All-optical digital-to-analog conversion using pulse pattern recognition based on optical correlation processing

We propose and demonstrate a novel all-optical digital-to-analog (D/A) conversion using pulse pattern recognition based on optical correlation processing. It is composed of pulse pattern recognition based on correlation processing and intensity adjustment using an optical attenuator. We obtain a single pulse as a result of pulse pattern recognition by using correlation processing between a target digital signal and a prepared correlation filter function. The obtained single pulse can be promptly fed to an output port as a corresponding analog signal through adequate intensity adjustment. Experimental results show that four-bit digital signals with 1.65ps interval can be successfully converted to analog signals corresponding to input digital signals.

High hRFI expression correlates with resistance to fluoropyrimidines in human colon cancer cell lines and in xenografts

We previously reported that the over-expression of hRFI, a protein preferentially expressed in the digestive tract regions of several cancers, exhibited a tendency to inhibit TNF-alpha induced apoptosis. In this study, we sought to determine the potential effect of hRFI expression on the sensitivity to 5-fluorouracil (5-FU) and/or other fluoropyrimidines. For the whole lysates of 8 colon cancer cell lines, we performed Western blotting with anti-hRFI antibody and analyzed the correlations between the expression level of hRFI and the cell lines' sensitivity to 5-FU induced apoptosis. Furthermore, for a tissue microarray consisting of 32 xenograft derived human cancer cell lines, we examined the expression levels of hRFI and survivin by immunohistochemical staining, and analyzed the correlations between the expression of each protein and the sensitivity to several chemotherapeutic agents in the xenografts examined. Both in colon cancer cell lines and in xenografts, the expression level of hRFI was correlated with resistance to 5-FU and its derivatives. This evidence suggests that hRFI may be a marker predicting the response to fluorouracil derived chemotherapeutic agents and that the reduction of the expression level of hRFI might improve the outcome of chemotherapy.

Long-term treatment of generalised myasthenia gravis with FK506 (tacrolimus)

Efficacy and safety of long term use of FK506 (2-4.5 mg/day) for a maximum of two years were evaluated in 12 patients with generalised myasthenia gravis (MG). At the end of the study, eight patients (67%) showed improvement in either MG score or Activities in Daily Living score, and prednisolone dosage could be reduced in seven patients (58%), with a mean reduction ratio of 37%. Long term use of FK506 for MG can be more effective than short term administration, with no serious side effects.

Effect of tacrolimus in a patient with pure red-cell aplasia

A 78-year-old woman has suffered from pure red-cell aplasia (PRCA) associated with generalized myasthenia gravis and thymoma. Cyclosporin A (CyA) with corticosteroid increased numbers of erythroid cells in her bone marrow cells but she required monthly blood transfusions. Administration of tacrolimus as a substitution for CyA inhibited progression of anemia without the need for further blood transfusion. No serious side effects were observed. This case demonstrates that tacrolimus is another option of treatment for PRCA in patients who fail to respond to CyA.

Effects of expression of hRFI on adenoma formation and tumor progression in colorectal adenoma-carcinoma sequence

For colorectal carcinomas as well as colonic polyps we investigated the expression of a newly discovered gene, hRFI, which is isolated by the yeast two-hybrid screening using hTid as a bait and expressed highly in esophageal carcinomas. Immunohistochemical staining was performed on 48 colorectal carcinomas and 77 colorectal polyps consisting of 70 adenomas and 7 hyperplastic polyps using the antibody of hRFI. We analyzed the expression of hRFI and the correlation between the percentage of staining of each and their clinico-pathological characteristics. Protein coding by hRFI was specifically and diffusely expressed in most of the cancerous regions of the colorectum. Also, in the early stage of colorectal adenomas, staining of hRFI was focal, and the percentage area of diffuse staining increased as the degree of dysplasia progressed. Although all normal colorectal glands and most hyperplastic polyps (71.4%) showed no staining of hRFI, most colorectal adenomas and carcinomas (93.2%) showed a focal or diffuse staining (P<0.001). Furthermore, the percentage of diffuse staining in carcinomas (81.3%) was significantly higher than in adenomas (5.7%) (P<0.001). hRFI is highly expressed in colorectal carcinomas. In the adenoma-carcinoma sequence, hRFI is involved at the initial tumor formation and its diffuse expression is associated with colorectal carcinogenesis. This evidence suggests that hRFI may act as an oncogenic molecule affecting the apoptotic pathway.

