123rc/medical_text huggingface dataset:
In vitro activity of LY264826, a new glycopeptide antibiotic, against gram-positive bacteria isolated from patients with cancer. The in vitro activity of LY264826, a novel glycopeptide antibiotic produced by Amycolatopsis orientalis, was compared with those of vancomycin, teicoplanin, and oxacillin against 311 gram-positive clinical isolates from patients with cancer, LY264826 had lower MICs for 90% of isolates (MIC90) than vancomycin for all species tested. It was active against oxacillin-resistant isolates including Staphylococcus aureus (MIC90, 0.5 micrograms/ml), Staphylococcus haemolyticus (MIC90, 2.0 micrograms/ml), Enterococcus spp. (MIC90, 0.5 micrograms/ml), Bacillus cereus (MIC90, 0.25 micrograms/ml), and Corynebacterium jeikeium (MIC90, 0.12 micrograms/ml). For S. aureus, including oxacillin-resistant isolates, the MICs of LY264826 were similar to those of teicoplanin. For coagulase-negative staphylococci, however, LY264826 had MICs that were 4- to 32-fold lower than those of teicoplanin. Against most streptococcal species the activities of LY264826 and teicoplanin were similar. Bactericidal activity against Staphylococcus spp. and most Streptococcus pyogenes isolates was less than or equal to 1 dilution of the MIC. One isolate of S. pyogenes and all Enterococcus faecalis strains tested were tolerant of LY264826, with MBCs greater than or equal to 32-fold greater than the MICs. The addition of 50% human serum resulted in a significant increase in activity only against Staphylococcus epidermidis. Variations in pH from 6.4 to 8.4 and in inoculum from 10(3) to 10(7) CFU/ml did not significantly affect the activity of LY264826.
Initial management of trauma. The first 5 minutes. Trauma is the leading cause of death in young Americans and is responsible for the loss of more productive years of life than heart disease and cancer combined. Initial management of trauma consists of the establishment or maintenance of a patent airway, ensurance of adequate breathing, and resuscitation of the circulation. All of these are accomplished simultaneously with a cursory survey to identify immediately life-threatening injuries and to prevent permanent disability.
Both d-cis- and l-cis-diltiazem have anti-ischemic action in the isolated, perfused working rat heart. The effect of diltiazem (d-cis-diltiazem) on the ischemic myocardium was compared with that of l-cis-diltiazem, an optical isomer having less potent calcium channel-blocking action, in the isolated, perfused working rat heart. Ischemia decreased mechanical function and tissue levels of ATP and creatine phosphate, and increased tissue levels of nonesterified fatty acids (NEFA), AMP and lactate. Reperfusion did not restore mechanical function, but restored incompletely the levels of metabolites (except NEFA) that had been altered by ischemia. The ischemia-induced changes in NEFA were prevented by d-cis-diltiazem completely and by l-cis-diltiazem incompletely. Other metabolic changes induced by ischemia were attenuated by d-cis-diltiazem but not by l-cis-diltiazem. In heart pretreated with d-cis- or l-cis-diltiazem, both the mechanical function and the levels of metabolites recovered during reperfusion, the degree of recovery with both drugs being similar. These results indicate that not only d-cis-diltiazem but also l-cis-diltiazem has an anti-ischemic action probably due to inhibition of the tissue NEFA accumulation. These results also suggest that the mechanism of the protective effect of d-cis-diltiazem on the ischemic myocardium is not entirely due to the calcium channel-blocking action. Treatment with low Ca2+ (1.0 mM CaCl2) also attenuated the ischemia-induced changes. The interval between reoxygenation and start of function in the reperfused heart that had been treated with low Ca2+ was significantly longer than that with d-cis- or l-cis-diltiazem. The effect of these isomers to shorten this interval may contribute to their common anti-ischemic action.
