123rc/medical_text huggingface dataset:
Preservation of oscillations in postocclusive reactive hyperemia. Oscillations in skin blood flow (SkBF) during postocclusive reactive hyperemia are believed to be due to locally mediated events in the microcirculation. We characterized the activity of these oscillations in nine healthy young men who underwent 0, 10, and 40 Torr of lower body negative pressure (LBNP). Postocclusive SkBF was estimated in both forearms simultaneously in a stable thermal environment with laser-Doppler velocimetry. Periodic behavior of SkBF was characterized by frequency-domain power spectral analysis. LBNP at 40 Torr increased heart rate, decreased forearm blood flow, and decreased postocclusive SkBF amplitude but did not change the periodicity of SkBF in the frequency response range that is characteristic of postischemic SkBF oscillations (0.11 +/- 0.04 Hz). We observed that LBNP did not alter the frequency response of the postocclusive SkBF as quantified in the periodogram, even though the amplitude of the SkBF was markedly diminished as a part of the general decrease in arm blood flow. We found inferential evidence for a disseminated common pacemaker mechanism that performs similarly at distant sites. We conclude that the LBNP baroreflex-mediated modulation of SkBF reduces the amplitude but does not change the frequency behavior of postocclusive SkBF. We propose on the basis of our findings that the preservation of vasomotion suggests that this phenomenon is an adaptation to the ischemic changes induced by disruption of blood flow.
Angioplasty of occluded coronary arteries: use of thin shaft balloon over-the-wire system without pre-dilatation. A retrospective review was done on 13 consecutive patients who underwent PTCA of totally occluded coronary arteries using a recently released thin shaft balloon over-the-wire angioplasty system. Balloon size was determined by the closest fit to the arterial size and used without predilatation techniques. This technique was initially successful in 12 patients with only 2 clinically insignificant episodes of distal embolization and one probable early reclosure. Using thin shaft angioplasty systems, balloon dilatation of totally occluded coronary arteries can be done safely with a single balloon in many cases resulting in simplified procedures and economic benefits.
Subclavian artery to innominate vein fistula after insertion of a hemodialysis catheter. Insertion of hemodialysis catheters for temporary use is now preferentially performed by percutaneous infraclavicular subclavian vein catheterization. This method involves passage of a stiff dilator and a peel-away sheath over a guide wire, and is usually carried out without fluoroscopy. For the most part this has proved to be a valuable and safe approach. However, a small incidence of major complications occurs, which needs to be emphasized. Sixteen cases of arteriovenous fistulas between the subclavian artery or its branches and the subclavian vein have been reported so far in the literature. To date only one case of subclavian artery to innominate vein fistula has been reported. We report the second case with this complication and suggest possible preventive measures.
Platelet thromboxane release and delayed cerebral ischemia in patients with subarachnoid hemorrhage. Adenosine diphosphate-induced platelet aggregation and associated thromboxane B2 release were studied in 52 patients with subarachnoid hemorrhage (SAH) in order to detect a possible association between altered platelet function and development of cerebral ischemic complications after SAH. Compared to the values on admission, the patients showed significantly increased platelet aggregability (p less than 0.05) and thromboxane release (p less than 0.001) 1 to 2 weeks after SAH. The highest values of thromboxane release were seen in patients who deteriorated due to delayed cerebral ischemia with a permanent neurological deficit. Thromboxane release was significantly higher (p less than 0.05) before the onset of severe delayed ischemia in six patients with preoperative ischemia compared to the patients without delayed ischemia. In five others, both ischemic deterioration and elevated thromboxane release occurred after operation. These patients had preoperative values similar to the values in those without ischemic symptoms. The observations suggest that increased platelet aggregability and thromboxane release are associated with delayed cerebral ischemia both before and after surgery.
