Mediation of humoral catecholamine secretion by the renin-angiotensin system in hypotensive rainbow trout (Oncorhynchus mykiss)

The individual contributions of, and potential interactions between, the renin-angiotensin system (RAS) and the humoral adrenergic stress response to blood pressure regulation were examined in rainbow trout. Intravenous injection of the smooth muscle relaxant, papaverine (10 mg/kg), elicited a transient decrease in dorsal aortic blood pressure (PDA) and systemic vascular resistance (RS), and significant increases in plasma angiotensin II (Ang II) and catecholamine concentrations. Blockade of alpha-adrenoceptors before papaverine treatment prevented PDA and RS recovery, had no effect on the increase in plasma catecholamines, and resulted in greater plasma Ang II concentrations. Administration of the angiotensin-converting enzyme inhibitor, lisinopril (10(-4) mol/kg), before papaverine treatment attenuated the increases in the plasma concentrations of Ang II, adrenaline, and noradrenaline by 90, 79, and 40%, respectively and also prevented PDA and RS recovery. By itself, lisinopril treatment caused a gradual and sustained decrease in PDA and RS, and reductions in basal plasma Ang II and adrenaline concentrations. Bolus injection of a catecholamine cocktail (4 nmol/kg noradrenaline plus 40 nmol/kg adrenaline) in the lisinopril+papaverine-treated trout, to supplement their circulating catecholamine concentrations and mimic those observed in fish treated only with papaverine, resulted in a temporary recovery in PDA and RS. These results indicate that the RAS and the acute humoral adrenergic response are both recruited during an acute hypotensive stress, and have important roles in the compensatory response to hypotension in rainbow trout. However, whereas the contribution of the RAS to PDA recovery is largely indirect and relies on an Ang II-mediated secretion of catecholamines, the contribution from the adrenergic system is direct and relies at least in part on plasma catecholamines.

[Attenuation of reperfusion phenomenon by reperfusion using leukocyte-depleted blood during direct percutaneous transluminal coronary angioplasty for acute myocardial infarction]

Leukocytes are important in the occurrence of reperfusion injury in coronary intervention for acute myocardial infarction (AMI). This study compared reperfusion injury caused by reperfusion using leukocyte-depleted blood (LD) and that by conventional angioplasty (control) through the reperfusion phenomenon including reperfusion arrhythmia and additional ST elevation during direct percutaneous transluminal coronary angioplasty (PTCA) in 41 patients with 21 left anterior descending artery (LAD) lesions and 20 right coronary artery (RCA) lesions. LD was prepared from 20 ml of venous blood, 20 ml of mixed blood and 60 ml of arterial blood from the patients (LD group; LAD-LD: n = 10, RCA-LD: n = 10) which was passed through a leukocyte removal filter. The blood was injected from the tip of the balloon catheter at 10 ml/min during inflation for 10 min before balloon deflation. The control group (LAD-control: n = 11, RCA-control: n = 10) underwent conventional angioplasty. The appearance of reperfusion arrhythmia [atrioventricular block (AVB) > II, accelerated idioventricular rhythm (AIVR), ventricular tachycardia (VT), ventricular fibrillation (Vf)] and measurements of STmax deviation before and after reperfusion, the differences of the STmax deviation (delta ST) and additional ST elevation (LAD: > or = 0.5 mV increase of sigma ST in lead V1-V6, RCA: > or = 0.3 mV increase of sigma ST in lead II, III and aVF) were studied. The appearance of reperfusion arrhythmias was as follows; LAD-LD: AVB 0, AIVR 1, VT 1, Vf 0, LAD-control: AVB 0, AIVR 4, VT 2, Vf 1, NS, and RCA-LD: AVB 0, AIVR 0, VT 0, Vf 0, RCA-control: AVB 2, AIVR 0, VT 1, Vf 0, NS. There was no reperfusion arrhythmia in the RCA-LD group. There was no significant difference in the appearance of reperfusion arrhythmias between the LAD-LD and LAD-control or RCA-LD and RCA-control groups. Before reperfusion the STmax deviation (mV) was LAD-LD 0.86 +/- 0.46 vs LAD-control 0.74 +/- 0.49 and RCA-LD 0.29 +/- 0.18 vs RCA-control 0.15 +/- 0.09 and after reperfusion LAD-LD 0.63 +/- 0.35 vs LAD-control 0.81 +/- 0.49 and RCA-LD 0.13 +/- 0.15 vs RCA-control 0.20 +/- 0.12, respectively. There were no significant differences between LAD-LD and LAD-control or RCA-LD and RCA-control groups. delta ST (mV) was LAD-LD 0.23 +/- 0.56 vs LAD-control 0.07 +/- 0.60, p = 0.09 and RCA-LD 0.16 +/- 0.12 vs RCA-control 0.06 +/- 0.14, p = 0.002, respectively. The number of patients with additional ST elevation soon after reperfusion was LAD-LD 3 vs LAD-control 10, p < 0.05 and RCA-LD 0 vs RCA-control 8, p < 0.001, respectively.

