[Tonoko pneumoconiosis with deposition of titanium]

A 56-year-old man had worked as a furniture painter and had been exposed to tonoko polishing powder for 30 years. He had complained of dyspnea on exertion for 7 years, and was admitted to our hospital in 1991. A chest X-ray film revealed large opacities and emphysematous changes in both lung fields. Tonoko pneumoconiosis was diagnosed after transbronchial lung biopsy. Home oxygen therapy was given because of progressive hypoxemia, but the patient died of respiratory failure. At autopsy, examination of the lungs showed severe emphysematous changes, and collapse of alveoli. Many gray masses resembling coating cement were seen especially in the upper lobes. Microscopical examination showed that the large opacities were composed of hyaline nodules, similar to silicotic nodules, with anthracosis. Scanning electron microscopy with X-ray microanalysis revealed a high concentration of titanium in the gray mass. A low dose of titanium would not be expected to induce fibrotic changes in the lung, but a high dose and long-term exposure might have that effect. Titanium contained in paint might have exacerbated tonoko pneumoconiosis in this patient.

Determination of ultratrace amounts of copper (II) by its catalytic effect on the oxidative coupling reaction of 3-methyl-2-benzothiazolinone hydrazone with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline

A spectrophotometric method was developed for the determination of ultratrace amounts of copper(II) based on its catalytic effect on the oxidative coupling reaction of 3-methyl-2-benzothiazolinone hydrazone with N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline to produce an intensely coloured dye (lambda(max) = 525 nm) in the presence of hydrogen peroxide. In this reaction, pyridine acted as an effective activator for the catalysis of copper(II). By measuring the absorbance of the dye, copper(II) can be determined at the 0.002-0.1 ng cm(-3) (3.1 x 10(-11)-1.6 x 10(-9) mol dm(-3) level. The relative standard deviation for ten determinations of 0.06 ng cm(0-3) of copper(II) was 2.6%. The proposed method was successfully applied to the determination of copper(II) in tap water and biological material.

Seroepidemiological studies on Silk Road ethnic groups

To clarify the origin of the Japanese, the Jomom and/or Yayol, we screened for HTLV-1 and -II antibodies among inhabitants of the Silk Road, the Han, Uygur and Kazaks. We also screened for HIV, HBV, and HCV. The HTLV-I, -II, HIV, and HCV antibody tests were uniformly negative in all the studied groups. In contrast, a significantly higher incidence of HBs antigen was observed in all the groups tested (Northern Han: 11.9%, Uygur: 6.0%, Kazak: 9.1%). These results indicate that these ethnic groups are not the origin of the indigenous Japanese (the Jomon), and that HBV is prevalent in the various groups along the Silk Road.

Oesophageal cancer coexisting with colorectal lesions

OBJECTIVE

To investigate the incidence of colorectal lesions in patients who present with oesophageal cancer.

DESIGN

Prospective open study.

SETTING

University hospital, Japan.

SUBJECTS

135 of 218 patients who presented with squamous cell carcinoma of the oesophagus during the seven year period 1988-1994 were randomly allocated to have a barium enema examination.

INTERVENTIONS

Barium enema examinations, and if colorectal lesions were found, colonoscopy and biopsy.

MAIN OUTCOME MEASURE

Incidence of coexistent colorectal lesions.

RESULTS

No abnormal findings were found in 52 (39%), diverticula were present on 37 (27%), benign polypoid lesions in 51 (38%), and malignant lesions in 6 (4%). We examined the clinical and histopathological details of all patients to see if it was possible to distinguish the patients at high risk of developing oesophageal and colorectal cancer but could find no differences among the groups.

CONCLUSION

Asymptomatic colorectal lesions are relatively common in patients with squamous cell carcinoma of the oesophagus in Japan.

