Acute disseminated encephalomyelitis confined to brainstem

A 21-year-old man was troubled with a subacute history of brainstem involvement and a leukocyte pleocytosis in the cerebrospinal fluid. Magnetic resonance imaging (MRI) demonstrated a massive lesion with Gd enhancement in the pons. Steroid therapy, not antiviral drugs, was dramatically effective for the mass reduction and symptom improvement. Over 4 years no recurrence has been recognized, so this case was diagnosed to be an unusual case of acute disseminated encephalomyelitis (ADEM). ADEM must be included in the differential diagnosis for a brainstem mass in MRI.

The NEDD8 system is essential for cell cycle progression and morphogenetic pathway in mice

NEDD8/Rub1 is a ubiquitin (Ub)-like molecule that covalently ligates to target proteins through an enzymatic cascade analogous to ubiquitylation. This modifier is known to target all cullin (Cul) family proteins. The latter are essential components of Skp1/Cul-1/F-box protein (SCF)-like Ub ligase complexes, which play critical roles in Ub-mediated proteolysis. To determine the role of the NEDD8 system in mammals, we generated mice deficient in Uba3 gene that encodes a catalytic subunit of NEDD8-activating enzyme. Uba3(-/-) mice died in utero at the periimplantation stage. Mutant embryos showed selective apoptosis of the inner cell mass but not of trophoblastic cells. However, the mutant trophoblastic cells could not enter the S phase of the endoreduplication cycle. This cell cycle arrest was accompanied with aberrant expression of cyclin E and p57(Kip2). These results suggested that the NEDD8 system is essential for both mitotic and the endoreduplicative cell cycle progression. beta-Catenin, a mediator of the Wnt/wingless signaling pathway, which degrades continuously in the cytoplasm through SCF Ub ligase, was also accumulated in the Uba3(-/-) cytoplasm and nucleus. Thus, the NEDD8 system is essential for the regulation of protein degradation pathways involved in cell cycle progression and morphogenesis, possibly through the function of the Cul family proteins.

Inhibitory effect of somatostatin on cholecystokinin release is independent of luminal cholecystokinin-releasing factor content in conscious rats

INTRODUCTION

Exclusion of bile-pancreatic juice from the intestine increases pancreatic secretion via cholecystokinin (CCK) release in conscious rats. Luminal CCK-releasing factor (LCRF), purified from rat intestinal secretions, is an intraluminal regulator of CCK secretion during bile-pancreatic juice diversion.

AIMS

Because somatostatin is a potent inhibitor of CCK release and pancreatic secretion, the inhibitory effect of somatostatin on LCRF was examined.

METHODOLOGY

Rats were prepared with bile and pancreatic cannulae and two duodenal cannulae and with an external jugular vein cannula. The experiments were conducted without anesthesia. After 1.5-hour basal collection of pancreatic juice with bile-pancreatic juice return, bile-pancreatic juice was diverted for 2 hours, during which time somatostatin (2, 10 nmol/kg/h) was infused intravenously. The rats were killed before and 1 and 2 hours after bile-pancreatic juice diversion. To examine the effect of luminal somatostatin, 50 or 200 nmol/kg/h of somatostatin was infused into the duodenum. The plasma CCK and luminal content of LCRF were measured by specific radioimmunoassays.

RESULTS

Bile-pancreatic juice diversion significantly increased pancreatic secretion, plasma CCK, and LCRF levels. Intravenous infusion of somatostatin inhibited CCK release and pancreatic secretion, but not LCRF content. Luminal administration of somatostatin did not show any effect.

CONCLUSION

Inhibitory effect of circulating somatostatin on CCK release and pancreatic secretion is independent of LCRF content.

Target gene therapy for alpha-fetoprotein-producing hepatocellular carcinoma by E1B55k-attenuated adenovirus

Gene therapy using replication-competent adenovirus that selectively propagates in tumor cells may be an effective treatment for cancer. We developed an adenovirus that would be replication specific for hepatocellular carcinoma (HCC). Based on our finding that the E1B55k-deficient adenovirus was able to replicate in human primary hepatocytes, we therefore designed an adenovirus carrying E1A and attenuated E1B gene driven by the alpha-fetoprotein promoter (Adv-AFP-E1AdB), thus restricting the replication specificity in AFP-producing HCC. Replication of Adv-AFP-E1AdB in primary hepatocytes was practically negligible 4 days after infection. Although Adv-AFP-E1AdB replicated slowly in AFP-producing HCC, it efficiently destroyed HCC cells independent of their p53 status. Experiments were conducted in vivo using systemic administration of Adv-AFP-E1AdB and we observed tumor size reduction in nude mice having liver cancer. The use of replication-competent adenovirus deficient of the E1B gene coupled to an AFP-targeting strategy may be a safe and efficacious treatment for HCC.

