[Mutagenicity studies of lactitol (NS-4)]

Lactitol (NS-4), a hepatic encephalopathy drug, was examined for mutagenicity in the reverse mutation test in bacteria, the chromosome aberration test with cultured mammalian cells, and the micronucleus test in mice. 1. In the reverse mutation test using Salmonella typhimurium (TA1535, TA100, TA1537, and TA98) and Escherichia coli (WP2uvrA), the drug did not significantly increase revertant colonies in any of the test strains with or without metabolic activation system (S-9mix). 2. In the chromosome aberration test with cultured Chinese hamster lung cells (CHL/IU), the drug did not significantly increase aberrant cells in the direct method or in the metabolic activation method. 3. In the micronucleus test with Slc:ddY male mice, the drug did not significantly increase micronucleated polychromatic erythrocytes in the bone marrows. These results suggest that lactitol has no mutagenicity in vitro or in vivo.

Role of the domain-domain interaction in the construction of the antigen combining site. A comparative study by 1H-15N shift correlation NMR spectroscopy of the Fv and Fab fragments of anti-dansyl mouse monoclonal antibody

A comparative NMR structural study of anti-dansyl Fv and Fab fragments is reported. Both of these antigen binding fragments have been prepared using antibodies that originate from the identical anti-dansyl switch variant cell lines. It has been confirmed that the Fv and Fab fragments possess the identical binding property. The antigen binding fragment analogs labeled with 15N of the main chain amide group of the aromatic residues (His, Phe, Trp, and Tyr) were used. The chemical shift and hydrogen-deuterium exchange rate of the amide protons are compared for the Fv and Fab fragments. On the basis of the NMR data obtained, we have concluded that (1) the structural change induced in the VH domain upon antigen binding significantly affects the dynamical structure of the VL domain and (2) the existence of the constant regions affects the fluctuation of the VL domain, increasing the thermal stability of the variable region.

Characteristics of the hepatocarcinogenesis caused by dehydroepiandrosterone, a peroxisome proliferator, in male F-344 rats

The characteristics of the hepatocarcinogenesis induced by dehydroepiandrosterone (DHEA) were compared with that induced by other peroxisome proliferators such as [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio]acetic acid (Wy-14,643) and di(2-ethylhexyl)phthalate (DEHP). Male F-344 rats were given a diet containing DHEA at 0.5 or 1%, Wy-14,643 at 0.1% and DEHP at 2% for up to 78 weeks. In rats fed 0.5 or 1% DHEA the incidence of neoplasias was 20% after 52 weeks. At 78 weeks all rats treated with 1% DHEA had numerous grossly visible nodules and the incidence of hepatic neoplasia was dose-dependent. The magnitude of hepatocellular tumorigenicity after DHEA treatment was less potent than that after Wy-14,643, but more than that after DEHP treatment. Peroxisomal beta-oxidation activity increased three- or six-fold after a 10 week course of 0.5 or 1% DHEA respectively and this was significantly lower than that induced in Wy-14,643- or DEHP-fed rats. From 52 to 78 weeks these activities increased 3-9 times over that in controls. In both the group of rats treated with Wy-14,643 and those treated with DEHP, peroxisomal beta-oxidation constantly increased 11- to 15-fold during the experiment. Catalase activity increased 1.3- to 1.5-fold for the first 10 weeks of DHEA treatment and then recovered to the control level. The activities of glutathione peroxidase and glutathione S-transferase decreased markedly after 30 weeks in DHEA-treated rats and the decreases were sustained for up to 78 weeks. The profile of changes in enzyme activities in the rats fed DHEA was not significantly different from that of those fed Wy-14,643 or DEHP. There were no increases in 8-hydroxydeoxyguanosine, oxidative DNA damage or lipid peroxide level in the liver in any of the treated rats at 10 or 30 weeks. Since these results showed that the characteristics of hepatocarcinogenesis caused by DHEA were basically similar to those caused by Wy-14,643 and DEHP, typical peroxisome proliferators, hepatocarcinogenesis induced by DHEA is probably due to the same mechanisms as that induced by general peroxisome proliferators.

