Full-thickness surgical excision for the treatment of inflammatory linear verrucous epidermal nevus

Inflammatory linear verrucous epidermal nevus (ILVEN) is a benign cutaneous hamartoma characterized by intensely erythematous, pruritic, inflammatory papules that occur as linear bands along the lines of Blaschko. Because of its chronic and unremitting symptomatology, patients with ILVEN seek medical treatment for relief of discomfort as well as concerns regarding cosmetic appearance. Reported therapeutic approaches include topical agents, dermabrasion, cryotherapy, laser therapy, and partial-thickness excision. Unfortunately, no one therapy has been successful consistently. Medical management is often unsatisfactory, because improvement tends to be temporary. Surgical modalities have met with better success in relief of symptoms but at the risk of marked scarring and a high rate of recurrence. Furthermore, the occurrence of extensive ILVEN or localization to certain anatomic regions has been considered previously a relative contraindication to excision. The authors report 4 patients with extensive ILVEN treated successfully with full-thickness surgical excision. Our report underscores the effectiveness of this surgical modality for the definitive treatment of ILVEN.

Borna disease virus phosphoprotein binds a neurite outgrowth factor, amphoterin/HMG-1

The Borna disease virus (BDV) p24 phosphoprotein is an abundant protein in BDV-infected cultured cells and animal brains. Therefore, there is a possibility that binding of the p24 protein to cellular factor(s) induces functional alterations of infected neural cells in the brain. To identify a cellular protein(s) that interacts with BDV p24 protein, we performed far-Western blotting with extracts from various cell lines. Using recombinant p24 protein as a probe, we detected a 30-kDa protein in all cell lines examined. Binding between the 30-kDa and BDV p24 proteins was also demonstrated using BDV p24 affinity and ion-exchange chromatography columns. Microsequence analysis of the purified 30-kDa protein revealed that its N terminus showed complete homology with rat amphoterin protein, which is a neurite outgrowth factor abundant in the brain during development. Mammalian two-hybrid and immunoprecipitation analyses also confirmed that amphoterin is a specific target for the p24 protein in vivo. Furthermore, we showed that infection by BDV, as well as purified p24 protein in the medium, significantly decreased cell process outgrowth of cells grown on laminin, indicating the functional inhibition of amphoterin by interaction with the p24 protein. Immunohistochemical analysis revealed decreased levels of amphoterin protein at the leading edges of BDV-infected cells. Moreover, the expression of the receptor for advanced glycation end products, of which the extracellular moiety is a receptor for amphoterin, was not significantly activated in BDV-infected cells during the process of extension, suggesting that the secretion of amphoterin from the cell surface is inhibited by the binding of the p24 protein. These results suggested that BDV infection may cause direct damage in the developing brain by inhibiting the function of amphoterin due to binding by the p24 phosphoprotein.

Binding aspects of baicalein to HIV-1 integrase

Human immunodeficiency virus type 1 (HIV-1) integrase is an essential enzyme in the life cycle of the virus. It is responsible for catalyzing the insertion of the viral genome into the host cell chromosome. This integrase is an attractive target for the design of a HIV antiviral drug, because integrase has no human counterpart. In order to know the interaction mode of HIV-1 integrase with its inhibitor, we investigated the effect of the inhibitor, baicalein, on the conformation of the HIV-1 integrase catalytic domain [IN-(50-212/F185K)] using fluorescence and circular dichroism (CD) spectroscopy. We found that baicalein binds to the hydrophobic region of the HIV-1 integrase catalytic core domain. This binding of baicalein induces the conformational change of the enzyme. We also found that the binding ratio of baicalein to the HIV-1 integrase catalytic domain is 2:1.

Selenium metabolism in Drosophila: selenoproteins, selenoprotein mRNA expression, fertility, and mortality

Selenocysteine is a rare amino acid in protein that is encoded by UGA with the requirement of a downstream mRNA stem-loop structure, the selenocysteine insertion sequence element. To detect selenoproteins in Drosophila, the entire genome was analyzed with a novel program that searches for selenocysteine insertion sequence elements, followed by selenoprotein gene signature analyses. This computational screen and subsequent metabolic labeling with (75)Se and characterization of selenoprotein mRNA expression resulted in identification of three selenoproteins: selenophosphate synthetase 2 and novel G-rich and BthD selenoproteins that had no homology to known proteins. To assess a biological role for these proteins, a simple chemically defined medium that supports growth of adult Drosophila and requires selenium supplementation for optimal survival was devised. Flies survived on this medium supplemented with 10(-8) to 10(-6) m selenium or on the commonly used yeast-based complete medium at about twice the rate as those on a medium without selenium or with >10(-6) m selenium. This effect correlated with changes in selenoprotein mRNA expression. The number of eggs laid by Drosophila was reduced approximately in half in the chemically defined medium compared with the same medium supplemented with selenium. The data provide evidence that dietary selenium deficiency shortens, while supplementation of the diet with selenium normalizes the Drosophila life span by a process that may involve the newly identified selenoproteins.

