A spore coat protein, CotS, of Bacillus subtilis is synthesized under the regulation of sigmaK and GerE during development and is located in the inner coat layer of spores

The spore coat of Bacillus subtilis has a unique morphology and consists of polypeptides of different sizes, whose synthesis and assembly are precisely regulated by a cascade of transcription factors and regulatory proteins. We examined the factors that regulate cotS gene expression and CotS assembly into the coat layer of B. subtilis by Northern blot and Western blot analysis. Transcription of cotS mRNA was not detected in sporulating cells of sigmaK and gerE mutants by Northern blot analysis. By Western blot analysis using anti-CotS antibody, CotS was first detected in protein samples solubilized from wild-type cells at 5 h after the start of sporulation. CotS was not detected in the vegetative cells and spores of a gerE mutant or in the spores of mutants deficient in sigmaE, sigmaF, sigmaG, or sigmaK. CotS was detected in the sporangium but not in the spores of a cotE mutant. The sequence of the promoter region of cotS was similar to the consensus sequences for binding of sigmaK and GerE. These results demonstrate that sigmaK and GerE are required for cotS expression and that CotE is essential for the assembly of CotS in the coat. Immunoelectron microscopic observation using anti-CotS antibody revealed that CotS is located within the spore coat, in particular in the inner coats of dormant spores.

Prevention of cerebral vasospasm by vasodilatory peptide maxadilan following subarachnoid hemorrhage in rabbits

Maxadilan is a vasodilatory peptide isolated from the blood-feeding sand fly Lutzomyia longipalpis. Its vasodilatory activity, estimated by the formation of erythema on rabbit skin, is greater than those of calcitonin gene-related peptide, vasoactive intestinal polypeptide and pituitary adenylyl cyclase activating polypeptide (PACAP). We have recently demonstrated that maxadilan is a specific agonist for the PACAP type I receptor, which is widely distributed in brain. Therefore, we were interested in the vasodilatory effect of maxadilan on cerebral arteries and the possibility of its clinical use for the delayed cerebral vasospasm following subarachnoid (SAH). In the first experiment, 10(-10) mol/kg of maxadilan (in sterile water) was injected into the cisterna magna three days after the induction of experimental SAH in rabbits (n = 6). Maxadilan dilated spastic basilar arteries within 30 min of the injection, but not at 6 h. In the second experiment, to prolong the vasodilatory effect of maxadilan, tablets containing stearic acid, hydrogenated oil, lactose, hydroxypropylcellulose and 15 mg of maxadilan were prepared. In vitro testing showed that 60% of maxadilan could be released slowly within the initial five days. In vivo experiments were performed to implant the maxadilan tablet (n = 7) and the placebo tablet (n = 6) into the cisterna magna after the induction of experimental SAH in rabbits. The spastic response of the basilar artery was maximum on day three in the placebo-treated groups. In contrast, we observed no significant change in the arterial diameter until day five in the rabbits treated with maxadilan tablet. These data suggest that maxadilan may have therapeutic potency in treating cerebral vasospasm.

Prostate cancer metastasis-suppressor genes: a current perspective

Prostate cancers account for 43% of all cancers diagnosed in American men. It is estimated that in 1996, 317,000 new cases of prostate cancer were diagnosed and 41,000 men died of the disease. The challenge of treating prostate cancer lies in accurately distinguishing those histologically-localized cancers which will complete metastatic progression from those that will remain indolent. At this time, we lack appropriate histological markers to make such distinctions, therefore, it is often difficult to accurately predict the clinical course of an individual patient's disease. There is growing evidence that a critical event in the progression of a tumor cell from a non-metastatic to metastatic phenotype is the loss of function of metastasis-suppressor genes. These genes specifically suppress the ability of a cell to metastasize. Work from several groups has demonstrated that human chromosomes 8, 10, 11 and 17 encode prostate cancer metastasis suppressor activities. As a result of these efforts the first prostate cancer metastasis-suppressor gene, KAI1, was identified and mapped to the p11-2 region of chromosome 11. In subsequent studies, an additional gene encoded by the same region, CD44 was also determined to have metastasis-suppressor activity. Recent studies have shown a correlation between decreased expression of KAI1 and CD44 and an increased malignant potential of prostate cancers. It is anticipated that the identification of other metastasis suppressor genes may allow for the development of diagnostic markers useful in the clinical substaging of individual tumors. This manuscript is intended to present our perspective on the importance of these genes in the understanding of prostate cancer progression. More importantly, we present new findings from our laboratory's effort to identify the metastasis-suppressor genes encoded by human chromosome 17. Specifically we report the strategy currently being used to evaluate a series of candidate genes and the approach being utilized to pinpoint the metastasis-suppressor region on human chromosome 17.

