Immunohistochemical study of hyaluronate receptor (CD44) in alcoholic liver disease

BACKGROUND

It has been suggested that the elevation of serum hyaluronate (HA) levels in liver diseases may be due to increased synthesis of HA by hepatic stellate cells or decreased degradation by sinusoidal endothelial cells. The increase in serum HA levels in patients with cirrhosis is thought to be a response to a reduction in HA receptors (CD44) in hepatic sinusoidal endothelial cells. To learn more about how alcohol affects the number and distribution of HA receptors of hepatic sinusoidal endothelial cells, we immunohistochemically studied CD44 levels in liver biopsy obtained from patients with alcoholic liver disease (ALD patients) and also from patients with nonalcoholic liver disease (non-ALD); ALD patients were evaluated when they were currently drinking and again after they became abstinent. Normal liver tissue obtained from three autopsy cases served as a control.

METHODS

Liver biopsy specimens were obtained from 18 ALD patients and 12 non-ALD patients. In ALD patients, liver biopsy was performed twice within 3 days and 4 to 8 weeks after abstinence when serum levels of aspartate aminotransferase and alanine aminotransferase became normal. CD44 in liver specimens was stained with anti-CD44 antibody by streptavidine-biotin-peroxidase complex. The intensity of the staining of CD44 in liver tissue was determined by a computer-assisted imaging analyzer. We also measured serum levels of CD44 in both ALD and non-ALD patients.

RESULTS

The intensity and the number of CD44 staining increased in both ALD and non-ALD patients compared with those in normal liver, which was negative. The staining intensity of CD44 in liver specimens obtained from patients with ALD who were active in alcohol consumption were significantly higher when compared with patients with ALD after abstinence. Serum levels of CD44 in patients with liver disease increased compared with those of healthy subjects.

CONCLUSIONS

The results suggest that HA receptors may increase to degrade the increased HA in serum and/or liver.

Severity of trauma changes expression of TNF-alpha mRNA in the brain of mice

BACKGROUND

The greater nitrogen loss that occurs with increasing severity of trauma is believed to occur because activation of the hypothalamus-pituitary axis is greater with severe injury. Cytokines in the brain stimulate the hypothalamus-pituitary-adrenal axis. This study was carried out to investigate whether the brain would recognize severity of trauma via TNF-alpha mRNA synthesis in the brain.

METHODS

Male C57BL/6 mice (n = 70, BW: 20-28 g) were randomly assigned into four groups, (1) control (no anesthesia or incision), (2) anesthesia alone, (3) anesthesia plus laparotomy by short incision (short), and (4) anesthesia plus laparotomy by long incision (long). A laparotomy was carried out in the short and long groups by a 1.2-cm vertical incision and by a horizontal plus a vertical incision (2.4 x 2.4 cm), respectively. Exactly either 3 or 24 h after surgery, the animals were decapitated. TNF-alpha mRNA levels in the tissues were determined by semi-quantitative PCR.

RESULTS

Nitrogen and catecholamine excretion were increased in the long wound group compared with the short wound group. Expression of TNF-alpha mRNA in the brain was greater in the long group after surgery than in the control, anesthesia, and short groups (brain, long: 0.150 +/- 0.005; P < 0.01 vs control, anesthesia alone, and short groups), but TNF-alpha levels in the plasma were the same in the short and long groups after surgery.

CONCLUSION

Levels of TNF-alpha mRNA in the brain were enhanced according to the length of the wound probably because of greater neural stimuli from the wound site, and this elevation was involved in the greater nitrogen loss.

Rapid tyrosine phosphorylation and activation of Bruton's tyrosine/Tec kinases in platelets induced by collagen binding or CD32 cross-linking

Stimulation of the platelet nonintegrin collagen receptor, glycoprotein VI, evokes a signaling response similar to that induced by antigen receptor activation in B and T lymphocytes. A key transducer of the lymphocyte signaling pathways is the Bruton's tyrosine kinase (Btk)/Tec kinase family, which connects receptors to the elevation of intracellular-free calcium levels. An important signaling function for Btk in collagen-induced platelet activation in vitro was recently demonstrated by other researchers using Btk-deficient platelets from patients with X-linked agammaglobulinemia (XLA). Since Btk-deficiency does not induce an overt platelet-based bleeding disorder in vivo, collagen receptor responses may include other Btk/Tec kinase family members in normal platelets. Both Btk and Tec had increased tyrosine following stimulation of collagen receptors or CD32 cross-linking. Data from kinetic analyses and inhibitor studies and the use of phosphopeptide-specific antibodies recognizing 2 Btk regulatory phosphorylated tyrosine residues suggest a mechanism for coordinate recruitment of Btk and Tec through the immunoreceptor tyrosine-based activation motif, Src family kinases, and phosphatidylinositol 3-kinase. In XLA platelets, collagen treatment increased tyrosine phosphorylation of Tec and several other signaling proteins, including Lyn, Fyb, Slp-76, and the Wiskott-Aldrich syndrome protein. This indicates that important elements of the collagen signaling pathway proximal and distal to Btk and Tec are preserved despite the lack of functional Btk. The results are consistent with the conclusion that activation of Tec may sustain XLA platelet function in vivo, while some in vitro assays of nonintegrin collagen receptor signaling through the Btk/Tec kinase family reflect the additive dosage of the transducers. (Blood. 2000;95:1663-1670)

Prebeta1-high-density lipoprotein (prebeta1-HDL) concentration can change with low-density lipoprotein-cholesterol (LDL-C) concentration independent of cholesteryl ester transfer protein (CETP)

To clarify whether prebeta1-high-density lipoprotein (prebeta1-HDL) concentration changes with low-density lipoprotein-cholesterol (LDL-C) concentration independent of cholesteryl ester transfer protein (CETP), we determined prebeta1-HDL concentration by native two-dimensional gel electrophoresis in 58 subjects with normal triglyceride and HDL-cholesterol concentrations. We also measured LDL-C and CETP concentrations. In 17 subjects, a second blood sample was taken 1-6 months after the first. We found that prebeta1-HDL concentration was positively correlated with LDL-C concentration (r=0.529, P<0.0001) and with CETP mass (r=0.398, P<0.01). In 17 patients, Deltaprebeta1-HDL was positively correlated with DeltaLDL-C (r=0.635, P<0.01), but not with DeltaCETP mass (r=0.275). In conclusion, prebeta1-HDL concentration changes with LDL-C concentration independent of CETP. These results suggest that prebeta1-HDL concentration may reflect the balance between several regulatory factors, including LDL-C and CETP concentrations.

Amino acid residues of S-modulin responsible for interaction with rhodopsin kinase

S-modulin in frog or its bovine homologue, recoverin, is a 23-kDa EF-hand Ca(2+)-binding protein found in rod photoreceptors. The Ca(2+)-bound form of S-modulin binds to rhodopsin kinase (Rk) and inhibits its activity. Through this regulation, S-modulin is thought to modulate the light sensitivity of a rod. In the present study, we tried to identify the interaction site of the Ca(2+)-bound form of S-modulin to Rk. First, we mapped roughly the interaction regions by using partial peptides of S-modulin. The result suggested that a specific region near the amino terminus is the interaction site of S-modulin. We then identified the essential amino acid residues in this region by using S-modulin mutant proteins: four amino acid residues (Phe(22), Glu(26), Phe(55), and Thr(92)) were suggested to interact with Rk. These residues are located in a small closed pocket in the Ca(2+)-free, inactive form of S-modulin, but exposed to the surface of the molecule in the Ca(2+)-bound, active form of S-modulin. Two additional amino acid residues (Tyr(108) and Arg(150)) were found to be crucial for the Ca(2+)-dependent conformational changes of S-modulin.

