123rc/medical_text huggingface dataset:
Phase II trial of piritrexim in metastatic melanoma using intermittent, low-dose administration. A phase II trial of piritrexim (2,4-diamino-6[2,5-dimethoxybenzyl]-5-methyl pyrido-[2,3d] pyrimidine, 301U74; PTX) was conducted for patients with metastatic malignant melanoma using an intermittent, low-dose oral administration schedule. PTX was administered at a starting dose of 25 mg orally three times per day for 5 days weekly for 3 weeks followed by 1 week of rest. Thirty-one patients were entered onto the study. Among 31 patients assessable for response, there were two complete responses (CRs) and five partial responses (PRs) for a response rate (CR plus PR) of 23% (95% confidence limit, 10% to 42%). Five responses occurred in soft tissue lesions, and two responses occurred in lung lesions. The initial dose schedule was well tolerated. The dose-limiting toxicity was myelosuppression. PTX administered in this schedule appears to be active against malignant melanoma. Further clinical trials to confirm these results are underway.
Multiple-pulse stimulation and dantrolene in malignant hyperthermia. A potentially fatal condition, yet preventable, malignant hyperthermia (MH) lacks a satisfactory noninvasive diagnostic test. Studying the effects of intravenous dantrolene (3 mg/kg) on electrically stimulated skeletal muscle, we found that this approach does not conclusively distinguish between normal humans and those susceptible to malignant hyperthermia but nonetheless yielded important information about the action of dantrolene in man and in MH. Supramaximal single- and multiple-pulse stimulation of the common peroneal nerve produced stable torque responses of the dorsiflexor muscles (monitored in vivo), which dantrolene suppressed. With the multiple-pulse stimulation (5-6 pulses) this torque suppression was significantly less in MH-susceptible subjects than in control subjects. This distinction, also observed in MH swine, confirms this animal as a good model for human MH. That dantrolene's effect in MH can be more completely reversed with high frequency stimulation is intriguing; presumably, excitation-contraction coupling differs in MH and normal muscle.
Comparison of a 3- and 6-mm incision in combined phacoemulsification and trabeculectomy. We studied 216 eyes of 160 patients who underwent combined phacoemulsification and posterior chamber intraocular lens implantation with trabeculectomy. The mean follow-up was 18.7 months, with a minimum follow-up of six months. To assess the safety and efficacy of a recently developed 3-mm incision procedure with foldable intraocular lens implantation (phacotrabeculectomy), we compared 104 eyes subjected to this procedure with 112 eyes subjected to a 6-mm procedure at different follow-up periods. Intraocular pressure control (less than 21 mm Hg) was attained in 44 of 46 eyes (96%) in the 3-mm group and 71 of 76 eyes (93%) in the 6-mm group at one year postoperatively. Visual acuity of 20/40 or better was attained in 40 of 46 eyes (87%) in the 3-mm group and 66 of 76 eyes (87%) in the 6-mm group. The incidence of postoperative complication was significantly lower (P less than .001) and visual acuity in the early postoperative period was significantly better (P less than .01) in the 3-mm incision group than in the comparison group.
Evidence of a local immune activation in cystic brain tumors. The fluid of cystic brain tumors was characterized with regard to the protein content. In most malignant tumors, the concentrations of immunoglobulins G and M (IgG and IgM) were higher relative to other proteins in the cyst fluid than in the serum of the same patient. A markedly elevated ratio of monomeric to pentameric IgM was detected in the cyst fluid of two patients with glioblastomas. The results indicate a local immunoglobulin synthesis in malignant cystic brain tumors. It is hypothesized that higher-than-expected concentrations of IgG and IgM in cyst fluid as compared to plasma are a sign of an ongoing immune response triggered by the tumor.
