Molecular characterization of human adenovirus type 8 (HAdV-8), including a novel genome type detected in Japan

Human adenovirus type 8 (HAdV-8) is a common agent of severe epidemic keratoconjunctivitis (EKC). Twenty-six strains were isolated from sporadic cases of EKC in the southern part of Japan between 1998 and 1999 and were identified as HAdV-8 by the neutralization method using type-specific antiserum against HAdV-8. A comparative analysis of different HAdV-8 genome types was performed using various molecular methods. Restriction enzyme analyses of genomic DNA were performed with BamHI, HindIII, PstI, SacI, SalI, and SmaI and identified 25 isolates as HAdV-8E and 1 isolate as HAdV-8J, a novel genome type. The genetic relatedness between HAdV-8J and the other genome types was calculated by pairwise comigrating restriction fragments. The new genome type was most genetically related to HAdV-8E. In a phylogram of both the hexon and fiber, HAdV-8J formed a monophyletic cluster with other genome types of HAdV-8. Although HAdV-8J was identified from a sporadic case of EKC, this strain may cause future outbreaks and thus warrants further monitoring.     

The inhibition of apoptosis by melatonin in VSC4.1 motoneurons exposed to oxidative stress,glutamate excitotoxicity,or TNF‐α toxicity involves membrane melatonin receptors

Abstract: Loss of motoneurons may underlie some of the deficits in motor function associated with the central nervous system (CNS) injuries and diseases. We tested whether melatonin, a potent antioxidant and free radical scavenger, would prevent motoneuron apoptosis following exposure to toxins and whether this neuroprotection is mediated by melatonin receptors. Exposure of VSC4.1 motoneurons to either 50 μm H₂O₂, 25 μm glutamate (LGA), or 50 ng/mL tumor necrosis factor‐alpha (TNF‐α) for 24 h caused significant increases in apoptosis, as determined by Wright staining and ApopTag assay. Analyses of mRNA and proteins showed increased expression and activities of stress kinases and cysteine proteases and loss of mitochondrial membrane potential during apoptosis. These insults also caused increases in intracellular free [Ca²⁺] and activities of calpain and caspases. Cells exposed to stress stimuli for 15 min were then treated with 200 nm melatonin. Post‐treatment of cells with melatonin attenuated production of reactive oxygen species (ROS) and phosphorylation of p38, MAPK, and JNK1, prevented cell death, and maintained whole‐cell membrane potential, indicating functional neuroprotection. Melatonin receptors (MT1 and MT2) were upregulated following treatment with melatonin. To confirm the involvement of MT1 and MT2 in providing neuroprotection, cells were post‐treated (20 min) with 10 μm luzindole (melatonin receptor antagonist). Luzindole significantly attenuated melatonin‐induced neuroprotection, suggesting that melatonin worked, at least in part, via its receptors to prevent VSC4.1 motoneuron apoptosis. Results suggest that neuroprotection rendered by melatonin to motoneurons is receptor mediated and melatonin may be an effective neuroprotective agent to attenuate motoneuron death in CNS injuries and diseases.     

Adipocyte spatial distributions in bone marrow: implications for skeletal dosimetry models.

Few studies have been conducted to quantify the spatial distributions of adipocytes in the marrow cavities of trabecular bone. Nevertheless, such data are needed for the development of 3-dimensional (3D) voxel skeletal models where marrow cellularity is explicitly considered as a model parameter for dose assessment. In this investigation, bone marrow biopsies of the anterior iliac crest were examined to determine the size distribution of adipocyte cell clusters, the percentage of perimeter coverage of trabecular surfaces, and the presence or absence of adipocyte density gradients in the marrow space, all as a function of the biopsy marrow cellularity (5%-95%). METHODS: Biopsy slides from 42 patients were selected as designated by the hematopathologist as either normocellular or with no evidence of disease. Still-frame video image captures were made of 1-3 regions of interest per biopsy specimen, with subsequent image analysis of adipocyte spatial characteristics performed via a user-written MATLAB routine. RESULTS: A predictable shift was found in cluster size with decreasing marrow cellularity from single adipocytes to clusters of >or=3 cells; the percentage of 2-cell clusters remained relatively constant with changing cellularity. Also, a nonlinear increase in trabeculae perimeter coverage was found with increasing fat tissue fraction at marrow cellularities between 50% and 80%. Finally, it was demonstrated that only in the range of 20%-50% marrow cellularity was a slight gradient in adipocyte concentration indicated with adipocytes localized preferentially toward the trabecular surfaces. CONCLUSION: Electron transport simulations were conducted in 4 different 3D voxel models of trabecular bone for sources localized in the active marrow (TAM), bone volume (TBV), bone endosteum (TBE), and bone surfaces (TBS). Voxel model simulations demonstrated that absorbed fractions to active marrow given by the ICRP 30 model (MIRDOSE2) are exceedingly conservative for both TBV and TBS sources, except in the case of high-energy particles (>500 keV) at high values of marrow cellularity (>70%). Values of both phi(TAM<--TBV) and phi(TAM<--TBS) given by the Eckerman and Stabin model (MIRDOSE3) were shown to be reasonably consistent with 3D voxel model simulations at the reference cellularity of 25%, except in the case of low-energy emitters (<100 keV) on the bone surfaces.     

