123rc/medical_text huggingface dataset:
ACE inhibition improves vagal reactivity in patients with heart failure. The deranged autonomic control of heart rate was studied in 34 patients with heart failure (New York Heart Association [NYHA] functional class II to III) by examining the carotid sinus baroreflex. The carotid sinus baroreceptors were stimulated by graded suction. The slope of the regression line between increases in cycle length and the degree of neck suction was taken as an index of baroreflex sensitivity. The reflex response is mediated by a selective increase of vagal efferent activity. Baroreflex sensitivity therefore represents a measure of vagal reactivity. Using multiple regression analysis, baroreflex sensitivity (BS) correlated positively to stroke volume index (SVI) and inversely to plasma renin activity (PRA) and to age: BS = 0.47 SVI - 0.38 PRA - 0.23 age + constant (r = 0.74; p less than 0.0005). In addition to digitalis and diuretics, angiotensin-converting enzyme (ACE) inhibitors (captopril or enalapril) were given to 16 patients for a mean of 17 +/- 3 days. The patients with hemodynamic improvement (group A) exhibited improved baroreflex sensitivity (1.4 +/- 0.4 to 3.6 +/- 1.2 msec/mm Hg; p less than 0.01). Baroreflex sensitivity remained unchanged (3.1 +/- 0.8 to 2.4 +/- 1.0 msec/mm Hg; n.s.) in the patients without hemodynamic improvement (group B). The increase in reflex sensitivity did not correlate with hemodynamic alterations. Baroreflex sensitivity during ACE inhibition (BSD) was only related to the baseline baroreflex sensitivity (BSB): BSD = 2.8 BSB - 0.46 (r = 0.84; p less than 0.005). In patients with heart failure, reflex bradycardia decreases with age and with PRA and increases with stroke volume. Chronic therapy with ACE inhibitors enhances vagal reactivity in patients with hemodynamic improvement.
[Ca2+]i transients in the cardiomyopathic hamster heart. Intracellular [Ca2+] transients were studied in isolated hearts of healthy and cardiomyopathic hamsters in late failure perfused with glucose or pyruvate. Hearts of healthy hamsters developed similar pressures when perfused with either glucose or pyruvate, and [Ca2+]i transients were comparable in amplitude when perfused with either substrate. On the other hand, hearts of cardiomyopathic hamsters in late failure developed normal pressure when perfused with pyruvate but developed depressed pressure (50%) when perfused with glucose. The amplitude of [Ca2+]i transients fell severely and was associated with a high diastolic [Ca2+]i in cardiomyopathic hamster hearts when the perfusate was switched from pyruvate to glucose. The high phosphomonoester sugars as evidenced by 31P nuclear magnetic resonance studies and the depressed oxygen consumption in the cardiomyopathic hamster hearts perfused with glucose reflect an inhibition in glycolysis and a subsequent decrease in mitochondrial activity. Without an adequate delivery of substrate to the mitochondria in the cardiomyopathic hamster, the myocardium is no longer capable of maintaining its [Ca2+]i homeostasis.
Emery-Dreifuss muscular dystrophy. Emery-Dreifuss syndrome is a rare form of muscular dystrophy associated with cardiac complications that lead to sudden death. The disorder and its potential anaesthetic implications in the management of a patient who presented for orthopaedic surgery is described.
Squamous cell carcinoma of the anus and HIV infection. We retrospectively reviewed six patients with squamous cell carcinoma of the anus (SCCA) and human immunodeficiency virus (HIV) infection treated between 1985 and 1988. All six patients were homosexual men. Five patients had AIDS and one was HIV-positive. The most common symptoms and signs were pain (n = 5), mass (n = 5), and bleeding (n = 5). The average tumor size was 3.2 cm with a range of 1-10 cm. Five tumors were located in the anal canal and one at the anodermal junction. One patient was treated with biopsy alone, one with local excision, one with wide local excision and radiation therapy, and two with diverting colostomy. The average follow-up was 8 months. Of the five AIDS patients, two died, one was transferred to a hospice facility, one was lost to follow-up, and one remains alive 1 year following treatment. The HIV-positive patient died secondary to metastatic SCCA. This group of patients raises the question of a possible association between HIV and SCCA.
