The importance of initial daily administration of interferon alpha for the eradication of hepatitis C virus in patients with chronic hepatitis C: a multicenter randomized trial

BACKGROUND/AIMS

We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, to clarify a more effective treatment protocol for the eradication of the hepatitis C virus.

METHODOLOGY

Consecutive patients who met the inclusion criteria were randomly enrolled in two groups in this study. One hundred and five patients were randomized and assigned to two groups. Patients, who enrolled in group A, were treated with 6 million units of natural interferon-alpha given subcutaneously daily for an initial two weeks and then thrice a week for 22 weeks. Patients, who were enrolled in group B, were treated with the same dose of interferon-alpha given for 26 weeks thrice a week from the first administration.

RESULTS

In groups A and B, 58 and 47 patients were analyzed, respectively. At the end of treatment, 37 patients in group A (63.8%) had negative serum HCV-RNA test, compared with 26 in group B (55.3%), but at 6 months after discontinuation of interferon administration, 27 patients in group A (46.6%), compared with 8 in group B (21.3%). The rate of complete remission in group A (46.6%) was higher than that in group B (21.3%) (P<0.01). In patients with genotype 1b virus, the rate of complete remission was higher in group A (31.3%) than in group B (12.5%) (not significantly), and the relapse rate was lower in group A (9.4%) than in group B (37.5%), significantly (p<0.05).

CONCLUSIONS

This study suggests that initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with chronic hepatitis C.

Localization of a serine proteinase inhibitor, B-43, in the bovine pancreas

B-43, a serine proteinase inhibitor belonging to the ovalbumin branch of the serpin superfamily, was purified and cloned from bovine brain. Since [35S]-labeled B-43 forms SDS-stable complexes with pancreatic serine proteinases, trypsin, alpha-chymotrypsin, and kallikrein, it has been suggested that B-43 is capable of inhibiting these serine proteinases and that B-43 may be present in the pancreas. In the present study, we investigated the localization of B-43 in the bovine pancreas immunohistochemically and examined the effect of B-43 on the amidolytic activities of pancreatic serine proteinases. Strong B-43-like immunoreactivity was localized in acinar cells, especially in the basal sides of the cells where the rough endoplasmic reticulum is located. The nuclei of the subpopulation of acinar cells were also immunoreactive for B-43. The recombinant glutathione S-transferase-B-43 fusion protein inhibited the amidolytic activity of trypsin and, to a lesser extent, alpha-chymotrypsin and kallikrein, but not elastase. These results suggest a role of B-43 in regulating serine proteinases both in the cytoplasm and the nucleus.

Effects of cumulus cell density during in vitro maturation of the developmental competence of bovine oocytes

To determine the role of cumulus cells in oocyte maturation, we carried out an investigation on the effects of addition of cumulus cells to the maturation medium on the developmental competence of corona-enclosed oocytes and oocytes denuded from their somatic cells. The addition of cumulus cell (1.6 x 10(6) cells/mL) improved the development of bovine corona-enclosed oocytes, however, addition of a similar number of cumulus cells as cumulus-oocyte-complexes (COCs, cumulus cell density: 4.2 x 10(6) cells/mL) had no effect on the development of oocytes denuded from their somatic cells. To determine if corona-enclosed oocytes can obtain developmental competence without the addition of extra cumulus cells, the effects of cell density during in vitro maturation on the developmental competence were studied. A density of 1.6 to 3.2 x 10(6) cumulus cells/mL was the most effective for in vitro maturation of oocytes with intact gap junctions. The effects of the medium conditioned by COCs on the developmental competence of oocytes was also examined. It was demonstrated that COC-conditioned medium improved the development of bovine oocytes to the blastocyst stage. These data suggest that the developmental competence of bovine oocytes surrounded with corona cells is supported in a cell density-dependent manner in the maturation medium. In addition, the data indicate that cumulus cells benefit bovine oocyte development either by secreting soluble factors which induce developmental competence or by removing an embryo development-suppressive component from the medium.