Simultaneous determination of multiple transcripts and splice variants of a primary transcript using ribonuclease protection assays

The ribonuclease (RNase) protection assay (RPA) is an extremely sensitive technique used to determine specific mRNAs from cell and tissue extracts. The present protocol presents detailed procedures for a conventional RPA using antisense RNA probes purified with a Fullengther apparatus. The Fullengther has the advantage of being a relatively quick and safe procedure compared to more conventional methods for purification of full-length RNA probes. Using this protocol, we sought to simultaneously determine multiple mRNA species, including splice variants of the type I receptor (PAC(1)) of pituitary adenylate cyclase-activating polypeptide (PACAP), an important mediator in the regulation of luteinizing hormone-releasing hormone (LHRH) synthesis by ovarian steroids such as progesterone [7]. PAC(1) has more than eight splice variants. We have been able to discriminate the hop1 variant from other splice variants. To improve our understanding of the regulation mechanism of genes that are related to each other, such as LHRH and PACAP, it is most important to simultaneously determine genes that are involved in the same physiological areas of regulation. Using only 5 microg of total RNA sample from a single rat preoptic area, we simultaneously determined five different transcripts, including four rare mRNA species such as LHRH, PACAP, and hop1 variant and other splice variants of PAC(1), as well as the internal control of cyclophilin mRNA. This protocol provides a method for the simultaneous determination of multiple transcripts using the RPA.

Detection of the protein-protein interaction between cyclic AMP receptor protein and RNA polymerase, by (13)C-carbonyl NMR

Cyclic AMP receptor protein (CRP) plays a key role in the transcription regulation of many prokaryotic genes. Upon the binding of cyclic AMP, CRP is allosterically activated, binds to target DNA sites, and interacts with RNA polymerase. Although the protein-protein interaction between CRP and RNA polymerase is known to be important for the transcription initiation of the target genes, its structural understanding is still lacking, particularly due to the high molecular mass (approximately 120 kDa) of the protein complex. We assigned all of the (13)C-carbonyl resonances of methionine residues in CRP by using the double labeling and the enzyme digestion techniques. The result of (13)C-carbonyl NMR experiment on [(13)C'-Met]-CRP in the presence of both cyclic AMP and RNA polymerase alpha subunit showed that the two proteins interact with each other in solution in the absence of DNA via the region around the residues from Met 157 to Met 163 in CRP. The results also showed the effectiveness of the selective labeling and (13)C-carbonyl NMR spectroscopy in the specific detection of the protein-protein interaction between large molecules.

Selective inhibition of selenocysteine tRNA maturation and selenoprotein synthesis in transgenic mice expressing isopentenyladenosine-deficient selenocysteine tRNA

Selenocysteine (Sec) tRNA (tRNA([Ser]Sec)) serves as both the site of Sec biosynthesis and the adapter molecule for donation of this amino acid to protein. The consequences on selenoprotein biosynthesis of overexpressing either the wild type or a mutant tRNA([Ser]Sec) lacking the modified base, isopentenyladenosine, in its anticodon loop were examined by introducing multiple copies of the corresponding tRNA([Ser]Sec) genes into the mouse genome. Overexpression of wild-type tRNA([Ser]Sec) did not affect selenoprotein synthesis. In contrast, the levels of numerous selenoproteins decreased in mice expressing isopentenyladenosine-deficient (i(6)A(-)) tRNA([Ser]Sec) in a protein- and tissue-specific manner. Cytosolic glutathione peroxidase and mitochondrial thioredoxin reductase 3 were the most and least affected selenoproteins, while selenoprotein expression was most and least affected in the liver and testes, respectively. The defect in selenoprotein expression occurred at translation, since selenoprotein mRNA levels were largely unaffected. Analysis of the tRNA([Ser]Sec) population showed that expression of i(6)A(-) tRNA([Ser]Sec) altered the distribution of the two major isoforms, whereby the maturation of tRNA([Ser]Sec) by methylation of the nucleoside in the wobble position was repressed. The data suggest that the levels of i(6)A(-) tRNA([Ser]Sec) and wild-type tRNA([Ser]Sec) are regulated independently and that the amount of wild-type tRNA([Ser]Sec) is determined, at least in part, by a feedback mechanism governed by the level of the tRNA([Ser]Sec) population. This study marks the first example of transgenic mice engineered to contain functional tRNA transgenes and suggests that i(6)A(-) tRNA([Ser]Sec) transgenic mice will be useful in assessing the biological roles of selenoproteins.