Control of IkappaBalpha proteolysis by the ubiquitin-proteasome pathway

It has recently been determined that the proteolytic destruction of IkappaB (inhibitor of NF-kappaB) by the ubiquitin-proteasome system plays a key role in the immediate elimination of IkappaB from the IkappaB-(NF-kappaB) complex which allows nuclear translocation of free NF-kappaB, thus leading to activation of a multitude of target genes. The SCF(Fbw1) (composed of Skp1, Cul-1, Roc1, and Fbw1) complex, identified as an IkappaBalpha-E3 ligase, binds and ubiquitylates IkappaBalpha phosphorylated by IkappaB kinase that has been activated in response to extracellular signals. The generating poly-ubiquitin chain is finally recognized by the 26S proteasome for ultimate degradation. In this NF-kappaB signalling pathway, it becomes clear that the SCF(Fbw1) activity is enhanced by a ubiquitin-like protein NEDD8 (equivalent to Rub1) that modifies Cul-1 in a manner analogous to ubiquitylation, and consequently, IkappaBalpha proteolysis is induced. NEDD8 is a new regulator of the SCF ubiquitin-ligase, functioning as a covalent modifier for proteolytic targeting at a physiological level.

S20G mutant amylin exhibits increased in vitro amyloidogenicity and increased intracellular cytotoxicity compared to wild-type amylin

Human amylin, a major constituent of pancreatic amyloid deposits, may be a pathogenetic factor for noninsulin-dependent diabetes mellitus (NIDDM). We demonstrated that the human amylin S20G gene mutation (S20G) was associated with a history of early onset, more severe type of NIDDM, linking the amylin gene to this disease. Also, we demonstrated that expression of human wild-type (WT) amylin in COS-1 cells leads to intracellular amyloidogenesis and induction of apoptosis, suggesting a possible mechanism for disease induction. Therefore we compared the abilities of S20G and WT amylin to induce apoptosis in transfected COS-1 cells and form amyloid in vitro. We transfected the rat (RAT), mutated human (MUT), WT, and S20G amylin genes into COS-1 cells and measured apoptosis using fluorescent-activated cell sorting analysis at 48, 72, and 96 hours. At 96 hours apoptosis increased significantly (P < 0.01) in cells transfected with WT and S20G over RAT or MUT (WT, 19%; S20G, 25%; RAT, 13%; and MUT, 12%) and the difference between WT and S20G was significant (P < 0.05). Synthetic WT and S20G monomeric peptides were used to generate amyloid fibrils in vitro as measured by the thioflavin T binding assay. The S20G amylin formed approximately twofold more amyloid at a rate approximately threefold higher than WT. Electron micrography indicated that the in vitro amyloid generated by WT and S20G amylins were morphologically indistinguishable. The results suggest that increased cytotoxicity by S20G is because of increased amyloidogenicity, which may be a causative factor in the early development of NIDDM, possibly through loss of ss cell mass.

High proportion of mutant K-ras gene in pancreatic juice of patients with pancreatic cystic lesions

BACKGROUND/AIMS

It was recently reported that the quantitative analysis of mutant K-ras gene in pancreatic juice could be useful for the diagnosis of pancreatic cancer. This methodology was applied to patients with pancreatic cystic lesions.

METHODS

DNA was extracted from pancreatic juice collected at the time of endoscopy with injection of secretin. The ratio of the K-ras mutant allele to the wild-type allele was measured by two methods to detect and semiquantify mutant K-ras gene: polymerase chain reaction/preferential homoduplex formation assay and enriched polymerase chain reaction/enzyme linked mini-sequence assay.

RESULTS

A high frequency of K-ras mutation was detected (more than 2% of all K-ras genes) in six of 14 patients (43%) with pancreatic cysts. This frequency was similar to those detected in patients with pancreatic adenocarcinoma and in intraductal papillary neoplasms of the pancreas. In contrast, the frequency of mutation was low (less than 2%) in patients without either pancreatic cysts or pancreatic neoplasms.

