallbladder and a pancreatic mass excised during the second surgery revealed these resected tumors to be identical to the clear cell type of renal cell carcinoma. We feel that this case presents synchronous involvement of the gallbladder and pancreas by metastatic renal cell carcinoma of the right kidney. 

Category: digestive system diseases
Regional ischemia in cerebral venous hypertension due to embolic occlusion of the superior sagittal sinus in the rat. To determine the pathophysiological changes in brain tissue that characterize damage following cerebral venous hypertension, a model of cerebral venous hypertension in the rat was devised. This experimental model has the advantage of simultaneously measuring the regional changes in cerebral blood flow as well as the metabolism. The ischemic area demonstrated by the accumulation of NADH is confined to the cerebral cortex and becomes enlarged in proportion to the increase in venous pressure. This metabolic disturbance appears even in the very early period following cerebral venous hypertension. These pathophysiological features are different from those observed in the case of intracranial hypertension. 

Category: cardiovascular diseases
Postpartum hemorrhage: placenta accreta, uterine inversion, and puerperal hematomas. Puerperal hematomas, although rare, can be potentially morbid or life-threatening events. Early surgical management, including clot evacuation, layered closure, drainage, antibiotics, and fluid replacement (including blood), usually result in satisfactory outcome. Prevention is clearly preferable and often achievable with careful initial repair of episiotomies and lacerations. 

Category: general pathological conditions