Basic fibroblast growth factor inhibits choriocapillaris atrophy in rabbit

PURPOSE

To examine the effect of basic fibroblast growth factor on induced choriocapillaris atrophy in vivo.

METHODS

Choriocapillaris atrophy was surgically induced in rabbits by a hydraulic retinal detachment followed by debridement of the retinal pigment epithelium under the detached retina. Three concentrations of basic fibroblast growth factor (0.1 microg/0.1 ml, 1 microg/0.1 ml, or 5 microg/0.1 ml) were injected into the subretinal space and into the vitreous cavity 1, 3, and 5 days after the surgery. For control, only Tris buffer was injected in the same manner. The rabbits were euthanized 7 days after the surgery. Choroidal vascular casts were made and examined by scanning electron microscopy. The choriocapillaris atrophy was quantified by computer-assisted image analysis of photographs of the choriocapillaries. The area of the choriocapillaris and number of intercapillary spaces in the choriocapillaris that corresponded to the density of the capillary network were measured.

RESULTS

The average area of the choriocapillaris in the eyes treated with 1 microg/0.1 ml of basic fibroblast growth factor was significantly larger at 75.1 +/- 3.0% than that in the control eyes at 67.2 +/- 5.6% (P =.021). The average area of the choriocapillaris in the 0.1 microg/0.1 ml of basic fibroblast growth factor group was not statistically different from the control. The number of intercapillary spaces of the choriocapillaris was 132 +/- 12 in the 0.1 microg/0.1 ml of basic fibroblast growth factor group, 124 +/- 46 in the 1 microg/0.1 ml of basic fibroblast growth factor group, and 75 +/- 14 in the control group. The higher number of spaces in the treated group was statistically significant (P =.026).

CONCLUSIONS

Basic fibroblast growth factor decreased the atrophy of the choriocapillaris after removal of the retinal pigment epithelium in rabbit eyes. These results suggest that basic fibroblast growth factor may play a role in the survival of the choriocapillaris in vivo.

[Detection of O,O,S-trimethyl phosphorodithioate, an impurity in phenthoate (PAP), in komatsuna]

An unknown peak (peak A) was detected in a mass chromatogram of komatsuna extract containing a high concentration of phenthoate (PAP), and it was considered to be O,O,S-trimethyl phosphorodithioate (OOS). Although it is generally known that OOS exists as an impurity in technical malathion and PAP, it has not been reported that OOS is present in crops. Since an OOS standard is not commercially available, OOS was separated and purified from commercial emulsifiable malathion. Peak A was confirmed to be OOS by GC/MS using the purified OOS. The concentration of OOS was estimated to be 0.02 microgram/g. It is supposed that OOS was detected in crops because they contained a high concentration of PAP residue.

Myristoleic acid, a cytotoxic component in the extract from Serenoa repens, induces apoptosis and necrosis in human prostatic LNCaP cells

BACKGROUND

Prostatic tumors are well known to progress to hormonal therapy-resistant terminal states. At this stage, there are no chemotherapeutic agents to affect clinical outcome. An effective cell death inducer for these prostate cells may be a candidate as an attractive antitumor agent. The extracts from S. repens have been used to improve the state of prostatic diseases and we have attempted to identify the effective component from the extract.

METHODS

Cell viability was examined in LNCaP cells, an in vitro model for hormonal therapy-resistant prostatic tumor.

RESULTS

We found that exposure of the extract from S. repens resulted in cell death of LNCaP cells. We also identified myristoleic acid as one of the cytotoxic components in the extract. The cell death exhibited both apoptotic and necrotic nuclear morphology as determined by Hoechst 33342 staining. Cell death was also partially associated with caspase activation.

CONCLUSIONS

It was demonstrated that the extract from S. repens and myristoleic acid induces mixed cell death of apoptosis and necrosis in LNCaP cells. These results suggest that the extract and myristoleic acid may develop attractive new tools for the treatment of prostate cancer.

Aminopeptidase N regulated by zinc in human prostate participates in tumor cell invasion

Aminopeptidase N (AP-N) degrades collagen type IV and is proposed to play a role in tumor invasion. However, the precise functions of AP-N in tumor cells and the relationship of AP-N to prostate cancer remains unclear. In our study, we examined a possible role for zinc in the regulation of AP-N enzymatic activity in relation to tumor cell invasion in human prostate. AP-N purified from human prostate was irreversibly inhibited by low concentrations of zinc (Ki = 11.2 microM) and bestatin. AP-N, which has zinc in the active center, was also inhibited by the chelating agents, EDTA, o-phenanthroline and EGTA. EDTA was shown to remove zinc from the enzyme. When the effects of zinc and bestatin on invasion of PC-3 cells were investigated in vitro using a Transwell cell-culture chamber, zinc and bestatin effectively suppressed cell invasion into Matrigel at the concentration range of 50-100 microM. These results strongly suggest that the suppression of PC-3 cell invasion by zinc is based on the inhibition of AP-N activity by zinc. We also evaluated the expression of AP-N to investigate the relationship with the progression of prostate disease in human cancerous prostate. AP-N was found to be located at the cytoplasmic membranes of prostate gland epithelial cells and to be expressed more in prostate cancer, while the expression of prostate-specific antigen (PSA), which is a useful marker for prostate cancer, was shown in normal and cancer tissues, suggesting that AP-N is potentially a good histological marker of prostate cancer. Thus, highly expressed AP-N in human cancerous prostate probably plays an important role in the invasion and metastasis of prostate cancer cells.

