123rc/medical_text huggingface dataset:
Effect of stress on diagnosis of hypertension. Blood pressure assessment by a physician elicits an alerting reaction and a pressor response in the patient. The magnitude and time course of this response are described for a large number of hypertensive subjects in whom the assessments were performed during ambulatory intra-arterial blood pressure monitoring. In nearly all of the subjects, the physician's visit was accompanied by blood pressure and heart rate increases that peaked within 4 minutes and then declined. The response was characterized by a relatively high average value; a large between-subject variability; no relation with patient age, baseline hemodynamic values, and responses to laboratory stressors; and no attenuation with multiple repetition of the physician's visit. On the other hand, the increase in blood pressure was considerably less when blood pressure assessment was made by a nurse than when it was made by a physician; in both instances, a 10-minute wait was associated with marked reduction of the initial response. Thus, the stress inherent in usual blood pressure-measuring procedures is responsible for considerable overestimations of patients' blood pressures. There are means by which this can be minimized, although a residual error is likely to remain in most subjects. Whether the stress-devoid blood pressure is a better prognostic index than the stress-related one remains unknown.
Blue breath holding is benign. In their recent publication in this journal, Southall et al described typical cyanotic breath holding spells, both in otherwise healthy children and in those with brainstem lesions and other malformations. Their suggestions regarding possible autonomic disturbances may require further study, but they have adduced no scientific evidence to contradict the accepted view that in the intact child blue breath holding spells are benign. Those families in which an infant suffers an 'apparently life threatening event' deserve immense understanding and help, and it behoves investigators to exercise extreme care and self criticism in the presentation of new knowledge which may bear upon their management and their morale.
T-cell lymphoma and mature nephroblastoma after synchronous bilateral Wilms' tumor. A 15-year-old boy had lymphoblastic lymphoma of the left tonsil after being treated for bilateral Wilms' tumor (BWT) at 7 months of age. In addition, a fully differentiated Wilms' tumor was diagnosed in the remaining, partially nephrectomized left kidney. Development of second malignancies in patients with a history of BWT, as compared with those with unilateral Wilms' tumor, is discussed. A possible explanation for the concurrently diagnosed, fully differentiated Wilms' tumor in the remaining left kidney is suggested.
Sudden infant death syndrome and small airway occlusion: facts and a hypothesis. Respiratory failure is almost certainly the cause of death in the majority of cases of sudden infant death syndrome (SIDS), but the mechanisms leading to it have not been elucidated. SIDS shares many environmental and socioeconomic risk factors with severe forms of bronchiolitis, and the age distribution of incident cases is similar. Present knowledge of lung and airway development during infancy, determinants of peripheral airway patency, changes in lung surface activity in infants with SIDS, and fluid film dynamics in small airways are reviewed. It is hypothesized that many cases of SIDS may be due to a final episode of progressive peripheral bronchial occlusion in infants with preceding critically diminished conductance of the smaller airways.
Otolaryngologic management of patients with subdural empyema. From 1979 to 1988, 17 patients presented to Duke University Medical Center for treatment of subdural empyema. Empyemas were caused by sinusitis in 53% of the patients and by otitis media in 12%. None of those with otologic causes required mastoid drainage, while all patients with sinus infections required sinus drainage. External frontoethmoidectomies were associated with a lower incidence of frontoethmoid re-exploration (P = 0.048), and antrostomies with a lower incidence of maxillary re-exploration (P = 0.111), than were more limited drainage procedures. Sinus drainage performed simultaneously with neurosurgical drainage reduced the incidence of sinus re-exploration (P = 0.167), neurosurgical reexploration (P = 0.048), and length of hospitalization (P = 0.020).
Esophageal adenocarcinoma in a patient with surgically treated achalasia. Although squamous cell carcinoma of the esophagus occurs with increased incidence in primary achalasia, esophageal adenocarcinoma has been considered rare in this condition. We report a patient with long-standing achalasia in whom adenocarcinoma of the esophagus occurred many years after Heller esophagomyotomy, presumably related to Barrett's esophagus complicating gastro-esophageal reflux disease.
Serological arguments for classifying Raynaud's phenomenon as idiopathic. Twenty-five patients with idiopathic Raynaud's phenomenon were followed prospectively for a mean period of 48 months. Clinical and laboratory assessments were performed on admission and on followup. The sera were analyzed for the presence of autoantibodies (antinuclear, antiskeleton and antiorganelle antibodies). Sixteen patients were antinuclear antibody positive and 2 anticentromere antibody positive. Eight patients produced antivimentin, 5 antimitochondrial, 4 anti-Golgi complex, and 3 anticentriol antibodies. Eleven patients produced antidesmosome antibodies. Only one patient (anti-RNP and antidesmosome antibody positive) developed a systemic disease (mixed connective tissue disease) during followup. The initial screening of sera may help to classify Raynaud's phenomenon as idiopathic more accurately.
