Melricflash/CW_MedAbstractsAlt huggingface dataset:
Immune responses to allogeneic and xenogeneic implants of collagen and collagen derivatives. Whereas xenogeneic collagen has provided a safe and effective biomaterial for numerous medical applications, there are few instances in which data permit the correlation of the immunologic profile of well-defined devices with their clinical sequelae. A major exception is the use of injectable bovine dermal collagen for soft-tissue contour correction. The low incidence of hypersensitivity has been studied in the context of clinical efficacy and safety with several devices. The findings indicate that such immunity usually results in the manifestation of local symptoms of dermal inflammation at sites of treatment that resolve as the implant is resorbed by the host. In contrast, more immunogenic hemostatic agents may elicit a more frequent or vigorous immune response that is not clinically visible or relevant in that application. Recent experiences with collagen-based devices for the repair and regeneration of bone have also demonstrated that the presence of immunity to their collagenous or non-collagenous components does not necessarily predict adverse clinical sequelae. Indeed, numerous specific data indicate that this immunity can exist as an epiphenomenon with no effect on osteogenesis. To get a true composite picture of biocompatibility, significant steps must be taken to characterize biomaterials properly and to ensure that immunologic, clinical, histologic, and other pertinent laboratory data are viewed in relation to one another and not in isolation. 

Category: general pathological conditions
Hemorrhoidectomy during pregnancy: risk or relief? Acute hemorrhoidal crisis can occur in the pregnant female. When medical therapy fails to relieve pain, operative intervention may be necessary. The surgeon, however, may be reluctant to operate due to potential complications to the mother and fetus. From July 1983 to July 1989, hemorrhoidectomy was performed in 25 of 12,455 pregnant women (0.2 percent) who delivered in our institution. Twenty-two women were in their third trimester, 80 percent were multiparous, and each had a remote history of hemorrhoidal symptoms, including intermittent pain, bleeding, and protrusion. Closed hemorrhoidectomy was performed under local anesthesia. The surgery was directed at removing only symptomatic disease, which included three quadrants in 14 patients, two quadrants in seven patients, and one quadrant in four patients. All patients experienced relief of intractable pain the day after surgery, except one patient who required a hemostatic packing during the immediate post-operative period. There were no other maternal or fetal complications. Subsequent follow-up for anorectal disease ranged from 6 months to 6 years. Six (24 percent) patients required additional hemorrhoid treatment. Hemorrhoidectomy in selected pregnant patients is safe in our experience. 

Category: general pathological conditions
Anterior cervical discectomy and fusion. A retrospective review of 94 patients who had undergone anterior cervical discectomy and fusion was performed to analyze the result in patients who had a diagnosis of posterolateral spondylosis, disc herniation, or both. Although in 23 of 94 patients additional adjacent asymptomatic levels of spondylosis were noted, only the symptomatic levels were addressed in the 94 cases. Postoperatively two cases of dysphagia were noted, as well as a 4% pseudarthrosis rate. There was an 88% good or excellent result when no additional spondylosis was present, but only a 60% good or excellent result when just the symptomatic levels were addressed, leaving unoperated adjacent levels of spondylosis. 

Category: general pathological conditions
Sedation for upper gastrointestinal endoscopy: results of a nationwide survey. A postal questionnaire inquiring about routine sedation and premedication practice for upper gastrointestinal endoscopy was sent to 1048 doctors. Of 665 appropriate returns, 81% were from consultant physicians and surgeons. Most endoscopists (90%) reported using an intravenous benzodiazepine for at least three quarters of endoscopies and 54% of physicians and 69% of surgeons always did so. Midazolam was the intravenous sedative used by a third of all respondents and 13% also used an additional intravenous agent, usually pethidine. Over the previous two years a total of 119 respiratory arrests, 37 cardiac arrests, and 52 deaths were identified. Adverse outcomes were reported more frequently by consultant physicians, by those who 'titrated' the intravenous sedative, and by those who used an additional intravenous agent, but were reported equally frequently by endoscopists using midazolam and endoscopists using diazepam. There is an urgent need for a prospective study to identify the circumstances and risk factors associated with adverse outcomes related to endoscopy. 

