[Detection of GBV-C RNA among non B non C hepatocellular carcinoma patients]

Recently, an RNA virus member of the flaviviridae, GBVirus C(GBV-C) was isolated from the serum of patient with cryptogenic hepatitis, but clinical significance for this virus has been not known now. To estimate the prevalence of GBV-C, we investigated the presence of GBV-C RNA by reverse transcription-nested polymerase chain reaction in the serum from various liver disease patients. The results were summarized as follows: [Table: see text] Among these, only 5 patients gave positive results, and these 5 cases had the history of blood transfusion before. Especially both non B non C HCC patient and non A non B non C fulminant hepatitis patient were negative for GBV-C on admission, while positive after blood transfusion as treatment. In the non B non C HCC patient, GBV-C RNA persisted over a period of several months after transfusion, while no remarkable elevation of ALT was observed. These results demonstrated that GBV-C/HGV may be transfusion-transmissible, and may not associated with severe chronic liver disease such as liver cirrhosis or HCC.

Effects of inhibition of myo-inositol transport on MDCK cells under hypertonic environment

To investigate the role of myo-inositol under hypertonic conditions, we examined the effects of inhibition of myo-inositol transport in Madin-Darby canine kidney (MDCK) cells using an analog of myo-inositol, 2-O,C-methylene-myo-inositol (MMI). We first characterized the inhibitory effects of MMI on myo-inositol transport in MDCK cells. The Na+-dependent component of [3H] myo-inositol uptake was inhibited by MMI in a concentration-dependent manner, although MMI did not inhibit the activities of the betaine transporter and system A neutral amino acid transporter. We found decreased affinity for myo-inositol in the presence of MMI, whereas the maximal velocity (Vmax) of the transporter did not change. Thus MMI behaves as a competitive inhibitor of myo-inositol transport with a relatively high inhibition constant (K(i)) value (1.6 mM). Myo-inositol content in hypertonic MDCK cells was markedly reduced in the presence of 5 mM MMI, but MMI itself did not accumulate in these cells. The hypertonic cells began to detach in the presence of MMI 3 days after increasing medium osmolality, whereas MMI did not affect the cells in isotonic medium. We also examined the effects of MMI on colony-forming efficiency of MDCK cells. MMI decreased colony-forming efficiency in a concentration-dependent manner, and addition of myo-inositol returned the efficiency to the value without MMI. Addition of betaine also increased colony-forming efficiency in the presence of MMI. These results indicate that myo-inositol plays an important role in survival and growth under hypertonic environment.

Expression of syndecan-1 and -3 during embryogenesis of the central nervous system in relation to binding with midkine

Midkine (MK) is a 13-kDa heparin-binding growth/differentiation factor, and its interaction with heparan sulfate proteoglycan is important in promotion of neurite outgrowth. This study was performed to reveal the species of syndecans that interact with MK during embryogenesis of the central nervous system in the rat. Northern blot analysis and immunohistochemical staining using antibodies to syndecans showed that syndecan-1 was strongly expressed in the brain and spinal cord of the 10-day rat fetus, and the expression became weak as embryogenesis proceeded. On the other hand, syndecan-3 expression was stronger both in the brain and spinal cord in the later developmental period (day 14-16 of gestation). No significant expression of ryudocan (syndecan-4) was detected in fetal brains by Northern blot analysis. Syndecan-3 isolated from 16-day rat fetus bound to MK strongly, as did syndecan-1 isolated from 10-day rat fetus. Thus, both syndecan-1 and syndecan-3 were considered to be involved in interaction with MK during construction of the central nervous system; syndecan-1 is expected to play important roles in the earlier periods, and syndecan-3 in the later periods.

Constituents of a fern, Diplazium subsinuatum. II. Structure elucidation of five new hopane-triterpene glycosides

From whole fern, Diplazium subsinuatum (Wall. ex Hook. et Grev.) Tagawa, two new hopane-triterpene glycosides named diplaziosides III and IV were isolated, together with three new hopane glycosides with acetylated sugars. The structures of diplaziosides III and IV were established as (22S)-24-O-alpha-L-arabinofuranosyl-(1 --> 2)- [beta-D-glucopyranosyl-(1 --> 6)]-beta-D-glucopyranosyl-20 alpha-O-beta-D-glucopyranosyl-30-hydroxyhopan-28-oic acid (1) and (22R)-24-O-alpha-L-arabinofuranosyl-(1-->2)-[beta-D-glucopyranosyl-(1--> 6)]-beta-D-glucopyranosyl-30-carboxy-17-hydroxy-hopano-28,22-lacto ne (2), respectively, on the basis of spectral evidence. Diplazioside III (1) is novel not only in its glycoside structure, but also in its triterpene structure and moreover, 1 provides the first instance of a naturally occurring bisdesmoside with a hopane aglycone. The structures (3a, 3b, and 4a) of the acetylated glycosides were also elucidated, and this is the first report of naturally occurring acetates of hopane glycosides.

