Adenosine A1 receptor agonist treatment up-regulates rat brain metabotropic glutamate receptors

Chronic R-N(6)-phenylisopropiladenosine (R-PIA) subcutaneous injection for 6 days significantly increased total glutamate receptor number (180% of control) in rat brain synaptic plasma membranes (SPM), without affecting receptor affinity. A higher increase in metabotropic glutamate (mGlu) receptor number (258% of control) was also detected, indicating that mGlu is the main type of glutamate receptor affected by this treatment. On the other hand, the observed increase in basal and calcium- and Gpp(NH)p-stimulated phospholipase C (PLC) activity after treatment was associated with a significant increase in PLC beta(1) isoform, detected in SPM by immunoblotting assays. Moreover, an increase in PLC activity stimulation with trans-ACPD, in the absence and in the presence of Gpp(NH)p, was detected after R-PIA treatment. These results show that mGlu receptors and its effector system, PLC activity, are up-regulated by chronic exposure to an adenosine A(1) receptor agonist and suggest the existence of a cross-talk mechanism between both signal transduction pathways in rat brain.

Acrylic-phosphate glasses composites as self-curing controlled delivery systems of antibiotics

New antibiotic delivery systems based on self-hardening methyl methacrylate (MMA)/polymethyl methacrylate (PMMA) systems and phosphate glasses (PG) in the system P(2)O(5)-CaO-Na(2)O have been developed. Self-curing formulations were prepared by mixing the solid component containing PMMA beads, different proportions of PG (30-70 wt %) and vancomycin (5 wt %) as antibiotic, with the liquid component made of MMA monomer. Dough and setting times increased with the content of PG but peak temperature decreased to values well below to guarantee the chemical stability of the antibiotic drug, gentamicin or vancomycin. Mechanical properties of the PMMA/PG composites were evaluated in compression test giving rise to values of compressive strength in the range of 100 MPa. The release of vancomycin was analyzed in vitro by immersion of samples in phosphate buffer of pH=7.4. Release profiles were influenced by the content of PG present in the cement. An initial burst of drug release was observed in all cases. The composites with 70 wt % PG released nearly the total amount of drug loaded in a period of 45 days, and those containing 60 wt % PG released the 70% of the vancomycin in the same period of time. However, either the control of the composite with 30 wt % PG released only the 30% of the drug in 10-15 days. The surface of the drug-loaded composites before and after release experiments was analyzed by ESEM. The deposition of some aggregates at certain points of the surface was detected for the specimens immersed in buffer phosphate after 45 days. This material was characterized by FTIR and Raman spectroscopy as an amorphous phosphate formed by calcium ortho and pyrophosphates, and indicates an interaction between the hydrated layer at the place of the glass and the surrounding medium.

[Comparative study of prognostic and risk factors for mortality in polymicrobial bacteremia-fungemia in a university hospital: development over 10 years]

OBJECTIVE

Eighty-two episodes of polymicrobial bacteremia in two time periods, 1986-87 and 1996-97, were compared to assess differences in risk factors and outcome to mortality.

METHODS

A prospective, concurrent, anterograde study with univariate analysis of all episodes of polymicrobial bacteremia was performed in Hospital de la Princesa. Logistic regression analysis was applied to all significant variables (p < 0.05) in the univariate analysis in either of the two time periods.

RESULTS

Variables showing statistically significant differences in incidence between the two time periods included the following: hospital acquired bacteremia; previous use of antibiotics; genitourinary, respiratory and cardiovascular manipulations; septic metastases; and absence of leukocytosis. These factors were more frequently present during 1986-87 than during 1996-97. The overall RR of outcome to mortality was five-fold greater during the first period than the second: RR 5.6 (CI 1.76-17.56) p < 0.001. The clinical characteristics at the onset of bacteremia associated with mortality in the first period were: underlying disease - < RR 2.20 (CI 1.18-4.08), steroid treatment - < RR 4.24 (CI 0.68-26.59), hypotension - < RR 2.05 (CI 1.0-4.17), and disseminated intravascular coagulation - < RR 2.31 (CI 1.69-3.35). Clinical characteristics at the onset of bacteremia associated with mortality in the second period were: hypotension - < RR 1.44 (CI 1.01-2.08), underlying disease - < RR 1.16 (CI 1.02-1.34), and disseminated intravascular coagulation - < RR 6.40 (CI 1.15-35.69). The variables independently associated with mortality in polymicrobial bacteremia were: period - < RR 2.05 (CI 1.50-2.10), underlying disease - < RR 7.05 (CI 2.68-7.50), hypotension - < RR 7.06 (CI 3.80-7.29), and (probably) vascular manipulations - < RR 3.41 (CI 0.85-4.53).