Blockade of vascular endothelial cell growth factor receptor signaling is sufficient to completely prevent retinal neovascularization

Retinal vasculogenesis and ischemic retinopathies provide good model systems for study of vascular development and neovascularization (NV), respectively. Vascular endothelial cell growth factor (VEGF) has been implicated in the pathogenesis of retinal vasculogenesis and in the development of retinal NV in ischemic retinopathies. However, insulin-like growth factor-I and possibly other growth factors also participate in the development of retinal NV and intraocular injections of VEGF antagonists only partially inhibit retinal NV. One possible conclusion from these studies is that it is necessary to block other growth factors in addition to VEGF to achieve complete inhibition of retinal NV. We recently demonstrated that a partially selective kinase inhibitor, PKC412, that blocks phosphorylation by VEGF and platelet-derived growth factor (PDGF) receptors and several isoforms of protein kinase C (PKC), completely inhibits retinal NV. In this study, we have used three additional selective kinase inhibitors with different selectivity profiles to explore the signaling pathways involved in retinal NV. PTK787, a drug that blocks phosphorylation by VEGF and PDGF receptors, but not PKC, completely inhibited retinal NV in murine oxygen-induced ischemic retinopathy and partially inhibited retinal vascularization during development. CGP 57148 and CGP 53716, two drugs that block phosphorylation by PDGF receptors, but not VEGF receptors, had no significant effect on retinal NV. These data and our previously published study suggest that regardless of contributions by other growth factors, VEGF signaling plays a critical role in the pathogenesis of retinal NV. Inhibition of VEGF receptor kinase activity completely blocks retinal NV and is an excellent target for treatment of proliferative diabetic retinopathy and other ischemic retinopathies.

fhit Alterations in endometrial carcinoma and hyperplasia

The fhit (fragile histidine triad) gene on chromosome 3p14.2 is a candidate tumour-suppressor gene; its abnormal transcripts are detected in several human cancers. To define the role of the fhit gene in the development of endometrial cancer, we examined 39 endometrial carcinomas for the presence of fhit gene alterations. fhit transcripts were analyzed by RT-PCR and direct sequencing. Loss of fhit transcript was observed in 6/39 (15%) tumours. Aberrant fhit transcripts, with deletions and/or insertions, were observed in 7/39 (18%) tumours but not in any normal endometrium. Allelic losses at D3S1300 and D3S4103, both located within intron 5 of fhit, were detected in 6/25 (24%) and 5/22 (23%) informative cases respectively. Expression of fhit protein was detected by immunohistochemistry; fhit protein was strongly expressed in 8/8 proliferative phase and 5/5 secretory phase endometria, also in 5/5 atrophic endometria; and it was strongly expressed in 6/6 simple hyperplasias without atypia, 6/6 complex hyperplasias without atypia, and II/II complex hyperplasias with atypia. In contrast, loss or reduced expression of fhit protein was observed in 13/27 (48%) endometrial adenocarcinomas. The impaired expression of the fhit protein was significantly correlated with the histological grade of the tumours. The present data suggest that inactivation of the fhit gene is an important genetic event associated with the genesis of endometrial carcinoma, especially with tumours of higher histological grade, which are believed to emerge directly from an atrophic endometrium.

Effect of surgical stress on endogenous morphine and cytokine levels in the plasma after laparoscopoic or open cholecystectomy

BACKGROUND

Endogenous morphine in the brain leads to various biological responses after surgery. The aim of this study was to determine whether morphine levels in the plasma would be enhanced by open laparotomy rather than by laparoscopic procedures.

METHODS

We compared 19 patients who underwent laparoscopic cholecystectomy with five patients who underwent resection of the gallbladder by open laparotomy. Morphine levels in the plasma were measured by an electrochemical detection system.

RESULTS

Postoperative endogenous morphine levels were higher with open laparotomy than with the laparoscopic technique (three h after surgery: open, 200 +/- 52.6 fmol/ml vs laparoscopy, 17.6 +/- 3.7, p < 0.01). This morphine elevation accounted for higher levels of cytokine, greater pain scores, and longer duration of fasting in open laparotomized patients than in laparoscopic cholecystectomy patients. Stress hormone levels in the plasma were also higher with open laparotomy than with laparoscopy.

CONCLUSION

Morphine synthesis was enhanced by open laparotomy, resulting in greater biological response postoperatively than that seen with laparoscopic cholecystectomy.

Organ-specific, carcinogen-induced increases in cell proliferation in p53-deficient mice

Transgenic mice with germ-line p53 alleles disrupted by gene targeting are sensitive to the development of some spontaneous tumors and have provided researchers with much information with respect to cancer. In the present study, to cast light on the organ specificity of chemically induced carcinogenesis, we evaluated carcinogen-induced cell proliferation in target organs in heterozygote p53 knockout mice (p53-deficient mice). Groups of 9- or 10-week-old wild-type(+/+) and p53-deficient mice were respectively treated with one of the following carcinogens for 4 weeks: N-butyl-N-(4-hydroxybutyl)nitrosamine (0.0075% in drinking water); dimethylnitrosamine (0.001% in drinking water); dihydroxy-di-N-propylnitrosamine (0.1% in drinking water); 1,2-dimethylhydrazine (10 mg/kg body weight s.c. injection once a week); 4-nitroquinoline 1-oxide (4-NQO, 10 mg/kg b.w. s.c. injection once a week); or 7,12-dimethylbenz(a)anthracene (25 microg/kg body weight dermal application once a week). Cell proliferation was evaluated by measuring the 5-bromo-2'-deoxyuridine labeling indices in each target organ. The p53 and p21 statuses were evaluated by comparing the expressions of p53 protein, p21waf1/cip1 mRNA, and p21waf1/cip1 protein between the mice. 5-Bromo-2'-deoxyuridine labeling indices of the urinary bladder and the skin were significantly increased in p53-deficient mice as compared with the wild-type(+/+) mice. In the all organs examined, carcinogen-induced p21waf1/cip1 mRNA overexpression was detected with levels obviously lower in the p53-deficient animals. These data suggest that p53-deficient mice have an organ-specific increased sensitivity to the induction of cell proliferation in the urinary bladder and the skin. These are the same organs for which sensitivity to carcinogenesis has been reported. Because a decrease of p21waf1/cip1 protein overexpression was also observed in the organs in which cell proliferation did not appreciably differ from the level in wild-type(+/+) mice, this decrease might have no effect on sensitivity to cell proliferation and carcinogenesis. Alternatively, it might play an important role in the cell cycle regulation of only the sensitive organs.

GAL4/UAS-WGA system as a powerful tool for tracing Drosophila transsynaptic neural pathways

Visualization of specific transsynaptic neural pathways is an indispensable technique for understanding the relationship between structure and function in the nervous system. Here, we demonstrate the application of the wheat germ agglutinin (WGA) transgene technique for tracing transsynaptic neural pathways in Drosophila. The intracellular localization of WGA was examined by immunoelectron microscopy. WGA signals were detected in granule-like structures in both the outer photoreceptor cells expressing WGA and the second-order laminar neurons. Misexpression of tetanus toxin (TNT), which inactivates N-synaptobrevin, in the outer photoreceptor cells resulted in the elimination of on/off transients in electroretinogram (ERG) recordings and in a great reduction in WGA transfer into laminar neurons, suggesting that anterograde WGA transsynaptic transfer is dependent mainly on synaptic transmission. Retrograde WGA transfer was also detected upon its forced expression in muscle cells. WGA primarily expressed in muscle cells was taken up by motoneuron axons and transported to their cell bodies in the ventral nerve cord, suggesting that WGA can trace motoneuronal pathways in combination with the muscle-specific GAL4 driver. Thus, the GAL4/UAS-WGA system should facilitate the dissection of the Drosophila neural circuit formation and/or synaptic activity in various regions and at various developmental stages.

FHIT alterations in cancerous and non-cancerous cervical epithelium

We have reported a significant frequency of an alteration of the fragile histidine triad (fhit) gene in squamous-cell carcinoma of the uterine cervix (series 1). To further define the role of fhit alteration in the development of cervical carcinoma, we surveyed 36 normal cervical epithelium, 22 cervical intra-epithelial neoplasias (CINs) and 20 additional cases of invasive cervical carcinomas (series 2). fhit transcripts were analyzed using reverse-transcription-polymerase-chain-reaction amplification and sequencing. Loss of expression of fhit was observed in 14 of 48 (29%) invasive carcinomas (8/28, series 1; 6/20, series 2) but not in any normal squamous epithelia or CINs analyzed. Abnormal fhit transcripts, including deletions and/or insertions, were observed in 12 of 48 (25%) invasive carcinomas (9/28, series 1; 3/20, series 2), 6 of 22 (27%) CINs, and 10 of 40 (25%) normal squamous epithelia (0/4, series 1; 10/36, series 2). Point mutation was detected in 9 of 48 (19%) cervical carcinomas (8/28, series 1; 1/20, series 2). Inactivation in both alleles was observed in 18 of 48 cervical carcinomas (38%), but not in any of 22 CINs or 40 normal squamous epithelia. Loss or impaired expression of the fhit-gene product was detected in 13 of 30 (43%) cervical carcinomas by immunohistochemistry, whereas all 6 normal cervical epithelia, or 22 CINs, expressed fhit protein. There was a strong association of impaired fhit protein expression with the disruption of normal fhit transcript in cervical carcinoma. No apparent correlation was observed between fhit inactivation and HPV infection. Our results suggest that fhit-gene inactivation occurs, not as an initiating event, but rather as a later event in cervical carcinogenesis, when the cervical tumor has acquired an invasive character.