[Isolation and structure elucidation of longshengensin A from Peucedanum longshengense]

Two compounds were isolated from Peucedanum longshengense Shan et Sheh for the first time. Their structures were identified as longshengensin A (I) and mannitol (II) by physico-chemical constants and spectral analyses (UV, IR, MS, NMR and 2D-NMR). I is a new compound with the structure of (-)-3' (s)-acetyloxy-4' (s)-angeloyloxy-3', 4'-dihydroseselin and named longshengensin A. Its absolute configurations were determined by chemical correlation with khellactone.

Renal angiotensin-converting enzyme localization in diabetic rats and the effect of low protein diet

Recent evidence suggests a role of angiotensin-converting enzyme (ACE) in diabetic nephropathy. The effect of diabetes and low protein diet on renal immunohistochemical ACE localization was studied in streptozotocin-induced DM rats. Immunohistochemical ACE localization was reduced in DM rats, and a low protein diet partially resolved this abnormality while inhibiting the progression of diabetic nephropathy.

Effect of acidosis on contraction, intracellular pH, and calcium in the newborn and adult rabbit aorta

This study investigated the effect of acidosis on intracellular pH (pHi), intracellular calcium concentration ([Ca]i), and vascular contraction in the aorta of the newborn and adult rabbit. Isometric tension, pHi, and [Ca]i were measured in an isolated ring preparation. After the vascular contraction was induced with 50mM KC1, the effect of respiratory acidosis produced by elevation of PCO2 was studied. Respiratory acidosis caused a transient depression followed by a recovery of contractile tension. The decrease in developed tension was greater in the newborn than in the adult. The decrease in pHi during acidosis was similar in the two age groups. [Ca]i increased during acidosis and the increase was greater in the newborn than in the adult. These data show that the vasorelaxant effect of acidosis in the newborn aorta is greater than that in the adult aorta. The greater vasodilation in the newborn cannot be explained by the difference in pHi or [Ca]i.

Antigen uptake and immune responses after immersion vaccination

Immersion vaccination is an effective and practical method for mass vaccination of fish and most commercial bacterins are currently administered by this method, even though the exact mechanisms of antigen uptake and protection still remain unknown. Immersion vaccination includes several delivery techniques including spray, direct immersion, hyperosmotic dip and flush exposure. Various factors have been shown to influence the uptake of antigen from a vaccine bath, such as the concentration of vaccine, the length of immersion time, size of the fish, stress, pH and salt concentration of the vaccine solution, the water temperature, anaesthetics, the use of adjuvants, and the physical state (particulate or soluble) of the antigen. Among these, the antigen concentration is the most important factor for antigen uptake and protection. Recently we found that the amount of antigen taken up is correlated with the length of immersion time in dilute vaccine solutions. Most authors have suggested the gills as the main site of antigen entry, but skin, lateral line and the gut have also been suggested. Our quantitative study has shown that the skin is the main site of antigen uptake and that there are no differences in rate of uptake between the lateral line and the remaining skin of the body surface. Not only phagocytes but also several types of epithelial cells are involved in antigen uptake. Cells involved in antigen uptake can be different depending on the physical state of the antigen and the site of antigen entry. In most trials with immersion vaccination, antibodies against pathogens are not detectable in the serum by micro-titration and, even when antibodies are found, the titre does not always correlate with protection. However, some authors have reported elevated specific antibody levels in the serum of fish vaccinated by immersion, and even that protection can be successfully conferred by transferring immune plasma. Thus, the role of humoral immunity on protection mechanisms after immersion vaccination has been controversial and potentially important roles for cell-mediated immunity or local immunity have been implicated.