Molecular cloning of CLC chloride channels in Oreochromis mossambicus and their functional complementation of yeast CLC gene mutant

We have cloned two members of the CLC chloride channel family (OmCLC-3 and OmCLC-5) from gill cDNA libraries of the euryhaline tilapia Oreochromis mosammbicus. At the amino acid level, OmCLC-3 is 90.5% identical to rat CLC-3 and OmCLC-5 is 79.2% identical to rat CLC-5. Ribonuclease protection assay revealed that OmCLC-5 was mainly expressed in the gill, kidney, and intestine in both freshwater- (FW) and seawater- (SW) adapted tilapia. Although the mRNA of OmCLC-3 was broadly expressed in tissues of FW- and SW-adapted tilapia, the most intense signals were observed in the gill, kidney, intestine, and brain. Injection of OmCLC-3 and OmCLC-5 cRNAs into Xenopus oocytes did not elicit chloride currents, but these clones did functionally complement the gef1 phenotype of YPH250(gef), a yeast strain in which a single CLC channel (GEF1) has been disrupted by homologous recombination. These results clearly indicated that CLC channels closely related to the mammalian CLC-3, -4, and -5 subfamily exist also in tilapia and that OmCLC-3 and OmCLC-5 function as intracellular chloride channels.

Association of ulcerative colitis with rare VNTR alleles of the human intestinal mucin gene, MUC3

Ulcerative colitis (UC), a common form of inflammatory bowel disease, is a multifactorial disorder with significant genetic influence. Recently, evidence of linkage on chromosome 7q near the intestinal mucin gene MUC3 was reported by an affected sib-pair analysis. Previous reports indicate a possible mucin abnormality in UC patients, but whether genetic differences in a specific mucin gene are associated with UC is unknown. Here we analysed polymorphisms of variable number of tandem repeats (VNTRs) within this gene using DNAs obtained from 243 Japanese (75 patients with UC and 168 controls), and to confirm the result we undertook a two-stage examination using 328 Caucasian samples (72 and 85 with UC in the first and second stages, respectively, and 171 controls). When the frequency of patients carrying one or two rare VNTR alleles was compared with that of controls, a significant increase was found first in Japanese patients (odds ratio 2.72, 95% CI 1.17-6.32, P = 0. 0308). In Caucasians, the odds ratio was 2.80 (95% CI 1.36-5.75, P = 0.0079) in the first stage, 2.43 (95% CI 1.20-4.92, P = 0.0196) in the second stage and 2.60 (95% CI 1.41-4.80, P = 0.0024) in total. The overall odds ratio was 2.64 (95% CI 1.60-4.33, P = 0.0001). This result suggests that rare alleles of the MUC3 gene may confer genetic predisposition to UC.

Cloning, properties and tissue distribution of natriuretic peptide receptor-A of euryhaline eel, Anguilla japonica

During the course of cloning and characterization of natriuretic peptide receptor-A (NPR-A) from the euryhaline fish eel, Anguilla japonica, we identified a splice variant with unique structural properties that affect ligand-inducible intrinsic guanylate cyclase activity. The variant, generated from a splice between a cryptic donor site and the normal acceptor site, lacked nine amino acid residues (VFTKTGYYK) in the kinase-like regulatory domain. This deletion of a very short segment resulted in the complete loss of the ligand inducibility of the cyclase activity. The nine-amino acid segment may therefore be useful as a target for studies aimed at clarifying the mechanism of activation of the guanylate cyclase domain. Characterization of the normal form of eel NPR-A also led to the following interesting findings. Although eel NPR-A had a domain structure very similar to that of mammalian counterparts, it lacked the third cysteine residue in the extracellular domain which is conserved among mammalian NPR-A molecules. The eel receptor bound both amidated and nonamidated eel atrial natriuretic peptide (eANP) with high affinity but, when assayed for ligand-inducible cGMP generation, it responded efficiently only to physiological concentrations of the amidated ligand, suggesting that the biologically active form is the amidated eANP, and the nonamidated form acts as a partial antagonist; similarly, nonhomologous rat ligands behaved like antagonists toward the eel receptor in the concentration range 0.1-10 nm. The receptor message was found to be relatively abundant in the osmoregulatory organs such as the gill, kidney, intestine and urinary bladder.

