Nephrotoxicity of concomitant use of tacrolimus and teicoplanin in allogeneic hematopoietic stem cell transplant recipients

Both tacrolimus and glycopeptide antibiotics are known to be nephrotoxic, and are often concomitantly given after hematopoietic stem cell transplantation (HSCT) or solid organ transplantation. The aim of this study is to evaluate the nephrotoxicity of concomitant use of tacrolimus and glycopeptide antibiotics in HSCT recipients. We retrospectively evaluated 67 patients who received intravenous tacrolimus and teicoplanin concomitantly for >4 days after allogeneic HSCT for hematologic diseases. Therapeutic drug monitoring (TDM) was performed in all patients for both tacrolimus and teicoplanin. The median age of the patients was 48 years (range: 16-62), and the median duration of the co-administration of tacrolimus and teicoplanin was 11 days (range: 4-40). The mean serum creatinine (sCr) level tended to be elevated after the co-administration (from 0.69 ± 0.26 to 0.75 ± 0.30 mg/dL; P = 0.08); however, a 2-fold or greater increase in sCr was observed only in 2 (3.0%) patients. Increased sCr was reversible, and no patient required hemodialysis. These results suggest that the incidence of clinically significant nephrotoxicity can be minimized if the TDM of each drug is properly applied.

Mycobacterium avium genotype is associated with the therapeutic response to lung infection

Factors that can interfere with the successful treatment of Mycobacterium avium lung infection have been inadequately studied. To identify a potent predictor of therapeutic responses of M. avium lung infection, we analyzed variable number tandem repeats (VNTR) at 16 minisatellite loci of M. avium clinical isolates. Associations between the VNTR profiling data and a therapeutic response were evaluated in 59 subjects with M. avium lung infection. M. avium lung infection of 30 subjects in whom clarithromycin-containing regimens produced microbiological and radiographic improvement was defined as responsive disease, while that of the remaining 29 subjects was defined as refractory disease. In phylogenetic analysis using the genotypic distance aggregated from 16-dimensional VNTR data, 59 M. avium isolates were divided into three clusters, which showed a nearly significant association with therapeutic responses (p 0.06). We then subjected the raw 16-dimensional VNTR data directly to principal component analysis, and identified the genetic features that were significantly associated with the therapeutic response (p <0.05). By further analysis of logistic regression with a stepwise variable-selection, we constructed the highest likelihood multivariate model, adjusted for age, to predict a therapeutic response, using VNTR data from only four minisatellite loci. In conclusion, we identified four mycobacterial minisatellite loci that together were associated with the therapeutic response of M. avium lung infections.

Lipopolysaccharide of Aggregatibacter actinomycetemcomitans up-regulates inflammatory cytokines, prostaglandin E2 synthesis and osteoclast formation in interleukin-1 receptor antagonist-deficient mice

BACKGROUND AND OBJECTIVE

The interleukin (IL)-1 receptor antagonist (Ra) binds to IL-1 receptors and inhibits IL-1 activity. However, it is unclear whether the IL-1Ra plays a protective role in periodontal disease. The purpose of this study was to compare IL-1Ra knockout (KO) and wild-type (WT) mice in regard to proinflammatory cytokine production, osteoclast formation and bone resorption in response to periodontal bacterial lipopolysaccharide (LPS).

MATERIAL AND METHODS

Peritoneal macrophages (Mφs) were obtained from 13-wk-old IL-1Ra KO and WT mice. Peritoneal Mφs were cultured with or without 10 μg/mL of Aggregatibacter actinomycetemcomitans LPS for 24 h. The levels of IL-1alpha (IL-1α), IL-1beta (IL-1β), tumor necrosis factor-α (TNF-α) and IL-6 were measured in periotoneal Mφs supernatant fluid (PM-SF) using an ELISA. Bone marrow cells were obtained from the mice and stimulated with PM-SF for 9 d, then stained with TRAP. The frequency of TRAP-positive multinucleated giant cell formation was calculated based on a fusion index. PM-SF-stimulated calvarial bone resorption was analyzed using micro-computed tomography, and calvarial histological analysis was performed using hematoxylin and eosin and TRAP staining. The expression of cyclooxygenase-2 (Cox2), prostanoid receptor EP4 (Ep4) and Rank mRNAs in bone marrow cells were measured using real-time quantitative PCR, while prostaglandin E2 (PGE2 ) production was determined by ELISA.

RESULTS

The levels of IL-1α, IL-1β, TNF-α and IL-6 in IL-1Ra KO mice PM-SF stimulated with A. actinomycetemcomitans LPS were significantly increased by approximately 4- (p < 0.05), 5- (p < 0.05), 1.3- (p < 0.05) and 6- (p < 0.05) fold, respectively, compared with the levels in WT mice. Moreover, osteoclast formation, expression of Rank, Ep4 and Cox2 mRNAs and production of PGE2 were significantly increased by approximately 2- (p < 0.05), 1.6- (p < 0.05), 2.5- (p < 0.05), 1.6- (p < 0.05) and 1.9- (p < 0.05) fold, respectively, in IL-1Ra KO mice stimulated with A. actinomycetemcomitans LPS compared with WT mice.

CONCLUSION

IL-1Ra regulates IL-1 activity and appears to reduce the levels of other inflammatory cytokines, including TNF-α and IL-6, while it also reduces expression of the EP4 receptor related to prostanoid sensitivity and osteoclast formation. These results suggest that IL-1Ra is an important molecule for inhibition of inflammatory periodontal bone resorption.

