123rc/medical_text huggingface dataset:
Application of time series analysis to circadian rhythms: effect of beta-adrenergic blockade upon heart rate and transient myocardial ischemia. Circadian variations of transient myocardial ischemia and heart rate have been identified, but the rhythms and their response to beta blockade have not been fully characterized. Time-series analysis, a mathematical technique to describe oscillatory activity occurring within a continuous data set was used, to address these issues. Nine men with coronary artery disease underwent 72 hours of ambulatory electrocardiographic monitoring during therapy with placebo or metoprolol. During administration of placebo, ischemic time and heart rate showed a primary peak with a periodicity of approximately 24 hours with a tight coupling between the 2 variables and a secondary peak with a periodicity of 5 to 8 hours. During metoprolol therapy, heart rate and ischemic variation were reduced and the 24-hour periodicity for heart rate only remained. The 24-hour periodicity for ischemia was eliminated, but the data with 5- to 8-hour periodicity became the major component of the signal.
Induction of RNA-stabilized DNA conformers by transcription of an immunoglobulin switch region A deletion DNA rearrangement is associated with immunoglobulin class switching from IgM to IgG, IgA or IgE This recombination occurs in immunoglobulin switch regions, which are complex, highly repetitive regions of DNA. As switch regions become transcriptionally active just before switch recombination, analysis of the behaviour of these sequences during transcription could elucidate the mechanism of switch recombination. Here, we report that transcription of a supercoiled plasmid containing the murine IgA switch region (S alpha) leads to a loss of superhelical turns. The resulting series of less supercoiled plasmids is stabilized by RNA-DNA hybrids formed by the nascent RNA transcripts, which remain base-paired with their DNA templates.
Excitatory amino acids in the developing brain: ontogeny, plasticity, and excitotoxicity. Besides their role as neurotransmitters, excitatory amino acids (EAAs) in the developing brain are crucially involved in plasticity and excitotoxicity which are modified by their distinct ontogeny. Along with incomplete neuritogenesis and synaptogenesis, presynaptic markers of the EAA system are immature in the developing brain; however, postsynaptic EAA system activities, particularly of the N-methyl-D-aspartate and quisqualate receptors, are transiently enhanced early in life. This transient enhancement is presumably beneficial to the immature brain because physiologic activation of the EAA system plays a critical role in plasticity of early learning and morphogenesis. At the same time, this transient hypersensitivity renders the immature brain vulnerable to pathologic excitation of the EAA system (excitotoxicity) as observed during neonatal hypoxia-ischemia.
Furosemide absorption in patients with cirrhosis. Twelve patients with cirrhosis (seven mild and five severe) were administered intravenous and oral furosemide in random order to assess its absorption and disposition. Total serum clearance (113 +/- 49 ml/min), volume of distribution (11.9 +/- 4.5 L), and elimination half-life (166 +/- 149 minutes) were similar to those reported previously in both healthy control subjects and patients with cirrhosis. Bioavailability of 58% +/- 17% (range, 37% to 82%) was comparable to that of previous studies, and there was no difference between patients with mild and those with severe cirrhosis. In 9 of 12 patients the mean absorption time was longer than the mean residence time determined after intravenous administration (mean for all patients, 203 +/- 86 versus 134 +/- 101 minutes; p less than 0.05), indicating that furosemide followed a "flip-flop" model in these patients. In all patients the mean absorption time was prolonged relative to normal subjects irrespective of the presence of edema. As such, the slower absorption of furosemide in edematous states, such as congestive heart failure and cirrhosis, does not appear to be a consequence of edema per se. Moreover, because similar changes occur in patients with congestive heart failure, it seems that diseases with diverse pathophysiology can slow furosemide absorption.