Management of chronic middle ear effusion with prednisone combined with trimethoprim-sulfamethoxazole. Fifty-three patients were enrolled and evaluable in a randomized, double-blinded controlled clinical trial comparing prednisone for 7 days plus trimethoprim-sulfamethoxazole (TMP/SMZ) for 30 days vs. TMP/SMZ alone in treating chronic middle ear effusion (MEE). Clearing of the effusion in both ears or in one when only one was involved was called complete resolution; clearing in one of two affected ears was called partial resolution. The outcomes 2 weeks after initiation of therapy of 26 patients initially treated with prednisone plus TMP/SMZ were complete resolution in 20, partial resolution in three, and unchanged in three. The outcomes in 27 patients initially treated with TMP/SMZ alone were complete resolution in eight, partial resolution in three, unchanged in 13 and development of acute otitis media in three (P less than 0.01 for complete resolution). Two weeks after initiation of therapy, patients with a MEE that failed to clear were crossed over to the alternative regimen. Overall 29 of 41 patients (71%) who received oral prednisone plus TMP/SMZ initially or after the crossover had complete resolution of their middle ear effusion at 2 weeks after starting prednisone and TMP/SMZ. Five of 35 (14%) patients treated with prednisone plus TMP/SMZ and one of six (17%) patients treated with TMP/SMZ alone who had complete resolution at 4 weeks required subsequent referrals for tympanostomy tubes. A course of prednisone for 7 days plus TMP/SMZ for 30 days with monthly follow-up should be considered in children with MEE persisting beyond 6-8 weeks before referral for tympanostomy tube placement.
Arterial oxygen saturation during induction of anaesthesia Three groups of 10 ASA 1 patients were studied to determine the incidence of hypoxaemia (oxygen saturation less than or equal to 90%) using pulse oximetry during induction of 'mask' anaesthesia, and whether simple oxygenation techniques could prevent its occurrence. We also surveyed all anaesthetists in three major hospitals to ascertain their techniques for this method of anaesthesia. Anaesthesia was induced in all patients with thiopentone and maintained with nitrous oxide and isoflurane. The first group received 33% oxygen in nitrous oxide as carrier gases, a second group a few normal breaths of 100% oxygen during thiopentone administration followed by 33% oxygen in nitrous oxide, while a third group received 100% oxygen after loss of eyelash reflex until spontaneous breathing was established. No patient received positive pressure ventilation before spontaneous breathing was established. Six of the 10 patients in the first group became hypoxaemic compared to none in the second group, and three patients became hypoxaemic in the third group. Thirty-seven percent of anaesthetists who responded to the survey either did not apply positive pressure ventilation before establishment of spontaneous breathing, or only did so if apnoea was prolonged. Only one anaesthetist fully pre-oxygenated patients lungs. We conclude that to avoid the likely occurrence of hypoxaemia during induction of mask anaesthesia, a minimum of a few breaths pre-oxygenation is necessary.
Radiation-induced optic neuropathy: a magnetic resonance imaging study. Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.
Functional evaluation of quadriplegic patients using a hand neuroprosthesis. The objective of this retrospective study was to compare the abilities of quadriplegic patients to complete activities of daily living with and without the use of a portable hand neuroprosthesis. The neuroprosthesis provided synthetic hand grasp through functional neuromuscular stimulation of paralyzed forearm and hand muscles. Data were obtained from telephone interviews, patient records, and videotapes. Twenty-two quadriplegic patients were included in the study; 15 were functional at a C5 spinal cord injury level and seven at a C6 level. The median success rate (ie, the percentage of patients who could complete each activity) across the ten activities was 89% with the hand neuroprosthesis but was only 49% without the hand neuroprosthesis. All patients could perform more tasks when the neuroprosthesis was used, although the relative improvement of C5 patients was larger than that of C6 patients.
