123rc/medical_text huggingface dataset:
Cholinergic stimulation of the pons depresses respiration in decerebrate cats. The injection of carbachol into the pontine tegmentum of decerebrate cats evokes a postural motor atonia that has many of the characteristics of the atonia of natural rapid-eye-movement (REM) sleep (Morales et al. J. Neurophysiol. 57: 1118-1129, 1987). We have used the carbachol-injected decerebrate cat to study the changes in respiratory neuronal activity that accompany the atonia. The activities of representative respiratory motor nerves--phrenic, intercostal, and hypoglossal--and that of a motor branch of C4 were recorded in decerebrate, vagotomized, paralyzed, and artificially ventilated cats. After the microinjection of carbachol, there was a profound suppression of activity in all the nerves and a decrease in respiratory rate. This was a consistent stereotyped response in which the magnitude of the suppression of respiratory-related activity was phrenic (to approximately 65% of control) less than inspiratory intercostal (approximately 50%) less than hypoglossal (approximately 10%) less than expiratory intercostal (approximately 5%). The decrease in respiratory rate (to approximately 70% of control) was caused by a prolongation of both inspiratory and expiratory durations. Complete reversal of the carbachol effect was elicited by the microinjection of atropine into the same site as the carbachol injection. This allowed us to produce a second episode of atonia by the injection of carbachol into the contralateral pons. Thus we have demonstrated the existence of neural pathways originating in the cholinoceptive cells of the pons that have the potential to powerfully and differentially depress various respiratory motoneuronal pools and to reduce the respiratory rate. These pathways are likely to be activated along with the atonia of REM sleep.
Physical and psychosocial consequences of total laryngectomy. The incidence and severity of respiratory symptoms after total laryngectomy and their influence on daily living were studied in 59 laryngectomized patients. Daily sputum production was the principal complaint of these patients (98%), followed by coughing (64%) and the need for frequent forced expectoration (more than 5 times a day) in order to clear the airway (57%). Frequent stoma cleaning (more than 5 times a day) was required by 37% of the patients. Significant correlation was found between respiratory symptoms, voice rehabilitation and several aspects of daily living, including fatigue, sleep problems, social contacts and psychological distress. These findings indicate that respiratory symptoms after total laryngectomy are both frequent and troublesome. The development of effective methods for minimizing and/or preventing such respiratory problems would contribute significantly to improving the quality of life of laryngectomized patients.
Significance of blasts in low-cell-count cerebrospinal fluid specimens from children with acute lymphoblastic leukemia. The purpose of this study was to determine whether the presence of more than 5% blasts in a differential count of cytocentrifuged cerebrospinal fluid (CSF) with less than 6 leukocytes/microliter was predictive of central nervous system (CNS) relapse in children with acute lymphoblastic leukemia (ALL). A double concentrate method of cytocentrifuge preparation was used to analyze 4543 consecutive CSF specimens from 349 children with ALL between January 1, 1982, and September 30, 1988. One hundred nine CSF specimens from 58 evaluable children had less than 6 leukocytes/microliter and more than 5% blasts on cytocentrifuge differential count (low-cell-count specimen with blasts [LCB]). During the study period, 25 of 332 evaluable children (7.5%) had CNS leukemic recurrence. In 22 of 25 (88%), the CNS relapse was preceded by at least one abnormal low-cell-count CSF specimen. One of 34 patients with a single LCB at diagnosis (3%) had subsequent CNS relapse compared with five of eight patients (62.5%) with a single LCB during remission (P = 0.0002). Of 16 children with two or more LCB during remission, nine (56%) had CNS relapse defined by standard criteria, whereas six additional patients in this group were declared to be in CNS relapse on the basis of their repetitive LCB. Whether diagnosing CNS recurrence earlier in its course based on a modification of the definition of CNS leukemia will change the frequency of subsequent adverse events or make possible decreased intensity of CNS retreatment remains to be determined.
