[Usefulness of the statistical bulletin of deaths to identify extrahospital deaths in the context of a myocardial infarction population registry]

INTRODUCTION AND AIMS

This paper aimed to study the usefulness of the Statistical Bulletin of Deaths (SBD) for identifying extrahospital deaths due to acute coronary ischaemia, and to determine the most efficient strategy in the selection of death causes that appear in the SBD, which are the most efficient for the identification.

METHODS

Those extrahospital deaths, which, among the causes of death, recorded a diagnostic code indicating that they might have been caused by coronary ischaemia, were included. To study the usefulness of the death certificate we calculated the sensitivity and the positive predictive value of cardiac ischaemia. To determine the most efficient strategy for selecting causes of death we compared two selection strategies: the first, using only the basic cause of death; and the second using all the causes appearing in the SBD.

RESULTS

Of the 395 SBD selected, 161 were classed as acute heart attacks. In those SBD in which cardiac ischaemic disease was given as the basic cause of death, we obtained a sensitivity of 82.6% (CI 95%: 75.9-88.1) and a positive predictive value of 72.7% (CI 95%: 65.6-79). The most efficient strategy in SBD selection proved to be the investigation of death certificates in which cardiac ischaemia appeared as one of all the causes of death, and death certificates in which the basic cause of death was coded as diabetes mellitus, essential arterial hypertension, hypertensive heart disease, cardiac dysrhythmia, and cardiac insufficiency.

CONCLUSIONS

The information provided by death certificates for extrahospital deaths due to coronary ischaemia is reliable. A sensitive and efficient SBD selection strategy is proposed for the detection of cases.

Association of CYP2C9 genotypes leading to high enzyme activity and colorectal cancer risk

CYP2C9 enzyme activity is involved in the metabolism of substances related to colorectal cancer, and it is functionally linked to a genetic polymorphism. Two allelic variants of the CYP2C9 gene, namely CYP2C9*2 and CYP2C9*3, differ from wild-type CYP2C9*1 by single amino acid substitutions. These mutated alleles encode enzymes with altered properties that are associated with impaired metabolism. The present study evaluates the impact of CYP2C9 genotypes leading to high enzyme activity on colorectal cancer risk. For this, the frequency of allelic variants of the CYP2C9 gene was analysed in genomic DNA from 129 patients with colorectal cancer and in 150 healthy controls. Patients with colorectal cancer showed a statistically significant increase in the frequency of genotypes homozygous for the active CYP2C9*1 gene, as compared with healthy individuals. Such a high frequency is more significant among patients with cancer in proximal segments of the colon (P < 0.025; odds ratio 2.36 95% CI 1.18-4.72), and decreases in more distal tumour locations. We conclude that CYP2C9 polymorphism can be considered as a secondary risk factor for colorectal cancer in the studied population: those individuals with genotypes leading to high enzyme activity were at increased risk. The association of the CYP2C9 polymorphism to colorectal cancer risk could be related to CYP2C9-mediated metabolic activation of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines. In addition, the key role of CYP2C9 in the metabolic inactivation of non-steroidal anti- inflammatory drugs could diminish the protective effect of these drugs against colorectal cancer.

Effects of chronic treatment with acarbose on glucose and lipid metabolism in obese diabetic Wistar rats

AIMS

The effect of chronic treatment with acarbose on fasting plasma glucose, insulin, triglyceride, cholesterol and free fatty acid (FFA) concentrations, as well as on the glucose and insulin excursions during oral glucose tolerance test (OGTT), in obese diabetic Wistar (WDF) rats was investigated.

METHODS

Forty-five mature male WDF rats were randomly distributed to one of the three treatment groups (no acarbose, 20 mg and 40 mg of acarbose/100 g of chow, respectively). After 3.5, 7.5 and 11.5 months, animals were tested for glucose tolerance by means of an OGTT, and their respective metabolic profiles were determined. Control determinations were done in obese and age-matched lean animals before the start of the trial.