Inhibition of aminopeptidase N (AP-N) and urokinase-type plasminogen activator (uPA) by zinc suppresses the invasion activity in human urological cancer cells

Zinc is an essential heavy metal and is more abundant in human prostate and kidney than in other tissues. The effects of zinc on the invasion activity of human prostate and renal cancer cell lines, PC-3, LNCaP and SKRC-1, were investigated in vitro using a Transwell cell-culture chamber and were compared with specific protease inhibitors for MMPs, uPA and AP-N, respectively. The invasion activity of PC-3 cells was effectively suppressed by zinc and by all protease inhibitors in a dose-dependent manner. The invasion activity of LNCaP cells was almost unaffected by these inhibitors. In SKRC-1 cells, the invasion activity was strongly suppressed by MP03, although a moderate inhibition by zinc and bestatin was observed. The purified AP-N activity was strongly inhibited by zinc at a concentration similar to that suppressing the invasion activity of PC-3 cells and this inhibition by zinc was apparently competitive. Although the purified uPA activity was also inhibited by zinc, this inhibition was uncompetitive. AP-N was expressed abundantly on the membrane fraction of PC-3 cells among these cells tested, while its expression on the membrane fraction of SKRC-1 cells was weaker than that of PC-3 cells. The expression of uPA was also highest on the membrane fraction of PC-3 cells. These results suggest that AP-N and uPA may be involved in the invasion of human prostate cancer cells and that zinc probably participates in the invasion and metastasis of cancer cells through the regulation of the enzymatic activity of AP-N and uPA in human cancerous prostate.

Effect of probucol in lecithin-cholesterol acyltransferase-deficient mice: inhibition of 2 independent cellular cholesterol-releasing pathways in vivo

Cellular cholesterol release takes place by at least 2 distinct mechanisms: the lecithin-cholesterol acyltransferase (LCAT)-driven net efflux by cholesterol diffusion and the generation of high density lipoprotein (HDL) with cellular cholesterol and phospholipid on the cell-apolipoprotein interaction. Therefore, LCAT deficiency impairs the former pathway, and the latter can be inhibited by probucol, which interferes with the apolipoprotein-cell interaction. Hence, probucol was given to the LCAT-deficient mice in the attempt to suppress both of these pathways. The mice were fed low (0.2%) and high (1.2%) cholesterol diets containing 0.5% probucol for 2 weeks. LCAT deficiency and probucol markedly decreased plasma HDL, and the effects were synergistic. Tissue cholesterol content was lower in the adrenal glands and ovaries in the LCAT-deficient mice and in the probucol-treated mice, suggesting that HDL is a main cholesterol provider for these organs. It was also moderately decreased in the spleen of the low cholesterol-fed female mice and in the thyroid gland of the low cholesterol-fed male mice. On the other hand, the esterified cholesterol content in the liver was substantially increased by the probucol treatment with a high cholesterol diet in the LCAT-deficient mice but not in the wild-type mice. Among the groups, there was no significant difference in the tissue cholesterol levels in other organs, such as the liver, spleen, thymus, brain, erythrocytes, thyroid gland, testis, and aorta, resulting from either LCAT deficiency or probucol. Thus, the apolipoprotein-mediated mechanism plays a significant role in the export of cellular cholesterol in the liver, indicating that the liver is a major site of the HDL assembly. Otherwise, tissue cholesterol homeostasis can largely be maintained in mice even when the assembly of new HDL is inhibited by probucol in the absence of LCAT. Nonspecific diffusion of cholesterol perhaps adequately maintains the homeostasis in the experimental condition.

Extract from Serenoa repens suppresses the invasion activity of human urological cancer cells by inhibiting urokinase-type plasminogen activator

We used three human urological cancer cell lines, PC-3, LNCaP and SKRC-1, to investigate the effects of the extract from Serenoa repens (Palmae) on tumor cell invasion. The invasion activity of these cell lines was determined in vitro using a Transwell cell-culture chamber. The invasion activity of PC-3 cells into Matrigel was effectively suppressed by the extract at the concentration range of 1-10 microg/ml, while that of LNCaP and SKRC-1 cells was unaffected by the extract. The extract did not affect the viability, adhesion ability, or motility of the cell lines. uPA is more strongly expressed on the membrane fraction of PC-3 cells than that of LNCaP or SKRC-1 cells. The purified uPA activity is inhibited by the extract from S. repens in a dose-dependent manner, suggesting that the suppression of PC-3 cell invasion by the extract is based on an inhibition of the uPA activity which is necessary for tumor cell invasion. These data suggest that the extract from S. repens specifically inhibits the uPA activity and may therefore be useful for the therapeutic treatment of prostate cancer.

Induction of epithelial differentiation and DNA demethylation in hamster malignant oral keratinocyte by ornithine decarboxylase antizyme

The hamster ornithine decarboxylase antizyme (ODC-Az) cDNA was transfected into the hamster malignant oral keratinocyte cell line, HCPC-1. Ectopic expression of ODC-Az resulted in the reversion of malignant phenotypes and alteration of DNA methylation status of CCGG sites. The phenotypes examined include ODC enzymatic activity, doubling time, morphological change, anchorage dependent growth, tumorigenicity in nude mice, induction of epithelial differentiation marker protein (involucrin), and change of cell cycle position. Comparison of CCGG DNA methylation status of the ODC-Az and control vector transfectants revealed a significant increase in demethylation of 5-methyl cytosines (m5C) of CCGG sites in the ODC-Az transfectants. Ectopic expression of ODC-Az gene in hamster malignant oral keratinocytes led to reduce ODC activity and the subsequent demethylation of 5-methyl cytosines, presumably via the ODC/ polyamines/ decarboxylated S-adenosylmethionine (dc-AdoMet) pathways. Our data suggest that ODC-Az shared the same pathway of polyamines/ dc-AdoMet/DNA methyltransferase (DNA MTase). We propose that ODC-Az mediates a novel mechanism in tumor suppression by DNA demethylation and presumably re-activation of key cellular genes silenced by DNA hypermethylation during cancer development. Oncogene (2001) 20, 24 - 33.