[Reduction of preparatory bank blood requirements in adult cardiac surgery]

The importance of blood conservation to minimize homologous blood use in cardiac surgery is well-accepted. In addition, it is financially important to minimize unnecessary and avoidable bank blood prepared, because once the blood products were taken into a hospital, it could not be returned to the blood bank in Japan. We tried to safely reduce the amount of bank blood products requested in 185 consecutive adult cardiac operations for 18 months. First 6 months' observation revealed that only 2 patients received blood transfusion among 34 patients whose products of weight (kg) and hemoglobin (g/dl) were more than 700. We called the product "a transfusion index", and the amounts of blood prepared were newly set as follows: a transfusion index less than 500; 6 units or more of cross-matched red cell concentrate, 500-700; 2 to 4 units of cross-matched red cell concentrate, more than 700; no cross-matched bank blood. In next 6 months, the amounts of cross-matched blood reduced from 4.8 units to 3.9 units per patient. Last 6 months, we prepared no blood products for the patients whose transfusion indexes were more than 700. The amounts of prepared red cell concentrate reduced to 2.1 units per patient, however, additional blood requirements during the operations did not show significant increase. A transfusion index depends on the patient's weight and preoperative hemoglobin is a simple and useful indicator to anticipate blood requirements.

Type I interferon receptor and response to interferon therapy in chronic hepatitis C patients: a prospective study

The type I interferon (IFN) receptor consists of at least two subunits, IFNAR1 and IFNAR2. We previously found a correlation between IFNAR1 and IFNAR2 expression in liver, and a correlation in IFNAR2 expression, but not in IFNAR1, between liver and peripheral blood mononuclear cells (PBMCs). The aim of this study was to prospectively assess whether IFNAR2 expression levels in PBMCs as well as in liver act as markers for predicting response to IFN therapy in chronic hepatitis C patients. Fifty-two Japanese patients with chronic hepatitis C, were enrolled. IFNAR2 mRNA was quantified using competitive polymerase chain reaction, in liver and PBMC specimens, and of the 52 patients assigned to receive a 6-month course of interferon-alpha therapy, 36 patients who received more than 300 million units of interferon were analysed. IFNAR2 mRNA expression levels were significantly higher in liver than in PBMCs in all 36 patients (P = 0.016). Seventeen sustained virologic responders showed lower pretreatment hepatitis C virus (HCV)-RNA levels (P = 0.017) in serum and higher pretreatment levels of IFNAR2 mRNA in liver (P = 0.007), but not in PBMCs, compared with nonsustained virologic responders. In multivariate analysis, these factors were independently associated with a sustained virologic response (i.e. HCV-RNA level: odds ratio 0.23, 95% CI 0.038-0.864; and IFNAR2 in liver: odds ratio 1.116, 95% CI 1.015-1.227). Hence, IFNAR2 expression levels in liver, but not in PBMCs, is predictive of response to IFN treatment in chronic hepatitis C patients.

Association of histochemical expression of Maackia amurensis leukoagglutinin-positive glycoconjugates with behaviour of human gastric cancer

AIMS

To investigate the relationship between sialylation of glycoconjugates and clinicopathological characteristics of gastric cancer.

METHODS AND RESULTS

Sialylation of glycoconjugates was examined histochemically in 71 gastric cancers using Maackia amurensis leukoagglutinin (MAL), a lectin that recognizes the trisaccharide sequence NeuAc alpha 2,3Gal beta 1,4GlcNAc/Glc. Positive staining with MAL was observed in the tumour region of all of the samples, but the populations of MAL-positive tumour cells in the tumour region varied among the samples. In the corresponding non-cancerous regions, however, no positive staining was observed. Calculating the percentage of MAL-positive tumour cells as part of the total tumour cells with respect to the MAL-staining index (MI) allowed the gastric cancer to be classified into two distinct groups: high and low levels of MI, with a cut-off level of 40% of MI. Furthermore, statistical analyses using the MI level and clinicopathological characteristics of the tumour indicated that a high MI level in gastric tumour tissues is related to a poorer prognosis.

CONCLUSIONS

The appearance of MAL-positive glycoconjugates in gastric tumour cells is associated with the behaviour of gastric cancer.

Evaluation of factors influencing diffusion of pollutant loads in urban highway runoff

Many studies have identified the first flush phenomenon and runoff characteristics. The purpose of this study is to elucidate which parameters influence the runoff pollutant loads. Eight runoff events during the period from May 1999 to September 2000 were investigated. From the dimensionless cumulative analysis, it was suggested that particulate substances such as suspended solids (SS), iron and total phosphorus (T-P) were inclined to be washed off in heavier rainfall condition. The cumulative curves of particulate constituents were appreciably variable in slope, while those of dissolved were approximately constant. Accordingly it was indicated that dissolved load was discharged regardless of rainfall conditions. Event mean runoff intensity and cumulative runoff height showed significant correlation with the cumulative runoff load of the constituents except for total nitrogen (T-N). On the other hand, antecedent dry weather period (ADWP) and traffic flow volume during ADWP did not show correlation with the cumulative runoff loads. Only T-N load showed correlation with those factors, consequently it was suggested that vehicular exhausts affected nitrogen load on the surface of urban highway.

Secretion of natriuretic peptides caused by an epileptic attack

OBJECTIVE

To describe clinical features of a patient with secretions of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) during an epileptic attack.

