Intracranial Somatosensory Responses with Direct Spinal Cord Stimulation in Anesthetized Sheep

The efficacy of spinal cord stimulators is dependent on the ability of the device to functionally activate targeted structures within the spinal cord, while avoiding activation of near-by non-targeted structures. In theory, these objectives can best be achieved by delivering electrical stimuli directly to the surface of the spinal cord. The current experiments were performed to study the influence of different stimulating electrode positions on patterns of spinal cord electrophysiological activation. A custom-designed spinal cord neurostimulator was used to investigate the effects of lead position and stimulus amplitude on cortical electrophysiological responses to spinal cord stimulation. Brain recordings were obtained from subdural grids placed in four adult sheep. We systematically varied the position of the stimulating lead relative to the spinal cord and the voltage delivered by the device at each position, and then examined how these variables influenced cortical responses. A clear relationship was observed between voltage and electrode position, and the magnitude of high gamma-band oscillations. Direct stimulation of the dorsal column contralateral to the grid required the lowest voltage to evoke brain responses to spinal cord stimulation. Given the lower voltage thresholds associated with direct stimulation of the dorsal column, and its possible impact on the therapeutic window, this intradural modality may have particular clinical advantages over standard epidural techniques now in routine use.     

Illicit Drug Use Is a Significant Risk Factor for Loss to Follow Up in Patients with HIV-1 Infection at a Large Urban HIV Clinic in Tokyo

Background

Loss to follow up (LTFU) is an important prognostic factor in patients with HIV-1 infection. The impact of illicit drug use on LTFU of patients with HIV-1 infection is unknown in Japan.

Methods

A single center observational study was conducted to elucidate the impact of illicit drug use on LTFU at a large HIV clinic in Tokyo. LTFU was defined as those who discontinued their visits to the clinic for at least 12 months and were not known to be under the care of other facilities or have died within 12 months of their last visit. Patients who first visited the clinic between January 2005 and August 2010 were enrolled. Information on illicit drug use was collected in a structured interview and medical charts. Comparison of the effects of illicit drug use and no use on LTFU was conducted by uni- and multi-variate Cox hazards models as the primary exposure.

Results

The study subjects were 1,208 patients, mostly Japanese men, of relatively young age, and infected through homosexual contact. A total of 111 patients (9.2%) were LTFU (incidence: 24.9 per 1,000 person-years). Among illicit drug users and non users, 55 (13.3%) and 56 (7.1%) patients, respectively, were LTFU, with incidence of 35.7 and 19.2 per 1,000 person-years, respectively. Uni- and multi-variate analyses showed that illicit drug use was a significant risk for LTFU (HR=1.860; 95% CI, 1.282-2.699; p=0.001) (adjusted HR=1.544; 95% CI, 1.028-2.318; p=0.036). Multivariate analysis also identified young age, high CD4 count, no antiretroviral therapy, and no health insurance as risk factors for LTFU.

Conclusions

The incidence of LTFU among illicit drug users was almost twice higher than that among non users. Effective intervention for illicit drug use in this population is warranted to ensure proper treatment and prevent the spread of HIV.     

Meningitis and bacteremia by nonhemolytic Group B Streptococcus strain: A whole genome analysis

Group B streptococcus (GBS) is a leading cause of neonatal infections. Most isolates are β-hemolytic, and their activity is considered to be pivotal for GBS pathogenicity. We report a case of a neonate with meningitis caused by nonhemolytic GBS. The patient developed meningitis 3 days after birth. Genotyping was performed and the characteristics of the strain (GCMC97051) identified by whole genome sequence using next generation sequencing. GCMC97051 possesses genetic alterations such as disruption of cylA by IS1381A insertion and a frameshift mutation in cylE, resulting in a lack of hemolysis. Thus, nonhemolytic GBS can retain the potential to cause invasive infections.     

Sequence-specific microscopic visualization of DNA methylation status at satellite repeats in individual cell nuclei and chromosomes

Methylation-specific fluorescence in situ hybridization (MeFISH) was developed for microscopic visualization of DNA methylation status at specific repeat sequences in individual cells. MeFISH is based on the differential reactivity of 5-methylcytosine and cytosine in target DNA for interstrand complex formation with osmium and bipyridine-containing nucleic acids (ICON). Cell nuclei and chromosomes hybridized with fluorescence-labeled ICON probes for mouse major and minor satellite repeats were treated with osmium for crosslinking. After denaturation, fluorescent signals were retained specifically at satellite repeats in wild-type, but not in DNA methyltransferase triple-knockout (negative control) mouse embryonic stem cells. Moreover, using MeFISH, we successfully detected hypomethylated satellite repeats in cells from patients with immunodeficiency, centromeric instability and facial anomalies syndrome and 5-hydroxymethylated satellite repeats in male germ cells, the latter of which had been considered to be unmethylated based on anti-5-methylcytosine antibody staining. MeFISH will be suitable for a wide range of applications in epigenetics research and medical diagnosis.     