Retinal changes after retinal translocation surgery with scleral imbrication in dog eyes

PURPOSE

To examine retinal changes induced by scleral imbrication during retinal translocation surgery in dog eyes.

METHODS

Fifteen dogs were anesthetized and underwent retinal translocation surgery. After lensectomy and vitrectomy, an intentional retinal detachment was created, and the upper temporal sclera around the equator was imbricated with five mattress sutures. Translocated distances were calculated by pre- and postoperative photographs. At 1, 2, and 4 weeks after the surgery, the retina was studied by TdT-dNTP terminal nick-end labeling (TUNEL) and immunohistochemistry of peanut agglutinin (PNA) lectin and glial fibrillary acidic protein (GFAP).

RESULTS

The retina was translocated by a mean distance of 0.53 +/- 0.30 disc diameters or 959 +/- 543 micrometer. Retinal folds were created around the optic disc in all eyes. Histologic examination of the retinal folds 1 week after the surgery showed many TUNEL-positive cells in the outer nuclear layer, loss of photoreceptor cells, and shortening of the outer and inner segments. A strong immunoreactivity to GFAP was detected in the folds of the retina.

CONCLUSIONS

. The results demonstrated that retinal translocation surgery by scleral imbrication inevitably caused retinal folds as a postoperative complication, and the retina within the folds showed extensive loss of photoreceptor cells. It is recommended that the foveal translocation surgery be planned to avoid involving the fovea in the retinal folds.

Structural features of an anti-diabetic polysaccharide (TAP) from Tremella aurantia

The structure of an anti-diabetic polysaccharide (TAP) obtained from the fruiting bodies of Tremella aurantia was investigated by methylation analysis, Smith degradation, partial acid hydrolysis, 13C-NMR spectrometry, and enzymatic digestion. The results suggested that TAP was composed of (1-->3)-linked alpha-D-mannopyranosyl residues as a backbone, some of which were substituted at position 2 with (1-->3)-linked beta-D-xylopyranose side chains and with beta-D-glucopyransyluronic acid at position 4 linked to terminal alpha-D-mannopyranose.

Virus-mediated transduction of apolipoprotein E (ApoE)-sendai develops lipoprotein glomerulopathy in ApoE-deficient mice

Lipoprotein glomerulopathy (LPG) is a unique renal disease characterized by thrombus-like substances in markedly dilated glomerular capillaries, dysbetalipoproteinemia, and elevated plasma concentrations of apoE. Recent studies identified several apoE mutations in patients with LPG, including apoE2(R145P) Sendai (apoE-Sendai). Virus-mediated transduction of apoE-Sendai in apoE-deficient hypercholesterolemic mice resulted in insufficient correction of hypercholesterolemia and a marked and temporal induction of plasma triglyceride levels. In vitro binding studies showed that apoE-Sendai has a reduced affinity for the low density lipoprotein receptor, suggesting that dysbetalipoproteinemia in LPG is caused by the apoE mutation. Furthermore, histological examination revealed marked intraglomerular depositions of apoE-containing lipoproteins in mice injected with apoE-Sendai virus. These LPG-like depositions were detected 6 days after virus injection and were sustained for at least 60 days. Our results demonstrated that apoE-Sendai is an etiological cause of LPG.

[Photodynamic diagnosis and photodynamic therapy for experimental hepatoma with ME 2906]

We studied the effects of photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in confirming the existence of hepatoma, using the new photosensitizer mono-L-aspartyl chlorine 6. Japanese white rabbits were selected for abdominal incision under intravenous anesthesia, and VX 2 tumor cells were transplanted into the left liver lobe to create a hepatoma model. In the experiment, hepatoma of 1 cm in diameter (at one week after transplantation) was radiated with a semiconducter laser (664 nm, 200 J/cm2) for treatment.

Gradual changes in environmental light intensity and entrainment of circadian rhythms

Environmental light-dark alternation is the most potent zeitgeber of circadian rhythm in most organisms. Responses of the circadian system to brief light pulses and rectangular light-dark cycles have been extensively studied in many species. Under natural conditions, however, light intensity changes gradually throughout the day, and light-responsive neurons in the mammalian circadian system have response characteristics suitable for detection of gradual changes in light intensity during twilight. Several researchers have examined rhythm-entraining properties of artificial twilight and fluctuating light intensity cycles, and have stressed the importance of gradual transition between light and darkness for entrainment of circadian rhythms. But many questions about photic entrainment still remain to be answered. Further studies on entrainment of circadian rhythms will be useful for prevention and treatment of circadian rhythm-related disorders.

