Prevalence and clinical characterization of Japanese diabetes mellitus with an A-to-G mutation at nucleotide 3243 of the mitochondrial tRNA(Leu(UUR)) gene

An A-to-G mutation at nucleotide position 3243 of the mitochondrial genome has been associated with insulin-dependent diabetes mellitus (IDDM) and with noninsulin-dependent diabetes mellitus (NIDDM) with deafness. We investigated the prevalence of this mutation in Japanese patients with IDDM, NIDDM, and impaired glucose tolerance (IGT) and in nondiabetic control individuals, and we identified it in 3 of 300 patients with NIDDM or IGT (1.0%). None of these individuals had significant sensorineural hearing loss. None of the 94 IDDM or the 115 nondiabetic control subjects was positive for this mutation. Oral glucose tolerance test revealed that a 57-yr-old male with this mutation was rather hyperinsulinemic in the fasting state. The insulin secretion in this patient decreased with age; he did not complain of any hearing disorder, although audiometry revealed a slight elevation of hearing threshold at high frequencies. In conclusion, we found that a mitochondrial gene mutation at nucleotide position 3243 was present in about 1% of NIDDM patients including those patients with IGT. The subtype of diabetes mellitus with this mutation may have a clinical profile similar to that found in patients with NIDDM commonly seen in outpatient clinics.

Effect of saiko-ka-ryukotsu-borei-to on the stress-induced increase of serum corticosterone in mice

The effect of Saiko-ka-ryukotsu-borei-to (SRBT) on the stress-induced enhancement of serum corticosterone in various stress models was investigated in mice. The serum corticosterone was elevated significantly by immobilized stress, forced-swim stress, electric-shock stress, psychological stress and conditioned-fear stress, respectively. The concentration in the last two models was decreased in a dose-dependent manner by pre-administration of SRBT (10, 60, 100, 600 and 1000 mg/kg, p.o.). Therefore, this action seems to be effective in stress involving emotional factors but ineffective in physical stress models. These results indicate that the anti-stress effect of SRBT is dependent strongly on the degree of psychological change compared with physical change in mice.

Depressive effect of a traditional Chinese medicine (sho-saiko-to) on endotoxin-induced nitric oxide formation in activated murine macrophage J774A.1 cells

The present study investigated whether or not Sho-saiko-to (crude powder extract, TJ-9) can suppress nitric oxide (NO) generation by endotoxin-activated J774A.1 cells in order to study the preventive mechanism of Sho-saiko-to against endotoxemia. In this experiment, we estimated the NO2- in the murine macrophage cell line J774A.1 using the Griess method. Our results clearly demonstrated that J774A.1 cells stimulated with endotoxin (0.01-10 micrograms/ml) can effectively produce NO, and the production was dependent on the dose of endotoxin. On the other hand, we investigated the suppressive effect of TJ-9 (10-100 micrograms/ml) on NO generation by endotoxin (0.1 microgram/ml)-activated J774A.1 cells. The NO level when the cells were incubated with endotoxin and TJ-9 (10-20 micrograms/ml) was slightly lower than that in cells treated with endotoxin alone. In contrast, treatment with TJ-9 (50-100 micrograms/ml) significantly inhibited endotoxin-activated NO generation in J774A.1 cells, whereas the treatment with TJ-9 (10-100 micrograms/ml) alone was ineffective in inducing NO formation and in inhibiting cell viability in the J774A.1 cells. These findings suggest that a Kampo presciption of Sho-saiko-to shows a suppressive effect on NO generation in macrophages stimulated with endotoxin, and that it may be useful in improving endotoxin-shock symptoms.

