[False resistance to imipenem in gram negative bacilli with and automatized system]

BACKGROUND

The aim of this study was to evaluate the reliability of MIC values of imipenem against gramnegative rods obtained with the automated system WalkAway-98 (MicroScan, Dade, USA).

MATERIAL AND METHODS

One-hundred and seventy three consecutive clinical isolates of Gram-negative rods for which the MIC of imipenem were > or = 4 mg/l (Urine-Combo 6I panels, U6I) or > or = 8 mg/l (Neg-Combo 6I panels, N6I) were evaluated, including 104 non-fermenting gram-negative rods (NFGNR) and 69 enterobacteria. Panels were inoculated and read according to manufacturer's instructions. Microdilution, according to NCCLS guidelines, was used as the method of reference. MIC of imipenem determined by WalllAway-96 and microdilution differing > or = 2 dilution steps from those obtained with mirodilution were considered as discrepant results. Discrepancies in clinical categories were also evaluated by calculating three types of errors: very major (false susceptibility), major (false resistance) and minor (either susceptible or resistant by one method and intermediate by the other one).

RESULTS

The percentages of discrepancies in the MIC of imipenem determined with U6I panels were 74% and 84% for NFGNR and enterobacteria, respectively. No very major errors were detected. Major errors were observed for 6% and 12% of the strains with U6I panels in NFGNR and enterobacteria, respectively, and in 12% (NFGNR) and 50% (enterobacteria) with N61 panels. With U61 panels minor errors were observed in 11% and 25% of NFGNR and enterobacteria, respectively, while with N61 panels minor error were observed in 39% and 45% of both groups, respectively.

CONCLUSIONS

MIC of imipenem > or = 4 mg/l obtained with the WalkAway-96 system against gramnegative rods, particularly in the case of enterobacteria, should be confirmed with a reference susceptibility method.

Glucokinase gene expression is nutritionally regulated in liver of gilthead sea bream (Sparus aurata)

Glucose intolerance in carnivorous fish has been attributed to the lack of hepatic glucokinase (GK) activity. Transcription/translation assay and transient transfection of COS-7 cells with a cDNA encoding Sparus aurata liver GK showed the functionality of the enzyme in vitro. The endogenous fish hepatic GK had lower affinity for glucose than the rat enzyme. The GK activity values in fed fish were similar to those reported for starved and diabetic rats. In this study, we also addressed the nutritional regulation of GK gene expression in fish liver. Starvation and energy restriction decreased S. aurata hepatic GK mRNA and activity levels, as previously reported in rats. In contrast, the fish enzyme expression exhibited a delayed onset during the daily feeding rhythm. These findings demonstrate for the first time the presence and the nutritional modulation of a functional GK activity in fish liver and contribute to explain the low ability of carnivorous fish to metabolize carbohydrates.

Patients with mantle-cell lymphoma relapsing after autologous stem cell transplantation may be rescued by allogeneic transplantation

Two patients with disseminated mantle-cell lymphoma relapsed 24 and 13 months, respectively, after high-dose chemotherapy and autologous stem cell transplantation (autoSCT). Both patients had an HLA-identical sibling and received an allogeneic stem cell transplant (alloSCT) 32 and 18 months after autologous transplant, after conditioning with fractionated 12 Gy total body irradiation plus cyclophosphamide 120 mg/kg. They are both alive and in complete remission 24 months after transplant. Both patients have developed chronic graft-versus-host disease and their Karnofsky performance status is 90%. AlloSCT may offer a useful approach in a subgroup of patients with mantle-cell lymphoma who have relapsed after autologous transplantation.

Fungemia with Saccharomyces cerevisiae in two newborns, only one of whom had been treated with ultra-levura

Ultra-Levura (Upsamedica, Spain) is a yeast (Saccharomyces boulardii) widely used as a biotherapeutic agent. To date, few adverse effects have been reported, although fungemia with Saccharomyces cerevisiae can occur in weak and immunosuppressed patients. Reported here are two cases of fungemia with Saccharomyces cerevisiae. One patient had been treated with Ultra-Levura and the other contracted the infection from the first. This is the first report of infection with Saccharomyces boulardii (Saccharomyces cerevisiae) in a patient who was not being treated with the agent.

Controlled release of cyclosporine from VP-HEMA copolymer systems of adjustable resorption monitorized by MEKC

Soluble, uncrosslinked and high molecular weight copolymers of vinylpyrrolidone, VP, with 2-hydroxyethyl methacrylate, HEMA, prepared by free radical copolymerization, are proposed as supports for the modulated release of drugs, taking cyclosporine as a model system. The copolymerization parameters described as reactivity ratios, rVP = 0.08 and rHEMA = 7.97, indicate that the copolymer systems prepared at high conversion have two main components with a microstructural arrangement which depends on the average composition, i.e., an initial HEMA-rich copolymer and a final PVP homopolymer or VP-rich copolymer. This microstructural distribution controls the resorption rate of the polymeric support and therefore the release process of cyclosporine which is demonstrated experimentally by the application of a modern technique known as micellar electrokinetic capillary chromatography (MEKC).

