Cystine transport and glutathione metabolism in human erythrocytes

Cystine was transported into human erythrocytes in the presence of tertiary-butyl hydroperoxide (t-BH) or 1-chloro-2, 4-dinitrobenzene (CDNB). The transport rate of cystine was dependent on the extracellular concentration of t-BH or CDNB, and on the incubation time. By Dowex-1 column chromatography, the transported cystine was incorporated into fractions of glutathione disulfide (GSSG) and glutathione-S (GSH-S) conjugate. Cystine was also transported into reconstituted erythrocyte ghost with GSSG. The transport of cystine was Na+ dependent and decreased in the presence of N-ethylmaleimide, and it was competitively inhibited by DL-homocystine and L-alanine. The inhibition rates by DL-homocystine and L-alanine were 75% and 68%, with similar Ki values of 0.7 mM and 0.6 mM, respectively. The Km value for cystine transport was 0.15 mM. The activity of GSH-cystine transhydrogenase was detected in the hemolysate and this enzyme is thought to catalyze the action of incorporation of cystine into GSH. This enzyme was partially purified from normal human erythrocytes. In the presence of CDNB, similar rates of cystine transport were observed among the diabetic patients (n = 11), hypoxemic patients (n = 10) and the control subjects (n = 20). It is suggested that cystine transport is induced for glutathione synthesis when human erythrocytes are exposed to oxidative stresses.     

The investigation of isoflurane therapy for status asthmaticus patients]

Status asthmaticus is defined as an attack of bronchial asthma that resists conventional treatment and continues for more than 24 hours. We report here about patients with status asthmaticus who were successfully treated with isoflurane inhalation. Of the 19 patients who were transferred to the intensive care unit (ICU) and underwent mechanical ventilation from January 1996 to May 2001, eleven patients who were first treated by isoflurane inhalation were targeted in this study. Their improvement was assessed 6 and 24 hours after anesthesia compared with their condition before anesthesia. The tidal volume, pH, and PaCO2 improved within 6 hours after anesthesia. For the next step, among the patients who were transferred to the critical care center soon after an attack of bronchial asthma and underwent mechanical ventilation, 8 patients who were treated by isoflurane inhalation anesthesia (Group I) and another 4 patients who were not treated by isoflurane (Group NI) were compared to assess the usefulness of isoflurane inhalation therapy. The patients in Group I stayed in the ICU and underwent mechanical ventilation for a shorter period. These patients had hypotension and liver dysfunction after the inhalation anesthesia, but these symptoms were improved by decreasing the concentration of isoflurane. Isoflurane inhalation therapy seemed useful for intractable status asthmaticus, and earlier introduction of this therapy is expected to achieve a greater therapeutic effect.     

Construction of Canine Herpesvirus Vector Expressing Foreign Genes Using a lacZ-TK Gene Cassette as a Double Selectional Marker

An improved method for constructing canine herpesvirus (CHV) recombinants expressing foreign genes by using the lacZ-TK gene cassette as a double selectional marker was developed. A recombinant CHV carrying the lacZ-TK gene at a targeted gene locus was constructed and used as a parental virus for generating new recombinants. The parental virus formed blue plaques and was sensitive to TK-specific drugs, while newly generated recombinants, in which the lacZ-TK gene was replaced with the desired foreign gene, become both resistant to the TK-specific drugs and formed white plaques. Recombinants were isolated by using the combination of drug selection and color selection. This improved method allows construction of recombinant CHV with great ease, because the drug selection can enrich the frequency of recombinant CHV from 0.01–0.1% to 10–80%. This method was employed to construct a recombinant CHV that expressed rabies virus (RV) glycoprotein (G protein). This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of participatory workplace improvement program on stress-related biomarkers and self-reported stress among university hospital nurses: a preliminary study

Although participatory workplace improvement programs are known to provide favorable effects on high stress occupations like nursing, no studies have confirmed its effect using biomarkers. The aim of this study was to determine whether a participatory workplace improvement program would decrease stress-related symptoms as evaluated by biomarkers and self-reported stress among hospital nurses. Three actions to alleviate job stress, which were determined through focus group interviews and voting, were undertaken for two months. A total of 31 female Japanese nurses underwent measurement of inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) at three-time points; before the program (T1), within a week after the completion of the program (T2), and three months after the program (T3). A series of inflammatory markers (Interferon-γ, Interleukin (IL)-6, and IL-12/23p40) decreased significantly at T2, and IL-12/23p40 and IL-15 significantly decreased at T3 compared to T1, while ANA and PJS remained unchanged. Our participatory program exerted beneficial effects in reducing inflammatory responses, but not for ANA and PJS. Further investigations with a better study design, i.e., a randomized controlled trial, and a larger sample size are warranted to determine what exerted beneficial effects on inflammatory markers and why other outcomes remained unchanged.     