A carboxy-terminal deletion mutant of protein kinase C beta II inhibits insulin-stimulated 2-deoxyglucose uptake in L6 rat skeletal muscle cells

Alternative splicing of pre-mRNA encoding the carboxy-terminal (C-terminal) exons of protein kinase C beta (PKC beta) leads to the expression of two protein isoforms, PKC beta 1 and PKC beta II, with the potential for different functions. PKC beta II expression is regulated by insulin via alternative mRNA splicing. A physiological consequence of its activation was investigated in L6 rat skeletal muscle cells expressing GLUT4 transporters, a cell line in which PKC is involved in glucose transport. We examined the contribution of PKC beta II for insulin-stimulated [3H]2-deoxyglucose uptake by constructing three PKC beta II C-terminal deletion mutants designated M216, M217, and M218. When transiently expressed in COS1 cells, M217, with nine amino acids deleted, demonstrated autophosphorylation activity 10-fold less than full-length PKC beta II. The mutants M218, with 13 amino acids deleted, and M216, with 52 amino acids deleted, demonstrated no autophosphorylation activity and are kinase negative. When transiently expressed in L6 myotubes, M217 inhibited insulin-stimulated 2-deoxyglucose uptake by 45% (with a 45% transfection efficiency) whereas M216 and M218, kinase-negative mutants, had no effect compared with cells transfected with control plasmid. Cotransfection of full-length PKC beta II with M217 was able to rescue the inhibition of insulin-stimulated 2-deoxyglucose uptake as compared with cotransfection of M217 with the control plasmid, suggesting that M217 acts as a dominant-negative. In contrast, cotransfection of full-length PKC beta I, the other alternatively spliced form, did not rescue inhibition of insulin-stimulated 2-deoxyglucose uptake by M217. To further demonstrate the involvement of PKC, specifically PKC beta II, in insulin-stimulated 2-deoxyglucose uptake, we used two inhibitors, CG41251 (a specific PKC inhibitor) and CG53353 (a PKC beta II-specific inhibitor at 1 microM). Both inhibited insulin-stimulated 2-deoxyglucose uptake 50-60% in L6 myotubes. We conclude that M217 may act as a specific PKC beta II dominant-negative and that PKC beta II is more specific for insulin-stimulated 2-deoxyglucose uptake in these cells than PKC beta I.

Protein kinase C activates the MEK-ERK pathway in a manner independent of Ras and dependent on Raf

Although the involvement of protein kinase C (PKC) in the activation of the mitogen-activated protein (MAP) kinase pathway has been implicated through experiments using 12-O-tetradecanoylphorbol-13-acetate (TPA), there has been no direct demonstration that PKC activates the MAP kinase pathway. A Raf-dependent intact cell assay system for monitoring the activation of MAPK/ERK kinase (MEK) and extracellular signal-related kinase (ERK) permitted us to evaluate the role of PKC isotypes in MAP kinase activation. Treatment of cells with TPA or epidermal growth factor resulted in the activation of MEK and ERK. The activation of the MAP kinase pathway triggered by epidermal growth factor was completely inhibited by dominant-negative Ras (RasN17), whereas the activation triggered by TPA was not, consistent with previous observations. The introduction of an activated point mutant of PKCdelta, but not PKCalpha or PKCepsilon, resulted in the activation of the MAP kinase pathway. The activation of MEK and ERK by an activated form of PKCdelta requires the presence of c-Raf and is independent of RasN17. These results demonstrate that activation of PKCdelta is sufficient for the activation of MEK and ERK and that the pathway operates in a manner dependent on c-Raf and independent of Ras.

