Melricflash/CW_MedAbstractsAlt huggingface dataset:
Hyperhomocysteinemia: an independent risk factor for vascular disease. BACKGROUND. Hyperhomocysteinemia arising from impaired methionine metabolism, probably usually due to a deficiency of cystathionine beta-synthase, is associated with premature cerebral, peripheral, and possibly coronary vascular disease. Both the strength of this association and its independence of other risk factors for cardiovascular disease are uncertain. We studied the extent to which the association could be explained by heterozygous cystathionine beta-synthase deficiency. METHODS. We first established a diagnostic criterion for hyperhomocysteinemia by comparing peak serum levels of homocysteine after a standard methionine-loading test in 25 obligate heterozygotes with respect to cystathionine beta-synthase deficiency (whose children were known to be homozygous for homocystinuria due to this enzyme defect) with the levels in 27 unrelated age- and sex-matched normal subjects. A level of 24.0 mumol per liter or more was 92 percent sensitive and 100 percent specific in distinguishing the two groups. The peak serum homocysteine levels in these normal subjects were then compared with those in 123 patients whose vascular disease had been diagnosed before they were 55 years of age. RESULTS. Hyperhomocysteinemia was detected in 16 of 38 patients with cerebrovascular disease (42 percent), 7 of 25 with peripheral vascular disease (28 percent), and 18 of 60 with coronary vascular disease (30 percent), but in none of the 27 normal subjects. After adjustment for the effects of conventional risk factors, the lower 95 percent confidence limit for the odds ratio for vascular disease among the patients with hyperhomocysteinemia, as compared with the normal subjects, was 3.2. The geometric-mean peak serum homocysteine level was 1.33 times higher in the patients with vascular disease than in the normal subjects (P = 0.002). The presence of cystathionine beta-synthase deficiency was confirmed in 18 of 23 patients with vascular disease who had hyperhomocysteinemia. CONCLUSIONS. Hyperhomocysteinemia is an independent risk factor for vascular disease, including coronary disease, and in most instances is probably due to cystathionine beta-synthase deficiency. 

Category: cardiovascular diseases
Systemic pattern of free radical generation during coronary bypass surgery. Diffuse impairment of ventricular function after cardiac surgery may be related to the generation during reperfusion of the myocardium of free radicals derived from oxygen. Fifteen patients undergoing elective coronary bypass surgery were studied by previously described assays for peroxidised lipids and for isomerised lipids which were used as indices of free radical activity. Serial blood samples were obtained from systemic arterial, mixed venous, and coronary sinus catheters before, during, and after the ischaemic period. The patients underwent coronary artery surgery on cardiopulmonary bypass with a membrane oxygenator, relative hypothermia 30-34 degrees C, and intermittent cross-clamping of the aorta. During the ischaemic periods there were no significant changes in the indices of free radical activity. During the reperfusion phase there was a significant increase in free radical indices in arterial and mixed venous blood. A small rise in free radical indices in coronary venous blood was not statistically significant. These data indicate that free radical activity is increased in patients shortly after the cessation of cardiopulmonary bypass. The pattern of distribution between the different sampling sites suggests that much of the observed increase in isomerised and peroxidised lipids originates from tissues other than the myocardium. 

Category: general pathological conditions
Atrial fibrillation and left atrial enlargement: cause or effect? In a blinded controlled study, 58 consecutive patients with definite left atrial enlargement (M-mode dimension of at least 45 mm) were followed up after 1-2 years. The aim of the study was to examine the following: (a) the prospective risk of developing atrial fibrillation (AF); and (b) the effect of the heart rhythm on the left atrial size. Of 36 patients in sinus rhythm, one developed paroxysmal AF and one developed persistent AF during a median follow-up period of 20 months. Thus the incidence of new AF was 5% per year. Eighteen patients died before scheduled echocardiographic follow-up, but in the remaining subjects the left atrial dimension did not change significantly: the median increment was 1 mm in 20 patients who sustained sinus rhythm vs 2 mm in 16 patients with chronic AF (P greater than 0.05). Although left atrial dilatation may cause AF and vice versa, this study demonstrated that the incidence of new AF is low, despite the fact that the left atrial dimension is substantially increased. Similarly, AF per se does not appear to have any major impact on the left atrial dimension. 

