Correlation between semaphorin3A-induced facilitation of axonal transport and local activation of a translation initiation factor eukaryotic translation initiation factor 4E

An impressive body of evidence has been accumulated indicating that local protein synthesis is implicated in navigation of neurite extension induced by guidance cues, such as semaphorin3A (Sema3A). We found previously that a Src type tyrosine kinase Fyn and cyclin-dependent kinase 5 (Cdk5) mediate Sema3A-signaling. We also showed that Sema3A elicits axonal transport through neuropilin-1, a receptor for Sema3A, located at the growth cones. Here, we investigate the relationship between Sema3A-induced local signaling, protein synthesis, and axonal transport. Lavendustin A, a tyrosine kinase inhibitor, and olomoucine, a cyclin-dependent kinase inhibitor, suppressed Sema3A-induced facilitation of anterograde and retrograde axonal transport in dorsal root ganglion (DRG) neuron with and without the cell body. Sema3A-induced facilitation of axonal transport was attenuated in DRG neurons of fyn- (fyn-/-) and a Cdk5 activator, p35 (p35-/-)-deficient mice when compared with those of wild-type or heterozygous mice. Inhibition of protein synthesis suppressed Sema3A-induced facilitation of axonal transport in the DRG neuron with and without the cell body. Sema3A enhanced the level of immunoreactivity of phosphorylated eukaryotic translation initiation factor 4E (eIF-4E) within 5 min in growth cones in a time course similar to that of the facilitated axonal transport. This enhanced signal for phospho-eIF4E was blocked by lavendustin A or olomoucine and was not detected in the fyn-/- and p35-/- neurons. These results provide evidence for a mutual regulatory mechanism between local protein synthesis and axonal transport.

Basic and clinical studies on ApoE gene typing by line probe assay (LiPA) as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan

The fundamental reagent capability and clinical significance of ApoE gene typing has been investigated. The result of each test shows that the reagent capability satisfied the expected standard. Four-hundred thirty-nine samples classified into three groups (Alzheimer's disease (AD), other types of dementia and nondementia) were measured to examine the clinical significance. The rate of epsilon 4 genotype of each group was 31.5%, 14.6%, 10.4%, respectively. The AD group had a higher rate than the other groups (p < 0.001). The measurement of ApoE genotype is suggested to be useful as one of the guidelines in the diagnosis of AD.

Basic and clinical studies on the measurement of tau protein in cerebrospinal fluid as a biological marker for Alzheimer's disease and related disorders: multicenter study in Japan

The development of a diagnostic marker for earlier and more accurate clinical diagnosis of Alzheimer's disease (AD) is essential to identify AD patients during life unequivocally. The purpose of this study was to investigate the basic performance and clinical significance of tau level measurement in the cerebrospinal fluid (CSF) using an enzyme-linked immunosorbent assay (ELISA) developed by Innogenetics. The ELISA system showed reliable reproducibility and good linearity. For clinical studies, the CSF samples from a variety of patients (n = 332) were examined. They were classified into the four groups: Alzheimer's disease (AD); neurodegenerative disease (ND); cerebrovascular diseases (VD); and a neurological control (NC) group. The CSF-tau levels for AD, ND, VD and NC were 426 +/- 234 pg/ml, 239 +/- 157 pg/ml, 216 +/- 136 pg/ml, and 188 +/- 103 pg/ml, respectively. The CSF-tau level of the AD group was significantly higher than that of the other groups (p < 0.001). The CSF-tau levels increased during follow-up. The measurement of the tau level in CSF is shown to be a useful marker to confirm a clinical diagnosis of AD.

Development of a fogless scope and its analysis using infrared radiation pyrometer

BACKGROUND

In laparoscopic surgery, fogging of the lens tip instantly degrades the quality of image and interrupts the flow of surgical maneuvers. External warming devices prevent fogging for a certain length of time, but use of them is troublesome at best. These problems prompted us to develop a fogless mechanism built into the scope so that the fogless image would be continuous and trouble-free. We then conducted several experiments that demonstrate the precise effect it has on the lens tip.

METHODS

The infrared radiation pyrometer was used to compare the temperature distribution as well as the temperature change against time of each lens tip of the fogless and ordinary laparoscopes.

RESULTS

The temperature of the lens tip of the ordinary scope did not change, but that of the fogless scope rose to 41 degrees C in 184-208 s.

CONCLUSIONS

The fogless mechanism effectively warms the lens tip to a safe temperature that prevents fogging in the intraabdominal environment.

Functional integrity of hepatocyte canalicular membrane transport of taurocholate and bilirubin diglucuronide in Eisai hyperbilirubinuria rats

Eisai hyperbilirubinuria rats (EHBR) are characterized by conjugated hyperbilirubinemia, and impaired or defective excretion of bilirubin, reduced glutathione and other organic anions from hepatocytes. Hepatocyte canalicular membrane vesicles (CMV) from EHBR and normal SD rats were studied with regard to taurocholate (TC) transport driven by ATP or a membrane potential and bicarbonate-stimulated bilirubin diglucuronide (BDG) transport. ATP-dependent uptake or association of BDG with CMV was also studied in both strains of rats. No significant differences in the uptake of TC and BDG by CMV were observed. This indicates the functional integrity of the canalicular transporters for both organic anions in EHBR. Biliary excretion of taurolithocholic acid sulfate (TLCS) is defective in EHBR. However, TLCS inhibited ATP-dependent TC uptake by SD rat CMV competitively, which may be against the hypothesis that a common organic anion carrier is defective in canalicular membranes of jaundiced rats.