Iliac artery stenosis and occlusion: preliminary results of treatment with Gianturco expandable metallic stents. Ten patients with atherosclerotic stenosis or occlusion of the iliac artery were treated with Gianturco expandable metallic stents. In the five cases of stenosis, only balloon dilation was performed prior to placement of stents. The five patients with occluded arteries were given intraarterial infusions of urokinase before balloon dilation and stent placement. Clinical symptoms improved in all patients, and no technical failures or complications occurred. Doppler ankle-brachial index studies were performed in nine cases, and in all nine cases the indexes improved after stent placement. During follow-up of 2-18 months (mean, 10.3 months), all arteries remained patent. Follow-up angiograms showed slight intimal thickening and no restenosis. Long-term follow-up and more clinical experience will be necessary to evaluate the efficacy of this stent. However, preliminary results suggest that the Gianturco expandable metallic stent is of value in the treatment of arterial occlusive disease.
Normalization of increased sodium sensitivity by maintenance hemodialysis. Blood pressure (BP) becomes more sodium and body fluid sensitive as renal function deteriorates. Thus, hypertension in chronic renal failure is mostly of the sodium sensitive type. We studied whether the increased sodium sensitivity (SS) can be restored to normal on the maintenance phase of hemodialysis (HD) therapy. Body weight (BW) and BP (specifically, mean arterial pressure [MAP]) were measured after HD and before the next HD, and the body fluid sensitivity (BFS) was calculated as the ratio of changes in these factors on both introduction and maintenance phases in HD patients (n = 56) who were not taking any antihypertensive drugs (BFS = delta MAP/delta BW). In a preliminary study, the amount of interdialytic sodium intake (QNa+) was measured (n = 30), and SS was calculated as the ratio of the change in MAP to QNa+ (SS = delta MAP/QNa+). Interdialytic BW gain (3.1 +/- 0.1 kg) was correlated with the amount of sodium intake (136 +/- 17 mEq), resulting in a positive relationship between BFS and SS (r = 0.79, P less than .0001). Therefore, BFS was used as an index of SS. As a whole, BFS decreased from the introduction to the maintenance phase (6.5 +/- 1.0 to 3.5 +/- 0.6 mm Hg/L, P less than .01). This decrease was marked (6.2 +/- 1.1 to 2.9 +/- 0.6 mm Hg/L, P less than .01) in patients (n = 46) whose BP was normalized in the maintenance phase, while not significant (7.9 +/- 1.9 to 6.3 +/- 1.3 mm Hg/L) in patients (n = 10) whose BP was still high.
Bilateral vocal cord teflon injection. An ineffective treatment for recurrent aspiration pneumonia. Recurrent aspiration pneumonia is a potentially lethal problem, and its treatment is controversial. A variety of procedures have been advocated to prevent aspiration. These are reviewed briefly. We have been dissatisfied with established procedures because they usually require external approaches with considerable complexity and potential complications. Therefore, we attempted to obstruct the glottic airway by injecting both vocal cords with Teflon in a series of patients with recurrent aspiration pneumonia secondary to severe neurologic impairments. Since Teflon injection of the vocal cords bilaterally did not reliably prevent aspiration, we cannot recommend it for routine use in the treatment of chronic aspiration.
Scoliosis in trisomy 18. Patients with trisomy 18 typically present with multiple congenital anomalies and most die within the first year. However, long-term survivors are not uncommon. Seventeen patients with trisomy 18 were evaluated to study the development of scoliosis associated with this disorder. There were 13 females and 4 males with ages ranging from birth to 22 years. Twelve patients died by age 2. None developed scoliosis or had vertebral anomalies. The five patients who survived beyond age 2 developed scoliosis. Curve progression was demonstrated in the patients who returned for follow-up. Bracing was not well tolerated in two patients with curves of 48 degrees and 58 degrees. Both had poor motor control and sitting ability. One patient with a 30 degree curve was successfully managed by bracing. Another patient with a severe scoliosis was successfully fused with anterior and posterior instrumentation. Patients with trisomy 18 should be carefully evaluated for scoliosis. Scoliosis in the older child, surviving beyond age 2, may be progressive and difficult to manage.