Ionic current model of rabbit retinal horizontal cell

We propose a mathematical model of rabbit retinal horizontal cell based on the ionic current mechanisms. Five types of ionic currents in rabbit retinal horizontal cell, I(Na), I(Ca), I(Kv), I(A) and I(Ka), are described by Hodgkin-Huxley type equations based on voltage clamp measurements. In simulation the model reproduced similar responses to voltage and current clamp experiments. Under the current clamp experiment a repetitive action potential was found on A-type rabbit horizontal cells. Our result suggests that the repetitive action potential is generated by an interaction Of I(Ca) and I(Kv).

Relation between RLP-triglyceride to RLP-cholesterol ratio and particle size distribution in RLP-cholesterol profiles by HPLC

Remnant-Like Particles (RLP) isolated by an immunoseparation method are heterogeneous in their physical and biochemical properties. The objective of this study was to examine the relation between RLP-triglyceride (RLP-TG) to RLP-cholesterol (RLP-C) ratio and particle size distribution in RLP-C profiles from patients with hyperlipoproteinemia by HPLC. RLP were isolated from serum samples from 147 subjects. RLP-C and RLP-TG were quantified by respective enzymatic methods. Particle sizes of the RLP were measured using HPLC with 4 connected TSKgel LipopropakXL columns. Based on HPLC profiles of RLP-C from individual subjects, three different types were classified: predominantly LDL, predominantly VLDL, and mostly VLDL types. All patients with type III hyperlipidemia were mostly VLDL type but with smaller particle size of VLDL (32 nm) than other subjects. Severe hypertriglyceridemic (TG>4.52 mmoll(-1)) subjects were mostly VLDL type with large particle size (41 nm). As for all subjects (n=105) without predominantly LDL type, a significant correlation between RLP particle size and RLP-TG to RLP-C ratio (r=0. 432, P<0.001) was obtained, but not in case of serum TG to RLP-C ratio (r=0.062). It suggests that RLP-TG to RLP-C ratio might be used for discrimination of atherogenic smaller-sized lipoprotein from larger-sized TG-rich lipoprotein remnants.

Range of entrainment of rat circadian rhythms to sinusoidal light-intensity cycles

The range of entrainment of the circadian behavioral rhythm was compared between two groups of Sprague-Dawley rats (each n = 10) exposed to daily cycles of rectangular light-dark alternation (LD) and sinusoidal fluctuations of light intensity (SINE), respectively. The maximum illuminance (20 lx), the minimum illuminance (0.01 lx), and the total amount of light exposure per cycle were the same under the two lighting conditions. The periods (Ts) of both lighting cycles were lengthened stepwise from 24 through 25, 26, 26.5, 27, 27. 5, and 28 h to 28.5 h in experiment 1 and were shortened stepwise from 24 through 23.5, 23, and 22.5 h to 22 h in experiment 2. Each T cycle lasted for 30 cycles. In experiment 1, 60% of rats under the LD condition entrained up to T = 28.5 h, whereas 50% of rats under the SINE condition entrained up to T = 28.5 h. In experiment 2, no animal under the LD condition entrained to T < 23.5 h, whereas 40% of rats under the SINE condition entrained down to T = 23 h and 20% of rats remained to entrain down to T = 22 h cycles. The phase angle of entrainment was systematically changed, depending on T under both conditions. These results suggest that the lower limit of entrainment is expanded under the SINE condition compared with the LD condition.

Selection of mobile phase in high-performance liquid chromatographic determination for medicines

A convenient method was developed to select mobile phase to separate drugs commonly used in clinical therapy, using high-performance liquid chromatography (HPLC). The separation conditions determined by this method were similar for each compound. Two kinds of mobile phase, a mixture of acetonitrile-phosphate buffers, pH 4.2 and 2.5, was used and the composition of mobile phase used for a drug in HPLC analysis was systematically determined as follows: (1) the retention time of a drug was measured under the gradient condition, (2) this retention time value was applied to the regression equation which was determined from the retention time values of p-hydroxybenzoate derivatives under the gradient condition and the concentration of acetonitrile in mobile phase, giving about 5 min of retention time, (3) percentage of acetonitrile in the isocratic condition was calculated from this regression equation and a target drug was eluted with the mobile phase consisting of the calculated concentration of acetonitrile. According to the proposed method, the composition of mobile phase, with which retention time value was between 4 to 8 min in the isocratic condition, was examined for 75 drugs clinically used. Seventy-two of the 75 drugs were analyzed well in the mobile phase, their composition was calculated by the regression equation, and the peak shape of each compound was observed to be sharp. Using this method, the time required for not only the setting of HPLC conditions but also the analysis will be shortened.

Secretory cell differentiation and mucus secretion in cultures of human nasal epithelial cells: use of a monoclonal antibody to study human nasal mucin

We have developed an air-liquid interface culture system for human nasal epithelial cells that differentiate into mucociliary phenotypes in a defined serum-free medium. Dissociated cells obtained from nasal polyps were cultured on a collagen gel substrate. At confluence, the cells lost characteristics of differentiated cells, and secretory cell and ciliated cell differentiation appeared after 7 days in an air-liquid interface. After 21 days, about half of the epithelial cells were stained with Alcian blue-periodic acid-Schiff stain or monoclonal antibody HCS18, which was directed against human nasal mucin specific for epithelial secretory (goblet) cells. The quantitative examination using the antibody HCS18 revealed that the antibody-reactive nasal mucin was secreted only on the apical side of the cultures, and interleukin-1beta and tumor necrosis factor alpha stimulated these mucus secretions. The culture system with an antimucin monoclonal antibody developed in this study should be useful for studying polarized mucus secretion from human nasal epithelial cells.