Tyrosine phosphorylation of the proto-oncogene product Vav and its association with the adapter Grb2/Ash in a human leukemia cell line UT-7

The vav proto-oncogene product (Vav) is expressed exclusively in hematopoietic cells and is reported to have guanine nucleotide exchange activity. Here we report that granulocyte-macrophage colony-stimulating factor, interleukin-3, and erythropoietin induce tyrosine phosphorylation of Vav in a human leukemia cell line UT-7. Tyrosine phosphorylation of Vav is rapid and transient; it occurs within 1 min of the stimulation and at physiological concentrations of the factors. Furthermore, we show that Vav is constitutively associated with the adapter molecule Grb2/Ash in UT-7. These data suggest that tyrosine kinases, the adapter Grb2/Ash, and the guanine nucleotide exchange factor Vav are members of a signaling pathway leading to Ras activation in hematopoietic cells.

Erythropoietin induces tyrosine phosphorylation of the beta chain of the GM-CSF receptor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (EPO) induce tyrosine phosphorylation of the GM-CSF receptor beta chain and the EPO receptor, respectively, although their receptors lack the tyrosine kinase activity. We have shown that EPO as well as GM-CSF induces tyrosine phosphorylation of the beta chain. Conversely, GM-CSF does not induce tyrosine phosphorylation of the EPO receptor. Tyrosine phosphorylation of the beta chain by stimulation with EPO is rapid and transient. EPO may trans-modulate a signaling pathway of GM-CSF by phosphorylating the beta chain of the GM-CSF receptor.

Inhibition of specific binding of okadaic acid to protein phosphatase 2A by microcystin-LR, calyculin-A and tautomycin: method of analysis of interactions of tight-binding ligands with target protein

Several groups have reported that okadaic acid (OA) and some other tight-binding protein phosphatase inhibitors including microcystin-LR (MCLR), calyculin-A and tautomycin prevent each other from binding to protein phosphatase 2A (PP2A). In this paper, we have introduced an improved procedure for examining to what extent the affinity of an enzyme for a labelled tight-binding ligand is reduced by binding of an unlabelled tight-binding, ligand to the enzyme. Using this procedure, we have analysed the dose-dependent reduction of PP2A binding of [24-3H]OA by addition of OA, MCLR, calyculin-A and tautomycin. The results indicate that the binding of the unlabelled inhibitors to the PP2A molecule causes a dramatic (10(6)-10(8)-fold) increase in the dissociation constant associated with the interaction of [24-3H]OA and PP2A. This suggests that OA and the other inhibitors bind to PP2A in a mutually exclusive manner. The protein phosphatase inhibitors may share the same binding site on the PP2A molecule. We have also measured values of the dissociation constant (Ki) for the interaction of these toxins with protein phosphatase 1 (PP1). For MCLR and calyculin-A, the ratio of the Ki value obtained for PP1 to that for PP2A was in the range 4-9, whereas it was 0.01-0.02 for tautomycin. The value of tautomycin is considerably smaller than that (0.4) calculated from previously reported Ki values.

Flow cytometric analysis of p53 expression during the cell cycle

Mutant p53 expressed in many types of carcinoma lacks an inhibitory function on cell growth, but its role has been unclear. We performed two-parameter flow cytometry (FCM) to elucidate the relationship between the expression of p53 and the cell cycle in A431 cells. Fluorescence in situ hybridization proved that an A431 cell had two p53 genes whereas chromosome 17 was tetraploid. FCM showed that A431 cells expressed constantly high levels of p53 during the cell cycle. Under conditions of both serum deprivation and presence of hydroxyurea, p53 expression was decreased throughout the cell cycle, and the bivariate DNA/p53 distribution pattern during the cell cycle did not change. The expression of p53 was reduced to 60% for the first 4 h after the addition of cycloheximide, and showed no significant changes at least for 20 h. Treatment with Triton X-100 increased p53 immunoreactivity throughout the cell cycle. These results indicate that mutant p53 differs from proliferative markers such as PCNA, Ki-67 and DNA polymerase-alpha, and that there are no links between the expression of p53 and the cell cycle in A431 cells.