Antimutagenic structural modification of quinoline assessed by an in vivo mutagenesis assay using lacZ-transgenic mice

Quinoline, a hepatocarcinogen, mutates the bacterial tester strains in the presence of the rat liver microsomal enzymes and induces GST-P (placental glutathione S-transferase)-positive foci in a medium-term bioassay system for hepatocarcinogenesis. On the other hand, 3-fluorinated quinoline was neither mutagenic nor carcinogenic in the same assay systems, whereas, 5-fluoroquinoline was mutagenic and carcinogenic. Quinoline was recently demonstrated to be mutagenic in an in vivo mutagenicity assay system using the lacZ-transgenic mouse (MutaMouse). The present study was undertaken to know whether 3-fluoroquinoline would be devoid of in vivo mutagenicity in MutaMouse. Quinoline and 5-fluoroquinoline were also tested in the same system. Mutagenicity was evaluated in the liver, the target organ of quinoline carcinogenesis, and also in the bone marrow and testis. The results strongly indicate that fluorine-substitution at the position-3 of quinoline could be an anti-genotoxic structural modification of quinoline in a wide range of its genotoxic end-points.

The rnf gene products in rhodobacter capsulatus play an essential role in nitrogen fixation during anaerobic DMSO-dependent growth in the dark

The rnf genes in Rhodobacter capsulatus are essential for nitrogen fixation in the light. Because R. capsulatus grows readily on N2 in the dark by anaerobic respiration with dimethylsulfoxide, the diazotrophic capacities of various strains in the dark were examined. No rnf mutants tested grew diazotrophically, and a nonpolar fdxN-null mutant showed decreased diazotrophic growth in the dark, suggesting that the Rnf and FdxN proteins form the primary electron donor pathway to nitrogenase in the dark as well as in the light. Nonphotosynthetic mutants lacking the component of cyclic electron transport grew diazotrophically and the levels of Rnf proteins were similar to those of the wild-type. These results indicate that rnf gene products play an essential role in nitrogen fixation without any functional link to the cyclic electron transport system.

Timing of completion of the first meiotic division in bovine oocytes after maintenance of meiotic arrest with cycloheximide and their subsequent development

This study examined the timing of completion of meiosis I of bovine oocytes in which meiotic resumption had been inhibited by cycloheximide (CHX), and also determined the optimum interval of maturation in culture for subsequent fertilization and development. Most oocytes treated with CHX reached metaphase II at 16 hr in the maturation culture, while control oocytes did at 20 hr. CHX-treated oocytes cultured for 16 hr were normally fertilized but failed to develop into blastocysts. Maturation in culture for 20 hr resulted in comparable development for control oocytes. The results indicate that nuclear maturation of CHX-treated oocytes was completed 4 hr faster than for control oocytes, however the same interval of maturation as that of control oocytes is necessary for subsequent development to blastocysts.

Prediction of efficacy of interferon treatment of chronic hepatitis C by multivariate analysis and a new classification

One hundred and fifteen patients with chronic hepatitis C were administered interferon (IFN) and classed into two groups: (i) complete responders (CR), HCV-RNA continuously negative 1 year after treatment; and (ii) non-responders (NR), positive 1 year after treatment. Multivariate analysis comprised eight variables: age, sex, transfusion history, alanine aminotransferase level, viral genotype, level of viremia, type of IFN, and total amount of IFN. The HCV-RNA level was correlated with complete response (P = 0.0175). Liver biopsy specimens were classified into four grades and stages according to the measure of severity and the extent of fibrosis, respectively. There was no correlation between the efficacy rate and grading. However, in staging there was a difference in the efficacy of IFN between stages 1 or 2, and stage 3 (0.05 < P < 0.1 and 0.01 < P < 0.025, respectively). Of the CR patients, 0% (0/5) were at stage 0 (no fibrosis); 27.5% (22/80) at stage 1 (mild); 42.9% (6/14) at stage 2 (moderate); and 6.3% (1/16) at stage 3 (severe fibrosis). Thus the new classification would be useful in predicting roughly the efficacy of IFN.