Species-dependent effects of adenosine on heart rate and atrioventricular nodal conduction. Mechanism and physiological implications. This study 1) compares the negative chronotropic and dromotropic actions of adenosine in guinea pig, rat, and rabbit hearts; 2) investigates the mechanism(s) for the different responses; and 3) determines the physiological implications. Isolated perfused hearts were instrumented for measurement of atrial rate and atrioventricular (AV) nodal conduction time. Differences in metabolism of adenosine were determined in the absence and presence of dipyridamole (nucleoside uptake blocker) and erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA, adenosine deaminase inhibitor). Dipyridamole plus EHNA decreased adenosine's EC50 for the negative dromotropic effect by 14-fold in guinea pig heart and 1.6-fold in rat heart. This is consistent with the greater number of [3H]nitrobenzylthioinosine binding sites measured in membranes from guinea pig (1,231 +/- 68 fmol/mg protein) compared with rat (302 +/- 31 fmol/mg protein) and rabbit (260 +/- 28 fmol/mg protein) atria. The potency of adenosine to slow atrial rate and prolong AV nodal conduction time was greater in guinea pig than in rat or rabbit hearts. This rank order of potency correlated well with the number of binding sites for the specific adenosine receptor radioligand 125I-aminobenzyladenosine in guinea pig (102 +/- 13 fmol/mg protein), rat (11 +/- 0.5 fmol/mg protein), and rabbit (8 +/- 1 fmol/mg protein) atrial membranes. Hypoxia increased the rate of adenosine release by severalfold and caused slowing of heart rate and AV block. In spontaneously beating hearts, the main effect of hypoxia was a slowing of ventricular rate, which in the guinea pig heart was due to AV block and in the rat heart to atrial slowing. In atrial paced hearts, hypoxia caused a marked prolongation of AV nodal conduction time in guinea pig (39 +/- 4 msec) and rabbit (29 +/- 5 msec) hearts, but only small effect in rat hearts (10 +/- 2 msec). The differences in response to hypoxia could be accounted for by the species-dependent differences in the 1) amount of adenosine released and metabolized, 2) sensitivity of the hearts to adenosine, and 3) dependency of AV nodal conduction on atrial rate. The findings indicate that the results from physiological or pharmacological studies on adenosine in one species may not be applicable to others, and the ultimate effect of adenosine and hypoxia is to slow ventricular rate.
Critical review of gangliosides and thyrotropin-releasing hormone in peripheral neuromuscular diseases. The lack of effective therapy for many of the chronic neuromuscular diseases such as amyotrophic lateral sclerosis, hereditary motor sensory neuropathy (Charcot-Marie-Tooth disease), spinocerebellar degenerations and idiopathic polyneuropathy has led to a search for substances that may stimulate peripheral nerve regeneration. Two such agents that have been proposed are gangliosides (mixed purified bovine brain gangliosides, Cronassial) and thyrotropin releasing factor (TRH). Studies on both of these agents were initially reported with enthusiasm to be successful, but later double-blind controlled studies have failed to confirm these findings. This review provides critical analysis of the designs of studies of potentially effective agents in chronic neuromuscular diseases, and emphasizes the power of the placebo response, and the importance of designing placebos which are indistinguishable from the trial medication other than in the active effect.
Is routine preoperative hemodynamic evaluation of nonagenarians necessary? An Incidence of co-morbid cardiac disease in the elderly surgical patient as high as 66% has been previously reported. Even in the absence of clinically significant cardiac disease, advanced age alone is often considered sufficient indication for Swan-Ganz placement, hemodynamic evaluation, adjustment of fluid states, and inotropic support. Yet data clearly documenting the need for this evaluation and therapy are difficult to obtain. All major general surgical and orthopedic operations in non-agenarians were reviewed in our institution from July 1, 1987 through December 31, 1988. Fifty-one procedures were performed on 46 patients. None of these patients had preoperative Swan-Ganz catheterization or hemodynamic evaluation. Eighteen general surgical, 30 orthopedic, 2 neurosurgical, and 1 gynecological procedures were performed. Forty-three were performed under general anesthesia, 7 under spinal anesthesia, and 1 with local anesthesia. Seven out of 51 patients (14%) experienced major complications, and 16 out of 51 (31%) experienced minor complications. Thirty-day mortality was 0%, and 6-month survival was 92%. Only one complication occurred within 48 hours of surgery that might possibly have been prevented with hemodynamic evaluation, adjustment of fluid status, inotropic support, and intensive care unit monitoring.