Changes in light scattering intensity of the transparent lenses of subjects selected from population-based surveys depending on age: analysis through Scheimpflug images

The physiological ageing changes of decreasing lens transparency were objectively evaluated in a total of 1,040 eyes selected from 1,685 individuals who were the subjects of population-based cataract epidemiological surveys performed in three climatically different survey fields in Japan. The lens transparency changes were evaluated from the light scattering intensity on thirteen different lens layers seen in slit images taken by the latest type of Scheimpflug camera. The mean percentage prevalence of cataracts in all the epidemiological survey subjects including grading from I to III, which was also judged objectively through documented images, was 64.6% in the Noto subjects, 46.6% in the Hokkaido subjects and 38.0% in the Okinawa subjects. The lens transparency at all of the measuring points decreased with ageing. The above changes, seen in the lenses of subjects in their 40s to 60s, were obviously more prominent compared with those seen in subjects in their 40s. Although there were some differences in transparency decrease with ageing among the subjects of the three areas, the authors tentatively propose to show the data obtained from the Noto subjects as representative of Japanese individuals. Lens transparency changes on each lens layer showed characteristic ageing changes and those of the representative four layers showed an exponential decrease in transparency. The decreasing ratio might accelerate from age as early as the mid-40s.

Determinations of marine toxins in foods

Prospects of new analytical methods for determining marine toxins in foods are described. The methods discussed include fluorometric liquid chromatography, cytotoxicity assays, channel binding assays, and enzyme-immunoassays. Emphasis was laid on assay methods for ciguatoxins and diarrhetric shellfish toxins.

Cell-to-cell interaction of cytokine-dependent myeloblastic line constitutively expressing membrane-bound stem cell factor abrogates cytokine dependency partially through granulocyte-macrophage colony-stimulating factor production

Stem cell factor (SCF) is a cytokine for hematopoietic progenitor cells and plays an important role in megakaryocyte proliferation. The UT-7 cell line was established from a patient with megakaryoblastic leukemia, and its growth and survival are strictly dependent on interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), erythropoietin (Epo), or IL-6. In this study, we showed that SCF also supported the growth of UT-7 in the absence of other cytokines and downregulated the cell surface c-kit receptors. Constitutive expression of SCF by introducing SCF expression vector made UT-7 grow factor-independently in liquid medium, but not in semisolid medium. This SCF-expressing factor-independent UT-7 (UT-7scf9) expressed the membrane bound form of SCF on their surface, but did not secrete detectable amounts of soluble SCF. UT-7scf9 formed aggregates as they grew in the absence of cytokines, and this aggregation was inhibited by adding soluble SCF into the medium. UT-7 cultured with SCF and UT-7scf9 cultured without cytokines expressed GM-CSF, and anti-GM-CSF neutralizing antibody partially inhibited their growth. These results suggest that SCF stimulated UT-7 proliferation partially through the autocrine-loop of GM-CSF, and UT-7scf9 expressed SCF mostly as a membrane-bound form, which transduces its growth signal through c-kit receptor as they aggregate by cell-to-cell interaction.

Population based cataract epidemiological surveys utilising a photodocumentation system

For the past 10 years, the authors have performed cataract epidemiological surveys in several places. All of them were principally population based and applied new types of photodocumentation systems which were developed by our department. The survey places in Japan were Noto, our main survey field located in the centre of the main island of Japan, one village in the subtropical island of Okinawa, a village in the northern island of Hokkaido and one village (Bukittinggi) in West-Sumatra, Indonesia, very close to the equator. The survey methods applied including an interview and ophthalmological examinations, were almost identical in each place and the authors believe that the quality of the examinations was at high level. The cataract classification and grading systems applied were those established by the Japanese Co-operative Cataract Epidemiology Study Group. At present, no significant prominent difference of cataract prevalence and distribution of cataract types have been found in the three Japan survey places. The distribution of cataract types in the Indonesian subjects however, was different from the Japanese subjects. The lens transparency ratio in the Noto survey was quite similar to that of a Dutch study. From photographic images of both opaque and transparent lenses much objective information which be cannot detected through naked eye observation is obtainable. Furthermore, data obtained from the images are comparable because of their objectivity. Although the methodology seems to be rather sophisticated and is costly, the above advantages make it an important asset in this type of cataract research. For example, lens transparency changes with ageing can be indicated quantitatively from image analysis data.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of E-cadherin-dependent cell-cell adhesion due to mutation of the beta-catenin gene in a human cancer cell line, HSC-39