Bcl-2 expression and prognosis in childhood acute leukemia. Children's Cancer and Leukemia Study Group

Bcl-2 expression and its prognostic value were evaluated in 42 children with acute leukemia. The Bcl-2 expression of the leukemic blast cells was measured quantitatively by flow cytometry and was further analyzed by the simultaneous immunostaining of Bcl-2 with the surface membrane antigens, DNA, Ki-67 antigen. All of the cases showed a consistent expression of Bcl-2 protein; virtually all leukemic lymphoblasts were Bcl-2 positive. Although the expression of Bcl-2 varied widely from 7 to 80 x 10(3) MESF units, no significant difference was found in the mean value between the patients with acute lymphoblastic leukemia and those with acute myeloblastic leukemia. In more than half of the patients with AML, intraclonal heterogeneity of Bcl-2 expression was observed. The expression of Bcl-2 showed no apparent fluctuations during the different phases of the cell cycle. However, the proportion of Bcl-2-positive and -negative cells during the cell cycle was different between ALL and AML patients. In the ALL patients, few Bcl-2-negative cells were detected only in the GI phase, whereas in the AML patients Bcl-2-negative cells were detected in the S and G2/M phases, as well as in the G1 phase. No apparent difference was found in Bcl-2 expression between the Ki-67-negative noncycling population and the Ki-67-positive cycling population. Of the clinical features of these patients, only CD34 expression in the ALL patients was associated with high levels of Bcl-2 expression. In the 28 untreated cases of ALL, high expression of Bcl-2 was not an unfavorable factor for the outcome of this disease.

In vivo mutagenesis by the hepatocarcinogen quinoline in the lacZ transgenic mouse: evidence for its in vivo genotoxicity

Quinoline is carcinogenic to the liver of rats and mice and mutagenic to bacterial tester strains in the presence of rat liver microsomal enzymes. The unscheduled DNA synthesis (UDS) study suggested that quinoline might be a non-genotoxic carcinogen because of the lack of UDS-inducing capacity. In order to determine whether or not cancer induction is initiated by mutagenic DNA lesions, the present study was undertaken to evaluate the mutagenicity of quinoline in an in vivo mutation assay system using the lac Z transgenic mouse (Muta Mouse). Mutation was only induced in the liver, the target organ of carcinogenesis by quinoline, but not in the other organs examined, i.e. lung, kidney and spleen. Mutant frequency in the liver was 4-fold higher than in the untreated control animals. Dimethylnitrosamine, used as a positive control, induced mutation at a frequency 5-fold higher in the liver and 3-fold higher in the spleen than in their respective control organs. It can be concluded that the genotoxicity of quinoline is responsible for its hepatocarcinogenesis, although UDS was not induced under the conditions previously reported.

[Apoptosis of B lymphocytic leukemia induced by anticancer drugs and their cell cycle specificity]

OBJECTIVE

Evaluating the effect of apoptosis induced by anticancer drugs on human B lymphocytic leukemia cell lines (Nalm-6) and their cell cycle specificity.

METHODS

Nalm-6 cells were treated with various anticancer drugs for 8-24 hours. Apoptotic cells and their cell cycle specificity were measured by using hypodiploid DNA-FCM and TdT assay + DNA staining.

RESULTS

ADR, VP16, CPT, MTX, Ara-C could markedly induce apoptosis of Nalm-6 cells in S phase. CPM, PRD, 6MP were less capable of inducing apoptosis. CPM in high dose resulted in cell necrosis. PRD induced apoptosis in G1 phase, while 6MP induced apoptosis in G1 and S phase. The effect of CPM showed no marked cell cycle specificity.

CONCLUSION

Hypodiploid DNA-FCM and TdT assay + DNA staining can be used to detect both tumor cell apoptosis and their cell cycle specificity which is helpful to predict prognosis and to design new chemotherapy regimen.