RESULTS

The WDF rats exhibit higher body weight and fasting blood glucose, insulin, triglyceride and cholesterol concentrations compared to lean animals. Moreover, they show marked glucose intolerance as indicated by the glucose and insulin excursions during OGTT. Interestingly, in both treated and untreated animals, a reversion of the hyperglycaemic state as well as an improvement of the glucose tolerance is observed. However, whereas in the group receiving no acarbose this is accounted for by dramatic increases in fasting plasma insulin concentrations and insulin secretion during OGTT (as indicated by the DeltaInsulin area), in rats treated with acarbose the reversion of the diabetic state takes place without increments in hormone concentration. In addition, rats treated with acarbose for 3.5 and 7.5 months show lower plasma triglyceride and FFA concentrations, and the same was observed for cholesterol at the highest dosage of the drug.

CONCLUSIONS

Chronic treatment with acarbose of WDF rats improves the glycaemic and lipidic control as well as the glucose tolerance, with a lower demand of pancreatic insulin than in untreated rats. This data suggests that the long-term modulation of glucose and insulin excursions after meals improves the insulin sensitivity in this rat strain.

A potential immune escape mechanism by melanoma cells through the activation of chemokine-induced T cell death

The immune system attempts to prevent or limit tumor growth, yet efforts to induce responses to tumors yield minimal results, rendering tumors virtually invisible to the immune system [1]. Several mechanisms may account for this subversion, including the triggering of tolerance to tumor antigens [2, 3], TGF-alpha or IL-10 production, downregulation of MHC molecules, or upregulation of FasL expression [4, 5]. Melanoma cells may in some instances use FasL expression to protect themselves against tumor-infiltrating lymphocytes (TIL) [4, 5]. Here, we show another, chemokine-dependent mechanism by which melanoma tumor cells shield themselves from immune reactions. Melanoma-inducible CCL5 (RANTES) production by infiltrating CD8 cells activates an apoptotic pathway in TIL involving cytochrome c release into the cytosol and activation of caspase-9 and -3. This process, triggered by CCL5 binding to CCR5, is not mediated by TNFalpha, Fas, or caspase-8. The effect is not unique to CCL5, as other CCR5 ligands such as CCL3 (MIP-1alpha) and CCL4 (MIP-1beta) also trigger TIL cell death, nor is it limited to melanoma cells, as it also operates in activated primary T lymphocytes. The model assigns a role to the CXC chemokine CXCL12 (SDF-1alpha) in this process, as this melanoma cell-produced chemokine upregulates CCL5 production by TIL, initiating TIL cell death.

Organochlorine pollutants in remote mountain lake waters

Hexachlorocyclohexanes (HCHs; alpha- and gamma-isomers), endosulfans (alpha- and beta-isomers and the sulfate residue), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDTs), and polychlorobiphenyls (PCBs) were measured in waters from three European remote mountain lakes situated in the Alps, Pyrenees, and Caledonian mountains. Sampling encompassed both ice-free and ice-covered periods at different water column depths. High HCH concentrations were found in all lakes, those in the Alps and Pyrenees (990-2,900 pg/L) being among the highest recorded in continental waters. Endosulfans and endosulfan sulfate (120-1,150 pg/L) were the second major group of organochlorine contaminants, showing a remarkable stability upon atmospheric long-range transport. The concentrations of HCB, DDTs, and PCB (4-8, 0.6-16, and 26-110 pg/L, respectively) were low in comparison with other continental waters. Hexachlorocyclohexanes, endosulfans, and HCB were essentially found in the dissolved phase. Phase partitioning of the more hydrophobic compounds exhibited a dependence on temperature and water-suspended particles. Comparison between different sampling seasons and water depths indicated a remarkable concentration uniformity within lake, but major interlake differences. Normalization to turnover rates showed higher interlake similarity. Preferential accumulation of the less volatile compounds in the Alp lake and significant increase of baseline contributions of organochlorine compounds and residues in the Caledonian lake are also evidenced from these turnover rates.