Differences in sensitization rates to outdoor aeroallergens, especially citrus red mite (Panonychus citri), between urban and rural children

BACKGROUND

A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is the most important allergen in citrus-cultivating farmers with asthma and allergic rhinitis.

OBJECTIVE

A cross-sectional survey was performed to evaluate the prevalence of asthma and chronic rhinitis symptoms and sensitization to common indoor and outdoor aeroallergens, including CRM and Japanese cedar pollen, in rural and urban Korean children.

METHODS

A total of 2,055 children (1,055 subjects living in rural areas with citrus farms and 1,000 controls in urban areas without citrus farms) were enrolled. They were evaluated by a questionnaire, and by skin prick tests with 13 common indoor and outdoor aeroallergens, including CRM and Japanese cedar pollen.

RESULTS

The prevalence of wheezing and chronic rhinitis symptoms during the last 12 months was 8.3% and 35.7% in the rural children and 10.5% and 22.4% in the control group. The most common sensitizing allergens in order of decreasing frequency were Dermatophagoides pteronyssinus (26.6%), Dermatoplagoides farinae (22.7%), CRM (14.2%), cockroach (11.3%), and Japanese cedar pollen (9.7%) among the rural children, but the sensitization rates to CRM and Japanese cedar pollen were 1.3% and 0.2% among the control children, respectively. The prevalence of wheeze during the last 12 months was not different between rural children with sensitization to CRM or Japanese cedar pollen and those without sensitization (5.4% vs 6.1%; 6.9% vs 5.9%). However, the prevalence of chronic rhinitis during the last 12 months was higher among those with sensitization to CRM or to Japanese cedar pollen than among those without sensitization (40.8% vs 34.4%; 51.5% vs 33.5%).

CONCLUSIONS

CRM is a common sensitizing allergen in rural children, and the sensitization rates to outdoor aeroallergens, especially CRM and Japanese cedar pollen, are very different between children from rural and urban areas in Korea.

Stimulation via CD40 can substitute for CD4 T cell function in preventing reactivation of a latent herpesvirus

Reactivation of latent herpesviruses is a particular problem in immunocompromised individuals, such as AIDS patients, who lack effective CD4 T helper cell function. An important question is whether residual immune defenses can be mobilized to combat such opportunistic infections, in the absence of CD4 T cells. In the present study, we used a mouse model of opportunistic infection to determine whether stimulation via CD40 could substitute for CD4 T cell function in preventing reactivation of a latent herpesvirus. Treatment with an agonistic antibody to CD40 was highly effective in preventing reactivation of latent murine gammaherpesvirus (MHV-68) in the lungs of CD4 T cell-deficient mice. CD8(+) T cells were essential for this effect, whereas virus-specific serum antibody was undetectable and IFN-gamma production was unchanged. This demonstration that immunostimulation via CD40 can replace CD4 T cell help in controlling latent virus in vivo has potential implications for the development of novel therapeutic agents to prevent viral reactivation in immunocompromised patients.

Effect of ethylene glycol monoethyl ether on the spermatogenesis in pubertal and adult rats

The effects of ethylene glycol monoethyl ether (EGEE) on testicular cell populations in pubertal (5 weeks old) and adult (9 weeks old) male rats were investigated by a flow cytometric method. A total of 50 rats (in number, 25 pubertal and 25 adult rats) was divided into 5 experimental groups including 0 (control), 50, 100, 200, and 400 mg EGEE/kg of body weight. The animals were administered by gavage for 4 weeks. In adult rats, the treatment of EGEE at the dose of 400 mg/kg of body weight decreased significantly the populations of haploid, while it increased those of diploid and tetraploid cells. In pubertal rats, the treatment of EGEE at the dose of 400 mg/kg of body weight caused only minimal changes in the relative percent of testicular cell types. These results suggest that the effects of EGEE on testicular function in pubertal rats appear to be less pronounced than in adult rats.