Preoperative cell-mediated immune function and the prognosis of patients with gastric carcinoma. The cell-mediated immune function of 83 patients with gastric carcinoma was assessed preoperatively and the results were compared to that of 52 patients with benign lesions. The data were subjected to an analysis in order to evaluate their prognostic significance. The abilities to induce allogeneic cytotoxicity and to produce interleukin 2 (IL2) in patients with stage IV carcinoma were significantly depressed, as compared to those in patients with benign lesions, whereas natural killer (NK) cell activity was not significantly impaired. There was no significant correlation among these immune functions. When the patients were stratified into two groups, those who had high (greater than the mean value in patients with benign lesions) and low (less than the same value) values of these immune reactivities, the survival of patients with high NK activity (greater than or equal to 43%) was significantly better, as compared to that of patients with low cytotoxicity (less than 43%). However, there was no correlation between the survival and allogeneic cytotoxicity in these patients. The high ability to produce IL2 (greater than or equal to 1.3 U/ml) correlated with the better survival in the patients, but not in the group of patients who underwent curative resection.
Brachial plexus block with a new local anaesthetic: 0.5 per cent ropivacaine A new local anaesthetic, ropivacaine hydrochloride, was used in a concentration of 0.5 per cent in 32 patients receiving a subclavian perivascular block for upper extremity surgery. One group (n = 15) received 0.5 per cent ropivacaine without epinephrine and a second group (n = 17) received 0.5 per cent ropivacaine with epinephrine in a concentration of 1:200,000. Anaesthesia was achieved in 87 per cent of the patients in both groups in all of the C5 through T1 brachial plexus dermatomes. Motor block was profound with 100 per cent of patients in both groups developing paresis at both the shoulder and hand and 100 per cent developing paralysis at the shoulder. There was a rapid initial onset of sensory block (a mean of less than four minutes for analgesia) with a prolonged duration (a mean of greater than 13 hr of analgesia). The addition of epinephrine did not significantly affect the quality or onset of sensory or motor block. The duration of sensory block was reduced by epinephrine at T1 for analgesia and at C7, C8, and T1 for anaesthesia. The duration of sensory block in the remaining brachial plexus dermatomes as well as the duration of motor block was not effected by epinephrine. There was no evidence of cardiovascular or central nervous system toxicity in either group with a mean dose of 2.5-2.6 mg.kg-1 ropivacaine.
Schnitzler's syndrome: a broader clinical spectrum. Schnitzler's syndrome is characterized by chronic urticaria, recurrent fever, bone pain, and lymphadenopathy in conjunction with a serum IgM M component in a concentration that is usually less than 10,000 mg/L. Complement activation and cryoprecipitation do not appear to be involved. We report two additional patients who share many of the characteristics of this entity. These patients differ from patients previously reported because of the markedly elevated IgM M-component concentration in one patient and the severity of anemia in the second patient. An increased frequency of IgG autoantibodies to interleukin-1-alpha has been reported by other investigators; it has been suggested that an antibody-mediated prolongation of the half-life of interleukin-1-alpha might account for some of the symptoms and signs of this disorder. However, neither the mediators involved in the induction of nonpruritic urticaria nor the role of the IgM M component has been established.
Acute experimental allergic encephalomyelitis in SJL/J mice induced by a synthetic peptide of myelin proteolipid protein. Clinical, histologic, and ultrastructural characteristics of acute experimental allergic encephalomyelitis (EAE) induced by sensitization with a synthetic peptide corresponding to mouse myelin proteolipid protein (PLP) residues 139-151 HCLGKWLGHPDKF were studied in SJL/J mice. Groups of mice were immunized with 20, 50, or 100 nmol of the peptide and were killed from seven to 28 days after sensitization or when they were moribund. Beginning on Day 9, the mice showed signs of EAE and the disease progressed rapidly to paralysis. Central nervous system (CNS) inflammation, edema, gliosis, and demyelination were found in all mice killed between Days 10 and 28 and white matter lesion areas correlated with clinical score at the time the mice were killed. Peripheral nerve roots and the cauda equina did not have lesions. Within the range studied, the severity of clinical or histologic disease was the same regardless of the PLP peptide dose. Two of ten mice immunized with 100 nmol and none of 14 mice given smaller doses of a synthetic peptide of mouse myelin basic protein (MBP) showed clinical EAE. These mice had small numbers of CNS lesions that were indistinguishable from those in PLP peptide-sensitized mice. These findings demonstrate that immunization of SJL/J mice with PLP peptide 139-151 produces a disease with the clinical and morphologic features of CNS tissue-, whole PLP-, whole MBP-, and MBP peptide-induced acute EAE. Thus, PLP is a major encephalitogen and immune reactions to epitopes of different myelin proteins may induce identical patterns of injury in the CNS.