Bone Marrow Transplantation: Prognostic Factors of Peripheral Blood Stem Cell Mobilization with Cyclophosphamide and Filgrastim (r-metHuG-CSF): The CD34+ Cell Dose Positively Affects the Time to Hematopoietic Recovery and Supportive Requirements after High-Dose Chemotherapy

To prospectively analyze factors that influence peripheral blood stem cell (PBSC) collection and hematopoietic recovery after high-dose chemotherapy (HDC), 39 patients received cyclophosphamide 4 g/m(2) and rHuG-CSF (Filgrastim) 5 &mgr;g/kg/day. Leukapheresis was started when CD34(+) cells/mL were > 5 x 10(3). A minimum of 2 x 10(6) CD34(+) cells/kg was collected. Median steady-state bone marrow CD34(+) cell percentage was 0.8% (range, 0.1 to 6). Thirty-two patients received HDC with autologous PBSC transplantation plus Filgrastim. A median of 2 (range, 0 to 6) leukapheresis per patient were performed and a median of 6.3 x 10(6) CD34(+) cells/kg (range, 0 to 44.4) collected; four patients failed to mobilize CD34(+) cells. The number of cycles of prior chemotherapy had an inverse correlation with the number CD34(+) cells/kg collected (r = -0.38; p < 0.005). Patients with <7 cycles had a higher predictability for onset of leukapheresis than patients with (3) 7 (93% versus 50%; p < 0.005). The four patients who failed to mobilize had received >/=7 cycles. The number of CD34(+) cells/kg infused after HDC had an inverse correlation with days to recovery to 0.5 x 10(9) neutrophils/L and 20 x 10(9) platelets/L (r = -0.68 and -0.56; p < 0.005). The effect of these factors on mobilization and hematopoietic recovery were confirmed by multivariate analysis. Requirements for supportive measures were significantly lower in patients given a higher dose of CD34(+) cells/kg. Therefore, PBSC collection should be planned early in the course of chemotherapy. Larger number of CD34(+) cells/kg determined a more rapid hematopoietic recovery and a decrease of required supportive measures.

Bcl-2 targets protein phosphatase 1 alpha to Bad

The diverse forms of protein phosphatase 1 (PP1) in vivo result from the association of the catalytic subunit with different regulatory subunits. We recently have described that PP1alpha is a Ras-activated Bad phosphatase that regulates IL-2 deprivation-induced apoptosis. With the yeast two-hybrid system, GST fusion proteins, indirect immunofluorescence, and coimmunoprecipitation, we found that Bcl-2 interacts with PP1alpha and Bad. In contrast, Bad did not interact with 14-3-3 protein. Bcl-2 depletion decreased phosphatase activity and association of PP1alpha to Bad. Bcl-2 contains the RIVAF motif, analogous to the well characterized R/KXV/IXF consensus motif shared by most PP1-interacting proteins. This sequence is involved in the binding of Bcl-2 to PP1alpha. Disruption of Bcl-2/PP1alpha association strongly decreased Bcl-2 and Bad-associated phosphatase activity and formation of the trimolecular complex. These results suggest that Bcl-2 targets PP1alpha to Bad.

Avalanches in one-dimensional piles with different types of bases

We perform a systematic experimental study of the influence of the type of base on the avalanche dynamics of slowly driven 1D ball piles. The control of base details allows us to explore a wide spectrum of pile structures and dynamics. The scaling properties of the observed avalanche distributions suggest that self-organized critical behavior is approached as the "base-induced" disorder at the pile profile increases.