Elevated plasma soluble interleukin 2 receptor level correlates with defective natural killer and CD8+ T-cells in myelodysplastic syndromes

The plasma soluble interleukin 2 receptor (sIL-2R) level and its relationships with haematologic and immunologic data were examined in 40 patients with myelodysplastic syndromes (MDS). The plasma sIL-2R level was significantly higher in the high-risk MDS group (refractory anaemia with excess blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia) than in the low-risk MDS group (refractory anaemia (RA) and RA with ringed sideroblasts) or in normal subjects, although there was considerable variation in the plasma sIL-2R level within each MDS group. The plasma sIL-2R level correlated positively with the bone marrow cellularity and bone marrow blast mass, but not with the absolute number of CD25+ lymphocytes. This may support the idea that plasma sIL-2R is derived from malignant MDS cells in the bone marrow. The plasma sIL-2R level correlated negatively with the absolute numbers of the CD8+, CD3-CD16+, and CD3-CD56+ cell populations in freshly isolated lymphocytes, the percentage of CD3-CD56+ cells in lymphokine (interleukin 2)-activated killer (LAK) cells, and the cytotoxicity of LAK cells. We conclude that MDS patients having a high plasma sIL-2R level often have a defect in natural killer and CD8+ T-cells.

Processing of contrast polarity of visual images in inferotemporal cortex of the macaque monkey

Cells in the anterior part of the inferotemporal cortex (anterior IT) respond to moderately complex stimulus features of object images. To study dependency of their responses on contrast polarity of stimulus images, we selected cells with optimal stimuli that were defined only by shape and not related to texture or color, and examined effects of reversing the contrast of the image or removing it except for edges between dark and bright parts of the image ("outlining"). The contrast reversal produced a reduction of the response to the optimal stimulus by > 50% in 60% of tested cells; the outlining, in 70%. When the two transformations were considered together, 94% of the cells showed a reduction by > 50%. Effects of the transformations on shape selectivity were also studied by comparing responses to several different shapes each of whose contours were expressed in different ways. Statistically significant changes in relative effectiveness of the different shapes as a function of contour expression were observed in more than half of the cells. These results suggest that responses of individual cells in anterior IT carry information about contrast polarity as well as about shape.

An adult case of polycystic kidney disease associated with congenital hepatic fibrosis

Congenital hepatic fibrosis is often associated with infantile, but not with adult polycystic kidney disease. We report the unusual case of an adult patient with polycystic kidney disease complicated by congenital hepatic fibrosis. A 27-year-old women was admitted to our hospital because of gross hematuria due to hemorrhage from renal cysts. She presented hematemesis from ruptured esophageal varices at the age of 14 years. She was diagnosed as having end-stage renal disease due to polycystic kidney disease at the age of 23 years, and maintenance hemodialysis was initiated the following year. Gross hematuria was managed with supportive therapy. However, the patient developed cholangitis and died of sepsis. Postmortem examinations as well as the patient's clinical course suggested that she had an autosomal dominant type of polycystic kidney disease. Histological findings of the liver were compatible with congenital hepatic fibrosis.

Different modulation of protein kinase C isozymes in dibutyryl cyclic AMP-differentiated PC12h cells

PC12h cells can be differentiated into sympathetic neuron-like cells by various agents, including nerve growth factor, basic fibroblast growth factor, cyclic AMP analogues, and protein kinase C (PKC) activators. To study the involvement of PKC in the process of PC12h cell differentiation by cyclic AMP treatment, PKC isozymes (alpha, beta I, beta II, and gamma) were analyzed using column chromatography and immunoblotting. Two PKC isozymes, PKC(alpha) and PKC(beta II), were predominantly detected in PC12h cells. When stimulated by dibutyryl cyclic AMP, PKC(alpha) levels declined in the cytosolic fraction of the cells, whereas PKC(beta II) levels increased. Increased PKC(beta II) levels were also detected in the particulate fraction, whereas particulate PKC(alpha) levels did not change. The total PKC activity decreased in the cytosolic fraction following cyclic AMP stimulation of PC12h cells, whereas it stayed constant in the particulate fraction. Fractionation on a hydroxyapatite column showed a decreased level of PKC(alpha) activity and a transient increase followed by a decreased level of PKC(beta II) activity. This discrepancy between increased PKC(beta II) immunoreactivity and reduced PKC(beta II) activity suggested the presence of nonactivatable PKC(beta II) in cyclic AMP-treated PC12h extract. These findings indicate that PKC(alpha) and PKC(beta II) are differentially regulated during the differentiation of PC12h cells. In addition, the differentiation of PC12h cells triggered by cyclic AMP seems to involve characteristic alterations of PKC isozymes.

