Acute manganese administration alters dopamine transporter levels in the non-human primate striatum

We used positron emission tomography (PET) to measure non-invasively the effect of acute systemic administration to manganese sulfate (MnSO4) on dopamine transporter (DAT) levels in the living non-human primate brain. Baboons received [11C]-WIN 35,428 PET scans to measure DAT levels before and after acute MnSO4 administration. In one animal, we observed a 46% increase in DAT binding potential (BP), a measure of DAT binding site availability, 1 week after Mn administration. DAT levels returned to baseline values at 4 months and remained constant at 10 months after treatment. A subsequent single MnSO4 injection to the same animal also resulted in a 57% increase in DAT-BP, 2 days after administration. In a second animal, a 76% increase in DAT-BP relative to baseline was observed at 3 days after Mn injection. In this animal, the DAT-BP returned to baseline levels after 1 month. Using in vitro receptor binding assays, we found that Mn inhibits [3H]-WIN 35,428 binding to rat striatal DAT with an inhibitory constant (Ki) of 2.0+/-0.3mM (n=4). Saturation isotherms and Scatchard analysis of [3H]-WIN 35,428 binding to rat striatal DAT showed a significant decrease (30%, p<0.001) in the maximal number of binding sites (Bmax) in the presence of 2mM MnSO4. No significant effect of Mn was found on binding affinity (Kd). We also found that Mn inhibits [3H]-dopamine uptake with an IC50 of 11.4+/-1.5mM (n=4). Kinetic studies and Lineweaver-Burk analysis showed a significant decrease (40%, p<0.001) in the maximal velocity of uptake (Vmax) with 5mM MnSO4. No significant effect of Mn was found on Michaelis-Menten constant (Km). These in vitro findings suggest that the increase in DAT levels in vivo following acute Mn administration may be a compensatory response to its inhibitory action on DAT. These findings provide helpful insights on potential mechanisms of Mn-induced neurotoxicity and indicate that the DAT in the striatum is a target for Mn in the brain.     

Hyposalivation in autoimmune diseases

We have investigated the prevalence of dry mouth among patients with autoimmune diseases other than Sjögren’s syndrome. One hundred and forty-four patients, excluding patients with primary Sjögren’s syndrome, were enrolled in this study. The volume of saliva secreted was measured with the screening technique for estimation of salivary flow, which uses a filter paper for diagnosing dry mouth. Disturbed salivary secretion was observed in 84 (58.3 %) of the 144 patients. In the case of patients free of Sjögren’s syndrome, the prevalence of disturbed salivary secretion differed significantly among the disease groups (P < 0.05), with the prevalence being over 50 % in all disease groups other than the rheumatoid arthritis group and the highest in the systemic sclerosis group. There was significant positive correlation between the number of colored spots and oral visual analog scale score (r = 0.45, P < 0.0001). Autoimmune diseases can be accompanied by salivary gland dysfunction, regardless of the presence/absence of complication by Sjögren’s syndrome. In the present study, the screening technique for estimation of salivary flow, which uses a filter paper for diagnosing dry mouth, was shown to be a useful means of detecting salivary gland dysfunction.     

Body mass index is the most useful predictive factor for the onset of nonalcoholic fatty liver disease: a community-based retrospective longitudinal cohort study

Background

Nonalcoholic fatty liver disease (NAFLD) can progress to advanced liver disease and non-liver-related diseases. To prevent NAFLD onset, clinicians must be able to easily identify high-risk NAFLD patients so that intervention can begin at an earlier stage. We sought to identify the predictive factors for NAFLD onset.

Methods

In a community-based, longitudinal design, the records of 6,403 Japanese subjects were reviewed to identify those meeting the criteria for NAFLD onset. Univariate and multivariate logistic regression analyses were used to identify predictive factors for NAFLD onset. The accuracy of different models was evaluated according to their areas under the receiver operating characteristic curves. Comparative risk analysis was performed using the Kaplan–Meier method.

Results

Multivariate analysis of 400 subjects who met the criteria for the onset of NAFLD during the observation period confirmed that body mass index (BMI) at baseline was the most useful predictive factor for NAFLD onset in both sexes. Cutoff levels of BMI for NAFLD onset were estimated at 23 kg/m² for men and 22.2 kg/m² for women. The cumulative onset rate of NAFLD was significantly higher in the high BMI group than in the low BMI group in both sexes (P < 0.001).

Conclusion

BMI was confirmed as the most useful predictive factor for NAFLD onset in both sexes; its cutoff levels were similar to those recommended by the World Health Organization for helping to prevent metabolic disease. An accurate BMI cutoff level will enable clinicians to identify subjects at risk for NAFLD onset.     