Efficacy of N-acetylcysteine to reduce the effects of aflatoxin B1 intoxication in broiler chickens

N-acetylcysteine (NAC) has been used safely in humans and in other mammals as an antidote against several toxic and carcinogenic agents, including aflatoxin B1 (AFB1). The aim of this study was to evaluate the capability of dietary supplementation with NAC to ameliorate the effects of subacute intoxication with AFB1 in broiler chickens. One hundred twenty male Hubbard 1-d-old chickens were allocated into one of four dietary treatments: 1) control group without treatment, 2) purified AFB1 added to diet (3 mg/kg of feed) for 21 d, 3) NAC (800 mg/kg BW, daily), or 4) AFB1 plus NAC at the same doses as Groups 2 and 3. Broilers treated with AFB1 plus NAC were shown to be partially protected against deleterious effects on BW (57.8%), daily weight gain (49.1%), feed conversion index (21.4%), plasma and hepatic total protein concentration (45.2, 66.7%), plasma alanine aminotransferase (67.4%), hepatic glutathione-S-transferase (18.8%), and reduced glutathione liver concentration (75.0%). In addition, they showed less intense liver fading, friable texture, and microvesicular steatosis. In the kidney, thickening of glomerular basement membrane was also less severe in NAC+AFB1-treated chickens than in AFB1-treated chickens. Our results suggest that NAC provided protection against negative effects on performance, liver and renal damage, and biochemical alterations induced by AFB1 in broiler chickens. Effects of NAC alone on chick performance were also evaluated. Addition of NAC to diet (800 mg/kg BW) did not negatively affect feed consumption, conversion index, or serum chemistry and did not induce structural changes in the liver or kidney.

Receptor dimerization: a key step in chemokine signaling

Chemokines exert their effects through their interaction with seven transmembrane domain receptors coupled to G-proteins, GPCRs. Such receptor ligation leads to the regulation of numerous activities where chemokines play a key role, including hematopoiesis, T-cell activation, angiogenesis, inflammatory diseases or HIV-1 infection. Here we discuss the molecular mechanisms that underlie chemokine receptor activation. As occurs with other GPCRs, chemokines initiate the signaling cascades by inducing receptor dimerization. This dimerization enables the activation of the JAK/STAT pathway which allows the subsequent triggering of G-protein dependent signaling events. This mechanism provides a new context to explain some of the activities exerted by chemokines and introduces new targets for the development of drugs to fight those diseases were chemokines are implicated, such as inflammation and AIDS.

Complementary effects of Mediterranean diet and moderate red wine intake on haemostatic cardiovascular risk factors

OBJECTIVES

To compare the effect of alcohol-free Mediterranean-type diet (MD) and high-fat diet (HFD) on plasma concentration of emergent haemostatic cardiovascular risk factors (HCVRF). Also, to test if red wine supplementation modifies HCVRF, independent of diet.

DESIGN, SUBJECTS AND INTERVENTION

Controlled prospective intervention study. Two groups, each of 21 healthy male university students (22+/-3.4 y), received either MD or HFD for 90 days. Between days 30 and 60, both diets were supplemented with 240 ml/day of red wine. Baseline and T30, T60 and T90-day samples were drawn. No drop out from the study was observed.

SETTING

University campus and outpatient nutrition clinic.

RESULTS

Volunteers on HFD at T30 had increases in pro-coagulants fibrinogen (22%), factor VIIc (9%), and factor VIIIc (4%), and decreases in natural anticoagulants antithrombin III (3%), protein C (11%) and protein S (6%) and of 20% in plasminogen activator inhibitor-1. At the same time, individuals on MD had increases in fibrinogen (4%), antithrombin III (5%), protein C (3%), protein S (2.7%), and decreases in factor VIIIc (9%), and plasminogen activator inhibitor-1 (21%). After adjusting by baseline values, MD was associated with lower plasma fibrinogen (P=0.03), factor VIIc (P=0.034) and factor VIIIc (P=0.0057) and with higher levels of protein S (P=0.013). Red wine supplementation, in both diets, resulted in decreased plasma fibrinogen (P=0.001) and factor VIIc (P=0.05), and increased tissue plasminogen activator antigen (P=0.01) and plasminogen activator inhibitor-1 antigen (P=0.0003). Wine consumption was also associated with significantly (P=0.01) divergent effects on antithrombin III: it decreased by 10% in individuals on HFD but increased slightly in those on MD. No effects of diet or wine were detected in plasma protein C and C-reactive protein.