Favourable outcome of progressive multifocal leukoencephalopathy with mefloquine treatment in combination with antiretroviral therapy in an HIV-infected patient

A 33-year-old man who developed progressive multifocal leukoencephalopathy (PML) with HIV infection is reported. The patient exhibited rapid decline in neurological status after initiation of antiretroviral therapy (ART), which was attributed to the PML-immune re-constitution inflammatory syndrome. Following the administration of mefloquine in combination with ART, the patient's neurological status improved substantially. This case suggests that further investigation of the use of mefloquine might be warranted for treatment of PML in HIV-infected patients.

Cytotoxicity of size-density fractionated coal fly ash in rat alveolar macrophages cultured in vitro

The cytotoxicity of coal fly ash particles was investigated in rat alveolar macrophages cultured in vitro. Fly ash particles of a similar diameter (1-5 mum) were selected and then separated into five groups with respect to density (i.e. <1.6, 1.6-2.0, 2.0-2.4, 2.4-2.8 and >2.8 g/cm(3)). The exclusion of trypan blue and the extracellular release of lactate dehydrogenase were used as indicators of cell viability. The fraction of fly ash particles with the highest density (>2.8 g/m(3)) was most cytotoxic. The degree of cytotoxicity appeared to be correlated with the amount of particles taken up by macrophages as well as with their heavy metal concentrations. Morphological observation of the surface of the macrophages by scanning electron microscopy revealed a decrease in the number of filopodia and microvilli and an enhancement of the ruffled membrane. These morphological changes became more obvious with increasing concentrations of fly ash particles, but there was no characteristic change specific to each fraction of fly ash.

Diurnal variation in neutrophil function

Neutrophil functions, including chemotaxis, reactive oxygen species (ROS)-producing capacity of neutrophils, and serum opsonic activity were investigated in 9 young healthy male volunteers. Venous blood of these volunteers was obtained under standardized conditions at 4-h intervals over a 24-h span. Neutrophil chemotaxis was evaluated by a modified Boyden technique, ROS-producing capacity of neutrophils and serum opsonic activity were measured by a simultaneous multiple measurement system based on luminol-dependent chemiluminescence and indicated by peak height and peak time. ROS-producing capacity of neutrophils and serum opsonic activity were activated in the daytime, and decreased from night to morning. There were negative correlations between the peak time of the luminol-dependent chemiluminescent response, neutrophil number (p<0.01) and segmented neutrophil number (p>0.01). On the other hand, no significant correlations were noted between serum opsonic activity and IgG, IgA, IgM, C3 or C4. In contrast, the peaks of neutrophil chemotaxis were at the wake-up time (6:00a.m.) and in the evening (6:00p.m.). This study indicates that diurnal variation of neutrophil function exists.

Phylogenetic study of the species within the family Streptomycetaceae

Species of the genus Streptomyces, which constitute the vast majority of taxa within the family Streptomycetaceae, are a predominant component of the microbial population in soils throughout the world and have been the subject of extensive isolation and screening efforts over the years because they are a major source of commercially and medically important secondary metabolites. Taxonomic characterization of Streptomyces strains has been a challenge due to the large number of described species, greater than any other microbial genus, resulting from academic and industrial activities. The methods used for characterization have evolved through several phases over the years from those based largely on morphological observations, to subsequent classifications based on numerical taxonomic analyses of standardized sets of phenotypic characters and, most recently, to the use of molecular phylogenetic analyses of gene sequences. The present phylogenetic study examines almost all described species (615 taxa) within the family Streptomycetaceae based on 16S rRNA gene sequences and illustrates the species diversity within this family, which is observed to contain 130 statistically supported clades, as well as many unsupported and single member clusters. Many of the observed clades are consistent with earlier morphological and numerical taxonomic studies, but it is apparent that insufficient variation is present in the 16S rRNA gene sequence within the species of this family to permit bootstrap-supported resolution of relationships between many of the individual clusters.

Sulfate complexation of element 104, Rf, in H2SO4/HNO3 mixed solution

The cation-exchange behavior of 261Rf (T 1/2= 78 s) produced in the 248Cm(18O, 5n) reaction was studied on a “one-atom-at-a-time” scale in 0.15–0.69 M H2SO4/HNO3 mixed solutions ([H+]=1.0 M) using an automated ion-exchange separation apparatus coupled with the detection system for alpha-spectroscopy (AIDA). It was found that adsorption probabilities ( decrease with an increase of [HSO4 −], showing a successive formation of Rf sulfate complexes. Rf exhibits a weaker complex formation tendency compared to the lighter homologues Zr and Hf. This is in good agreement with theoretical predictions including relativistic effects.

Fine mapping of porcine SSC14 QTL and SCD gene effects on fatty acid composition and melting point of fat in a Duroc purebred population

The stearoyl-CoA desaturase (delta-9-desaturase; SCD) gene is a candidate gene for fatty acid composition. It is located on pig SSC14 in a region where quantitative trait loci (QTL) for fatty acid composition were previously detected in a Duroc purebred population. The objective of the present study was to fine map the QTL, to identify polymorphisms of the pig SCD gene and to examine the effects of SCD polymorphisms on fatty acid composition and melting point of fat in the population. The pigs were examined for fatty acid composition and melting point of inner and outer subcutaneous fat and inter- and intramuscular fat; the number of pigs examined was 479-521. Two SNPs (g.-353C>T and g.-233T>C) were identified in the promoter region of the SCD gene and were completely linked in the pigs from the base generation. In all pigs, 19 microsatellite markers and SCD haplotypes were then genotyped. Different statistical models were applied to evaluate the effects of QTL and the possible causality of the SCD gene variants with respect to the QTL. The results show that all significant QTL for C14:0, C18:0, C18:1 and melting point of fat were detected in the same region, located near the SCD gene. The results also show a significant association between SCD haplotypes and fatty acid composition and fat melting point in this population. These results indicate that the haplotype of the SCD gene has a strong effect on fatty acid composition and melting point of fat.