Treatment of flexor tenosynovitis of the hand ('trigger finger') with corticosteroids. A prospective study of the response to local injection. We developed a protocol to maximize medical therapy for "trigger finger." Fifty-eight patients with 77 episodes of flexor tenosynovitis of the hand that was resistant to rest, therapy with nonsteroidal anti-inflammatory drugs, and/or splinting were treated with single or multiple injections of depo-methylprednisolone acetate or triamcinolone acetonide. Patients were prospectively followed up for an average of 4.6 years. Results showed that symptoms and signs resolved in 61% after a single injection. Recurrent episodes, after prolonged pain-free intervals, occurred in 27% and were effectively re-treated with injection. In 12% of cases, either injection failed or early recurrence required surgical release. Local adverse reactions to injection, including pain at the injection site, stiffness, ecchymosis, or atrophy of subcutaneous fat, were self-limited. No episodes of postinjection infection or tendon rupture occurred. The medical management of flexor tenosynovitis with local corticosteroid injection(s) is effective in nearly 90% of cases and is free from serious adverse reactions.
Microvascular right-to-left pulmonary shunt demonstrated by a radionuclide method. A 37-yr-old man with angiolymphoid hyperplasia (Kimura's syndrome), who had been treated unsuccessfully for suspected asthma, was investigated due to a decrease in arterial oxygen saturation (86%). Right heart catheterization and angiography of the pulmonary artery failed to demonstrate any right-to-left shunts. However, simultaneous scintigraphy over the lungs, kidneys, and head after injection of 150 MBq technetium-99m-labeled macroaggregated albumin i.v. and inhalation of 150 MBq krypton-81m demonstrated a right-to-left shunt in the lungs probably caused by precapillary pulmonary arteriovenous shunts.
Mandibular osteomyelitis in a patient with sickle cell anemia: report of case. A case is presented in which mandibular osteomyelitis and mental nerve paresthesia developed in a patient with sickle cell anemia. This infection appeared to precipitate a sickle cell crisis. The mechanisms for these patients' propensity to infection and the diagnosis and management of sickle cell osteomyelitis of the jaws are discussed.
Microvascular pedal bypass for salvage of the severely ischemic limb Bypass to the pedal arteries was performed with use of the operating microscope and standard microsurgical technique in 37 patients with severe, chronic ischemia of a lower extremity. Twenty-one patients (57%) had three or more cardiovascular risk factors, and 22 (59%) had diabetes. Preoperative arteriography identified a pedal artery suitable for bypass in all but one patient. The greater or lesser saphenous vein was used in all patients, most frequently as a nonreversed, translocated vein graft. An arm vein was used as part of a composite graft in only one patient. No early deaths occurred, and only one patient had a perioperative myocardial infarction. Although five grafts occluded within 30 days, four were successfully revised, and 36 patients had a patent graft at the time of dismissal from the hospital. At 1 year, the primary graft patency rate (patency without revision) was 60.8%, and the secondary patency rate was 68.8%. One early and six late amputations were performed; the cumulative 1-year limb salvage rate was 82.4%. Grafts with an intraoperative flow rate of 50 ml/min or more had a better patency rate than those with a lower flow rate. The presence of diabetes did not adversely affect long-term patency. Of the 34 patients who were alive at the time of this report, 27 (79%) had a functional foot that allowed ambulation, had no rest pain, and had no substantial loss of tissue. Pedal bypass should be considered for critical, chronic ischemia, even if the patient has an increased surgical risk and advanced distal atherosclerotic disease.
Functional character and augmentation of lymphocytes in regional lymph nodes of patients with lung cancer. It appears that lymph node metastases are more frequent in lung cancer than in other cancers because of impaired defensive mechanisms in the regional lymph nodes. However, little is known about the immunologic function of regional lymph node lymphocytes (RLNL) in patients with lung cancer. We have studied the immunologic properties of RLNL in comparison with peripheral blood lymphocytes (PBL). We measured the natural killer (NK) cell activity of RLNL and PBL in patients with lung cancer and found that the NK activity was significantly more depressed in the RLNL than in the PBL. In contrast, interleukin-2 (IL-2) production was markedly higher in the RLNL than in the PBL. The cytotoxic effect of RLNL in nonmetastatic lymph nodes on target cells (such as K562 cells) or PC-3 and PC-10 cells (NK-resistant, human lung cancer of adenocarcinoma and epidermoid carcinoma, respectively) was significantly enhanced by in vitro incubation with recombinant IL-2 (rIL-2). Furthermore, we clarified that both rIL-2 and OK-432, which is a biologic response modifier and IL-2 inducer as well, augmented the cytotoxicity of RLNL and that these effector cells were lymphokine-activated killer (LAK) cells. The depletion of lymphocyte subsets by pretreatment with specific monoclonal antibody showed that the LAK activity in RLNL was mediated by CD3+ and CD8+ cells, whereas the lymphocyte subsets contributing the LAK activity in PBL were CD3+ and CD16+ cells. It was concluded that a majority of the effector cells in RLNL were LAK cells of the cytotoxic T cell population.