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene expression is regulated by diet composition and ration size in liver of gilthead sea bream, Sparus aurata

Modulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (6PF-2-K/Fru-2,6-P(2)ase) gene expression by diet composition and ration size was studied in the liver of gilthead sea bream, Sparus aurata. From five different types of diet supplied to fish, those with either high carbohydrate/low protein or high carbohydrate/low lipid content stimulated 6PF-2-K/Fru-2,6-P(2)ase expression at the levels of mRNA, immunodetectable protein and kinase activity as well as promoting higher fructose-2,6-bisphosphate (Fru-2,6-P(2)) values. The expression of the bifunctional enzyme and Fru-2,6-P(2) levels showed also direct dependence on the quantity of diet supplied. These findings demonstrate for the first time nutritional regulation of 6PF-2-K/Fru-2,6-P(2)ase at mRNA level by diet composition and ration size and suggest that the carnivorous fish S. aurata can adapt its metabolism, by stimulation of liver glycolysis, to partial substitution of protein by carbohydrate in the diet. In addition, the expression of 6PF-2-K/Fru-2,6-P(2)ase can be used as an indicator of nutritional condition.

Liver insulin-like growth factor-I mRNA is not affected by diet composition or ration size but shows diurnal variations in regularly-fed gilthead sea bream (Sparus aurata)

Nutritional regulation of insulin-like growth factor-I (IGF-I) mRNA was assessed in liver of gilthead sea bream (Sparus aurata). As in mammals, starvation lowered the IGF-I mRNA content, which was recovered by refeeding. However, in contrast to previous observations in rats, neither diet composition nor ration size significantly affected hepatic IGF-I mRNA. Although fish growth depended on the quantity of diet supplied, no relationship was found between growth and liver IGF-I mRNA levels, a fact that challenges the importance, at least in fish, of liver-derived IGF-I on body growth attributed by the classical somatomedin hypothesis. In addition, diurnal modulation of mRNA levels occurred following food intake, suggesting that the intake of food may play a key role in the regulation of the short-term anabolic effects of IGF-I.

Comparison of several ELISA tests for detecting the presence of IgG and IgM against herpes simplex viruses

Four enzyme-linked immunosorbent assays designated test 1 (ETI-HSVK-G 1/2); test 2 (ETI-HSVK-M 1/2); test 3 (ETI-HSVK-G 2), and test 4 (BioElisa HSV2 IgG) were studied to evaluate different stages of herpes simplex virus (HSV) infection. Samples (50 sera and 14 cerebrospinal fluid) were included in four groups. Group 1 consisted of samples from patients with primary HSV infections; group 2 comprised samples from patients with recurrent HSV infections; group 3 were samples nonreactive to HSV; and group 4 were samples from patients with infections by other herpes viruses (4a, chickenpox; 4b, herpes zoster; and 4c, infectious mononucleosis by Epstein-Barr virus). The percentages of agreement between tests 1 and 2 were 100 and 72.1%, respectively. The total diagnostic values of tests 1 and 2 were: 100 and 50% sensitivity, respectively; and 100 and 89% specificity, respectively. Few positive results for HSV-2 infection were found, and so, tests 3 and 4 were not evaluated. The results of tests 3 and 4 for a chickenpox patient, and a herpes zoster patient were not in agreement.

Immune hemolytic anemia induced by 6-mercaptopurine

BACKGROUND

Myelosuppression is the main hematotoxic effect of 6-mercaptopurine (6-MP), which is an antimetabolite chemotherapy drug. Immune hemolytic anemia associated with this drug has not been previously reported.

CASE REPORT

A 67-year-old man with chronic myelomonocytic leukemia presented with anemia 2 weeks after 6-MP therapy had been initiated. Additional tests provided laboratory evidence of hemolysis. When treatment was stopped, the patient's condition and laboratory results showed a progressive improvement.

RESULTS

The direct antiglobulin test was positive for IgG. The eluate and the serum were not reactive with panel red cells but reacted with 6-MP-treated red cells, while the normal serum pool was unreactive. The direct antiglobulin test was no longer positive by 20 days after the cessation of 6-MP therapy.

CONCLUSION

This drug, 6-MP, should be added to the list of drugs that have been reported to cause immune hemolytic anemia by means of the so-called hapten mechanism.