PATIENT

A 65-year-old woman experienced frequent bouts of polyuria, pyrexia and general fatigue after several years of a cerebral contusion involving the left fronto-temporal lobe caused by a traffic accident. Her urine output and urinary sodium excretion increased, and plasma ANP and BNP concentrations were markedly high during each attack. Electroencephalography (EEG) showed serial seizure discharge in the left anterior temporal region during the attacks, indicative of epileptic focus.

CONCLUSION

ANP and BNP secretions probably were triggered by epileptic stimulation on the diencephalon beyond the focus.

Interferon retreatment reduces or delays the incidence of hepatocellular carcinoma in patients with chronic hepatitis C

Inhibition of hepatocarcinogenesis is a crucial issue in treating chronic hepatitis C patients, especially those who do not respond completely to interferon therapy. Interferon has been reported to reduce the incidence of hepatocellular carcinoma (HCC) not only in sustained virological responders but also in transient biochemical responders. However, the incidence of HCC increases in 5 years or more after interferon therapy in transient biochemical responders. The aim of this study is to assess whether interferon retreatment reduces the incidence of HCC in chronic hepatitis C patients in whom hepatitis C virus was not eradicated during initial interferon therapy. We enrolled 309 patients who were not sustained virological responders after initial interferon treatment consisting of a total dose of more than 250 megaunits of interferon and were followed for more than 2 years after treatment. Ninety-nine patients received interferon retreatment and 210 did not. Two courses of interferon therapy were administered in 84, three courses in 14 and five courses in one. The incidence of HCC was compared between patients with retreatment and those without. In the clinical characteristics, retreated patients were younger and followed up for a longer time period. The cumulative incidence of HCC was significantly lower in retreated patients. In multivariate analysis, patients' age (P=0.018) and the number of courses of interferon therapy (P=0.022) were independently associated with HCC incidence. These results suggest that interferon retreatment reduces or delays the incidence of HCC in chronic hepatitis C patients who did not completely respond to initial therapy.

Two-Dimensional Image Transmission Based on the Ultrafast Optical Data Format Conversion between a Temporal Signal and a Two-Dimensional Spatial Signal

We have experimentally demonstrated a two-dimensional (2-D) image transmission based on the ultrafast optical data format conversion between a temporal signal and a spatial signal with an ultrashort optical pulse. In the proposed system we adopt a spectral holography technique to transmit a one-dimensional (1-D) spatial signal and use a spatial-domain time-frequency transform to realize a transform between 1-D and 2-D spatial signals. By use of these techniques, a low-optical-loss transmission system can be constructed. To demonstrate a 2-D image transmission with this technique, we achieved experimentally transmission of the alphabet letter T as a 3 x 3 pixel 2-D spatial image.

Anti-tumor-promoting activity of the diterpene from Excoecaria agallocha. II

Eight new diterpenoids (1-8) have been isolated from the wood of Excoecaria agallocha (Euphorbiaceae) and their inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) in Raji cells were examined to search for potent anti-tumor-promoters from natural resources. Of these compounds, the secolabdane-type diterpenoid, compound 7 exhibited a remarkable inhibitory effect on EBV-EA induction, and a significant anti-tumor-promoting effect in the mouse two-stage carcinogenesis test using 7,12-dimethylbenz[a]anthracene and 12-O-tetradecanovl-phorbol-13-acetate.

A novel emulsifier, labrasol, enhances gastrointestinal absorption of gentamicin

Gentamicin (GM) is an important aminoglycoside antibiotic for the treatment of infections caused by a wide spectrum of aerobic gram-negative bacilli and gram-positive cocci. As a class, the aminoglycosides are poorly absorbed from the gastrointestinal (GI) tract and are commonly used as injectable and topical preparations. This study was aimed at finding the effect of a novel emulsifier, Labrasol, on the absorption of GM from the GI tract of rats. GM formulations were prepared, either as saline solution or as Labrasol microemulsions, and were administrated to rat small intestine and colon. Plasma GM levels following intestinal application were compared to those obtained with intravenous (i.v.) administration. A 5 mg/kg dose of GM preparation containing Labrasol, 1 ml/kg, administrated into colon resulted in the mean AUC of 21.179+/-1.374 microg x h/ml, compared to 7.813+/-0.105 microg x h /ml obtained with i.v. administration of GM, 1 mg/kg. The absolute bioavailability (BA) of the Labrasol preparation was 54.2%. Labrasol facilitates the transmucosal delivery of GM from rat colon by forming microemulsions, and the BA obtained with Labrasol microemulsion was higher than with other surfactants (8.4% for Tween 80 and 3.4% for Transcutol P). Additionally, in vitro permeation studies demonstrated that Labrasol also inhibited the intestinal secretory transport. The effect of Labrasol is ascribed to both (1) enhanced GM absorption from the GI lumen into the systemic circulation and (2) inhibition of efflux of GM from the enterocytes to the GI lumen.