Bleeding gastroesophageal varices: gastric vein embolization after partial portal decompression. Shunts that decompress the portal vein are effective in the treatment of bleeding esophageal varices. Use of large-caliber portacaval shunts, however, results in the complete decompression of the portal system and the risk of subsequent development of hepatic encephalopathy. Use of small-caliber portacaval shunts results in mild portal hypertension and less frequent hepatic encephalopathy but may increase the risk of recurrent bleeding. Thirty-three patients underwent angiography after partial decompression portacaval shunting (median trans-shunt pressures, 8 mm Hg). Embolization of residual varices, noted in 13 patients, was performed. Results included one complication with no sequelae and no bleeding a mean of 13 months after the procedure was performed. Trans-shunt embolization of esophageal varices effectively prevents bleeding varices after partial portal decompression.
The symptom sensitivity index: a valuable additional parameter in 24-hour esophageal pH recording. Twenty-four-hour esophageal pH monitoring is useful for the quantitative measurement of gastroesophageal reflux and for the demonstration of a temporal relationship between symptoms and reflux. The symptom index, a numerical score, was developed to quantify the association between symptoms and reflux. Because the symptom index primarily assesses the specificity of a patient's reflux symptoms, we propose to refer to this score as the symptom specificity index. Because of certain limitations of this score, we developed and evaluated a new score, the symptom sensitivity index, that quantifies the subject's sensitivity for reflux. Fifty-two consecutive patients, referred to our laboratory for ambulatory 24-h pH recording were studied. Beside the conventional reflux variables, both indexes were calculated. Although a statistically significant correlation between the indexes was found, discordance between the specificity and sensitivity indexes was seen in 17 patients (33%). Based on the findings in this study we advocate that the symptom sensitivity index should be used, in addition to the symptom specificity index, and incorporated in future pH studies to optimalize the interpretation of the results.
Early beneficial effect of streptokinase on left ventricular function in acute myocardial infarction. The effect of intravenous streptokinase therapy on the time course of functional recovery was investigated in a controlled study of 64 patients randomized within 3 hours after the onset of acute myocardial infarction (AMI). Contrast ventriculography was performed 1 to 4 days after AMI and repeated 5 weeks later. Wall motion was analyzed by the centerline method in the central infarct, peripheral infarct and noninfarct regions. In patients with ventriculographic data at the early catheterization, streptokinase-treated patients had less severe hypokinesia in the central infarct region than control patients (-2.9 +/- 0.9 [n = 29] vs -3.4 +/- 0.7 standard deviations below normal [n = 21], p less than 0.05). The benefit of streptokinase was more marked in the peripheral infarct region (-1.5 +/- 0.7 vs -2.1 +/- 0.6, p less than 0.001). As a result, the ejection fraction was slightly higher in treated versus control groups (46 +/- 10 vs 43 +/- 7%, respectively; difference not significant). At 5 weeks, function in the streptokinase and control groups had diverged further because of continued improvement in the streptokinase-treated patients. This study shows that streptokinase benefits left ventricular (LV) function by 1 to 4 days after AMI, earlier than previously reported. The benefit was not limited to the peripheral infarct region, where ischemia might have been less severe, but was also seen in the central infarct region. The implication is that thrombolytic therapy can improve LV function during the period of myocardial stunning, while myocardial function is still recovering.
Subscapular elastofibroma in a young pitcher. A case report. Subscapular elastofibromas and scapulothoracic bursitis can cause symptomatic masses in baseball pitchers. Both processes appear to represent reactive soft tissue responses to repetitive stress at the inferior border of the scapula. It is assumed that most masses in the subscapular area represent scapulothoracic bursitis rather than an elastofibroma. However, it is possible that some of the masses treated conservatively as scapulothoracic bursitis may be elastofibromas. A study is currently under way to evaluate the incidence of subscapular masses in college and professional pitchers in the United States. A follow-up report is anticipated when the study has been completed. The author requests information concerning any confirmed cases of elastofibroma in baseball pitchers.
