Increased expression of mRNAs for microtubule disassembly molecules during nerve regeneration

The mRNA expression of the microtubule disassembly molecules (SCG10, stathmin, SCLIP and RB3) in response to nerve injury was examined using a rat hypoglossal nerve injury model. After nerve injury prominent increase in mRNA expression of SCG10, stathmin and RB3 was observed, while only slight increase in SCLIP mRNA was observed in injured motor neurons. The increase in SCG10 and RB3 mRNA expression was quicker than that of stathmin and SCLIP. All the elevated signals decreased gradually to control levels by 4 weeks after nerve injury.     

Immediate early genes and p21 regulation in liver of rats with acute hepatic failure

It has been observed that liver regeneration in acute hepatic failure (AHF) is suppressed [Eguchi et al. Hepatology 1996;24(6):1452-9]. The molecular mechanism regulating this inhibition is not known. We previously reported that in AHF rats, hepatocyte proliferation was significantly impaired with elevation in serum IL-6, TGF-beta1, and HGF [Kamohara et al. Biochem Biophys Res Commun 2000;273(1):129-35]. Following either 70% partial hepatectomy (PH) or liver injury, quiescent mature hepatocytes are "primed" to re-enter the cell cycle. The process of "priming" appears to be triggered by extracellular cytokines (IL-6 and TNF-alpha) and is characterized by expression of immediate early genes. Under the stimulation of growth factors such as HGF, "primed" hepatocytes exit the G1 phase of the cell cycle. G1-associated cyclins and their inhibitors play a pivotal role in G1/S cell cycle transition. Here, we demonstrate that immediate early gene (i.e. c-myc, c-fos) expression and AP-1 activity are preserved in AHF rat livers despite absence of hepatocyte proliferation. In contrast, p21 mRNA and protein are both over-expressed in AHF livers compared to livers from rats undergoing PH; this elevation leads to inhibition in Cdk2 activity, resulting in G1 cell cycle arrest and inhibition of regeneration.     

Suppression of cellular immunity in men with a past history of posttraumatic stress disorder

OBJECTIVE: High rates of medical morbidity have been reported in subjects with posttraumatic stress disorder (PTSD). The authors examined immune function in subjects in remission from past PTSD. METHOD: The initial study group was composed of 1,550 Japanese male workers. Japanese versions of the Events Check List, the Impact of Event Scale-Revised, and the Diagnostic Interview Schedule for DSM-IV were used to identify subjects who had a past history of PTSD. Twelve of the workers were identified as having such a history. These men were matched in age and smoking habits, which affect immunity, to 48 comparison subjects who had similar stressful life experiences but no current or past history of PTSD. Natural killer (NK) cell activity, lymphocyte subset counts, and production of interferon gamma (IFN-gamma) and interleukin-4 (IL-4) were measured in the 60 men by means of phytohemagglutinin stimulation. RESULTS: The number of lymphocytes, number of T cells, NK cell activity, and total amounts of IFN-gamma and IL-4 were significantly lower in the 12 men with a past history of PTSD. CONCLUSIONS: PTSD leaves a long-lasting immunosuppression and has long-term implications for health.     

Membrane-associated Lymphotoxin Expression and Functional Analysis of Lymphokine-activated Killer Cells Derived from Tumor-infiltrating Lymphocytes

The expression of a membrane-associated lymphotoxin molecule (mLT) on lymphokine-activated killer (LAK) cells obtained from 18 patients with malignant tumors and its role in the tumor cell killing mechanisms were investigated. LAK cells from tumor-infiltrating lymphocytes (TIL-LAK cells) were mainly composed of CD3-positive cells, whereas LAK cells from peripheral blood lymphocytes (PBL-LAK cells) were mainly composed of CD16- and CD56-positive cells. However, mLT was found to be expressed on TIL-LAK cells as well as PBL-LAK cells. The degree of mLT expression correlated with the killing activity of LAK cells towards L929 cells (r=0.806, P <0.01, n = 15), but not with that towards Daudi or K562 cells. Although the degree of mLT expression correlated with the amount of secreted lymphotoxin (LT) in the supernatant of LAK cell culture, the secreted LT itself could not account for the tumor cell killing activity of LAK cells. Polyclonal rabbit anti-LT antibody partially inhibited the killing activities of LAK cells towards L929 cells and this inhibition was found in the combination of autologous tumor cells and PBL-LAK cells. These findings suggest the possibility that the mLT-related cytotoxicity is involved in the tumor cell killing mechanisms of TIL-LAK cells as well as PBL-LAK cells.     

Low-dose GnRH agonist therapy for the management of endometriosis.