Developmental changes in the contractile system of the mesenteric small artery of rabbit

This study investigated developmental changes in the contractile system of the mesenteric small arteries of the rabbit. Arteries about 1 mm in length and 100-250 microns in internal diameter were dissected out from the mesenteric bed of the fetus (29 d of gestation), newborn (3-5 d old), and adult rabbit. Vascular contraction was induced by high KCl concentration, and contractile force was measured using a tension transducer. The sensitivity of vascular contraction to high KCl was similar in the three age groups. To determine the role of Ca influx across the sarcolemma in vascular contraction, the vasorelaxant effect of diltiazem was studied in the artery precontracted with high KCl concentration. The vasorelaxant effect of diltiazem in the fetus and newborn was less than in the adult. To estimate the size of the intracellular Ca pool, caffeine-induced and noradrenaline-induced contraction were measured in the Ca- and Na-free solution. In the fetus and newborn, both the caffeine-induced contraction and noradrenaline-induced contraction were greater than in the adult. The ultrastructural study showed that the endoplasmic reticulum was abundant in the fetus and newborn, and it was scarce in the adult. These data indicate that the dependency of vascular contraction on Ca influx across the sarcolemma increases and the intracellular Ca store decreases with development in the mesenteric resistance arteries.

Evaluation of coronary artery stenoses using electron-beam CT and multiplanar reformation

PURPOSE

We assessed the diagnostic value of electron-beam CT with multiplanar reformation for coronary artery stenoses.

METHOD

Thirty-seven patients who underwent conventional coronary angiography were evaluated with ECG-triggered thin section electron-beam CT with intravenous contrast enhancement. Multiplanar reformation of a stack of the images was performed to visualize coronary arteries. Two observers blind to the results of conventional coronary angiography independently evaluated the reformatted images.

RESULTS

The sensitivity and specificity for the detection of significant lesions were 100 and 100% in the left main coronary artery, 83 and 84% in the left anterior descending artery, 67 and 96% in left circumflex artery, 63 and 79% in the right coronary artery, and 74 and 94% for total results, respectively. All false-positive results in the left anterior descending artery were caused by wall calcification, and in the right coronary artery, 83% of the false-positive results were caused by small slice gaps in noncalcified segments.

CONCLUSION

Electron-beam CT was feasible for the detection of coronary artery stenoses. For interpretation of reformatted images, calcification and slice gaps should be taken into consideration.

NaCl and/or urea infusion fails to increase renal inner medullary myo-inositol in protein-deprived rats

As we recently demonstrated that in potassium depletion a decrease in inner medullary organic osmolytes might precede and cause a renal concentrating defect, we hypothesized that in the protein deprivation the same mechanism may occur. To clarify the relationship between renal medullary organic osmolytes and urine concentration defects during protein deprivation, we examined the effect of protein malnutrition on organic osmolyte content after water deprivation or sodium and/or urea infusion. Water deprivation did not restore urine urea and osmolality or tissue sodium and urea in protein-deprived rats to control levels. NaCl infusion only increased urinary and medullary Na. Urea infusion increased medullary urea but not urine urea. NaCl plus urea infusion increased only urinary sodium and urea. Regardless of the protocols of hyperosmolality used, protein deprivation significantly decreased the medullary contents of myo-inositol and taurine and the level of sodium-dependent myo-inositol transporter mRNA. We conclude that factors other than NaCl and urea but associated with protein feeding are responsible for the decreased accumulation of organic osmolytes.

Comparative study of informal labor markets in the urbanization process: the Philippines and Thailand

"Culturally, socially, and politically, the Philippines and Thailand are completely different, but in the economic sphere until the end of the 1970s, the two exhibited such similarity that they could have been called twins. During the 1980s, however, the difference in the economic progress of the two countries widened greatly.... Relying on field surveys, this study will try to further clarify the differences in the social structures of the two countries through an analysis of the effects that urbanization has had on the urban informal labor market. Essentially it seeks to comprehend the urban labor market by approaching from another angle Hara's argument that the labor market in the Philippines is extremely segmented while that in Thailand is one of free movement between sectors with educational attainment effectively acting as a signal of labor quality."

Evaluation of the radiosensitizing effects of RK28 intravenous, intraarterial, and intratumoral injections on the rabbit VX2 tumor system

PURPOSE

To evaluate the differences in the radiosensitizing effects of intravenous (i.v.) injection, intraarterial (i.a.) injection, and intratumoral (i.t.) injections of the hypoxic cell radiosensitizer RK28 ([1-(4'-hydroxy-2'-butenoxy)methyl-2-nitroimidazole], a 2-nitroimidazole with an acyclic sugar analogue substituted at the N-1 position of the imidazole ring) using an animal experimental system.