CONCLUSIONS

K-ras gene mutation may be derived from duct cells in the pancreas with a high potential for tumorigenesis. Therefore careful follow up of patients with a pancreatic cyst is recommended if they are found to have a high level of the mutant gene in the pancreatic juice.

Molecular cloning and expression of rat antisecretory factor and its intracellular localization

Antisecretory factor (AF) was identified as a pituitary protein that inhibits the intestinal fluid secretion induced by cholera toxin. One aim of this study was to elucidate whether AF is also synthesized in the intestine or if AF produced in the pituitary is transported to the intestinal tract for its function there. cDNA clones encoding a protein proposed to be AF were isolated from rat pituitary gland and intestinal mucosa cDNA libraries. The nucleotide sequences of clones isolated from the rat pituitary gland and intestinal mucosa were identical. The deduced amino acid sequence was highly homologous to the sequence for subunit 5a of the human 26S protease that exists abundantly in the cytosol and nucleus. The production of AF in the intestine was confirmed by Northern blot and immunoblot analyses. Immunocytochemical observations of cells transfected with the rat AF cDNA showed that the AF protein was localized in the cytoplasm. These findings suggest that the protein proposed to be AF may be a cytoplasmic protein, it exists in the intestine rather than being transported from the pituitary gland, and it may function in intestinal cells.

Antibodies against the PH domain of phospholipase C-delta1 inhibit Ins(1,4,5)P3-mediated Ca2+ release from the endoplasmic reticulum

The pleckstrin homology domain (PH domain) is now well known as a structural module for the binding of inositol compounds. In the present study, polyclonal antibodies against the peptide KVKSSSWRRERFYK, derived from the N-terminal of the PH domain of phospholipase C-delta1 (PLC-delta1), were raised in rabbits. These were then tested for their ability to inhibit the binding of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] to the binding proteins including the receptor molecule. The Fab fragment of the antibodies but not the whole molecule inhibited the binding of Ins(1,4,5)P3 not only to PLC-delta1 but also to the Ins(1,4,5)P3 receptor, indicating that the antibodies raised recognized the binding site for Ins(1,4, 5)P3 in the receptor. Rat basophilic leukemic cells were permeabilized with saponin and assayed for Ins(1,4,5)P3-mediated Ca2+ release. Pretreatment of permeabilized RBL cells with the Fab fragment of the antibodies diminished the release of Ca2+ caused by Ins(1,4,5)P3, and further absorption experiments using a variety of synthetic peptides suggested that the tripeptide KVK is the epitope of the antibodies. Structural information about KVK will help in screening for Ins(1,4,5)P3 antagonists.

The peroxin Pex14p. cDNA cloning by functional complementation on a Chinese hamster ovary cell mutant, characterization, and functional analysis

Rat cDNA encoding a 376-amino acid peroxin was isolated by functional complementation of a peroxisome-deficient Chinese hamster ovary cell mutant, ZP110, of complementation group 14 (CG14). The primary sequence showed 28 and 24% amino acid identity with the yeast Pex14p from Hansenula polymorpha and Saccharomyces cerevisiae, respectively; therefore, we termed this cDNA rat PEX14 (RnPEX14). Human and Chinese hamster Pex14p showed 96 and 94% identity to rat Pex14p, except that both Pex14p comprised 377 amino acids. Pex14p was characterized as an integral membrane protein of peroxisomes, exposing its N- and C-terminal parts to the cytosol. Pex14p interacts with both Pex5p and Pex7p, the receptors for peroxisome targeting signal type 1 (PTS1) and PTS2, respectively, together with the receptors' cargoes, PTS1 and PTS2 proteins. Mutation in PEX14 from ZP161, the same CG as ZP110, was determined by reverse transcription-PCR as follows. A 133-base pair deletion at nucleotide residues 37-169 in one allele created a termination codon at 40-42; in addition to this mutation, 103 base pairs were deleted at positions 385-487, resulting in the second termination immediately downstream the second deletion site in the other allele. Neither of these two mutant forms of Pex14p restored peroxisome biogenesis in ZP110 and ZP161, thereby demonstrating PEX14 to be responsible for peroxisome deficiency in CG14.