Category: cardiovascular diseases
Noncoordinate regulation of alpha-1 adrenoreceptor coupling and reexpression of alpha skeletal actin in myocardial infarction-induced left ventricular failure in rats. To determine the effects of myocardial infarction-induced left ventricular failure on the regulation of surface alpha-1 adrenoreceptors and signal transduction, large infarcts were produced in rats and the animals killed seven days later. After the documentation of impaired left ventricular pump performance, radioligand binding studies of the alpha-1 adrenoreceptor, norepinephrine-stimulated phosphoinositol turnover, and ADP ribosylation of 41 kD substrate by pertussis toxin were examined in the hypertrophying unaffected myocardium. Moreover, the expression of sarcomeric actin isoforms was analyzed by Northern blots and hybridization with specific oligonucleotide probes. Alpha-1 adrenoreceptor density was found not to be altered in membranes obtained from the spared left ventricular tissue, whereas phosphoinositol turnover was increased 3.1-fold in the viable myocytes of infarcted hearts. Furthermore, pertussis toxin substrate was augmented 2.5-fold in membranes prepared from the surviving left ventricular myocardium. Finally, an upregulation of the skeletal actin isoform was detected in the tissue of the failing left ventricle. In conclusion, the possibility is raised that in the presence of severe myocardial dysfunction and ongoing reactive hypertrophy, effector pathways linked to the alpha-1 adrenoreceptor may stimulate the myocyte hypertrophic response which would tend to normalize cardiac hemodynamics. The reexpression of alpha skeletal actin may be a molecular indicator of the persistance of an overload on the myocardium. 

Category: cardiovascular diseases
Analysis of the Medtronic Intact bioprosthetic valve. Effects of "zero-pressure" fixation. The long-term performance of current-design porcine xenograft valves has not been satisfactory. These valves are generally fixed at "low pressures" of about 3 to 5 mm Hg. The Medtronic Intact (Medtronic, Inc., Minneapolis, Minn.) valve is fixed at "zero pressure" and is proposed as a better alternative to existing xenograft valves. A mechanical analysis of this valve has been carried out to determine if the Intact valve differs significantly from the low-pressure fixed xenograft. Twelve circumferential strips of tissue 5 mm wide were cut from the leaflets of four clinical-grade Intact valves. Their stress/strain, stress relaxation, and flexural behavior were examined mechanically and histologically. The Intact valve was more extensible than the low-pressure fixed xenograft (22% versus 12% strain, p less than 0.001), relaxed faster (p less than 0.001), and was more pliable than the xenograft (p less than 0.05). It did not, however, buckle less than did the low-pressure fixed xenograft during enforced bending, and it buckled significantly more than did fresh porcine aortic valve tissue (p less than 0.001). The Intact valve also relaxed significantly more slowly than did the fresh tissue (p less than 0.05). Its bending stiffness had a stronger dependence on leaflet thickness than the bending thickness of fresh tissue had (p less than 0.001) but a weaker dependence than the bending thickness of the low-pressure fixed xenograft material had (p less than 0.001). The Intact valve demonstrated a very large variability in extensibility, bending stiffness, and buckling behavior, with little correlation between these parameters. Some valves appeared to have wrinkled leaflets; others were likely fixed at different pressures. The shrinkage of the leaflet material at these low fixation pressures is likely important, since it can modify the elastic behavior of the valve cusps. Overall, the Intact valve had a more "natural" elastic behavior than had low-pressure fixed xenograft, and it should therefore experience lower stresses during normal valve function. It can be concluded that zero-pressure fixation does preserve many of the desirable stress-reducing properties of aortic valve tissue. 

Category: general pathological conditions
Left ventricular rupture complicating percutaneous mitral commissurotomy: salvage using percutaneous cardiopulmonary bypass support. Left ventricular rupture resulting in death has been reported to be a complication of percutaneous mitral commissurotomy. We report a 71-year-old man in whom a left ventricular rupture occurred during percutaneous mitral commissurotomy and resulted in hemodynamic collapse due to acute cardiac tamponade. The patient was stabilized using percutaneously instituted cardiopulmonary bypass support with subsequent repair of the left ventricle and successful mitral valve replacement. Three months later this patient remains in New York Heart Class I. 