Ataxia and peripheral neuropathy: a benign variant of peroxisome dysgenesis. A 5-year-old boy with panperoxisomal dysfunction is described. Clinical features included hypotonia, areflexia, and ataxia. Cognition, vision, hearing, and hepatic function were normal. A panel of peroxisomal markers, including very-long-chain fatty acids, phytanic acid, pipecolic acid, and catalase compartmentalization, were abnormal. This is a uniquely benign syndrome of disordered peroxisome biogenesis.
Resection and reconstruction for soft-tissue sarcomas of the extremity. Soft-tissue sarcomas are uncommon malignant tumors, and when a diagnosis is made early, the patient has up to an 80% chance of surviving. In treating soft-tissue sarcomas, the goal of the surgeon is the prolongation of patient survival, the total eradication of local disease, and the minimization of functional deficits. In addition to treatment, this article discusses evaluation, histology, and staging.
Fatigue failure of noncemented porous-coated implants. A retrieval study. The causes of mechanical failure of five noncemented porous-coated components were studied. There were two cobalt-chromium alloy and three titanium alloy implants which fractured after 12 to 48 months. The implants included one acetabular component, and one femoral condylar, one patellar and two tibial components. Examination of the fractured surfaces revealed fatigue to be the mechanism of failure in all cases. The porous coating and the processes required for its fabrication had resulted in weakening and reduction of substrate thickness. Additional factors were stress concentration due to limited, localised bone ingrowth, and some features of the design of the implants.
Biliary pain in postcholecystectomy patients without biliary obstruction. A prospective radionuclide study. Biliary pain without obvious biliary obstruction is common in postcholecystectomy patients. We studied 20 symptomatic patients with episodes of biliary-type pain after cholecystectomy (all having undergone endoscopic retrograde cholangiography), and in 18 asymptomatic postcholecystectomy controls. We performed quantitative hepatobiliary radionuclide analysis with dimethyl-imidodiacetic acid. From a series of 90 dynamic images at 1-min intervals using a gamma camera coupled to a computer, time-activity curves were produced in regions of interest in the liver, intrahepatic biliary tree, common duct, and heart, from which quantitative biliary excretion indexes were obtained. The results demonstrate a biliary kinetic dysfunction in patients with postcholecystectomy pain without morphological abnormalities.
Effects of acute hypermagnesemia on the threshold for lidocaine-induced seizures in the rat. The effects of acute changes in plasma magnesium concentration on the threshold for lidocaine-induced seizures were evaluated in mechanically ventilated rats receiving 70% nitrous oxide and 30% oxygen. In experiment 1, male rats were intravenously administered either 0.9% sodium chloride (group I) or 5.0% magnesium sulfate to elevate plasma magnesium levels to 5.8 +/- 0.1 (group II) or 10.5 +/- 1.0 mg/dl (group III). In experiment 2, pregnant rats were intravenously administered either 0.9% sodium chloride (normomagnesemia) or magnesium sulfate, resulting in a plasma magnesium concentration of 7.8 +/- 1.4 mg/dl. Thirty minutes later, a continuous intravenous infusion of lidocaine (2.3 mg/kg per minute) was begun in both experiments. Biparietal electroencephalographic activity was monitored continuously. At the onset of electroencephalographic seizure activity, arterial plasma magnesium and lidocaine concentrations were measured. In groups I and III (experiment 1), brain parenchymal magnesium was also assayed. There were no differences in plasma lidocaine concentrations (in experiments 1 or 2) between saline solution and hypermagnesemic groups at onset of seizures. Brain magnesium level was unaltered by magnesium sulfate infusion. We conclude that acute administration of magnesium sulfate alters neither brain magnesium level nor the plasma lidocaine concentration associated with onset of electroencephalographic seizures.