Enteroclysis and small bowel series: comparison of radiation dose and examination time. Respective radiation doses and total examination and fluoroscopy times were compared for 50 patients; 25 underwent enteroclysis and 25 underwent small bowel series with (n = 17) and without (n = 8) an examination of the upper gastrointestinal (GI) tract. For enteroclysis, the mean skin entry radiation dose (12.3 rad [123 mGy]) and mean fluoroscopy time (18.4 minutes) were almost 1 1/2 times greater than those for the small bowel series with examination of the upper GI tract (8.4 rad [84 mGy]; 11.4 minutes) and almost three times greater than those for the small bowel series without upper GI examination (4.6 rad [46 mGy]; 6.3 minutes). However, the mean total examination completion time for enteroclysis (31.2 minutes) was almost half that of the small bowel series without upper GI examination (57.5 minutes) and almost four times shorter than that of the small bowel series with upper GI examination (114 minutes). The higher radiation dose of enteroclysis should be considered along with the short examination time, the age and clinical condition of the patient, and the reported higher accuracy when deciding on the appropriate radiographic examination of the small bowel.
Myocardial metabolism of fluorodeoxyglucose compared to cell membrane integrity for the potassium analogue rubidium-82 for assessing infarct size in man by PET Potassium loss from damaged myocardial cells is linearly related to CPK enzyme loss reflecting extent of necrosis. The potassium analog, rubidium-82 (82Rb), is extracted after i.v. injection and retained in viable myocardium but is not trapped or washed out of necrotic regions. To compare myocardial cell metabolism with membrane dysfunction as indicators of necrosis/viability, 43 patients with evolving myocardial infarction and coronary arteriography had positron emission tomography using fluorodeoxyglucose (FDG) and the potassium analog 82Rb. Percent of heart showing FDG defects and 82Rb washout on sequential images indicating failure to retain the potassium analogue were visually assessed and quantified by automated software. Infarct size based on rubidium kinetics correlated closely with size and location on FDG images (visual r = 0.93, automated r = 0.82), suggesting that loss of cell membrane integrity for trapping the potassium analog 82Rb parallels loss of intracellular glucose metabolism, both comparable quantitative markers of myocardial necrosis/viability.
Training, credentialling, and granting of clinical privileges for laparoscopic general surgery. Despite the lack of scientific data comparing it with traditional open operations, laparoscopic surgery has gained rapid acceptance and implementation by general surgeons. Individual hospitals, which have the responsibility for developing their own privileging criteria, are searching for guidance as to the amount and type of additional training required to grant clinical privileges in laparoscopic general surgery. Laparoscopic surgery involves techniques different from those learned during general surgery residency training. Therefore, until such techniques are regularly included in general surgery residency programs, additional training for and granting of separate privileges in laparoscopic surgery are appropriate. Adequate training for surgeons already experienced in abdominal and biliary tract surgery can be acquired through a preceptorship in diagnostic laparoscopy, attending a course in laparoscopic surgery that includes both didactic instruction and live animal experience, assisting with the procedures in humans, and being proctored and certified as competent by an experienced general surgeon.
Strain differences in baroreflex inhibition by centrally infused enalapril in old rats. To determine whether inhibition of the brain renin-angiotensin system would affect baroreflexes similarly in old rats of different strains, we compared 24-month-old male Fischer 344 and Sprague-Dawley rats. Baroreflex sensitivity was tested while the rats were awake by recording reflex heart rate responses elicited as blood pressure was elevated with phenylephrine or lowered with sodium nitroprusside. Sprague-Dawley rats had higher blood pressures and lower heart rates initially. Chronic infusion of enalapril, a converting enzyme inhibitor, into a lateral cerebral ventricle (ICV) for two weeks lowered blood pressure in Sprague-Dawley but not in Fischer 344 rats. Furthermore, reflex bradycardia was unaffected in either rat strain, but reflex tachycardia was selectively suppressed in Fischer 344 rats. Thus, although time controls were not done to rule out spontaneous changes during the 14-day infusion period, these results suggest that central cardiovascular regulation does not change similarly with age in these two rat strains. As removal of the brain renin-angiotensin system lowered blood pressure in one strain and inhibited reflex tachycardia in the other, the divergence could mean that the brain renin-angiotensin system acts differently to keep blood pressure elevated in Sprague-Dawley rats and modulate reflex tachycardia in Fischer 344 rats.