Circadian rhythms in blood pressure in school-age children of normotensive and hypertensive parents. The purpose of this study was to describe the characteristics of blood pressure rhythms in school-age children and to compare the circadian mesors and amplitudes between children of normotensive parents and children of hypertensive parents. The sample consisted of 40 healthy children between 8 and 10 years old; 20 children had a parental history of hypertension and 20 did not. Blood pressure was measured every 2 hours during the day and every 90 minutes during the night for one 24-hour cycle using a Dinamap monitor equipped with an automatic printer. Cosinor analyses revealed statistically significant circadian rhythms for systolic and diastolic blood pressures in 12 of the 40 subjects. The acrophases for systolic and diastolic pressures occurred between 1200-1800 hours. The mean systolic mesor was 108.50 while the mean diastolic mesor was 61.41. The mean amplitudes were 8.85 for systolic pressure and 7.44 for diastolic pressure. No statistically significant differences in circadian mesors and amplitudes between children of normotensive parents and children of hypertensive parents were found.
Different forms of chronic childhood thrombocytopenic purpura defined by antiplatelet autoantibodies. To determine whether detection of antiplatelet autoantibodies (AAb) to glycoproteins IIb/IIIa and Ib/IX may be useful in defining different forms of chronic thrombocytopenic purpura (TP) in children, we analyzed for AAb the platelet and plasma samples from 36 children with chronic TP (mean duration 4.4 years), from 31 children with normal platelet counts at the time of blood sampling but with chronic TP in the past (mean duration 2.9 years), and from 23 adults with chronic TP; the results were correlated with the clinical data. Antiplatelet autoantibodies were detected in 26 (72.2%) of 36 children with ongoing TP, 15 (48.4%) of 31 children with TP in the past, and 12 (66.7%) of 18 adults with TP. All children with high AAb ratios (greater than 5 times the control mean + 3 SD) were more than 8 years of age at diagnosis (mean age 12.4 years compared with 7.1 years in children with moderate or negative AAb levels; p = 0.003). The results suggest that the outcome for adolescents with high platelet-associated AAb levels may be similar to that of adults, whereas younger children may have a greater chance of spontaneous remission. The children with chronic TP in the past and elevated platelet-associated AAb levels may have a "compensated" TP and therefore may be at risk for relapses. Future studies aimed at serial AAb determination throughout the patients' courses may further define TP subgroups.
Beta-carotene's effects on serum lipoproteins and immunologic indices in humans. Doses of beta-carotene for cancer-prevention trials have been chosen based on epidemiologic data. Mechanisms of the putative antineoplastic effects by beta-carotene are unknown but may involve modulation of the immune system. We measured plasma carotenoid concentrations and selected immunologic indices at baseline and at 2 and 4 wk in 50 healthy humans (5 groups of 10 each) ingesting 0, 15, 45, 180, or 300 mg beta-carotene/d for 1 mo in this randomized placebo-controlled, open-label, parallel study. Plasma beta-carotene concentrations were markedly increased by 2 wk and were correlated with dose. Beta-carotene concentrations plateaued between 2 and 4 wk except for the 300-mg group. Thus, we developed a dose-concentration curve to optimize beta-carotene-dose selection to achieve target plasma concentrations. We were unable to identify any effects of beta-carotene ingestion on the immunologic indices studied, but modest increases in high-density-lipoprotein cholesterol were observed in all beta-carotene-treated groups.
Evolving natural history of coronary artery disease in diabetes mellitus. White diabetic patients are at high risk of developing coronary artery disease (CAD). The natural history of CAD in insulin-dependent (ID) and noninsulin-dependent (NID) diabetes mellitus (DM) is reviewed to gain insight into the mechanisms responsible for the development of premature or accelerated atherosclerosis in diabetic patients. In both IDDM and NIDDM, the risk of CAD increases with lengthening duration of diabetes; the risk, however, does not grow as a constant multiple of the nondiabetic risk of CAD, suggesting that the cumulative exposure to diabetes plays a significant role as a risk factor for CAD only in a subset of patients. This is consistent with the hypothesis that the diabetic milieu has an impact on the progression of atherosclerotic lesions but not on their initiation. This hypothesis is corroborated further by the observation that CAD does not occur in diabetic patients in populations with a low risk of CAD among nondiabetic patients. The component of the diabetic milieu responsible for promotion of atherosclerotic lesions is unknown. There is evidence, however, of a direct or indirect role of hyperinsulinemia in this process.
