Effects of chitosan-coated dialdehyde cellulose, a newly developed oral adsorbent, on glomerulonephritis induced by anti-Thy-1 antibody in rats

The effects of chitosan-coated dialdehyde cellulose (chitosan DAC), a newly developed oral adsorbent for urea and ammonia, were examined in a glomerulonephritis model in rats. Mesangial proliferative glomerulonephritis accompanied with proteinuria was induced by an intravenous injection of anti-rat Thy-1.1 monoclonal antibody (OX-7). The proliferation of mesangial cells and an accumulation of extracellular matrix components such as type I collagen and fibronectin were observed in the glomeruli 9 days after OX-7 injection; these were improved in rats fed a diet containing chitosan DAC (10% content) for 9 days compared with those in rats fed a normal diet. Chitosan DAC treatment decreased the elevated urinary protein and blood urea nitrogen at days 8-9 to the normal levels; the increased fecal excretion of nitrogen might participate in this phenomenon. In addition, chitosan DAC treatment showed an increase in fecal water content associated with a decrease in urinary volume. These therapeutic effects may be due to the reduction of proteinic factor expression and the compensational function of chitosan DAC for kidney. These results suggest that chitosan DAC treatment may be useful for ameliorating mesangial proliferative glomerulonephritis.

Effects of abdominal belts on intra-abdominal pressure, intra-muscular pressure in the erector spinae muscles and myoelectrical activities of trunk muscles

OBJECTIVE

To evaluate the effects of abdominal belts on lifting performance, muscle activation, intra-abdominal pressure and intra-muscular pressure of the erector spinae muscles.

DESIGN

Simultaneous measurement of intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles was performed during the Valsalva maneuver and some isometric lift exertions.

BACKGROUND

While several hypotheses have been suggested regarding the biomechanics of belts and performance has been found to increase when lifting with belts, very little is known about the modulating effects on trunk stiffness. At present, there is no reason to believe that spine tolerance to loads increases with belts.

METHODS

An abdominal belt designed for weightlifting was used. Intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles and myoelectric activities of trunk muscles (erector spinae, rectus abdominis and external oblique) were measured simultaneously during the Valsalva maneuver as well as three types of isometric lifting exertions (arm, leg and torso lift). A paired t-test was used to analyze for statistical differences between the two conditions (without-belt and with-belt) in intra-abdominal pressure, intra-muscular pressure of the erector spinae muscles and in the integrated EMG of the trunk muscles.

RESULTS

Intra-muscular pressure of the erector spinae muscles increased significantly by wearing the abdominal belt during Valsalva maneuvers and during maximum isometric lifting exertions, while maximum isometric lifting capacity and peak intra-abdominal pressure were not affected. Integrated EMG of rectus abdominis increased significantly by wearing the abdominal belt during Valsalva maneuvers (after full inspiration) and during isometric leg lifting.

CONCLUSIONS

Wearing abdominal belts raises intra-muscular pressure of the erector spinae muscles and appears to stiffen the trunk. Assuming that increased intra-muscular pressure of the erector spinae muscles stabilizes the lumbar spine, wearing abdominal belts may contribute to the stabilization during lifting exertions.

Beneficial effects of a novel inhibitor of platelet-derived growth factor receptor autophosphorylation in the rat with mesangial proliferative glomerulonephritis

1. Our original compound, Ki6896 ((4-t-butylphenyl)(4-[(6,7-dimethoxy-4-quinolyl) oxy]phenyl) methanone) strongly inhibited the autophosphorylation of platelet-derived growth factor (PDGF) beta-receptor (IC50=0.31 microM) and that of basic fibroblast growth factor receptor (IC50=3.1 microM), whereas it did not inhibit some other kinases. 2. The [3H]thymidine incorporation and the growth of mesangial cells under the stimulation of PDGF were inhibited by Ki6896 in a dose-dependent manner. 3. In the mesangial proliferative glomerulonephritis rats induced by anti-Thy-1 monoclonal antibody, glomerulosclerosis was ameliorated and the number of glomerular proliferating cells was decreased by the daily administration of Ki6896. However, the accumulation of type I collagen and fibronectin in the glomeruli was not suppressed by Ki6896.