HLA-C genotyping of patient with Behçet's disease in the Japanese population

Behçet's disease has been known to be strongly associated with a particular HLA-B allele, B51. To address the possibility that the HLA-C gene, which is closely linked to HLA-B but has been poorly defined for allo-antigen specificity by the serologic method is involved in the susceptibility to Behçet's disease, HLA-C genotyping was performed for 90 Japanese Behçet's disease patients by the PCR-SSP method. The frequencies of HLA-Cw*14 and -Cw*15 were significantly higher in the patient with Behçet's disease as compared to the controls (48.9% vs. 24.0%, p = 0.0005, and 17.8% vs. 7.3%, p = 0.0434, respectively). On the other hand, the frequencies of HLA-Cw*0304 and -Cw*01 were significantly decreased in the patient group as compared to the control group (7.8% vs. 25.0%, p = 0.0027, and 23.3% vs. 37.5%, p = 0.0398, respectively). The significantly higher HLA-Cw*14 and -Cw*15 alleles may tightly correlate with the B51 antigen, and hence may have increased as a result of a linkage disequilibrium with B51. Accordingly, the HLA-C allele frequencies were compared for the B51-positive or -negative patients and controls, but there was no HLA-C allele showing a significant difference between these patient and control groups. Conversely, analysis of the HLA-B allelic distribution in association with HLA-Cw*14 revealed that in the healthy controls, B44 and B51 were present at the frequencies of 57.1% and 35.7% of the HLC-Cw*14-positive individuals, respectively. In contrast, in the Cw*14-positive patients the frequency of B44 was merely 14.0% (p = 0.0001) and that of B51 was significantly high, amounting to 82.0% (p = 0.0001). These facts suggest that the pathogenic gene of Behçet's disease is not the HLA-C gene (HLA-Cw*14 and/or HLA-Cw*15) but the HLA-B gene (HLA-B51) itself or a non-HLA gene residing in the centromeric side of the HLA-B gene rather than in the telomeric side around the HLA-C gene. This finding supports our previous mapping result, which located the susceptible gene between the TNF and HLA-B genes.

Protective effect of NG-monomethyl-L-arginine against hypotension inducted by combined tumour necrosis factor-alpha and whole body hyperthermia in rats

We studied: (a) the adverse effects of tumour necrosis factor-alpha (TNF) given during whole body hyperthermia (WBH) on mean arterial pressure (MAP) and gut mucosa in anaesthetized rats; (b) the potential protective effect of NG-monomethyl-L-arginine (L-NMA), an inhibitor of nitric oxide synthase; and (c) the influence of L-NMA on the antitumour effect of the trimodality therapy, WBH + TNF + Carboplatin (CBDCA). In normothermic rats, TNF alone (10(5) or 10(6) U/kg) did not cause hypotension, but increased MAP (p < 0.05). L-NMA alone (5, 10 and 20 mg/kg) increased MAP moderately and dose-dependently (p < 0.05). WBH (41.5 degrees C for 2 h) increased MAP markedly (from 103 +/- 4 to 161 +/- 4 mm Hg). This increase in MAP was sustained throughout the hyperthermia, but was followed by a transient relative hypotension (MAP = 80 +/- mm Hg) on cessation of WBH and an eventual return to near baseline at 30 min post-WBH (MAP = 94 +/- 5 mm Hg). WBH + TNF (10(5) or 10(6) U/kg) initially increased MAP similarly to WBH alone. During the second hour of WBH, however, MAP decreased towards pre-treatment levels, and cessation of WBH was followed by sustained hypotension. This late hypotensive state was associated with a mortality during the early (first 2 h) post-WBH period of 17 and 100% at TNF dose of 10(5) and 10(6) U/kg TNF, respectively. L-NMA given to rats receiving WBH + TNF (10(6) U/kg) maintained MAP at levels similar to WBH alone during WBH treatment. L-NMA prevented the post-WBH hypotension, and extended the survival beyond the early (first 2 h) post-WBH period. No rat, however, receiving high dose TNF (10(6) U/kg) survived more than 12 h even with L-NMA (totally 40 mg/kg). WBH + TNF (10(5) and 10(6) U/kg) also produced marked histopathological injury to the gut mucosa at 2 h post-treatment. L-NMA substantially protected the gut from this injury. In rats bearing a transplantable fibrosarcoma, L-NMA did not decrease the antitumour effect consisting of WBH + TNF (10(5) U/kg) + CBDCA, while it decreased (p < 0.05) the general toxicity (weight loss, diarrhea and foot oedema) of this combination. We conclude that L-NMA may prevent or ameliorate the early toxicity but not the late lethal effects of WBH + high dose TNF (10(6) U/kg). Additionally, L-NMA reduces some of the toxicity of WBH + TNF (10(5) U/kg) + CBDCA without decreasing the antitumour effect of this trimodality therapy. Inhibitors of nitric oxide synthase such as L-NMA may provide a novel approach to overcoming the toxicity of TNF in combination with WBH.