Category: cardiovascular diseases
Perianal appearances associated with constipation. The perianal appearances were studied prospectively of 136 constipated children (mean age 3.9 years, 67 boys, 69 girls). Anal dilatation, fissures, tags, warts, perianal oedema, redness, blueness, and veins were recorded. It was noted whether dilatation occurred immediately or at 30 and 60 seconds with the buttocks minimally separated, and on subsequent firm lateral traction of the buttocks. The degree of faecal loading was assessed in all children. Anal dilatation was found in 24 (18%) and first appeared on lateral traction in eight (6%). In three quarters of the children with dilatation faecal loading or perianal signs were present. Fissures were found in 35 (26%) children and tags in seven (5%). Perianal redness was more likely to be associated with fissures, and blueness with dilatation. We conclude that there are no pathognomonic perianal signs in childhood constipation and that the technique of anal examination should be standardised. 

Category: digestive system diseases
Magnetic resonance imaging for ineffectual tarsal tunnel surgical treatment. Tarsal tunnel syndrome (TTS) is an entrapment neuropathy caused by compression of the posterior tibial nerve beneath the ankle flexor retinaculum. Treatment of TTS consists of surgical release of the retinaculum. The failure rate is 10%-20%. Magnetic resonance (MR) imaging was used to evaluate a patient with an unsatisfactory response. MR imaging demonstrated incompleteness of the surgical release of the flexor retinaculum. 

Category: nervous system diseases
Analysis of base station morphine orders: assessment of supervising physician consistency. Paramedic contact with a base station should gemerate consistent recommendations reflecting a consensus of base station physician care. In our urban EMS system, paramedics must contact a single base station to provide morphine sulfate (MS) for a patient with chest pain. We performed a retrospective cohort analysis of all prehospital MS requests for chest pain to determine the consistency of the circumstances for which the paramedic team was refused MS. These MS requests represented 123 of the 1,715 (7%) on-line physician consultations during the 6-month study. Only 15 of the 123 (12%) MS requests were refused. Neither the mean patient age, sex distribution, or presenting vital signs correlated with MS refusal. A maximum estimate of transport time to the hospital of less than or equal to 5 minutes was noted for 7 of 15 (47%) medication refusals compared to only 11 of 96 (11%) approvals with documented estimated transport times (P less than or equal to 0.005). A simultaneous request for nitroglycerin (NTG) was noted for 6 of the 15 (40%) medication refusals and 15 of the 108 (14%) approvals (P less than 0.05). We found refusal of MS administration to be uncommon. Supervising physicians tended to refuse MS when the transport time was short and when NTG was requested for concomitant administration. We also noted physician inconsistencies in refusal scenarios. These findings can guide physician consensus development to avoid sending mixed messages to paramedics. 

Category: general pathological conditions
Flow cytometric DNA-ploidy analysis of synchronously occurring multiple malignant tumors of the female genital tract. In this study the authors applied flow cytometric DNA-ploidy analysis to multiple female genital tract malignant tumors in 43 patients, most of whom (n = 37) had bilateral ovarian cancer. An algorithm was developed for calculation of the likelihood ratio of the probabilities that measured DNA index differences between multiple tumor localizations within the same patient could be attributed to measurement variation or to true biologic DNA content differences. The results of this statistical analysis show that in 72% of the cases (31 of 43) this probability ratio exceeded 1. Because the probability that two independent tumors will have a near-identical aneuploid DNA content is very low, this finding supports a metastatic process rather than the occurrence of multiple primary tumors in these patients. Thus, flow cytometric DNA-ploidy analysis can be helpful in the identification of metastatic disease in patients with multiple female genital tract malignant tumors. 