A prospective, double-blind study of metoclopramide hydrochloride for the control of migraine in the emergency department STUDY OBJECTIVE: To determine the effectiveness of IV metoclopramide as sole therapy for relieving the pain of acute migraine in the emergency department. DESIGN: Prospective study. Fifty patients were divided randomly into subjects and placebo controls with blinding of the treating physician and the patient. PARTICIPANTS: Patients presenting to the ED with migraine requiring parenteral treatment. INTERVENTIONS: Subjects received 10 mg IV metoclopramide and controls received IV normal saline; patient assessment of relief was followed by means of a numerical scale. MEASUREMENTS AND MAIN RESULTS: Sixty-seven percent of subjects compared with 19% of controls had effective pain relief within one hour (P less than .001). Subjects achieved mean relief scores of 2.46 compared with 1.69 for controls (P less than .02). No significant side effects were observed. CONCLUSION: IV metoclopramide as a single agent is effective and safe therapy for migraine in the ED.
Doxazosin in the treatment of essential hypertension in general medical practice in Latin America. This Latin American study assessed in the general practice setting the efficacy and tolerance of once-daily doxazosin in the treatment of mild or moderate essential hypertension (sitting diastolic blood pressure, 95 to 115 mm Hg). Patients (n = 220) were treated with doxazosin for 12 weeks as monotherapy or in combination with other antihypertensive agents. At the final visit, doxazosin produced a mean change in sitting systolic/diastolic blood pressure of -18.4/-14.4 mm Hg, at a mean daily dose of 4.3 mg. One hundred sixty-three (77.6%) of the 210 evaluable patients were considered a therapeutic success. Lipid analyses identified a statistically significant (p = 0.02) reduction in total serum cholesterol (4.85%) and an overall decrease in triglyceride levels (5.12%). According to the Framingham Heart Study equation, doxazosin produced a highly significant (p less than 0.001) 20% reduction in the calculated probability of developing coronary heart disease in 10 years. Of the 220 patients evaluated, 54 (24.5%) reported side effects that were considered related to treatment. Ten (4.5%) patients reported side effects unrelated to treatment and 37 (16.8%) reported events of unknown relationship. Most side effects were mild or moderate and were tolerated or disappeared with continued treatment. Nine patients (4.1%) were discontinued from therapy and in 13 (5.9%) the dose was reduced. The most prevalent side effects were headache and dizziness. The investigator's overall assessment of antihypertensive efficacy was excellent or good for 176 patients (80.4%); tolerance was considered excellent or good in 193 patients (88.5%).
Community lifestyle characteristics and risk of acute lymphoblastic leukaemia in children. High rates of leukaemia in children and young people have been associated with features of community isolation and population growth. Incidence data collected by two specialist registries were used to compare incidence rates at ward level with relevant ward characteristics derived from routine census and Ordnance Survey data for England and Wales. An excess risk of childhood acute lymphoblastic leukaemia (ALL) was found for wards which are farthest from large urban centres. The excess was greatest for wards of higher socioeconomic status and for children aged 1-7 years (the childhood peak), for which a two-fold excess was seen. These findings in general support the hypothesis that childhood leukaemia has an infectious aetiology.
Cardiac fluoroscopy for the diagnosis of coronary artery disease: a meta analytic review. To evaluate variability in the reported accuracy of fluoroscopically detected coronary calcific deposits for predicting angiographic coronary disease, we applied meta analysis to 13 consecutively published reports comparing the results of cardiac fluoroscopy with coronary angiography. Population characteristics and technical and methodologic factors were analyzed. Sensitivity and specificity for predicting serious coronary disease compare quite well with those from the literature on the exercise ECG and the exercise thallium scintigram. Sensitivity increases and specificity decreases more significantly with patient age, and sensitivity is paradoxically lower in laboratories testing patients with more severe disease, as well as when 70% rather than 50% diameter narrowing is used to define angiographic disease. Work-up and test review bias were also significantly related to reported accuracy.