Radioimmunodetection of cancer of gastrointestinal tract and liver metastasis with I-131 anti-CEA and I-131 anti-CA19-9 monoclonal antibody cocktail (IMACIS-1)

We evaluated the intravenous infusion of a cocktail of I-131 anti-CEA and anti-C A19-9 monoclonal antibody F(ab’)2 (IMACIS-1) in patients with gastrointestinal neoplasm and liver metastases in order to assess its efficacy in detecting the presence of cancer. Seven patients with primary or recurrent gastrointestinal cancer in whom liver metastases were also detected were studied. Accumulation of radioactivity in the primary tumor was seen in only one patient. Visualization of the liver metastases was achieved in all patients. Thus detection of liver metastasis was better than in primary or recurrent tumors. While tumor visualization was most often seen in the 3 day image, optimal visualization of the tumor was seen at 5–7 days. There was no correlation between the serum concentration of CEA or CA19-9 and the visualization of tumors. Serum kinetics of I-131IMACIS-1 showed biexponential components with a 1st phase T_1/2 of 5.0 hours and 2nd phase T_1/2 of 34.7 hours. The mean whole body (I-131) half-life determined from the whole-body scans was 1.95 days. The mean urinary excretion of I-131 in 7 days was 85%. This value agreed closely with total radioactivity retention detected by scanning. This series of studies demonstrated the potential utility of a cocktail of antibodies consisting of an anti-CEA and an anti-CA19-9 monoclonal F(ab’)₂.     

Development of a simple method for the washout correction of 123I-IMP SPECT and its application to a quantitative rCBF method

We have developed a simple method to correct the washout of tracer from the brain based on the two-compartment model in brain early SPECT using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). This correction was applied to a new quantitative method of regional cerebral blood flow (rCBF) in combination with the microsphere method by continuous arterial sampling previously reported. Data acquisition of 123I-IMP early SPECT was started from 35 min after 123I-IMP i.v. injection, and the time activity curve of whole brain on anterior head planar images was monitored immediately after 123I-IMP i.v. injection for the correction of washout of tracer from the brain. The usefulness of this method was evaluated in 12 patients with various brain diseases by comparison with the results obtained from the super-early SPECT at 7-10 min after 123I-IMP i.v. injection. The washout rates in cases of early SPECT corrected by this method ranged from 16.91% to 39.34% with a mean +/- SD of 27.72 +/- 5.44%. The contrast of hypo- to hyperperfusion regions on early SPECT was improved by the correction of the washout, and its intracerebral distribution was similar to the simultaneously obtained super-early SPECT images. These results indicated that the present correction method for the washout was useful for more correct quantification of rCBF.     

Pure apraxic agraphia with abnormal writing stroke sequences: report of a Japanese patient with a left superior parietal haemorrhage

A 67 year old Japanese male patient had pure agraphia after a haemorrhage in the left superior parietal lobule. He developed difficulty in letter formation but showed no linguistic errors, consistent with the criteria of apraxic agraphia. He manifested a selective disorder of sequencing writing strokes, although he was able to orally state the correct sequences. The patient's complete recovery after 1 month, without new learning, showed that he had manifested a selective disorder of writing stroke sequences. These findings indicate that the final stage of the execution of writing according to acquired sequential memory shown as a stroke sequence can be selectively disturbed, and should be considered to be distinct from the ability of character imagery and the knowledge of the writing stroke sequence itself. This case also indicates that the left superior parietal lobule plays an important part in the execution of writing.     

Endothelin antagonist treatment for successful liver transplantation from non-heart-beating donors

BACKGROUND: With the shortage of cadaveric donors, non-heart-beating donors (NHBDs) are a potential source of liver allografts. However, warm ischemic injury in NHBDs seriously affects the viability of graft liver. Endothelin (ET)-1 has been reported to be involved in the hepatic microcirculatory disturbances after ischemia-reperfusion. METHODS: In a porcine orthotopic liver transplantation model, changes in the serum and liver tissue ET-1 concentration were measured and the effects of an ET receptor antagonist, TAK-044, were evaluated. After cardiac arrest of the donors, liver allografts were subjected to 90 min of warm ischemia, flushed, and preserved for 4 hr at 4 degrees C. The pigs were divided into two groups: a control group (no drug treatment) and a drug-treated group, in which donors and recipients were treated with TAK-044 (10 mg/kg body, drip intravenous injection). Both groups had six donor/recipient pairs. RESULTS: -The ET-1 concentration in the hepatic venous blood increased after reperfusion of the graft in the control group recipients. ET-1 in the graft liver significantly increased during the cold preservation period. TAK-044 treatment significantly increased recipient 7-day survival rate. After reperfusion of the graft, the concentrations of serum liver enzymes and arterial lactate in the drug-treated group were significantly lower than in the control group. The postoperative increase in portal venous pressure was significantly reduced in the drug-treated group. Measurements of liver enzymes in the washed-out preservation fluid at the time of graft rinsing indicated that TAK-044 treatment of the donors significantly suppressed liver enzyme release during ischemia. CONCLUSIONS: These findings indicate TAK-044 treatment has protective effects on postoperative function of hepatic allografts procured from NHBDs.