Characterization of junctional sarcoplasmic reticulum Ca2+ content and release by short-term mechanical restitution in cardiac muscle

To study Ca2+ handling by the junctional sarcoplasmic reticulum (JSR), the time course of short-term mechanical restitution after varying magnitudes of twitch contractions was assessed in rat papillary muscle. Mechanical restitution consisted of a pretwitch latency period followed by a rapid and a subsequent much slower restitution of twitch force. The rate of rapid restitution was independent of the magnitude of the preceding twitch, which suggests that the rate of JSR Ca2+ repletion was dependent on the amount of Ca2+ remaining in the JSR after a twitch contraction. Based on this finding, the functions Gt and Ht, representing the time courses of JSR Ca2+ repletion and release, respectively, were derived graphically from a family of the mechanical restitution curves. Gt increased monotonically with time at a decreasing rate, while Ht increased with time in a sigmoid manner. The mechanical alternans were simulated by using experimental values and mathematically predicted values of Gt and Ht. A substitution of extracellular Na+ with Li+ to inhibit Na+/Ca2+ exchange resulted in an augmentation of Gt by approximately 10%, presumably by increasing the tubular SR Ca2+ uptake. The inhibition of tubular SR Ca2+ uptake by thapsigargin (10 microM) reduced mechanical restitution by approximately 13% of the maximal twitch force, independent of the phase of mechanical restitution; the effect was greater at an earlier time point in the mechanical restitution. These results suggest that early JSR Ca2+ replenishment results mainly from the movement of Ca2+ from the tubular SR.     

Influence of the parameters of several pulse sequences on the image contrast: comparison between the two major contrast media

We compared the influences of the parameters of several pulse sequences using two major commercially available gadolinium (Gd) contrast media for MR imaging. The phantom of Gd solutions of various concentration (0.1 - 10mmol/L) was prepared, and was scanned with a 1.5T clinical MR unit, using a spin-echo T1-weighted sequence, 2DFLASH, 3DFLASH, and 3DVIBE. The signal intensity was measured and the contrast enhancement ratio (CER) was calculated and plotted as a function of Gd concentration. The results were compared between the pulse sequences, and between the contrast media as well. Both 3DFLASH and 3DVIBE showed higher CER than other two sequences, showing similar CER curve configuration. There was no significant difference both in CER value and CER curve configuration between the two contrast media for each pulse sequence.     

Detection of Mason-Pfizer monkey virus infection by syncytia formation of human cells doubly transformed by Rous sarcoma virus and simian virus 40

Summary Human cells doubly transformed by Rous sarcoma virus and SV40 (RSb cells) formed syncytia by cocultivation with Mason-Pfizer monkey virus (MPMV)-producing cells. This cell fusion was blocked by anti-MPMV serum indicating that the phenomenon is MPMV specific. The RSb cells were successfully used for MPMV infectivity assay in the same manner as KC cells.With 1 Figure     

Ontogeny of the murine Ig joining chain gene and protein

We used Northern blot analysis in order to investigate the ontogeny of the murine joining (J)-chain gene. No J-chain expression was detected in embryonic tissues, including liver, spleen and intestine, but an expression of mu heavy chain was detected in foetal liver at day 17. J-chain expression was detected in the spleen at day 9 and in the intestine at day 15 after birth. Western blot analysis was carried out in order to compare the protein levels of J and mu heavy chains in serum from day 8 to day 24 after birth, using antihuman J chain and antimouse mu chain antibodies. Although mu chain protein could be detected in serum from day 8, J-chain protein was detectable only at day 24. These results suggest that the expression of J chain is a later event than the mu chain in the mouse, which thus differs in embryogenesis from humans.     

Electron-dense deposition patterns and the outcomes of idiopathic membranous nephropathy in Japanese

A considerable diversity in prognosis is seen with membranous nephropathy (MN). In terms of pathological findings, the presence of tubulointerstitial lesions was emphasized as a poor prognostic factor. However, the glomerular factors affecting the long-term outcome of idiopathic human MN have remained unclear. We reviewed the initial clinicopathological factors affecting the primary and secondary outcomes in 105 patients with primary MN, as well as reviewing previous reports. Based on electron microscopic (EM) findings, we could divide patients into two subtypes and one subgroup; i.e., homogeneous type with a synchronous phase of electron-dense deposits, with large dense deposits (deep subgroup) and heterogeneous type with various phases of dense deposits. The homogeneous type showed no endstage renal failure, and had earlier remission as compared with the heterogeneous type. For the secondary outcome, heterogeneous type and deep subgroup were also independent risk factors. However, there was no significant difference in the final primary or secondary outcome for any treatment subgroups. These results indicated that our category of EM findings was a beneficial marker of the primary and secondary outcomes in MN; the homogeneous type of MN with synchronous phase of electron-dense deposits (except for the "deep" subgroup) had a good outcome.     