Category: cardiovascular diseases
Anxiety and depression in patients with chronic urticaria and generalized pruritus. Thirty-four dermatology out-patients with chronic idiopathic urticaria and 34 with idiopathic generalized pruritus were investigated using standardized self-assessment psychological questionnaires to determine the incidence of significant symptoms of depression and anxiety. These patients were compared with age- and sex-matched but otherwise unselected general dermatology out-patients. Using the Beck depression inventory, significantly more patients with generalized pruritus (32.4%) had depressive symptomatology (score greater than 14) than controls (13.2%, P less than 0.05). Although more patients with chronic urticaria had depressive symptomatology (14.7%) than controls (4.4%), the difference was not statistically significant. Using the Speilberger state-trait anxiety inventory there were no significant differences between the patients with pruritus or urticaria and their controls with respect to state or trait anxiety scores above the upper 90% probability limit for the general population. Thus, significant depression may be expected in a substantial proportion of patients with idiopathic generalized pruritus but in a relatively small proportion of those with chronic urticaria. 

Category: general pathological conditions
Different tumor-derived p53 mutants exhibit distinct biological activities. In its wild-type form, the protein p53 can interfere with neoplastic processes. Tumor-derived cells often express mutant p53. Full-length mutant forms of p53 isolated so far from transformed mouse cells exhibit three common properties in vitro: loss of transformation-suppressing activity, gain of pronounced transforming potential, and ability to bind the heat shock protein cognate hsc70. A tumor-derived mouse p53 variant is now described, whose site of mutation corresponds to a hot spot for p53 in human tumors. While absolutely nonsuppressing, it is only weakly transforming and exhibits no detectable hsc70 binding. The data suggest that the ability of a p53 mutant to bind endogenous p53 is not the sole determinant of its oncogenic potential. The data also support the existence of gain-of-function p53 mutants. 

Category: general pathological conditions
What is the best predictor of spontaneous ventricular tachycardia and sudden death after myocardial infarction? BACKGROUND. Death during the first year after myocardial infarction is most commonly due to spontaneous ventricular tachycardia (VT) or fibrillation (VF). The purpose of this study was to compare, in a single cohort of patients, the values of inducible VT, delayed ventricular activation, low left ventricular ejection fraction, high-grade ventricular ectopy, and ST segment displacement on exercise in predicting electrical events (witnessed instantaneous death and spontaneous VT or VF) during the first year after myocardial infarction. METHODS AND RESULTS. Three hundred sixty one patients aged less than 71 years underwent electrophysiological study, signal-averaged electrocardiogram, gated blood-pool scan, 24 hour ambulatory electrocardiographic monitoring, and exercise testing 1-2 weeks after myocardial infarction and were then followed up for at least 1 year. There were 34 deaths (eight witnessed instantaneous, 26 other), and nine patients survived one or more episodes of spontaneous VF or VT. Patients with inducible VT were 15.2 times more likely to suffer electrical events than patients without inducible VT. No proportional-hazards model excluding inducible VT was as good a predictor of electrical events as was inducible VT alone. CONCLUSIONS. Inducible VT at electrophysiological study was the single best predictor of spontaneous VT and sudden death after myocardial infarction. 