Effect of a polysaccharide (TAP) from the fruiting bodies of Tremella aurantia on glucose metabolism in mouse liver

An acidic polysaccharide (TAP) obtained from the fruiting bodies of Tremella aurantia significantly increased the activities of glucokinase, hexokinase, and glucose-6-phosphate dehydrogenase, and decreased the activity of glucose-6-phosphatase in normal and diabetic mouse liver after intraperitoneal administration, while the glycogen content in the liver was reduced. Furthermore, TAP lowered the plasma cholesterol level in normal and diabetic mice.

Assessment of between-instrument variations in a HPLC method for serum lipoproteins and its traceability to reference methods for total cholesterol and HDL-cholesterol

BACKGROUND

The main purpose of this study was to evaluate the between-instrument variation of the HPLC method for the measurement of total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), VLDL-cholesterol (VLDL-C), chylomicron cholesterol (CM-C), LDL size, and HDL size. Furthermore, the accuracy of the HPLC was assessed for the determination of TC and HDL-C, compared with CDC reference methods.

METHODS

We used four HPLC instruments with different column-load numbers from 250 to 5000. For accuracy assessment of TC and HDL-C, we used the reference methods recommended by the CDC.

RESULTS

The values measured by the four instruments were highly correlated with each other (mean r = 0.965), and the absolute mean differences were 4-43 mg/L for TC, 4-30 mg/L for HDL-C, 0-48 mg/L for LDL-C, 7-66 mg/L for VLDL-C, 0-7 mg/L for CM-C, 0.1-0.3 nm for LDL size, and 0-0.1 nm for HDL size. For TC, the HPLC instruments showed high correlation and good agreement with the reference method: r = 0.997; total error <6.6%; absolute mean bias <1.2%. For HDL-C, the results from the HPLC method were significantly higher (10.8% absolute mean bias) than those of the CDC reference method, in spite of good correlation between the two methods (r = 0.998).

CONCLUSIONS

The between-instrument variation in serum lipoprotein analysis by HPLC was confirmed to be very small. This method met the US National Cholesterol Education Program's performance criteria for TC but not for HDL-C.

[Treatment policy for colon cancer liver metastases]

Hepatectomy provides the highest rates of cure among the methods for treating colon cancer liver metastases, but it cannot be performed in many cases. Hepatectomy is the treatment of choice for colon cancer liver metastases in our department, but we conduct transcatheter arterial embolization alone or in combination with MCT on patients in whom hepatectomy cannot be performed or those with residual tumor following hepatectomy. Transcatheter arterial embolization is conducted on patients shown to have tumor vessels, following a single intra-arterial shot of an anticancer drug. MCT is performed under general anesthetic percutaneously or by abdominal section in patients who have not responded well to transcatheter arterial embolization, in order to improve the effectiveness of treatment on the tumor overall. We consider the combination of transcatheter arterial embolization and MCT to be an effective treatment for patients with a colon cancer liver metastasis who present with tumor vessels.

Structural features and hypoglycemic activity of a polysaccharide (CS-F10) from the cultured mycelium of Cordyceps sinensis

A polysaccharide (CS-F10) purified from a hot water extract of the cultured mycelium of Cordyceps sinensis was composed of galactose, glucose and mannose in a molar ratio of 43:33:24; its molecular weight was estimated to be about 15000. The results of chemical and spectroscopic investigations suggest that CS-F10 has a comb-type structure, and has alpha-D-glucopyranosyl residues on the terminal of the side-chains and characteristic sugar residues of C. sinensis i.e., 1,5-linked beta-D-galactofuranosyl residues. CS-F10 significantly lowered the plasma glucose level in normal, streptozotocin (STZ)-induced diabetic and epinephrine-induced hyperglycemic mice after intraperitoneal administration (50 mg/kg). Administration of CS-F10 to STZ-induced diabetic mice significantly increased the activity of hepatic glucokinase. A significant reduction in the hepatic glucose output was observed following the infusion of CS-F10 using the perfused rat liver. CS-F10 also significantly decreased protein content of facilitative glucose transporter isoform 2 (GLUT2) from rat liver following i.p. administration. These effects presumably contribute to the hypoglycemic activity.

Activation of macrophages and neutrophils by an endothelium growth suppressing factor

An endothelial cell growth-suppressing factor (EGSF) was purified from the serum-free conditioned medium of the mouse P388D1 culture in the presence of carboxymethylated curdlan. The purified EGSF showed two bands corresponding to the molecular masses of 55 and 63 kDa by silver staining on a SDS-polyacrylamide gel under reducing conditions. This factor strongly suppressed the proliferation of endothelial cells from bovine artery, human umbilical vein, and human dermal vas capillare and this suppression was observed to be reversible. We found that EGSF was a potent chemoattractant for macrophages and neutrophils. EGSF mediated the adhesion of neutrophils to BAEs and transendothelial migration of neutrophils. Macrophages stimulated by EGSF produced nitrite in a dose-dependent manner. EGSF did not affect the proliferation of T lymphocytes. These findings suggest that EGSF acts not only as a potent inhibitor for the growth of endothelial cells but also an activator for macrophages and neutrophils. Thus EGSF plays a role in an inflammatory response in the endothelium.