METHODS AND MATERIALS

Rabbit VX2 tumors, which were implanted in the muscle of left hind legs and grown to 3 cm in diameter, were treated with RK28 (80 mg/kg x b.wt.) before 15 Gy of local x-ray irradiation. The auricular vein and the left saphenous artery were used for systemic injection and regional injection, respectively. For i.t. injection, a 21-gauge needle with three lateral holes was positioned in the central area of the tumor. Tumor regression was precisely evaluated by computed tomograpy (CT), and survival time was also studied. Using high-performance liquid chromatography (HPLC), pharmacokinetic studies for RK28 and its seven major metabolites were performed in tumor and serum at 0, 10, 20, 30, and 60 min after drug injection was completed.

RESULTS

Radiosensitizing effects of RK28 were considered present after i.a. injection (p < 0.05) and i.t. injection (p < 0.05) after analyzing tumor volumes on day 21 after treatment. Increased survival was not observed in any group with RK28 injection compared with survival in the group treated by x-ray irradiation alone. Pharmacokinetic studies showed the average concentration of RK28 in the tumor during x-ray irradiation was 1.3 times higher after i.a. injection and 3.5 times higher after i.t. injection than that after i.v. injection. The time modifying factor50 (TMF50: ratio of time for tumor to decrease by 50%, radiation alone vs. radiation plus drug) was calculated to be 1.5 after i.v. injection, 1.7 after i.a. injection, and 2.3 after i.t. injection. The values of TMF50 correlated to the average concentrations of RK28 in the tumor. As to metabolites of RK28, beta-glucuronated compound and cysteine conjugate were highly detected. The concentrations of cysteine conjugate were higher in the tumor than in serum via i.v. injection.

CONCLUSIONS

Radiosensitizing effects of RK28 were observed on the rabbit VX-2 tumor system after i.a. or i.t. injection. Pharmacokinetic studies proved that radiosensitizing effects depended on the concentration in the tumor, though the administration routes were different. Combined forms with nonprotein thiols were detected. However, survival benefits were not obtained by RK28. For clinical applications of RK28, i.a. or i.t. injection could facilitate better local control of cancer.

Telomerase in hepatocellular carcinogenesis

Despite the recent advances in diagnostic techniques of HCC, diagnosis of HCC is still difficult and ambiguous when HCC is small and of the well differentiated type. The results presented here demonstrated that strong telomerase activity was frequently detected in HCC irrespective of the stage or size of the nodules but neither in non-tumor diseased liver nor in normal liver. Telomerase activity determination can be a useful additional tool for the diagnosis of early well-differentiated HCC.

Autocrine mechanism of epidermal growth factor in choriocarcinoma cell proliferation

We examined four choriocarcinoma cell lines, NaUCC-1, NaUCC-3, NaUCC-4 and BeWo, for the presence of epidermal growth factor (EGF) by enzyme immunoassay and reverse transcription and polymerase chain reaction, and for EGF receptor (EGFR) by 125I-EGF binding assay. Specific EGF binding and EGF proteins were detected in these four choriocarcinoma cell lines. On the cell lines examined, NaUCC-4 had the greatest EGF binding capacity (18 x 10(5) sites/cell) and the highest amount of immunoreactive EGF (142 pg/ml). These results prompted us to assess the significance of EGF/EGFR autocrine mechanism in NaUCC-4 cells. Low doses of exogenous EGF stimulated 3H-thymidine incorporation, and monoclonal antibodies against EGF or EGFR dose-dependently inhibited 3H-thymidine incorporation. On the other hand, these antibodies did not significantly affect hCG production. These results suggested that EGF might function in an autocrine manner to stimulate proliferation rather than differentiation of NaUCC-4 choriocarcinoma cells.

Growth of the neopulmonary valve annulus after arterial switch operation in transposition of the great arteries

BACKGROUND

It is known that supravalvular pulmonary artery stenosis can occur in patients with d-transposition of the great arteries (TGA) after arterial switch operation (ASO). However, little is known about the growth of the neopulmonary valve annulus after the ASO. This study investigated the growth potential of the neopulmonary (old aortic) valve annulus.