CONCLUSION

Polymicrobial bacteremia-associated mortality was five-fold greater in 1986-87 than in 1996-97. The variables independently associated with mortality risk were underlying disease, hypotension, the period studied (which would include a number of variables not analyzed in this work) and, probably, vascular manipulations.

Analytical methods for pesticide residue determination in bee products

Monitoring pesticide residues in honey, wax, and bees helps to assess the potential risk of these products to consumer health and gives information on the pesticide treatments that have been used on the field crops surrounding the hives. The present review seeks to discuss the basic principles and recent developments in pesticide analysis in bee products and their application in monitoring programs. Consideration is given to extraction, cleanup, chromatographic separation, and detection techniques.

Duration of increased serum alkaline phosphatase activity in dogs receiving different glucocorticoid doses

Exposure to exogenous glucocorticoids can variably increase the serum alkaline phosphatase (alp) activity, however, the duration of this effect in dogs has not been determined. In this study, three groups of ten clinically normal adult dogs were administered different types of glucocorticoids at therapeutic doses. Group 1 received prednisone 1 mg kg day(-1)p.o. for 3 weeks; Group 2 received a single dose of methylprednisone acetate 1.1 mg kg day(-1)s.c.; Group 3 received dexamethasone 0.25 mg kg day(-1)p.o. for 1 week. In Group 1 elevations were statistically significant on days 7, 14 and 21 (P<0.01, P<0.001, P<0.001, respectively). After discontinuing therapy serum alp returned to baseline levels in 7 days. In Group 2, serum alp activity remained significantly elevated for 3 weeks after therapy (P<0.05, P<0.001, P<0.01 on days 7, 14 and 21 respectively). In Group 3, serum alp levels were significantly increased after 1 week of therapy (P<0.001) returning to basal levels 2 weeks after discontinuing glucocorticoid administration. In conclusion, duration of increased serum alp activity was variable and with the protocols assessed a 3-week period for short-acting glucocorticoids and more than 4 weeks for long-acting methylprednisone may be required to return to baseline levels in all dogs.

Basement membrane and connective tissue proteins in intestinal mucosa of patients with coeliac disease

AIMS

Gluten ingestion in coeliac disease is associated with alterations of the intestinal mucosa, especially the expansion of the lamina propria. Antiendomysium and antireticulin antibodies may result from interactions between gliadin and extracellular matrix components. By behaving as autoantigens, connective tissue proteins could initiate mucosal damage. This study evaluates changes in the distribution of laminin, type IV collagen, and fibronectin in the mucosa of patients with coeliac disease in an attempt to explain the alterations of mucosal morphology.

METHODS

Intestinal biopsies were obtained from patients with coeliac disease on admission and while on a gluten free diet. The distribution of type IV collagen, laminin, fibronectin, and alpha-smooth muscle actin was evaluated by immunofluorescence and by immunogold labelling and electron microscopy.

RESULTS

In patients with coeliac disease, the intensity of type IV collagen, laminin, and fibronectin immunofluorescent staining was decreased and less well defined than in controls, with frequent breaches in the basement membrane; fibronectin staining was weak in the distal third of the elongated crypts and absent under the flat surface. The distribution of smooth muscle fibre in the distal lamina propria of flat mucosae was altered. The distribution of these proteins was normal as assessed by immunoelectron microscopy.