Category: neoplasms
Successful mitral valvuloplasty using the Inoue balloon in a patient with mitral stenosis associated with subvalvular fibrosis and reduced left ventricular inflow cavity: a case report. Percutaneous transvenous mitral valvuloplasty (PTMV) was performed with two cylindric pigtail balloon catheters in a 52-year-old woman with symptomatic mitral stenosis. The subvalvular apparatus was fibrous with welded chordae and the subvalvular left ventricular space was markedly reduced. As a result of this distorted anatomy, during the inflations, the two balloons constantly slipped back into the left atrium before full inflation was obtained. After the procedure, the mitral valve area (MVA), as estimated by echo-doppler (ED), increased from 1.00 to 1.34 cm2. After 2 months of mild clinical improvement, the patient again became symptomatic and ED examination showed a MVA of 1.25 cm2. A second PTMV was performed with an Inoue balloon, the entire procedure taking less than 1 hour. A stable position of the Inoue balloon and complete dilatation were achieved. ED examination showed a mitral valve area of 2.30 cm2. There was no mitral regurgitation nor atrial septal defect. After 3 months, she has only N.Y.H.A. class I symptoms and MVA, as estimated by ED, was 2.40 cm2. 

Category: cardiovascular diseases
Late complications in pediatric cardiac transplant recipients. Late complications occurring more than 3 months after cardiac transplantation were analyzed in 29 pediatric patients in whom 31 cardiac transplantations were performed. Age at transplantation ranged from 3 months to 18 years (mean, 11.3 years) with follow-up ranging from 3.5 to 54 months (mean, 21.6 months). There were seven late deaths and two patients with retransplantations. Of nine grafts lost, eight were due to acute rejection, and one was due to coronary disease. Four of the grafts lost were secondary to patient noncompliance with prescribed immunosuppression. The mean rejection frequency more than 1 year after cardiac transplantation was significantly higher in those patients who eventually lost their grafts; however, these patients could not be distinguished by their rejection frequency in the first year. Eight patients had coronary disease, with five diagnosed at autopsy, two at cardiac retransplantation, and one by angiography. All eight patients were on double immunosuppression; none of the 19 patients on triple therapy had coronary disease with similar follow-up. There were 12 serious infections in eight patients (four associated with OKT3) with no deaths. Five patients had arrhythmias requiring treatment including two pacemakers; four of the five were associated with rejection episodes. Twelve of 29 patients developed early hypertension, and five developed late hypertension (greater than 1 year). There were two malignancies; one patient with Hodgkin's lymphoma was cured with chemotherapy, and one patient with histiocytic lymphoma was discovered at autopsy. Two patients had cholecystectomies, and five patients required laser gingivectomies. 

Category: general pathological conditions
Hepatic lesions in the rabbit induced by acoustic cavitation. Tissue damage during shock-wave lithotripsy is presumably secondary to cavitation phenomena involving the collapsus of gas bubbles in a fluid. To enhance shock-wave-related hepatic lesions, intravascular gas microbubbles were administered. Three groups of eight rabbits each received either 500 shock waves focused on the right hepatic lobe (group 1), gas microbubbles as a mixture of 50 cm3 of air with 50 cm3 of gelatin infused through an arterial catheter (group 2), or 500 shock waves and gas microbubbles simultaneously (group 3). In group 1, two animals had two to three subcapsular hepatic hematomas (diameter, less than 5 mm) and five had one to five intraparenchymal hematomas (less than 1 mm). In group 2, a moderate liver congestion was observed in three animals. In group 3, all animals had numerous subcapsular and intraperenchymal hematomas (2-30 mm). The hematomas were centered around the portal spaces, associated with lacunae (0.5-5 mm in diameter). Hematomas were also present on the anterior wall of intraabdominal organs. It was concluded that intravascular infusion of gas microbubbles into the path of a shock-wave generator dramatically enhances tissue damage. This technique, potentially useful in the treatment of hepatic tumors, needs refinement to confine lesions in a more uniform pattern to the targeted parenchyma. 