Physician response to notification of acute problems in nursing homes. A frequently cited example of physicians' alleged disinterest in nursing home patients is their failure to respond rapidly or appropriately to telephone calls about acute events or important changes in patient status. This study of 45 SNFs and their 15 attached ICFs evaluated the length of time required to reach physicians by phone about significant clinical changes in patients' conditions and the appropriateness and timeliness of action taken by the physicians once contact was made. Calls on administrative matters, updating of orders, and similar routine calls were excluded. Seven hundred and fifty calls were identified from 24-hour nursing reports; the nature of the problem and the time and details of physicians' responses were recorded from patient charts. Judgment on the quality of physicians' responses was made by consensus of the regional UR committee except in the case of infections where decisions were based on detailed criteria developed in a previous study. The most frequent clinical problems were acute infections (32%), trauma (12%), GI tract disorders (11%), cardiorespiratory problems (10%), neurological disorders (7%), and diabetic control (7%). Results were very encouraging: 96% of physicians' call-backs and actions were judged to be timely, and 87% of physicians' actions taken were judged to be appropriate. However, actions taken were judged inappropriate for certain specific clinical problems, ie, in 22% (54/243) of infections, 24% (4/17) of CVA's, and 12% (6/49) of diabetic control problems. Implications for nursing home care and recommendations for improving the response to acute problems are discussed.
Geriatric constipation: brief update on a common problem. Constipation occurs frequently in the elderly and is often multifactorial in origin. A search for an underlying cause is necessary, and can often be found by taking an adequate history and performing a thorough physical examination. A minority of patients require further investigation, guided by the clinical setting. Management should be directed at correcting the underlying cause and providing dietary advice and, less commonly, medication to allow restoration of a normal bowel habit.
Efficacy and safety of doxazosin in the treatment of patients with mild or moderate essential hypertension and elevated levels of cholesterol. In hypertensive patients, elevated serum cholesterol is a frequent and sinister additional coronary risk factor. Selective alpha 1-adrenoreceptor inhibitors appear to have the unique ability to control both risk factors. Forty-two patients, ages 42 to 65 years, including 21 men with sustained hypertension and elevated serum cholesterol levels, were included in a trial of monotherapy with doxazosin administered once daily (range, 1 to 16 mg). The influence of the drug on high blood pressure and elevated serum cholesterol was evaluated over a 28-week period, which consisted of a 4-week, single-blind placebo lead-in period, an open 10-week dose-adjustment period, and finally a 14-week maintenance period. Of the 39 efficacy-evaluable patients, 25 (64%) achieved adequate blood pressure control (diastolic blood pressure less than 90 mm Hg or a decrease in diastolic blood pressure greater than 10 mm Hg) at a mean daily dose of 2 mg of doxazosin. No persistent changes occurred in heart rate. In the 32 patients with evaluable lipid data, there were nonsignificant trends to an increase in high-density lipoprotein cholesterol and a reduction in total cholesterol, together with a significant reduction in serum triglyceride concentration. The combined changes in blood pressure and blood lipid levels resulted in a reduction of 36% in the calculated risk of coronary heart disease. Eleven patients reported side effects and four were withdrawn from therapy. These results confirm the antihypertensive and anticholesterolemic efficacy of once-daily treatment with doxazosin.
Vasospasm contributes to monosodium glutamate-induced headache. Consumption of monosodium glutamate has long been considered to precipitate headaches in susceptible patients. In this study the direct effects of glutamate and its metabolite, glutamine, on arterial contractility were examined using rings of rabbit aorta. In a high concentration glutamate caused significant concentration-dependent contractions (EC50, 10(-1)M; maximum tension, 188.4 +/- 33.3 mg wt tension/mg tissue). Agonists and antagonists for alpha-adrenergic, histaminergic, serotonergic, cholinergic, and GABA-nergic receptors as well as inhibition of prostaglandin synthesis failed to influence glutamate contractions. At high concentrations (10(-5)M) the calcium channel blocker, verapamil, inhibited the glutamate response. Glutamate and glutamine both exhibited concentration dependent relaxation of norepinephrine (NE), phenylephrine (PE), histamine, serotonin (5-HT), and prostaglandin F2 alpha (PGF2 alpha)-induced contractions. Kainic acid (10(-4)M), an agonist of one subpopulation of central glutamate receptor, potentiated glutamate-induced vasoconstriction; a higher concentration (10(-3)M) produced an irreversible inhibition of glutamate contractility. Only the central glutamate receptor antagonist, ketamine (10(-4)-10(-2)M), induced a reversible, concentration dependent inhibition of glutamate-induced contractions. Glutamate contractility was not dependent on extracellular calcium, an intact endothelium or neuronal function. These results demonstrate a direct effect of glutamate on peripheral arterial tone. Dietary consumption of large quantities of MSG may represent a serious health hazard to certain individuals with pre-existing vascular disease.