Outcome of prophylactic therapy for idiopathic anaphylaxis. OBJECTIVE: To determine the efficacy of a prophylactic regimen (prednisone, H1 blockade, and sympathomimetic amine therapy) in patients with idiopathic anaphylaxis. DESIGN: Clinical trial before and after treatment. SETTING: Referral-based allergy clinic at a major medical center. PATIENTS: Fifty-three patients with a history compatible with idiopathic anaphylaxis for at least 6 months before presentation to the allergy service and with subsequent management by the service for at least 6 months. INTERVENTIONS: Patients with frequent life-threatening symptoms were treated with a prophylactic regimen. Patients with infrequent episodes of idiopathic anaphylaxis were only treated acutely for each episode of anaphylaxis. MEASUREMENTS AND MAIN RESULTS: The results favored prophylactic treatment with prednisone for patients who were classified as generalized-frequent in the clinical outcome measures of frequency (per patient per year) of episodes (mean before treatment, 7.31 +/- 6.46; after treatment, 3.61 +/- 4.73; P less than 0.02) and emergency room visits (mean before treatment, 1.94 +/- 3.42; after treatment, 0.21 +/- 0.44; P less than 0.005) and for patients classified as angioedema-frequent in the frequency of episodes (mean before treatment, 14.93 +/- 15.89; after treatment, 2.58 +/- 2.18; P less than 0.003) and emergency room visits (mean before treatment, 0.76 +/- 1.01; after treatment, 0.07 +/- 0.11; P less than 0.025). No statistically significant difference was found for patients classified as generalized-infrequent in the frequency of episodes (mean before treatment, 2.01 +/- 1.30; after treatment, 1.36 +/- 1.79) or of the emergency room visits (mean before treatment, 0.56 +/- 0.71; after treatment, 0.32 +/- 0.75) or for patients classified as angioedema-infrequent in the frequency of episodes (mean before treatment, 1.94 +/- 1.55; after treatment, 2.03 +/- 2.16) or of emergency room visits (mean before treatment, 0.27 +/- 0.44; after treatment, 0.37 +/- 0.59). CONCLUSIONS: Prophylactic treatment with prednisone and H1 antihistamines with or without sympathomimetic amines improves clinical outcome in patients who are classified as idiopathic anaphylaxis-angioedema frequent and idiopathic anaphylaxis-generalized frequent.
Cholesterol and coronary heart disease. Future directions. The importance of high serum cholesterol levels as a risk factor for coronary heart disease and the benefit of lowering cholesterol levels for reducing risk are being increasingly accepted. A broad consensus to this effect has led to the establishment of the National Cholesterol Education Program. Although the available evidence fully justifies this program, its practical application to the American public has generated a series of new questions that must be explored. For example, it can be questioned whether reduction in coronary risk through lowering cholesterol levels extends to both sexes and all age groups. For people with high cholesterol levels, dietary modification is undoubtedly the first step of management, but the fraction of people responding adequately to dietary change remains to be determined. Finally, indications for drug therapy and choice of drugs need further exploration, particularly in the area of cost vs benefit. Thus, continuing research must be carried out in parallel with clinical and public health application of cholesterol education.