Mitochondrial Delivery of Bongkrekic Acid Using a MITO-Porter Prevents the Induction of Apoptosis in Human HeLa Cells

The fact that mitochondrial dysfunction has been implicated in a variety of human diseases suggests that they would be expected as a target organelle for these diseases. Bongkrekic acid (BKA) is a chemical that functions as a ligand of the adenine nucleotide translocator and is known to potently inhibit the mitochondrial permeability transition that is associated with apoptosis. Thus, delivering it to mitochondria would be an innovative therapy for the treatment of mitochondrial diseases that are largely associated with apoptosis. Here, we report on the use of a MITO-Porter, an innovative nanocarrier for mitochondrial delivery via mitochondrial membrane fusion, for delivering BKA to mitochondria. We first constructed a BKA-MITO-Porter, in which BKA is contained in lipid envelopes of a MITO-Porter. We then confirmed that the BKA–MITO-Porter was efficiently internalized into cells and is delivered to mitochondria, similar to a conventional MITO-Porter. Moreover, we evaluated the antiapoptosis effect of the BKA–MITO-Porter in HeLa cells by measuring caspase 3/7 activity. The findings confirmed that the BKA–MITO-Porter showed a strong antiapoptosis effect compared with naked BKA. The results reported here demonstrate its potential for the use in therapies aimed at mitochondrial diseases, as a mitochondrial medicine candidate. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:1008–1015, 2013     

Radiographic findings for solitary plasmacytoma of the bone in the anterior wall of the maxillary sinus: A case report

Radiographic findings for a solitary plasmacytoma of the anterior wall of the maxillary sinus are reported. The diagnostic evaluation for this disease is discussed through use of plain images, computed tomography, and magnetic resonance imaging. The treatment selected was radiation therapy combined with chemotherapy. Computed tomography and magnetic resonance imaging revealed bone destruction, though this was not apparent on plain images. T(1)-weighted magnetic resonance images showed similar or high signal intensity relative to muscle; T(2)-weighted images showed hyperintensity.     

Evaluation in vitro of the efficacy of colistin methanesulfonate against biofilm-forming multidrug-resistant Pseudomonas aeruginosa (MDRP)

The aim of this study was to evaluate in vitro the efficacy of clinically using colistin methanesulfonate against biofilm-forming multidrug-resistant Pseudomonas aeruginosa (MDRP), with minimum inhibitory concentrations (MICs) of ciprofloxacin, imipenem, and amikacin showing ≥4, 16, and 32 μg/ml, respectively, by disk diffusion susceptibility testing (CLSI document M100-S21). The minimum eradication biofilm concentration (MBEC) of colistin methanesulfonate for strain MDRP-YMD isolated from a patient’s urine, which formed a biofilm on plastic pegs attached to a microplate lid, was compared with that of P. aeruginosa ATCC27853 for quality control testing with MICs of ciprofloxacin, imipenem, and amikacin showing ≤1, 4, and 16 μg/ml, respectively. In an uneven biofilm approximately 10 μm thick, as determined with confocal laser scanning microscopy (CLSM), ratios of MBEC to MIC of colistin methanesulfonate against strains MDRP-YMD and ATCC27853 were 10.5 and 8.0, whereas those of minimum bactericidal concentration (MBC) to MIC in planktonic cells were 1.0 and 2.0 μg/ml, respectively. Morphological examination using scanning electron microscopy and CLSM verified that embedded cells in biofilm matrices of the two strains were disrupted and died under the MBEC. Therefore, bactericidal effects of colistin methanesulfonate on biofilm-forming cells of strain MDRP-YMD as well as strain ATCC27853 were significantly decreased compared with those on the planktonic cells.     

Optimization of allograft implantation using scaffold-free chondrocyte plates

If a tissue-engineered cartilage transplant is to succeed, it needs to integrate with the host tissue, to endure physiological loading, and to acquire the phenotype of the articular cartilage. Although there are many reported treatments for osteochondral defects of articular cartilage, problems remain with the use of artificial matrices (scaffolds) and the stage of implantation. We constructed scaffold-free three-dimensional tissue-engineered cartilage allografts using a rotational culture system and investigated the optimal stage of implantation and repair of the remodeling site. We evaluated the amounts of extracellular matrix and gene expression levels in scaffold-free constructs and transplanted the constructs for osteochondral defects using a rabbit model. Allografted 2-week constructs expressed high levels of proteoglycan and collagen per DNA content, integrated with the host cartilage successfully, and were able to counter physiological loads, and the chondrocyte plate contributed reparative mesenchymal stem cells to the final phenotype of the articular cartilage.     

Neuromuscular synaptic function in mice lacking major subsets of gangliosides

Gangliosides are a family of sialylated glycosphingolipids enriched in the outer leaflet of neuronal membranes, in particular at synapses. Therefore, they have been hypothesized to play a functional role in synaptic transmission. We have measured in detail the electrophysiological parameters of synaptic transmission at the neuromuscular junction (NMJ) ex vivo of a GD3-synthase knockout mouse, expressing only the O- and a-series gangliosides, as well as of a GM2/GD2-synthase*GD3-synthase double-knockout (dKO) mouse, lacking all gangliosides except GM3. No major synaptic deficits were found in either null-mutant. However, some extra degree of rundown of acetylcholine release at high intensity use was present at the dKO NMJ and a temperature-specific increase in acetylcholine release at 35 degrees C was observed in GD3-synthase knockout NMJs, compared with wild-type. These results indicate that synaptic transmission at the NMJ is not crucially dependent on the particular presence of most ganglioside family members and remains largely intact in the sole presence of GM3 ganglioside. Rather, presynaptic gangliosides appear to play a modulating role in temperature- and use-dependent fine-tuning of transmitter output.