Adenovirus-mediated transduction with human glial cell line-derived neurotrophic factor gene prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopamine depletion in striatum of mouse brain

As a novel trial of neuroprotective therapy of neurodegenerative diseases, we have constructed a recombinant adenovirus vector (rAdv) bearing a neurotrophic factor gene to deliver the factor to rescue neurons in vivo. In the present study, human glial cell line-derived neurotrophic factor (hGDNF) was chosen to examine the applicability of our strategy to a mouse model of Parkinson's disease. During the construction of the rAdv, we found that the strong constitutive hGDNF expression unit somehow inhibited the appearance of the rAdv. Therefore we adopted a self-contained tetracycline-regulated expression system to acquire an rAdv expressing hGDNF. By analyzing the condition medium of SH-SY5Y cells infected with our constructed virus vector, we confirmed that biologically active GDNF was successfully expressed in vitro. For an animal study, we delivered this virus vector directly to the C57 black mouse brain and then exposed the animal to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to injure the nigrostriatal dopaminergic neurons. One week after the MPTP exposure, the neuroprotective effect of the virus vector was estimated by measurement of the dopamine content in the striatum of the mouse brain. The mice that had received our constructed virus had significantly higher dopamine levels in their striatum, demonstrating that our rAdv expressing hGDNF has therapeutic potential to protect the nigrostriatal dopaminergic neurons in vivo.

A survey of Salmonella enteritidis in spent hens and its relation to farming style in Hokkaido, Japan

In order to estimate the distribution of Salmonella including Salmonella enteritidis (SE) and SE-antibodies in commercial layer hen flocks in Hokkaido, the northern prefecture of Japan, a survey of spent layer hens was performed, from August 1996 to January 1997. From the three spent hen processing plants, samples of intestines and sera were collected from 740 birds presented for slaughter from 37 flocks of 22 layer hen farms. Intestines from each birds were cultured for Salmonella including Salmonella enteritidis. Serum from each bird was examined for SE-antibody with the enzyme-linked immunosorbent assay (ELISA). Salmonella (any serotype) and Salmonella enteritidis were isolated from 50 (6.8%) and three (0.4%) of 740 birds, respectively, and SE-antibody positive values were recorded from seven birds (0.9%). SE-antibody positive birds did not always indicate isolation of Salmonella enteritidis, however SE-antibody positive hens were demonstrated only from Salmonella enteritidis positive flocks. Salmonellae were isolated from the birds of ten layer hen farms, all of these hens were raised in houses without windows and with automatic feeders. No isolations of salmonella were made from birds raised in houses with windows. From the windowless houses, Salmonellae were isolated from 46 (21.8%) of 260 birds in houses with four to six cages piled up vertically, and from six (2.5%) of 240 samples from the houses with four to five cages piled in a slanting manner.

Identification of a region required for binding to presecretory protein in Bacillus subtilis Ffh, a homologue of the 54-kDa subunit of mammalian signal recognition particle