OBJECTIVE: In order to examine whether treatment with a GnRH agonist alone can maintain estrogen levels within the "estrogen window" that inhibits endometriosis without influencing bone-mineral density, we studied the effects of GnRH agonist therapy and changes in bone-mineral density. METHODS: Buserelin acetate nasal spray was administered 3 times a day for 8 weeks (daily dose, 900 micrograms) to 21 women with endometriosis. The drug was then given twice a day for 16 weeks (daily dose, 600 micrograms). The total duration of treatment was 24 weeks. The bone-mineral density of the lumbar vertebrae was measured by dual-energy X-ray absorptiometry before treatment (baseline), at the end of treatment, and 24 weeks after the end of treatment. RESULTS: The bone-mineral density of the lumbar vertebrae at the end of treatment was 2.44% +/- 0.46% (mean +/- standard error) lower than the baseline value. The value at 24 weeks after the end of treatment was 1.10% +/- 0.64% lower than the baseline value. More than 80% of the patients had serum-estradiol levels of 45 pg/ml or less. During treatment, more than 90% of the patients had serum-estradiol levels of 60 pg/ml or less. Genital bleeding was inhibited in 90% of the patients. After 8 weeks of treatment, the clinical symptoms improved in 75% of the patients; such improvement persisted for the duration of the treatment. CONCLUSION: Decreasing the dose of GnRH agonist during treatment can minimize the loss of bone-mineral density without lessening the beneficial effects on endometriosis. This technique might be useful in the management of endometriosis.     

Effects of immunosuppressants on induction of regulatory cells after intratracheal delivery of alloantigen

BACKGROUND: We previously reported that intratracheal delivery (ITD) of alloantigen generated regulatory cells in mice. Here, we examined the effect of various doses of conventional immunosuppressants (FK506, cyclosporine A, azathioprine, mycophenolate mofetil, and rapamycin) on inducing regulatory cells in our model. METHODS: CBA mice (primary recipients) were given C57BL/6 splenocytes by ITD and either no additional treatment or various doses of an immunosuppressant. Seven days later, splenocytes from these mice were adoptively transferred into naive secondary CBA recipients that underwent C57BL/6 cardiac grafting the same day. RESULTS: Adoptive transfer from primary recipients given ITD of splenocytes alone induced prolonged allograft survival in secondary recipients (median survival time [MST], 50 days), suggesting that regulatory cells were generated. When ITD of alloantigen was combined with daily administration of 0.1 mg/kg FK506 or 0.2 mg/kg rapamycin, graft survival was similarly prolonged (MST 55 and 50 days, respectively). When combined with 20 or 40 mg/kg MMF or 0.4 mg/kg rapamycin, the majority of recipients demonstrated indefinite survival (MST, >100 days in all groups). When ITD of alloantigen was combined with 0.3, 0.5, or 1.0 mg/kg FK506; 5, 10, or 25 mg/kg cyclosporine A; or 1.0 or 2.0 mg/kg azathioprine, allografts were rejected acutely (MST 7-13 days). CONCLUSION: Generation of regulatory cells by ITD of alloantigen was facilitated by mycophenolate mofetil and high doses of rapamycin but abrogated by cyclosporine A, azathioprine, and high doses of FK506. Low doses of rapamycin and of FK506 did not interfere with generation of regulatory cells.     

Prestin-dependent and prestin-independent motility of guinea pig outer hair cells

The motile response of isolated guinea pig outer hair cells (OHCs) was investigated using a combination of whole-cell patch clamp recording and continuous video image analysis. OHC's length, width, and area were measured from video images and the cell volume estimated from these values. Morphological data was then correlated with electrophysiological recordings of whole-cell current, membrane potential and voltage-dependent non-linear capacitance. Electromotility was evoked either by manipulating the membrane potential under voltage-clamp conditions or by exposing OHCs to high K+ solutions. Other motile responses were investigated in voltage-clamp experiments at constant holding potential, or exposing OHCs to solutions that did not affect the membrane potential. We found that electrical stimulation evoked voltage-dependent changes in OHC's length, width and area but not in cell volume regardless of the time course of stimulation. Moreover, changes in cell area were always associated with both voltage-dependent motility and non-linear capacitance, suggesting prestin dependency. In contrast, voltage-independent motile responses at constant membrane potential, which are presumed to be prestin-independent, were associated with changes in cell length, width and volume without significant changes in area. Area measurements, then, become a tool to investigate the simultaneous occurrence of both prestin-dependent and prestin-independent OHC motilities, and for evaluating the individual contribution of each mechanism to the total cell movement.