Detachment of cell-cell adhesion is indispensable for the first step of invasion and metastasis of cancer. This mechanism is frequently associated with the impairment of either E-cadherin expression or function. However, mechanisms of such abnormalities have not been fully elucidated. In this study, we demonstrated that the function of E-cadherin was completely abolished in the human gastric cancer cell line HSC-39, despite the high expression of E-cadherin, because of mutations in one of the E-cadherin-associated cytoplasmic proteins, beta-catenin. Although immunofluorescence staining of HSC-39 cells by using an anti-E-cadherin antibody (HECD-1) revealed the strong and uniform expression of E-cadherin on the cell surface, cell compaction and cell aggregation were not observed in this cell. Western blotting (immunoblotting) using HECD-1 exhibited a 120-kDa band which is equivalent to normal E-cadherin. Northern (RNA) blotting demonstrated a 4.7-kb band, the same as mature E-cadherin mRNA. Immunoprecipitation of metabolically labeled proteins with HECD-1 revealed three bands corresponding to E-cadherin, alpha-catenin, and gamma-catenin and a 79-kDa band which was apparently smaller than that of normal beta-catenin, indicating truncated beta-catenin. The 79-kDa band was immunologically identified as beta-catenin by using immunoblotting with anti-beta-catenin antibodies. Examination of beta-catenin mRNA by the reverse transcriptase-PCR method revealed a transcript which was shorter than that of normal beta-catenin. The sequencing of PCR product for beta-catenin confirmed deletion in 321 bases from nucleotides +82 to +402. Southern blotting of beta-catenin DNA disclosed mutation at the genomic level. Expression vectors of Beta-catenin were introduced into HSC-39 cells by transfection. In the obtained transfectants, E-cadherin-dependent cell-cell adhesiveness was recovered, as revealed by cell compaction, cell aggregation, and immunoflourescence staining. From these results, it was concluded that in HSC-39 cells, impaired cell-cell adhesion is due to mutations in beta-catenin which results in the dysfunction of E-cadherin.

Basic performance of an organic dye-doped polymer optical fiber amplifier

A polymer optical fiber amplifier (POFA) of the graded-index (GI) type, with gain in the visible region, was successfully prepared for the first time, to our knowledge, with the interfacial-gel polymerization technique. An input signal of 0.85Wat 591 nm was amplified to 420W(27-dB gain) by injection of 690W of pump power at 532 nm into a GI POFA with a 0.5-m length. The efficiency of conversion of pump energy to signal amplification was more than 60%.

[Cataract epidemiology survey in the three climatically different areas in Japan--prevalence of cataracts and types of lens opacification]

A cataract epidemiology study of 1,615 subjects from three climatically different places in Japan, village S in Hokkaido, town M in Noto and village Y in Okinawa, was conducted by one study group. Cataract diagnosis and grading of cataracts were objectively done with a photo-documentation system. The percentages of cataracts of over grade I classified by the Japanese Cooperative Cataract Epidemiology Study Group were 46.6%, 64.6% and 38.0% in village S, town M, and village Y, respectively. Those in their 50s, 60s, and 70s in the above places were 24.3%, 51.1% and 71.4% (village S), 38.4%, 65.3% and 84.6% (town M), and 25.2%, 42.9% and 65.4% (village Y), respectively. Cortical cataract was the most common, followed by nuclear and subcapsular types. Although the highest percentage of nuclear cataracts was seen in the subjects of village Y, subcapsular cataract was seen almost equally in the three areas. Lens transparency changes were evaluated by the light scattering intensities in the lens layers through photographed images. Intensity increased with ageing either linearly or exponentially.