Studies on complement-potentiated neutralizing antibodies (C'-PNAb) induced in rabbits inoculated with japanese encephalitis virus (JEV). I. The nature of C'-PNAb

The C'-PNAb induced by JEV grown in porcine kidney stable (PS) cells [JEV(PS)] inactivate not only the corresponding virus, hut also Western equine encephalitis (WEE), Eastern equine encephalitis (EEE), vesicular stomatitis (VS) and Sindbis viruses grown in PS cells or primary hamster kidney (HK) cell cultures in the presence of complement. The degree of complement-potentiated neutralizing (C'-PN) ability varies for each virus. The C'-PNAb do not, inactivate these viruses grown in mouse brain, even JEV. The C'-PN activity against viruses other than JEV(PS) is completely removed by absorption with the microsomal fraction of PS or HK cells, but not of mouse brain. The antibodies in fraction IgM induced by the microsomal fraction of PS or HK cells inactivate the viruses grown in PS cells to a different degree in the presence of complement, but not viruses grown in mouse brain. The activity of C'-PNAb against JEV(PS) is reduced to 2% of the original activity by absorption with sheep red cells. After absorption, the remaining C'-PNAb are not further reduced by absorption with the microsomal fraction of PS cells, nor do they inactivate the other viruses grown on PS cells. The early rabbit hemagglutination-inhibition (HI) antibodies in fraction IgM induced by JEV(PS) could not only inhibit hemagglutination with JE, WEE, EEE, and Sindbis viruses grown on PS cells in the absence of complement, but could also facilitate HI in the presence of complement. However, they could not inhibit hemagglutination with these viruses grown in mouse brain, in the presence or absence of complement. This activity of HI could also be removed by absorption with the microsomal fraction of PS cells. These findings suggest that C'-PNAb are induced by host cell components associated with the virus, and that the early HI antibodies in fraction IgM are the same entities as C'-PNAb.     

p38 Mitogen-activated protein kinase activation in endothelial cell is implicated in cell alignment and elongation induced by fluid shear stress.

Fluid shear stress is thought to be important in maintaining the phenotype of endothelial cells (ECs) in vivo. The purpose of the study was to determine the effect of varying levels of laminar shear stress on EC elongation and alignment and the role of p38 mitogen-activated protein kinase (MAPK) on the morphologic change induced by shear stress. Cultured bovine aortic ECs were subjected to 1, 4, 7, 14, or 20 dyne/cm(2) laminar steady shear stress. On morphometric analysis of static ECs, the average orientation angle was 41 degrees , whereas after 24 h shear stress at 1, 4, 7, 14, and 20 dyne/cm(2) the angles were 34 degrees, 33 degrees, 16 degrees, 11 degrees, and 10 degrees, respectively. The shape index of static ECs was 0.76, whereas the indexes of ECs exposed to shear stress were 0.72, 0.72, 0.65, 0.50, and 0.47, respectively. The time and the magnitude of activation of p38 MAPK were dependent on the level of shear stress. The results indicate that a minimum shear stress of 7 to 14 dynes/cm(2) is necessary for cell alignment and elongation and this correlates with activity of p38 MAPK. ECs exposed to shear stress in the presence of the p38 MAPK inhibitor SB-203580 did not orient in any manner and the shape index was similar to the static cells.     

Multiple epithelial cysts of the spleen and on the splenic capsule, and high serum levels of CA19-9, CA125 and soluble IL-2 receptor

An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts.     

Anaplastic Ependymoma of the Spinal Cord in Childhood A Case Report

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cere-brospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.     

Clinical effect of hypoallergenic rice (HRS-1) in atopic dermatitis. HRS-1 Research Group

The usefulness of hypoallergenic rice (HRS-1) was clinically evaluated in 43 patients with severe atopic dermatitis (AD), who were suspected of having rice allergy, in collaboration with 13 hospitals. The patients were fed with HRS-1 instead of eliminating both regular rice and wheat from their daily diet. AD area and severity index (ADASI) was calculated as an indicator of the degree of cutaneous symptoms. Significant decrease of ADASI were observed in the 2nd and 4th week and at the end of the replacement therapy (5.6 weeks on average). On final evaluation, 74% of the patients tested showed "moderate" to "remarkable" improvement, and in 53% of the patients HRS-1 resulted in a "moderate" to "remarkable" reduction in the dosage and the grade of potency of the steroid ointment concomitantly used for the treatment. Finally, HRS-1 was evaluated as "useful" to "very useful" as the elimination diet in 70% of the patients.