Synthesis and antiviral activity of carbocyclic nucleosides incorporating a modified cyclopentane ring. Part 3: Adenosine and uridine analogues

Six new carbocyclic nucleosides were prepared by mounting a purine (compounds 4-6), 8-azapurine (7 and 8) or uridine (9) base on the amino group of (1S,3R)-3-amino-2,2,3-trimethylcyclopentylmethanol (10). At subtoxic concentrations, compounds 5-9 showed at best marginal antiviral activity.

Synthesis and antiviral and cytostatic activities of carbocyclic nucleosides incorporating a modified cyclobutane ring. Part 1: Guanosine analogues

Five new carbocyclic nucleosides were prepared by constructing a guanine (compounds 3, 5) or 8-azaguanine (compounds 4, 6, and 7) base on the amino group of (1'S,3'R)-3-(3'-amino-2',2'-dimethylcyclobutyl)propan-1-ol (8), and their activities against a variety of viruses and tumor cell lines were determined. Only compounds 3 and 7 showed a detectable activity at subtoxic concentrations against some viruses tested.

Genetic evidence for the heterodimeric structure of glucosidase II. The effect of disrupting the subunit-encoding genes on glycoprotein folding

It has been proposed that in rat and murine tissues glucosidase II (GII) is formed by two subunits, GIIalpha and GIIbeta, respectively, responsible for the catalytic activity and the retention of the enzyme in the endoplasmic reticulum (ER). To test this proposal we disrupted genes (gls2alpha(+) and gls2beta(+)) encoding GIIalpha and GIIbeta homologs in Schizosaccharomyces pombe. Both mutant cells (gls2alpha and gls2beta) were completely devoid of GII activity in cell-free assays. Nevertheless, N-oligosaccharides formed in intact gls2alpha cells were identified as Glc(2)Man(9)GlcNAc(2) and Glc(2)Man(8)GlcNAc(2), whereas gls2beta cells formed, in addition, small amounts of Glc(1)Man(9)GlcNAc(2). It is suggested that this last compound was formed by GIIalpha transiently present in the ER. Monoglucosylated oligosaccharides facilitated glycoprotein folding in S. pombe as mutants, in which formation of monoglucosylated glycoproteins was completely (gls2alpha) or severely (gls2beta and UDP-Glc:glycoprotein:glucosyltransferase null) diminished, showed ER accumulation of misfolded glycoproteins when grown in the absence of exogenous stress as revealed by (a) induction of binding protein-encoding mRNA and (b) accumulation of glycoproteins bearing ER-specific oligosaccharides. Moreover, the same as in mammalian cell systems, formation of monoglucosylated oligosaccharides decreased the folding rate and increased the folding efficiency of glycoproteins as pulse-chase experiments revealed that carboxypeptidase Y arrived at a higher rate but in decreased amounts to the vacuoles of gls2alpha than to those of wild type cells.

Effect of diet composition and ration size on key enzyme activities of glycolysis-gluconeogenesis, the pentose phosphate pathway and amino acid metabolism in liver of gilthead sea bream (Sparus aurata)

The effects of diet composition and ration size on the activities of key enzymes involved in intermediary metabolism were studied in the liver of gilthead sea bream (Sparus aurata). High-carbohydrate, low-protein diets stimulated 6-phosphofructo 1-kinase (EC 2.7.1.11), pyruvate kinase (EC 2.7.1.40), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) enzyme activities, while they decreased alanine aminotransferase (EC 2.6.1.2) activity. A high degree of correlation was found between food ration size and the activity of the enzymes 6-phosphofructo 1-kinase, pyruvate kinase, glucose-6-phosphate dehydrogenase (positive correlations) and fructose-1,6-bisphosphatase (EC 3.1.3.11) (negative correlation). These correlations matched well with the high correlation also found between ration size and growth rate in starved fish refed for 22 d. Limited feeding (5 g/kg body weight) for 22 d decreased the activities of the key enzymes for glycolysis and lipogenesis, and alanine aminotransferase activity. The findings presented here indicate a high level of metabolic adaptation to both diet type and ration size. In particular, adaptation of enzyme activities to the consumption of a diet with a high carbohydrate level suggests that a carnivorous fish like Sparus aurata can tolerate partial replacement of protein by carbohydrate in the commercial diets supplied in culture. The relationship between enzyme activities, ration size and fish growth indicates that the enzymes quickly respond to dietary manipulations of cultured fish.

Synthesis and antiviral and antineoplastic activities of some novel carbocyclic guanosine analogues with a cyclobutane ring

Cyclobutyl nucleoside analogues containing guanine and 8-azaguanine (compounds 5-10) were prepared from (1R,cis)-3-aminomethyl-2,2-dimethylcyclobutylmethanol (1). All were evaluated as antiviral and antitumoral agents in a variety of assay systems. Compounds 6 and 7 showed a noteworthy activity against a respiratory syncytial virus and compound 10 was moderately active against vaccinia virus. Only compound 5 showed some cytostatic activity.