CONCLUSION

MD and moderate consumption of red wine have complementary, mostly beneficial effects on HCVRF.

[Clinical outcome and health related quality of life in patients undergoing coronary angioplasty with balloon or stent. A prospective multicenter study]

INTRODUCTION AND OBJECTIVES

Clinical outcome and health related quality of life after coronary angioplasty with stent or balloon are insufficiently studied in routine practice. The aim of the present study was to assess the impact of angioplasty on the clinical results and quality of life in real clinical practice.

PATIENTS AND METHODS

All the consecutive patients undergoing angioplasty with stent or balloon attending two Spanish tertiary hospitals from October, 1997 to July, 1998 were evaluated at baseline and one year after discharge from hospital with a structured clinical questionnaire and the generic SF-36 quality of life questionnaire.

RESULTS

Three hundred ninety-seven patients with a mean age of 63 years were included in the study. A stent (or stent plus balloon) was implanted in 342 patients and angioplasty with a single balloon was performed in 55 patients. More advanced coronary disease and suboptimal lesions for treatment were found in patients treated with only balloon. At one year of follow up the total mortality was 6% and 54% of the patients were free of angina. Mean baseline scores of the SF-36 questionnaire were remarkably low (35 for physical health and 45 for mental health). At one year the scores achieved levels similar to those of the general Spanish population matched for age and sex (45 for physical health and 52 for mental health). Independent predictors of quality of life at one year were the following: baseline quality of life, age, sex, comorbidity, previous hospitalizations, hospital where the patient was attended, symptoms at admission and late angina.

CONCLUSIONS

a) After percutaneous myocardial revascularization the mean quality of life achieved was similar to that of the general population; b) different clinical subgroups did not achieve these levels, although improvement was similar to that of the remaining subgroups

Allogenic stem cell transplantation as salvage therapy for patients relapsing after autologous transplantation: experience from a single institution

The prognosis of patients relapsing after an autologous transplant (autoSCT) is very poor. Allogenic stem cell transplantation (alloSCT) offers the possibility of curing some of these patients, at the cost, however, of a high transplant related mortality (TRM). The aim of this study was to analyze the outcome of 14 consecutive patients with hematologic malignancies, from a single institution, who underwent alloSCT for progressive disease after autoSCT. Patients had relapsed at a median of 11.5 months (range 2-72) after autoSCT and they underwent alloSCT at a median of 25.5 months (range 7-73) from the first transplant. Ten patients received HLA-identical related peripheral blood progenitor cells, three patients underwent matched-unrelated donor marrow transplants, and one patient received a mismatched related transplant. Conditioning regimens consisted of total body irradiation plus cyclophosphamide (n=5) or melphalan (n=1), or high-dose combination chemotherapy (n=8). Cyclosporin A and methotrexate were administered as graft-versus-host disease (GVHD) prophylaxis. Eight patients (57%) developed grade II-IV acute GVHD. All evaluable patients (n=6) presented extensive chronic GVHD. Overall survival at 1 year was 16% (median 3.5 months, 95% CI 0.7-10.3). Ten patients (71%) died from transplant related complications at a median of 3.5 months (range 0.7-11). Only one patient died of recurrent disease. Three patients remain alive and in complete remission at the time of this report (4, 20 and 20 months, respectively). In conclusion, alloSCT offers the possibility of a sustained control of the disease in some patients who relapse after an autoSCT. However, the procedure is associated with a high transplant-related mortality. Better results might be obtained by carefully selecting patients and by reducing the intensity of the preparative regimen.