Serum amyloid A protein generates pre beta 1 high-density lipoprotein from alpha-migrating high-density lipoprotein

Serum amyloid A protein (SAA), an acute-phase reactant in reactive amyloidosis, has high affinity for high-density lipoprotein (HDL). When SAA is added to HDL, SAA displaces apolipoprotein A-I (apoA-I) and phospholipid from the HDL particles. These dissociated components may form prebeta1-HDL because free apoA-I can associate with phospholipid to become a lipoprotein having prebeta mobility. To determine whether SAA generates prebeta1-HDL from alpha-migrating HDL, we investigated the effects of recombinant SAA on HDL subfraction concentration using nondenaturing two-dimensional gradient gel electrophoresis. When we added SAA (0.5 mg/mL) to plasma, the prebeta1-HDL concentration increased by 164% (from 4.7% +/- 1.3% to 12.4% +/- 3.2% of apoA-I, p < 0.005). The increase in prebeta1-HDL was proportional to the dose of SAA. When we added SAA to a column of Sepharose beads coupled to the isolated HDL (alpha-migrating HDL), prebeta1-HDL was dissociated from the column together with the SAA-associated HDL. In summary, we demonstrate that SAA generates prebeta1-HDL from alpha-migrating HDL. We speculate that SAA-mediated HDL remodeling may take place in inflammation.

Inhibitory effects of citrus essential oils and their components on the formation of N-nitrosodimethylamine

Twenty-eight kinds of citrus essential oils and their components were studied for inhibitory effects on the formation of N-nitrosodimethylamine (NDMA). The reaction mixture consisted of dimethylamine and sodium nitrite adjusted at pH 3.6, in addition to essential oils and an emulsifying agent. The quantification was determined by high-performance liquid chromatography monitored at 220 nm. All of the essential oils inhibited the formation of NDMA in the range of 20-85%. The oils of ujukitsu (Citrus ujukitsu Hort. ex Shirai), yuzu (C. junos Tanaka), mochiyu (C. inflata Hort. ex Tanaka), and ponkan (C. reticulata Blanco cv. F-2426) inhibited the formation of NDMA much more effectively than other citrus oils. The inhibitory proportions of components of citrus essential oils such as myrcene, alpha-terpinene, and terpinolene were as high as 80%.

An FH domain-containing Bnr1p is a multifunctional protein interacting with a variety of cytoskeletal proteins in Saccharomyces cerevisiae

Proteins containing formin homology domains, FH1 and FH2, are involved in cytokinesis or establishment of cell polarity in a variety of organisms. Bni1p and Bnr1p are FH proteins and potential targets of the Rho family small GTP-binding proteins in S. cerevisiae. We have shown that Bnr1p is localized at the bud neck to interact with Hof1p, involved in cytokinesis. We report here that the overexpression of BNR1 causes a cytokinesis deficiency which is similar to the phenotypes of the septin mutants, including cdc3, cdc10, cdc11, and cdc12. The region required for the septin mutant phenotypes was mapped to Bnr1p (35-500), which coincided with the region required for the bud-neck localization. To further isolate a gene interacting with BNI1 or BNR1, a multicopy suppressor of the bni1 bnr1 mutant was isolated. This gene encoded Smy1p, a kinesin-related protein. Bnr1p, but not Bni1p, directly interacted with the C-terminal region of Smy1p. The Smy1p-interacting region of Bnr1p was mapped to a region containing the FH2 domain. Bnr1p also directly interacted with Bud6p, a novel actin-binding protein. Bnr1p is thus a multifunctional protein which interacts with the septin system, a microtubule-dependent motor protein, and the actin system, to regulate cytoskeletal functions in S. cerevisiae.

Effect of intracerebroventricular injection of tumor necrosis factor alpha on gut mucosal protein turnover in mice fed enterally

OBJECTIVE

The objective of this study was to determine whether mucosal protein turnover is enhanced by intracerebroventricular (ICV) injection of tumor necrosis factor alpha (TNF-alpha) in mice fed enterally.

METHODS

Male B6C3F1 mice (n = 37, 20.0-25.0 g) were catheterized in the ICV space using stereotaxic coordination, and subsequently a catheter was inserted into the stomach for enteral feeding on Day 0. The animals were fed a standard mouse diet and water ad libitum for 4 days. On Day 4, enteral feeding was begun with a standard liquid diet, and either artificial cerebrospinal fluid (control) or recombinant human (Rh) TNF-alpha (5 ng/h) was continuously given via the ICV catheter using an osmotic pump. On either Day 5 or 7, the mice were sacrificed 10 min after injection of [U-(14)C]phenylalanine (5 microCi/mouse, ip). Fractional synthetic rates (FSRs) of jejunal mucosa and muscle were measured by the pool flooding technique. Interleukin-6 (IL-6) levels in the plasma were measured by ELISA.

RESULTS

Body weight was significantly reduced by ICV injection of TNF-alpha, because muscle FSR was decreased with TNF-alpha. There were no differences in IL-6 levels in the plasma between the two groups. The FSR of jejunal mucosa was elevated by infusion of TNF-alpha as compared with control mice on both Days 5 and 7 [Day 5: (control) 99.5 +/- 17. 6%/day vs (TNF) 150.5 +/- 20.5%/day, P < 0.05; Day 7: (control) 54.8 +/- 8.8%/day vs (TNF) 102.7 +/- 19.1%/day, P < 0.05).

CONCLUSION

injection of TNF-alpha enhanced the mucosal protein synthesis rate without elevating IL-6 levels as compared with control mice, suggesting that the central nervous system links to the gut to regulate mucosal protein turnover through cytokine in the brain, but plasma IL-6 is not involved in this linkage.

Isolation and mapping of a human lung-specific gene, TSA1902, encoding a novel chitinase family member

Using differential display technique, we have isolated a novel human gene expressed specifically in the lung. Two forms of the gene, designated TSA1902, were transcribed by alternate mRNA splicing. The transcribed mRNAs, termed TSA1902-L and TSA1902-S, putatively encode proteins of 368 and 315 amino acids, respectively, which show high similarity to human chitotriosidase protein. The N-terminal region of TSA1902-L protein contains the conserved active site residues (DXXDXDXE) of the catalytic center of various chitinases which are essential for chitinase activity. The deduced protein sequence of TSA1902-S, however, does not possess this active site, with the N-terminal 54 amino acids present in TSA1902-L protein having been deleted. Both proteins lacked the secretory sequence of N-termini and, judging from the hydropathy profile, may be soluble proteins in the cytoplasm. Chromosomal mapping by radiation hybrid analysis localized this gene to the chromosome 1p13.1-p21.3.

Complete cDNA sequence and genomic organization of a human pancreas-specific gene homologous to Caenorhabditis elegans sel-1

We have isolated the complete cDNA of a human SEL-1L gene, termed TSA305, that is abundantly expressed only in the pancreas. The cDNA contained an open reading frame of 2382 nucleotides, encoding a deduced protein of 794 amino acids whose predicted sequence showed 46% identity and 64% similarity with SEL-1 of Caenorhabditis elegans. SEL-1 is thought to be a negative regulator of the NOTCH, LIN-12, and GLP-1 receptors, which are required for differentiation and maturation of cells as well as cell-cell interactions during development in C. elegans. The degree of homology among these proteins suggests that the TSA305 gene product may be a member of the SEL-1 family and therefore involved in downregulation of mammalian Notch signaling. Direct sequencing revealed at least 20 coding exons in TSA305. We localized the gene to chromosome bands 14q24.3-q31 by radiation hybrid (RH) mapping and fluorescence in situ hybridization (FISH). The IDDM11 locus has been mapped in this region, and TSA305 may represent a candidate gene for predisposition in some families whose insulin-dependent diabetes is not linked to the HLA locus.