Analysis of HLA-DM polymorphisms in sarcoidosis

Sarcoidosis is a multisystemic granulomatous disorder showing significant increases in the HLA-DRB1*11, *12, *14 and *08 alleles in the Japanese population. To evaluate the role of polymorphism in the DMA and DMB genes in predisposition to sarcoidosis, seventy Japanese patients with sarcoidosis and 95 unrelated healthy controls were analyzed in the third exon polymorphisms within the DMA and DMB genes by the PCR-RFLP method. There were no differences in the distribution of DMA alleles between the patient and control groups. The frequency of DMB*0102 was higher (p < 0.05) and that of DMB*0101 was lower (p < 0.05) in the patients than in the healthy controls. However, this association and negative association could be explained by linkage disequilibrium with the disease-associated DRB1 alleles. The DMA and DMB genes do not primarily confer the susceptibility to sarcoidosis.

Genetic polymorphisms in the keratin-like S gene within the human major histocompatibility complex and association analysis on the susceptibility to psoriasis vulgaris

Psoriasis vulgaris is associated with the HLA-Cw6 and Cw7 antigens. However, it has not yet been clarified if the HLA-Cw6 and Cw7 genes themselves are the susceptible gene related to this disease or if it is some other non-HLA gene in a linkage disequilibrium with these HLA-C alleles. The S gene, recently identified in the HLA class I region 160 kb telomeric of HLA-C, encodes a keratin-like protein and is expressed specifically in the granular layer of the epidermis. Therefore, it is tempting to speculate that the S gene is one of the strong candidate genes responsible for the pathogenesis of psoriasis vulgaris. Direct sequencing of the first and second exon of the S gene after polymerase chain reaction (PCR) amplification has allowed the identification of two diallelic polymorphic sites in exon I and seven diallelic polymorphic sites in exon 2, three among which result in amino acid exchanges, a Ser-Phe substitution at amino acid position 186, a Gly-Val substitution at position 393 and a Ser-Leu substitution at position 394. No significant difference in the dimorphic distributions of the S gene was observed between the patients with psoriasis vulgaris and healthy controls, suggesting that the susceptible gene for psoriasis is not the S gene itself.

Breast lesions: correlation of contrast medium enhancement patterns on MR images with histopathologic findings and tumor angiogenesis

PURPOSE

To compare qualitative and quantitative magnetic resonance (MR) mammographic features of breast lesions with histopathologic findings, especially tumor angiogenesis.

MATERIALS AND METHODS

Seventy-three patients (72 women, one man; aged 30-78 years; mean age, 51.0 years) with suspicious breast lesions underwent MR imaging. Noncontrast medium-enhanced localization imaging and then gadolinium-enhanced dynamic fast spoiled gradient-recalled-echo (SPGR) imaging were performed in all patients. In selected patients, subtraction fast SPGR images were obtained. The Pearson and Spearman correlation tests were used to determine the strength of the relationships between enhancement parameters and microvessel determinations.

RESULTS

Time intensity curve type correlated with microvessel density grade (Spearman rank correlation test: r = .90, P < .001). The steepest slope of contrast medium uptake correlated with microvessel counts (Pearson correlation test; r = .83, P < .001). Peripheral enhancement in invasive carcinomas (n = 9) correlated with high peripheral and low central microvessel densities, which were associated with desmoplasia and/or necrosis. Internal septations (n = 2) were seen only in fibroadenomas.