Meniscal cyst in the posterior intercondylar space found by magnetic resonance imaging

We report a rare case of meniscal cyst from the posterior horn of the lateral meniscus, extending in the posterior intercondylar space of the right knee of a 15-year-old boy, in whom magnetic resonance imaging was very useful for evaluation. A cyst in this location has not been reported previously. The cyst was removed surgically, while preserving the lateral meniscus. A good result was obtained, and no recurrence has been seen in 12 months.

Selective inhibition of platelet-derived growth factor (PDGF) receptor autophosphorylation and PDGF-mediated cellular events by a quinoline derivative

This report describes the biological effects of our original compound, Ki6783 ((3,4-dimethoxy)-4-phenoxy-6,7-dimethoxyquinoline), a potent and selective inhibitor of platelet-derived growth factor (PDGF) receptor autophosphorylation. This compound strongly inhibited autophosphorylation of the PDGF beta-receptor in cultured rat glomerular mesangial cells (MC) bearing this receptor (IC50 0.1 microM), although it did not inhibit autophosphorylation of other growth factor receptors even at 100 microM. In a cell-free kinase experiment, it showed selective inhibition of PDGF beta-receptor tyrosine kinase. A kinetic study of the compound to this tyrosine kinase revealed a competitive mode of action to ATP. [3H]Thymidine incorporation and cell proliferation of MC were inhibited by Ki6783 in a dose-dependent manner after Ki6783 and PDGF-BB were added to the culture medium. Furthermore, this compound normalized the fibrotic cell shape of v-sis-transformed NIH3T3 cells, which grow in an autocrine manner via the PDGF receptor. These effects could be explained by the inhibition of intracellular signal transduction triggered by PDGF receptor autophosphorylation, in which activation of mitogen-activated protein kinase occurs. These results suggest that Ki6783 is one of the more potent and selective inhibitors of PDGF receptor autophosphorylation and that it may be useful in ameliorating cell abnormalities due to excess action of PDGF and its receptor systems in several diseases.

[Necrotizing fasciitis due to invasive group A streptococcal infection: a case report]

Necrotizing fasciitis is a relatively rare but potentially fatal soft tissue infection. We report a case of invasive group A streptococcal necrotizing fasciitis. Patient was a 55-year-old healthy male who presented an expanding suppurative lesion over the left lower extremity within one day. Streptococcus pyogenes was a sole microorganism isolated from the infection site. The key to successful treatment in this case was suggested to be early diagnosis combined with aggressive debridement followed by open drainage and high dose administrations of piperacillin before complications such as liver dysfunction and renal failure became serious.

Factors influencing yield of plateletpheresis by discontinuous centrifugation

Plateletphereses performed by the Haemonetics Model 30 Blood Processor under a fixed condition were retrospectively analyzed. The mean platelet yield was 5.97 X l0 (ll) (+/- l.46 X l0 (ll). Prepheresis platelet count was significantly correlated to platelet yield (p less than 0.001), but hematocrit was not (p greater than 0.1). Blood-drawing time showed a significant correlation (p less than 0.01) and may suggest than an infusion rate of 60 ml/minute is a technique of choice. A large number of platelets (% platelet recovery = 73.0 +/- l4.l%) was discarded in order to remove erythrocytes and leukocytes from the initial product. The recovery was negatively correlated to the percentage removal of leukocytes (p less than 0.01), which means that a platelet product of good quality not containing leukocytes can be prepared at the sacrifice of a large quantity of platelets. It is desirable to devise a simple and practical technique to obtain pure platelets without loss.

Vasovagal reactions in blood donors

The donor records of a hospital blood bank, analyzed from a statistical standpoint demonstrated a low incidence of vasovagal reactions: 119 in 10,547 donations (1.13%). Donors of younger age and of lower diastolic blood pressure were more prone to reaction. There was no significant sex difference. Higher reaction rates were also associated with first-time donation, the time of year (spring), and a particular phlebotomist. The low reaction rate and the clearly demonstrated psychologic factors in the present study were attributed to a reflection of the small amount (200 ml) of blood withdrawn. The importance of the phlebotomist-donor relationship was stressed.