MRI and CSF oligoclonal bands after autologous hematopoietic stem cell transplantation in MS

OBJECTIVE

To analyze the MRI and CSF oligoclonal bands (OB) changes in patients with MS who underwent an autologous hematopoietic stem cell transplantation (AHSCT).

BACKGROUND

AHSCT is evaluated as an alternative therapy in severe MS. In previous series of AHSCT for MS, data on MRI or OB outcome were limited or not provided.

METHODS

Five patients with a median Kurtzke's EDSS score of 6.5, more than two attacks, and confirmed worsening of the EDSS in the previous year received an AHSCT. Hematopoietic stem cells were mobilized with cyclophosphamide (3 g/m2) and granulocyte colony-stimulating factor (5 microg/kg/d). The graft was T cell depleted by positive CD 34+ selection. Conditioning regimen included BCNU (300 mg/m(2)), cyclophosphamide (150 mg/kg in 3 days), and antithymocyte globulin (60 mg/kg in 4 days). MRI scans were scheduled at baseline and 1, 3, 6, and 12 months and OB analysis at baseline and 3 and 12 months post-AHSCT.

RESULTS

Four patients had a stable or improved EDSS after a median follow-up of 18 months (range, 12 to 24 months). The fifth patient's condition deteriorated during AHSCT. She partially improved and remained stable after month 3 after AHSCT. The baseline CSF OB persisted 1 year after AHSCT. MRI studies after AHSCT showed no enhanced T1 lesions and no new or enlarging T2 lesions. The median percentage change of T2 lesion load was -11.8% (range, -26.6 to -4.0%). All patients had a decrease of corpus callosum area at 1 year (median, 12.4%; range, 7.8% to 20.5%) that did not progress in the two patients evaluated at 2 years after AHSCT.

CONCLUSIONS

Although the persistence of CSF OB suggests the lymphocytes were not eliminated from the CNS, the follow-up MRI studies showed no enhanced T1 brain lesions and a reduction in the T2 lesion load that correlated with the clinical stabilization of MS after AHSCT.

Binding of recombinant apolipoprotein(a) to human platelets and effect on platelet aggregation

The interaction of lipoprotein(a) [Lp(a)] with platelets is not well defined, particularly with regards to the individual contribution of the protein components of Lp(a), the apo B-100 and the apolipoprotein apo(a). This study investigated the binding of different recombinant apo(a) [r-apo(a)] isoforms, to human platelets and its effect on platelet aggregation. Scatchard analysis of saturation binding experiments demonstrated that human platelets display a single class of high affinity r-apo(a) binding sites (71 +/- 46 molec./platelet, Kd = 5.6 +/- 2.0 nmol/L). Platelet activation with strong agonists (thrombin, arachidonic acid) increased 2- to 10-fold the r-apo(a) binding, without affecting the affinity. Competition assays showed that the binding sites are highly specific for r-apo(a) and Lp(a). At high concentration t-PA could also bind to the r-apo(a) binding sites. By contrast, neither fibrinogen nor plasminogen inhibited to the r-apo(a) binding. The lysine analogue EACA inhibits the binding of r-apo(a) to platelets, thus suggesting the involvement of lysine residues in that interaction. Moreover, the r-apo(a) binding to platelets is unlikely mediated by GPIIb/IIIa-attached fibrin since it is not affected by platelet treatment with either LJ-CP8, a monoclonal antibody that specifically blocks fibrinogen binding to GPIIb/IIIa, nor GPRP, an inhibitor of fibrin polymerisation. Finally, we show that the distinct recombinant apo(a) proteins, as well as native Lp(a), promote an aggregation response of platelets to otherwise subaggregant doses of arachidonic acid. This proaggregant effect of r-apo(a) is dependent on its binding to platelets since it requires a minimum incubation time, and it is prevented by EACA at concentration inhibiting the r-apo(a)-platelet interaction. These results suggest that the prothrombotic action of Lp(a) may be in part mediated by modulating the platelet function through the interaction of its apo(a) subunit with a specific receptor at the platelet surface.