Effects of nonylphenol, bisphenol A, and their mixture on the viviparous swordtail fish (Xiphophorus helleri)

A number of fish species have been used for studies on endocrine disrupting chemicals (EDCs). However, despite the widespread use of oviparous fish, relatively little attention has been given to viviparous species. This study investigated the effects of EDCs in a viviparous fish and examined the possible usefulness of the fish as an alternative model for the studies on EDCs. Swordtails (Xiphophorus helleri) were exposed to nonylphenol (NP), bisphenol A (BPA), and their mixture. Both short-term (3-d) and relatively long-term (60-d) exposures were carried out using adult male and 30-d-old juvenile fish, respectively. Following the short-term exposure, both NP and BPA caused vitellogenin mRNA expression. Flow cytometric analysis and terminal deoxynucleotidyl transferase assay on the testes of treated fish indicated reproductive damage. Histopathological analysis found degenerative and necrotic cells in seminiferous tubules following the exposure to 100 ppb NP. The testes with lesions were also associated with highly suppressed spermatogenesis. Following the long-term exposure, both NP and BPA exposures significantly affected the growth of swordtails. In all cases, the results showed that the mixture was always more potent than a single chemical and that swordtail fish can be a useful model for the study of endocrine disruptors.

Solution structure of the SL1 RNA of the M1 double-stranded RNA virus of Saccharomyces cerevisiae

The 20-nucleotide SL1 VBS RNA, 5'-GGAGACGC[GAUUC]GCGCUCC (bulged A underlined and loop bases in brackets), plays a crucial role in viral particle binding to the plus strand and packaging of the RNA. Its structure was determined by NMR spectroscopy. Structure calculations gave a precisely defined structure, with an average pairwise root mean square deviation (RMSD) of 1.28 A for the entire molecule, 0.57 A for the loop region (C8-G14), and 0.46 A for the bulge region (G4-G7, C15-C17). Base stacking continues for three nucleotides on the 5' side of the loop. The final structure contains a single hydrogen bond involving the guanine imino proton and the carbonyl O(2) of the cytosine between the nucleotides on the 5' and 3' ends of the loop, although they do not form a Watson-Crick base pair. All three pyrimidine bases in the loop point toward the major groove, which implies that Cap-Pol protein may recognize the major groove of the SL1 loop region. The bulged A5 residue is stacked in the stem, but nuclear Overhauser enhancements (NOEs) suggest that A5 spends part of the time in the bulged-out conformation. The rigid conformation of the upper stem and loop regions may allow the SL1 VBS RNA to interact with Cap-Pol protein without drastically changing its own conformation.

Flow cytometric evaluation on the age-dependent changes of testicular DNA contents in rats

An age-dependent cellular change of DNA contents in the testis of Sprague-Dawley rats was investigated by flow-cytometric method. Testicular cell suspensions at the age of 4, 5, 6, 7, 8, 10, 12, 16 and 26 weeks were prepared and stained with propidium iodide. The relative proportions in the number of mature and immature haploid (1n), diploid (2n), S-phase and tetraploid (4n) cells were calculated. The proportion in the number of mature haploid cells was sharply increased to the age of 10 weeks (about 38%), thereafter increased slightly to the level of 42% at the age of 26 weeks. The proportion of immature haploid cells was dramatically increased to the age of 6 weeks, then maintained at the level of 20 to 30% thereafter. The proportion of diploid cells was 64% at the age of 4 weeks, then decreased gradually through the age of 26 weeks. The proportion of S-phase cells was increased to the age of 4 weeks, then maintained at a plateau level to the age of 26 weeks. The proportion of tetraploid cells were about 26% at the age of 4 weeks, then decreased gradually to the age of 26 weeks. These results suggest that the proportions of testicular cells may depend on the age of the rat and that the flow cytometric method may be useful in the evaluation of the spermatogenic status with regard to accuracy and sensitivity.