Category: general pathological conditions
Multicenter trial of L-carnitine in maintenance hemodialysis patients. II. Clinical and biochemical effects. Since carnitine deficiency has been reported in some patients undergoing maintenance hemodialysis, we studied the effects of intravenous infusion of L-carnitine or placebo at the end of each dialysis treatment. The trial, which lasted seven months (one month baseline, 6 months treatment) was multicenter, double blind, placebo controlled, and randomized. Eighty-two long-term hemodialysis patients, who were given either carnitine (N = 38) or placebo (N = 44), completed this study. In each group, clinical and biochemical parameters during treatment were compared with baseline values. Intra-dialytic hypotension and muscle cramps were reduced only in the carnitine treated group, while improvement in post-dialysis asthenia was noticed in both carnitine and placebo groups. Maximal oxygen consumption, measured during a progressive work exercise test, improved significantly in the carnitine group (111 +/- 50 ml/min. P less than 0.03) and was unchanged in the placebo group. L-carnitine treatment was associated with a significant drop in pre-dialysis concentrations of serum urea nitrogen, creatinine and phosphorus (means +/- SEM, 101 +/- 4.5 to 84 +/- 3.9, 16.7 +/- 0.67 to 14.7 +/- 0.64, and 6.4 +/- 0.3 to 5.5 +/- 0.4 mg/dl, respectively, P less than 0.004). No significant changes in any of these variables were noticed in the placebo group. Mid-arm circumference and triceps skinfold thickness were measured in 11 carnitine and 13 placebo treated patients. Calculated mid-arm muscle area increased in the carnitine patients (41.37 +/- 2.68 to 45.6 +/- 2.82 cm2, P = 0.05) and remained unchanged in the placebo patients. 

Category: cardiovascular diseases
Myocarditis simulating acute transmural myocardial infarction. A patient with cardiogenic shock had typical electrocardiographic findings of acute anterior transmural myocardial infarction. Cardiac catheterization revealed normal coronary arteries and severe biventricular failure. Postmortem examination confirmed normal coronary arteries; acute myocarditis, but no evidence for infarction, was found. Electrocardiographic changes of myocarditis may be indistinguishable from acute transmural infarction. In suspected cases, cardiac catheterization should be considered prior to thrombolytic therapy. 

Category: general pathological conditions
Beta camera for static and dynamic imaging of charged-particle emitting radionuclides in biologic samples. A detection system based on microchannel plates has been constructed to image charged particles emitted by radionuclides in biomedical samples. This technique has significant advantages over conventional film autoradiography for investigating the distribution of radiolabeled compounds: shorter acquisition times due to the high sensitivity, easier sample handling, direct quantification and the ability to perform dynamic studies. The detector performance shows a spatial resolution of 0.9 mm for carbon-14 (14C) (0.156 MeV), good linearity and homogeneity. The noise level is below 50/(cm2.sec). Successful imaging with this system has been performed with beta-emitters 14C, sulfur-35 (35S), iodine-131 (131I), yttrium-90 (90Y), and positron emitters gallium-68 (68Ga), and fluorine-18 (18F). Dynamic studies of axonal transport of 35S-methionine in a nerve, and static images of 90Y-labeled monoclonal antibodies in slices of tumors are presented. The system shows promise for rapid quantitative imaging of charged-particle emitting radionuclides in small biologic samples. 

Category: neoplasms
Endoscopic laser surgery for early glottic carcinoma: a clinical and experimental study. The purpose of this study is to define the indications for using the CO2 laser for the treatment of early glottic cancer. For this purpose, 52 consecutive laser resections of Tis to T2 vocal cord carcinomas were studied prospectively. In addition, laser resection was performed in eight human cadaver larynges, which were then examined histologically using whole organ sections. Both tumor size and tumor location had important influences on tumor resectability by laser. All of the Tis, 78% of T1, and one of four T2 carcinomas were successfully treated by laser surgery alone. Of the 10 carcinomas involving the anterior commissure, only four could completely be resected with the laser; of these four, two recurred in the anterior commissure. This finding is corroborated by the histologic study, which clearly shows that anterior commissure resection poses problems. The only laser resection complication of early glottic cancer was persistent hoarseness in one third of the patients. It is concluded that CO2 laser resection is a safe and effective alternative treatment for patients with Tis and T1 glottic carcinoma, provided the anterior commissure is free of tumor. 

Category: neoplasms