Thermostabilization by proline substitution in an alkaline, liquefying alpha-amylase from Bacillus sp. strain KSM-1378

alpha-Amylase (LAMY) from alkaliphilic Bacillus sp. strain KSM-1378 is a novel semi-alkaline enzyme which has 5-fold higher specific activity than that of a Bacillus licheniformis enzyme. The Arg124 in LAMY was replaced with proline by site-directed mutagenesis to increase thermostability of the enzyme. The wild-type and engineered LAMYs were very similar with respect to specific activity, kinetic values, pH-activity curve, and degree of inhibition by chelating reagents. Thermostability and structure stiffness of LAMYs as measured by fluorescence were increased by the proline substitution. The change of Arg124 to proline is assumed to stabilize the loop region involving amino acid residues from 122 to 134. This is the first report that thermostability of an alpha-amylase is improved by proline substitution.

Synthesis of taxoids 5. Synthesis and evaluation of novel water-soluble prodrugs of a 3'-desphenyl-3'-cyclopropyl analogue of docetaxel

A novel 3'-desphenyl-3'-cyclopropyl analogue of docetaxel was synthesized from 10-deacetyl-baccatin III. The cytotoxicity of the new taxoid was evaluated against several human tumor cell lines, and it had ca. 20 times stronger activity against human colon cancer cell lines (WiDr and Colon 320) than that of docetaxel. This taxoid was converted to its water-soluble prodrugs that have 2'-substituted amino acid derivatives with spacer. The prodrugs had good solubility in saline and showed more potent antitumor activity against B 16 melanoma in mice than that of docetaxel.

Signaling through fibroblast growth factor receptor 2b plays a key role in the development of the exocrine pancreas

The development of the pancreas depends on epithelial-mesenchymal interactions. Fibroblast growth factors (FGFs) and their receptors (FGFRs 1-4) have been identified as mediators of epithelial-mesenchymal interactions in different organs. We show here that FGFR-2 IIIb and its ligands FGF-1, FGF-7, and FGF-10 are expressed throughout pancreatic development. We also show that in mesenchyme-free cultures of embryonic pancreatic epithelium FGF-1, FGF-7, and FGF-10 stimulate the growth, morphogenesis, and cytodifferentiation of the exocrine cells of the pancreas. The role of FGFs signaling through FGFR-2 IIIb was further investigated by inhibiting FGFR-2 IIIb signaling in organocultures of pancreatic explants (epithelium + mesenchyme) by using either antisense FGFR-2 IIIb oligonucleotides or a soluble recombinant FGFR-2 IIIb protein. Abrogation of FGFR-2 IIIb signaling resulted in a considerable reduction in the size of the explants and in a 2-fold reduction of the development of the exocrine cells. These results demonstrate that FGFs signaling through FGFR-2 IIIb play an important role in the development of the exocrine pancreas.

Eosinophilic gastroenterocolitis in iron lactate-overloaded rats

Eosinophilic gastroenterocolitis with peripheral eosinophilia was induced in rats fed a diet containing 2.5% or 5.0% iron lactate for 3 mo. Additional findings consistent with iron overload were also observed. Microscopically, the lesions consisted of eosinophilic infiltrations in the mucosa and submucosa along the whole length of the gastrointestinal tracts, increased surface area of the gastric mucosal propria covered with mucous cells, and increased apoptotic bodies in the gastric glandular neck of rats in the 2.5% and 5.0% groups. An increased number of intraepithelial globule leukocytes in the gastric and intestinal lamina propria was also observed in the 5.0% group. Globule leukocytes in the gastric mucosa contained obviously enlarged granules in their cytoplasm in these rats. The granules of the globule leukocytes were positive for rat mast cell protease II, suggesting the mastocyte origin of these cells. Although severe infiltration of eosinophils and globule leukocytes suggested a type-1 hypersensitivity reaction, other features such as an increasing vascular permeability were not detected. Serum IgE levels in the 5.0% and control groups were < 3 ng/ml. Final body weights of male and female rats of the 5.0% group were suppressed to 70% and 90%, respectively, of those of the control rats, whereas food consumption was comparable to that of the control group. The morphologic characteristics of the gastrointestinal lesions and peripheral eosinophilia induced in rats fed iron lactate were very similar to those in some cases of eosinophilic gastroenterocolitis in humans and other animals.

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1997)]

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 17 institutions around the entire Japan, 512 strains of presumably etiological bacteria were isolated mainly from the sputa of 440 patients with lower respiratory tract infections during the period from October in 1997 to September in 1998. MICs of various antibacterial agents and antibiotics were determined against 100 strains of Staphylococcus aureus, 81 strains of Streptococcus pneumoniae, 85 strains of Haemophilus influenzae. 71 strains of Pseudomonas aeruginosa (non-mucoid strains), 27 strains of Pseudomonas aeruginosa (mucoid strains), 33 strains of Moraxella subgenus Branhamella catarrhalis, 17 strains of Klebsiella pneumoniae etc., and the susceptibilities of these strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 55.0%. The frequency of the drug resistant bacteria decreased comparing to the previous year's 67.3%. Arbekacin (ABK) and vancomycin (VCM) showed the most potent activities against MRSA. Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80S of 0.063 microgram/ml against S. pneumoniae. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP)+PC-resistant S. pneumoniae (PRSP) had decreased gradually, that is, in 1995 the frequency of it was 40.3%, but that was 30.9% in 1997. Against H. influenzae and M.(B.) catarrhalis, all the drugs showed good activities. But the sensitive strains of them against ceftazidime (CAZ) had decreased in 1997, compared those in 1995 and 1996. Meropenem (MEPM), IPM and tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains). And TOB and ciprofloxacin (CPFX) showed the most potent activities against P. aeruginosa (non-mucoid strains). All drugs except ampicillin (ABPC) were more active against K. pneumoniae in 1997 than that in 1996. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 45.5% of all the patients showing a slight increase year by year. About the proportion of diagnosed diseases, not so particular changes were recognized as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 33.6% and 29.1%, respectively. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these had reversed in bacterial pneumonia. The tendency in bacterial pneumonia had been acknowledged since 1995. The increase of S. aureus and P. aeruginosa (both mucoid and non-mucoid strains) isolated after administration of antibiotics, has suggested the decrease of the susceptibility of these strains against antibiotics. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 24.5%, H. influenzae 21.4%, S. aureus 18.4% and P. aeruginosa 12.2%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa was not affected. The frequencies of P. aeruginosa was 47.8% after administration over 15 days. From patients administered antibiotics of penicillins and cephems. S. aureus was mainly detected with 31.7-58.3%, and from patients administere

Evaluation of the pressure transfer system in the intracranial cavity by coherency

Coherency provides a method to evaluate model linearity. The characteristics of pressure wave transmission in the intracranial cavity were studied by coherency in 16 cats with hydrostatic pressure loading to assess the linearity of the system, which is an assumption for use of the transfer function. Linearity was observed in only the fundamental waves of the respiration-induced component and the cardiac-induced component of intracranial pressure oscillation, and in the second harmonic wave of the latter. Linearity at the other frequencies was close to zero. The pressure transfer system in the intracranial cavity was basically a non-linear system. As intracranial pressure rose, the increase in the pressure transfer efficiency was largest in the low-frequency domain and smallest in the high-frequency domain, indicating that the cerebral blood vessels are characterized by inferior transmission of high frequency due to increased intracranial pressure. In addition, the correlation between the coherencies of the cardiac-induced fundamental wave component and intracranial pressure, and between those of the cardiac-induced second harmonic wave component and intracranial pressure, showed that the slope of the straight line was greater between 45 and 70 mmHg than between 10 and 45 mmHg. This suggests that there is a break point, located between 45 and 70 mmHg, where the increase in the coherency values is accelerated, caused by an increase in the intracranial elastance, as well as an increase in the cerebrovascular compliance due to the reduced vascular transmural pressure.

Cardiomegaly in the juvenile visceral steatosis (JVS) mouse is reduced with acute elevation of heart short-chain acyl-carnitine level after L-carnitine injection

The long-term administration of L-carnitine was very effective in preventing cardiomegaly in juvenile visceral steatosis (JVS) mice, which was confirmed by heart weight as well as the lipid contents in heart tissue. After i.p. injection of L-carnitine, the concentration of free carnitine in heart remained constant, although serum free carnitine level increased up to 80-fold. On the other hand, a significant increase in short-chain acyl-carnitine level in heart was observed. These results suggest that increased levels of short-chain acyl-carnitine, not free carnitine, might be a key compound in the protective effect of L-carnitine administration in JVS mice.