Awareness of and attitude of elderly subjects regarding health care and welfare in rapidly ageing population in Japan

OBJECTIVES

We aimed to obtain information on the degree of knowledge and understanding about the current systems of health care and welfare held by the elderly, in order to achieve comprehensiveness in family practice.

METHOD

We conducted a study on the awareness of healthy elderly persons by direct interview. The study was carried out in Kuni Village in a remote mountainous region in Japan, where the elderly population accounts for 24.8% of the total population. The subjects were self-dependent in their daily living activities and were aged 65 years and older.

RESULTS

The subjects' knowledge of health care and welfare systems was generally good, and the degree of their utilization of these systems was also good. But 83.3% of those who did not want to utilize the welfare system indicated their preference to depend on their family for support.

CONCLUSION

Family physicians must endeavour to offer comprehensive care to their patients by including these systems for rapidly ageing communities.

Effects of homologous atrial natriuretic peptide on drinking and plasma ANG II level in eels

The effects of eel atrial natriuretic peptide (ANP) on drinking were investigated in eels adapted to freshwater (FW) or seawater (SW) or in FW eels whose drinking was stimulated by a 2-ml hemorrhage. An intra-arterial infusion of ANP (0.3-3.0 pmol . kg-1 . min-1), which increased plasma ANP level 1.5- to 20-fold, inhibited drinking dose dependently in all groups of eels. The drinking rate recovered to the level before ANP infusion within 2 h after infusate was replaced by saline. The inhibition at 3.0 pmol . kg-1 . min-1 was profound in FW eels and hemorrhaged FW eels, whereas significant drinking still remained after inhibition in SW eels. Plasma ANG II concentration also decreased dose dependently during ANP infusion and recovered to the initial level after saline infusion in all groups of eels. The decrease at 3.0 pmol . kg-1 . min-1 was large in FW eels and hemorrhaged FW eels compared with that of SW eels. Thus the changes in drinking rate and plasma ANG II level were parallel during ANP infusion. Plasma sodium concentration and osmolality decreased during ANP infusion in SW and FW eels, and they were restored after saline infusion. In hemorrhaged FW eels, however, ANP infusion did not alter plasma sodium concentration and osmolality. Hematocrit did not change during ANP infusion in any group of eels. Collectively, ANP infusion at physiological doses decreased drinking rate and plasma ANG II concentration in parallel in both FW and SW eels. It remains undetermined whether the inhibition of drinking is caused by direct action of ANP or through inhibition of ANG II, which is known as a potent dipsogen in all vertebrate species, including eels.

Event-related potentials in patients with obsessive-compulsive disorder

Twenty-three unmedicated patients with obsessive-compulsive disorder (OCD) were compared with 12 unmedicated patients with social phobia (SP) and 18 age-matched normal controls (C) using a two-tone auditory oddball event-related potentials (ERP) paradigm. The OCD group showed significantly shorter P300 latencies and shorter N200 latencies for target stimuli than the SP and the C groups. The OCD patients also tended to have greater N200 negativity compared with normal controls. However, there were no significant relationships between these ERP abnormalities in OCD patients and the type or severity of their OCD symptoms. In the mean ERP waveforms, increased N200 negativity for target stimuli, as well as the provocation in the later part of N200 for non-target stimuli, were more commonly observed in the OCD and the SP groups compared with the C group. These results raise the possibility that the shorter N200 and P300 latencies in OCD patients may be an OCD-specific phenomenon that is more closely related to the biological basis for OCD, rather than the characteristics of their OCD symptoms. On the other hand, increased negativity in the N200 region, even for non-target stimuli, may represent the common abnormalities among anxiety disorders.