Changes in monoamine turnover in the brain of cachectic mice bearing colon-26 tumor cells

Patients with cancer cachexia often suffer from psychiatric disorders. In the present study, we investigated the changes in monoaminergic activities in the brain in tumor-bearing mice with reference to the development of cachexia. Two clones, clone-5 (noncachectic clone) and clone-20 (cachectic clone), derived from the murine Colon-26 adenocarcinoma cell line (Nippon Roche Research Center), were inoculated subcutaneously at 1 x 10(6) cells/0.2 ml into the right lower back of BALB/c mice. In clone-20 mice, body weight and locomotor activity decreased significantly 10-15 days after tumor inoculation. The levels of noradrenaline, dopamine, and 3,4-dihydroxyphenylacetic acid showed no significant change among the three groups. The noradrenaline turnover rate in clone-20 mice was increased in cerebral cortex, hypothalamus, and midbrain. The 5-hydroxytryptamine turnover rate in clone-20 mice was increased in hippocampus, cerebral cortex, midbrain, and pons-medulla oblongata. In contrast, the dopamine turnover rate in clone-20 mice was decreased markedly in hippocampus, cerebral cortex, striatum, hypothalamus, and cerebellum. There was no significant change in amine turnover between control and clone-5 mice except for dopamine in hippocampus, cerebral cortex, and striatum and 5-hydroxytryptamine in striatum. No significant change in the levels of amino acids in the brain was observed among the three groups of mice. It is concluded that some of the psychiatric disorders from which cancer cachectic patients suffer might be ascribable to changes in monoaminergic activities in the brain.

Potent inhibition of cell density-dependent apoptosis and enhancement of survival by dimethyl sulfoxide in human myeloblastic HL-60 cells

Human myeloblastic cell line HL-60 cells undergo apoptosis during in vitro culture in a cell density-dependent manner, and this cell density-dependent apoptosis was observed when the concentration of cultured cells exceeded 8-10 x 10(5) cells/ml. Dimethyl sulfoxide (DMSO), a differentiation inducer of HL-60 cells, did not amplify, but rather potently inhibited, this apoptosis. In a low density culture condition, DMSO attenuated proliferation of HL-60 cells in spite of its inhibition of apoptosis. In contrast, DMSO did support cell survival under high cell density conditions, and DMSO-treated HL-60 cells reached an extremely high concentration of 2-3 x 10(6) cells/ml, a condition which could never be possible in a usual culture environment. Thus, DMSO exerted dual effects on cell proliferation, i.e., growth inhibition and apoptosis inhibition, and the sum of these effects resulted in an apparently distinct phenomenon according to the culture conditions including cell density.

Identification of spike protein residues of murine coronavirus responsible for receptor-binding activity by use of soluble receptor-resistant mutants

We previously demonstrated by site-directed mutagenesis analysis that the amino acid residues at positions 62 and 214 to 216 in the N-terminal region of mouse hepatitis virus (MHV) spike (S) protein are important for receptor-binding activity (H. Suzuki and F. Taguchi, J. Virol. 70:2632-2636, 1996). To further identify the residues responsible for the activity, we isolated the mutant viruses that were not neutralized with the soluble form of MHV receptor proteins, since such mutants were expected to have mutations in amino acids responsible for receptor-binding activity. Five soluble-receptor-resistant (srr) mutants isolated had mutations in a single amino acid at three different positions: one was at position 65 (Leu to His) (srr11) in the S1 subunit and three were at position 1114 (Leu to Phe) (srr3, srr4, and srr7) and one was at position 1163 (Cys to Phe) (srr18) in the S2 subunit. The receptor-binding activity examined by a virus overlay protein blot assay and by a coimmunoprecipitation assay showed that srr11 S protein had extremely reduced binding activity, while the srr7 and srr18 proteins had binding activity similar to that of wild-type cl-2 protein. However, when cell surface receptors were used for the binding assay, all srr mutants showed activity similar to that of the wild type or only slightly reduced activity. These results, together with our previous observations, suggest that amino acids located at positions 62 to 65 of S1, a region conserved among the MHV strains examined, are important for receptor-binding activity. We also discuss the mechanism by which srr mutants with a mutation in S2 showed high resistance to neutralization by a soluble receptor, despite their sufficient level of binding to soluble receptors.