Elevated plasma levels of glucagon-like peptide-1 after oral glucose ingestion in patients with pancreatic diabetes

OBJECTIVE

The purpose of the present study was to evaluate plasma glucagon-like peptide-1 (GLP-1) responses after oral glucose ingestion in patients with chronic pancreatitis and to clarify how GLP-1 secretion relates to pancreatic diabetes.

METHODS

An oral glucose tolerance test (OGTT) was performed in 17 patients with chronic pancreatitis. Plasma glucose, immunoreactive insulin (IRI), C-peptide, glucagon, and GLP-1 levels at each time point during OGTT were measured. The diagnosis of chronic pancreatitis was made by the findings of endoscopic retrograde pancreatography (ERP): evident dilation of the main pancreatic duct with or without pancreatolithiasis.

RESULTS

The patients were divided into three groups according to the World Health Organization classification of diabetes based on plasma glucose levels after OGTT. The groups were: normal (three patients), impaired glucose tolerant (IGT) (six patients), and diabetic (DM) (eight patients). In the DM group, IRI and C-peptide response levels after oral glucose ingestion were significantly reduced as compared with those of the normal and IGT groups. No significant glucagon responses to oral glucose ingestion were found in the three groups. In contrast, plasma GLP-1 levels were significantly elevated after oral glucose ingestion in the DM groups as compared with normal and IGT groups.

CONCLUSIONS

The present study affords evidence that plasma GLP-1 levels become elevated with development of pancreatic diabetes, although the precise mechanism of this elevation remains undetermined.

Adenovirus mediated p53 tumour suppressor gene therapy for human gastric cancer cells in vitro and in vivo

BACKGROUND/AIMS

Gastric cancer is one of the most prevalent forms of cancer in East Asia. Point mutation of the p53 gene has been reported in more than 60% of cases of gastric cancer and can lead to genetic instability and uncontrolled cell proliferation. The purpose of this investigation was to evaluate the potential of p53 gene therapy for gastric cancer.

METHODS

The responses of human gastric cancer cell lines, MKN1, MKN7, MKN28, MKN45, and TMK-1, to recombinant adenoviruses encoding wild type p53 (AdCAp53) were analysed in vitro. The efficacy of the AdCAp53 treatment for MKN1 and MKN45 subcutaneous tumours in nude mice was assessed in vivo.

RESULTS

p53-specific growth inhibition was observed in vitro in two of four gastric cancer cell lines with mutated p53, but not in the wild type p53 cell line. The mechanism of the killing of gastric cancer cells by AdCAp53 was found, by flow cytometric analysis and detection of DNA fragmentation, to be apoptosis. In vivo studies showed that the growth of subcutaneous tumours of p53 mutant MKN1 cells was significantly inhibited by direct injection of AdCAp53, but no significant growth inhibition was detected in the growth of p53 wild type MKN45 tumours.

CONCLUSIONS

Adenovirus mediated reintroduction of wild type p53 is a potential clinical utility in gene therapy for gastric cancers.

Washout of small stones in the bile duct by saline infusion using a side-holed balloon catheter in patients undergoing endoscopic papillary balloon dilation

BACKGROUND

Complete bile duct clearance of stones should be achieved in patients managed with endoscopic papillary balloon dilation. However, complete retrieval of small stones or tiny fragments sometimes proves difficult using conventional devices.

METHODS

We attempted the removal of fine stone fragments by saline infusion using a specially designed retrieval balloon catheter with a blind tip and a side hole located proximal to the balloon in 14 patients.

RESULTS

Using this technique, bile duct clearance was achieved in a single attempt in 13 of 14 patients; 2 attempts were required in 1 patient. Cholecystitis occurred in 2 patients with gallstones in situ after the procedure.

CONCLUSIONS

Saline washout using a side-holed retrieval balloon catheter effectively cleans stones and stone fragments from the bile duct in patients treated with endoscopic papillary balloon dilation.