Neurological diseases and viral dynamics in the brains of neonatally borna disease virus-infected gerbils

Borna disease virus (BDV) is a noncytolytic, neurotropic RNA virus that causes a chronic neurological disease in a wide variety of animal species. To develop a better understanding of the correlation between neurological disorders caused by BDV infection and virus distribution in the brain, we investigated viral dynamics in the central nervous system (CNS) of neonatally BDV-infected gerbils during the late stage of infection. Despite the severe symptoms and aggressive proliferation of BDV in the infected gerbils, no apparent neuroanatomical abnormalities or neuronal cell loss was observed in the infected gerbil brain. Furthermore, no or only minimal infiltration was observed in the infected gerbil brain. By in situ hybridization and real-time PCR analyses, we demonstrated that the predominant area of expression of BDV mRNA, as well as the protein, was shifted in the brain in association with progression of disease. In nondiseased gerbils, the virus replication was predominantly detected in the cerebral cortex and hippocampus of the CNS. On the other hand, diseased animals showed a high level of expression in the lower brain stem and cerebellum, especially in Purkinje cell neurons. These observations suggested that significant replication of the virus in specific areas of the CNS is critical for development of the neurological disorders in BDV-infected neonatal gerbils.

No association between presenilin 1 (PS1) intronic polymorphism and sporadic Alzheimer's disease in Koreans

To investigate the possible involvement of an intronic polymorphism in the presenilin 1 (PS1) gene and its interactions with the aplolipoprotein E (APOE) or alpha-1 antichymotrypsin (ACT) polymorphisms in the manifestation of AD, we analyzed the PS1, APOE and ACT genotypes of 100 sporadic AD patients and 199 normal elderly controls in Koreans. The genotypic (chi2= 0.92, df = 2, P > 0.1) and allelic (chi2 = 0.01, df = 1, P > 0.1) frequencies of the PS1 polymorphism in the late- and early-onset sporadic AD patients did not differ from those in the controls. And the occurrence of the APOE epsilon4 allele and ACT A allele did not influence the distribution of the PS1 intronic polymorphism. The PS1 intronic polymorphism didn't influence the age-at-onset of AD (F = 0.02, df = 2, P > 0.1). In conclusion, the PS1 intronic polymorphism did not modify the risk for sporadic AD, neither independently nor synergistically with the APOE epsilon4 allele or ACT A allele, in Koreans.

Glia-to-neuron signaling and the neuroendocrine control of female puberty

It is becoming increasingly clear that astroglial cells are active participants in the process by which information is generated and disseminated within the central nervous system (CNS). In the hypothalamus, astrocytes regulate the secretory activity of neuroendocrine neurons. They contribute to facilitating sexual development by stimulating the release of luteinizing hormone-releasing hormone (LHRH), the neuropeptide that controls sexual development, from LHRH neurons. Astrocytes secrete several growth factors able to stimulate LHRH secretion. Two members of the epidermal growth factor (EGF) family--transforming growth factor alpha (TGFalpha) and the neuregulins (NRGs)-are produced in hypothalamic astrocytes and elicit LHRH secretion indirectly, via activation of receptor complexes formed by three members of the EGF receptor family, also located on astrocytes. Activation of these receptors results in the production of at least one neuroactive substance, prostaglandin E2 (PGE2), which stimulates LHRH secretion upon binding to specific receptors on LHRH neurons. Overexpression of TGFalpha in the hypothalamus accelerates puberty, whereas blockade of either TGFalpha or NRG actions delays the process, indicating that both peptides are physiological components of the neuroendocrine mechanism that controls sexual maturation. An increase in hypothalamic expression of at least two of the erbB receptors is initiated before the pubertal augmentation of gonadal steroid secretion and is completed on the day of the first preovulatory surge of gonadotropins. This secondary increase is brought about by gonadal steroids. Estrogen and progesterone facilitate erbB-mediated glia-to-LHRH neuron communication by enhancing astrocytic gene expression of at least one of the EGF-related ligands (TGFalpha) and two of the receptors (erbB-2 and erbB-4). They also facilitate the LHRH response to PGE2 via induction of PGE2 receptors in LHRH neurons. A search for genes that may act as upstream regulators of the pubertal process resulted in the identification of two potential candidates: Oct-2, a POU domain gene originally described in cells of the immune system, and TTF-1, a member of the Nkx family of homeodomain transcriptional regulators required for diencephalic morphogenesis. The hypothalamic expression of both genes increases during juvenile development before the first hormonal manifestations of puberty take place. Their mRNA transcripts are localized to specific hypothalamic cellular subsets, where they appear to regulate different, but interactive, components of the neuronal-glial complex controlling LHRH secretion. While Oct-2 transactivates the TGFalpha promoter, TTF-1 does so to the erbB-2 and LHRH genes but inhibits preproenkephalin promoter activity, suggesting that both transcriptional regulators may act coordinately in the normal hypothalamus to activate genes involved in facilitating the advent of puberty and repress those restraining sexual development. Altogether, these observations indicate that the central activation of the pubertal process involves the participation of both neuronal and astroglial networks and the contribution of upstream transcriptional regulators acting on both the neuronal and glial components of the system.