A novel hepatic stellate (Ito) cell-derived protein, epimorphin, plays a key role in the late stages of liver regeneration

Limited data exist regarding morphogenesis and differentiation during liver regeneration. We examined the role of epimorphin on liver regeneration. After 70% partial hepatectomy, mouse liver was collected on days 1, 3, 7, and 14 for immunohistochemistry and the detection of epimorphin mRNA and connexin 32. Using primary cultured rat hepatocytes, morphogenesis and differentiation of cells were tested with or without epimorphin. Seven days after cell inoculation, the expression of connexin 32 and the cell-cell communication was tested as a marker of differentiation. Epimorphin was detected exclusively in hepatic stellate cells. Connexin 32 was detected only in hepatocytes. After partial hepatectomy, epimorphin mRNA was detected on day 3 and peaked at day 7, followed by protein expression. Connexin 32 expression showed a similar time course. Cultured hepatocytes formed multicellular spheroids in an active epimorphin-coated culture dish and showed positive dye coupling, whereas the cell-cell communication was lost without active epimorphin. Because epimorphin was expressed late in liver regeneration, it might play a role in morphogenesis and differentiation.

A radioimmunoassay for the determination of angiotensin II in elasmobranch fish

A homologous radioimmunoassay was developed to determine the concentration of angiotensin II (Asn1, Pro3, Ile5)-Ang II) in elasmobranchs. Cross-reactivity with elasmobranch angiotensin I and other heterologous angiotensins was high and therefore all potentially cross-reacting angiotensins were separated by high performance liquid chromatography after prior extraction with Sep-Pak C18 cartridges. The validity of the assay for the determination of elasmobranch Ang II was demonstrated by parallelism with a series of Ang II standards with serially diluted elasmobranch plasma extracts. Overall recovery of elasmobranch Ang II added to a plasma pool was 75.1 +/- 5.2%. Plasma Ang II concentrations measured by our RIA were similar in fish adapted to 70, 100, or 120% SW at 139 +/- 20.1, 109 +/- 15.3, and 119 +/- 16.3 fmol . ml-1, respectively.

Direct vasoconstrictor action of homologous angiotensin II on isolated arterial ring preparations in an elasmobranch fish

Arterial rings were prepared from the branchial artery, coeliac artery and ventral aorta of the Japanese dogfish Triakis scyllia and used to determine arterial contraction in a myograph. Noradrenaline caused a dose-dependent contraction (10(-9)-3 x 10(-6) M) that was completely inhibited by pre-treatment with 10(-7) M phentolamine. Homologous dogfish angiotensin II (ANG II) ([Asn1, Pro3, Ile5]-ANG II) also caused dose-dependent contraction (10(-9)-3 x 10(-6) M), but phentolamine had no effect on this response. Administration of dogfish angiotensin I (ANG-I) ([Asn1, Pro3, Ile5, Gln9]-ANG I) resulted in a contraction similar to that produced by ANG II and the effect could be blocked with 10(-7) M captopril. The mammalian ANG II receptor antagonists [Sar1, Ile8]-ANG II and [Sar1, Ala8]-ANG II caused dose-dependent contractions of coeliac artery rings, but were less potent than homologous ANG I and ANG II. These results show that the contractile effect of [Asn1, Pro3, Ile5]-ANG II is not mediated by the alpha-adrenergic system and contractions of arterial rings by noradrenaline and elasmobranch ANG II are mediated by separate vascular receptors. The elasmobranch ANG II vascular receptor may have co-evolved with the unusual structure of this peptide.

Isolation of a novel TP53 target gene from a colon cancer cell line carrying a highly regulated wild-type TP53 expression system

We established a colon cancer cell line SW480-LOWTP53-1 carrying a wild-type TP53 transgene that is inducible under control of the lactose operon. Induction of this transgene by isopropyl-beta-D-thiogalactoside (IPTG) arrests growth of the transfected cells. To investigate cellular responses related to the TP53 signaling pathway to induce growth arrest, we applied a differential display method to screen mRNAs isolated from this cell line and looked for genes whose expression was activated or suppressed after induction of wild-type TP53. Subsequent Northern blot analysis confirmed that expression of one novel gene was regulated by wild-type TP53. The cDNA, termed TP53TG1 (TP53 target gene 1), contained an open reading frame of 270 nucleotides encoding 90 amino acids. Under conditions of cellular stress (ultraviolet irradiation or exposure to bleomycin or cisplatin), expression of TP53TG1 was induced in a wild-type TP53-dependent manner, indicating that this gene is likely to play an important role in the signaling pathway of TP53 and may function in response to cellular damage.