A deletion in the gene for glycoprotein IIb associated with Glanzmann's thrombasthenia. The platelet fibrinogen receptor is composed of a complex of glycoproteins (GP) IIb and IIIa on the surface of platelets. Deficient function of this receptor prevents normal platelet aggregation, resulting in Glanzmann's thrombasthenia (GT). In this paper, we describe a black thrombasthenic patient who is either homozygous or hemizygous for a deletion within the GPIIb gene. Initial Western blot analysis of platelet proteins from this patient did not detect any GPIIb, but did detect small amounts of GPIIIa of normal mobility. Quantitation of vitronectin receptor (VNR) demonstrated that this thrombasthenic patient had approximately 1.5-2 times the number of these receptors per platelet compared with controls, a finding that has previously been noted in other thrombasthenic patients with defects in GPIIb. Genomic Southern blot studies demonstrated a deletion in the GPIIb gene of approximately 4.5 kilobasepairs (kb). Analysis of the isolated GPIIb gene demonstrated that the deletion begins between two Alu repeats within intron 1 and ends in intron 9. Polymerase chain reaction (PCR) studies using platelet RNA and oligonucleotides directed to both the 5' and 3' ends of the GPIIb cDNA sequence easily detected GPIIb transcript, suggesting that the genomic deletion of exons 2-9 does not significantly decrease the level of the GPIIb mRNA. Sequence analysis of PCR-generated GPIIb cDNA showed that a cryptic AG splice acceptor sequence was being utilized, resulting in a transcript that contained a portion of introns 1 and 9, as well as having a deletion of exons 2-9. Unlike the GPIIb gene, the GPIIIa gene appears to be intact by Southern blot analysis. PCR studies using platelet RNA and oligonucleotides directed to the GPIIIa cDNA sequence demonstrated the presence of GPIIIa mRNA. In summary, the thrombasthenic state in this patient appears to be due to a GPIIb gene deletion resulting in an abnormal transcript and no detectable platelet GPIIb. Platelet GPIIIa levels were secondarily low presumably due to the known instability of GPIIIa in the absence of GPIIb.
Null cell adenoma of the pituitary with features of plurihormonality and plurimorphous differentiation. The case of a 35-year-old man with pituitary macroadenoma who was complaining of reduced sexual activity is presented. Histologic examination showed a chromophobic adenoma corresponding mainly to a null cell adenoma at the ultrastructural level. Focal plurihormonality and plurimorphous differentiation of adenoma cells were demonstrated by immunohistochemical and electron-microscopic studies. It is suggested that adenomatous null cells represent pluripotent progenitor cells capable of transforming to different hormone-producing cell types. The factors accounting for differentiating to various cell populations have yet to be elucidated.
Suprasellar pituitary adenoma arising from the pars tuberalis: case report. A rare case of suprasellar pituitary adenoma arising from the pars tuberalis in a 53-year-old woman is presented. The tumor was located exclusively above the diaphragma sellae, and no invasion into the sella turcica was noted.
Tumorigenic 3T3 cells maintain an alkaline intracellular pH under physiological conditions. One of the earliest events in the response of mammalian cells to mitogens is activation of Na+/H+ exchange, which increases intracellular pH (pHin) in the absence of HCO3- or at external pH values below 7.2. The proliferative response can be blocked by preventing the pHin increase; yet, the proliferative response cannot be stimulated by artificially raising pHin with weak bases or high medium pH. These observations support the hypothesis that optimal pHin is a necessary, but not sufficient, component of the proliferative-response sequence. This hypothesis has recently been challenged by the observation that transfection of NIH 3T3 cells with yeast H(+)-ATPase renders them tumorigenic. Although previous measurements indicated that these transfected cells maintain a higher pHin in the absence of HCO3-, whether H(+)-ATPase transfection raised the pHin under physiologically relevant conditions was not known. The current report shows that these transfected cells do maintain a higher pHin than control cells in the presence of HCO3-, supporting the possibility that elevated pHin is a proliferative trigger in situ. We also show that these cells are serum-independent for growth and that they glycolyze much more rapidly than phenotypically normal cells.
Manometric evaluation of jejunal limb after total gastrectomy and Roux-Orr anastomosis for gastric cancer. Total gastrectomy with Roux-Orr anastomosis is frequently performed for gastric cancer. Since intestinal motility of the Roux limb has never been evaluated after this operation, pressure activity was investigated in the Roux limb of ten patients (aged 51-77 years) who had undergone total gastrectomy and Roux-Orr reconstruction. Investigations were carried out during a 6-h fast and 3 h after a 605 kcal mixed meal. During fasting only two patients had activity fronts and these were abnormal. All ten patients displayed non-propagating bursts of contractions and three had discrete clustered contractions and high amplitude jejunal contractions. The fed state was characterized by a severely reduced motor activity pattern and other abnormalities. Total gastrectomy with Roux-Orr anastomoses provokes a relatively severe disturbance in intestinal activity.