Prospective study of a prosthetic H-graft portacaval shunt. This study was undertaken to prospectively evaluate the 8-mm Gore-Tex interposition H-graft portacaval shunt. Thirty-six high-risk patients at the University of South Florida-affiliated hospitals received small-diameter shunts because of bleeding esophagogastric varices over a recent 2-year period. Portal vein and portal vein-inferior vena cava gradients were significantly reduced after shunting. These pressure changes were manifested clinically by the absence of variceal rebleeding and improvement of ascites; in addition, the incidence of encephalopathy was low. The 8-mm graft maintained hepatopedal flow in 67% of the patients, but reversal of flow did not result in complications commonly associated with poor portal perfusion. Graft thrombosis occurred in four (11%) patients. All grafts were successfully revised, three by operative revision and one by an interventional radiologist. Operative mortality was low (11%), and morbidity was unusual. The small-diameter H-graft portacaval shunt is a safe and effective method of treatment for bleeding esophagogastric varices.
Unusual lymphoproliferative oropharyngeal lesions in heart and heart-lung transplant recipients. Three unusual cases of oropharyngeal lympho-proliferative lesions were seen in recipients of heart and heart-lung transplants. Two caused acute upper respiratory obstruction necessitating urgent ENT intervention. All patients were receiving immunosuppressive drugs including cyclosporin. The two obstructive cases were adenotonsillar enlargement in a 6-year-old, and a tumour of the tonsil and tongue base with cervical lymph node enlargement in a 32-year-old male. Both were caused by Epstein-Barr Virus-associated lymphoproliferative disorder. The third patient, a 32-year-old female, had a presumed low grade T-cell lymphoma that regressed spontaneously. Histopathological diagnosis of these lympho-proliferative disorders after transplantation usually requires immunocytochemistry to distinguish polyclonal proliferative disorders from true lymphoma. Polyclonal lymphoproliferative disorders after transplantation do not usually require aggressive cytoreductive therapy, but respond to simple measures such as the reduction of immunosuppression.
Peripheral arterial occlusive disease: prospective comparison of MR angiography and color duplex US with conventional angiography. Conventional angiography, two-dimensional inflow magnetic resonance (MR) angiography, and color duplex ultrasound (US) were performed on 12 patients in a blinded, prospective study. The ability to grade arterial lesions and plan revascularization interventions were compared. Arterial lesions were categorized as nonsignificant (0%-49% diameter reduction) or significant (50%-100% diameter reduction). Determination of nonsignificant and significant lesions with MR angiography was in agreement with that at conventional angiography in 100 of 140 lesions (71%). Agreement between results of conventional angiography and color duplex US occurred with 114 of 123 infrainguinal lesions (93%). Twenty-one vascular interventions were planned by using conventional angiography; there was agreement with color duplex US in 11 cases and MR angiography in five. Color duplex US performed well in the assessment of infrainguinal disease but was limited in the evaluation of iliac segments because of nonvisualization. The iliac region was visualized in more patients with MR angiography than with color duplex US, but image quality with MR angiography was inconsistent. Strategies to improve MR angiography of the peripheral vasculature merit further study.
Preventing postoperative acute bleeding of the upper part of the gastrointestinal tract. Two hundred and ninety-eight critically ill patients at risk for the development of postoperative stress ulcers and bleeding were randomized into three groups. The first group comprised 85 patients who received meciadanol, a new bioflavonoid, 500 milligrams every six hours through a nasograstric tube; the second group comprised 100 patients who received sucralfate (crushed tablets), 1,000 milligrams every six hours through a nasogastric tube, and the third group comprised 113 patients who received an antacid (Maalox [magnesium aluminum hydroxide gel]) through a nasogastric tube at an initial dose of 15 milliliters every hour. The gastric pH was measured hourly and titrated to a pH greater than or equal to 4.0 in patients in the group receiving the antacid. The gastric pH was measured every two hours in the other two groups. Bleeding in the upper part of the gastrointestinal tract was determined visually (frank blood in gastric contents) or by guaiac testing. Bleeding occurred in seven patients receiving meciadanol, nine receiving sucralfate and six receiving the antacid. The difference in rates of bleeding was not statistically significant. Correlation between the severity of illness index and the development of bleeding was poor, at least in the low and intermediate index range. In contrast, there was a strong correlation between the age of the patient and the development of bleeding. Only one patient younger than 50 years had bleeding develop. Apparently, meciadanol exerts its action by a mechanism other than pH control. It may, therefore, fill an important gap in the ability to prevent postoperative stress ulcers and bleeding.