Identification of a novel MCM3-associated protein that facilitates MCM3 nuclear localization

MCM3 is essential for the initiation of DNA replication and also participates in controls that ensure DNA replication is initiated once per cell cycle. In a two-hybrid screen for proteins that interact with human MCM3, we identified and cloned a novel protein of which the calculated molecular weight is 80,291. A specific antibody against the protein identified a 80-kDa protein in HeLa cell extract, indicating the protein actually expressed in cells. The interaction of these proteins was confirmed by immunoprecipitation assay. Moreover, we clarified a nuclear localization signal of human MCM3, and we find that mutagenesis on the nuclear localization signal of MCM3 affected the binding of newly isolated MCM3-assosiated protein, Map80. Map80 was expressed in Escherichia coli as a fusion with His6 tag and purified with sequential column chromatographies. The addition of recombinant Map80 stimulated the amount of nuclear localized MCM3. These results suggest that Map80 is involved in the nuclear localization pathway of MCM3.

Personality disorders in patients with obsessive-compulsive disorder in Japan

A total of 75 patients with obsessive-compulsive disorder (OCD) were studied in order to investigate the characteristics of OCD symptoms and the comorbidity of personality disorders (PD). Contamination obsessions and checking compulsions were most commonly found in patients, of whom 53% met the criteria for at least one PD. Among comorbid PD, the anxious-fearful (cluster C) PDs, such as avoidant, obsessive-compulsive and dependent PD, were most prevalent, followed by the odd-eccentric (cluster A) PDs, such as paranoid and schizotypal PD. The patients with PD had more severe social maladaptation and concurrent depressive and anxious symptoms than the patients without any PD, despite the similar severity of OCD symptoms. These results are consistent with those reported in the Western world, and are considered to be relatively stable cross-culturally.

Usefulness of nested PCR and sequence analysis in a nosocomial outbreak of neonatal enterovirus infection

BACKGROUND

Non-polio enterovirus infections are recognized in children during summer-fall seasons and they sometimes cause large outbreaks. We experienced a nosocomial infection in the neonatal nursery and echovirus type 7 was isolated from samples of four patients.

OBJECTIVES

We diagnosed the horizontal infection of four neonates by reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) and the nucleotide sequence.

STUDY DESIGN

Total RNA was extracted from clinical isolates, serum samples and cerebrospinal fluid (CSF). We amplified enterovirus genome in the 5'-noncoding region by nested PCR and determined the nucleotide sequences.

RESULTS

Enterovirus genome was detected in all isolates, in the acute-phase sera in all four patients and in the CSF in one patient by the first PCR. By using nested PCR, the genome was detected from convalescent-phase sera in two patients. All enterovirus genome obtained from the nursery outbreak showed the same sequences with 100% homology.

CONCLUSION

We demonstrated the clinical advantages of RT-nested PCR from serum samples and the analysis of nucleotide sequencing gave the supportive evidence of identification of transmission pathway.

Synthesis of novel polyampholyte comb-type copolymers consisting of a poly(L-lysine) backbone and hyaluronic acid side chains for a DNA carrier

The polyampholyte comb-type copolymers consisting of a poly(L-lysine) (PLL) main chain, a DNA binding site, and hyaluronic acid (HA) side chains, cell-specific ligands, have been prepared as the DNA carrier targeting sinusoidal endothelial cells of liver. The reducing end of HA and epsilon-amino groups of PLL were covalently coupled by reductive amination to obtain the resulting comb-type copolymers (PLL-graft-HA). The chain length of HA was controlled by the enzymatic hydrolysis of high-molecular weight HA. Since HA formed polyion complexes with PLL, the coupling reaction was carried out with high-ionic strength media to suppress polyion complex formation. The reaction proceeded in a homogeneous system, leading to a high efficiency of coupling (>70%) of HA onto the PLL backbone. By using the enzymatic hydrolysis of HA and the reductive amination reaction between HA and PLL with high-ionic strength media, it is possible to prepare the various comb-type copolymers with a defined density and a defined length of HA side chains. Furthermore, we also find that these polyampholyte comb-type copolymers vary their assembling structure in water in response to two kinds of environmental factors, i.e., ionic strength and pH. Finally, a 1H NMR study reveals that the PLL backbone efficiently interacts with DNA molecules despite the presence of HA side chains having negative charges.

beta-Glucosidase activity in the rat small intestine toward quercetin monoglucosides