Recurrent seizures in children with Shigella-associated convulsions. Fifty-five children with Shigella-associated convulsions were followed prospectively to investigate their risk of subsequent febrile or nonfebrile seizures. The duration of the follow-up period was between 6.9 and 14.1 years (9.7 +/- 3.1 years). No case of nonfebrile seizures and only 2 cases (3%) of subsequent febrile seizures were observed during this period. We conclude that although febrile and Shigella-associated convulsions share many clinical features, the natural history of these two conditions seems to be distinctly different. Shigella-related convulsions are not associated with an increased incidence of subsequent febrile or nonfebrile convulsions.
Quadricuspid aortic valve and aortic regurgitation diagnosed by Doppler echocardiography: report of two cases and review of the literature. Two cases of patients with quadricuspid aortic valve diagnosed by Doppler echocardiography are presented. Aortic regurgitation was detected by pulsed Doppler echocardiography in both patients. Because they were young patients, this aortic regurgitation indicated that aortic regurgitation is not necessarily a late-developing event, as has been thought previously.
A review of techniques employed to estimate the number of motor units in a muscle. Being the smallest functional units under neural control, motor units play an integral role in muscle physiology. However, at the present time, there does not exist any widely accepted technique for quantifying or estimating the number of motor units in a muscle. Specifically, the existing techniques are the increment-counting technique, a technique based on spike-triggered averaging, and a macro-EMG based technique which vary in invasiveness from noninvasive to highly invasive, respectively. We discuss each of these techniques, along with their associated shortcomings, in detail.
Effect of parenterally administered gold therapy on the course of adult rheumatoid arthritis OBJECTIVE: To describe the course of rheumatoid arthritis over 5 years in adults and to evaluate the effect of parenterally administered gold salts on that course. DESIGN: A prospective observational study of adults with rheumatoid arthritis. Data derived from annual interviews with patients from 1983 to 1988 and from physician surveys in 1983 and 1987. SETTING: Rheumatology practices in the community. PATIENTS: The study began in 1982 with 822 adults who had rheumatoid arthritis and were under the care of rheumatologists. INTERVENTIONS: Those selected by rheumatologists in the management of their patients. MEASUREMENTS: Information describing sociodemographic and clinical characteristics, course, and therapy was collected from patients and verified by physician reports. Functional status, measured by the Health Assessment Questionnaire, and the number of painful joints were used as outcome variables. Outcome variables were adjusted for age, sex, disease duration, baseline values of the outcome variable, and the use of four disease-remittive agents other than gold. MAIN RESULTS: Multivariate repeated-measures analysis of variance showed no change in the course of rheumatoid arthritis over 5 years. The use of parenteral gold for at least 2 consecutive years at the start of the observation period produced, on average, no change in the course over 5 years in the two outcome variables. CONCLUSION: In our study of a community-based population of adults with rheumatoid arthritis who were under the care of community rheumatologists, we found that there was, on average, no statistically significant change in function or number of painful joints between 1983 and 1988. Patients receiving parenteral gold therapy for at least 2 consecutive years did not show a statistically significant difference in outcome when compared with those not receiving such therapy.
