123rc/medical_text huggingface dataset:
Injury biomechanics of the human cervical column. In this study, the authors have developed a technique to replicate clinically relevant traumatic cervical spine injuries and determined the injury biomechanics. Because of the importance of compressive forces in neck injuries, this research was conducted using compression as the primary load vector. Six fresh human cadaveric head-neck complexes were prepared by fixing the distal end in methylmethacrylate. Tests were done with varying loading rates to include quasistatic and dynamic conditions. For quasistatic experiments, the proximal end was fixed to the piston of the testing device. In dynamic tests, the cranium was unconstrained, and to maintain stability, the effects of the spinal musculature were simulated by means of pulleys, deadweights, and springs in the anterior and posterior parts of the head-neck complex. Quasistatic tests conducted at a rate of 2.0 mm/sec produced cervical spine trauma at forces ranging from 1.7 to 2.3 kN, with deformations ranging from 2.2 to 3.7 cm. The specimens were deep-frozen at the level of injury, preserving the local deformation of the tissues to enable a detailed evaluation immediately after the injury. Dynamic tests conducted at velocities of 3.2 to 5.7 m/sec resulted in impact injuries at one level of the head-neck complex. The applied forces at the vertex were considerably higher than those recorded at the distal end. The failure deformations for both the quasistatic (2.2-3.7 cm) and dynamic (1.7-3.2 cm) tests, however, were found to be similar, suggesting that the human head-neck complex is a deformation-sensitive structure.
Kawasaki-like syndrome after treatment with mesalazine. We report a patient who developed a severe hypersensitivity reaction, including rash, lymph node enlargement, fever, hepatitis, and eosinophilia, after sulphasalazine therapy. Five years later, he developed a similar reaction after exposure to mesalazine, the salicylic compound of sulphasalazine. We conclude that patients with known severe systemic reaction to sulphasalazine therapy are also at risk for such a reaction when treated with a 5-ASA preparation.
Epithelial dysfunction in nonbacterial cystitis (interstitial cystitis). Traditional concepts of impermeability of the bladder have centered around unique cellular tight junctions and ion pumps. However, recent data from our laboratory have shown that the bladder epithelium in animals and humans relies primarily on its surface glycosaminoglycans to maintain its impermeability. This study demonstrates the first disease associated with an epithelial dysfunction of the bladder, that is a leaky epithelium. The study consisted of 31 normal subjects and 56 individuals with interstitial cystitis. Interstitial cystitis patients were shown to have a leaky epithelium by placing a solution of concentrated urea into the bladder and measuring the absorption. The normal subjects absorbed 4.3% in 45 minutes, while the interstitial cystitis patients absorbed 25% (difference is highly significant, p less than 0.005). Interstitial cystitis patients with Hunner's ulcers (10) had a 34.5% absorption rate, while those without ulcers absorbed 22.8% (46). This difference also was highly significant (p = 0.002) and supports the concept that patients with ulcers have clinically worse disease.
Iatrogenic saphenous neuralgia: successful therapy with neuroma resection. We report the case of a patient with saphenous neuralgia secondary to iatrogenic trauma resulting from bypass surgery in the femoral-popliteal region. Early symptoms of this condition were medial calf and ankle pain, with no findings of motor and reflex abnormalities. Exploration of the thigh 2 years later revealed a neuroma of the nerve in the distal dissection site, medial to the knee. Resection of the neuroma alleviated this condition. It is noted that saphenous neuropathy is seen as a spontaneous entrapment syndrome as well as a complication of orthopedic and vascular procedures performed on the medial area of the knee. Saphenous neuralgia is often not recognized by neurosurgeons. If the condition is intractable, it does respond to surgical therapy.