Bacillus subtilis Ffh protein is a homologue of the 54-kDa subunit of mammalian signal recognition particle (SRP54). It contains three highly hydrophobic regions (h1, h2, and h3) in the C-terminal methionine-rich domain (M-domain). Two of the hydrophobic regions, h2 and h3, are essential for small cytoplasmic RNA (scRNA) binding [Kurita, K., Honda, K., Suzuma, S., Takamatsu, H., Nakamura, K., & Yamane, K. (1996) J. Biol. Chem. 271, 13,140-13,146]. Using purified presecretory proteins and mutant Ffh proteins, we identified a region required for presecretory protein binding in B. subtilis Ffh. Deletion of this region, which consisted of residues Ser311-Gly362 of B. subtilis Ffh, including a hydrophobic sequence (h1), reduced precursor binding activity. In contrast, deletions of residues Leu121-Lys279, Lys364-Met446, or Leu338-Ser397 of B. subtilis Ffh did not. We also analyzed the mutant B. subtilis Ffh proteins, FfhQQQR and FfhQQQQ having wild-type residues 398-401 (Arg-Arg-Lys-Arg) replaced with Gln3Arg and Gln4, respectively. FfhQQQR bound to both scRNA and presecretory protein. Although the FfhQQQQ mutation prevented binding to scRNA, binding to the precursor was not affected. FfhQQQR restored the growth of B. subtilis DF46 strain in which ffh gene expression is regulated by an inducible promoter in the absence of an inducer, whereas FfhQQQQ did not. These results indicate that the region including h1 is required for B. subtilis Ffh to bind to presecretory protein. The results also suggest that scRNA is required for the complete function of the B. subtilis SRP-like particle in vivo, although this protein is intrinsically capable of binding a signal peptide free from scRNA.

Enhancing effect of nonionic surfactant on the inactivation of lipopolysaccharide by steam-heat treatment II

n-alkylpolyoxyethylene surfactants (CnH2n+1O(CH2CH2O)mH; CnEm) showed a strong enhancing effect on the inactivation of lipopolysaccharide (LPS) by heat treatment over a wide range of temperatures. The effect of CnE8 (n = 10-16) was observed above the critical micelle concentration (CMC) and above the cloud point, and was influenced by the length of the alkyl chains. The efficacy of the surfactants was in the order C10E8 < C12E8, C16E8 < C14E8. However, the hydrophilic moiety seemed to have no influence. An 80-95% solution of n-butanol showed a similar effect, indicating that LPS was more effectively inactivated in the oily phase of the surfactants than in water. The effect of surfactant on the hydrodynamic diameter of LPS was the same before and after steam-heat treatment for 20 minutes at 121 degrees C. Each surfactant disaggregated LPS without alteration of the activity of LPS before the heat treatment. We consider that the surfactants interact with LPS in the region of lipid A in a manner that favors loss of the activities of LPS during heating.

Detection of p53 gene mutations in fine-needle aspiration biopsied breast cancer specimens: correlations with nuclear p53 accumulations and tumor DNA aneuploidy patterns

Using the polymerase chain reaction and a single strand conformation polymorphism (PCR-SSCP) analysis, p53 gene mutations have been examined preoperatively in aspirated biopsy specimens from 22 breast cancers. In eight (36%) of the studied cases, abnormal bands indicating mutations were detected and were more frequently present in common invasive breast carcinomas. Eight of the breast cancer cases were found to be positive for mutations: direct DNA sequencing confirmed eight mutations and revealed G to A and A to G nucleotide changes in five (63%) and two (25%) cases, respectively. The mutations that were localized at the CpG site of the gene were seen in three cases. Additionally, an immunohistochemical investigation of the presence of the p53 protein and a DNA flow-cytometrical analysis of the 22 resected breast cancers were also performed. Nuclear p53 protein accumulations and a DNA aneuploidy pattern were detected in 11 (50%) cases and in 16 (73%) cases, respectively, and both significantly correlated with p53 gene mutations (P < 0.01 and P < 0.001, respectively; Fisher's exact test). In contrast, in five cases of a breast cancer with a lower histologic grade, no p53 gene mutations, nuclear p53 protein accumulations, or DNA aneuploidy patterns were detected. These results thus suggest that p53 gene mutations, nuclear accumulations of the p53 protein, and a DNA aneuploidy pattern are events that occur with close relationship in the progression of a breast cancer, and that p53 abnormalities appear to correlate with a high grade of the malignancy. Therefore, the detection of p53 gene mutations in aspirated biopsy specimens of breast cancers may be helpful for an accurate and rapid cytological diagnosis, which reflects the prognosis.