Evaluation of the serum level of immunosuppressive substance in oral cancer patients. The serum level of immunosuppressive substance (IS) was studied in 40 patients with primary oral cancer and in 79 patients without cancer. Its usefulness was evaluated as a parameter for monitoring therapy as well as recurrence of the tumors. Mean values for serum IS in patients with cancer and patients without were 687 +/- 284 micrograms/mL and 464 +/- 153 micrograms/mL, respectively. Normal healthy controls had a mean value of 431 +/- 105 micrograms/mL, with the cutoff value set at 641 micrograms/mL (mean +2 SD). Patients without cancer who had a severe infectious disease showed conspicuously high serum IS levels, and these values were closely correlated with their C-reactive protein values. The positive rate of IS increased in all patients with oral cancer was 58%. The mean level of serum IS in cancer patients was significantly higher than that of the controls (P less than .01), and the level was found to be more elevated as the stage of the disease advanced (stage I to III, 48%; stage IV, 68%). Histologic analysis of the tumor cells in patients with squamous cell carcinoma (SCC) showed that the mean serum IS level of those who had poorly differentiated SCC was much higher (937 +/- 181 micrograms/mL) than that of patients with well-differentiated SCC (616 +/- 159 micrograms/mL). Patients who had recurrent or metastatic cancer, or those who died from the cancer exhibited marked elevation of the serum IS levels, whereas patients who remained free of cancer in the follow-up period showed significantly lower serum IS levels. The rise and fall of the serum IS level was closely correlated with the disease progression and/or remission. These data strongly suggest that serum IS is a useful parameter for monitoring the disease stage as well as the effect of therapy on patients with oral cancer.
Dietary predictors of symptom-associated gallstones in middle-aged women. In 1980, 88,837 women aged 34-59 y completed a semiquantitative food frequency questionnaire and were followed for 4 y. Four hundred thirty-three women reported a cholecystectomy for recent cholecystitis, and 179 reported unremoved, newly symptomatic gallstones diagnosed by ultrasound or x ray. Among the 59,306 women with Quetelet's index of relative weight less than 25 kg/m2, inverse associations were observed between intakes of vegetable fat and vegetable protein and the risk of reportedly symptomatic gallastones, after adjusting for age, Quetelet's index in 1980, weight change between 1976 and 1980, energy intake, and alcohol intake. The relative risk in the highest quintile of vegetable fat intake, as compared with the lowest quintile, was 0.6 [95% confidence interval (CI), 0.4-0.9], and the corresponding relative risk for vegetable protein intake was 0.7 (95% CI, 0.6-0.9). No significant associations were found with energy-adjusted intakes of cholesterol, animal fat, animal protein, carbohydrate, or sucrose.
Anorectal surgery in the HIV+ patient: update. Anorectal surgery in HIV+ patients historically has been viewed with a great deal of nihilism. Advances in medical therapy and better understanding of unique pathophysiologic processes have afforded the colorectal surgeon the ability to treat better and sometimes cure the anorectal complications of AIDS. We present a series of 75 consecutive surgical procedures (1-year accrual) on HIV+ (40) and CDC AIDS (22) patients. Surgical procedures, perioperative T cell counts, and outcome will be presented; 53 percent of procedures resulted in complete healing of anal wounds; 30 percent resulted in partial healing with symptomatic relief; 17 percent resulted in symptomatic relief or tissue diagnosis without appreciable wound healing. The healing rate was significantly higher in the HIV+ group (69 percent) compared to the AIDS group (26 percent). Perioperative T cell counts did not have predictive value on outcome. No patients suffered significant unexpected morbidity, mortality, or incontinence. Pathophysiologic mechanisms of several disease processes unique to HIV+ patients and data from our ongoing investigation using RNA hybridization are presented.