Prognostic significance of proteinuria one year after onset of diarrhea-associated hemolytic-uremic syndrome. We examined the prognostic value of changes in the amount of proteinuria, measured as protein/creatinine ratios in early-morning urine samples, in 40 children who had had diarrhea-associated hemolytic-uremic syndrome. One year after diagnosis, 87% of those who seemed to have fully recovered had normal urinary protein/creatinine ratios, compared with none of those with poor outcomes (p less than 0.001). None of those with poor outcomes achieved normal protein/creatinine ratios during follow-up to a maximum of 5 1/2 years, but 93% of those who made a full clinical recovery no longer had proteinuria. Measurement of the protein/creatinine ratio in an early-morning sample of urine is a simple, cost-effective, and noninvasive means of monitoring the progress of patients with diarrhea-associated hemolytic-uremic syndrome, provided that a technique sensitive at low protein concentrations is employed.
Efficacy of propafenone in preventing ventricular tachycardia: inverse correlation with rate-related prolongation of conduction time The efficacy of propafenone in preventing induction of ventricular tachycardia was evaluated in 25 consecutive patients (mean age 62 +/- 8 years) with remote myocardial infarction who underwent programmed electrical stimulation for ventricular arrhythmia using up to three extra-stimuli after basic drive at the right ventricular apex. In nine patients (Group A), propafenone prevented induction of sustained ventricular tachycardia (noninducible in four, nonsustained [less than 30 s] in five). In the other 16 patients (Group B), sustained ventricular tachycardia was still inducible; in 11 of the 16, the tachycardia configuration was unchanged but the cycle length was significantly longer (431 +/- 99 versus 284 +/- 44 ms, p less than 0.001). Propafenone did not significantly affect either sinus cycle length or AH and HV intervals. However, it prolonged QRS duration during sinus rhythm equally in both groups of patients. With ventricular pacing, propafenone also prolonged right ventricular effective and functional refractory periods and surface QRS duration. There was greater lengthening of the paced surface QRS duration when drug therapy was ineffective (for example, +35 +/- 12 ms in Group A versus +69 +/- 23 ms in Group B at a basic drive of 400 ms, p less than 0.01). Drug-induced prolongation of a paced QRS complex greater than 40 ms had a 94% positive predictive value for drug failure to prevent induction of ventricular tachycardia. Drug-induced percent prolongation of ventricular tachycardia cycle length in Group B did not correlate well with percent QRS prolongation.
Pseudopsammomatous meningioma with elevated serum carcinoembryonic antigen: a true secretory meningioma. Case report. A sphenoid-wing meningioma in a 60-year-old woman was accompanied by elevated serum carcinoembryonic antigen (CEA) levels, which returned to normal after removal of the tumor. Light microscopic examination revealed a secretory meningioma containing numerous pseudopsammoma bodies and a prominent vascular pattern. Immunohistochemical analysis showed the tumor cells and pseudopsammoma bodies to be CEA-positive. This case illustrates the possibility that secretory meningioma may be associated with clinically detectable secretion of CEA. The report also documents the rare occurrence of elevated serum CEA in a primary benign intracranial tumor.
Complications of Tenckhoff catheters post removal. Complications due to Tenckhoff catheters can occur at prolonged intervals after their removal. From January 1979 to October 1989, 431 patients at our center began continuous ambulatory peritoneal dialysis (CAPD), 278 of whom subsequently transferred to another form of renal replacement therapy. We identified 12 patients (4.3% or 12/278) with post removal catheter complications. There were 14 post removal complications, two each in two patients, and one in each of 12 others. The mean time to complication was 541 +/- 143 days (27-2,040). In 71% (10/14) of the complications, an abscess was found at the site of the previously removed Tenckhoff catheter. In 29% (4/14) of the complications, foreign body material consistent with a retained cuff was recovered. Documentation at the time of Tenckhoff catheter removal should include a statement regarding the presence of the Tenckhoff catheter cuffs, and patients with retained cuffs should be monitored closely for the development of abscesses or other complications. Immunocompromised patients are at high risk for these complications.