Category: general pathological conditions
Normal angiograms and carotid pathology. Nonstenotic ulcerated atherosclerotic plaques of the carotid arteries may be associated with symptoms of transient ischemic attacks, amaurosis fugax, and stroke. Preoperative evaluation of patients with these symptoms has traditionally included ultrasound and arch aortography angiograms of the area of the carotid bifurcation. Recent evidence has shown that ultrasound is more accurate in detection and morphologic delineation of these nonstenotic lesions. We analyzed the hospital records of 21 patients with ultrasonographic evidence of disease in whom arteriograms were negative. The patient group comprised 15 men and six women, with an average of 66 years. All patients had symptoms of hemispheric transient ischemic attacks and were evaluated with B-mode ultrasound and arteriography. Ultrasound was positive and arteriogram "negative" in all of the patients (i.e., described by the radiologist as without hemodynamic significant disease or ulceration, or as normal). The ultrasound diagnosis was confirmed at operation with findings of 20 to 50 per cent stenosis and ulcerative plaques. At retrospective review of the arteriograms, three ulcerations were found in the 21 patients. We conclude that B-mode ultrasound better defines nonstenotic ulcerative lesions and decisions to perform carotid endarterectomy may be based on either positive test. An ulcerative plaque by B-mode ultrasound and appropriate symptoms, therefore, may not require angiography before operation. 

Category: cardiovascular diseases
The effect of cesarean delivery on birth outcome in very low birth weight infants. National Institute of Child Health and Human Development Neonatal Research Network. To determine whether cesarean delivery is associated with a better outcome than vaginal delivery for infants weighing less than 1500 g (very low birth weight), we examined neonatal mortality and the incidence of intraventricular hemorrhage (IVH) in 1765 very low birth weight inborn infants admitted to seven neonatal intensive care centers. The cesarean rate was 32.5% for infants weighing 501-750 g and 52.4% for infants weighing 751-1000 g. The neonatal death rate was 53.1% for infants weighing 501-750 g delivered by cesarean, compared with 64.3% for vaginally born infants (P = .046). However, for infants weighing 1001-1250 g, the neonatal death rate for infants delivered by cesarean was 14.4%, compared with 7.8% for infants born vaginally (P = .02). The incidence of IVH was significantly lower in infants born by cesarean than in those born vaginally only in the 1251-1500-g birth weight interval (11.8 versus 18.9%; P = .03). Compared with women delivering vaginally, those delivered by cesarean were more likely to attain a higher mean gestation, to have preeclampsia, and to have a breech presentation, and less likely to be in labor. After adjusting by logistic regression for gestational age, preeclampsia, breech presentation, presence or absence of labor, and for center effects, the odds ratio for neonatal death was 1.00 (95% confidence interval 0.71-1.41); for IVH, the odds ratio was 0.85 (95% confidence interval 0.61-1.19). These data suggest that after accounting for certain maternal and fetal factors, cesarean delivery is not associated with a lower risk of either mortality or IVH. 

Category: general pathological conditions
Surveillance of in situ infrainguinal bypass grafts: conventional vs. color flow duplex ultrasonography. Surveillance of in situ saphenous vein bypass grafts with duplex scanning detects graft abnormalities which may lead to graft thrombosis. Correction of these defects, while grafts are still patent, potentially improves overall graft patency. In this study we compared color flow and conventional duplex to determine whether color flow provided additional information not obtainable by conventional duplex examination. The primary patency rate (patency maintained without intervention) for all 51 cases was 76% (39/51). The secondary patency rate (patency maintained by identification and correction of graft defects before failure) was 88% (45/51). Duplex scanning reduced the graft failure rate by 50%. Color flow and conventional duplex examination provided the same information regarding incipient graft failure. In 20 patients monitored with both techniques, the same number of proximal (100%) and distal (90%) anastomoses were imaged. The same number of graft defects (three vein graft stenoses, one proximal femoral artery stenosis) were identified. Velocity data obtained using the two techniques (peak systolic velocity in an area of stenosis and the duplex velocity ratio) were not always the same, making calculation of percent stenosis from this data inaccurate. Color flow duplex is useful in monitoring graft patency, but provides no additional information over that provided by conventional scanning. 