Developmental capacity of bovine oocytes following inhibition of meiotic resumption by cycloheximide or 6-dimethylaminopurine

This study was conducted to assess the fertilizability and developmental capacity of bovine oocytes which had been maintained in meiotic arrest by either a protein synthesis inhibitor, cycloheximide (CHX), or an inhibitor of serine/threonine protein kinases, 6-dimethylaminopurine (6-DMAP). Both CHX and 6-DMAP reversibly prevented nuclear maturation of nearly all oocytes for 24 h. After the reversal of arrest, CHX-treated oocytes could be successfully matured and fertilized. They developed to the blastocyst stage at slightly lower rates than oocytes cultured without inhibition for 22 h prior to sperm addition but at higher rates than those incubated in a medium containing no inhibitors for 46 h prior to fertilization. Oocytes inhibited by CHX for 48 h matured and fertilized normally but failed to develop into blastocysts. Even though 6-DMAP-treated oocytes completed meiosis I after removal from the drug, the rates of fertilization and blastocyst formation were lower than for untreated oocytes or CHX-treated oocytes. Effects of adding FSH and/or estradiol-17 beta (E(2)) during CHX-inhibition for 24 h were also examined. Embryos from oocytes treated with CHX and E(2) or with CHX and FSH + E(2) developed into blastocysts at similar rates as the controls. Further development of inhibited oocytes was examined by transferring blastocysts derived from oocytes inhibited by CHX with FSH and E(2) for 24 h to recipient heifers. Two calves were obtained following transfer. These results indicate that CHX-inhibited oocytes retain developmental competence, while 6-DMAP-inhibited oocytes after the reversal of arrest have reduced capacities for fertilization and further development. The addition of FSH and E(2) during CHX-inhibition improves development to the blastocyst stage of the oocytes that are capable of initiating and maintaining pregnancy after embryo transfer to recipient animals.

Cell density-dependent apoptosis in HL-60 cells, which is mediated by an unknown soluble factor, is inhibited by transforming growth factor beta1 and overexpression of Bcl-2

We report a novel mode of apoptosis induction observed in human leukemic HL-60 cells. These cells spontaneously underwent apoptosis in the course of proliferation when the cell density became higher than 1 x 10(6)/ml. This occurred under ordinary in vitro culture conditions, with or without fetal calf serum. Even the low density cells were committed to undergo apoptosis if they were cultured under artificially concentrated conditions. Replacement of the culture supernatant of the low density cells by that of the high density ones resulted in apoptosis induction in the former cells. This apoptosis-inducing activity of the high density cell culture supernatant was completely eliminated by the action of trypsin but was fully restored following ultrafiltration by 3-kDa pore-sized membrane. A strong apoptosis-inducing activity was recovered from the culture supernatant of the high density HL-60 cells at a specific fraction in reverse-phase column chromatography. Neither an interleukin-beta converting enzyme inhibitor nor CPP-32 inhibitor blocked the induction of cell density-dependent apoptosis in HL-60 cells, although overexpression of Bcl-2 protein markedly attenuated the induction of this mode. Surprisingly, transforming growth factor-beta1 and activin A did not induce but, rather, inhibited the induction of cell density-dependent apoptosis. These data suggest that HL-60 cells release an unknown low molecular weight peptide-containing factor in response to an increase in cell density to induce apoptosis in an autocrine manner and that the interleukin-beta converting enzyme-independent intracellular machinery for this mode of apoptosis is strongly affected by signaling events through the transforming growth factor-beta1 receptor and by the action of Bcl-2 oncoprotein.