Broad-tuned chromatic inputs to color-selective neurons in the monkey visual cortex

1. Input mechanisms of 21 color-selective cells in cytochrome oxidase-rich blobs in layer II/III of the anesthetized and paralyzed monkey primary visual cortex were studied by an iontophoretic administration of the GABAergic receptor antagonist bicuculline methiodide (BMI). 2. Color-selective blob cells become responsive to originally nonresponsive colors of stimuli or brightness contrast stimuli during removal of intracortical inhibition. 3. The magnitudes of the cells' responses to color stimuli during BMI administration were larger than the expected value of response calculated from the previously reported color tuning of color-selective geniculate cells and emission spectra of color stimulus. 4. These results suggest that color-selective blob cells receive a convergence of different types of chromatic inputs and that intracortical inhibition confers selectivity for a given color on them.

[An adult case of glomerulocystic kidney disease]

A 56-year-old female presented with end-stage renal disease. A CT scan of her kidneys demonstrated that the density of the renal parenchyma was quite low as compared with normal kidneys, and that corticomedullary demarcation was obscured. Magnetic resonance imaging (MRI) disclosed low intensity of the kidneys in T1-weighed images, and high intensity in T2-weighed images. In order to elucidate the etiology of her kidney disease, open renal biopsy was performed. The kidney surface was covered with numerous cysts with a diameter of less than 3 mm. Biopsy specimens from the cortical surface showed multiple cystic lesions. Serial sections of more than 200 slices of the biopsy material demonstrated that traces of collapsed glomeruli were present in most of the cysts. On electron microscopy, some epithelial cells lining the cysts were found to be round-shaped and contained a substantial amount of mitochondria, suggesting proximal tubules. These histological findings were compatible with glomerulocystic kidney disease (GCKD). An adult case of GCKD has rarely been reported, but the CT scan as well as MRI of the kidneys appeared to complement the diagnosis of GCKD. Although the cysts of GCKD have been considered to be dilatations of the Bowman's capsules, our observation suggested that part of the cells lining the cysts consisted of proximal tubular epithelium.

Defective natural killer (NK) cell-mediated cytotoxicity does not imply clonal involvement of NK cells in myelodysplastic syndromes

The clonality of purified cells was examined in 10 myelodysplastic syndromes (MDS) patients by analysing the restriction fragment length polymorphism and methylation pattern of the phosphoglycerate-kinase gene. Natural killer (NK) cell-mediated cytotoxicity was also examined. The granulocytes and monocytes were monoclonal or oligoclonal in all cases, except for the monocytes in one case. Conversely, the NK and T cells had a polyclonal pattern in most cases, including all cases who had defective NK cell-mediated cytotoxicity. The hypothesis that reduced NK cell-mediated cytotoxicity in MDS is caused by a clonal involvement of NK cells was not supported by the present study.

Contractile force and resting tension in the presence of halothane and increased extracellular potassium or decreased extracellular pH in isolated guinea pig atria