CONCLUSION

The density and distribution of microvessels may play major roles in the determination of the initial rate of contrast medium uptake and the heterogeneity of tumor enhancement.

Rapid diagnosis of adenoviral conjunctivitis by PCR and restriction fragment length polymorphism analysis

To detect and identify adenovirus (Ad), we used a combination of PCR and restriction fragment length polymorphism (RFLP) analysis. Nested PCR with two primer sets that hybridize to the conserved region for hexon proteins of 14 prototypes of Ad, Ad serotype 1 (Ad1) to Ad8, -11, -14, -19, -37, -40, and -41, amplified a 956-bp DNA fragment. The amplified fragments from the 14 prototypes were completely differentiated with a combination of three restriction endonucleases, EcoT14I, HaeIII, and HintI. We applied this new method for 127 samples of conjunctival scrapings from patients with conjunctivitis and compared the results with those obtained with the combination of culture isolation and a neutralization test (NT). PCR gave a positive result in 69 of 127 cases (54.3%), while only 61 of the 127 samples (48.0%) tested positive by culture isolation. Compared with isolation, the PCR method had a sensitivity of 100% (61 of 61). Positive PCR samples were further classified as Ad37 (59.5%), -3(31.9%), -11 (4.3%), -8 (2.9%), and -4 (1.4%) by PCR-RFLP analysis. Of eight samples that were PCR positive and culture isolation negative, six were Ad37 and two were Ad8 by PCR-RFLP analysis. These differentiations of isolation-positive samples were identical to the results obtained by the NT. It took only 3 days to detect and identify Ad by PCR-RFLP analysis, whereas it took at least 3 weeks by culture isolation and NT. Our newly developed method of detecting and typing human Ad by PCR-RFLP analysis is more sensitive, accurate, and rapid than the conventional method of culture isolation and an NT.

The mixed lineage kinase SPRK phosphorylates and activates the stress-activated protein kinase activator, SEK-1

SPRK (also called PTK-1 and MLK-3), a member of the mixed lineage kinase subfamily of (Ser/Thr) protein kinases, encodes an amino-terminal SH3 domain followed by a kinase catalytic domain, two leucine zippers interrupted by a short spacer, a Rac/Cdc42 binding domain, and a long carboxyl-terminal proline-rich region. We report herein that SPRK activates the stress-activated protein kinases (SAPKs) but not ERK-1 during transient expression in COS cells; the p38 kinase is activated modestly (1.3-2 fold) but consistently. SPRK also activates cotransfected SEK-1/MKK-4, a dual specificity kinase which phosphorylates and activates SAPK. Reciprocally, expression of mutant, inactive SEK-1 inhibits completely the basal and SPRK-activated SAPK activity. Immunoprecipitated recombinant SPRK is able to phosphorylate and activate recombinant SEK-1 in vitro to an extent comparable to that achieved by MEK kinase-1. These results identify SPRK as a candidate upstream activator of the stress-activated protein kinases, acting through the phosphorylation and activation of SEK-1.