1-Methylguanosine in place of Y base at position 37 in phenylalanine tRNA is responsible for its shiftiness in retroviral ribosomal frameshifting

Many mammalian retroviruses express their protease and polymerase by ribosomal frameshifting. It was originally proposed that a specialized shifty tRNA promotes the frameshift event. We previously observed that phenylalanine tRNA(Phe) lacking the highly modified wybutoxosine (Y) base on the 3' side of its anticodon stimulated frameshifting, demonstrating that this tRNA is shifty. We now report the shifty tRNA(Phe) contains 1-methylguanosine (m(1)G) in place of Y and that the m(1)G form from rabbit reticulocytes stimulates frameshifting more efficiently than its m(1)G-containing counterpart from mouse neuroblastoma cells. The latter tRNA contains unmodified C and G nucleosides at positions 32 and 34, respectively, while the former tRNA contains the analogous 2'-O-methylated nucleosides at these positions. The data suggest that not only does the loss of a highly modified base from the 3' side of the anticodon render tRNA(Phe) shifty, but the modification status of the entire anticodon loop contributes to the degree of shiftiness. Possible biological consequences of these findings are discussed.

TTF-1, a homeodomain gene required for diencephalic morphogenesis, is postnatally expressed in the neuroendocrine brain in a developmentally regulated and cell-specific fashion

TTF-1 is a member of the Nkx family of homeodomain genes required for morphogenesis of the hypothalamus. Whether TTF-1, or other Nkx genes, contributes to regulating differentiated hypothalamic functions is not known. We now report that postnatal hypothalamic TTF-1 expression is developmentally regulated and associated with the neuroendocrine process of female sexual development. Lesions of the hypothalamus that cause sexual precocity transiently activate neuronal TTF-1 expression near the lesion site. In intact animals, hypothalamic TTF-1 mRNA content also increases transiently, preceding the initiation of puberty. Postnatal expression of the TTF-1 gene was limited to subsets of hypothalamic neurons, including LHRH neurons, which control sexual maturation, and preproenkephalinergic neurons of the lateroventromedial nucleus of the basal hypothalamus, which restrain sexual maturation and facilitate reproductive behavior. TTF-1 mRNA was also detected in astrocytes of the median eminence and ependymal/subependymal cells of the third ventricle, where it colocalized with erbB-2, a receptor involved in facilitating sexual development. TTF-1 binds to and transactivates the erbB-2 and LHRH promoters, but represses transcription of the preproenkephalin gene. The singular increase in hypothalamic TTF-1 gene expression that precedes the initiation of puberty, its highly specific pattern of cellular expression, and its transcriptional actions on genes directly involved in neuroendocrine reproductive regulation suggest that TTF-1 may represent one of the controlling factors that set in motion early events underlying the central activation of mammalian puberty.

Effect of enrofloxacin-Na against pathogens related to the respiratory and alimentary diseases in suckling and weanling piglets

A field trial was conducted to evaluate effect of enrofloxacin-Na against pathogens related to the respiratory and alimentary diseases in eighty suckling piglets (6-7 days old) and eighty weanling piglets (5-6 weeks old). Respective twenty of the suckling and weanling piglets were assigned to each of 4 experimental groups; control (non-treated), clinical injection dose (CID), 2x clinical injection dose (2CID). and premix. A 0.05 ml (2.5 mg) of enrofloxacin-Na injection (5% solution, 1 ml) per kg body weight of piglets as CID was injected intramuscularly for 3 days and the clinical signs were observed for 9 days. The premix (150 ppm) of enrofloxacin-Na was administered with feed for 7 days ad libitum and the clinical signs were observed for 13 days. The enrofloxacin-Na-treated piglets showed a higher increase in body weight and a lower feed per gain than the control piglets. In addition, the treatment of enrofloxacin-Na, regardless of the route of administration, decreased the incidence rate of diarrhea in suckling piglets and respiratory symptoms in weanling piglets. The isolation index of E. coli and Cl. perfringens during the treatment periods was also lowered by the enrofloxacin-Na treatment in both suckling and weanling piglets. The antibiotics was also evaluated as safe locally and whole bodily as treated by injection or feeding. These results indicate that the newly developed antibiotics, enrofloxacin-Na, is very useful for the prevention and therapy of swine diseases in the pig industry.