To gain a better understanding of the direct actions of halothane on myocardial function in ischaemia, we studied the effects of increasing extracellular potassium concentration and decreasing extracellular pH (acidosis), alone or in combination with halothane, on the contractile force and resting tension in isolated atria. Guinea pig left atria were superfused with Tyrode's solution and stimulated at 1 Hz. Isometric contractile force and resting tension were measured using a force displacement transducer. Perfusate potassium concentrations were increased from 5.4 mmol.L-1 to either 8.1 mmol.L-1 or 10.8 mmol.L-1 by adding KCl to the standard Tyrode's solution, and its pH was decreased from 7.4 to either 7.0 or 6.5 by decreasing bicarbonate. In standard Tyrode's solution (potassium 5.4 mmol.L-1, pH 7.4), halothane 0.5-2% reduced contractile force in a dose-dependent manner (P < 0.05); the effective concentration of halothane for 50% inhibition of contractile force (IC50) was 1.3%. Both increasing extracellular potassium and decreasing extracellular pH decreased the contractile force in a potassium- or pH-dependent fashion. The negative inotropism of halothane (1%) was not altered by increasing potassium concentrations, whereas 1% halothane caused a greater decrease in contractile force at pH 6.5 than at pH 7.4. Halothane (1%) enhanced the acidosis (pH 6.5)-induced increases in resting tension. Arrhythmias were produced in one of eight preparations during acidosis, while four of eight preparations demonstrated arrhythmias during acidosis in the presence of halothane. These data suggest that acidosis and halothane may have a synergistic interaction on the contractile force and resting tension of the atria.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of medetomidine-midazolam on plasma glucose and insulin concentrations in laboratory pigs

Effects of medetomidine (40 micrograms/kg)-midazolam (0.2 mg/kg) on plasma glucose and insulin concentrations were evaluated in laboratory pigs. Intramuscular injection of medetomidine-midazolam induced a gradual hyperglycemic response associated with hypoinsulinemia which was much smaller than that by 80 micrograms/kg of medetomidine alone and was almost within a physiological fluctuation. These mild responses induced by medetomidine-midazolam were antagonized by use of an alpha 2-adrenoreceptor antagonist atipamezole (160 micrograms/kg), therefore those changes were thought to be mainly attributed to the effect of medetomidine on alpha 2-adrenoreceptors. A combination of medetomidine at a low dose and midazolam reduces undesirable effects, while providing more profound sedation than medetomidine alone in laboratory pigs.

Inhibition of NGF-induced neurite outgrowth of PC12 cells by Bacillus cereus sphingomyelinase, a bacterial hemolysin

Sphingomyelinase of Bacillus cereus, a bacterial hemolysin, reduced nerve growth factor (NGF)-induced neurite outgrowth of PC12 cells in a dose-dependent manner. At 200 mU/ml, sphingomyelinase repressed half the neurite outgrowth of the cells at 250 ng/ml NGF. The c-fos superinduction, one of the early responses induced by NGF, was not influenced by this treatment, suggesting that the repression by sphingomyelinase occurred via a protein kinase C-independent pathway.

An autopsy case of light chain deposition disease

This report describes a case of light chain deposition disease (LCDD) with unusual findings of fibrillar structures in the deposits and marked calcification in several organs. A forty-year-old man was initially diagnosed with LCDD in 1987, and died of sepsis three and one-half-years later. Histological examination of autopsy specimens demonstrated eosinophilic amorphous materials, which differed from amyloid, in vessel walls or around parenchymal cells in almost every organ examined. Ultrastructurally, in addition to granular deposits, fibrillar structures were also seen in the deposits. Marked calcification was present in the myocardium, skeletal muscles, adrenal glands and arteries.

Cardiopulmonary effects of medetomidine-midazolam and medetomidine-midazolam- atipamezole in laboratory pigs

The cardiopulmonary effects of medetomidine (40 micrograms/kg)-midazolam (0.2 mg/kg) and medetomidine (40 micrograms/kg)-midazolam (0.2 mg/kg)-atipamezole (160 micrograms/kg) were evaluated in laboratory pigs. The intramuscular administration of medetomidine-midazolam caused a pressor response, characterized by a rapid increase in arterial and pulmonary arterial pressure mediated mainly through systemic and pulmonary vasoconstriction. These pressures decreased after reaching a peak 5 to 10 min after the administration of sedatives, but maintained higher values than the base-line. However, all these changes caused by medetomidine-midazolam were within the physiological fluctuation. In addition, this combination did not induce bradycardia, subsequent hypotension or a significant decrease in cardiac output, which were generally observed with alpha 2-adrenoceptor agonists, and caused fewer changes in the respiratory system. The administration of atipamezole resulted in a marked transient decrease in vascular resistance, and caused a decrease in blood pressure and increases in cardiac output and heart rate. However, these changes were relatively small and sustained for a short time. Thus the combination of medetomidine-midazolam and atipamezole have minimal cardiopulmonary effects and might be used safely in laboratory pigs.