An image-based skeletal model for the ICRP reference adult male-specific absorbed fractions for neutron-generated recoil protons

Recoiling hydrogen nuclei are a principle mechanism for energy deposition from incident neutrons. For neutrons incident on the human skeleton, the small sizes of two contrasting media (trabecular bone and marrow) present unique problems due to a lack of charged-particle (protons) equilibrium. Specific absorbed fractions have been computed for protons originating in the human skeletal tissues for use in computing neutron dose response functions. The proton specific absorbed fractions were computed using a pathlength-based range-energy calculation in trabecular skeletal samples of a 40 year old male cadaver.     

Distribution of calcium-activated neutral proteinase activity in quaking mouse brain: a subcellular study

The distribution of calcium-activated neutral proteinase (CANP) activity was examined in the subcellular fractions of quaking and control mouse brain. The CANP activity was determined in purified myelin, cytosol and pellet (P2, consisting of nuclei, mitochondria and microsomes) fractions using [14C]azocasein as substrate. The enzyme activity in quaking brain was 1.3-fold greater than control. Fifty-seven percent of the control brain activity was in purified myelin compared to only 7% in quaking myelin. The specific activity of the control purified myelin was 4-fold greater than homogenate while that of the quaking was two-fold greater. In contrast, 51% of the quaking brain activity was present in cytosol compared to only 18% in the control. Triton X-100 greatly increased the control brain activity (10-fold) while the quaking brain activity was increased by only 1.2-fold. The total calcium content in the quaking brain was greatly elevated (6-fold) compared to control. Approximately 30% of the brain 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) activity was in quaking myelin while 77% of the CNPase activity in control brain was in myelin. These results suggest that in quaking brain much of the CANP is not incorporated into the myelin membrane and remains cytosolic.     

A study of morbidity pattern,nutritional status and various defects of urban primary school children in Delhi

Summary The morbidity pattern, nutritional deficiencies and various defects of the special senses, among 2773 primary school children in an urban community of Delhi are presented. The relevant literature is reviewed briefly and the preventable causes of illness highlighted. From the Survey on Morbidity and Mortality, Growth and Development, and Nutritional Status of Children in Delhi. Post Address: Flat 32, Shankar Market, New Delhi-1.     

Increased calpain content and progressive degradation of neurofilament protein in spinal cord injury

Spinal cord injury was induced in rat by weight drop. The extent of degradation of neurofilament proteins in the lesion following trauma was examined and served as a measure of calpain activity. Calpain was identified in the samples by myelin mealpain antibody and the content was estimated from the immunoblot. There was progressive degradation of both 68 kDa and 200 kDa neurofilament proteins in the cord lesion at intervals after injury. At 30 min after injury there was 20% degradation of both neurofilament proteins while the breakdown of 68 kDa and 200 kDa NFRs amounted to more than 60% at 24 h and beyond. Calpain content progressively increased in the lesion by 22% at 30 min to 91% at 4 h after trauma compared to control and then decreased but remained elevated for up to 72 h following injury. These results suggest that calpain is a primary responder synthesized early in injury and involved initially in the breakdown of cytoskeletal proteins in spinal cord trauma. Later in the injury cascade, increased calpain activity is derived from inflammatory as well as endogenous cells supporting a pivotal role for calpain throughout the process of secondary and evolving tissue damage in spinal cord trauma.