Survival and stability of bifidobacteria loaded in alginate poly-l-lysine microparticles

Bifidobacteria-loaded alginate microparticles were prepared by spraying a mixture of alginate and bifidobacteria culture using an air atomization method. Survival and stability of bifidobacteria loaded in microparticles were then evaluated. Survival of bifidobacteria from alginate poly-l-lysine microparticles was significantly increased when MRS broth or yeast extract was added in simulated intestinal fluid (pH 6.8). The number of bifidobacteria gradually increased for 8 h (10(8) cfu/g) and then reached about 10(9)-10(10) cfu/g when incubated over 12 h in intestinal fluid containing 0.5% yeast extract and 0.05% L-cysteine. The survival of bifidobacteria was highly dependent on the pH of the exposing media. When the bifidobacteria was immobilized with alginate or even poly-l-lysine treatment, the survival of bifidobacteria was highly enhanced in the low pH conditions (ca. > 10(8) vs. < 10(3) cfu/g). The stability of free flowing bifidobacteria-loaded alginate poly-l-lysine microparticles was significantly improved during storage at 4 degrees C in a refrigerator when compared to bifidobacteria cultures. The bifidobacteria-loaded alginate poly-l-lysine microparticles could be applied to various dairy products.

Structural understanding of the allosteric conformational change of cyclic AMP receptor protein by cyclic AMP binding

Cyclic AMP receptor protein (CRP) plays a key role in the regulation of more than 150 genes. CRP is allosterically activated by cyclic AMP and binds to specific DNA sites. A structural understanding of this allosteric conformational change, which is essential for its function, is still lacking because the structure of apo-CRP has not been solved. Therefore, we performed various NMR experiments to obtain apo-CRP structural data. The secondary structure of apo-CRP was determined by analyses of the NOE connectivities, the amide proton exchange rates, and the (1)H-(15)N steady-state NOE values. A combination of the CSI-method and TALOS prediction was also used to supplement the determination of the secondary structure of apo-CRP. This secondary structure of apo-CRP was compared with the known structure of cyclic AMP-bound CRP. The results suggest that the allosteric conformational change of CRP caused by cyclic AMP binding involves subunit realignment and domain rearrangement, resulting in the exposure of helix F onto the surface of the protein. Additionally, the results of the one-dimensional [(13)C]carbonyl NMR experiments show that the conformational change of CRP caused by the binding of cyclic GMP, an analogue of cyclic AMP, is different from that caused by cyclic AMP binding.

Structure-expression relationships of the 15-kDa selenoprotein gene. Possible role of the protein in cancer etiology

Selenium has been implicated in cancer prevention, but the mechanism and possible involvement of selenoproteins in this process are not understood. To elucidate whether the 15-kDa selenoprotein may play a role in cancer etiology, the complete sequence of the human 15-kDa protein gene was determined, and various characteristics associated with expression of the protein were examined in normal and malignant cells and tissues. The 51-kilobase pair gene for the 15-kDa selenoprotein consisted of five exons and four introns and was localized on chromosome 1p31, a genetic locus commonly mutated or deleted in human cancers. Two stem-loop structures resembling selenocysteine insertion sequence elements were identified in the 3'-untranslated region of the gene, and only one of these was functional. Two alleles in the human 15-kDa protein gene were identified that differed by two single nucleotide polymorphic sites that occurred within the selenocysteine insertion sequence-like structures. These 3'-untranslated region polymorphisms resulted in changes in selenocysteine incorporation into protein and responded differently to selenium supplementation. Human and mouse 15-kDa selenoprotein genes manifested the highest level of expression in prostate, liver, kidney, testis, and brain, and the level of the selenoprotein was reduced substantially in a malignant prostate cell line and in hepatocarcinoma. The expression pattern of the 15-kDa protein in normal and malignant tissues, the occurrence of polymorphisms associated with protein expression, the role of selenium in differential regulation of polymorphisms, and the chromosomal location of the gene may be relevant to a role of this protein in cancer.