[A case of emergency caesarean section as a result of anaphylaxis to latex]

A 32-year-old woman was admitted with a diagnosis of impending premature delivery. In the 37th week of pregnancy, vaginal examination was performed. After ten minutes, vomiting, whole body flushing, and cold sweat appeared suddenly. Because fetal heart rate became 60-70 beats.min-1, emergency caesarean section was scheduled. When she arrived at the operating room, blood pressure was 75/45 and heart rate was 122 beats.min-1. Five minutes later, anesthesia was induced with thiopental and vecuronium, and operation was instituted concomitantly. After the delivery, pentazocine and midazolam were administered. During the operation, premature separation of normally implanted placenta or pressed cord was not observed. Hydrocortisone was administered for circulatory collapse. Gabexate mesilate was administered for the prevention of DIC. The scratch test, performed ten days later, revealed that latex was positive but lidocaine was negative. Therefore, it was concluded that anaphylaxis induced by latex gloves caused shock after internal examination.

Hypoxia inducible factor-1alpha is increased in ischemic retina: temporal and spatial correlation with VEGF expression

PURPOSE

Hypoxia inducible factor-1 (HIF-1) is a transcription factor composed of HIF-1alpha and HIF-1beta subunits. HIF-1 transactivates multiple genes whose products play key roles in oxygen homeostasis, including vascular endothelial growth factor (VEGF). This study was designed to determine whether HIF-1 levels are increased in ischemic retina and whether there is a correlation with increased expression of VEGF.

METHODS

C57BL/6J mice were killed at time points that span retinal vascular development (PO to adult), or on postnatal day (P) 7 they were placed in a 75% oxygen environment for 5 days and then removed to room air and killed after 0, 2, or 6, or 24 hours and 5 or 14 days. Eyes were frozen, and retinas were isolated and used for immunoblot analysis, or eyes were sectioned for immunohisto chemical staining for HIF-1alpha or HIF-1beta, or for in situ hybridization for VEGF.

RESULTS

Immunoblots of retinal lysates showed low levels of HIF-1alpha at PO that were markedly increased at P4, remained high throughout the period of retinal vascular development and then decreased to an intermediate level in adults. HIF-1beta levels were relatively constant at all time points. In mice with oxygen-induced ischemic retinopathy, HIF-1alpha levels were increased in the retina. The peak of increase occurred at 2 hours, and levels returned to baseline by 24 hours. Immunohistochemistry showed increased staining for HIF-1alpha throughout the hypoxic inner retina, but not in the normoxic outer retina. There was no modulation of HIF-1beta levels. There was constitutive expression of VEGF mRNA in the inner nuclear layer that was increased 6 hours after the onset of hypoxia and remained elevated for several days.

CONCLUSIONS

There are increased levels of HIF-1alpha in ischemic retina that show temporal and spatial correlation with increased expression of VEGF. These findings are consistent with the hypothesis that HIF-1 plays a role in upregulation of VEGF in ischemic retina.

Isolation and mapping of a novel human kidney- and liver-specific gene homologous to the bacterial acetyltransferases

Using the differential display method to detect tissue-specific genes, we isolated a novel human gene, designated TSC501, that is expressed in kidney and liver. The cDNA contained an open reading frame of 681 nucleotides encoding 227 amino acids. The predicted product showed homologies in amino acid sequence to three different bacterial acetyltransferases, enzymes that are involved in drug resistance. Radiation hybrid mapping localized this gene to human chromosome bands 2p12-p13.1.

Thrombopoietin induces association of Crkl with STAT5 but not STAT3 in human platelets

Crkl, a 39-kD SH2, SH3 domain-containing adapter protein, is constitutively tyrosine phosphorylated in hematopoietic cells from chronic myelogenous leukemia (CML) patients. We recently reported that thrombopoietin induces tyrosine phosphorylation of Crkl in normal platelets. In this study, we demonstrate that thrombopoietin induces association of Crkl with a tyrosine phosphorylated 95- to 100-kD protein in platelets and in UT7/TPO cells, a thrombopoietin-dependent megakaryocytic cell line. With specific antibodies against STAT5, we demonstrate that the 95- to 100-kD protein in Crkl immunoprecipitates is STAT5. This coimmunoprecipitation was specific in that Crkl immunoprecipitates do not contain STAT3, although STAT3 becomes tyrosine phosphorylated in thrombopoietin-stimulated platelets. The coimmunoprecipitaion of Crkl with STAT5 was inhibited by the immunizing peptide for Crkl antisera or phenyl phosphate (20 mmol/L). After denaturing of Crkl immunoprecipitates, Crkl was still immunoprecipitated by Crkl antisera. However, coimmunoprecipitation of STAT5 was not observed. Coincident with STAT5 tyrosine phosphorylation, thrombopoietin induces activation of STAT5 DNA-binding activity as demonstrated by electrophoretic mobility shift assays (EMSA). Using a beta-casein promoter STAT5 binding site as a probe, we have also demonstrated that Crkl antisera supershift the STAT5-DNA complex, suggesting that Crkl is a component of the complex in the nucleus. Furthermore, interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and erythropoietin also induce Crkl-STAT5 complex formation in responding cells in a stimulation-dependent manner. In vitro, glutathione S-transferase (GST)-Crkl bound to STAT5 inducibly through its SH2 domain. These results indicate that thrombopoietin, IL-3, GM-CSF, and erythropoietin commonly induce association of STAT5 and Crkl and that the complex translocates to the nucleus and binds to DNA. Interestingly, such association between STAT5 and Crkl was not observed in cytokine-stimulated murine cells, suggesting an intriguing possibility that components of the human STAT5-DNA complex may be different from those of the murine counterpart.

Hypotensive mechanism of [Leu13]motilin in dogs in vivo and in vitro

The effects of [Leu13]motilin were examined in vivo after its intravenous administration into anesthetized dogs and in vitro with isolated preparations of canine mesenteric artery. [Leu13]Motilin (0.1-10 nmol x kg(-1), i.v.) induced both strong and clustered phasic contractions in the gastric antrum and duodenum. At doses of over 1 nmol x kg(-1), [Leu13]motilin also produced transient decreases in arterial blood pressure, left ventricular pressure, maximum rate of rise of left ventricular pressure, and total peripheral resistance, and an increase in aortic blood flow and heart rate. A selective motilin antagonist, GM-109 (Phe-cyclo[Lys-Tyr(3-tBu)-betaAla] trifluoroacetate), completely abolished the gastric antrum and duodenal motor responses induced by [Leu13]motilin. In contrast, hypotension induced by [Leu13]motilin (1 nmol x kg(-1)) was unchanged in the presence of GM-109. In isolated mesenteric artery preparations precontracted with U-46619 (10(-7) M), [Leu13]motilin (10(-8)-10(-5) M) induced an endothelium-dependent relaxation, and this was inhibited by a pretreatment with N(omega)-nitro-L-arginine, a competitive inhibitor of NO synthase (10(-4) M). A high dose (10(-4) M) of GM-109 slightly decreased [Leu13]motilin-induced relaxation, and shifted the concentration-response curve of [Leu13]motilin to the right. However, the pA2 value (4.09) of GM-109 for [Leu13]motilin in the present study was conspicuously lower than that previously demonstrated in the rabbit duodenum (7.37). These results suggest that [Leu13]motilin induces hypotension via the endothelial NO-dependent relaxation mechanism and not through the receptor type that causes upper gastrointestinal contractions.

Interaction of Bnr1p with a novel Src homology 3 domain-containing Hof1p. Implication in cytokinesis in Saccharomyces cerevisiae

Proteins containing the formin homology (FH) domains FH1 and FH2 are involved in cytokinesis or establishment of cell polarity in a variety of organisms. We have shown that the FH proteins Bni1p and Bnr1p are potential targets of the Rho family small GTP-binding proteins and bind to an actin-binding protein, profilin, at their proline-rich FH1 domains to regulate reorganization of the actin cytoskeleton in the yeast Saccharomyces cerevisiae. We found here that a novel Src homology 3 (SH3) domain-containing protein, encoded by YMR032w, interacted with Bnr1p in a GTP-Rho4p-dependent manner through the FH1 domain of Bnr1p and the SH3 domain of Ymr032wp. Ymr032wp weakly bound to Bni1p. Ymr032wp was homologous to cdc15p, which is involved in cytokinesis in Schizosaccharomyces pombe, and we named this gene HOF1 (homolog of cdc 15). Both Bnr1p and Hof1p were localized at the bud neck, and both the bnr1 and hof1 mutations showed synthetic lethal interactions with the bni1 mutation. The hof1 mutant cells showed phenotypes similar to those of the septin mutants, indicating that HOF1 is involved in cytokinesis. These results indicate that Bnr1p directly interacts with Hof1p as well as with profilin to regulate cytoskeletal functions in S. cerevisiae.