In order to evaluate the positional specificity for a glucoside group in the hydrolysis of flavonoid glucosides in the rat small intestine, beta-glucosidase activity was measured with the quercetin monoglucosides, quercetin-3-O-beta-D-glucopyranoside (Q3G), quercetin-4'-O-beta-D-glucopyranoside (Q4'G) and quercetin-7-O-beta-D-glucopyranoside (Q7G), as well as with quercetin-3-O-rutinoside (rutin) and p-nitrophenyl-beta-D-glucopyranoside (NPG) by using the HPLC technique. Enzymes were prepared from rat small intestinal mucosa of the duodenum, jejunum and ileum, among which the enzyme activity of the jejunum was highest for all the glycosides tested. Q4'G was the richest substrate for a beta-glucosidase solution among these glycosides, while rutin and NPG were both poor substrates. This suggests that dietary flavonoid glucosides are primarily hydrolyzed and liberated aglycones in the jejunum.

A selective transthyretin-adsorption column for the treatment of patients with familial amyloid polyneuropathy

A transthyretin (TTR)-adsorption column has been developed for the removal of variant TTR from the plasma of patients with familial amyloid polyneuropathy (FAP). The adsorbent is an ion-exchange resin made of porous beads of polyvinyl alcohol gel covalently bound with dimethylaminoethanol. This column was used for three patients with type I FAP. It reduced the concentrations of both normal and variant TTR in the plasma to about half of their pre-adsorption levels. Except for thyroxine, retinol-binding protein and IgM, other proteins in serum were not significantly decreased and there were no adverse effects in long term clinical usage of this TTR-adsorption column. In this trial, we did not obtain concrete evidence that TTR-adsorption therapy can stop or delay the progression of the disease in a FAP patient. However, if we are able to apply this technique more frequently and effectively, TTR-adsorption therapy using our column might be useful for the treatment of FAP patients.

Role of daunorubicin in the induction therapy for adult acute myeloid leukemia

PURPOSE

To evaluate the relationship of total-dose of daunorubicin (DNR) to the induction therapy and treatment outcome, we have administered individualized doses of DNR during induction treatment to patients with acute myelogenous leukemia (AML).

PATIENTS AND METHODS

Ninety-two previously untreated adult patients with AML who entered our hospital were analyzed for the dose of DNR required to achieve complete remission (CR), the CR rate, disease-free survival (DFS), and overall survival (OS). Induction therapy consisted of DNR 40 mg/m2 daily intravenously from day 1 until the marrow was hypoplastic, cytarabine (Ara-C), prednisolone (PRD), and/or 6-thioguanine (6-TG).

RESULTS

Eighty-three of 92 patients with adult AML were assessable for this study. Sixty-three (76%) patients achieved CR. Fifty-two of 63 CR patients achieved the CR in the first course of induction therapy, and 11 patients required the second course of induction therapy. The 5-year and 10-year DFS rates were 31.2% and 5-year and 10-year OS rates were 45.1% and 42.3%, respectively. The median total dose of DNR in the induction therapy was 280 mg/m2 (120 to 480 mg/m2). DNR dose did not influence the response to therapy and was not influenced by the initial WBC count or French-American-British (FAB) system classification.

CONCLUSION

These results indicated that when the dose was linked to observed tumor response, the optimal dose of DNR in the induction therapy was approximately 280 mg/m2 (40 mg/m2 for 7 days), which is greater than the conventional dose of 40 to 60 mg/m2 for 3 days.

Cyclooxygenase-2 inhibitors suppress the growth of gastric cancer xenografts via induction of apoptosis in nude mice

To clarify the role of mitogen-inducible cyclooxygenase (COX-2) in the development of malignant tumors, we investigated the effects of COX-2 inhibitors on the growth of gastric cancer xenografts in nude mice in vivo. MKN45 gastric cancer cells (5 x 10(6) cells/animal) that overexpress COX-2 were inoculated subcutaneously into athymic mice. NS-398, a specific COX-2 inhibitor, or indomethacin, a nonspecific COX-2 inhibitor, was administered orally to animals every day for 20 days. These drugs reduced the tumor volume significantly. Immunohistochemistry using bromodeoxyuridine, nick end labeling, and electron microscopy showed that NS-398 induced apoptosis in cancer cells in a dose-dependent manner and inhibited cancer cell replication slightly. Indomethacin also induced apoptosis and suppressed replication of tumor cells. There was a significant negative correlation between tumor volume and apoptotic cell number within the tumor. These results are consistent with the hypothesis that COX-2 inhibitors suppress growth of gastric cancer xenografts mainly by inducing apoptosis and suppressing replication of the neoplastic cells. It follows that COX-2 plays an important role in the development of gastric cancer.