[Carotid stenosis and lacunar infarct]

INTRODUCTION

Perforating artery disease is still the main cause of lacunar infarcts (LI), while the relationship between this type of ischemia and carotid stenosis (CS) is controversial.

OBJECTIVE

To assess the association between CS and LI in patients with criteria of localized ischemia in the carotid territory separately analyzing isolated LI and multiples LIs.

PATIENTS AND METHODS

Three hundred and thirty patients with a first episode of cerebral infarct in the area supplied by the carotid artery were registered prospectively. There were 205 LI (135 isolated and 70 multiple) which could be differentiated from 125 non-lacunar infarcts (NLI). The vascular risk factors were determined and the degree of carotid stenosis measured by duplex-colour ultrasound exploration.

RESULTS

In the isolated LI group the frequency of presentation of CS greater than 50% was 22% for the artery ipsilateral to the LI and 8% for the contralateral artery. For significant CS (> 70%) frequencies of 14% (ipsilateral) and 8% (contralateral) were observed. On comparative analysis with the NLI group, the presence of stenosis greater than 50 to 70% was significantly higher in these for both ipsilateral and contralateral arteries. In the LI group, isolated CS was significantly more frequent on the side which was homolateral to the ischemia as compared to its isolated presence on the contralateral side (22/30 vs 4/12; OR: 5.5 [95% CI: 1.2-23]). Ipsilateral CS greater than 70% behaved as a factor which was significantly associated with the multiple LI subtype with a unilateral pattern.

CONCLUSION

CS should be considered a risk factor for LI.

In vivo antitumor activity of choline kinase inhibitors: a novel target for anticancer drug discovery

Transformation by some oncogenes is associated with increased activity of choline kinase (ChoK), resulting in elevated constitutive levels of phosphorylcholine, a proposed second messenger required for DNA synthesis induced by growth factors. Here we describe the characterization of ChoK inhibitors with antiproliferative properties against human tumor-derived cell lines. The new molecules were tolerated in mice at doses that showed in vivo antitumor activity against human tumor xenografts derived from HT-29 and A431 cell lines implanted s.c. in nude mice. This first generation of inhibitors provides in vivo evidence that blockade of phosphorylcholine production is a valid strategy for the development of new anticancer agents, opening a new avenue for the development of antitumor drugs with a novel mechanism of action.

New hexahydrocarbazoles and spiro indoles, and their affinity for D2 dopamine and 5-HT2A serotonin receptors

In a search for novel atypical antipsychotics, the synthesis of new hexahydrocarbazoles and spiro indoles N-substituted with a 3-(dimethylamino)propyl chain is described, together with the results of an in vitro evaluation of their affinities for D2 and 5-HT2A receptors.

[Changes in the long arm of chromosome 3 (3q) in malignant myeloid hemopathies. A study of 10 cases]

BACKGROUND

Abnormalities of the long arm of chromosome 3 (3q) involving bands 3q21 and/or 3q26 occur in 2-6% of myeloid malignancies. Trilineage myelodysplasia, especially in the megakaryocytic line, is a characteristic feature. Additional abnormalities of chromosomes 5 and 7 are usually present. The response to treatment and prognosis are poor.

PATIENTS AND METHODS

The main clinical, cytologic (bone marrow aspirate and biopsy) and cytogenetic characteristics as well as the response to the treatment in 10 patients with 3q abnormalities diagnosed in a single hospital in a period of 8 years are referred.

RESULTS

Eight patients had acute non-lymphoblastic leukemia, being de novo in five of them. The median value of hemoglobin was 87 g/l (range: 51-148), white blood cells count 5.8 x 10(9)/l (1.2-47.1) and platelet count 34 x 10(9)/l (5-182). The morphological findings in the study of the bone marrow were: dyserythropoietic features (7 patients), dysgranulopoietic abnormalities (5 patients) and small-sized megakaryocytes with hypolobulated nuclei (8 patients). Fibrosis was observed in the 4 cases in which a bone marrow biopsy was performed. In addition to the 3q alteration, abnormalities of chromosomes 7 (4 patients), 5q (2 patients) and +8 (2 patients) were present. Four patients received intensive chemotherapy and in two of them a complete remission was achieved, but relapse occurred at 3 and 5 months, respectively. All patients have died, the median survival being 7 months.

CONCLUSIONS

3q abnormalities define a subtype of myeloid malignancies with characteristic clinical and morphological features. The response to therapy and survival are poor.