[The effect of local transient cooling on anodermal blood flow]

To clarify the regulatory mechanism of blood flow of anodermal mucosal layers responding to the localized and transient coolong stimulation (around -4 degrees C), we examined the change of anodermal blood flow with use of Laser Doppler Flowmeter (Periflux, Perimed). The cooling stimulation was applied to anoderm by the insertion of chilled cold stick (Poscool, Maruho) into the anus of 11 healthy male volunteer, aged 20-25 years. Experimental results obtained are as follow; 1) The anodermal blood flow of healthy subjects are variant in degree and widely distributed from 30 to 80 Perfusion Unit (PU). 2) After cooling for five minutes by the insertion of a frozen Poscool, anodermal blood flow were increased in 8 cases out of eleven (72.7%). The changes corresponds to be 1.4 to 5.2 times. 3) Eight cases are divided into two groups on the basis of the time course after cooling: the one is "delayed responding group" (there is a delay 10-40 minutes before the blood flow is increasing) and the other is "rapid responding group" (the blood flow is immediately increasing). These results indicate that the anodermal blood flow, which are exposed to cooling, of healthy subjects is regulated not only by nervous mechanism but by humoral mechanism. Then, based on the Lewis reaction (cold vasodilatation), it is suggested that the short time cooling of anoderm should be appreciated as a conservative therapy of hemorrhoids and anal fissures.

Reduced and oxidized forms of glutathione and alpha-tocopherol in the cerebrospinal fluid of parkinsonian patients: comparison between before and after L-dopa treatment

In the cerebrospinal fluid of untreated patients with Parkinson's disease (PD) the concentrations of reduced glutathione (GSH) and alpha-tocopherol (alpha-TOH) were unaltered but the concentration of oxidized glutathione (glutathione disulfide, GSSG) (P < 0.001), the GSSG/GSH ratio (P < 0.06), alpha-tocopherol quinone (alpha-TQ) (P < 0.001), and the alpha-TQ/alpha-TOH ratio (P < 0.01) were reduced significantly. In L-dopa-treated patients, the concentrations of GSH, GSSG, and the alpha-TQ concentration and the alpha-TQ/alpha-TOH ratio (P < 0.05) increased compared with untreated PD patients. These results suggest that oxidation of GSH and alpha-TOH is decreased in untreated PD patients, but is activated to a control level or more after L-dopa treatment.

Effects of acidic fibroblast growth factor on neuronal activity of the parvocellular part in rat paraventricular nucleus

The effects of acidic fibroblast growth factor (aFGF) and its amino-terminal and carboxyl-terminal fragments (aFGF(1-15) and aFGF(114-140), respectively were examined on the neuronal activity in the parvocellular part of the paraventricular nucleus. As well known, this part contains a lot of corticotropin-releasing factor (CRF)-immunoreactive neurons. Application of 1 pg/ml and 2 pg/ml aFGF produced responses in 29.7% and 46.7% of neurons tested, respectively. Half or more than half of the responding neurons increased their discharge rate. Application of 0.2 ng/ml and 0.4 ng/ml aFGF(1-15) (1-15) also elicited response in 46.2% and 68.8% of neurons tested, respectively. Of these responding neurons, more than two third increased their firing rate. However, most of neurons tested for 0.67 ng/ml and 1.33 ng/ml aFGF(114-140) did not respond. Results suggest that aFGF and aFGF(1-15) promote the release of CRF through the activation of CRF-containing neurons.