Subglottic stenosis in Wegener's granulomatosis limited to the head and neck region

Subglottic stenosis as a complication of Wegener's granulomatosis (WG) is a relatively rare lesion and is difficult to treat surgically once stenosis becomes sufficiently severe to cause inspiratory dyspnea. Thus, it is important to diagnose WG in its early stages to prevent troublesome subglottic stenosis from developing by initiating immunosuppressive therapy. The authors report on a 30-year-old woman suffering from subglottic stenosis of sudden onset due to protracted WG limited to the head and neck region. She had had exudative otitis media for 13 years and saddle nose and nasal crusting for five years. Repeated biopsies of the nasal mucosa and enzyme-linked immunosorbent assays for cytoplasmic patterns of antineutrophil cytoplasmic autoantibody (cANCA) had failed to establish the diagnosis. However, further histologic examination of the nasal mucosa showed vasculitis, and indirect immunofluorescence detected the presence of cANCA. Thus, the diagnosis of WG was confirmed 13 years after the appearance of the initial symptoms in the ear. The patient was given prednisolone (60 mg/day for five days), which greatly relieved the subglottic stenosis. The prednisolone dosage was then tapered to 5 mg/day.

Differential induction of apoptosis on human lymphoblastic leukemia Nalm-6 and Molt-4 cells by various antitumor drugs

To investigate how chemotherapy agents interact with the leukemic cell death pathway, we examined apoptosis of human lymphoblastic leukemia cells (Nalm-6 and Molt-4) treated with various anticancer drugs (etoposide (VP-16), camptothecin (CPT), adriamycin (ADR), cytosine arabinoside (Ara-C), methotrexate (MTX), 6 mercaptopurine (6MP), cyclophosphamide (CPM), vincristine (VCR) and prednisolone (PRD)) by flow cytometric procedures. The proportion of apoptotic cells was estimated from the presence of cells with a fractional DNA content in the DNA histograms after the incubation of drug-treated cells with a DNA extraction buffer. Treatment with Ara-C, CPT, VP-16 and ADR resulted in rapid apoptosis with 40-60% apoptotic cells by 8 h. Treatment with MTX, VCR, 6MP and PRD induced no apparent apoptosis until 12 h, but further treatments with these drugs resulted in apoptosis with 50% (MTX), 20-30% (6MP and VCR) and 5-10% (PRD) apoptotic cells, respectively, at 24 h. CPM induced apoptosis with 10-20% apoptotic cells at 10(-6) M, but higher doses (> 10(-5) M) caused a rapid cell death by necrosis. The cell cycle position of apoptotic cells was assessed by the terminal deoxynucleotidyl transferase (TdT) assay of DNA strand breaks combined with DNA staining. MTX, Ara-C, CPT, VP-16 and ADR preferentially induced apoptosis in the S phase. PRD and 6MP induced apoptosis in the G1 phase and G1 + S phases, respectively. CPM showed no cell cycle phase specificity. These findings suggested that the susceptibility of cells to apoptosis was not the sole determinant of cellular sensitivity of cytotoxic drugs.

Dual stimulatory and inhibitory effects of fluorine-substitution on mutagenicity: an extension of the enamine epoxide theory for activation of the quinoline nucleus

Nineteen mono- and di-fluorinated derivatives of quinoline, 1,7-phenanthroline, 1,10-phenanthroline, benzo[h]quinoline, and benzo[f]quinoline were subjected to analysis of their structure-mutagenicity relationships. For this purpose, six new fluorinated derivatives were synthesized. The results support that the enamine epoxide structure of the pyridine moiety, as well as the bay-region epoxide structure, is responsible for mutagenicity. Formation of K-region epoxides might involve a detoxification process rather than mutagenic activation.