Category: general pathological conditions
Outpatient laparoscopic laser cholecystectomy. Laparoscopic laser cholecystectomy has been performed clinically in the United States since 1988. After refinement of the technique, the procedure was offered on an outpatient basis. Eighty-three patients underwent laparoscopic laser cholecystectomy during the study period. Thirty-seven (45%) had the procedure as an outpatient. Younger patients were more suited for the outpatient procedure and those without previous surgery were more likely to have the procedure done as an outpatient. Weight, operating time, and gallbladder pathology were similar, although patients with acute inflammation of the gallbladder were more likely to require hospitalization. The primary reason for patient admission was patient preference. 

Category: digestive system diseases
The effect of large uterine fibroids on urinary bladder function and symptoms. Fourteen patients with large uterine fibroids and urinary symptoms were treated with monthly injections of [D-Trp6]-luteinizing hormone-releasing hormone microcapsules. The average uterine size before treatment was 728 ml; it dropped to 323 ml (a drop of 55%) after treatment. Urinary symptoms of diurnal frequency disappeared in 11 of 12 patients (p less than 0.005) after the reduction of uterine size. Urgency decreased in 11 of 13 (p less than 0.005) and nocturia in eight of 10 (p less than 0.02). No differences were found before and after treatment in the symptoms of urge incontinence and stress incontinence in the cystometric and urethral pressure profile measurements. Urinary symptoms of frequency, urgency, and nocturia may be caused by the direct pressure exerted on the bladder by the enlarged uterus. Symptoms of urge incontinence and stress incontinence deserve a more specific treatment as they are not related to uterine size. 

Category: neoplasms
Surgical aspects of malaria. The spread of drug-resistant organisms and increased international travel makes malaria a disorder of ever-increasing importance. This report reviews those aspects of malaria of surgical relevance. The importance of the spleen in host defence against malaria and other infections makes splenic preservation desirable whenever possible after rupture of the spleen. Tropical splenomegaly is caused by an abnormal immune response to malaria and is best managed medically. Careful selection of blood donors is essential to prevent transfusion malaria, and routine antimalarial prophylaxis is indicated for blood recipients in many endemic areas. The risk of postoperative malaria may justify chemoprophylaxis in certain patients. 

Category: general pathological conditions
Extracorporeal cholecystolithotripsy without oral chemolitholysis. One hundred thirty-six patients completed extracorporeal biliary lithotripsy (EBL) for symptomatic cholecystolithiasis. Sonographic evidence of complete clearance of all stone fragments was the only criterion for treatment success, which occurred in 32 of the 71 patients (45%) followed up for 24 weeks and in 36 of the 59 patients (61%) followed up for 52 weeks. The authors' protocol varied from protocols of other researchers primarily in that no adjuvant chemolitholysis was used. However, the number of treatment sessions and total number of shock waves (a maximum of 4,000 shock waves per treatment session, 12,000 shock waves in a patient demonstrating no significant fragmentation, and 20,000 shock waves in a patient whose stones responded well to fragmentation) was higher than those in other reports. The results of treatment and complication rates in this study are comparable with those at centers using both shock-wave lithotripsy and chemotherapy. The authors conclude that EBL is developing into an important alternative to surgery, which was obviated in all patients with complete clearance of fragments from the gallbladder. 

Category: digestive system diseases
Skewflap versus long posterior flap in below-knee amputations: multicenter trial. A multicenter trial of alternative techniques for below-knee amputation is described in which surgeons in 11 centers randomized 191 patients with end-stage occlusive vascular disease to two different methods of stump construction. The skewflap technique was performed in 98 and the long posterior flap was performed in 93. The two groups were well matched in respect to age, sex, smoking, diabetes, and indications for amputation. Early outcome was compared in terms of 30-day mortality rate: skew 11 (11%) deaths versus long posterior flap 16 (17%); the state of the wound at 1 week (primary healing 60% in both groups); the need for surgical revision at the same level 7 (7%) versus 7 (8%), and revision to a higher level 10 (10%) versus 7 (8%). Follow-up information at 6 months was available from records or by mailed questionnaire in 188 (98%) at 6 months, 20 died during that interval. It showed that a prosthetic limb was fitted to 64 (84%) of skew flaps and 50 (77%) of long posterior flaps. Walking, alone or with support, was achieved in 59 (78%) and 46 (71%), respectively. None of these differences reached statistical significance. It is concluded that the skew flap is just as effective as the long posterior flap and is an excellent option for below-knee amputation. 