Bilirubin diglucuronide transport by rat liver canalicular membrane vesicles: stimulation by bicarbonate ion

The purpose of this study was to provide further insight into the mechanism of bilirubin diglucuronide excretion through the hepatocyte canalicular membrane by investigating the uptake of (3H)bilirubin diglucuronide by purified canalicular membrane vesicles of rat liver. The uptake was analyzed by a rapid filtration technique. The difference between vesicle-associated (3H)bilirubin diglucuronide at 37 degrees C and at 0 degree C during the initial 1 min was regarded as uptake. Twenty second uptake was saturated by increasing the (3H)bilirubin diglucuronide concentration at a vesicle-inside-directed 100 mmol/L KCl gradient (Km = 75 mumol/L, Vmax = 320 pmol/mg protein.20 sec at 37 degrees C). No sodium dependency was observed. When canalicular membrane vesicles were preincubated with nonlabeled bilirubin diglucuronide, the uptake increased 1.3-fold (transstimulation). Vesicle-inside-positive potential induced by valinomycin and potassium caused a 1.4-fold increase in the uptake. When Cl- was replaced by equivalent ion concentrations of SO4(2-), HCO3-, NO3- and SCN-, the uptake was 78%, 244%, 68% and 50%, respectively, and specific stimulation by HCO3- was observed (Km = 75 mumol/L, Vmax = 700 pmol/mg protein.20 sec at a vesicle-inside-directed 100 mmol/L KHCO3 gradient at 37 degrees C). The uptake was inhibited in a dose-dependent manner by the addition of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid. The uptake was ATP independent. From these results, it was concluded that bilirubin diglucuronide transport through the canalicular membrane is carrier mediated, electrogenic and stimulated by HCO3-.

ATP-dependent taurocholate transport by rat liver canalicular membrane vesicles

We conducted an experimental study to examine the possibility that ATP is involved in the mechanism by which bile acids are excreted through the liver canalicular membrane in opposing the concentration gradient. Canalicular membrane vesicles were purified from the livers of Sprague-Dawley rats, and the uptake of tritiated sodium taurocholate into canalicular membrane vesicles was determined by rapid filtration technique. Vesicle-associated sodium taurocholate was increased in the presence of ATP and ATP-regenerating system. This was also observed at a voltage-clamped condition. ATP-dependent uptake into the osmotically reactive intravesicular space was saturated with increasing concentrations of sodium taurocholate (Km = 47 mumol/L, Vmax = 270 pmoles/mg protein.20s). ATP-dependent uptake increased to the point of saturation when the sodium taurocholate concentration was 50 mumol/L and the ATP concentration was increased from 0 to 1 mmol/L (Km = 64 mumol/L). Among the several nucleotides used, ATP was a potent stimulator of transport, whereas a nonhydrolyzable analogue (i.e., adenosine 5'-[beta,gamma-imino]triphosphate) showed no effect. In addition, ATP-dependent transport was inhibited by vanadate in a dose-dependent manner. From these results it was concluded that the primary active transport of sodium taurocholate is present in hepatocellular canalicular membranes. This transport is directly dependent on ATP, and hydrolysis of gamma-phosphate of ATP is required.

[A study of drinking habits of rural middle and old aged residents in Ibaraki Prefecture--relationship between problem drinking, depression and personality (Part 1). On male subjects]

Although there has been considerable research conducted regarding the relationship between alcohol dependency and clinical depression, there have been few reports which have investigated the relationship between alcohol consumption and depression in the general populace of residents of rural communities in Japan. We investigated this correlation in a rural community located in Ibaraki Prefecture, the findings of which are described in this report. The subjects of this investigation were residents of the southern part of the town of K in Ibaraki Prefecture age 40 and over, all of whom had participated in a medical examination program. With respect to the men surveyed, the proportions of problem drinkers and severe problem drinkers were 10.4% and 25.7%, respectively. According to the results we obtained with respect to correlation with personality, problem drinkers were found most frequently in shut-in personality types (37.5%). In regard to the correlation with depression, 7% of the problem drinkers and severe problem drinkers exhibited an SDS score of 50 or higher. In addition, the non-drinking group demonstrated a significantly higher degree of depression in comparison to the normal drinker and severe problem drinker groups.

[Analysis of cerebellar functions in spinocerebellar degeneration using positron emission tomography (PET)]

We quantitatively evaluated the cerebellar functions of 23 patients with spinocerebellar degeneration (SCD) and 10 normal controls using positron emission tomography (PET). Statistical analysis was performed using the Student's test. Regional cerebral blood flow (CBF) and regional cerebral metabolic rate (CMR) of the cerebellar hemisphere and cerebellar vermis were significantly lower in patients with SCD than in normal subjects (p less than 0.001). However, no significant difference between the both groups was seen in the CBFs and the CMRs of the occipital cortex and frontal cortex. Even in the patients with SCD who had not apparent cerebellar atrophy on CT, their CBFs and CMRs of the cerebellum were significantly low, and with advance of cerebellar atrophy, they tended to fall. In the patients with SCD, the fall of CMR was more prominent than that of CBF. Neither CBF, nor CMR of the cerebellum showed correlation to the duration of the illness. The present investigation suggested that PETs were valuable for the early diagnosis and the research on the pathogenesis of SCD.