A study of the effectiveness of the iron-chelating agent deferoxamine as vasospasm prophylaxis in a rabbit model of subarachnoid hemorrhage. The pathogenesis of cerebral vasospasm occurring after subarachnoid hemorrhage (SAH) is unknown. Several lines of experimentation have suggested a free radical mechanism in the etiology of vasospasm. Iron is an important catalyst in the generation of free radicals and lipid peroxides in response to tissue injury. We hypothesize that the elaboration of iron from the subarachnoid clot might result in enhanced generation of free radicals and lipid peroxidation. If so, then treatment with deferoxamine, an iron-chelating compound, might reduce the formation of free radicals and thereby ameliorate vasospasm. This hypothesis was examined in a rabbit model of experimental cerebral vasospasm. New Zealand White rabbits were divided into the following experimental groups: control (normal) animals (n = 7), control animals treated with deferoxamine (n = 3), animals subjected to SAH and killed on Day 2 (n = 7), animals subjected to SAH on Day 2 and treated with deferoxamine (n = 9), animals subjected to SAH killed on Day 3 (n = 7), and animals subjected to SAH on Day 3 and treated with deferoxamine (n = 7). Deferoxamine treatment (50 mg/kg/8 hours) was begun 16 hours before the induction of SAH and continued until the animals were killed by perfusion fixation. The basilar artery caliber was assessed using morphometric techniques. The diameter of the basilar arteries in the control animals was 0.64 +/- 0.02 mm. Deferoxamine treatment alone did not alter the artery diameter.
Transcriptional regulation of ferritin messenger ribonucleic acid levels by insulin in cultured rat glioma cells. Recent data have shown that ferritin, a ubiquitous protein, has a role as a regulator of cellular differentiation. In the present study we have investigated the expression of ferritin mRNAs in cultured C6 cells, a rat glioma cell line, in response to insulin, which has an important role in cellular growth and differentiation. Insulin stimulated steady state levels of both ferritin heavy chain and ferritin light chain mRNAs. An increase in the level of ferritin heavy or light chain mRNA was detected after 2 h of incubation with insulin, and a plateau was reached after 48 h for heavy chain mRNA and after 72 h for light chain mRNA. The responses were dose-dependent and were maximal at 100 nM for both mRNAs. Treatment of cells with actinomycin-D showed that insulin had no effect on the posttranscriptional stability of these mRNAs. Actinomycin-D inhibited insulin-induced accumulation of both mRNAs, suggesting transcriptional stimulation of ferritin genes by insulin. A nuclear run-on assay showed that the insulin-induced increase in ferritin heavy chain mRNA was due to an increase in the rate of gene transcription. We also demonstrated that insulin-like growth factor-I (IGF-I) increased ferritin heavy and light chain mRNA levels in a dose-dependent fashion, and that the maximum effect was obtained at a concentration of 10 nM on both mRNA levels. IGF-I was not only 10-fold more potent, but the absolute level of maximum stimulation was also about 2-fold greater than that for insulin. The combination of insulin (100 nM) and IGF-I (10 nM) showed no additive effect. The results suggested that the ferritin heavy and light chain genes are transcriptionally regulated by insulin and influenced by IGF-I.
Psychogenic purpura (autoerythrocyte sensitization): an unsolved dilemma. Experience at University Hospitals of Cleveland with 71 cases of Gardner and Diamond's syndrome of autoerythrocyte sensitization is reviewed. Gardner and Diamond attributed the pathogenesis of the inflammatory bruises typical of this syndrome to sensitization to the stroma of the patients' own erythrocytes, as demonstrated by reproduction of the lesion on intracutaneous injection of erythrocytic stroma. Nearly all the cases my colleagues and I have seen were in adult women, in whom the onset of inflammatory bruising could often be precisely dated, frequently some weeks after an injury or surgical procedure or, more often, severe emotional stress. Bouts of bruising were often preceded by sensations localized to the affected site. Cutaneous responses to the injection of erythrocytes were erratic. The patients described a wide range of both hemorrhagic and nonhemorrhagic complaints, including, among others, severe headaches, paresthesias, repeated syncope, diplopia (sometimes monocular), and "nervousness." Psychiatric studies indicated that patients had overt depression, sexual problems, feelings of hostility, and obsessive-compulsive behavior. The patients had traits that can be described as typical of a hysterical character disorder. Therapy of autoerythrocyte sensitization--that is, psychogenic purpura--has been difficult; in younger individuals, psychiatric therapy has appeared to be beneficial.