Surgical epicardial ablation of left ventricular pathway using sling exposure We report our experience with 43 consecutive patients with left free wall pathways operated on since December 1988 using a modified direct epicardial approach through a medial sternotomy, without the adjunct of normothermic cardiopulmonary bypass. The left atrioventricular sulcus is exposed by dislocating the heart cephalad and to the right using a sling made of a large sponge passed around the ventricle through the transverse sinus. While the arterial pressure is monitored, the heart is positioned to obtain adequate exposure without compromising the ventricular function. The left atrioventricular junction is exposed using a direct approach. The epicardium is incised along the ventricular edge and a plane of dissection is identified and opened using blunt dissection over the ventricular wall. The entire left atrioventricular junction can be exposed. After dissection, electrophysiological testing is repeated to assess accessory pathway conduction. Epicardial cryoablation was used when accessory pathway conduction was not present (42 patients). Transmural cryoablation was used under normothermic cardiopulmonary bypass when accessory pathway conduction persisted after dissection (subendocardial pathway). In all, cardiopulmonary bypass was not used in 41 patients. There was one early relapse that required transmural cryoablation. There were no complications.
Rationalisation of follow-up in patients with non-invasive bladder tumours. A preliminary report. The risk of recurrence and progression in 170 patients presenting with pTa urothelial tumours of the bladder has been estimated so that follow-up can be rationalised. Patients were followed up for between 1 and 15 years, the original pathology reviewed and those with carcinoma in situ (CIS) or dysplasia of the background urothelium excluded. Only 5 patients progressed over the whole follow-up period, giving an overall progression rate of 3%. Solitary tumours had an annual initial recurrence risk (AIR) of 0.23 in the first year; after the first year the AIR fell to approximately 0.1 but did not fall significantly in subsequent years up to 8 years. Of the 45 patients with multiple tumours, 32 suffered recurrences within the first year (AIR 0.71). Tumour grade did not influence either recurrence or progression. The results indicate that for solitary pTa tumours, less frequent endoscopic follow-up is justified but some continued surveillance after 5 disease-free years is necessary. The estimated risk of recurrence is a useful factor to consider when planning follow-up.
Coronary and left ventricular hemodynamic responses following reversal of flunitrazepam-induced sedation with flumazenil in patients with coronary artery disease. The effects of reversal of flunitrazepam-induced sedation with flumazenil on coronary hemodynamics, myocardial oxygen consumption (MVO2), and left ventricular (LV) performance were investigated, in a double-blind trial, in 12 patients with stable coronary artery disease undergoing cardiac catheterization. Coronary sinus blood flow was measured by continuous thermodilution. Arterial and coronary sinus blood were analyzed for oxygen and lactate contents. The determinants of LV performance were obtained from the cardiac output measured by thermodilution and from left heart catheterization data. To reverse flunitrazepam-induced sedation, patients were randomly allocated to receive placebo or flumazenil (by increment, up to 1 mg) at the end of procedure. In the placebo group, no significant hemodynamic changes were observed. In the flumazenil group, heart rate, cardiac index, maximum velocity of shortening, and relaxation time constant were not significantly altered. By contrast, mean aortic pressure and LV end-diastolic pressure (baselines: 90 +/- 5 and 7.3 +/- 4.1 mmHg, respectively) increased (9%, P less than 0.05 and 67%, P less than 0.05, respectively) after flumazenil administration, but these changes represented mainly a return toward presedation values. MVO2 and coronary resistance were not significantly altered, whereas CSBF increased slightly (baseline: 119 +/- 20 ml/min; increase 10%, P less than 0.05). No electrocardiographic evidence of myocardial ischemia was observed during the study. These data show that reversal of benzodiazepine effects with flumazenil is not associated with a major alteration of LV systolic function, relaxation, or coronary hemodynamics in patients with coronary artery disease. Nevertheless, it should be cautiously used when LV end-diastolic pressure is increased at the time of its administration.