Atropine-resistant secretion of a putative luminal CCK-releasing peptide in conscious rats

The changes in levels of the newly discovered luminal CCK-releasing factor (LCRF) in the small intestinal lumen before and after bile-pancreatic juice diversion in conscious rats were examined by a specific RIA. Moreover, we also examined whether LCRF secretion was under cholinergic control. Anti-LCRF antiserum was raised in rabbits, and a sensitive RIA was established. The localization of LCRF was examined by immunohistochemistry. The luminal content of LCRF was significantly increased by bile-pancreatic juice diversion, during which luminal trypsin activity was eliminated. The increase in luminal LCRF content was not inhibited by intravenous infusion of atropine. The changes in plasma levels of CCK and pancreatic secretion were similar to those in luminal LCRF contents. LCRF immunostaining was observed in villus tip enterocytes of the small intestine and was most prominent in the duodenal portion. These results support our original hypothesis that LCRF may be released spontaneously into the small intestinal lumen from the villus tip enterocytes and its intraluminal degradation by proteases regulates CCK release. Furthermore, LCRF release was not subject to cholinergic regulation.

Adenovirus-mediated transduction of Escherichia coli uracil phosphoribosyltransferase gene sensitizes cancer cells to low concentrations of 5-fluorouracil

5-fluorouracil (5-FU), although a widely used chemotherapeutic agent, has a limited effect in the treatment of human solid tumors due to their resistance to the cytotoxic effects of 5-FU. Escherichia coli uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage enzyme that catalyzes the synthesis of UMP from uracil and 5-phosphoribosyl-alpha-1-diphosphate. The present study demonstrates that adenovirus-mediated transduction of E. coli UPRT gene results in marked sensitization of colon, gastric, liver, and pancreas cancer cell lines to low concentration of 5-FU in vitro. The in vitro bystander effect was observed when only 10% of the hepatoma Hep3B cells were infected with UPRT-expressing adenovirus. In addition, 5-FU treatment of human hepatoma or gastric cancer xenografts in nude mice transduced with UPRT was demonstrated to result in significant in vivo antitumor effects. The adenovirus vector transduction of the UPRT gene followed by 5-FU administration is representative of a new chemosensitization strategy for cancer gene therapy.

Jun and MAP kinases are activated by cholecystokinin in the pancreatic carcinoma cell line KP-1N

Growth of the human pancreatic carcinoma cell line KP-1N was stimulated with cholecystokinin (CCK)-8. A 40% increase in cell numbers was observed in the presence of 10(-10) MCCK-8 and this increase was inhibited by the addition of 25 microM CCK-A receptor antagonist (CR1505). The binding affinity of CCK-8 to KP-1N cells was 21-fold higher than that of gastrin 17-I. No significant increase in intracellular Ca2+ concentration was found upon stimulation with CCK-8. Components of signal transduction pathways that were activated in KP-1N cells after stimulation with CCK-8 were studied. CCK-8 stimulated tyrosine phosphorylation of a mitogen-activated protein kinase (MAPK) of approximately 42 kDa (p42map). c-Jun amino-terminal kinases (JNKs) of 46 kDa (p46jnk) and 55 kDa (p55jnk) were also activated by CCK-8 and increased the phosphorylation of c-Jun. CCK-8 at 10(-7) M induced 1.5-fold increases in the phosphorylation of MAPK and of c-Jun by JNKs, respectively. These results suggest that cell proliferation stimulated with CCK-8 in KP-1N cells may be mediated by signal transduction cascades leading to activation of JNKs and MAPKs.

Role of cholecystokinin-A (CCK-A) receptor in pancreatic regeneration after pancreatic duct occlusion: a study in rats lacking CCK-A receptor gene expression

We examined the role of the cholecystokinin-A (CCK-A) receptor in acute inflammatory and regenerative stages of experimental pancreatitis using a rat model lacking the CCK-A receptor [Otsuka Long-Evans Tokushima Fatty (OLETF) rats]. OLETF and control [Long-Evans Tokushima Otsuka (LETO)] rats were prepared with an internal bile fistula and with obstruction of pancreatic flow and were sacrificed 1-14 days later. Histological examination was performed, and changes in pancreatic wet weight, protein concentration, CCK-A and -B receptor mRNA levels, tyrosine kinase activities, and plasma amylase and CCK levels were determined. The plasma amylase level showed a transient increase on day 1, the CCK level remained at high levels throughout, and tyrosine kinase activity was increased significantly on day 3 but declined thereafter. These parameters were comparable for both strains during the acute inflammatory stage. However, no regenerative findings were observed by histological examination and the protein concentration in the pancreas was significantly lower in OLETF rats on days 7-14, during which time regeneration was completed in LETO rats. These observations indicate that the absence of the CCK-A receptor did not modify the acute phase of pancreatitis but significantly retarded regeneration of the pancreatic tissue.