Mutational analysis of the COOH-terminal hydrophobic domain of bovine liver 5'-nucleotidase as a signal for glycosylphosphatidylinositol (GPI) anchor attachment

In order to address the minimum domain of the COOH-terminal hydrophobic region responsible for GPI modification of bovine liver 5'-nucleotidase, we constructed a series of the deletion mutants of the COOH-terminus and expressed them in COS cells. Cells transfected by the deletion mutant of 6 amino acids (-IIILYQ) from the hydrophobic domain (-FSLIFLSVLAVIII-LYQ) did not show any elevation of cell surface-associated 5'-nucleotidase activity, whereas the 2 (-YQ) or 4 (-ILYQ) amino acid deletion mutant retained the bovine liver-derived activity on the cell surface as a GPI-anchored protein. Loss of half the hydrophobic domain (6 or 8 amino acids) resulted in accumulation of the activity in the cell. On the other hand, deletion of the whole hydrophobic domain (17 amino acids) or the entire cleaved-off domain (25 amino acids) made the product secreted into the medium. In conclusion, the hydrophobicity of 13 amino acids in length was enough for the GPI modification of the bovine liver 5'-nucleotidase.

Mycosis fungoides with Leser-Trélat sign: the first report of a patient from Japan

We describe here a 35-year-old Japanese woman with mycosis fungoides (MF) who developed numerous, rapidly-growing, seborrheic keratoses on the front of her neck and chest. To the best of our knowledge, this is the first reported case of MF with Leser-Trélat sign from Japan.

Anemia and neutropenia due to copper deficiency in enteral nutrition

Copper deficiency has been regarded a rare complication of total parenteral nutrition. This report describes the first known case of anemia and neutropenia caused by copper deficiency in a patient receiving long-term enteral nutrition. A 34-year-old man presented with bulbar palsy and tetraplegia after an operation for cerebellar hemorrhage on June 7, 1989. Nasopharyngeal tube feeding with a defined-formula diet (Besvion) was instituted on June 19, 1989. He developed normocytic anemia and neutropenia approximately 19 months after the initiation of the tube feeding. Serum copper and ceruloplasmin levels were markedly below normal. There were anisocytosis and erythrocyte deformities in the peripheral blood smear. Bone marrow aspirates revealed a hypocellular marrow with numerous myeloid and erythroid cells with cytoplasmic vacuoles. Because the amount of copper administered was estimated to be 2.6 to 5.1 mumol/d during the tube feeding, copper deficiency was suspected to be the cause of the hematologic disorders. The patient's daily oral copper intake was increased to 34 mumol/d. His serum copper and ceruloplasmin concentrations reached a normal level after 16 days and 23 days of copper supplementation, respectively. A marked reticulocytosis occurred after 10 days of copper supplementation, and his anemia gradually improved over the next 3 months. His blood neutrophil count also returned to normal within 2 weeks.

Assessment of therapeutic potential of interleukin 2 for myelodysplastic syndromes

The therapeutic potential of interleukin 2 (IL-2) for myelodsplastic syndromes (MDS) was evaluated in vitro. IL-2-induced lymphokine-activated killer (LAK) cells were prepared from 38 MDS patients and 20 normal subjects. The cytotoxicity of LAK cells against K562 and Raji cell lines and MDS blasts was significantly reduced in high-risk MDS (refractory anaemia with excess blasts (RAEB), RAEB in transformation, and leukaemic transformation of MDS), but was relatively well-preserved in low-risk MDS (refractory anaemia (RA) and RA with ringed sideroblasts). Examination of the immunophenotypes of freshly-isolated lymphocytes showed that the percentage of CD4+ cells in low-risk MDS and the percentage of CD3+, CD4+ and CD8+ cell populations in high-risk MDS was significantly reduced compared with these populations in normal subjects. After cultivation with IL-2, these three cell populations were still reduced in the corresponding MDS groups and the percentage of CD3-CD56+ cells were significantly reduced in high-risk MDS. There was a positive correlation between the percentage of K562 cells lysed by MDS LAK cells and the percentage of CD3-CD56+ lymphocytes in MDS LAK cells. These aberrant lymphocyte subpopulations appeared to explain, at least in part, the reduced LAK cell cytotoxicity in MDS. These results present a possibility that IL-2 and LAK therapies are ineffective for most high-risk MDS patients, whereas they have potential value for low-risk MDS patients whose lymphocyte cytotoxicity is usually preserved.