The notion of the Cambrian pananimalia genome

The toil by photosynthesizing cyanobacteria and blue-green algae of nearly three billion years appeared to have finally resulted in the sufficient accumulation of molecular oxygen. So, the stage was set for the emergence, at the ocean bottom, of diverse animals that were consumers of molecular oxygen. It now appears that this Cambrian explosion, during which nearly all the extant animal phyla have emerged, was of an astonishingly short duration, lasting only 6-10 million years. Inasmuch as only a 1% DNA base sequence change is expected in 10 million years under the standard spontaneous mutation rate, I propose that all those diverse animals of the early Cambrian period, some 550 million years ago, were endowed with nearly identical genomes, with differential usage of the same set of genes accounting for the extreme diversities of body forms. Some of the more pertinent genes that are thought to be included in the Cambrian pananimalia genome are as follows. (i) A gene for lysyloxidase that, in the presence of molecular oxygen, crosslinked collagen triple helices to produce ligaments and tendons, thus contributing to the stout bodies of the Cambrian animals. (ii) Genes for hemoglobin; these internal transporters of molecular oxygen are today seen sporadically in members of diverse animal phyla. (iii) The Pax-6 gene for eye formation; the eyes of a ribbon worm to a human are organized by this gene. In animals without eyes, the same gene organizes other sensory systems and organs. (iv) A series of Hox genes for the anterior-posterior (cranio-caudal) body plans: these genes are also present in all phyla of the kingdom Animalia.

Detection of enterovirus 70 by polymerase chain reaction in acute hemorrhagic conjunctivitis

PURPOSE

We have developed and applied reverse transcription-polymerase chain reaction for the detection of enterovirus 70 from conjunctival swabs of patients among the population of an acute hemorrhagic conjunctivitis epidemic on Okinawa, Japan, in 1994.

METHODS

The primers used were selected from the VP1, VP2, and VP3 regions of the enterovirus 70 nucleotide sequence.

RESULTS

Twelve of 27 culture-negative specimens were positive by reverse transcription-polymerase chain reaction.

CONCLUSIONS

The reverse transcription-polymerase chain reaction test provides a reliable diagnostic method that readily allows specific detection of enterovirus 70 in patients with acute hemorrhagic conjunctivitis in whom low enterovirus 70 recovery rates have been obtained recently by cell culture.

The prevalence of Toxoplasma antibody in patients with various ocular diseases in central Japan

BACKGROUND

Ocular toxoplasmosis has been considered to be a largely asymptomatic infection because of the high seroprevalence of Toxoplasma antibodies and the low rate of clinical diagnosis. On the other hand, Toxoplasma infection has been reported to be associated with the other ocular disease. To investigate the association of Toxoplasma infection with the development of various ocular diseases, we studied Toxoplasma seroprevalence in patients with various ocular diseases.

METHODS

We investigated Toxoplasma seroprevalence in 982 patients with various ocular diseases in central Japan. Then we compared the seroprevalence of anti-Toxoplasma antibodies.

RESULTS

Of 982 patients with various ocular diseases, 122 (12.4%) had serological evidence of previous exposure to Toxoplasma gondii. There were no statistically significant differences among the patients with various ocular diseases. However, the seroprevalence in patients aged 40 to 99 years with macular degenerative lesions was significantly higher than that in patients without these lesions (P < 0.05, Yates' correction).

CONCLUSION

This result suggests that Toxoplasma infection could play some role in the development of a type of macular degenerative lesion.

Immunogenetic studies of Behçet's disease

Behçet's disease has been shown to be strongly associated with the human leukocyte antigen (HLA) B51, not only in the Japanese but also in many other ethnic groups living in the area that extends from the Middle East to Japan. Specific antigen presentation by B51 molecules may be involved in the development of Behçet's disease. Furthermore, studies of the HLA-C genotype conducted using a polymerase chain reaction-sequence specific primers method have suggested that the gene involved in the pathogenesis of Behçet's disease is not the HLA-C gene but some other gene located near the HLA-B gene. Polymorphic analysis of the Tau-a microsatellite located between the HLA-B and TNF genes have also indicated that the Behçet's disease gene is located near the HLA-B gene but is not the HLA-B51 gene itself. We and others believe that many important genes exist in the region located between the TNF and HLA-B or HLA-C genes, including the MIC, PERB, and NOB genes. In this paper, we review current data on genetic factors involved in the development of Behçet's disease.

Proteoglycans in articular cartilage revealed with a quick freezing and deep etching method

OBJECTIVES

To clarify the three dimensional ultrastructure of proteoglycans, and their relationship with other matrix components in articular cartilage.

