Microbial contamination of nebulization solution and its measures

We evaluated the microbial contamination of nebulization solutions in medication cups from a total of 76 ultrasonic nebulizers in use in 10 hospitals. In addition, an interview survey was given to nurses to evaluate the disinfection methods of these ultrasonic nebulizers. Of a total of 76 nebulization solution samples, 11 (14.5%) were contaminated with 10-10(2) colony-forming units (CFU)/ml and 9 (11.8%) with 10(3)-10(5) CFU/ml. The major contaminants were glucose non-fermentative bacilli such as Burkholderia cepacia, CDC gr.IV C-2, and Sphingomonas paucimobilis. Comparison of microbial contamination between the frequencies of disinfection showed a significantly lower number of contaminated samples when the cups were disinfected once daily than when disinfected once at intervals of 2-7 d (p=0.00037). In addition, comparison between the presence and absence of preservatives contained in the nebulization solution showed a significantly lower number of contaminated samples in the presence, rather than in the absence, of preservatives (p=0.00001). These results show that disinfection of ultrasonic nebulizers at 24-h intervals is desirable. In particular, when nebulization solutions not containing preservatives are used, disinfection at 24-h intervals is indispensable.     

Systemic blood pressure profile correlates with cardiac 123I-MIBG uptake in patients with Parkinson's disease

To examine the correlation between the systemic blood pressure profile and cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake in patients with Parkinson's disease (PD), we monitored circadian blood pressure patterns of 37 PD patients of 49 to 85 years of age (mean, 71.8±8.4 years) using a portable blood pressure monitoring device. The duration of PD was 0.5 to 15 years, and the disability level (modified Hoehn and Yahr stage) ranged from 1.0 to 4.0 (mean, 2.7±0.7). There were 37 age- and sex-matched control subjects. Cardiac MIBG scintigraphy was performed for the 37 PD patients. Based on the nocturnal fall in mean arterial blood pressure (MABP), we classified patients into extreme dippers (nocturnal reduction of MABP >20%), dippers (>10% but <20%), nondippers (<10% but >0%), and inverted dippers (<0%). Average 24-hour MABP values revealed reduced BP variability in PD patients. The percentage nocturnal fall in MABP was significantly different between PD patients and control subjects (p<0.05). Significant correlations were found between % MABP reduction and the heart-to-mediastinum (H/M) ratio on early and delayed images (p<0.01). The UPDR motor score, early and delay H/M ratios were also significantly different between patients who were and were not dippers (p<0.05). The present results reported for the first time a significant correlation between the systemic blood pressure profile and cardiac (123)I-MIBG uptake in patients with PD. The degeneration between the brainstem and the postganglionic neurons of myocardial sympathetic nerves may progress in parallel in patients with PD.     

Serial diffusion-weighted MRI and SPECT findings in a Creutzfeldt-Jakob disease patient with V180I mutation

We report serial changes of diffusion-weighted imaging (DWI) and single photon emission computed tomography (SPECT) in a patient with Creutzfeldt-Jakob disease with V180I mutation (CJD180). DWI abnormalities in our patient were more predominantly observed in the left cerebral cortex than left basal ganglia. Hemilateral abnormalities progressed over 5 months to involve the contralateral side with increasing DWI signals. At 6 months, SPECT showed hypoperfusion in the left parietal and frontal lobes and the hypoperfusion region spread to the bilateral basal ganglia, right parietal and frontal lobes. SPECT imaging revealed marked cerebral blood flow reduction, predominantly in the cerebral cortex corresponding to brain areas with high-intensity DWI signals. During the follow-up period of CJD180, DWI was more sensitive than conventional FLAIR and T2-weighted images (T2WI) to detect and monitor the progression of abnormal hyperintense lesions. We suggest that serial DWI and SPECT findings are useful for not only early diagnosis of CJD but also for monitoring disease progression.     

Effects of structural variations of APOBEC3A and APOBEC3B genes in chronic hepatitis B virus infection

Aim: Human APOBEC3 deaminases induce G to A hypermutation in nascent DNA strand of hepatitis B virus (HBV) genomes and seem to operate as part of the innate antiviral immune system. We analyzed the importance of APOBEC3A (A3A) and APOBEC3B (A3B) proteins, which are potent inhibitors of adeno‐associated‐virus and long terminal repeat (LTR)‐retrotransposons, in chronic HBV infection. Methods: We focused on the common deletion polymorphism that spans from the 3′ part of A3A gene to the 3′ portion of A3B gene. An association study was carried out in 724 HBV carriers and 469 healthy control subjects. We also analyzed hypermutated genomes detected in deletion and insertion (non‐deletion) homozygous patients to determine the effect of APOBEC3 gene deletion. Further, we performed functional analysis of A3A gene by transient transfection experiments. Results: The association study showed no significant association between deletion polymorphism and chronic HBV carrier state. Context analysis also showed a negligible effect for the deletion. Rather, mild liver fibrosis was associated with APOBEC gene deletion homozygosity, suggesting that A3B deletion is not responsible for chronic HBV infection. Functional analysis of A3A showed that overexpression of A3A induced hypermutation in HBV genome, although the levels of hypermutants were less than those introduced by A3G. However, overexpression of A3A did not decrease replicative intermediates of HBV. Conclusion: These results suggest that A3A and A3B play little role in HBV elimination through anti‐viral defense mechanisms. The significance of hypermutation induced by A3A should be investigated further.