Five percent, 7.5% or 10% hypertonic saline prevents delayed neuronal death in gerbils

PURPOSE: To clarify the appropriate concentration and dose of hypertonic saline solution (HSS) for preventing delayed neuronal death in the hippocampal CA1 subfield after transient forebrain ischemia in gerbils. METHODS: Thirty gerbils were randomly assigned to five groups: physiological saline solution (PSS) group, ischemia/reperfusion treated with PSS 2 mL x kg(-1); 5% HSS group, treated with 5% HSS 2 mL x kg(-1); 7.5% HSS group, treated with 7.5% HSS 2 mL x kg(-1); 10% HSS group, treated with 10% HSS 2 mL x kg(-1); 20% HSS group, treated with 20% HSS 2 mL x kg(-1). Transient forebrain ischemia was induced by occluding the bilateral common carotid arteries for four minutes. Five days later, histopathological changes in the hippocampal area were examined, and the degenerative ratio of the pyramidal cells were measured according to the following formula: (number of degenerative pyramidal cells/total number of pyramidal cells per 1 mm of hippocampal CA1 subfield) x 100. RESULTS: In PSS and 20% groups, neuronal cell damage was observed five days after ischemia. In the other three groups, these changes were not observed. The degenerative ratios of pyramidal cells were as follows; PSS group: 91.6 +/- 5.6%, 5% HSS group: 7.2 +/- 1.6%, 7.5% group: 8.3 +/- 1.4%, 10% HSS group: 6.2 +/- 1.1%, 20% HSS group: 85.8 +/- 8.7% (P < 0.05; PSS and 20% HSS vs three other groups). CONCLUSION: This study demonstrates that 5, 7.5 or 10% HSS 2 mL x kg(-1) may prevent delayed neuronal death in the hippocampal CA1 subfield after cerebral ischemia/reperfusion in gerbils.     

Clinical effects of oxybutynin hydrochloride (Pollakis)--especially in the treatment of pollakisuria, urgency and urinary incontinence

The effects and the safety of oxybutynin hydrochloride were investigated in 52 patients, 17 male and 35 female, with the chief complaints of pollakisuria, urgency and urinary incontinence. Clinical responses to the drug were assessed mainly by the subjective symptoms of the patients. The diagnoses of these patients were neurogenic bladder in 17, unstable bladder in 16 and others in 19 patients. The average administration period was 66.8 days. The rate of global improvement (excellent and good) was 55% in the 2 mg dose given 3 times daily group, 68.2% in the 3 mg dose given 3 times daily group. Side effects, such as dry mouth, were observed in 2 of the 52 patients (3.8%), but no serious side effects were observed. The rate of global utility (remarkable and moderate) was 67.3%. These data indicate that oxybutynin hydrochloride seems to be useful and safe for the treatment of pollakisuria, urgency and urinary incontinence.     

The effects of potassium concentration in reperfusion solution upon myocardial protection]

The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage.     

Prevention of Acute Lung Allograft Rejection in Rat by CTLA4Ig

CTLA4 immunoglobulin (CTLA4Ig), which binds with a high affinity to B7-1 and B7-2, interrupts T-cell activation by inhibiting costimulatory signal. CTLA4Ig has been used in hopes of achieving antigen-specific tolerance induction in several solid organ transplants. In lung allograft rejection, however, its use has been controversial in terms of its effect on prevention of rejection. In the present study, the effect of murine CTLA4Ig on rat-lung allograft rejection was investigated. Rat left-lung transplantation was performed in an RT1 incompatible donor (Brown Norway; BN)-recipient (F344) combination. All allografts (n = 12) without any treatment were rejected within 7 days after transplantation. A single injection of murine form CTLA41g at a dose of 100 microg intraperitoneally (ip) or intravenously (iv) on day 1 post-transplantation achieved long-term graft survival (>90days) in 2/5 (40%) and 3/8 (38%), respectively. Moreover, 6/7 (86%) allografts in rats that received iv injection of 500 microg CTLA4Ig survived more than 90days. Allograft survival in the CTLA4Ig 500 microg iv recipient group was significantly longer than that in the no-treatment control or control immunoglobulin group (p <0.01). Four out of seven recipients bearing functional allografts for more than 90 days with the CTLA4Ig treatment accepted donor-specific skin grafts, whereas all third-party skin grafts (n=3) were rejected. Prevention of rat-lung allograft rejection could be achieved by intravenous administration of CTLA4Ig, resulting in long-term allograft survival with acceptance of donor-specific skin grafts.     

Effects of dexamethasone on the expression of myelin basic protein, proteolipid protein, and glial fibrillary acidic protein genes in developing rat brain.

Effects of dexamethasone (DEX) on the relative abundance of myelin basic protein (MBP), proteolipid protein (PLP) and glial fibrillary acidic protein (GFAP) mRNAs in the developing rat brain were examined. After DEX (1.0 mg/kg body weight) or saline was administered intraperitoneally to 3-day-old rats for 7 consecutive days, wet weight, DNA content and the relative abundance of the glia-specific mRNAs in cerebrum and cerebellum were analyzed at postnatal days (P) 10, 20 and 30. DEX decreased both wet weight and DNA content in cerebellum more profoundly than in cerebrum. The appearance of MBP, PLP and GFAP mRNAs in cerebellum preceded that in cerebrum in the control group. In cerebrum, the relative abundance of MBP and PLP mRNAs was significantly less in the DEX group than that in the control group at P20 and P30. The relative abundance of the GFAP mRNA was significantly less in the DEX group than in the control group at P10 and P20, but there was no significant difference at P30. In cerebellum, a significant decrease in the abundance of MBP, PLP and GFAP mRNAs in the DEX group was observed only at P10 but not at P20 and P30. Our findings indicate that DEX suppresses expression of genes related to glial functions, especially myelination when administered in the early postnatal period.