Spatiotemporal changes of coxsackievirus and adenovirus receptor in rat hearts during postnatal development and in cultured cardiomyocytes of neonatal rat

Coxsackievirus B is the most common cause of viral myocarditis and is particularly virulent in neonates and children. Adenovirus is also a leading cause of the disease. The determinant of tropism for both viruses is considered to be the expression of coxsackievirus and adenovirus receptor (CAR) in target organs. However, developmental change and physiological localization of CAR in the heart are unknown. We examined expression levels of CAR in rat hearts by quantitative real-time polymerase chain reaction and Western blot analysis and found that CAR decreased gradually during postnatal development, although CAR was detectable, even in adults. Immunohistochemistry revealed CAR on the whole surface of cardiomyocytes in immature rat hearts. In contrast, CAR was detected predominantly on intercalated disks in the adult heart and was accumulated especially at the contact point between the cultured cardiomyocytes, even though they were prepared from the neonatal rat heart. In conclusion, CAR was expressed abundantly on the whole surface of cardiomyocytes in immature rat hearts. Both the expression level and the localization of CAR are possible determinants of the susceptibility to viral myocarditis of neonates and children.     

Polyethylene/phospholipid polymer alloy as an alternative to poly(vinylchloride)-based materials

To develop new biomaterials for making medical devices, polymer alloys composed of a phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), and polyethylene (PE) were prepared. The PE/PMPC alloy membrane could be obtained by a combination of solution mixing and solvent evaporation methods using xylene and n-butanol mixture as a solvent. Moreover, thermal treatment was applied to improve the mechanical properties of the PE/PMPC alloy membrane. In the PE/PMPC alloy membrane, the PMPC domains were located not only inside the membrane but also at the surface. Surface analysis of the PE/PMPC alloy membrane with X-ray photoelectron spectroscopy, wettability evaluation, and dynamic contact angle measurements revealed that the phospholipid polar groups in the PMPC covered the surface even after thermal treatment. Blood compatibility tests with attention to platelet adhesion and change in morphology of adhered platelets showed that the PE/PMPC alloy membrane had excellent platelet adhesion resistance. We finally concluded that the PE/PMPC alloy could be used as biomaterials instead of poly(vinyl chloride)-based materials.     

Immunocytochemical Localization of Caveolin‐3 in the Synoviocytes of the Rat Temporomandibular Joint During Development

Caveolins—caveolin‐1, ‐2, ‐3 (Cav1, 2, 3)—are major components of caveolae, which have diverse functions. Our recent study on the temporomandibular joint (TMJ) revealed expressions of Cav1 and muscle‐specific Cav3 in some synovial fibroblast‐like type B cells with well‐developed caveolae. However, the involvement of Cav3 expression in the differentiation and maturation of type B cells remains unclear. The present study therefore examined the chronological alterations in the localization of Cav3 in the synovial lining cells of the rat TMJ during postnatal development by immunocytochemical techniques. Observations showed immature type B cells possessed a few caveolae with Cav1 but lacked Cav3 protein at postnatal day 5 (P5). At P14, Cav3‐immunopositive type B cells first appeared in the synovial lining layer. They increased in number and immunointensity from P14 to P21 as occlusion became active. In immunoelectron microscopy and double immunolabeling with heat shock protein 25 (Hsp25) and Cav3, coexpressed type B cells developed rough endoplasmic reticulum and numerous caveolae, while the Cav3‐immunonegative type B cell with Hsp25 immunoreaction possessed few of these. Results suggest that Cav3 expression, which is closely related to added functional stimuli, reflects the differentiation of the type B synoviocytes. Anat Rec, 291:233–241, 2008. © 2008 Wiley‐Liss, Inc.     

Dynamic changes in corticospinal excitability during motor imagery

 We investigated temporal changes in the amplitudes of motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation over the left motor cortex during motor imagery. Nine subjects were instructed to imagine repetitive wrist flexion and extension movements at 1 Hz, in which the flexion timing was cued by a tone signal. Electromyographs (EMGs) were recorded from the first dorsal interosseous, flexor carpi radialis and extensor carpi radialis muscles of the right hand, and magnetic stimulation was delivered at 0, 250, 500 and 750 ms after the auditory cue. On average, the evoked EMG responses were larger in the flexor muscle during the phase of imagined flexion than during extension, whilst the opposite was true for the extensor muscle. There were no consistent changes in the amplitudes of MEPs in the intrinsic hand muscle (first dorsal interosseous). The EMG remained relaxed in all muscles and did not show any significant temporal changes during the test. The H-reflex in the flexor muscle was obtained in four subjects. There was no change in its amplitude during motor imagery. These observations lead us to suggest that motor imagery can have dynamic effects on the excitability of motor cortex similar to those seen during actual motor performance. Received: 23 July 1998 / Accepted: 26 October 1998     