CONCLUSIONS

The intensity of staining of some components of the basement membrane is decreased in coeliac disease and the distribution of smooth muscle fibres is altered. These changes may result from interactions between gliadin and components of the extracellular matrix and may play a role in the genesis of mucosal lesions and in the damage to the epithelium.

Prospective, randomised study with three HRT regimens in postmenopausal women with an intact uterus

OBJECTIVE

To compare compliance, symptom control, bleeding patterns, lipid and biochemical changes in postmenopausal women treated with three regimens of HRT.

METHODS

In a prospective, randomised, group comparative study, with 165 patients, the effects on the aforementioned parameters, as well as treatment compliance and side effects were studied with oral tibolone 2.5 mg per day, with cyclic combined regimen of transdermal oestrogen and progestogen (transdermal patch of 17beta-oestradiol 50 microg/day during 14 days and transdermal patch of 17beta-oestradiol 50 microg/day plus 0.25 mg/day NETA during the following 14 days), and with intermittent progesterone regimen (transdermal 17beta-oestradiol 50 microg/day and oral micronised natural progesterone 200 mg twice a week). Statistical analysis was carried out using the Fisher-test, analysis of the variance (ANOVA) and the Bouferoni test.

RESULTS

Ten women dropped out of the tibolone group, 11 dropped out of the intermittent dosing group and 21 dropped out of the cyclid combined group. Irregular bleeding occurred at more rates in the cyclid combined group. Similar reductions in climacteric symptoms were found in the three groups. No differences were observed with respect to biochemical analysis.

CONCLUSIONS

Efficacy and safety of the three treatment regimens being comparable, but the patients in our study preferred those that did not produce bleeding episodes.

Long-term outcome of patients with asystole induced by head-up tilt test

AIMS

To analyse the long-term outcome of the largest reported cohort of patients presenting asystole during head-up tilt test.

METHODS AND RESULTS

Since 1990, 1322 patients with syncope of unknown origin have undergone tilt-table testing. Of those, 330 patients (24 X 9%) presented an abnormal response (syncope or pre-syncope). Furthermore, 58 of those patients (17 X 5%) suffered a period of asystole (> or = 3000 ms) during the test. Asystole (median (interquartile range)) lasted 10 (4, 19 X 2) s (range 3-90). Two different protocols (angles) of tilting (Westminster (60 degrees) n=1124; isoproterenol (80 degrees) n=198)) influenced the time to the syncopal episode (13 (6 X 5, 20 X 5) vs 2 (1, 6 X 5) min, P=0,0005) but not the duration of the asystole. During this period, therapy for asystole featured three different stages: first patients were treated with pacemakers; later drug therapy (metoprolol and/or etilefrine) was recommended; lastly (from 1995), no specific treatment was given. In a cohort age- and gender-matched study, those patients without were compared to those with asystole in a 2:1 basis. During 40 X 7 months of follow-up (17 X 7, 66 X 8), 12 patients (20 X 6%) with asystole had syncopal recurrences. Furthermore, 34 patients (28 X 8%) without asystole presented syncopal episodes during a follow-up of 51 X 6 months (29 X 3, 73 X 1) (P=ns). The Kaplan-Meier analysis in patients with and without asystole showed a mean time free of recurrence of 92 X 6 +/- 6 months vs 82 X 6 +/- 4 X 7 months (P=ns). The previous number of syncopes had a significant relationship with recurrences (P=0 X 002), but not therapy. There were no cardiac related deaths.

CONCLUSIONS

(1) Asystole during head-up tilt test does not imply a malignant outcome and syncope recurrence is low; (2) pacemaker or drug therapy do not significantly influence outcome which correlates to the previous number of syncopal episodes but not to gender, age, asystole occurrence, asystole duration and timing to asystole during head-up tilt test; (3) tilting protocol (angle) might influence time to and incidence of asystole during head-up tilt test.