Tetrapod-type [Asp1] angiotensin is present in a holostean fish, Amia calva

The renin-angiotensin system has been identified in various vertebrates, from elasmobranchs to mammals. Tetrapod (amphibians to mammals) angiotensin (ANG) has Asp at the N-terminus, but Asp is replaced by Asn in elasmobranch and teleost fish. ANG I has been isolated from incubates of plasma and kidney extracts of the bowfin Amia calva, a holostean fish, using the eel vasopressor activity as an assay system; its sequence was found to be H-Asp-Arg-Val-Tyr-Val-His-Pro-Phe-Asn-Leu-OH after sequence analysis, mass spectrometry, and comparison with the synthetic peptide. This sequence is identical to bullfrog ANG I. [Asn1] ANG I was not detected. Thus the bowfin is the first fish species which contains only [Asp1] ANG I. The bowfin ANG I and II were no more vasopressor than eel peptides in the bowfin, indicating that bowfin ANG II receptors do not distinguish between [Asp1] and [Asn1] peptides. In the rat, bowfin ANG I and rat [Ile5, His9] ANG I have equipressor activities when examined in different animals, but the vasopressor activity of bowfin ANG I decreased following rat ANG I in the same animals, although the activity of rat ANG I was unaffected after bowfin ANG I. The present study directly demonstrates the presence of the renin-angiotensin system in a holostean fish and showed that its ANG II receptors have not yet fully coevolved with the homologous [Asp1] peptide.

Development of glycosylated human interleukin-1alpha, neoglyco IL-1alpha, coupled with D-galactose monosaccharide: biological activities in vivo

In our previous study, a galactose monosaccharide with C9 spacer was chemically coupled to recombinant human interleukin 1alpha (rhIL-1alpha) in order to study the effect of glycosylation on its activities, and to develop IL-1 with less deleterious effects. The glycosylated IL-la exhibited reduced activities in vitro by 10 to 10000-fold depending upon different aspects of activities addressed. The affinity to type I and II IL-1 receptors were also reduced. In this study we examined a variety of IL-1 activities in vivo, including upregulation of serum levels of IL-6, alpha1-acid glycoprotein, NOx, corticosterone, downregulation of serum level of glucose, and recovery of peripheral white blood cells (WBCs) from myelosuppression in 5-fluorouracil-treated mice. In contrast to the biological activities in vitro, these activities in vivo were uniformly reduced by only about 10 to 20-fold compared to untreated IL-1alpha.

Defect in synaptic vesicle precursor transport and neuronal cell death in KIF1A motor protein-deficient mice

The nerve axon is a good model system for studying the molecular mechanism of organelle transport in cells. Recently, the new kinesin superfamily proteins (KIFs) have been identified as candidate motor proteins involved in organelle transport. Among them KIF1A, a murine homologue of unc-104 gene of Caenorhabditis elegans, is a unique monomeric neuron- specific microtubule plus end-directed motor and has been proposed as a transporter of synaptic vesicle precursors (Okada, Y., H. Yamazaki, Y. Sekine-Aizawa, and N. Hirokawa. 1995. Cell. 81:769-780). To elucidate the function of KIF1A in vivo, we disrupted the KIF1A gene in mice. KIF1A mutants died mostly within a day after birth showing motor and sensory disturbances. In the nervous systems of these mutants, the transport of synaptic vesicle precursors showed a specific and significant decrease. Consequently, synaptic vesicle density decreased dramatically, and clusters of clear small vesicles accumulated in the cell bodies. Furthermore, marked neuronal degeneration and death occurred both in KIF1A mutant mice and in cultures of mutant neurons. The neuronal death in cultures was blocked by coculture with wild-type neurons or exposure to a low concentration of glutamate. These results in cultures suggested that the mutant neurons might not sufficiently receive afferent stimulation, such as neuronal contacts or neurotransmission, resulting in cell death. Thus, our results demonstrate that KIF1A transports a synaptic vesicle precursor and that KIF1A-mediated axonal transport plays a critical role in viability, maintenance, and function of neurons, particularly mature neurons.