Outlook after acute myocardial infarction in the very elderly compared with that in patients aged 65 to 75 years Little is known concerning late outcome and prognostic factors after acute myocardial infarction in the very elderly (greater than 75 years of age). Accordingly, this study compared the clinical course and mortality rate for up to 1 year in a large multicenter data base that included 702 patients greater than 75 years of age (mean +/- SD 81 +/- 4 years), with a less elderly subset of 1,321 patients between 65 and 75 years of age (mean 70 +/- 3 years). The postdischarge 1 year cardiac mortality rate was 17.6% for those greater than 75 years of age compared with 12.0% for patients between 65 and 75 years of age (p less than 0.01). There were differences in the prevalence of several factors, including female gender, history of angina pectoris, history of congestive heart failure, smoking habits and incidence of congestive heart failure during hospitalization. Multivariate analyses of predictors of cardiac death in hospital survivors selected different factors as important in the two age subgroups; age was selected in the 65 to 75 year age group but was not an independent predictor in the very elderly. The survival curves beginning at day 10 for patients 65 to 75 and in those greater than 75 years old were similar for up to 90 days but diverged later. In the very elderly, 63% of late cardiac deaths were sudden or due to new myocardial infarction, similar to the causes of 67% of deaths in the younger age group.
Monitoring platelet interactions with prosthetic graft implants in a canine model. This study shows that prosthetic arterial grafts stimulate platelets for as long as 1 year after implantation in a canine model. Carotid-to-distal aorta Dacron (DuPont, Wilmington, DE) grafts (0.8 x 50.0 cm) were tunneled subcutaneously over the right dorsal side, allowing for percutaneous arterial sampling. Thromboxane B2 (TxB2) levels were evaluated at the proximal anastomosis (w), 5.0 (x), 25.0 (y), and 50.0 (z) cm distal from w, and platelet counts and mean platelet volumes were monitored at sites w and z. TxB2 levels increased after blood entered the graft and progressively increased until the blood exited at the distal anastomosis. Platelet counts did not significantly change across the graft. Over time, systemic platelet counts decreased to approximately 50% of each dog's pregraft baseline levels and remained depressed over a 1 year period. Mean platelet volumes peaked 1-3 weeks after implant and remained greater than pregraft levels. Examination of the graft luminal surface showed a developed pseudointima characteristically similar to that which develops in mature human vascular grafts. These results suggest that healed vascular grafts in canines continue to stimulate platelet release of TxB2, reduce systemic platelet counts, and increase mean platelet volumes over 1 year. These data further suggest that platelets are stimulated by the graft and consumed.
Traditional versus laparoscopic cholecystectomy. Laparoscopic cholecystectomy is a minimally invasive procedure whereby the gallbladder is removed using laparoscopic techniques. The indications are similar to those for elective traditional cholecystectomy, but selection of patients is important for success. Contraindications are currently evolving. Patients with advanced cholecystitis, abdominal sepsis, ileus, bleeding disorders, pregnancy, and morbid obesity should not undergo this procedure. The procedure requires good traditional surgical skills, as well as additional laparoscopic (and laser) skills. Operative time is slightly longer than for traditional cholecystectomy, but decreases with experience. Morbidity is low, but there is a concern about bile duct injuries. Mortality is very low (0%) and is comparable to traditional cholecystectomy (0.4%). The major advantages of laparoscopic cholecystectomy are the short hospital stay (average: 2 days) and early return to normal activity (7 days). This results in a reduction in hospital costs. Adequate training and credentialing are important processes to foster good patient outcomes.
Success of a program of routine prenatal screening for hepatitis B surface antigen: the first 2 years. Prenatal screening for hepatitis B surface antigen (HBsAg) restricted to women with defined risk factors for chronic hepatitis B virus (HBV) infection fails to identify many carriers. A centralized program of routine HBsAg screening for all pregnant women in Alberta was introduced in 1985. We collected and analysed data for the first 2 years of the program in Edmonton to determine the frequency of risk factors for HBsAg positivity, the proportion of multiparous HBsAg-positive women not identified in previous pregnancies, the efficiency and cost-effectiveness of providing immunoprophylaxis to infants at risk of HBV infection and the degree of success in inducing adequate protection. A total of 149 women (158 pregnancies) were found to be HBsAg positive. Risk factors were readily ascertainable for 85% of the women; the remaining 15% would not have been identified through risk-selective screening. The most common risk factors were Oriental ethnic origin, history of hepatitis, jaundice or multiple transfusions of blood or blood products, and occupational exposure to blood. Although 86% of the multiparous HBsAg-positive women had risk factors, only 7% had been identified in previous pregnancies. The Alberta program appears to be cost-effective. We conclude that only routine prenatal screening will identify all infants at risk of perinatal HBV infection and that a comprehensive public health program involving central laboratories, private physicians and public health staff can be highly effective and efficient in protecting infants against hepatitis B.