[An analysis of the cardiovascular responses under hyper- and hypo-gravity environments using a mathematical model]

Gravity affects cardiovascular control system remarkably. Internal control mechanism responsible for such cardiovascular changes under hypo- and hyper-gravity have not yet been fully understood, although many biological and physiological measurements as to cardiovascular system have been conducted since man's first exploration to space. One reason for this arises from the difficulty in continuous and simultaneous measurements of hemodynamics of many parts of the body. To overcome this difficulty, a mathematical model was constructed based on animal and human physiological evidence in our previous study. In the present study, the model is used for explaining hemodynamics during hyper- and hypo-gravity environments obtained during parabolic flight. The parabolic flight experiment was conducted by a small rear-jet MU300. Three university male students volunteered as subjects. Five to eleven parabolic flights per day were performed for 6 days. The subjects sat on a chair either in an upright position or a 45 degree reclining position. Electrocardiogram and finger blood pressure were measured continuously during the flights. Variable parameters of the model were adjusted so that heart rate and blood pressure of the model fit to those of the experiment. It was shown that the model can quantitatively reproduce and predict experimental heart rate and blood pressure during a parabolic flight. Analysis of internal property of the model revealed hemodynamics of the human cardiovascular system during a parabolic flight which explains the mechanisms of cardiovascular responses under hyper- and hypo-gravitational environments.

Growth suppressing factor for endothelial cells exhibits tumor regressing activity

Endothelium growth suppressing and tumor-regressing activities were copurified from the conditioned medium of P388D1 culture in the presence of 100 microg/ml carboxymethylated curdlan by a procedure including ammonium sulfate fractionation and six column chromatographies of Ceramic hydroxyapatite, Q-Sepharose, Sephacryl S-300 HR, Matrex PBA-30, PBE94, and anti-bovine serum albumin (anti-BSA) agarose. The intravenous administration of the purified growth suppressing factor for endothelial cells to sarcoma 180-bearing mouse caused a rapid decrease in the number of viable tumor cells in tumor lumps within 16 h. Immunohistochemical study showed that the intravenous injection of the purified factor to sarcoma 180-bearing mouse resulted in hemorrhagic disorder all over the tissue in the tumor lamp. Thus, the purified factor exhibited not only growth suppressing activity for endothelial cells but also tumor regressing activity at a concentration as low as about 15 ng/mouse. The purified factor significantly inhibited in vitro tubulogenesis of bovine artery, human umbilical vein, and adult human darmal microvascular endothelial cells on collagen gel at a concentration of about 5 ng/ml. After the tube formation of endothelial cells was completed on a collagen gel, the purified factor disrupted the tubes at a concentration of about 5 ng/ml within 48 h. These findings demonstrate that endothelium growth suppressing factor is a potent inhibitor of angiogenesis as well as the growth of endothelial cells, and may bring about the regression of a solid tumor by inhibiting angiogenesis.

The lower entrainable limit of rat circadian rhythm to sinusoidal light intensity cycles: a preliminary study

The lower entrainable limit of the circadian behavioral rhythm was examined in rats exposed to sinusoidal light intensity cycles with maximum illuminance of 20 lux and the minimum of 0.01 lux. The period (T) of the light intensity cycle was initially kept at 23.5 h for 20 cycles, and then shortened to 23 h for 33 cycles. Thereafter the rats were released into constant darkness. Five out of 10 rats entrained their circadian rhythms to T = 23.5-h cycle, and they also entrained to the T = 23-h cycle. The phase angle of entrainment was almost unchanged when T was shortened from 23.5 h to 23 h. These results suggest that the T = 23-h cycle was close to the lower limit of entrainment.

Purification of a growth-suppressing factor for bovine artery endothelial cells from mouse lymphoma P388D1 cells

A growth-suppressing factor for bovine artery endothelial cells (BAEGSF) was purified from the conditioned medium of a mouse lymphoma P388D1 cell culture in the presence of 100 microg/ml carboxymethylated curdlan. The purification steps included, in order, ammonium sulfate fractionation and eight stages of column chromatography on Macro-Prep Ceramic Hydroxyapatite, Q-Sepharose, Sephacryl S-300 HR, Matrex PBA-30, CHT II, Resource-Q, anti-bovine serum albumin (BSA) agarose, and Superdex 200HR columns. The purified BAEGSF showed two bands with silver staining on a sodium dodecyl sulfate polyacrylamide gel under reducing conditions (SDS-PAGE) and their molecular weights were estimated as approximately 55 and 63 kDa, while the molecular weight of the purified BAEGSF was estimated as about 65 kDa by gel filtration using Superdex 200HR. This result shows that BAEGSF obtained from Superdex 200HR chromatography is a partially purified preparation and suggests that one of the two bands on SDS-PAGE corresponds to BAEGSF. BAEGSF was shown not to have a lethal effect on endothelial cells, but had an inhibitory action on the proliferation of these cells. Furthermore, the growth-suppressing activity of BAEGSF for bovine artery endothelial cells (BAE) was not inhibited by anti-transforming growth factor-beta (TGF-beta), anti-tumor necrosis factor-alpha (TNF-alpha), and anti-interleukin-1 (IL-1) antibodies. These results suggest that BAEGSF is different from TGF-beta, TNF-alpha, and IL-1 which have been reported to inhibit BAE growth.

[A basic study of photodynamic therapy of experimental hepatoma with ME 2906]

We have studied effects of photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in hepatoma as confirmed by the existence of hepatoma when using a new photosensitizer mono-L-aspartyl chlorin e6. Japanese white rabbits were selected to perform abdominal incision under intravenous anesthesia and transplant VX2 tumor cells into the liver left lobe for the hepatoma model. Hepatoma of 1 cm in diameter (at one week after transplantation) was used experimentally to radiate a semiconductor laser (664 nm, 200 J/cm2) for treatment.