Peripheral alpha-1 and alpha-2 adrenergic receptors in three models of hypertension in rats: an in vitro autoradiography study. In vitro autoradiography was used to compare peripheral alpha-1 and alpha-2 adrenergic receptor binding in various tissues using [3H]prazosin and [3H]rauwolscine, respectively, in three models of experimental hypertension in rats. Models studied included two-kidney, one-clip hypertension, one-kidney, one-clip hypertension, desoxycorticosterone-salt hypertension, and three normotensive control groups: two-kidney control, one-kidney control and salt-loaded control. Blood pressures at death were significantly higher in all three hypertensive groups compared with normotensive controls, but there were no significant differences among the hypertensive or normotensive groups. Plasma norepinephrine levels were significantly elevated in all three hypertensive groups compared with respective controls, with no significant differences among hypertensive or control groups. In all three hypertensive groups, there were significant reductions in binding of aortic and mesenteric vascular alpha-1 receptors, renal tubular alpha-1 and alpha-2 receptors, and adrenal cortical alpha-2 receptors when compared with respective control groups. Reduced binding of cardiac ventricular alpha-1 and alpha-2 receptors was also found in all hypertensive groups, but not to statistically significant levels. No significant differences in intestinal alpha-1 and alpha-2 receptor binding were detected in either hypertensive or normotensive groups. The results suggest increased peripheral sympathetic activity in all three models of experimental hypertension, which is associated with down-regulation of alpha-1 and alpha-2 receptors in a number of peripheral tissues, especially those that control cardiovascular hemodynamics and fluid and salt balance. There is no evidence of an increase in peripheral alpha receptor binding as has often been found in some models of genetic or spontaneous hypertension.
Estimating left ventricular filling pressure during positive end-expiratory pressure in humans. In the critically ill, accurate measurements of left ventricular (LV) filling pressure using pulmonary artery occlusion pressure (Ppao) are important for diagnostic and therapeutic purposes. In patients receiving positive end-expiratory pressure (PEEP), Ppao may not reflect LV filling pressure because of elevated pericardial pressure (Ppc). It has been proposed that in humans, Ppc and right atrial pressure (PRA) are equal, so that referencing Ppao to PRA may improve the assessment of LV filling pressure when Ppc is elevated. Similarly, it has also been shown in the dog that nadir Ppao immediately after airway disconnection from PEEP (nadir Ppao), accurately reflects LV filling pressure when LV filling pressure is greater than or equal to 10 mm Hg. We examined methods of estimating LV filling pressure using Ppao measurements under conditions in which increases in Ppc were the primary determinants of differences in the two measurements. Using left atrial pressure (PLA) relative to Ppc, called transmural PLA (PLAtm), as LV filling pressure, we compared the accuracy of Ppao, nadir Ppao, and Ppao relative to PRA to reflect PLAtm in 15 postoperative cardiac surgery patients in whom an air-filled pericardial balloon catheter and a left atrial catheter were inserted during surgery. PEEP was sequentially increased from zero to 15 cm H2O. We found that PRA always exceeded Ppc (p less than 0.01) and increased less with PEEP than did Ppc (p less than 0.05). At less than or equal to 5 cm H2O PEEP, both Ppao and nadir Ppao were similar to each other and to PLAtm.
Quinapril in chronic heart failure. Angiotensin converting enzyme inhibitors are now firmly established in the treatment of patients with chronic heart failure (CHF). Their beneficial acute and chronic hemodynamic effects are not associated with reflex tachycardia or drug tolerance. Angiotensin converting enzyme inhibitors produce symptomatic improvement and improve exercise capacity in all grades of heart failure. They also improve the prognosis of patients with severe heart failure. Quinapril is a recently introduced, nonsulfhydryl ACE inhibitor, whose intermediate half-life makes it well-suited for the treatment of patients with CHF. The acute and chronic hemodynamic effects of quinapril are similar to those of other ACE inhibitors. In a large, multicenter, randomized, placebo-controlled study of 225 patients with mild to moderate CHF, 10 to 40 mg/day quinapril significantly improved clinical status and exercise capacity in a dose-related manner. The incidence of side effects did not differ significantly from that of placebo. The initial studies with quinapril are promising and warrant further clinical investigation of this compound.