Sequence and functional analysis of the 5'-flanking region of the mouse growth inhibitory factor gene

1. The growth inhibitory factor (GIF) is a 68-amino acid protein which is capable of inhibiting the growth of neuronal cells in vitro. 2. We have cloned and sequenced the 5'-flanking region of the mouse GIF gene, which spans from the transcriptional initiation site to the -1854 nucleotide. 3. This region contains sequences homologous to hgcs, SPE, and the JCV silencer domain that functions in a glial cell specific manner. This region also contains two metal responding elements and putative binding sites for AP-1, AP-2, Sp-1, SP-2, NF-1, and CREB. 4. An analysis of the reporter plasmids containing the various regions of the 5'-flanking sequence revealed that the region indeed functioned in a tissue-specific manner in glial cells and that the region between -328 and 175 is responsible for suppression, while the region between -175 and -49 is involved in the activation of gene expression.

Adenovirus-mediated gene transfer and expression of human beta-glucuronidase gene in the liver, spleen, and central nervous system in mucopolysaccharidosis type VII mice

Mucopolysaccharidosis type VII (Sly syndrome) is a lysosomal storage disease caused by inherited deficiency of the lysosomal enzyme beta-glucuronidase. A murine model of this disorder has been well characterized and used to study a number of forms of experimental therapies, including gene therapy. We produced recombinant adenovirus that expresses human beta-glucuronidase and administered this recombinant adenovirus to beta-glucuronidase-deficient mice intravenously. The beta-glucuronidase activities in liver and spleen were elevated to 40% and 20%, respectively, of the heterozygote enzymatic level at day 16. Expression persisted for at least 35 days. Pathological abnormalities of these tissues were also improved, and the elevated levels of urinary glycosaminoglycans were reduced in treated mice. However, the beta-glucuronidase activity in kidney and brain was not significantly increased. After administration of the recombinant adenovirus directly into the lateral ventricles of mutant mice, the beta-glucuronidase activity in crude brain homogenates increased to 30% of heterozygote activity. Histochemical demonstration of beta-glucuronidase activity in brain revealed that the enzymatic activity was mainly in ependymal cells and choroid. However, in some regions, the adenovirus-mediated gene expression was also evident in brain parenchyma associated with vessels and in the meninges. These results suggest that adenovirus-mediated gene delivery might improve the central nervous system pathology of mucopolysaccharidosis in addition to correcting visceral pathology.

A case of renal amyloidosis associated with hepatic adenoma: the pathogenetic role of tumor necrosis factor-alpha

We report a case of a 35-year-old man with secondary amyloidosis chiefly involving the kidney and heart. The patient showed severe proteinuria and ischemic heart damage and had hepatic adenoma at the age of 33. Biopsy specimens from the kidney, heart, stomach and rectum showed extensive deposition of amyloid. After the surgical resection of a 300-gram hepatic adenoma, highly elevated c-reactive protein (CRP) levels decreased and the serum amyloid A (SAA) level was completely normalized. Normal liver cells were immunostained with rabbit anti-SAA antibody, but the cells in adenoma tissue and kidney were not. Electron microscopic examination revealed extracellular deposition of amyloid fibrils in the hepatic adenoma and kidney tissue. The concentration of tumor necrosis factor-alpha (TNF-alpha) (312 pg/mg tissue protein) was 7-fold higher in adenoma tissue than in normal liver tissue. Moreover, SAA (2.8 ng/mg tissue protein) was 2-fold higher in normal liver tissue than in adenoma tissue. Since TNF-alpha has been known to induce SAA production in target cells, the present results suggest that the hepatic adenoma produced TNF-alpha, which then caused mainly secondary amyloidosis in the kidney and heart. Currently, 2 years after surgical resection, urinary excretion of protein has been markedly reduced (from 3.5 to 0.8 g/day) and renal and cardiac functions are normal without specific medical treatment.

Mechanism of stereospecific conversion of DL-5-substituted hydantoins to the corresponding L-amino acids by Pseudomonas sp. strain NS671

The mechanism of stereospecific conversion of DL-5-substituted hydantoins to the corresponding L-amino acids by Pseudomonas sp. strain NS671 was studied. The results indicated that the hydantoinase catalyzed the hydrolysis reaction of both D- and L-5-(2-methylthioethyl)hydantoin, and that the hydrolysis of the L-enantiomer proceeded preferentially compared with that of the D-enantiomer. On the basis of these findings, the mechanism was speculated to be as follows: DL-5-substituted hydantoins are converted exclusively to the L-forms of the corresponding N-carbamyl-amino acids by the hydantoinase in combination with hydantoin racemase. The N-carbamyl-L-amino acids are then converted to L-amino acids by N-carbamyl-L-amino acid amidohydrolase.