Morphological and biochemical changes in lenses of guinea pigs after vitamin-C-deficient diet and UV-B radiation

The effect of ultraviolet B (UV-B) radiation and a vitamin-C-deficient (VCD) diet on guinea pig lenses was investigated. The initial lens changes in the VCD group were observed by slit-lamp examination 6 weeks after the start of the VCD treatment; after 12 weeks the changes in the posterior subcapsular region became more prominent, and the dissociation around the posterior suture became wider and slightly deeper toward the posterior cortex. The high concentration of lens oxidized glutathione (GSSG), and the low ratio of reduced glutathione (GSH) to oxidized glutathione (GSH/GSSG) on the lens posterior region correlated with density changes in the corresponding layers as measured by Scheimpflug images with linear microdensitometry. It is suggested that the strong oxidative stress of the VCD diet caused the damage at the posterior part of the lens. UV-B radiation appeared to accelerate cataract progression in lenses that lack vitamin C.

An amino-terminal fragment peptide of acidic fibroblast growth factor modulates synaptic transmission in rat hippocampal slices

Effects of acidic fibroblast growth factor (aFGF) fragments such as aminoterminal aFGF (1-15) and carboxyl-terminal aFGF (114-140) on synaptic transmission were investigated in rat hippocampal slices. Stimulation was applied to Schaffer collateral/commissural afferents, and evoked population spikes were recorded in the CA1 pyramidal cell layer. Continuous perfusion of slices with aFGF (1-15) slightly decreased the basal amplitude of population spikes and significantly increased the paired-pulse facilitation. When brief tetanic stimulation (7 pulses at 100 Hz) was applied 30 min after the perfusion of aFGF (1-15), aFGF (1-15)-treated slices enhanced the magnitude of short-term potentiation after the tetanus and facilitated a generation of long-term potentiation. These effects of aFGF (1-15) were dose-dependent. Perfusion of slices with aFGF (114-140) had no effect on the basal spike amplitude, paired-pulse facilitation, and short-term potentiation. Both aFGF (1-15) and aFGF (114-140) had no effect on the DNA synthesis-stimulating activity in BALB/c 3T3-L1 cells. The results suggest that aFGF (1-15), which is not involved in mitogenic activity, is implicated in a modulatory mechanism of synaptic plasticity.

Evaluation of lens transparency changes through photographed images during a 13-month observation period

Since the development of the anterior eye segment analysis system, several new types of anterior eye segment biometry have been performed. The main aim of this study was to evaluate whether changes in cataractous progression or an increase in lens transparency loss are detectable during a relatively short period of 13 months by measuring the intrapupillary opaque shadow area through retroillumination images or by calculating the light scattering intensity at the deepest cortical layer of the lens through Scheimpflug slit images. Secondly, the relationship between maximally dilated pupil sizes and patients' ages and that between cases with and without diabetes were studied. Thirty-one eyes (49.2%) of sixty-three cataractous lenses showed more than 5% increase in the opaque shadow area. Forty-five eyes (60.0%) showed more than a 5% increase in light scattering intensity. 92.5% of diabetic eyes and 92.3% of nondiabetic eyes showed pupil sizes over 6.5 mm after an instillation of mydriatica. In our study the applied method guaranteed a high reproducibility; thus is might be possible to detect an increase in cataractous changes and lens transparancy in around 50% of examined subjects in a period as short a 1 year. For the evaluation of cataract progression through a retroillumination image, the recommendable pupil size is > or = 6.5 mm.

Computed tomographic images and three-dimensional expression of crystalline lens findings from multiple slices of Scheimpflug slit images

Although the observation of lens changes in clinical examination has been made through a slit lamp microscope under dilated pupil, precise documentation and analysis of lens changes are presently possible through Scheimpflug photographic images. However, the methodology is still unsatisfactory because the image analysis is two dimensional. In order to overcome this disadvantage, the authors aimed at developing a new methodology for obtaining computed tomographic images of the lens. 60 Scheimpflug slit images of a cataractous human lens were taken by an anterior eye segment analysis system as digital data. After the locations of the whole slit images had been matched, reconstruction of the coronal section line images was performed utilizing extracted image information. The total number of reconstructed coronal section images in additional procedures of the image interpolation was 150. Computed tomography of the lens image was made from those 150 images. A whole lens figure was also demonstrated as a moving three dimensional image.