Small-angle x-ray scattering studies of human breast tissue samples

Small-angle x-ray scattering (SAXS) patterns are recorded from thin breast tissue samples containing healthy and cancerous regions. The SAXS patterns are compared with histo-pathological observations. The information available from SAXS is reviewed, and a model for scattering from collagen is presented. Scattering patterns of collagen at regions far from the tumours are essentially different from those at tumours. The axial period of collagen fibrils is 65.0 +/- 0.1 nm in healthy regions, and 0.3 nm larger in cancer-invaded regions. The average intensity of scattering from cancerous regions is an order of magnitude higher than the intensity from healthy regions. This is interpreted to arise from an increase of the specific surface area of the scatterers, which is due to a disruption of the molecular and supra-molecular structures in cancerous regions and invasion of new types of cells. The differences of the SAXS patterns are large and distinctive enough to suggest that these phenomena may be utilized in mammography.

[The role of connective tissue in the morphology and function of intestinal mucosa. Its participation in the pathogenesis of celiac diseases]

The differentiation, architecture and function of the mucosa of the digestive tract is the result of close interactions between the epithelial cells and their underlying connective tissue. This interaction not only plays a role in the normal morphological organization of the intestinal mucosa but also in the organization and maturation of the enterocytes, the development of some of their enzymatic activities, the transport of nutrients and the restitution of the epithelium following denudation of the surface of villi due to loss of enterocytes. It is thought that disturbances of the cells of the connective tissue, especially of the myofibroblasts as well as of some of the above mentioned mechanisms, participate in the pathogenesis of some gastrointestinal diseases, celiac disease among them. This review summarizes some of the knowledge in this area.

Intrahepatic hepatitis C virus replication is increased in patients with regular alcohol consumption

AIMS

To assess clinical significance of liver hepatitis C virus RNA levels and their relationship with epidemiological, biochemical and histological factors.

METHODS

A total of 50 patients (mean age 35.5+/-7 years) with biopsy-proven chronic hepatitis C infection were recruited. Risk factors were drug abuse (n=21), transfusion (n=16), other parental routes (n=8; surgery=3, tattooing=5), and idiopathic (n=5). Duration of infection was 16+/-9 years. All patients showed abnormal alanine aminotransferase levels and positive serum hepatitis C virus RNA. Hepatitis C virus genotype was assessed by Inno-Lipa. Liver biopsy was performed for histology and for hepatitis C virus RNA quantification by Amplicor-HCV-Monitor Daily alcohol consumption was recorded on two occasions by anamnesis. Inflammation grade was mild (n=31) or severe (n=19). Fibrosis was early stage (n=42) or advanced (n=8).

RESULTS

Mean hepatitis C virus RNA levels were 9.4x10(5)+/-1.5x10(6) copies/microg of total RNA in liver tissue, and 9.1x10(5)+/-1.3x10(6) copies/ml in serum. Viral load in liver was positively correlated with that in serum (r=0.51, p<0.001) and there was a significant relationship between daily alcohol consumption and intrahepatic hepatitis C virus burden (r=0.53; p<0.001). Patients infected with genotype 3a showed lower intrahepatic hepatitis C virus load than patients infected with genotype 1b; albeit without reaching statistical significance (0.49x10(6)+/-0.89x10(6) vs 1.44x10(6)+/-1.9x10(6) copies/microg of total RNA; p=NS). No relationships were observed between liver viral burden and age, risk factor status, duration of infection, ferritin and alanine aminotransferase levels or with grading and staging.

CONCLUSIONS

Hepatitis C virus load in serum is a mirror of intrahepatic hepatitis C virus levels. Chronic alcohol consumption enhances intrahepatic hepatitis C virus concentration.