Increased MEPP frequency as an early sign of experimental immune-mediated motoneuron disease. Intracellular recordings of miniature end-plate potentials were performed in extensor digitorum longus muscles from guinea pigs with experimental immune-mediated motoneuron destruction. In the early stages of the disease, the miniature end-plate potential frequency was elevated compared to that in control and normal animals. The amplitude and time course of the miniature end-plate potentials as well as the resting potential of the muscle fibers were not altered, which implies integrity of the postjunctional membrane. The increase in frequency of miniature end-plate potential reflects an increase of basal acetylcholine release and documents dysfunction of the presynaptic terminal of the neuromuscular junction. The increased frequency was associated with high levels of antimotoneuronal IgG in the blood and the presence of IgG at motor end-plates. These data suggest that the presynaptic terminal of the neuromuscular junction may be involved in the immune attack in animal models of motoneuron degeneration.
Refeeding of infants with acute diarrheal disease. The purpose of this study was to determine which infant formula among five would be the most efficacious for the refeeding of infants during an acute episode of diarrhea. Fifty male infants less than 12 months of age with severe diarrhea and at least 5% dehydration were admitted to a metabolic unit and studied in a prospective, single-blind protocol. Ten infants randomly received one of five types of formula: two-thirds diluted cow milk, cow milk formula (Nanon, Nestle, Inc., Sao Paulo, Brazil), Portagen, Pregestimil, or Prosobee (Mead Johnson & Co. Division, Evansville, Ind.). They continued to receive the same formula for 72 hours unless dehydration occurred. There were no associated infections, and they received no prior antibiotic treatment. Oral hydration together with intravenous fluid therapy was given to all patients during the initial treatment. During the first 72 hours of refeeding, patients fed Portagen excreted the least amount of stool and required reduced quantities of intravenous fluids or oral hydration. In contrast, patients fed diluted cow milk or any other formula had more severe diarrhea. Nine of the 10 patients fed Portagen completed the 72-hour treatment, whereas only 2 of 10 fed diluted cow milk tolerated it. Similarly, the cumulative proportions for high purging rate, dehydration, carbohydrate intolerance, and vomiting were more favorable for Portagen and least acceptable for diluted cow milk. No differences were found among the remaining three formulas tested. These data show that diluted cow milk is poorly tolerated by infants with severe diarrhea, whereas Portagen is more effective.
Olfactory neuroblastoma: clinicopathologic and immunohistochemical characterization of four representative cases. Olfactory neuroblastomas are rare tumors whose clinical prognosis is not predictable by assessment of initial stage or grade. The pathologic diagnosis is often difficult because of the wide range of the patient's age and histologies. In this report, we document that the diagnosis of olfactory neuroblastoma can be clarified by immunohistochemical demonstration of a unique antigenic profile that can be obtained in routinely processed biopsies. We describe four cases of olfactory neuroblastoma diagnosed and treated from 1979 to 1989, each confirmed by immunohistology. One of our patients was misdiagnosed twice at an outside institution, first as having nasopharyngeal carcinoma and then as having small-cell, undifferentiated "oat cell" carcinoma. Despite accurate tumor diagnosis and appropriate therapy, we found that there was no apparent correlation of clinical outcome with Kadish clinical stage or histologic grade of tumor.
An intracranial mass lesion in systemic xanthogranulomatosis: case report. The authors describe a 42-year-old woman with systemic xanthogranulomatosis and bilateral intraorbital tumors, who subsequently developed multiple lesions of the intracranial dura mater, spinal cord, retroperitoneum, pericardium, and mediastinum. Systemic xanthogranulomatosis is histologically similar to systemic Weber-Christian disease, except for the absence of subcutaneous panniculitis. Immunohistochemical studies suggest that this clinical entity can be differentiated from histiocytosis X, because foamy cells in systemic xanthogranulomatosis demonstrate macrophages but not T-zone histiocyte markers. Differentiation of this disease from other intracranial xanthogranulomas and treatment are discussed.