Quantitative detection method of triglycerides in serum lipoproteins and serum-free glycerol by high-performance liquid chromatography

We have developed a simple and reliable method for quantitative detection of triglycerides (TG) in serum lipoproteins and serum-free glycerol (FG) by high-performance liquid chromatography (HPLC). After separation of serum constituents using a new gel-permeation column (TSK gel Lipopropak XL, Tosoh) and a new eluent (TSK eluent LP-2, Tosoh), TG and FG were detected by on-line reaction using a modified reagent which contained glycerol kinase, glycerol-3-phosphate oxidase and lipoprotein lipase. HPLC patterns showed five peaks corresponding to chylomicrons, very-low-density, low-density, high-density lipoproteins and FG. Absolute concentrations of TG in each lipoprotein fraction and serum FG were calculated from the corresponding peak areas using standard FG as a calibrator. Due to its very high sensitivity of peak detection, this method has become desirable for the analyses of lipoproteins of very low concentrations such as in cell culture systems. This technique will contribute to a better understanding of lipoprotein TG and serum FG distribution in human and nonhuman subjects.

Biological activities of (1-->3)-beta-D-glucans with reducing glucose side chains

Newly synthesized (1-->3)-beta-D-glucans with reducing glucose side chains (6-O-glucopyranosylated curdlan and 3-O-glucopyranosylated curdlan, with glucose linked directly (except for anomeric carbon) had antitumor activity against mice sarcoma 180 in mice. The two glucans potentiated the reticuloendotheliai system and activated macrophages (increased their glucose consumption). The activity inducing tumor regressing factor of the glucan derivatives was stronger than a linear (1-->3)-beta-D-glucan (curdlan).

[Progress of enteral nutrition]

Intravenous hyperalimentation and enteral nutrition are the main surgical nutrition methods. IVH play an active role in therapeutic nutrition, although made rapid progress has been made in enteral nutrition, resulting in its wide clinical application. Branched-chain amino acids are useful in improving the nitrogen balance in patients who have undergone major surgical procedures or significant stress. Furthermore, their superiority over a mixed oral protein diet in patients with hepatic encephalopathy has been confirmed clinically. Medium-chain triglycerides (MCT) are an important energy source. Their advantages include easy absorbtion by the intestinal mucosa, lack of stimulation of insulin excretion, and suppression of the reticuloendothelial system. However, the ratio of long-chain triglyceride (LCT) to MCT should be evaluated in many cases. EPA can prevent various adult diseases. Many nutrients contain EPA and it is clinically used both enterally and parenterally. Glutamine is effective in the repair of small intestinal mucosal damage, since it suppresses bacterial translocation, effects of growth hormone, epidermal growth factor (EGF), and nucleic acid on nutritional status are being evaluated clinically. Home enteral nutrition (HEN) has become more common in the past five years although close, cooperation between medical staff and the family is necessary its success.

Blood-nerve barrier in IgM paraproteinemic neuropathy: a clinicopathologic assessment

We report the pathologic findings in a patient with sensorimotor neuropathy associated with Waldenström's macroglobulinemia, particularly in relation to blood-nerve barrier defects. The monoclonal IgM was of kappa type and possessed anti-HNK-1 activity. A sural nerve biopsy specimen revealed severe loss of myelinated and unmyelinated nerve fibers and gaps between adjacent endothelial cells of small endoneurial vessels. Postmortem findings 3 years later included severe loss of myelinated nerve fibers and diffuse infiltration by lymphoplasmacytic B cells throughout the peripheral nervous system, sparing the central nervous system. Findings in this case suggest an immune attack against endoneurial endothelial cells with permeation of IgM into peripheral nerve tissue.

Growth suppressing activity for endothelial cells induced from macrophages by carboxymethylated curdlan

A carboxymethylated derivative of a linear (1-->3)-beta-D-glucan (CMCD) from Alcaligenes faecalis var. myxogenes acted directly on mouse peritoneal macrophages and mouse lymphoma P388D1 cells, and induced a growth suppressing activity for bovine artery endothelial cells (BAEs) from themselves at a concentration of 100 micrograms/ml. The suppressing activity was also detected in the mouse serum administered as an i.p. injection of CMCD at a dose of 100 mg/kg, suggesting that the growth suppressing activity was induced from macrophages potentiated by CMCD in vivo.

Desensitization of the GABAA receptor shifts the dynamic range of retinal horizontal cells due to light and dark adaptation

The effects of the GABAergic pathway on the dynamic range of the light response of cone-driven horizontal cells (HCs) in the carp retina were investigated using conventional intracellular recordings and computer simulations. The amplitude of the HC responses to repetitive test flashes was altered by background illumination in control Ringer's solution, but was not changed following the application of picrotoxin or bicuculline, which suggests that GABAA receptors mediate the subsequent change in light response. This phenomenon was simulated by introducing the desensitization mechanism of the GABAA receptor into a cone-HC network model. These results suggest that desensitization of the GABAA receptor shifts the dynamic range of the HCs due to light and dark adaptation.

Preparation of novel (1-->3)-beta-D-glucans having reducing glucose side chains

Novel (1-->3)-beta-D-glucans (GPBCD, GPECD, GP6CD, and GP3CD) having reducing glucose side chains were prepared from a linear (1-->3)-beta-D-glucan (curdlan: CD) with halogeno glucose isopropylidene derivatives in dimethyl sulfoxide containing dimsyl sodium, followed by treatment with 40% trifluoroacetic acid to remove protecting isopropylidene groups. The side chain glucose moiety was linked or directly or through a spacer at various positions except for its anomeric carbon.

