Acute hypoxic encephalopathy in the full-term newborn: correlation between Magnetic Resonance Spectroscopy and neurological evaluation at short and long term

PURPOSE: To determine which brain metabolite ratios have the strongest correlation with poor neurological outcome in newborns with perinatal asphyxia, whether the correlation is stronger with basal ganglia (BG) and whether a combined approach using Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) can be used to evaluate the severity of neonatal asphyxia. MATERIALS AND METHODS: Twenty newborns with perinatal asphyxia were studied within the first week from the hypoxic insult with MRI and MRS. The MRS variables were compared with the assessment of general movements (GMs). The brain metabolite levels measured by MRS were N-acetylaspartate (NAA), creatine (Cr), choline (Cho) and lactate and the ratios NAA to Cr, Lac to Cr, Cho to Cr, mI to Cr. RESULTS: High lactate levels and low NAA levels were found in the newborns with the worst outcome; the levels in newborns with good outcome were within normal limits. CONCLUSIONS: Correlations between NAA/Cr and Lac/Cr ratios, general movements and outcome at 6 months are stronger in the basal ganglia regions than in the frontal border zone. The presence or absence of lactate may indicate the severity of the brain insult and the combination of MRS, MRI and evaluation of general movements may assist in localising and predicting a long-term brain injury.     

Benzo[a]pyrene at an environmentally relevant dose is slowly absorbed by, and extensively metabolized in, tracheal epithelium

While tobacco smoke has been conclusively identified as a lung carcinogen, there is much debate over which smoke constituent(s) are primarily responsible for its carcinogenicity. Previous studies in our laboratory suggested that highly lipophilic carcinogens are slowly absorbed in the thicker epithelium of the conducting airways, potentially allowing for substantial local metabolism. The bioactivation of polycyclic aromatic hydrocarbons in airway epithelium may, hence, be important in tobacco smoke-induced carcinogenesis. In the present study, the hypothesis of slow absorption and substantial local metabolic activation of highly lipophilic carcinogen in airway epithelium was tested in dogs. A single dose of tritiated benzo[a]pyrene (BaP) dissolved in a saline/phospholipid suspension was instilled in the trachea, just anterior to the carina. At intervals of a few minutes up to 30 min over a 3-h period, blood samples were drawn from the azygous vein, which drains the area around the point of instillation, and from the systemic circulation. Tissue samples were taken at the end of the experiment. The concentration of BaP with depth into the tracheal mucosa was determined with autoradiography. BaP was slowly absorbed into the trachea with a half-time of approximately 73 min, which is consistent with diffusion-limited passage through the epithelium and lead to local doses in the tracheal epithelium that were more than a 1000-fold those of other tissues. The long retention of BaP in the epithelium provided the local metabolizing enzymes with high substrate levels over a long period, resulting in extensive metabolism. At 3 h after the exposure, 23% of the BaP-equivalent activity remained in the tracheal mucosa. Of this fraction, 13% was parent compound, 28% was organic extractable, 31% was water-soluble, and 28-7% of the instilled dose was bound to tracheal tissues. These results explain the tendency of highly lipophilic carcinogens, such as BaP, to induce tumors at the site of entry and, furthermore, indicate that the highly lipophilic components of tobacco smoke and polluted air may be the most important contributors to lung tumors of the conducting airways.      

Urinary albumin excretion and transcapillary escape rate of albumin in malignancies

Transcapillary escape rate of albumin was determined in 22 patients with different malignancies. In addition, urinary albumin excretion rate was measured in 24-h urine samples using a sensitive immunoassay. Increased urinary albumin excretion was defined as ≥20 μg/min according to conventional standards. Renal glomerular filtration and tubular function was estimated by⁵¹Cr-EDTA plasma clearance and urinary beta 2-microglobulin, respectively. Median urinary albumin excretion rate was 15.0 μg/min (range 6–510 μg/min) and the frequency of increased urinary albumin excretion was 41%. This agrees with other studies showing increased albuminuria in several types of malignant diseases. Patients with advanced disease (tumour, node, metastasis (TNM) stage II–IV) had a significantly higher urinary albumin excretion rate than patients with localized disease (TNM stage I). Serum creatinine, glomerular filtration rate and urinary beta 2-microglobulin were all within normal limits. Median transcapillary escape rate of albumin was 5.5%/h (range 2–8%/h) and this level is comparable with values in healthy subjects. There was no significant difference in transcapillary escape rate between patients with elevated urinary albumin excretion and the normoalbuminuric group. Median value of the absolut outflux of albumin was 10.6 g/h with similar levels in patients with increased urinary albumin excretion and patients with normoalbuminuria. Our results indicate a high prevalence of minor glomerular dysfunction with a slightly elevated urinary albumin excretion in patients with malignancies. The normal endothelial function, as estimated by the transcapillary escape rate of albumin, suggests an overal unaffected capillary permeability and increased urinary albumin loss appears to be an isolated renal phenomenon in cancer patients.     