Peroxisome biogenesis disorders: identification of a new complementation group distinct from peroxisome-deficient CHO mutants and not complemented by human PEX 13

Ten complementation groups of generalized peroxisome biogenesis disorders (PBD), (excluding rhizomelic chondrodysplasia punctata) have been identified using complementation analysis. Four of the genes involved have been identified using two different methods of (1) genetic functional complementation of peroxisome deficient CHO cell mutants and (2) homology searches for human dbEST, based on yeast genes involved in peroxisome biogenesis (PEX genes). We report here the first identification of a new complementation group which is genetically different from peroxisome deficient CHO mutants. There were no complementations by the human PEX 13 gene. The nature of the related gene is being investigated.

Endoscopic papillary balloon dilation for the management of common bile duct stones: experience of 226 cases

BACKGROUND AND STUDY AIMS

Endoscopic sphincterotomy is a widely accepted technique for the treatment of patients with common bile duct stones. However, it is still associated with occasional complications. The recently developed technique of endoscopic papillary balloon dilation seems to be a safe and effective procedure, and to have great potential for replacing endoscopic sphincterotomy. However, few reports have been published on the use of this technique for bile duct stones. The present study was undertaken to evaluate its safety and efficacy.

PATIENTS AND METHODS

Endoscopic papillary balloon dilation was used to remove common bile duct stones in 226 consecutive patients including 41 patients of ASA classification III/IV, 41 elderly patients (> 80 years) 24 with liver cirrhosis, and 86 with periampullary diverticulum. After dilation of the papilla with a balloon diameter of 8 mm, the stones were retrieved.

RESULTS

In conjunction with the use of a mechanical or/and electrohydraulic lithotriptor in 79 patients (35%) with large stones (> 10 mm in diameter), clearance of the common bile duct was achieved in 225 of 226 patients (99%) without serious complications, such as hemorrhage or severe pancreatitis; mild (n = 13) or moderate (n = 2) pancreatitis occurred in 7% of cases.

CONCLUSIONS

Endoscopic papillary balloon dilation is a safe and effective technique for the treatment of common bile duct stones, even in high-risk patients.

Peroxisome targeting signal type 1 (PTS1) receptor is involved in import of both PTS1 and PTS2: studies with PEX5-defective CHO cell mutants

To investigate the mechanisms of peroxisome assembly and the molecular basis of peroxisome assembly disorders, we isolated and characterized a peroxisome-deficient CHO cell mutant, ZP139, which was found to belong to human complementation group II, the same group as that of our earlier mutant, ZP105. These mutants had a phenotypic deficiency in the import of peroxisomal targeting signal type 1 (PTS1) proteins. Amino-terminal extension signal (PTS2)-mediated transport, including that of 3-ketoacyl coenzyme A thiolase, was also defective in ZP105 but not in ZP139. PEX5 cDNA, encoding the PTS1 receptor (PTS1R), was isolated from wild-type CHO-K1 cells. PTS1R's deduced primary sequence comprised 595 amino acids, 7 amino acids less than the human homolog, and contained seven tetratricopeptide repeat (TPR) motifs at the C-terminal region. Chinese hamster PTS1R showed 94, 28, and 24% amino acid identity with PTS1Rs from humans, Pichia pastoris, and Saccharomyces cerevisiae, respectively. A PTS1R isoform (PTS1RL) with 632 amino acid residues was identified in CHO cells; for PTS1R, 37 amino acids were inserted between residues at positions 215 and 216 of a shorter isoform (PTS1RS). Southern blot analysis of CHO cell genomic DNA suggested that these two isoforms are derived from a single gene. Both types of PEX5 complemented impaired import of PTS1 in mutants ZP105 and ZP139. PTS2 import in ZP105 was rescued only by PTS1RL. This finding strongly suggests that PTS1RL is also involved in the transport of PTS2. Mutations in PEX5 were determined by reverse transcription-PCR: a G-to-A transition resulted in one amino acid substitution: Gly298Glu of PTS1RS (G335E of PTS1RL) in ZP105 and Gly485Glu of PTS1RS (G522E of PTS1RL) in ZP139. Both mutations were in the TPR domains (TPR1 and TPR6), suggesting the functional consequence of these domains in protein translocation. The implications of these mutations are discussed.