Etoposide in acute leukemia. Past experience and future perspectives. Etoposide as a single agent is active in relapsed and refractory acute myelogenous leukemia (AML), with complete responses (CR) rates of 10% to 25%. The drug has been safely combined with cytarabine, azacytidine, vinca alkaloids, and anthracyclines, inducing remission rates of 20% to 60% in patients with previously treated AML. The experience with etoposide in acute lymphoblastic leukemia is less extensive, but the drug seems to be active in combination with cytarabine or aclacinomycin. In addition, etoposide is combined with cytarabine and anthracyclines for the primary treatment of AML. The response rates thus achieved are comparable with those obtained with standard regimens. A Phase I/II trial was initiated to study the efficacy of the NOVE combination (mitoxantrone [10 mg/m2/d, days 1 to 5] plus etoposide [100 mg/m2/d for 3, 4, or 5 days] in patients with refractory AML. The results showed that extended duration of etoposide administration is associated with higher CR rates. Overall, a CR rate of 43% was achieved in 61 patients. A sequential regimen with IDAC (idarubicin/cytarabine) and NOVE was designed for primary treatment of adult patients with AML. Cycles of IDAC or NOVE are applied depending on response. The results of the pilot study with this strategy were encouraging with 18 of 20 patients achieving CR. Further studies are under way to verify the efficacy of this strategy.
Transforming growth factor beta stimulates mammary adenocarcinoma cell invasion and metastatic potential. The experimental metastatic potential of 13762NF mammary adenocarcinoma clone MTLn3 was tested after pretreatment in serum-free medium containing transforming growth factor (TGF) beta 1 at 0-5000 pg/ml. Lung colonies were measured 2 weeks after inoculation in syngeneic F344 rats, and a bell-shaped dose-response curve with 2- to 3-fold increase in number of surface lung metastases was seen. Maximal enhancement occurred at the 50 pg/ml dose level. The effect was specific because addition of neutralizing anti-TGF-beta antibody blocked the stimulatory activity at all levels of TGF-beta 1 pretreatment, but when antibody was given alone, neutralizing anti-TGF-beta antibody had no effect on untreated cells. Increased metastatic potential appears to be from an increased propensity of cells to extravasate as tested in the membrane invasion culture system. MTLn3 cells penetrated reconstituted basement-membrane barriers 2- to 3.5-fold more than did untreated control cells, depending upon length of TGF-beta 1 exposure. Increased invasive potential is apparently due, in part, to a 2- to 6-fold increase in type IV collagenolytic (gelatinolytic) and a 2.4-fold increase in heparanase activity. TGF-beta 1 treatment of MTLn3 cells did not alter their growth rate or morphology in the presence of serum; however, growth was inhibited in serum-free medium. Likewise, adhesion to human umbilical vein endothelial cell monolayers or to immobilized reconstituted basement membrane or fibronectin matrices was unchanged. These results suggest that TGF-beta 1 may modulate metastatic potential of mammary tumor cells by controlling their ability to break down and penetrate basement-membrane barriers.
Osteoblastoma of the spine. A review of 75 cases. Clinical and radiologic features of 75 cases of osteoblastoma of the spine were reviewed. In addition to pain, which was the most frequent complaint, 18 patients demonstrated objective neurologic deficit, while scoliosis was observed in 17 patients. Aspirin yielded pain relief in 13 patients. Pathologic fracture was not encountered. The radiologic and histologic characteristics of osteoblastoma of the spine are indistinguishable from those arising in other sites. The typical lesion exhibited a well-defined, geographic margin with a sclerotic, frequently lobulated border. Approximately one half of the cases were predominantly lucent, the remainder displaying varying degrees of matrix mineralization. Distribution of the osteoblastomas through the spinal axis was as follows: cervical-29, thoracic-16, lumbar-17, sacral-13. Other significant findings included posterior element involvement in 73 of 75 cases, and a striking male to female ratio of 2.5 to 1.