Involvement of VIP on BDNF-induced somatostatin gene expression in cultured fetal rat cerebral cortical cells

Previous studies have shown that BDNF promotes expression of SS. In earlier studies we demonstrated the stimulatory effect of locally produced VIP upon SS secretion. These facts led us to explore the peptidergic action of BDNF on VIP, and to determine if BDNF-induced SS might be mediated by the induction of VIP. Cultured fetal rat cerebrocortical cells were incubated with BDNF (50 ng/ml) and/or VIP (10(-11) M) for 2 and 5 days. In other experiments IgGs from BDNF or VIP antisera were also added. BDNF increased VIP and SS gene expression and peptide production. After 2 days of incubation with both BDNF and VIP the induction of SS mRNA was similar to that obtained with BDNF alone. However when the treatment was extended to 5 days the increase in SS mRNA was higher than that obtained with BDNF alone. This finding suggests the possibility that both factors acted synergistically. To define the potential role of VIP in the response of SS gene expression to BDNF, endogenous VIP was blocked with IgGs from VIP antiserum. Under these experimental conditions BDNF-induced SS decreased. Our study provides the first evidence that BDNF up-regulates VIP gene expression and concentration of the peptide. The involvement of VIP on BDNF-induced SS gene expression is also demonstrated.

[Compliance of antituberculosis therapy among ex-inmates in the Madrid area]

BACKGROUND

The inmate population is not a tight compartment without communication with the community but there is a flow of persons and thus of health problems. The high incidence of tuberculosis among inmates is therefore of concern for the Public Health System.

METHODS

The outcomes of antituberculosis treatment among ex-inmates released from prison in 1987 in the Madrid Area were evaluated and compared with those who remained in jail on treatment. Individuals who met the case definition of tuberculosis were included in the study. The outcome was defined as the individual status one year after the beginning of therapy. To determine the association between the study variables with outcome, odds ratios (OR) with their 95% confidence intervals were used. The Chi2 test was used to determine the statistical significance.

RESULTS

Differences between outcomes of individuals in the two groups were observed: 69.7% of inmates had completed their therapy compared with 20.5% of ex-inmates. Treatment had to be prolonged in 15.2% of inmates compared with 46.2% in ex-inmates. The only predictor associated with therapy completion one year after the beginning was imprisonment, as OR for not having completed therapy for ex-inmates was almost 13 times higher (OR=12.94; 95% IC, 3.38-13.10) than those in jail.

CONCLUSIONS

Special strategies should be developed that assure clinical cure of persons with factors related to non-compliance.

[Coronary reoperation: a 16 years retrospective analysis]

BACKGROUND

Coronary artery bypass grafting (CABG) reoperation is being performed with increasing frequency.

AIM

To assess the early and long term results of coronary reoperations in our institution and to identify prognostic factors.

PATIENTS AND METHODS

214 patients subjected to coronary reoperations between 1983 and 1999 were retrospectively studied.

RESULTS

Mean age was 64.2 years (range 42-79 years), 202 (94.4%) were male and 12 (5.6%) female. The mean interval between the operations was 125.7 months (range 6-252 months). 10 (4.6%) were emergency surgeries. Overall operative mortality was 5.6% (11 deaths) and in 5 patients (3.4%) a perioperative myocardial infarction was noted. Univariate analysis identified moderate or severe left ventricular failure (p = 0.048) as predictor of increased operative mortality, meanwhile age over 75 years (p = 0.02) and moderate or severe left ventricular failure (p = 0.01) were identified as predictors of increased in hospital mortality in the multivariate analysis. Follow up of in hospital survivors (mean interval 65 months, range 4 to 190 months) documented a 5 years survival rate of 82.9%, a 10 years survival rate of 73.1% and a 15 years survival rate of 53.4%. Moderate or severe left ventricular failure (p < 0.0001) and emergency surgeries (p = 0.007) were identified as factors influencing the late survival in the stepwise logistical regression analysis. Multivariate analysis identified left ventricular failure (p = 0.01) and peripheral vascular disease (p = 0.01) as predictors of decreased late survival.

CONCLUSIONS

Coronary reoperation has a low mortality in patients with a normal ventricular function and also has an excellent overall and disease free survival in the first 10 years of follow up. Left ventricular function is an independent risk factor increasing in hospital and late mortality.