Solution structure and membrane-binding property of the N-terminal tail domain of human annexin I

The conformational preferences of AnxI(N26), a peptide corresponding to residues 2-26 of human annexin I, were investigated using CD and NMR spectroscopy. CD results showed that AnxI(N26) adopts a mainly alpha-helical conformation in membrane-mimetic environments, TFE/water and SDS micelles, while a predominantly random structure with slight helical propensity in aqueous buffer. The helical region of AnxI(N26) showed a nearly identical conformation between in TFE/water and in SDS micelles, except for the orientation of the Trp-12 side-chain, which was quite different between the two. The N-terminal region of the AnxI(N26) helix showed a typical amphipathic nature, which could be stabilized by the neighboring hydrophobic cluster. The helical stability of the peptide in SDS micelles was increased by addition of calcium ions. These results suggest that the N-terminal tail domain of human annexin I interacts with biological membranes in a partially calcium-dependent manner.

Identification of alternative splicing and negative splicing activity of a nonsegmented negative-strand RNA virus, Borna disease virus

Borna disease virus (BDV) is a nonsegmented negative-strand RNA virus that belongs to the Mononegavirales. Unlike other animal viruses of this order, BDV replicates and transcribes in the nucleus of infected cells. Previous studies have shown that BDV uses RNA splicing machinery for its mRNA expression. In the present study, we identified spliced RNAs that use an alternative 3' splice site, SA3, in BDV-infected cell lines as well as infected animal brain cells. Transient transfection analysis of cDNA clones of BDV RNA revealed that although SA3 is a favorable splice site in mammalian cells, utilization of SA3 is negatively regulated in infected cells. This negative splicing activity of the SA3 site is regulated by a putative cis-acting region, the exon splicing suppressor (ESS), within the polymerase exon of BDV. The BDV ESS contains similar motifs to other known ESSs present in viral and cellular genes. Furthermore, our results indicated that a functional polyadenylation signal just upstream of the BDV ESS is also involved in the regulation of alternative splicing of BDV. These observations represent the first documentation of complex RNA splicing in animal RNA viruses and also provide new insight into the mechanism of regulation of alternative splicing in animal viruses.

Identification of the gene encoding BmpB, a 30 kDa outer envelope lipoprotein of Brachyspira (Serpulina) hyodysenteriae, and immunogenicity of recombinant BmpB in mice and pigs

A gene encoding a 30kDa outer envelope protein of the intestinal spirochaete Brachyspira (Serpulina) hyodysenteriae, was cloned and expressed in Escherichia coli strain XLOLR. Five phagemids containing DNA inserts encoding the protein were established and one clone (pSHA) was sequenced. An 816bp hypothetical open reading frame (ORF) was identified, with a potential ribosome binding site (AGGAG), and putative -10 (TATAAT) and -35 (TTGAAA) promoter regions upstream from the ATG start of the ORF. A 12bp inverted repeat sequence, possibly serving as a transcription terminator, was identified downstream from the TAA stop codon. Analysis of the amino acid sequence identified a 19 residue hydrophobic signal peptide, incorporating a potential signal peptidase cleavage site and membrane lipoprotein lipid attachment site. Further analysis of the amino acid usage of this lipoprotein, designated BmpB, showed its possible outer membrane localisation. Comparison of the gene encoding the lipoprotein, bmpB, with GenBank nucleotide sequences showed that it has homology with the gene (plp3) encoding Plp3, an outer membrane lipoprotein of Pasteurella haemolytica (54% identity in 735bp). Comparison of the deduced amino acid sequence with the SWISS-PROT amino acid database revealed greatest homology with the outer membrane lipoproteins (Plp1, 2, 3) of P. haemolytica (34% identity in 242 aa, 37% identity in 250 aa, and 39% identity in 272 aa, respectively), and lipoproteins (rcsF and lipoprotein-28) of E. coli (40% identity in 267 aa and 36% identity in 263 aa, respectively). Three of the recombinant E. coli clones (pSHA, pSHD, and pSHE) were formalinised and used to immunise mice. A bacterin preparation of one recombinant E. coli clone (pSHA) was used to immunise pigs. Sera from these mice and pigs recognised the 30kDa lipoprotein in outer membrane preparations of B. hyodysenteriae, indicating the immunogenicity of recombinant BmpB. Sera from pigs naturally infected with B. hyodysenteriae also reacted with recombinant BmpB expressed in E. coli.