A synthetic form of tracheal antimicrobial peptide has both bactericidal and antifungal activities

We have chemically synthesized tracheal antimicrobial peptide (TAP) with 38 amino acids and examined efficacy of the peptide on various organisms. The synthetic peptide showed potent bactericidal effect on both gram positive and negative bacteria. The action of bactericidal effect was relatively quick and 99.9% of E. coli cells were killed within 90 minutes at a concentration of 2.5 micrograms/ml of TAP. The peptide also showed antifungal activity against both mycelia (Aspergillus fumigatus) and yeast (Candida albicans) forms of fungi. Our domain analysis with a series of synthetic peptides of various lengths indicates that 17 amino acid residues of the C-terminal end is the minimum functional domain of the bactericidal activity.

Prevention of cerebral vasospasm by calcitonin gene-related peptide slow-release tablet after subarachnoid hemorrhage in monkeys

OBJECTIVE

The goal of this work was to investigate the efficacy of a calcitonin gene-related peptide (CGRP) slow-release tablet (CGRP tablet) for the prevention of cerebral vasospasm after subarachnoid hemorrhage (SAH).

METHODS

Experimental SAH was produced in 10 cynomolgus monkeys by placing a clot around the internal carotid artery bifurcation (Day 0). In five animals, CGRP tablets (1200 micrograms of CGRP) were then placed in the cerebrospinal fluid space (CGRP group). In two animals, placebo tablets were similarly placed (placebo group). The remaining three animals were treated with no tablets after SAH (SAH group). A series of angiographic analyses were performed, before SAH and on Days 7 and 14, to examine changes in the diameters of the ipsilateral internal carotid artery, middle cerebral artery, and anterior cerebral artery. The CGRP concentration in the cerebrospinal fluid taken before each angiogram was also determined.

RESULTS

In the SAH and placebo groups, cerebral vasospasm developed on Day 7 (54.8% of the pre-SAH value at the internal carotid artery, 62.3% at the middle cerebral artery, 51.3% at the anterior cerebral artery, and 56.1% as an average of the three arteries). In the CGRP group, vasospasm was significantly ameliorated at the middle cerebral artery, at the anterior cerebral artery, and on average (81.7, 81.1, and 75.7%, P < 0.05, 0.03, and 0.02, respectively). The CGRP concentration was positive only on Day 7 for the CGRP group (6.5 nmol/L).

CONCLUSION

The CGRP tablet prevented cerebral vasospasm after SAH and may have significant potential for the treatment of patients with SAH.

Enhancing effect of non-ionic surfactant on the inactivation of lipopolysaccharide by steam-heat treatment I

Polyoxyethylene (20) sorbitan mono-fatty acid esters strongly enhanced the inactivation of lipopolysaccharide (LPS) by steam-heat treatment at 121 degrees C, as assayed by using the Limulus amebocyte lysate (LAL) and the pyrogen test. In an aqueous solution containing 0.1% surfactant, the decrease of LPS (1 microgram/ml) from E. coli 055:B5 at 121 degrees C followed first-order kinetics. Based on the LAL assay, 0.1% surfactant was essential to achieve 3-log cycle reduction of LPS with concomitant loss of pyrogenicity by steam-heat treatment for 20 min at 121 degrees C. Steam-heat treatment for 20 min at 121 degrees C in the absence of surfactant was insufficient to achieve depyrogenation. Polyoxyethylene (9) lauryl ether and decaglycerin mono-laurate similarly enhanced depyrogenation by steam-heat treatment. The effects of all the surfactants were concentration-dependent for all of the six kinds of LPS examined.