METHODS

Specimens from rat femoral heads were examined using three techniques: (1) Histochemical staining with cationic polyethyleneimine (PEI), using a pre-embedding or a postembedding method. Some tissues were pretreated with chondroitinase ABC or hyaluronidase. (2) Quick freezing and deep etching (QF-DE). Some specimens were fixed with paraformaldehyde and washed in buffer solution before quick freezing; others were frozen directly. (3) Ultrathin sections were studied after conventional preparation.

RESULTS

Proteoglycans were observed as aggregated clumps with PEI staining by the pre-embedding method, but as fine filaments by the postembedding method. They were lost with enzyme digestion; this was also demonstrated by the QF-DE method. The ultrastructure was well preserved by the QF-DE method when fixation and washing procedures were included, but not without these procedures. A fine mesh-like structure was connected to the cell membrane in the pericellular matrix. Filamentous structures suggestive of aggrecans were observed among collagen fibrils. They had side chains, approximately 50 nm in length, which branched from the central filaments at intervals of 10-20 nm, and were occasionally linked to other structures. Many thin filaments were also attached to the collagen fibrils.

CONCLUSIONS

The QF-DE method incorporating paraformaldehyde fixation and buffer washing procedures revealed three dimensional, extended structures suggestive of proteoglycans.

Three-dimensional ultrastructure of in situ membrane skeletons in human erythrocytes by quick-freezing and deep-etching method

The erythrocyte membrane skeleton is a network of some structural proteins, principally composed of spectrin, actin and protein 4.1, which is also attached to the cytoplasmic surface of the lipid membrane. The purpose of the present review is to describe the three dimensional ultrastructure of in situ membrane skeletons in human erythrocytes. The in situ membrane skeletons are densely organized, and the spectrin itself has a property of extension or contraction with reacting the external mechanical forces. The lengths between the intersections are changed according to the mechanical strength, and also vary even in one erythrocyte. To clarify the in situ organization of membrane skeletons, the quick freezing and deep-etching method should be used for fresh unfixed erythrocytes because of their fragility during preparation steps.

Dominant negative effect of the truncated p110 subunit of phosphatidylinositol-3 kinase

Effects of p110, the catalytic subunit of PI-3 kinase, on induction of TPA response element-driven promoter by EGF was examined. The induction was enhanced by co-expression of the wild type of p110. The truncated p110 mutants containing the binding site for p85 but missing the catalytic activity repressed the induction. A mutant with no binding activity to p85 did not show this effect. These results suggest that PI-3 kinase is involved in signal transduction of EGF and that the truncated p110s capable of binding to p85 serves as a dominant negative reagent for PI-3 kinase.

Monophyletic origin and unique dispersal patterns of domestic fowls

With the aim of elucidating in greater detail the genealogical origin of the present domestic fowls of the world, we have determined mtDNA sequences of the D-loop regions for a total of 21 birds, of which 12 samples belong to red junglefowl (Gallus gallus) comprising three subspecies (six Gallus gallus gallus, three Gallus gallus spadiceus, and three Gallus gallus bankiva) and nine represent diverse domestic breeds (Gallus gallus domesticus). We also sequenced four green junglefowl (Gallus varius), two Lafayette's junglefowl (Gallus lafayettei), and one grey junglefowl (Gallus sonneratii). We then constructed a phylogenetic tree for these birds by the use of nucleotide sequences, choosing the Japanese quail (Coturnix coturnix japonica) as an outgroup. We found that a continental population of G. g. gallus was the real matriarchic origin of all the domestic poultries examined in this study. It is also of particular interest that there were no discernible differences among G. gallus subspecies; G. g. bankiva was a notable exception. This was because G. g. spadiceus and a continental population of G. g. gallus formed a single cluster in the phylogenetic tree. G. g. bankiva, on the other hand, was a distinct entity, thus deserving its subspecies status. It implies that a continental population of G. g. gallus sufficed as the monophyletic ancestor of all domestic breeds. We also discussed a possible significance of the initial dispersal pattern of the present domestic fowls, using the phylogenetic tree.