Immunohistochemical localization of macrophage migration inhibitory factor (MIF) in tanycytes, subcommissural organ and choroid plexus in the rat brain

We investigated the immunohistochemical localization of the macrophage migration inhibitory factor (MIF) in the rat brain. In addition to epithelial ependymal cells lining the ventricular wall, tanycytes in the basomedial hypothalamus were heavily immunostained. The immunoreactive processes of tanycytes made contacts to sinusoidal capillaries and reached the pial surface forming an immuno-positive structure at the floor of the hypothalamus. Other immunoreactive cells contained the subcommissural organ in the roof of the third ventricle and the epithelial lamina of the choroid plexus. The localization of MIF in cells which have contact with cerebrospinal fluid and blood vessels suggests that MIF might play a role as a humoral factor in the brain.

Membrane localization, topology, and mutual stabilization of the rnfABC gene products in Rhodobacter capsulatus and implications for a new family of energy-coupling NADH oxidoreductases

The rnf genes in Rhodobacter capsulatus are unique nitrogen fixation genes that encode potential membrane proteins (RnfA, RnfD, and RnfE) and potential iron-sulfur proteins (RnfB and RnfC). In this study, we first analyzed the localization and topology of the RnfA, RnfB, and RnfC proteins. By activity and immunoblot analysis of expression of translational fusions to Escherichia coli alkaline phosphatase, RnfA protein was shown to span the chromatophore membrane with its odd-numbered hydrophilic regions exposed to periplasm. By alkaline treatment of membrane fractions and following immunoblot analysis using antibodies against recombinant proteins expressed in E. coli, both RnfB and RnfC proteins were revealed to situate at the periphery of the chromatophore membranes. Second, mutual interaction of the Rnf proteins was analyzed by immunochemical determinations of RnfB and RnfC proteins in rnf mutants and their complemented derivatives. The contents in cellular fractions indicated that RnfB and RnfC stabilize each other and that the presence of RnfA is necessary for stable existence of both proteins. These results support a hypothesis that the Rnf products are subunits of a membrane complex. Finally, we detected homologs of rnf genes in Haemophilus influenzae and Vibrio alginolyticus by data base searches and in E. coli by cloning of a fragment of an rnfA homolog followed by a data base search. Close comparisons revealed that RnfC has potential binding sites for NADH and FMN which are similar to those found in proton-translocating NADH:quinone oxidoreductases and that RnfA, RnfD, and RnfE show similarity to subunits of sodium-translocating NADH:quinone oxidoreductases. We predict that the putative Rnf complex represents a novel family of energy-coupling NADH oxidoreductases.

Identification of bradykinin, substance P, and neurokinin A in human dental pulp

Methodology was developed that uses reverse phase, high performance liquid chromatography (HPLC) to identify and quantify bradykinin, substance P, and neurokinin A contained in dental pulp tissue. Pulp tissue was prepared and homogenized from teeth frozen in liquid nitrogen, Known amounts of three substances found in inflamed tissue were added to the homogenized tissue and also to bovine serum albumin (BSA) (positive control), and supernatants were analyzed using HPLC. Other pulp tissue was prepared and analyzed without the addition of the substances. Recovery from the pulp and BSA with added substances was similar, with bradykinin recovered maximally. In pulp tissue without additions, all three substances were recovered. Thus HPLC appears to be a viable alternative to other methods for identification of these substances and allows for their quantification.

cDNA cloning, tissue distribution, and subcellular localization of horseshoe crab big defensin

A full-length cDNA for horseshoe crab big defensin with a strong antimicrobial activity was obtained from a hemocyte cDNA library. The open reading frame of the cDNA coded for an NH2-terminal signal sequence followed by a propeptide and the mature big defensin. The propeptide is linked to the mature protein through an -Arg-X-Lys/Arg-Arg- motif, the processing site for Kex2-like proteases. Northern blot analysis revealed that big defensin is expressed in all the tissues tested, suggesting that big defensin plays an important role not only in hemocytes but also in other tissues for host defense. The subcellular localization, determined by immunocytochemistry at ultrastructural level, confirmed the previous findings obtained by biochemical analysis that big defensin locates in both small and large granules in hemocytes. Big defensin is the first example to demonstrate the existence of broad tissue distribution in horseshoe crab.