Pediatric HIV disease. The newest chronic illness of childhood. HIV disease has emerged as a major chronic illness of childhood. Children with HIV infection and children with other chronic health impairments have much in common, including the need for comprehensive, multidisciplinary, coordinated care that includes special attention to the psychosocial effects on the child and family. However, because the mother and often the father and siblings share this lethal viral infection, the impact of HIV disease upon the family surpasses that of virtually all other chronic conditions. This is compounded by the association of the disease with drug use, its preponderance among the most disenfranchised populations in the United States, and the persistent public fear and discrimination surrounding AIDS. We have made substantial progress already in the medical management of this infection, and while we await the development of more effective therapies, we already have the tools and knowledge in hand to help these families.
Effects of n-3 fatty acids in essential hypertension. We examined the effects on blood pressure, plasma lipoproteins, and platelet function when marine oil supplements (rich in n-3 fatty acids) or vegetable oil supplements (rich in n-6 fatty acids) were added to the usual diets of patients with mild essential hypertension. In a randomized, double-blind, parallel-group study, patients received 50 g of either marine oil (n = 8) or vegetable oil (n = 8) daily for 6 weeks following a baseline observation period. Diastolic blood pressure declined during treatment with fish oil (mean +/- SEM, 96 +/- 2 v 89 +/- 2 mm Hg, P = .02), but did not change with vegetable oil (92 +/- 1 v 94 +/- 1 mm Hg). Systolic blood pressure did not change significantly during either treatment. Serum triglycerides declined (by approximately 30%) in patients receiving only marine oil, but total cholesterol, LDL-, HDL-, HDL2-, and HDL3-cholesterol-subfractions and apolipoproteins A-I and B were unchanged in both treatment groups. Bleeding time increased by 33% during treatment with marine oil but did not change with vegetable oil supplements. Marine oil did not alter in vitro platelet aggregation thresholds. The lack of a significant correlation between blood pressure changes and platelet membrane fluidity, plasma renin activity, aldosterone, norepinephrine, or epinephrine suggests that these variables did not mediate the antihypertensive effect of the marine oil. We conclude that large doses of marine oil reduce diastolic blood pressure, lower triglycerides, and increase bleeding time in patients with mild hypertension.
Lyme disease: neurologic and ophthalmic manifestations. Lyme disease is tick-borne infection which produces early and late manifestations in many organ systems. Prominent symptoms and signs occur in skin, heart, joints and nervous system. Many ocular and neuro-ophthalmic abnormalities recently have been attributed to Lyme disease, but some cases have not been well established as direct sequelae. This review of the contemporary state of knowledge about Lyme disease was undertaken so that more rigorous criteria can be applied in future diagnosis.
Semantic deterioration in Alzheimer's: the patterns to expect. Differentiating language changes between the normal aged and those in the early stages of dementia is never simple. Knowing the differences and what to expect can aid in making this diagnosis.
The operative management of coexisting thyroid and parathyroid disease. Three hundred eight patients who underwent operation for hyperparathyroidism were studied. Fifty-two (17%) were identified who had a concomitant thyroid nodule. All 52 underwent parathyroidectomy and thyroid resection in a single operation. Eleven of these patients (21% of those with a thyroid nodule) had differentiated thyroid cancer. One patient with parathyroid hyperplasia developed permanent hypocalcemia. None had permanent vocal cord paralysis and none required tracheostomy. Thorough visual inspection and palpation of the entire thyroid gland should be performed during operations for hyperparathyroidism. Incidentally discovered thyroid nodules should prompt formal lobectomy with frozen section diagnosis; unanticipated thyroid malignancies should then be treated as independent entities. Treating simultaneous hyperparathyroidism and nodular thyroid disease with a single operation can be done safely; it avoids the expense and risk associated with neck reexploration and can detect unsuspected cancers.
Impact of anatomical radical prostatectomy on urinary continence. Urinary continence following an anatomical approach to radical prostatectomy was evaluated in 593 consecutive patients, 547 (92%) of whom achieved complete urinary control. Stress incontinence was present in 46 patients (8%), of whom 34 (6%) wore 1 or fewer pads per day and 2 (0.3%) required placement of an artificial sphincter. No patient was totally incontinent. Age, weight of the prostate, prior transurethral resection of the prostate, pathological stage and preservation or wide excision of the neurovascular bundles had no significant influence on preservation of urinary control. These data suggest that anatomical factors rather than preservation of autonomic innervation may be responsible for the improved urinary control associated with an anatomical approach to radical prostatectomy.