Chancroid and the role of genital ulcer disease in the spread of human retroviruses. Chancroid is the most prevalent form of genital ulcer disease in developing countries and is undergoing a resurgence in industrialized countries. As a result of a nonspecificity of the clinical findings, the etiologic diagnosis of genital ulcer disease requires laboratory support. Genital ulcer disease is a risk factor for the transmission of human retroviral infections. An understanding of this interaction is emerging and will impact on the treatment and control programs for the agents causing genital ulcer disease.
Transient cyst-like cortical defects following fractures in children. Medullary fat within the subperiosteal haematoma. Asymptomatic cyst-like cortical defects appearing after fractures in children have been occasionally reported. Typically, these defects appear during fracture consolidation, within the newly formed subperiosteal bone, proximal to the fracture line, do not enlarge, and progressively disappear. We have previously shown a fatty density on CT scan within the early cortical defect. We now present two additional cases in which early CT scans appeared to confirm that these transient cortical defects may consist of fat, and probably result from the inclusion of medullary fat within the subperiosteal haematoma.
Leukemia and non-Hodgkin's lymphoma and residential proximity to industrial plants. The risks of developing leukemia and non-Hodgkin's lymphoma from living near industrial facilities were evaluated among men from Iowa and Minnesota in a population-based, case-control study. We found a statistically significant increase in the risk of developing non-Hodgkin's lymphoma (RR = 1.4) and a slight, nonsignificant excess for leukemia (RR = 1.2) among individuals who lived .8-3.2 km (1/2-2 miles) from a factory. Risks were greater for certain histologic types: follicular lymphoma (RR = 1.5), acute lymphocytic leukemia (RR = 5.4), and acute myelocytic leukemia (RR = 2.2). For non-Hodgkin's lymphoma (but not for leukemia), the relative risks for those living within .8 km (1/2 mile) of a factory were similar or slightly larger than for those living .8-3.2 km (1/2-2 miles) from a factory. Risks did not increase with duration of residence near a factory. The elevated risks of non-Hodgkin's lymphoma were particularly associated with residing near stone, clay, or glass industry facilities. The risk of developing leukemia was greater among persons who resided near chemical and petroleum plants. These preliminary findings raise the possibility that general environmental exposure associated with certain industrial activities may elevate the risk of developing leukemia and non-Hodgkin's lymphoma. Evaluation of data on proximity to industrial plants from studies in other geographic locations is needed to determine whether our results represent a meaningful association.
Ciliary motility in two patients with yellow nail syndrome and recurrent sinopulmonary infections. The yellow nail syndrome (YNS) is described as a combination of yellow nails, chronic lymphedema, pleural effusions, and recurrent sinopulmonary infections, but all these features need not be present for the diagnosis. The mechanism that renders patients with this syndrome susceptible to respiratory infections is not known. To determine whether abnormal ciliary motility is a predisposing factor, in vitro ciliary beat frequency (CBF) was measured in two patients with YNS and recurrent respiratory infections. In each case, the CBF was within normal limits (12 Hz). These data suggest that abnormal ciliary motility is not a pathophysiologic mechanism of recurrent sinopulmonary infections in YNS.
The effects of etomidate on cerebral metabolism and blood flow in a canine model for hypoperfusion. The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p less than 0.05) during hypotension in all three groups (40 +/- 5, 38 +/- 3, and 27 +/- 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p less than 0.05) from 0.23 +/- 0.02 to 0.55 +/- 0.08 in the five control animals tested and from 0.33 +/- 0.02 to 0.53 +/- 0.02 in the seven animals tested in the low-dose group, but did not increase (p greater than 0.05) in the four animals tested in the high-dose group (0.24 +/- 0.03 to 0.23 +/- 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p less than 0.05): 42 +/- 3 to 21 +/- 4 ml/100 gm/min (52% +/- 12% decrease) in the five animals tested in the control group, 60 +/- 8 to 24 +/- 6 ml/100 gm/min (56% +/- 13% decrease) in the four animals tested in the low-dose group, and 55 +/- 8 to 22 +/- 3 ml/100 gm/min (60% +/- 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.