The metabolic pathway of visual pigment chromophore formation in Drosophila melanogaster--all-trans (3S)-3-hydroxyretinal is formed from all-trans retinal via (3R)-3-hydroxyretinal in the dark

Carotenoid-depleted fruit flies, Drosophila melanogaster, were reared on yeast/glucose medium containing lipid-depleted white corn grits and cholesterol. After rearing for more than a year, the yield of flies remained constant and the content of 3-hydroxyretinal in a head was three logarithmic units less than that of normal flies reared on medium containing yellow corn grits. When all-trans retinal was supplied as the sole source of retinoids, the flies formed and accumulated all-trans 3-hydroxyretinal in the dark. To examine the metabolic pathway to produce (3S)-3-hydroxyretinal in Drosophila, all-trans retinal was supplemented for two hours to carotenoid-depleted flies in the dark, and the subsequent changes in the composition of 3-hydroxyretinal enantiomers were analyzed using a chiral column on HPLC. The results indicated initial formation of (3R)-3-hydroxyretinal followed by isomerization into the 3S enantiomer. In another set of experiments, the membrane fraction was obtained from the head homogenate of retinoid-depleted flies and an in vitro assay of 3-hydroxyretinal formation from retinal was performed. The 3-hydroxyretinal produced was the 3R enantiomer, supporting the result obtained from the in vivo experiment whereby (3S)-3-hydroxyretinal is produced from retinal via (3R)-3-hydroxyretinal. Addition of NADPH enhanced 3-hydroxyretinal formation and the presence of carbon monoxide inhibited it, suggesting that hydroxylation at the C3 position of retinal occurred via the monooxygenase activity of cytochrome P-450.

Morphologic and hematologic characteristics of storage pool deficiency in beige rats (Chédiak-Higashi syndrome of rats)

Characterization of beige rats as having a platelet storage pool deficiency (SPD) was undertaken. Platelets from beige rats, an animal model of Chédiak-Higashi syndrome (CHS), completely lacked the ability to aggregate when stimulated with high dosages of collagen (50 micrograms/ml), and lacked secondary aggregation induced by adenosine diphosphate (ADP). Concentrations of ADP, ATP, and serotonin in the platelets of beige rats were significantly lower than those of control rats. However, platelet count remained within normal values. Electron microscopy revealed that platelets had fewer dense granules, whereas other organelles had normal structure. This morphologic and functional evidence confirms that platelets of beige rats have the typical characteristics of SPD.

Characterization of platelet abnormalities of Tester Moriyama (TM) rats with storage pool deficiency

Platelet abnormalities of Tester Moriyama (TM) rats, which have prolonged bleeding time with normal platelet count, were characterized by comparison with those of fawn-hooded (FH) rats with platelet storage pool deficiency (SPD). Morphologically, the dense granules were virtually lacking in platelets from TM and FH rats. Platelets from TM and FH rats aggregated in response to adenosine diphosphate (ADP), but failed to have secondary aggregation. In contrast, platelet aggregation was completely absent in response to 1 to 20 micrograms of collagen/ml, although partial aggregation was observed at the higher dosage of 50 micrograms/ml. Normal amounts of platelet membrane glycoproteins IIb/IIIa were expressed in TM and FH rats, but platelet adenosine triphosphate (ATP) and ADP contents were lower than those in platelets from control Wistar rats. Platelet ATP-to-ADP ratio of TM and FH rats was significantly higher than that of Wistar rats. Serotonin content in platelets from TM and FH rats was 20 to 25% that of Wistar rat platelets. These results suggested that platelet abnormalities of TM rats are a typical characteristic of platelet SPD and are similar to those of FH rats, which are genetically different from TM rats. Therefore, TM rats may serve as a useful animal model for the study of platelet SPD.

Expression and chromosomal localization of KIAA0369, a putative kinase structurally related to Doublecortin

Neuropathy in vertebrates can be a consequence of failure of genes involved in the nervous system to be expressed at the correct times and levels during embryonic life. Recently, a brain specific gene, Doublecortin, was cloned and was shown to have mutations in X-linked lissencephaly and double cortex syndrome. KIAA0369 is a putative kinase that is structurally related to Doublecortin. We compared the expression of KIAA0369 with that of Doublecortin, both of which were expressed specifically or predominantly in fetal brain among 20 different tissues examined. The deduced products of both genes contain a unique domain (the Doublecortin [DC] domain), but KIAA0369 also contains a calmodulin-dependent kinase (CaM kinase)-like domain following the DC domain. We found at least four splicing variants of KIAA0369: KIAA0369-AS (type A, short version), KIAA0369-AL (type A, long version), KIAA0369-BS (type B, short version), and KIAA0369-BL (type B, long version). KIAA0369-B, which lacked the DC domain and maintained the kinase domain, was expressed in adult as well as fetal brain, but the variants that included the DC domain, KIAA0369-A, were expressed predominantly in fetal brain. These results suggest that the DC domain plays an important role in the development of the nervous system. In the adult brain, KIAA0369 was expressed in all 15 different regions examined, more intensely in cerebral cortex, occipital pole, frontal lobe, amygdala, and hippocampus, and less intensely in corpus callosum and thalamus. The murine homologs of Doublecortin and KIAA0369 were not detectable in 7-day mouse embryos, but both genes were expressed extensively in 11-day embryos. Human KIAA0369 was mapped by fluorescence in situ hybridization (FISH) to chromosome 13q13-q14.1. The presence of genes related to neuropathy has been reported in this locus.

Collagen induces tyrosine phosphorylation of Wiskott-Aldrich syndrome protein in human platelets

Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are caused by mutations of the WAS protein (WASP) gene. All hematopoietic stem cell-derived lineages, including platelets, express WASP. Platelets from WAS patients are smaller than their normal counterparts and defects in platelet aggregation and actin polymerization have been reported. To determine if WASP is important for normal platelet function, we examined its role in signal transduction. We found that collagen but not thrombopoietin or thrombin induces a rapid and robust increase in tyrosine phosphorylation of platelet-associated WASP. Collagen-induced tyrosine phosphorylation of WASP was inhibited by cytochalasin D and wortmannin, respectively, suggesting that actin polymerization and phosphatidylinositol 3-kinase (PI3-kinase) play a role in the induction of tyrosine phosphorylation of WASP. Binding of glutathion S-transferase (GST)-Grb2 to WASP was seen in the lysate of resting platelets. The binding was reduced when lysates from collagen-stimulated platelets were incubated with GST-Grb2, suggesting that tyrosine phosphorylation of WASP may directly or indirectly modulate the adapter function of WASP. Although thrombin- and thrombopoietin-induced increase in tyrosine phosphorylation of WASP is negligible or marginal, WASP from thrombin-activated platelets became incorporated into the Triton X-100-insoluble 10, 000g sedimentable residue in an aggregation-dependent manner, suggesting that it may have a regulatory role in platelet cytoskeletal processes during aggregation. Lastly, we found that WASP is cleaved in response to activation of calpain, a protease that may have a role in postaggregation signaling processes. Our data suggest that collagen specifically induces an increase in tyrosine phosphorylation of WASP and that WASP is involved in signaling during thrombin-induced aggregation by its redistribution to the cytoskeleton and its cleavage during aggregation.