METHODS AND RESULTS

Annular diameters of the old aortic and neopulmonary valve were measured from cineangiograms in patients who underwent cardiac catheterizations both before and > 1 year after the ASO. Of 71 patients, 13 (18%) had either a small annulus (< 70% of the expected normal value) or no significant growth of the neopulmonary annulus after the ASO, and 4 (6%) had a pressure gradient of > 30 mm Hg across the valve. The small annulus or no growth of the neopulmonary valve was more frequent in patients with a history of pulmonary artery banding. After the ASO, the valve diameter in patients with a ventricular septal defect was 80 +/- 15% of normal (n = 24), and the value was significantly less than in patients with an intact ventricular septum (91 +/- 11%, n = 47). In all patients with an intact ventricular septum who underwent the one-stage ASO, the valve diameters before and after the ASO were within normal limits, and a significant increase in the pulmonary valve annulus was observed.

CONCLUSIONS

These data indicate that not only supravalvular pulmonary stenosis but also pulmonary valvular stenosis due to a small annulus can occur in TGA, especially in patients with a history of pulmonary artery banding and in patients with ventricular septal defect.

Electrospray ionization-tandem mass spectrometry analysis of peptides derived by enzymatic digestion of oxidized globin subunits: An improved method to determine amino acid substitution in the hemoglobin "core"

The determination of an amino acid substitution in the "core" region of abnormal hemoglobin is technically difficult and is time- and labor-intensive both by conventional and by mass spectrometry techniques. Underivatized subunits cleaved with trypsin and lysyl endopeptidase were analyzed by high-performance liquid chromatography-electrospray ionizationmass spectrometry. The core peptides showed a series of multiply charged ions of homo- and heterodimers. Abnormal peptides in the core region could be detected in dimeric form. The sequence of core peptides was determined by product ion spectra of the peptides from oxidized globin digested with trypsin and lysyl endopeptidase. Oxidation of cysteine residues to cysteic acids in the core region resulted in the strong promotion of y-series ions by product ion analysis with a tryptic peptide from apoprotein B-100 as previously reported by Burlet, Yang, and Gaskell (J. Am. Soc. Mass Spectrom. 1992, 3, 337-344). These techniques were used to prove that substitution of an unstable hemoglobin, known as Hb Santa Ana (β88 leucine → proline), occurred in a patient with congenital hemolytic anemia. The tandem mass spectrometry analysis with oxidized globin digested with trypsin and lysyl endopeptidase offers a novel method to detect substitutions in the core region of hemoglobin.

A clinical study of direct pulp capping applied to carious-exposed pulps

Direct pulp capping of carious-exposed pulp was performed on 44 teeth. We evaluated the success rates of these cases, and analyzed the relationships between the success rates and their clinical findings. Furthermore, we examined the length of time necessary for adequate postoperative follow-up. The success rate in this study was 81.8%. Age of the patients, type of teeth, responses to thermal stimuli and percussion, and the diameter of pulpal exposure had no bearing on the success rate. However, the degree of bleeding on pulpal exposure was related to the success rate (p = 0.042). The success rates of cases in which postoperative follow-up periods were 3 to 18 months were similar (80 to 83%), whereas those with follow-up for 21 months (91.7%) and 24 months (100%) showed higher success rates. These results showed that direct pulp capping was applicable to carious-exposed pulp, and the degree of bleeding is indicative of the prognosis of this treatment. The length of time necessary for adequate postoperative follow-up was suggested to be 21 months.

[Usefulness of 99mTc-DTPA-HSA scintigraphy in the diagnosis of protein losing enteropathy--comparison with 99mTc-HSA]

We evaluated the usefulness of 99mTc-diethylene-triamine-pentaacetic acid human serum albumin scintigraphy (FTPA-HSA) in the diagnosis of protein losing enteropathy in 3 cases of inflammatory bowel diseases in comparison with 99mTc-human serum albumin scintigraphy (HSA). The results were as follows: 1. DTPA-HSA demonstrated the colonic accumulation earlier than that of HSA. 2. Hepatic flexure and splenic flexure are not observed clearly, because of marked renal uptake in HSA. On the other hand, they are observed in DTPA-HSA. Hepatic uptake is rather stronger in DTPA-HSA. In conclusion, DTPA-HSA is one of the easiest and most useful methods in the diagnosis of protein losing enteropathy.