Metronomic chemotherapy with low-dose cyclophosphamide plus gemcitabine can induce anti-tumor T cell immunity in vivo

Several chemotherapeutic drugs have immune-modulating effects. For example, cyclophosphamide (CP) and gemcitabine (GEM) diminish immunosuppression by regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), respectively. Here, we show that intermittent (metronomic) chemotherapy with low-dose CP plus GEM can induce anti-tumor T cell immunity in CT26 colon carcinoma-bearing mice. Although no significant growth suppression was observed by injections of CP (100 mg/kg) at 8-day intervals or those of CP (50 mg/kg) at 4-day intervals, CP injection (100 mg/kg) increased the frequency of tumor peptide-specific T lymphocytes in draining lymph nodes, which was abolished by two injections of CP (50 mg/kg) at a 4-day interval. Alternatively, injection of GEM (50 mg/kg) was superior to that of GEM (100 mg/kg) in suppressing tumor growth in vivo, despite the smaller dose. When CT26-bearing mice were treated with low-dose (50 mg/kg) CP plus (50 mg/kg) GEM at 8-day intervals, tumor growth was suppressed without impairing T cell function; the effect was mainly T cell dependent. The metronomic combination chemotherapy cured one-third of CT26-bearing mice that acquired tumor-specific T cell immunity. The combination therapy decreased Foxp3 and arginase-1 mRNA levels but increased IFN-γ mRNA expression in tumor tissues. The percentages of tumor-infiltrating CD45⁺ cells, especially Gr-1^high CD11b⁺ MDSCs, were decreased. These results indicate that metronomic chemotherapy with low-dose CP plus GEM is a promising protocol to mitigate totally Treg- and MDSC-mediated immunosuppression and elicit anti-tumor T cell immunity in vivo.     

Neurite Outgrowth of PC12 Cells by 4′-O-β-d-Glucopyranosyl-3′,4-Dimethoxychalcone from Brassica rapa L. ‘hidabeni’ was Enhanced by Pretreatment with p38MAPK Inhibitor

The cellular effects of eleven compounds including chalcone glycosides isolated from Brassica rapa L. ‘hidabeni’ and their synthetic derivatives were studied in rat pheochromocytoma PC12 cells. Of the compounds tested, 4′-O-β-d-glucopyranosyl-3′,4-dimethoxychalcone (A2) significantly increased the levels of the phosphorylated forms of extracellular signal-regulated kinases 1/2 (ERK 1/2), p38 mitogen-activated protein kinase (p38MAPK), and stress-activated protein kinases/Jun amino-terminal kinases (JNK/SAPK), but it did not affect Akt. Nerve growth factor (NGF), a well-known neurotrophic factor, increased the levels of phosphorylated ERK1/2, JNK/SAPK, and Akt but not p38MAPK, which may mediate marked neurite outgrowth. Signals evoked by A2 shared common characteristics with those induced by NGF; therefore, we evaluated the neuritogenic activity of A2 and found it induced only weak neurite outgrowth. However, this effect was enhanced by pre-treatment with a p38MAPK inhibitor, suggesting that the phosphorylation of p38MAPK down-regulated neurite outgrowth. From the results of this study, it was found that A2 in combination with a p38MAPK inhibitor can induce NGF-like effects. Hence, a combination of chalcone glycosides containing A2 and a p38MAPK inhibitor increases the likelihood that chalcone glycosides could be put to practical use in the form of drugs or alternative medicines to maintain neural health.     

Base composition and nucleosome density in exonic and intronic regions in genes of the filamentous ascomycetes Aspergillus nidulans and Aspergillus oryzae

We sequenced nucleosomal DNA fragments of the filamentous ascomycetes Aspergillus nidulans and Aspergillus oryzae and then mapped those sequences on their genomes. We compared the GC content and nucleosome density in the exonic and intronic regions in the genes of A. nidulans and A. oryzae. Although the GC content and nucleosome density in the exonic regions tended to be higher than those in the intronic regions, the difference in the distribution of the GC content was more notable than that of the nucleosome density. Next, we compared the GC content and nucleosome density in the exonic regions of 9616 orthologous gene pairs. In both Aspergillus species, the GC content did not correlate with the nucleosome density. In addition, the Spearman's rank correlation coefficient (ρ = 0.51) between the GC content of the exonic regions of the 9616 orthologous gene pairs was higher than that (ρ = 0.31) of the nucleosome densities of A. nidulans and A. oryzae. These results strongly suggest that the GC content in the exons of the orthologous gene pairs has been conserved during evolution but the nucleosome density has varied throughout.     

A Japanese child with geleophysic dysplasia caused by a novel mutation of FBN1

Geleophysic dysplasia (GD) is a rare disorder characterized by severe short stature, short hands and feet, limited joint mobility, skin thickening, characteristic facial features (e.g., a “happy” face), and cardiac valvular disorders that often result in an early death. The genes ADAMTSL2 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif-like 2) and FBN1 (fibrillin 1) were recently identified as causative genes for GD. Here, we describe a 10-year-old Japanese female with GD who was born to non-consanguineous parents. At the age of 11 months, she was referred to our hospital because of very short stature for her age (− 4.4 standard deviations of the age-matched value) and a “happy” face with full cheeks, a shortened nose, hypertelorism, and a long and flat philtrum, characteristic of GD. Her hands and feet were small, her skin was thickened, and her joint mobility was generally limited. She had cardiac valvular disorders and history of recurrent respiratory failure. Mutation analysis revealed no abnormalities in ADAMTSL2. However, analysis of FBN1 revealed a novel heterozygous mutation (c.5161T > T/G) in exon 41, which encodes transforming growth factor-β-binding protein-like domain 5 (TB5). GD is an extremely rare disorder and, to our knowledge, only one case of GD with an FBN1 mutation has been reported in Japan. Similar to the previously reported cases of GD, the mutation in the current patient was located in the TB5 domain, which suggests that abnormalities in this domain of FBN1 are responsible for GD.