Iliac versus cranial bone for secondary grafting of residual alveolar clefts. Secondary bone grafting of the maxilla in the mixed transitional dentition stage has become a well-accepted procedure in the surgical protocol for rehabilitation of patients with residual alveolar clefts. This retrospective study was undertaken to evaluate and compare the long-term results obtained with iliac or cranial cancellous bone graft material in the area of alveolar clefts and was based on the independent experience of two plastic surgeons from the same center using exclusively cranial or iliac cancellous bone, respectively. The criteria for surgery were similar. The surgical technique, with the exception of the bone-grafting material, also was similar, and all patients were treated by the same group of orthodontists. Fifteen patients from each group, from a total of over 100 patients, were randomly selected and included in the study. All patients were followed up from 18 to 60 months. Operative and perioperative parameters, donor-site morbidity, and long-term results were evaluated, compared, and analyzed. There were no significant differences between the two groups, and equally good results in terms of bone incorporation, tooth eruption, and appearance were obtained with both iliac and cranial bone grafts. We conclude from our study that successful bone grafting is primarily achieved by adherence to meticulous surgical technique, simultaneous closure of coexisting oronasal or palatal fistulae, use of cancellous bone particles only, and coverage of the grafts with well-vascularized flaps. The source of bone graft does not seem to primarily influence the success of the outcome.
Reviewing the unicystic ameloblastoma: report of two cases. Classification of ameloblastoma into solid, multicystic, unicystic, and peripheral types based on clinical appearance and effects has gained recent recognition. The unicystic ameloblastoma is a less encountered variant of the ameloblastoma. It appears more frequently in the second or third decade with no sexual or racial predilection. It is almost exclusively encountered asymptomatically in the posterior mandible. The following report of two cases discusses the pathophysiology, demographics, histology, and prognosis of the unicystic ameloblastoma.
Chronic calcium channel blockade prevents the progression of myocardial contractile and electrical dysfunction in the cardiomyopathic Syrian hamster. The programmed onset of myocardial dysfunction and its progression to congestive heart failure in the cardiomyopathic Syrian hamster is hallmarked by alterations in myocellular calcium regulation. To determine whether calcium channel blockade is effective in halting the progressive depression of myocardial contractile performance in this animal model of congestive heart failure, oral verapamil therapy was instituted at 50 days of age, and treatment continued for various durations until the time of study at either 150 or 250 days of age. Left ventricular papillary muscle isometric and isotonic performance, as well as transmembrane electrical characteristics, was depressed in diseased hamsters at 150 days of age and deteriorated further by 250 days of age. These changes were evidenced by prolongation of contraction duration, a marked depression in the load-velocity relation, and a significant prolongation in the repolarization phase of the transmembrane action potential. Myocardial functional and electrical alterations associated with the progression of life in myopathic hamsters were completely halted by verapamil therapy that was continuous from 50 days after birth until death by diastolic arrest, at 150 or 250 days of age. However, premature termination of verapamil treatment before death resulted in a progressive renewal of the functional and electrical alterations for the duration of drug termination. It is concluded that the pathological changes seen during the lifetime of the cardiomyopathic hamster can be prevented by continuous calcium channel blockade and that intermediate prevention can be attained by protracted verapamil therapy. Thus, chronic verapamil therapy may be a useful adjunct in the prevention of human congestive heart failure of similar etiology.
A clinicopathological study of the paraneoplastic neuromuscular syndromes associated with lung cancer. The highest incidence of remote neuromuscular disorders in cancer has previously been reported in lung carcinoma. The clinical incidence of neuromuscular disorder was estimated and correlated with muscle histology and the histological type of lung tumour in 100 patients with lung carcinoma who were studied prospectively. Thirty-five patients had small cell carcinoma and 65 patients non-small cell lung cancer. Clinically, 33 patients had a polymyopathy, of whom 18 had a cachectic myopathy and 15 had a proximal myopathy (two patients had Lambert-Eaton myasthenic syndrome, one presented with dermatomyositis and one had evidence of ectopic ACTH production). Cachexia was more common in non-small cell cancer; proximal myopathy was more common in small cell cancer. Ninety-nine patients had abnormal muscle histology; 74 had type II atrophy, 12 had type I and II atrophy, one had type I atrophy and 12 had necrosis. The majority of patients were affected sub-clinically and the clinical entities of cachectic and proximal myopathy did not correspond to previous pathological classifications. Atrophy was not related to the duration of tumour symptoms, ageing, clinical type of myopathy or histological type of lung tumour, and was statistically different from that seen in controls. Qualitatively, the presence of weight loss, muscle wasting and metastatic disease were not factors in the development of atrophy. Similarly, necrosis was not related to the type of lung tumour, the presence of metastases, ageing, weight loss, muscle wasting, duration of tumour symptoms or the clinical form of myopathy. This study demonstrates that lung carcinoma has a direct effect on the motor unit, including atrophy, a necrobiotic myopathy and Lambert-Eaton myasthenic syndrome. Clinical assessment does not accurately assess the 'remote' neuromuscular effects of cancer on the motor unit.