Hyperexpression of the gene for a Bacillus alpha-amylase in Bacillus subtilis cells: enzymatic properties and crystallization of the recombinant enzyme

We have constructed a new excretion vector, pHSP64, to develop a hyperexcretion system for Bacillus subtilis [Sumitomo et al., Biosci. Biotech. Biochem., 59, 2172-2175 (1995)]. The structural gene for a novel liquefying semi-alkaline alpha-amylase from the alkaliphilic Bacillus sp. KSM-1378 was amplified by PCR. It was cloned into a SalI-SmaI site of pHSP64 and the recombinant plasmid obtained was introduced into B. subtilis. The transformed B. subtilis hyperproduced the alpha-amylase activity extracellularly, corresponding to approximately 1.0 g (5 x 10(6) units) per liter of an optimized liquid culture. The recombinant enzyme was purified to homogeneity by a simple purification procedure with very high yield. No significant differences in physiochemical and catalytic properties were observed between the recombinant enzyme and the native enzyme produced by Bacillus sp. KSM-1378. The enzymatic properties of the recombinant enzyme were further examined with respect to the responses to various metal ions. The recombinant enzyme could easily be crystallized at room temperature within one day in a buffered solution of 10% (w/v) ammonium sulfate (pH 6.5).

High susceptibility of p53(+/-) knockout mice in N-butyl-N-(4-hydroxybutyl)nitrosamine urinary bladder carcinogenesis and lack of frequent mutation in residual allele

The loss of p53 functions is considered to compromise the growth-suppression machinery of the cell and facilitate neoplastic change. In humans, genetic alteration in the p53 gene is one of the most frequently observed molecular changes in tumors, including urinary bladder carcinomas. We have investigated the susceptibility of heterozygote p53 knockout mice to N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in terms of urinary bladder tumor induction. Both p53(+/-) knockout mice and C57BL/6 original parent strain were administered 0, 0.002, 0.004, 0.0075 and 0.025% BBN in the drinking water for 20 weeks. As compared with the C57BL/6 strain, greater lesion yields were observed in knockout mice after 20 weeks of treatment. Transitional cell carcinomas were found in 9 (75%) and 12 (100%) of each 12 mice of the 0.0075 and 0.025% BBN treatment groups, respectively, whereas only 1 (11%) and 6 (67%) of each 9 of the C57BL/6 mice demonstrated tumors. Preneoplastic lesions (dysplasia) were also observed more frequently in the lower dose groups in the knockout mice than C57BL/6 mice. PCR single-strand conformation polymorphism analysis followed by DNA direct sequencing of the p53 gene (exons 5-8) extracted from bladder tumors demonstrated mutations in 3 of 11 (27.3%; exon 7) and 8 of 29 (27.6%; exons 5-8) tumors in C57BL/6 and knockout mice, respectively. There was no significant difference in the mutation rates at the residual p53 gene between the two cases. All mutations observed in knockout mice were restricted to the normal allele, and none were present in the gene-targeted null allele. In a separate experiment, 5-bromo-2'-deoxyuridine labeling indices after treatment with BBN for 2 or 4 weeks were significantly higher in knockout mice than wild-type mice. Measurement of the urinary concentration of N-butyl-N-(3-carboxypropyl)nitrosamine, a proximate carcinogenic metabolite, revealed no significant differences between knockout and original parent strain after administration of 0.0075% BBN in the drinking water for 4 weeks. In conclusion, knockout mice are distinctly more sensitive to urinary bladder carcinogenesis induced by BBN than their original parent strain, as evidenced by elevated DNA synthesis during carcinogen administration and an increased tumor yield. The high susceptibility of p53 knockout mice appeared to be related to the high level of cell proliferation rather than that of N-butyl-N-(3-carboxypropyl)nitrosamine in the urine or that of mutations at the p53 gene.

Basic fibroblast growth factor is neither necessary nor sufficient for the development of retinal neovascularization

Basic fibroblast growth factor (FGF2) is constitutively expressed in the retina and its expression is increased by a number of insults, but its role in the retina is still uncertain. This study was designed to test the hypothesis that altered expression of FGF2 in the retina affects the development of retinal neovascularization. Mice with targeted disruption of the Fgf2 gene had no detectable expression of FGF2 in the retina by Western blot, but retinal vessels were not different in appearance or total area from wild-type mice. When FGF2-deficient mice were compared with wild-type mice in a murine model of oxygen-induced ischemic retinopathy, they developed the same amount of retinal neovascularization. Transgenic mice with a rhodopsin promoter/Fgf2 gene fusion expressed high levels of FGF2 in retinal photoreceptors but developed no retinal neovascularization or other abnormalities of retinal vessels; in the ischemic retinopathy model, they showed no significant difference in the amount of retinal neovascularization compared with wild-type mice. These data indicate that FGF2 expression is not necessary nor sufficient for the development of retinal neovascularization. This suggests that agents that specifically antagonize FGF2 are not likely to be useful adjuncts in the treatment of retinal neovascularization and therapies designed to increase FGF2 expression are not likely to be complicated by retinal neovascularization.

Enzymatic properties of a novel liquefying alpha-amylase from an alkaliphilic Bacillus isolate and entire nucleotide and amino acid sequences

A novel liquefying alpha-amylase (LAMY) was found in cultures of an alkaliphilic Bacillus isolate, KSM-1378. The specific activity of purified LAMY was approximately 5,000 U mg of protein-1, a value two- to fivefold greater between pH 5 and 10 than that of an industrial, thermostable Bacillus licheniformis enzyme. The enzyme had a pH optimum of 8.0 to 8.5 and displayed maximum activity at 55 degreesC. The molecular mass deduced from sodium dodecyl sulfate-polyacrylamide gel electrophoresis was approximately 53 kDa, and the apparent isoelectric point was around pH 9. This enzyme efficiently hydrolyzed various carbohydrates to yield maltotriose, maltopentaose, maltohexaose, and maltose as major end products after completion of the reaction. Maltooligosaccharides in the maltose-to-maltopentaose range were unhydrolyzable by the enzyme. The structural gene for LAMY contained a single open reading frame 1, 548 bp in length, corresponding to 516 amino acids that included a signal peptide of 31 amino acids. The calculated molecular mass of the extracellular mature enzyme was 55,391 Da. LAMY exhibited relatively low amino acid identity to other liquefying amylases, such as the enzymes from B. licheniformis (68.9%), Bacillus amyloliquefaciens (66.7%), and Bacillus stearothermophilus (68.6%). The four conserved regions, designated I, II, III, and IV, and the putative catalytic triad were found in the deduced amino acid sequence of LAMY. Essentially, the sequence of LAMY was consistent with the tertiary structures of reported amylolytic enzymes, which are composed of domains A, B, and C and which include the well-known (alpha/beta)8 barrel motif in domain A.

Isolation and characterization of a novel human lung-specific gene homologous to lysosomal membrane glycoproteins 1 and 2: significantly increased expression in cancers of various tissues

We have isolated and characterized a novel human lung-specific gene and observed its increased expression in cancers arising from various tissues. The cDNA, designated TSC403, contained an open reading frame of 1248 nucleotides encoding 416 amino acids; the deduced amino acid sequence showed significant similarities to lysosomal membrane glycoproteins (lamps) 1 and 2. We localized the gene to chromosomal band 3q27, a genomic region that is often amplified in human cancers of several tissue types. We detected a high level of the TSC403 transcript in primary cancers of the esophagus, colon, fallopian tube, ovary, breast, and liver, although expression of this gene was barely detectable in corresponding normal tissues. These findings indicated that up-regulation of the TSC403 transcript may be related to the development and/or progression of cancer in humans.

Alkaline detergent enzymes from alkaliphiles: enzymatic properties, genetics, and structures

The cleaning power of detergents seems to have peaked; all detergents contain similar ingredients and are based on similar detergency mechanisms. To improve detergency, modern types of heavy-duty powder detergents and automatic dishwasher detergents usually contain one or more enzymes, such as protease, amylase, cellulase, and lipase. Alkaliphilic Bacillus strains are often good sources of alkaline extracellular enzymes, the properties of which fulfil the essential requirements for enzymes to be used in detergents. We have isolated numbers of alkaliphilic Bacillus that produce such alkaline detergent enzymes, including cellulase (CMCase), protease, alpha-amylase, and debranching enzymes, and have succeeded in large-scale industrial production of some of these enzymes. Here, we describe the enzymatic properties, genetics, and structures of the detergent enzymes that we have developed.