[The effects of dust inhalation in slate industry workers]

BACKGROUND

Slate industries involve the risk of causing silicosis; these industries are now on the increase, which implies an increasing number of workers too. The effects of this type of mining on respiratory health are not yet known.

SUBJECTS AND METHOD

A cross section study of active workers. Radiological and functional alterations, and their relation to risk factors, were assessed.

RESULTS

A prevalence of 2.1% simple pneumoconiosis was found. The value of the FEV1 probed to be significantly related to smoking and to existence of nodulation of a 1/0 or higher profusion; these risk factors, when multiple regression is applied, work independently.

CONCLUSION

Slate industry involves a risk of pneumoconiosis and other respiratory alterations.

CXCR3 chemokine receptor distribution in normal and inflamed tissues: expression on activated lymphocytes, endothelial cells, and dendritic cells

Using new human CXCR3 chemokine receptor-specific monoclonal antibodies, we studied human CXCR3 tissue distribution in lymphoid and nonlymphoid organs, as well as in inflammatory conditions, including rheumatoid arthritis, Hashimoto's thyroiditis, and dermal vasculitis. CXCR3 was expressed by certain dendritic cell subsets, specifically myeloid-derived CD11c positive cells, not only in those present in normal lymphoid organs, but also in germinal centers generated in inflammatory conditions. CXCR3 expression was also detected in some lymphocyte subsets such as intraepithelial lymphocytes of secondary lymphoid organs and infiltrating lymphocytes in inflammatory conditions. In addition, CXCR3 was constitutively expressed by endothelial cells (EC) of vessels of medium and large caliber but not in small vessels from different organs. Finally, enhanced CXCR3 expression was found in EC and in infiltrating lymphocytes with an activated phenotype in inflammatory diseases. The CXCR3 chemokine receptor may play a role in the regulation of leukocyte migration to inflammatory sites.

[Comparative study of 3 tests for susceptibility of Mycobacterium tuberculosis to first-line antituberculous drugs]

Treatment of tuberculosis requires a multidrug regimen for a prolonged period of time (6-12 months), which leads to a high level of noncompliance with therapy. This lack of compliance has led to an increase in drug-resistant strains of Mycobacterium tuberculosis. Rapid drug susceptibility tests are needed to assess effective chemotherapy regimens. In the present study, the reliability of ESP Myco System II(R) and E-test(R) for determining the susceptibility of 82 clinical isolates of M. tuberculosis to rifampin, isoniazid, streptomycin and ethambutol was evaluated by comparing results to those of the multiple proportion method as a reference. ESP Myco System II(R) is a nonradioactive, totally automated, continuously monitored system designed to detect grown mycobacteria. E-test(R) is a well-described method of susceptibility testing which provides data on minimal inhibitory concentration. The susceptibility results of both methods were available within 9 days, while those of the proportion method required 28 days. Levels of agreement between ESP Myco System II(R) and the proportion method for the clinical isolates analyzed were 100% for rifampin, isoniazid and ethambutol. Only one discrepancy was found for streptomycin. For the E-test(R), the results were less favorable. ESP Myco System II(R) was shown to be a rapid and reliable method for testing susceptibility of M. tuberculosis isolates. Nevertheless, E-test(R) provided low specificity for streptomycin and ethambutol. Further studies to test the reliability of the E-test(R) are necessary.

Apoptosis as a scaffold for building up the B cell repertoire

Control of cell number is determined by a balance between cell proliferation and cell death, both of which are highly regulated processes, with numerous checks and balances. Cells control their own death through activation of an internally coded suicide program that, when activated, initiates a characteristic form of cell death called apoptosis. This type of regulation allows elimination of cells that have been produced in excess, that have developed improperly, or that have sustained genetic damage. Apoptosis is, therefore, the most common physiological form of cell death and occurs during embryonic development, tissue remodeling, immune regulation, cell activation and tumor regression.

