Progressive multifocal leukoencephalopathy (PML) is caused by JC polyomavirus (JCV) infection in the brain. JCV isolates from PML patients have variable mutations in the non-coding control region (NCCR) of the genome. This study was conducted to examine sequential changes in NCCR patterns of JCV isolates obtained from the cerebrospinal fluid (CSF) of PML patients. CSF specimens were collected from PML patients at different time points, the NCCR sequences were determined, and their compositions were assessed by computer-based analysis. In patients showing a marked increase in JCV load, the most frequent NCCR sequences in the follow-up specimens were different from those in the initial samples. In contrast, the dominant NCCRs in the CSF remained unaltered during the follow-up of individuals in whom the viral load decreased after therapeutic intervention. These data demonstrate that the majority of JCV variants emerge with the progression of PML and that these changes are suppressed when the viral load is decreased.

Dynactin forms a protein complex with dynein that retrogradely transports cargo along microtubules. Dysfunction of this dynein-dynactin complex causes several neurodegenerative diseases such as Perry syndrome, motor neuron diseases and progressive supranuclear palsy. Recently, we reported colocalization of phosphorylated α-synuclein (p-SNCA) and the largest subunit of dynactin (DCTN1) in Lewy body (LB)-like structures in Perry syndrome. Previous reports have not focused on the relationship between dynactin and synucleinopathies. Thus, we examined autopsied human brains from patients with Parkinson's disease, dementia with LBs, and multiple system atrophy using immunohistochemistry for p-SNCA, DCTN1, dynactin 2 (DCTN2, dynamitin) and dynein cytoplasmic 1 intermediate chain 1 (DYNC1I1). We also examined microtubule affinity-regulating kinases (MARKs), which phosphorylate microtubule-associated proteins and trigger microtubule disruption. Both brainstem-type and cortical LBs were immunopositive for DCTN1, DCTN2, DYNC1I1 and p-MARK and their staining often overlapped with p-SNCA. Lewy neurites were also immunopositive for DCTN1, DCTN2 and DYNC1I1. However, p-SNCA-positive inclusions of multiple system atrophy, which included both glial and neuronal cytoplasmic inclusions, were immunonegative for DCTN1, DCTN2, DYNC1I1 and p-MARK. Thus, immunohistochemistry for dynein-dynactin complex molecules, especially DCTN1, can clearly distinguish LBs from neuronal cytoplasmic inclusions. Our results suggest that dynactin is closely associated with LB pathology.

Central pontine myelinolysis (CPM), which was originally considered to be the result of rapid correction of chronic hyponatremia, is not necessarily accompanied by hyponatremia or drastic changes in serum sodium level. Here, we report a case of an anorexic 55-year-old male with a history of pharyngo-laryngo-esophagogastrectomy, initially hospitalized with status epilepticus. Although his consciousness gradually recovered as we were controlling his convulsion, it deteriorated again with new onset of anisocoria, and magnetic resonance imaging (MRI) at this point revealed CPM. Rapid change of serum sodium or osmolarity, which is often associated with CPM, had not been apparent throughout his hospitalization. Instead, a review of the serum biochemistry test results showed that serum phosphate had drastically declined the day before the MRI first detected CPM. In this case, we suspect that hypophosphatemia induced by refeeding syndrome greatly contributed to the occurrence of CPM.

The protein μ-crystallin (CRYM) is a novel component of the marsupial lens that has two functions: it is a key regulator of thyroid hormone transportation and a reductase of sulfur-containing cyclic ketimines. In this study, we examined changes of the expression pattern of CRYM in different rat organs during development using immunohistochemistry and immunoblotting. As CRYM is reportedly expressed in the corticospinal tract, we also investigated CRYM expression in human cases of amyotrophic lateral sclerosis (ALS) using immunohistochemistry. In the rat brain, CRYM was expressed in the cerebral cortex, basal ganglia, hippocampus and corticospinal tract in the early postnatal period. As postnatal development progressed, CRYM expression was restricted to large pyramidal neurons in layers V and VI of the cerebral cortex and pyramidal cells in the deep layer of CA1 in the hippocampus. Even within the same regions, CRYM-positive and negative neurons were distributed in a mosaic pattern. In the kidney, CRYM was expressed in epithelial cells of the proximal tubule and mesenchymal cells of the medulla in the early postnatal period; however, CRYM expression in the medulla was lost as mesenchymal cell numbers decreased with the rapid growth of the medulla. In human ALS brains, we observed marked loss of CRYM in the corticospinal tract, especially distally. Our results suggest that CRYM may play roles in development of cortical and hippocampal pyramidal cells in the early postnatal period, and in the later period, performs cell-specific functions in selected neuronal populations. In the kidney, CRYM may play roles in maturation of renal function. The expression patterns of CRYM may reflect significance of its interactions with T3 or ketimines in these cells and organs. The results also indicate that CRYM may be used as a marker of axonal degeneration in the corticospinal tract.

ABSTRACT:The zero-shear viscosity 11° of styrene-2-vinylpyridine diblock copolymers in semidilute solutions was measured in pyridine (a commonly good solvent), methyl ethyl ketone (MEK) (a commonly poor solvent) at 25°C, and in benzene (a selective solvent) at I l.4°C. It was found that the reduced zero-shear viscosity I'/~ ( = 1'/~p/C[11]) is expressed as a universal function of C [11] in all solvents, and the dependence of I'/~ on C[11] is determined by the exponent in the relationship between the radius of gyration and molecular weight of the block component which has the larger excluded volume, regardless of the solvent.KEY WORDS Zero-Shear Viscosity / Block Copolymer / Scaling Theory / Solvent Effect /