An integrated microsatellite length analysis using an automated fluorescent DNA sequencer

Analyzing microsatellite instability (MI) in malignant tumors is thought to be useful for screening cancer patients to identify those patients with a higher risk of developing second malignant tumors. In this paper, we report a new, accurate, and efficient method of detecting MI using an automated fluorescent DNA sequencer and a computer that automatically calculates the size, height, and area of each fluorescent product, making it possible to assess MI more accurately and more rapidly. The primers for amplification of each microsatellite locus are labeled by two different fluorescent dyes, rox (red) and fam (blue). The rox-labeled primer was used for the tumor, whereas the fam-labeled primer was used for the corresponding normal tissue. Two amplified products from both the tumor and the normal tissue were co-loaded into a single lane of the sequencing gel and were analyzed. MI could be detected based on the presence of different waving patterns. Furthermore, several loci could also be analyzed simultaneously for MI in a single lane. Using this method, we examined the frequency of MI in gastric cancer. The results showed that 5 of 22 (22.7 %) gastric cancers were MI-positive, which corresponds to the findings of previous reports that used the radioisotopic method. The improved method may open up the possibility of performing routine examination of MI in many cancer patients and offers hope for the potential clinical application of Ml analysis as a follow-up evaluation of cancer patients.

Age of onset of posterior vitreous detachment

Recently published literature on the onset of posterior vitreous detachment is reviewed here. Aging causes posterior vitreous detachment, and its prevalence increases proportionally with age. The onset of posterior vitreous detachment is associated with refractive error. Investigation of the prevalence and onset age of posterior vitreous detachment indicates that the higher the degree of myopia, the earlier the onset age. There are some reports on the onset age of posterior vitreous detachment in men compared with women. One indicates that posterior vitreous detachment occurs earlier in women, and another reports no difference. No difference has been found between blacks and whites or between whites and Japanese.

An ultrastructural study of goblet cells in rat nasal mucosa as revealed by the quick-freezing method

In order to clarify the natural ultrastructure of goblet cells in the rat nasal mucosa, they were examined by the quick-freezing and freeze-substitution (QF-FS) or deep-etching (QF-DE) methods for comparison with conventional fixation methods. Some nasal mucosal tissues were unstimulated; others were stimulated with acetylcholine or substance P. The QF-FS method yielded fewer artefacts on transmission electron microscopy than conventional fixation methods. In the stimulated goblet cells, most of the secretory granules appeared to be loose in the matrix and more distorted in shape. By the QF-DE method, they were observed 3-dimensionally to be larger in size and aggregated together. In contrast, the secretory granules in the unstimulated goblet cells were mostly round and small, and separate from each other. It is concluded that the ultrastructure of secretory granules is artefactually modified by conventional fixation methods and that granule structure in goblet cells alters during the secretory process.

Effects of early insulin treatment on ultrastructural changes of glomeruli in diabetic rats revealed by the quick-freezing and deep-etching method

The three-dimensional ultrastructure of glomerular basement membrane (GBM) and mesangial matrix (MM) at an early stage of streptozotocin (STZ)-induced diabetes mellitus in rats was examined by the quick-freezing and deep-etching method. In diabetic rats, the GBM inner layer was diffusely enlarged and the meshwork structure not only in the GBM middle layer but also in the MM became markedly irregular due to the rupture of fine fibrils. This irregularity and enlargement of the mesh pores in diabetic rats developed during the experimental period and was significantly different from results in control rats. Insulin treatment from 1 week after STZ injection had significant effects in preventing the ultrastructural changes in the GBM and MM. It is suggested that early insulin treatment has significant effects in preventing size barrier disturbance of GBM and MM in STZ-induced diabetes.