Category: cardiovascular diseases
Prognostic determinants in extracorporeal membrane oxygenation for respiratory failure in newborns. Extracorporeal membrane oxygenation (ECMO) is becoming an accepted therapeutic modality for newborn respiratory failure, but there is little information available regarding the prognostic determinants with this technique. One hundred thirty-five newborns treated with ECMO over a 4-year period were critically analyzed with regard to the influence that birth weight, gestational age, age at initiation of ECMO, best blood gases before ECMO, number of hours on ECMO, renal failure, intracerebral hemorrhage, and long-distance air transport had on survival. Infants with meconium aspiration and those undergoing long-distance transfer showed significant differences in blood gases before ECMO, with survivors having more normal pH and carbon dioxide tension values. Intracerebral hemorrhage and renal failure that developed during ECMO were grave prognostic signs, with few survivors in either group. These data show that ability to ventilate patients before ECMO, giving normal carbon dioxide tension and pH values, is an important prognostic sign in infants with meconium aspiration and undergoing long-distance transfer for ECMO, whereas renal failure and intracerebral hemorrhage are usually lethal complications of ECMO. Each center performing ECMO should continually reevaluate this invasive technique and its results and complications. 

Category: cardiovascular diseases
Renal function in obstructive jaundice in man: cholangiocarcinoma model. Renal function with respect to water clearance and renal hemodynamics was studied in 15 patients with obstructive jaundice due to cholangiocarcinoma. The results were compared with those of the control normal subjects. There was no change in renal function in the patients with mild to moderate jaundice, with total serum bilirubin from 8.0 to 15.1 mg/dl. Increased urinary sodium excretion and decreased free water and negative water clearances were observed in the patients with severe jaundice with total serum bilirubin from 27.0 to 40.4 mg/dl and normal serum albumin. Renal blood flow was normal, but creatinine clearance was decreased. In severely jaundiced patients with serum bilirubin from 30.5 to 40.1 mg/dl and hypoalbuminemia urinary sodium excretion, free water clearance, negative water clearance, renal blood flow and creatinine clearance were decreased. There was salt and water retention in this group. The findings suggest that in severe jaundice there is inhibition of sodium chloride reabsorption in the thick ascending limb of Henle's loop. ADH and increased hydraulic conductivity of the collecting tubules possibly contribute to decreased free water clearance. In severely jaundiced patients with hypoalbuminemia this salt losing effect is converted to salt retention by increased proximal tubular reabsorption of sodium. 

Category: neoplasms
Causes and consequences of blood pressure alterations in obstructive sleep apnea. The obstructive sleep apnea (OSA) syndrome has been considered to be a cause of both transient blood pressure elevations during sleep and sustained hypertension during the awake state. The purpose of this review was to examine critically the existing literature regarding (1) the blood pressure alterations associated with OSA, (2) causal mechanisms relating specific blood pressure alterations to OSA, and (3) potential consequences of the systemic circulatory abnormalities associated with OSA. Particular attention was directed at studies that assessed the prevalence of OSA in patients with hypertension and that examined the effects on blood pressure of treatment of OSA. We conclude that patients with OSA have abnormal sleep blood pressure patterns, manifested most frequently by apnea-associated blood pressure elevations. Confounding factors such as obesity and antihypertensive drug therapy, and conflicting evidence regarding changes in daytime blood pressure after therapy for OSA, make it premature to conclude that OSA and daytime hypertension are directly associated. Circumstantial evidence suggests that the blood pressure alterations that occur during sleep could contribute to the high cardiovascular morbidity in patients with OSA. Further research into the relationship between OSA and hypertension should improve the future care of patients with these conditions and enhance our understanding of cardiopulmonary pathophysiology. 

Category: nervous system diseases