Polysaccharides in fungi. XXXVIII. Anti-diabetic activity and structural feature of a galactomannan elaborated by Pestalotiopsis species

A fungus of Pestalotiopsis species produced an extracellular, water-soluble polysaccharide (PS-N). PS-N exhibited significant hypoglycemic activity in streptozotocin-induced diabetic mice following intraperitoneal administration and had an effect on oral glucose tolerance in normal mice following oral administration. PS-N ([alpha]D +34.5 degrees in water) was homogeneous on gel chromatography, it is composed of galactose and mannose in a molar ratio of 1:9, and its molecular weight was estimated by gel chromatography to be about 24,000. Its structure was investigated by a combination of chemical and spectroscopic methods. The results indicated that PS-N, a highly branched galactomannan, is composed of beta-(1-->3)-linked D-galactofuranosyl and non-reducing terminal beta-D-galactofuranosyl residues, in addition to alpha-D-mannopyranosyl residues of a yeast mannan type.

[Difference of blood cell counts with reference blood cell counters in different makers: Part II]

This is the second report of evaluation on the difference of blood cell counting among different automated blood cell counters in Japan. We tested reference blood cell counters of 6 different companies: Coulter, Sysmex, Bayer-Sankyo, Nihon Kohden, Horiba and Dainabot. Forty ml of whole blood were taken from 3 healthy persons and EDTA-2K anticoagulated blood samples (Sample 1, 2 and 3) were sent to each company to determine blood cell counts with a reference automated counter. As a result, the following items showed more than 10% difference among makers: RBC between Dainabot and Horiba in Sample 3, hematocrit values between Coulter and Dainabot in Sample 2, WBC between Nihon Kohden and each of three makers (Sysmex, Horiba and Dainabot) in all 3 samples and that between Bayer-Sankyo and each of two makers (Sysmex and Horiba) in Sample 3 and platelet count between Dainabot and each of 3 makers (Bayer-Sankyo, Nihon Kohden and Horiba) in all 3 samples. The following items showed difference between 5 and 10%: MCV between Coulter and each of two makers (Bayer-Sankyo and Horiba), WBC between each of two makers (Coulter and Nihon Kohden) and each of other 4 makers, and platelet count between each of two makers (Nihon Kohden and Horiba) and each of 3 makers (Coulter, Sysmex and Bayer-Sankyo). Recently Japanese Committee for Clinical Laboratory Standards proposed minimum clinical allowance of blood cell count as follows: hemoglobin 3%, RBC 4%, MCV 4%, WBC 7% and platelet count 10%. It is suggested that all of the items showing the difference more than above allowance among makers should be improved for clinical use to have good external quality control in blood cell counting by automated instruments.

Ionic current model of the vertebrate rod photoreceptor

We describe voltage- and calcium-dependent ionic currents in the photoreceptor inner segments similar to the Hodgkin and Huxley (Journal of Physiology, 117, 500-544, 1952) equations. The model is used to describe both rods and cones by adjusting parameters. To simulate the light response, the inner segment model was connected with the phototransduction model proposed by Torre et al. (Cold Spring Harbor Symposia on Quantitative Biology, 55, 563-573, 1990). The role of individual ionic currents in the inner segment in shaping the light response was analyzed through computer simulations. The results suggest that: (1) the transient hyperpolarization to a bright flash is generated by Ih; (2) the oscillation after prolonged hyperpolarization in rods results from the interaction among Ica, IK(Ca), and ICI(Ca). Since the present model describes the biophysical processes from phototransduction to voltage response, the model can be used for analyzing the light response properties of the photoreceptors quantitatively.

Ionic current model of bipolar cells in the lower vertebrate retina

We propose an ionic current model of bipolar cells based on the published experimental data. Five types of ionic currents identified in bipolar cell bodies, Ih, IKv, IA, ICa and IK(Ca) were described by a mathematical formulation similar to the Hodgkin and Huxley (Journal of Physiology, 117, 500-544, 1952) equations. The model parameters were estimated from the voltage clamp data. In simulation, we demonstrate that the present model reproduces not only the voltage clamp responses but also the current clamp responses of the bipolar cells. As a result, the model provides a better understanding of the functional role of the ionic currents in bipolar cells in generating the electrical responses.

Effect of 3-deoxyglucosone on the activities of enzymes responsible for glucose metabolism in mouse liver

Crude extracts containing the enzymes obtained from mouse liver were incubated with 3-deoxyglucosone (3-DG), and then subjected to assay of the activities of enzymes responsible for glucose metabolism. Hexokinase and glucose-6-phosphate dehydrogenase activities were decreased by 3-DG and hexokinase activity was strongly inhibited time and concentration dependently, while glucokinase, glucose-6-phosphatase, and phosphofructokinase activities were scarcely affected. These results suggest that 3-DG inhibits the intake of glucose in the liver and a connection with development of diabetes.

Reconstruction of retinal horizontal cell responses by the ionic current model

An ionic current model of the retinal horizontal cell is constructed. The horizontal cell models are interconnected by gap junctions to form a horizontal cell layer. The light response properties of the L-type horizontal cell are analyzed using this model. We demonstrate the functional role of each ionic current and the role of the feedback loop between cones and horizontal cells. The present study provides insight into the dynamic relationships between characteristics on the cellular level and on the multi-cellular level for producing the light response in horizontal cells.