Experimental and clinical percutaneous angioscopy experience with dynamic angioplasty. The authors have used ultrathin angioscopes with high optical resolution to assess the effects of dynamic angioplasty in vitro and in vivo. Experimentally, angioscopy was used to study the effects of the 5F "Kensey" catheter in "normal" porcine coronary arteries (NPCA) and postmortem human coronary arteries (PMHCA). In NPCA, the catheter keeps a coaxial position. Intimal flaps (IFs) were seen in 21/23 NPCAs. They occurred with all cam rotation speeds and were usually single and small (less than 25% of lumen). Perforations in patent arteries were rare (1/23). However, when the catheter was forced against the wall by passing through a narrowing of 5F diameter (made by a band ligature), perforations were more common at higher cam speeds. The epicardium remained intact in two thirds of perforations. Angioscopy visualized perforations in only 10% of cases (1/10), the common sign being that of large and multiple intimal flaps, which were often obstructive (5/10). In PMHCAs, angioscopy was more sensitive than angiography in detecting atheromatous lesions. The authors were able to give a better assessment of the effect of dynamic angioplasty on treated lesions, including the demonstration of intimal flaps that were not visible on angiography. In vivo, they have performed percutaneous angioscopy before and after dynamic angioplasty using 8 French Kensey catheters. Angioscopy revealed features that were not shown angiographically.
Unruptured intracranial aneurysms and arteriovenous malformations: frequency of intracranial hemorrhage and relationship of lesions. Among 91 patients with unruptured intracranial arteriovenous malformations (AVM's), 16 patients had 26 unruptured intracranial saccular aneurysms. An actuarial analysis showed the risk of intracranial hemorrhage among patients with coexisting aneurysm and AVM to be 7% per year at 5 years following diagnosis compared to 1.7% for patients with AVM alone. The difference in length of survival free of hemorrhage was significant (log-rank, p less than 0.0007). Several angiographic and clinical parameters were investigated to better understand the relationship of these lesions. The aneurysms occurred in similar percentages in patients with small, medium, and large AVM's. Twenty-five aneurysms were on arteries feeding the malformation system, almost equally distributed proximally and distally. Eleven aneurysms were atypical in location, and all arose from primary or secondary branch feeders to the malformation; 24 were on enlarged feeding arteries. Eleven (16%) of the 67 patients with high-flow AVM's had associated aneurysms, compared with five (21%) of the 24 patients with low-flow AVM's. Four (16%) of 25 low-shunt malformations and 12 (18%) of 65 high-shunt malformations had associated aneurysms. All five aneurysms associated with low-shunt malformations were on a direct arterial feeder of the malformation. These data suggest that the intracranial AVM's predispose to aneurysm formation within AVM feeding systems and that the mechanism is not simply based upon the high blood flow or high arteriovenous shunt in these systems.
Hepatocyte transplantation into the lung for treatment of acute hepatic failure in the rat. The lung was investigated as a matrix for transplanted hepatocytes in the rat model. Surgically induced fulminant hepatic failure was successfully treated by injection of 5 to 7 x 10(7) isolated hepatocytes into the pulmonary parenchyma in 86% of the animals. No animal, however, survived injection of hepatocytes into the jugular vein. It was found that liver failure is a prerequisite for the intrapulmonary survival of hepatocytes. After regeneration of the native liver, the majority of hepatocytes are cleared away within 6 months.