Involvement of K(ATP) channels in diethylstilbestrol-induced relaxation in rat aorta

The estrogens prevent cardiovascular diseases that among other effects could be related to the modulation of the vascular tone via modifying ionic channel permeability. ATP-sensitive K(+) (K(ATP)) channels seem to be involved in diethylstilbestrol-induced relaxation in isolated rat aorta precontracted by noradrenaline (30 nM), since the effect is inhibited by glibenclamide (1--10 microM), and 1 mM tetraethylammonium, but not by 30 mM tetraethylammonium or paxilline. The antiestrogen tamoxifen, the inhibitor of protein kinase A, Rp-cAMPS, and the inhibitor of ornithine decarboxylase, difluoromethylornithine, antagonized diethylstilbestrol-induced relaxation. The association of glibenclamide with these compounds separately did not modify the effect of glibenclamide alone on diethylstilbestrol-induced relaxation. Functional K(ATP) channels are present in rat aorta, since diazoxide induced relaxation sensitive to glibenclamide. Papaverine, dibutyryl cyclic AMP and spermine relaxed isolated rat aorta although this was not sensitive to glibenclamide. The relaxation to forskolin was antagonized by glibenclamide. We conclude that diethylstilbestrol-induced relaxation in rat aorta is related to the modulation of K(ATP) channels. Cyclic AMP-dependent mechanisms and polyamine synthesis may mediate this modulation.

Inhibition of cytochrome P450 2C9 activity in vitro by 5-hydroxytryptamine and adrenaline

In the present study, the occurrence of a modulatory effect of 14 neurotransmitters, precursors and metabolites on the cytochrome P450 2C9 (CYP2C9) enzyme activity, as determined by diclofenac 4-hydroxylation, was studied in human liver microsomes. Two indoleamines, 5-hydroxytryptamine (5-HT) and adrenaline, showed a non-competitive-type inhibitory effect of approximately 90% of the diclofenac 4-hydroxylase activity, with Ki values of 63.5 (0.7 and 156 (89.3 microM, respectively. The rest of substances analysed were weak inhibitors or had no inhibitory effect. CYP2C subfamily is present in human brain, although CYP2C9 isozyme has not yet been identified in this tissue, and CYP2C9 is involved in the metabolism of psychoactive drugs. Therefore, the fact that endogenous compounds could modulate the CYP2C9 activity, suggests that an hypothetical local activity of brain CYP2C9 might be susceptible to regulatory mechanisms. The possible clinical implications of this modulation are discussed.

Donor age-related differences in PBPC mobilization with rHuG-CSF

BACKGROUND

Data on the administration of rHuG-CSF to normal donors <18 years old are very limited.

STUDY DESIGN AND METHODS

The results of rHuG-CSF administration to 61 donors <18 years old (Group A) were retrospectively evaluated and compared with results from 353 donors > or = 18 years old (Group B) who are included in the Spanish National Donor Registry. The mean age (range) in Group A and B was 14 (1-17) and 38 (18-71) years, respectively (p<0.001). The mean dose of rHuG-CSF was 10 microg per kg per day (range, 9-16) during a mean of 5 days (range, 4-6). Central venous access was placed more frequently in younger donors (25% vs. 6%; p<0.001).

RESULTS

The mean number of CD34+ cells collected was 7.6 and 6.9 x 10(6) per kg of donor's body weight in Group A and B, respectively. Fifty-six percent of Group A donors needed only one apheresis to achieve > or = 4 x 10(6) CD34+ cells per kg versus 39 percent of Group B donors (p = 0.01). Side effects were more common in Group B (71% vs. 41%; p<0.001).

CONCLUSION

The administration of rHuG-CSF to donors <18 years old leads to CD34+ cell mobilization in a pattern similar to that observed in adults. Greater age was associated with a more frequent requirement for more than one apheresis to achieve a similar number of CD34+ cells.