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.     

Studies on isolated smooth muscle cells. IX. Application of papain for isolation of single smooth muscle cells from guinea-pig taenia coli

To prepare single smooth muscle cells from the taenia coli of guinea pig, the application of papain to the enzymatic solution was examined under two conditions: 1) the isolation in a modified Tyrode solution (containing 0.18 mM Ca2+: 0.18 mM Ca2+-Tyrode solution) and 2) the isolation in a high-K+ Tyrode solution (Na+ was replaced by K+, and Ca2+ was not added: high-K+ Tyrode solution). The presence of papain during collagenase digestion reduced contamination of broken cells and cell debris. In the case of the high-K+ Tyrode solution, papain increased the yield of single cells significantly. The cells were contracted in a dose-dependent manner by Ca2+ in the high-K+ Tyrode solution and by carbachol in 0.18 mM Ca2+-Tyrode solution; furthermore, the contractions were antagonized by verapamil and atropine, respectively. Treatment with papain did not affect cell sensitivity to the stimulants. Therefore, our results suggest that the addition of papain is useful for the isolation of single cells to investigate the physiological and pharmacological characteristics of smooth muscle.     

A case of secondary bladder tumor the origin (gastric cancer) of which could not be identified before autopsy

Primary bladder tumor is the most frequent malignant tumor in the field of urology, whereas the incidence of secondary bladder tumor from a distant organ is quite rare. We report here a 21-year-old female patient with metastatic bladder tumor from gastric cancer. She came to our hospital with a complaint of only bladder irritability. Cystoscopical and cytological examinations revealed rhabdomyosarcoma of the bladder. She did not respond to radiation therapy and combined chemotherapy, consisting of actinomycin D, vincristine and cyclophosphamide, and died 91 days after admission. Autopsy revealed a primary tumor of poorly differentiated scirrhus carcinoma of the stomach. Thus this was a quite rare case of metastatic bladder carcinoma characterized by bladder irritability without gastrointestinal symptoms.     

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.     

A new method for monitoring the cerebrovascular response to acetazolamide using 99mTc-DTPA-HSA.

We developed a new method for monitoring the cerebrovascular response to acetazolamide using technetium-99m diethylenetriaminepentaacetic acid human serum albumin (99mTc-DTPA-HSA). We infused 740 M Bq (20 mCi) of 99mTc-DTPA-HSA intravenously and carried out dynamic scanning of the anterior view of the head for 50 minutes. Ten minutes after the start of scanning, 1,000 mg of acetazolamide was injected intravenously. In three normal volunteers, the radioactivity in brain increased for an average of 8 minutes after the injection of acetazolamide and then remained relatively stable. The average of dilatation index [(peak count/the count just before acetazolamide injection-1)x 100] was 16.1. Our method enabled us to observe vasodilation caused by acetazolamide straight, and may be of value in assessing cerebral perfusion reserve easily and quantitatively.     

Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood--mainly in vitro]

Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood was studied mainly in vitro. When 99mTc-ECD was mixed with blood taken from 12 subjects, the octanol extraction ratio of ECD (y) decreased rapidly and the octanol extraction ratio-time profile well fitted a monoexponential curve (y = Ae-kt/1000, A, k: constant, t: time after mixing). The k value and hematocrit (Ht) were significantly correlated (k = 0.376Ht-3.27, r = 0.897, p less than 0.001), therefore, it was suggested that the majority of the enzyme which dissolves ECD exists in red blood cells. When ECD was mixed with blood, there were more hydrophilic products of ECD in plasma than those generated by the enzyme in plasma. In vivo input function of 99mTc-ECD was calculated by arterial blood sampling and octanol extraction. The duration of effective input was relatively short, which was attributed to rapid decrease of octanol extraction ratio in vivo.     

Testicular descent. III. The neonatal mouse gubernaculum shows rhythmic contraction in organ culture in response to calcitonin gene-related peptide.

The effects of calcitonin gene-related peptide (CGRP) and CGRP 8-37 on the neonatal mouse gubernaculum were examined in organ culture, with the aim of seeing whether CGRP has a direct effect on the gubernaculum. A total of 440 gubernacula were studied. Two hundred and fifty gubernacula were treated with CGRP in concentrations ranging from 0-714 nM/liter. With increasing doses of CGRP the percentage of gubernacula showing vigorous contraction increased from 18-50%. The total percentage of gubernacula showing any form of contraction increased from 76-96%. One hundred and fifty gubernacula were exposed to the CGRP analog CGRP 8-37. Increasing concentrations of CGRP 8-37 from 179-714 nM/liter decreased the rate of vigorous contraction from 18-4%. The percentage of gubernacula showing any degree of contraction decreased from 76-14%. Forty gubernacula removed from testicular feminization (TFM) mice were exposed to varying concentrations of CGRP. In the absence of exogenous CGRP no contractility was observed. By contrast, in the presence of CGRP the gubernacula showed vigorous contractility increasing from 38-90%. The total number of gubernacula showing contraction increased from 75-100%. These studies demonstrated that the neonatal mouse gubernaculum exhibits a high level of endogenous contractility, which can be enhanced in a dose responsive manner with exogenous CGRP. CGRP 8-37 caused a dose responsive inhibition. The androgen-insensitive gubernaculum from the TFM mouse showed no endogenous contraction, but on exposure to CGRP showed an enhanced rate of contractility. These results are consistent with the hypothesis that androgens may control gubernacular migration indirectly via release of CGRP from the genitofemoral nerve in the inguinoscrotal region. The failure of gubernacular motility in vitro and migration in vivo in the TFM mouse may indicate lack of CGRP release from the genitofemoral nerve.