Injuries to the cervical spine causing vertebral artery trauma: case reports. In four patients with lesions of the vertebral artery resulting from cervical spine injury, two were due to unilateral facet dislocation and two to fractures of the dens. There was one arterial occlusion with minor vertebrobasilar symptoms, and an arterial lesion with thrombosis causing embolic occlusion of the basilar artery with lethal outcome. In one patient a fresh fracture of the dens caused dislocation of C1/2 with reversible occlusion of the left and stenosis of the right vertebral artery, resulting in unconsciousness. In a patient with pseudarthrosis of the dens an aneurysm of the vertebral artery could be detected. Cerebellar or cerebral symptoms associated with cervical spine injury should be investigated by vertebral angiography because vertebral arterial injury may be more common than suspected and may simulate traumatic brain damage.
The clinical pharmacology of etoposide. Etoposide, a semisynthetic derivative of podophyllotoxin, is increasingly used to treat cancer. Etoposide is a phase-specific, cytotoxic drug acting in the late S and early G2 phases of the cell cycle. It appears to cause breaks in DNA by either an interaction with DNA-topoisomerase II or the formation of free radicals. Most studies show a biexponential decay after the intravenous (IV) administration of etoposide. The peak plasma concentrations of drug and the area under the concentration versus time curve (AUC) are linearly related to the IV dose. Considerable interpatient variability of pharmacokinetic variables exists after IV etoposide. Various metabolites of etoposide have been identified, but their detection and quantitation are disputed. Approximately 30% to 70% of an etoposide dose is excreted. The bioavailability of oral etoposide is approximately 50%, but its absorption is not linear with increasing doses within the range in clinical use. Considerable interpatient and intrapatient variability exists in the pharmacokinetics of oral etoposide. There is no evidence of etoposide accumulation after multiple consecutive doses by either the IV or oral route. The exact roles of the liver and kidney in metabolism and excretion of etoposide are uncertain. Etoposide has been shown to be a highly schedule-dependent drug in clinical studies. This, together with the phase-specific action of etoposide and its increasingly widespread use in treating cancer, makes the clinical pharmacology of this drug of great clinical importance.
Impaired insulin action on skeletal muscle metabolism in essential hypertension. Previous studies have shown that essential hypertension is frequently associated with insulin resistance. The tissues responsible for this metabolic alteration have not been defined. We tested the hypothesis that skeletal muscle is the site of insulin resistance of essential hypertension with the use of the perfused forearm technique. Eight hypertensive (age 42 +/- 3 years, body mass index 27 +/- 1 kg/m2, intra-arterial mean blood pressure 126 +/- 4 mm Hg) and seven normotensive (age 48 +/- 3 years, body mass index 26 +/- 1 kg/m2, mean blood pressure 95 +/- 4 mm Hg) male volunteers were studied. After glucose ingestion (40 g/m2), normal glucose tolerance in the patients was maintained at the expense of a heightened plasma insulin response, suggesting the presence of insulin resistance. During graded, local (intra-arterial) hyperinsulinemia encompassing the physiological range (12-120 milliunits/l), glucose uptake by forearm tissues was significantly (p less than 0.03) reduced in the hypertensive subjects as compared with the controls at each of five insulin steps, by 43% on the average. In addition, forearm lactate and pyruvate release were significantly less stimulated in the hypertensive than in the normotensive group (p less than 0.01 for both), presumably as a consequence of the decreased glucose influx. Forearm exchange of oxygen, carbon dioxide, lipid substrates (free fatty acids, glycerol, and beta-hydroxybutyrate), and potassium were similar in the hypertensive and normotensive groups in the basal state. Insulin had no effect on oxygen consumption, carbon dioxide production, and respiratory quotient in either study group, whereas it stimulated free fatty acids, glycerol, and potassium uptake to the same extent in the hypertensive and normotensive groups.
Renal vascular disease in African-Americans and other racial minorities. Hypertensive end-stage renal disease is about 10-fold more common nationwide in African-Americans than in Caucasians and 17-fold higher in some sections of the United States. These figures are alarming and require a much greater effort in understanding the causes of this disparity and improving blood pressure control in this population to prevent catastrophic renal damage. More information is also needed about the renovascular status of other minorities. Financial obstacles to antihypertensive care appear to be an important contributing factor to the disparities of end-stage renal disease in African-Americans and perhaps other minorities.