Epidural morphine for analgesia after caesarean section: a report of 4880 patients This retrospective study was undertaken to assess the efficacy and safety of epidural morphine in providing analgesia following Caesarean section under epidural anaesthesia. The morphine was administered as a single bolus, following delivery, in doses ranging from 2 to 5 mg. The charts of 4880 Caesarean sections, performed on 4500 patients, were reviewed. The duration of analgesia and the occurrence of any symptoms which might be side-effects of the epidural morphine were recorded. The duration of analgesia was 22.9 +/- 10.1 hr and was not correlated with the dose of epidural morphine. Eleven per cent of the patients required no supplemental analgesia during the first 48 hr. Twelve patients (0.25 per cent) had respiratory rates less than 10 breaths per minute, on at least one occasion. No serious sequelae resulted from these periods of bradypnoea. Pruritus occurred in 58 per cent of patients, nausea and vomiting in 39.9 per cent and dizziness in ten per cent. Herpes simplex labialis was recorded in 3.5 per cent of patients. Epidural morphine is thus confirmed as an effective analgesic technique post-Caesarean section with 3 mg being the optimal dose. Even in this young healthy patient population, clinically detectable respiratory depression occurs so clinical respiratory monitoring is indicated.
Endothelin family in human plasma and cerebrospinal fluid. To clarify whether endothelin may be present in human cerebrospinal fluid (CSF) and, if it exists, to compare its molecular forms with those of endothelin in human plasma, we analyzed pooled human CSF and plasma by high performance liquid chromatography with specific enzyme immunoassays for each endothelin peptide. Of the four human endothelin peptides hitherto identified, big endothelin-1 was the major molecular form of endothelin present in human CSF. In addition, there was a small but significant amount of endothelin-1 and endothelin-3 in CSF, while endothelin-2 was not detectable. Similarly, big endothelin-1, endothelin-1, and endothelin-3 were identified in human plasma. Although big endothelin-1 was the most abundant, a substantial amount of endothelin-1 and endothelin-3 was found in plasma with a resultant lower molar ratio of big endothelin-1 to endothelin-1 than in CSF. In all CSF samples from 17 patients requiring diagnostic lumbar puncture or lumbar anesthesia, endothelin was detectable, with a preponderance of big endothelin-1 relative to endothelin-1 and endothelin-3. The mean concentrations of endothelin-1 and endothelin-3 in simultaneously collected plasma were significantly (P less than 0.01) higher than those in CSF, while there was no significant difference between the mean big endothelin-1 concentration in plasma and that in CSF. There was no significant correlation among concentrations of big endothelin-1, endothelin-1, and endothelin-3 in each paired sample. These results indicate that endothelin is present in human CSF that is differently processed from endothelin in vascular endothelial cells and suggest a possible role for endothelin as a modulator of neuronal functions.
Clinical trials. Access and reimbursement. Clinical trials continue to play an extremely important role in clinical oncology, but of the nearly 1 million cancer patients diagnosed in the United States each year, only 2.5% (25,000) participate in such trials. Access to clinical trials has been enhanced by the adoption by the NCI of a promotional campaign that involves seminars, dissemination of information to national and local news media, and assisting in making information about clinical trials available to patients and physicians. Factors that hinder accrual of patients to clinical trials include: (1) physicians' concern about losing contact with patients, (2) physicians who feel that "experimental therapy" is not as good as "standard therapy," and (3) the time it takes to discuss and implement clinical trials. Reimbursement for clinical trials has also become a major concern. Who should pay for clinical research? Many insurance companies have been reluctant to pay for "experimental therapy" but will pay for "standard therapy." If this trend continues, the whole concept and organization of clinical trials, i.e., Phase I, II, and III trials, will be greatly hindered. Solutions must be found, and third party payers need to realize that an investment in clinical trials today will decrease the long term costs of state-of-the-art care.
Standards for analysis of ventricular late potentials using high-resolution or signal-averaged electrocardiography. A statement by a Task Force Committee of the European Society of Cardiology, the American Heart Association, and the American College of Cardiology. Sufficient data are available to recommend the use of the high-resolution or signal-averaged electrocardiogram in patients recovering from myocardial infarction without bundle branch block to help determine their risk for developing sustained ventricular tachyarrhythmias. However, no data are available about the extent to which pharmacological or nonpharmacological interventions in patients with late potentials have an impact on the incidence of sudden cardiac death. Therefore, controlled, prospective studies are required before this issue can be resolved. As refinements in techniques evolve, it is anticipated that the clinical value of high-resolution or signal-averaged electrocardiography will continue to increase.