CD95 ligand is expressed in Reed–Sternberg cells of Hodgkin's disease

Reed-Sternberg (RS) cells and their mononuclear variants, Hodgkin's (H) cells, are considered to be the neoplastic cells of Hodgkin's disease (HD). The cellular origin of H-RS cells remains the subject of considerable controversy, although most recent papers have claimed that H-RS cells are of B cell origin. Recently, however, it has been reported that some H-RS cells express granzyme B, as observed in cytotoxic T cells and/or natural killer cells, which also express CD95 ligand (FasL/APO-1L). In the present study, the expression of CD95L and granzyme B in H-RS cells of HD was investigated. CD95L was detected in H-RS cells in five of nine HD cases (one case of lymphocyte-rich classical HD, two of these cases of nodular sclerosis type, and two of four cases of mixed cellularity type). All three examined HD cell lines expressed CD95L in the cytoplasm, although cell surface expression was seen only in L428 cells. Three HD cases expressed both CD95L and granzyme B. It was concluded that CD95L is frequently expressed in H-RS cells, which is one of their notable characteristics; albeit it seems to be irrespective of cell lineage.     

Secretion of human atrial natriuretic peptide in response to atrial pacing and its function in patients with ventricular septal defect

The capacity to secrete human atrial natriuretic peptide (hANP) in response to atrial pacing and the resulting changes in diuresis and urinary electrolyte excretion were compared in children with and without a ventricular septal defect (VSD). The subjects examined were 9 children with a history of Kawasaki disease (as controls) and 11 patients with a VSD, including 5 patients with congestive heart failure (CHF). Their ages ranged from 6 to 40 months old. Atrial pacing resulted in a significant increase in the plasma hANP level from 40 +/- 19 to 140 +/- 37 pg/ml in the controls and from 757 +/- 762 to 1540 +/- 1160 pg/ml in the VSD patients. In control children, the urinary flow rate increased 2.3-fold, urinary sodium excretion increased 6.2-fold and urinary chloride excretion increased 7.6-fold, but these values increased only slightly in VSD patients, especially in those patients with CHF, in spite of the marked increase in their plasma hANP level. These results indicate that the capacity for hANP secretion was increased in VSD patients who had chronic volume overloading of the left atrium, but that their diuresis and urinary electrolyte excretion in response to hANP were attenuated.     

The D5Mit7 locus on mouse chromosome 5 provides resistance to gamma-ray-induced but not N-methyl-N-nitrosourea-induced thymic lymphomas

Susceptibility to gamma-ray induction of thymic lymphomas in mouse strains is controlled by low-penetrance genetic variant alleles. Our previous genome-wide scan of a mouse backcross between BALB/c and MSM strains suggested the existence of a BALB/c resistance locus near D5Mit5 on chromosome 5. To confirm this resistance, we produced congenic mice carrying a 28.4 cM region between D5Mit4 and D5Mit315 from the MSM parental strain on the BALB/c background. Lymphomas were induced in their progeny by gamma-ray irradiation or administration of N-methyl-N-nitrosourea (MNU), an alkylating agent. The incidence of radiogenic lymphomas was 87.5% in mice of the M/M genotype at D5Mit7, significantly higher than the 46% incidence in mice of the C/M genotype, indicating highly significant linkage between the locus and the resistance (P = 0.000054). In contrast, the frequencies of MNU-induced thymic lymphomas were similar between the two genotypes (P = 0.35 in chi2 test). These results confirm the presence of a resistance allele for gamma-ray induction of thymic lymphomas near the D5Mit7 locus and strongly suggest that this locus modifies carcinogenic risk from exposure to radiation but not to alkylating agents.     

The clinical criteria for Carpentier-Edwards bioprosthesis in the mitral position

This is a comparative study of late results of mitral valve replacement between Carpentier-Edwards (C-E) and Bj?rk-Shiley (B-S) valve prosthesis. The purpose of this study is to clarify the clinical criteria for C-E valve. C-E valve was implanted in 202 patients. The mean follow up period was 5.8 years and the longest one was 11 years. For B-S valve, it was 132 patients, 5.3 years and 17 years, respectively. With respect to the incidence of thromboembolic episodes, in spite of no anticoagulant therapy in the C-E group, there was no statistical difference between the C-E and the B-S groups. The incidence of valve related complication in the C-E group was significantly lower than that in the B-S group 5 years postoperatively. But that in the B-S group was significantly low 10 years postoperatively. Since the over 60 years old patients in the C-E group had low incidence of primary tissue failure, over ten years durability might be secured. In conclusion, the present clinical criteria for C-E valve should be as follows: 1) the patient older than 65 years, 2) the patient with contraindication for anticoagulant therapy, 3) the woman who desires pregnancy and 4) the patient with hemorrhagic diathesis caused by cardiac cachexia, liver cirrhosis and so on.