Activation of caspases occurs downstream from radical oxygen species production, Bcl-xL down-regulation, and early cytochrome C release in apoptosis induced by transforming growth factor beta in rat fetal hepatocytes

Most of the morphologic changes that are observed in apoptotic cells are caused by a set of cysteine proteases (caspases) that are activated during this process. In previous works from our group we found that treatment of rat fetal hepatocytes with transforming growth factor beta1 (TGF-beta1) is followed by apoptotic cell death. TGF-beta1 mediates radical oxygen species (ROS) production that precedes bcl-xL down-regulation, loss of mitochondrial transmembrane potential, release of cytochrome c, and activation of caspase-3 (Herrera et al., FASEB J 2001;15:741-751). In this work, we have analyzed how TGF-beta1 activates the caspase cascade and whether or not caspase activation precedes the oxidative stress induced by this factor. Our results show that TGF-beta1 activates at least caspase-3, -8, and -9 in rat fetal hepatocytes, which are not required for ROS production, glutathione depletion, bcl-xL down-regulation, and initial cytochrome c release. However, caspase activation mediates cleavage of Bid and Bcl-xL that could originate an amplification loop on the mitochondrial events. An interesting result is that transmembrane potential disruption occurs later than the initial cytochrome c release and is mostly blocked by the pan-caspase inhibitor Z-VAD.fmk, indicating that the decrease in mitochondrial transmembrane potential (Delta(Psi)m) may be a consequence of caspase activity rather than the mechanism by which TGF-beta induces cytochrome c efflux. Finally, although Z-VAD.fmk completely blocks nucleosomal DNA fragmentation, it only delays cell death, which suggests that activation of the apoptotic program by TGF-beta in fetal hepatocytes inevitably leads to death, with or without caspases.

[Intestinal parasitic infections in 4 child day-care centers located in San Miguel del Padrón municipality, Havana City, 1998]

A coproparasitologic study was performed on 456 children aged 1-5 years from 4 day-care centers located in San Miguel del Padrón municipality during November 1998, with the aim of finding out the behaviour of the main intestinal parasites and particularly how Giardia lamblia was affecting this child population. Three fecal specimens were collected from each child in every other day, which were processed by coproparasitologic methods such as direct testing and Ritchie's concentration technique. The most frequently identified parasite was G. lamblia with 249 positive cases for a prevalence rate of 54.6%. The second one was Blastocystis hominis (29.6%) followed by Endolimax nana(23.9%). Coccidia like Crystosporidium parvum and Cyclospora cayetanensis exhibited low frequencies, 0.6 and 1.5% respectively, being the majority of the cases located in only one day care center. These results confirmed that G. lamblia is the most prevailing parasite in day care centers, with peak frequency values in 2-4y age group and no differences between sexes.

Favourable effect of the combination of acute and chronic graft-versus-host disease on the outcome of allogeneic peripheral blood stem cell transplantation for advanced haematological malignancies

To assess the influence of graft-versus-host disease (GVHD) on the outcome of patients with advanced haematological malignancies (AHM) who received a primary, unmodified allogeneic peripheral blood progenitor cells transplant (allo-PBT) from a human leucocyte antigen (HLA) identical sibling donor, we analysed 136 patients with myeloid neoplasms (n = 70) or lymphoproliferative disorders (n = 66), transplanted at 19 Spanish institutions. Median age was 35 years (range 1-61). The cumulative incidence of relapse for all patients was 34% (95% CI, 26-42%), 41% (95% CI, 33-49) for patients without GVHD and 14% (95% CI, 3-25) (P = 0.001) for patients with acute and chronic GVHD. After a median follow-up of 11 months (range 2-49), 60 (44%) patients remained alive with an actuarial probability of overall survival and disease-free survival (DFS) at 30 months of 31% (95% CI, 21-41%) and 28% (95% CI, 17-39%) respectively. In patients surviving > 100 d, the low incidence of relapse in those with acute and chronic GVHD led to a DFS of 57% (95% CI, 38-76%) compared with a DFS of 34% (95% CI, 17-51%) in the remaining patients (P = 0.03). Our results indicate a reduced incidence of relapse for patients with AHM receiving an unmodified allo-PBT and developing acute and chronic GVHD, which results in an improved DFS.