The novel mAb QR6.6 detects a surface molecule on immature thymocytes and inhibits their proliferation on thymic epithelial cells

We previously reported that the nude mouse-derived splenic T cell clone N-9F exhibits a proliferative response when cultured on thymic stromal cells. This N-9F proliferation is mediated by direct cell-to-cell interactions between T and thymic stromal cells. A thymic epithelial cell clone, SL10.3, also supports N-9F growth. To identify the molecule involved in T cell development in the thymus, we established mAb specific to the N-9F clone. One of these mAb, QR6.6, was found to inhibit the N-9F proliferative response on SL10.3. QR6.6-positive cells were detected in thymus but not in other lymphoid organs such as bone marrow, lymph nodes, or spleen. QR6.6-positive cells accounted for 3 to 5% of the cells in adult thymuses whereas higher percentages were found in neonatal (10-20%) and fetal thymuses (70% at E17 and 10-20% at E15). The positive cells were primarily CD4-8- thymocytes in fetuses and CD4-8- to CD4+8+ thymocytes in adults. The QR6.6 mAb precipitates a 100 kDa molecule from the N-9F clone. The addition of the mAb to fetal thymus organ culture reduces the recovery of cells at culture day 4. It was also found that the mAb inhibits fetal thymocyte proliferation on the SL10.3 thymic epithelial cell line. These results suggest that the 100 kDa molecule detected by the QR6.6 mAb may play a crucial role in the early stage of thymocyte development.

The novel mAb QR6.6 detects a surface molecule on immature thymocytes and inhibits their proliferation on thymic epithelial cells

We previously reported that the nude mouse-derived splenic T cell clone N-9F exhibits a proliferative response when cultured on thymic stromal cells. This N-9F proliferation is mediated by direct cell-to-cell interactions between T and thymic stromal cells. A thymic epithelial cell clone, SL10.3, also supports N-9F growth. To identify the molecule involved in T cell development in the thymus, we established mAb specific to the N-9F clone. One of these mAb, QR6.6, was found to inhibit the N-9F proliferative response on SL10.3. QR6.6-positive cells were detected in thymus but not in other lymphoid organs such as bone marrow, lymph nodes, or spleen. QR6.6-positive cells accounted for 3 to 5% of the cells in adult thymuses whereas higher percentages were found in neonatal (10-20%) and fetal thymuses (70% at E17 and 10-20% at E15). The positive cells were primarily CD4-8- thymocytes in fetuses and CD4-8- to CD4+8+ thymocytes in adults. The QR6.6 mAb precipitates a 100 kDa molecule from the N-9F clone. The addition of the mAb to fetal thymus organ culture reduces the recovery of cells at culture day 4. It was also found that the mAb inhibits fetal thymocyte proliferation on the SL10.3 thymic epithelial cell line. These results suggest that the 100 kDa molecule detected by the QR6.6 mAb may play a crucial role in the early stage of thymocyte development.

Congenital biliary dilatation with pancreatico-biliary maljunction: a comparative study between children and adults

A comparative study of congenital biliary dilatation with pancreatico-biliary maljunction in 15 children and 16 adults was undertaken. Cystic and fusiform dilatation of the common bile duct was seen in 9 and 6 cases respectively in the child group, with 8 and 8 cases respectively in the adult group. Cholangiographically, neither the length of the common channel nor the type of pancreatico-ductal union varied significantly between groups. Furthermore the incidence of higher amylase levels of bile showed no apparent variance from group to group. This was also true when looking histologically at the number and distribution of periductal glands surrounding the intra-hepatic bile duct. Therefore, we concluded that there was no essential etiological difference between the two groups.