Chemotherapy of non-Hodgkin's lymphoma: 10 years' experience in the Southwest Oncology Group.

The Southwest Oncology Group (SWOG) has completed five studies of high-dose intermittent combination chemotherapy for the management of advanced (stage III and IV) non-Hodgkin's lymphoma involving 1143 patients from May 1966 to September 1974. Lack of uniform histopathologic interpretation precludes precise analysis of these data. Although there has been little change in complete response duration over the years of this study, there has been an overall improvement in response rate and survival though there is no statistically significant improvement in the best overall survival when compared to the Stanford experience in stage III and IV disease (1960-71). The response rate and survival in diffuse histiocytic lymphoma have improved since the first study. There is definite evidence of a plateau in the survival curve beyond 2 years. The percentage of survival at which the plateau appears has increased over the years to 40% in the most recent studies, and the survival is suggestively better than the Stanford experience (P = 0.09). Over the years there has been a distinct improvement in response rate and survival of patients with nodular lymphocytic lymphoma, although the best SWOG survival is no different than the Stanford experience (P = 0.36).     

Evidence based? Caveat emptor!

Medical practices, clinical practice guidelines, clinical performance measures and measurements, and a variety of health care-related administrative decisions, such as insurance coverage decisions, are claiming to be "evidence based" with increasing frequency. In this paper we examine the "evidence based" label; discuss how evidence ought to have been assembled, evaluated, and synthesized; and when evidence is sufficient for the "evidence-based" moniker to rightfully apply. We also highlight several considerations other than the strength of evidence that are relevant to several common types of health care-related administrative decisions and that influence the extent to which the resulting decisions are truly evidence based.     

Recombinant coagulation factor VIIa in major liver resection: a randomized, placebo-controlled, double-blind clinical trial

BACKGROUND: Prevention of bleeding episodes in noncirrhotic patients undergoing partial hepatectomy remains unsatisfactory in spite of improved surgical techniques. The authors conducted a randomized, placebo-controlled, double-blind trial to evaluate the hemostatic effect and safety of recombinant factor VIIa (rFVIIa) in major partial hepatectomy. METHODS: Two hundred four noncirrhotic patients were equally randomized to receive either 20 or 80 microg/kg rFVIIa or placebo. Partial hepatectomy was performed according to local practice at the participating centers. Patients were monitored for 7 days after surgery. Key efficacy parameters were perioperative erythrocyte requirements (using hematocrit as the transfusion trigger) and blood loss. Safety assessments included monitoring of coagulation-related parameters and Doppler examination of hepatic vessels and lower extremities. RESULTS: The proportion of patients who required perioperative red blood cell transfusion (the primary endpoint) was 37% (23 of 63) in the placebo group, 41% (26 of 63) in the 20-microg/kg group, and 25% (15 of 59) in the 80-microg/kg dose group (logistic regression model; P = 0.09). Mean erythrocyte requirements for patients receiving erythrocytes were 1,024 ml with placebo, 1,354 ml with 20 microg/kg rFVIIa, and 1,036 ml with 80 microg/kg rFVIIa (P = 0.78). Mean intraoperative blood loss was 1,422 ml with placebo, 1,372 ml with 20 microg/kg rFVIIa, and 1,073 ml with 80 microg/kg rFVIIa (P = 0.07). The reduction in hematocrit during surgery was smallest in the 80-microg/kg group, with a significant overall effect of treatment (P = 0.04). CONCLUSIONS: Recombinant factor VIIa dosing did not result in a statistically significant reduction in either the number of patients transfused or the volume of blood products administered. No safety issues were identified.