Residual atrial septal perforation after percutaneous transvenous mitral commissurotomy with Inoue balloon catheter. To estimate the incidence of residual atrial septal perforation (ASP) following percutaneous transvenous mitral commissurotomy (PTMC) with the Inoue balloon catheter and to examine the factors contributing to ASP, we studied 46 patients with mitral stenosis undergoing PTMC. Residual ASP was evaluated by Doppler color flow imaging 1 day after PTMC, and was detected in 7 out of 46 patients (15.2%). We examined the relationship between the development of ASP (ASP+) and the age of the patient, the left atrial dimension before PTMC, the mean pressure difference between left and right atrium after PTMC, and the duration of the procedure from atrial septal puncture by the Brockenbrough method to balloon inflation. There was a good correlation between the development of residual ASP and the duration of the procedure (ASP+, 51.0 +/- 34.0 minutes; without ASP, 24.6 +/- 16.2 minutes; p less than 0.01). However, there was no significant correlation between the development of ASP and other factors. In the follow-up study, ASP disappeared in four patients within 3 months. ASP persisted in two patients for 1 year after PTMC. However, the shunt in these two patients was clinically insignificant. These data suggest that residual ASP may depend on the duration of the procedure, and that most cases of ASP disappear within 1 year after PTMC.
Childhood traumas: an outline and overview Childhood psychic trauma appears to be a crucial etiological factor in the development of a number of serious disorders both in childhood and in adulthood. Like childhood rheumatic fever, psychic trauma sets a number of different problems into motion, any of which may lead to a definable mental condition. The author suggests four characteristics related to childhood trauma that appear to last for long periods of life, no matter what diagnosis the patient eventually receives. These are visualized or otherwise repeatedly perceived memories of the traumatic event, repetitive behaviors, trauma-specific fears, and changed attitudes about people, life, and the future. She divides childhood trauma into two basic types and defines the findings that can be used to characterize each of these types. Type I trauma includes full, detailed memories, "omens," and misperceptions. Type II trauma includes denial and numbing, self-hypnosis and dissociation, and rage. Crossover conditions often occur after sudden, shocking deaths or accidents that leave children handicapped. In these instances, characteristics of both type I and type II childhood traumas exist side by side. There may be considerable sadness. Each finding of childhood trauma discussed by the author is illustrated with one or two case examples.
Outcome of CPR in a large metropolitan area--where are the survivors? STUDY OBJECTIVES: Survival from out-of-hospital cardiac arrest in cities with populations of more than 1 million has not been studied adequately. This study was undertaken to determine the overall survival rate for Chicago and the effect of previously reported variables on survival, and to compare the observed survival rates with those previously reported. DESIGN: Consecutive prehospital arrest patients were studied prospectively during 1987. SETTING: The study area was the city of Chicago, which has more than 3 million inhabitants in 228 square miles. The emergency medical services system, with 55 around-the-clock ambulances and 550 paramedics, is single-tiered and responds to more than 200,000 emergencies per year. TYPE OF PARTICIPANTS: We studied 3,221 victims of out-of-hospital cardiac arrest on whom paramedics attempted resuscitation. MEASUREMENTS AND MAIN RESULTS: Ninety-one percent of patients were pronounced dead in emergency departments, 7% died in hospitals, and 2% survived to hospital discharge. Survival was significantly greater with bystander-witnessed arrest, bystander-initiated CPR, paramedic-witnessed arrest, initial rhythm of ventricular fibrillation, and shorter treatment intervals. CONCLUSIONS: The overall survival rates were significantly lower than those reported in most previous studies, all based on smaller communities; they were consistent with the rates reported in the one comparable study of a large city. The single factor that most likely contributed to the poor overall survival was the relatively long interval between collapse and defibrillation. Logistical, demographic, and other special characteristics of large cities may have affected the rates. To improve treatment of cardiac arrest in large cities and maximize the use of community resources, we recommend further study of comparable metropolitan areas using standardized terms and methodology. Detailed analysis of each component of the emergency medical services systems will aid in making improvements to maximize survival of out-of-hospital cardiac arrest.