Serum levels of eosinophil cationic protein and IL-5 in patients with asthma without systemic corticosteroids

We measured the serum levels of eosinophil cationic protein (ECP) and interleukin-5 (IL-5) in 39 patients with asthma (symptomatic 12, asymtomatic 27) without systemic corticosteroids and 49 healthy subjects. There were significant differences in serum levels in both ECP and IL-5 between symptomatic and asymptomatic asthma, and healthy subjects. A significant positive correlation was found between serum levels of ECP and IL-5. No significant correlation was found between %FEV1 and serum level of ECP or IL-5, however, when the analysis was restricted to patients of less than 60 years of age, the correlations were significant. These results suggest that IL-5 is one of the factors that activate eosinophils even in peripheral blood, and that measurement of serum levels of ECP and IL-5 is useful for in vitro monitoring of asthma.

Newly identified Chinese hamster ovary cell mutants defective in peroxisome biogenesis represent two novel complementation groups in mammals

We isolated peroxisome biogenesis mutants from Chinese hamster ovary (CHO) cells, using the 9-(1'-pyrene)nonanol/ultraviolet (P9OH/ UV) method and wild-type CHO-K1 cells that had been stably transfected with cDNA encoding Pex2p (formerly peroxisome assembly factor-1, PAF-1). Three mutant cell clones, ZP110, ZP111, and ZP114, showed cytosolic localization of catalase, thereby indicating a defect in peroxisome biogenesis, whereas ZP112 and ZP113 contained fewer but larger catalase-positive particles. Mutant ZP115 displayed an aberrant, tubular structure immunoreactive to anti-catalase antibody. Mutants lacking morphologically recognizable peroxisomes also showed the typical peroxisome assembly-defective phenotype such as severe loss of catalase latency and resistance to 12-(1'-pyrene)dodecanoic acid (P12)/UV treatment. ZP110 and ZP111, and ZP114 were found to belong to two novel complementation groups, respectively, by complementation group analysis with cDNA transfection and cell fusion. Cell fusion with fibroblasts from patients with peroxisome biogenesis disorders such as Zellweger syndrome revealed that ZP110 and ZP114 could not be classified to any of human complementation groups. Thus, ZP110/ZP111 and ZP114 are the first, two peroxisome-deficient cell mutants of newly identified complementation groups distinct from the ten mammalian groups previously characterized.

Extrapancreatic action of truncated glucagon-like peptide-I in Otsuka Long-Evans Tokushima Fatty rats, an animal model for non-insulin-dependent diabetes mellitus

To clarify the mechanism(s) of the antidiabetic effects of truncated glucagon-like peptide-1 (GLP-1) in diabetics, we examined its insulinotropic and extrapancreatic effects in a newly established strain of spontaneously non-insulin-dependent diabetic (NIDDM) rats, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, that received a continuous infusion of truncated GLP-1 620 pmol/d/kg (G group, n = 12) or of vehicle (V group, n = 12) for 4 weeks by Alzet pump. Nonfasting plasma glucose levels were significantly lower (P < .05) in the G group than in the V group (7.0 +/- 0.67 v 9.1 +/- 1.7 mmol/L), and fasting plasma immunoreactive insulin (IRI) levels were lower in the former than in the latter (0.63 +/- 0.31 v 0.78 +/- 0.25 nmol/L). At day 15 of infusion, the G group showed an attenuated plasma glucose response to an oral glucose load, but had plasma IRI levels comparable to those in the V group. A long-term infusion of truncated GLP-1 increased the glucose infusion rate (GIR) significantly (P < .05) during a euglycemic-hyperinsulinemic clamp test (59.0 +/- 14.8 mumol/kg/min for group G v 38.9 +/- 12.2 for group V), but hepatic glucose output (HGO) did not differ significantly for either group. Uptake of 2-deoxy-D-glucose (2DG) by peripheral muscles in the G group was as much as 2.4-fold higher than in the V group (5.52 +/- 2.04 v 2.29 +/- 0.97 mumol/100 g muscle weight/min). We conclude from these data that truncated GLP-1, in addition to its well-known incretin effect, is capable of augmenting insulin action in peripheral tissues of diabetics, which can contribute, in part, to improve glucose intolerance in OLETF rats.