Developmental study on reduction and kinks of the tail in a new mutant knotty-tail mouse

The knotty-tail (knt/knt) mouse has a short and knotty tail. The tail deformity is caused by a decrease in the number of caudal vertebrae and a deformity of them in the distal part of the tail. The objective of the study was to determine how reduction and kinks of the tail region were formed during secondary body formation. By day 12.0 pc, the somitogenesis of knt/knt embryos was completed; the number of caudal somites more or less agreed with those of the caudal vertebrae in knt/knt mice and were similar to those of knt/+ embryos. On the other hand, the somitogenesis of knt/+ embryos continued up to day 12.5 pc. The somites below about the sixth caudal somite were wedge-shaped with a dorsal apex in knt/knt embryos. The location of abnormal somites also corresponded well to that of deformed caudal vertebrae. Abnormal somitogenesis was always preceded by abnormalities in the presomitic region. Under gross observation, this could be seen to become markedly thickened, and histologically its dorsoventral diameter increased in the transverse plane on days 10.5-12.0 pc. In the mesenchyme there was often obvious cell death at the boundary of the unsegmented area and the tail bud after day 10.5 pc. These results suggested that the shortness of tail was primarily caused by the agenesis of distal caudal vertebrae following the agenesis of distal caudal somites, and partly by the disappearance of the presomitic part due to cell death, while the tail kinks were caused by the deformation of each caudal vertebra following disturbances of the caudal somites. Also, it is highly probable that the prominent cell death at the boundary of the unsegmented area and the tail bud may involve a defect or deformity of somites in this mutant.

Insulin receptor-related receptor in rat islets of Langerhans

The physiological aspects and roles of the insulin receptor-related receptor (IRR), a novel member of the insulin receptor family, are unknown. Published work shows a characteristic localization of IRR mRNA at the cellular level in the kidney, stomach and brain. In our previous study, a specific antibody against the rat IRR beta subunit was generated and used to identify the IRR-expressing cells as B-type intercalated cells in the kidney. In this study. IRR cDNA was amplified by PCR to demonstrate IRR mRNA expression in the rat pancreas. Immunohistochemical analysis with the anti-IRR antibody revealed that IRR immunoreactivity is localized in the islets of Langerhans. The IRR-immunoreactive cells were most likely to be the islet B cells which were stained with anti-insulin antibody. This is the first finding on the involvement of IRR in the physiological functions of insulin-secreting cells.

Improved thermostability of a Bacillus alpha-amylase by deletion of an arginine-glycine residue is caused by enhanced calcium binding

alpha-Amylase from alkaliphilic Bacillus KSM-1378 (LAMY) is a novel semi-alkaline enzyme which has a high specific activity, a value 5-fold higher than that of a Bacillus licheniformis enzyme at alkaline pH. Thermostability of this enzyme could be improved by deletion of the Arg181-Gly182 residue by means of site-directed mutagenesis. The wild-type and engineered LAMYs were very similar with respect to specific activity, pH-activity curve, temperature-activity curve, susceptibility to inhibitors, and pattern of hydrolysis products from soluble starch and maltooligosaccharides. However, the engineered enzyme also acquired increased pH stability and resistance to sodium dodecyl sulfate and especially chelating reagents, such as ethylenediaminetetraacetate and ethyleneglycol-bis (beta-aminoethylether)tetraacetate. This is the first report that thermostability of alpha-amylase is improved by enhanced calcium binding to the enzyme molecule.

Erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B in primary cultured human erythroid precursors

We examined signaling by erythropoietin in highly purified human colony forming unit-erythroid cells, generated in vitro from CD34(+) cells. We found that erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B. Tyrosine phosphorylation of Jak2 reaches a peak around 10 minutes after stimulation and is maximum at 5 U/mL of erythropoietin. Tyrosine phosphorylation of STAT5 is accompanied by the translocation of activated STAT5 to the nucleus as shown by electrophoretic mobility shift assay (EMSA) using 32Pi-labeled STAT5 binding site in the beta-casein promoter. Tyrosine phosphorylation STAT1 or STAT3 was not detected in human erythroid precursors after stimulation with erythropoietin. Crkl, an SH2/SH3 adapter protein, becomes coimmunoprecipitated specifically with STAT5 from erythropoietin-stimulated erythroid cells; although it was shown to become associated with c-Cbl in the studies using cell lines. Thus, human erythroid precursors can be expanded in vitro in sufficient numbers and purity to allow its usage in signal transduction studies. This report sets a basis for further studies on signaling in primary cultured human erythroid precursors, which in turn contribute to our better understanding in the differentiation processes of erythrocytes and their precursors.

Isolation and characterization of a novel human pancreas-specific gene, pancpin, that is down-regulated in pancreatic cancer cells

By means of the differential display method, we isolated a novel human gene that is expressed specifically in pancreas. The cDNA, designated "pancpin," contained an open reading frame of 1,215 nucleotides encoding a 405 amino acid protein, showing a high degree of similarity to serine protease inhibitors belonging to the serpin superfamily. To investigate its possible role in pancreatic carcinogenesis, we looked for genetic alterations of this gene in pancreatic cancer cell lines and primary pancreatic cancer tissues. Expression of pancpin was barely detectable in any of the four pancreatic cancer cell lines examined, and very weak also in 10 of 13 pancreatic cancer tissues. A somatic missense mutation at codon 221 was found in two of 16 primary pancreatic cancers. These findings indicate that down-regulation of pancpin expression may play a significant role in development or progression of pancreatic cancer.

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1996)]

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In 16 institutions around the entire Japan, 557 strains of presumably etiological bacteria were isolated mainly from the sputa of 449 patients with lower respiratory tract infections during the period from October 1996 to September 1997. MICs of various antibacterial agents and antibiotics were determined against 98 strains of Staphylococcus aureus, 93 strains of Streptococcus pneumoniae, 84 strains of Haemophilus influenzae, 84 strains of Pseudomonas aeruginosa (non-mucoid strains), 17 strains of Pseudomonas aeruginosa (mucoid strains), 31 strains of Moraxella subgenus Branhamella catarrhalis, 21 strains of Klebsiella pneumoniae etc., and the drug susceptibilities of these strains were assessed except for those strains that died during transportation. 1) S. aureus S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus) accounted for 67.3%. The frequency of the drug resistant bacteria increased comparing to the previous year's 52.7%. Arbekacin (ABK) and vancomycin (VCM) showed the highest activities against both S. aureus and MRSA with MIC80s of 1 microgram/ml. 2) S. pneumoniae Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80s of 0.063 microgram/ml. Faropenem (FRPM) showed the next potent activity with MIC80 of 0.125 microgram/ml. The other drugs except erythromycin (EM), clindamycin (CLDM) and tetracycline (TC) were active against S. pneumoniae tested with MIC80s of 8 micrograms/ml or below. 3) H. influenzae The activities of all drugs were potent against H. influenzae tested with MIC80s of 4 micrograms/ml or below. Cefotiam (CTM), cefmenoxime (CMX), cefditoren (CDTR) and ofloxacin (OFLX) showed the most potent activities with MIC80s of 0.063 microgram/ml. 4) P. aeruginosa (mucoid strains) Tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains) with MIC80 of 1 microgram/ml. Ceftazidime (CAZ), cefsulodin (CFS), IPM, gentamicin (GM), ABK and ciprofloxacin (CPFX) showed the next potent activities, with MIC80s of 2 micrograms/ml. The MIC80s of the other drugs ranged from 4 micrograms/ml to 16 micrograms/ml. 5) P. aeruginosa (non-mucoid strains) TOB and CPFX showed the most potent activities against P. aeruginosa (non-mucoid strains) with MIC80s of 1 microgram/ml. The MIC80s of piperacillin (PIPC) and cefoperazone (CPZ) were 16 micrograms/ml in 1995, and they were 64 micrograms/ml in 1996. 6) K. pneumoniae All drugs except ampicillin (ABPC) were active against K. pneumoniae. CMX, cefpirome (CPR), cefozopran (CZOP) and carumonam (CRMN) showed the most potent activities against K. pneumoniae with MIC80s of 0.125 microgram/ml. The MIC80s of the other drugs ranged from 0.25 microgram/ml to 2 micrograms/ml. 7) M.(B) catarrhalis Against M.(B.) catarrhalis, all drugs showed good activities with MICs of 4 micrograms/ml or below. IPM and minocycline (MINO) showed the most potent activities with MICs of 0.063 microgram/ml. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. Patients' backgrounds were examined for 557 isolates from 449 cases. The examination of age distribution indicated that the proportion of patients with ages over 60 years was 71.0% of all the patients showing a slight increase over that in 1994. Proportions of diagnosed diseases were as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 35.9% and 30.3% respectively. They were followed by bronchiectasis with a proportion of 10.