Syndromes of transient amnesia: towards a classification. A study of 153 cases. Of 153 patients presenting with acute transient amnesia, 114 fulfilled the proposed strict diagnostic criteria for transient global amnesia (TGA). The prognosis of this group was excellent with the exception of a small subgroup (7%), largely identifiable because of atypically brief or recurrent attacks, who developed epilepsy of temporal lobe type on follow up. Computerised tomography (CT) scans performed on 95 patients were normal, evidence for covert alcoholism was lacking and there was a familial incidence of approximately 2%. By contrast, the group of 39 patients who did not meet the criteria for TGA had a significantly worse prognosis with a high incidence of major vascular events. The groups could not be distinguished on the basis of behavioural characteristics during the attack. The following classification was proposed: 1) pure TGA--attacks fulfilling the strict criteria, and of more than one hour in duration which do not require detailed investigation, 2) probable epileptic amnesia--attacks of less than an hour or rapidly recurrent, 3) probable transient ischaemic amnesia, a minority of cases with additional focal neurological deficits during the attack.
A comparison in vitro of human and rabbit distal colonic muscle responses to inflammatory mediators. The present study compared in vitro the motor responses of human and rabbit distal colonic longitudinal and circular muscle to acetylcholine, histamine, leukotrienes B4 and D4, and prostaglandins E2 and F2 alpha. The active and passive mechanical properties of these muscles were also evaluated. All muscle types were contracted by acetylcholine and histamine. Longitudinal muscle from both species was contracted by prostaglandin E2 and prostaglandin F2 alpha, although rabbit muscle was more sensitive. Prostaglandin E2 relaxed the majority of both human and rabbit circular muscle preparations that were studied. Prostaglandin F2 alpha first relaxed and then contracted circular muscle from both species. Leukotriene B4 had no effect on any tissue studied. Leukotriene D4 caused transient relaxations in a proportion of all muscle types, but the relaxations were not concentration-related. Contractile responses did not differ under isotonic recording conditions, but relaxations were much more clearly defined. Based on experiments using atropine, phentolamine and propranolol, and pyrilamine or tetrodotoxin, it was concluded that the responses of both human and rabbit distal colonic muscles to these inflammatory mediators have a similar pharmacological basis. All muscle types exhibited low passive tension and developed active tension in the range 0.8-1.2 Lo. These data strongly support the belief that after the onset of an induced colitis, the rabbit colon has value as a predictive model for the study of inflammatory mediator-induced colonic motility changes in humans.
Early cerebral infarction: gadopentetate dimeglumine enhancement Gadopentetate dimeglumine was administered prospectively to 50 patients who presented for magnetic resonance (MR) imaging within 2 weeks after a cortical cerebral infarction. Twenty-two patients (44%) were imaged within 3 days after clinical ictus. Abnormalities detected with gadopentetate dimeglumine enhancement were observed in 46 (92%) of 50 patients. Classic parenchymal enhancement was a late finding, observed in all patients (17 of 17) imaged at 7-14 days after infarction. Before this time, three additional phases of contrast material-related abnormalities were observed. Enhancement of vessels supplying the infarct ("intravascular enhancement sign") was the earliest finding, seen in 17 (77%) of 22 infarcts aged 1-3 days. From day 2 to day 6, abnormal enhancement of meninges adjacent to the infarct was frequently noted ("meningeal enhancement sign"). Finally, a transition phase that combined intravascular or meningeal enhancement with early parenchymal enhancement was seen from day 3 to day 6. Gadopentetate dimeglumine-enhanced MR imaging in early stroke reveals evidence of vascular engorgement and sluggish flow, which precede the development of classic parenchymal enhancement.