Quantitative evaluation of the gastrointestinal absorption of protein into the blood and lymph circulation

In order to investigate the fate of orally administered proteins, the absorption of ovalbumin (OVA) from the gastrointestinal tract into both the blood and lymph circulation was quantitatively evaluated. After oral administration, a significant amount of intact OVA was detected in both the plasma and the lymph fluid by means of a two-site enzyme immunoassay. The extent of absorption into the plasma, calculated from the area under the plasma concentration versus time curve of OVA after oral and intravenous administration, was only 0.007-0.008% of the dose. This value is extremely low compared to that after nasal administration, showing the stronger barrier function of the gastrointestinal tract against the invasion of macromolecular proteins into the body. The extent of absorption into the lymph was dose-dependent (0.0007-0.002% of dose), and a higher dose leads to a higher fraction of OVA absorbed into the lymph. Moreover, it was demonstrated that not only the small intestine but also the stomach can absorb OVA. OVA absorbed from the stomach was transferred almost exclusively to the blood circulation, which suggests different mechanisms and/or routes of absorption between the stomach and the small intestine. In order to improve the low oral absorption, OVA was incorporated in liposomes and administered orally. Although the effect of liposomes was not significant, it increased OVA absorption into both the plasma and lymph by about 2 to 3-fold. It was considered that the liposomes suppressed the enzymatic degradation of OVA and released it slowly in the gastrointestinal tract.

Effects of bromocriptine and/or L-DOPA on neurons in substantia nigra of MPTP-treated C57BL/6 mice

The effects of bromocriptine and/or L-DOPA on substantia nigra neurons of MPTP-intoxicated mice were investigated. L-DOPA reduced the number of neurons. Bromocriptine protected the neurons from damage by L-DOPA but had no effect on the neurons damaged by MPTP. The treatment of bromocriptine and L-DOPA protected the neurons compared with single administration of bromocriptine. It seems reasonable to suppose that bromocriptine should be added to L-DOPA in order to protect the neurons in parkinsonism.

Antimicrobial activity of a 13 amino acid tryptophan-rich peptide derived from a putative porcine precursor protein of a novel family of antibacterial peptides

It has long been speculated that porcine cathelin is an N-terminal fragment of a longer precursor protein which possesses antimicrobial activity. In an attempt to find such a precursor, a cDNA clone was recently isolated and sequenced by screening a cDNA library from porcine bone marrow. In order to identify the functional activity of the putative protein encoded by an open reading frame, we have synthesized various lengths of peptides that correspond to the C-terminal region of the protein and examined them for their antimicrobial activities. We found that a 13 amino acid tryptophan-rich region with the sequence of VRRFPWWWPFLRR had strong antimicrobial activity with a wide spectrum. It showed potency against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus epidermidis, Proteus mirabilis, and Streptococcus group D as well as Aspergillus fumigatus. The action of this peptide is bactericidal rather than bacteriostatic and this activity is completely inhibited by 2 mM MgCl2. Our results indicate that the previously identified putative precursor encoded by the isolated cDNA indeed possesses a potent antimicrobial activity and that this 13 amino acid synthetic peptide is considered to be a potentially effective drug against various infectious agents.

Gene therapy for metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is an inherited metabolic disease which is characterized by a deficiency of arylsulfatase A (ASA). This deficiency causes progressive accumulation of cerebroside sulfate in oligodendrocytes (OL) in the brain, resulting in dysmyelination. Approaches being developed by the authors to treating MLD are based on direct delivery of ASA genes into the brain. In the present report, it has been shown that the recombinant adenovirus (Adex1SRLacZ) was able to transduce the OL very efficiently. Moreover, primary fibroblasts from MLD patients were exposed to recombinant adenovirus expressing the ASA gene (Adex1SRASA) and the cells expressed the transgene. The influence of overexpression of ASA on the activity of other sulfatases was also tested in fibroblasts from patients with MLD using a retrovirus vector (MFG-ASA). It was demonstrated that the overexpression of ASA reduces the activity of various sulfatases by a small amount but does not induce an accumulation of glycosaminoglycan. These results indicate that the influence of ASA overexpression on other sulfatases is different from that of the N-acetygalactosamine-4-sulfatase overexpression in a previous report. It was concluded that the correction of ASA deficiency by a recombinant adenovirus that potentially could be used to transfer the gene to the brain, and gene therapy for MLD based on gene transfer of the ASA gene to mutant cells will be feasible because the overexpression of ASA in cells does not lead to profound deficiency of other sulfatases or result in a new phenotype.

N-carbamyl-L-amino acid amidohydrolase of Pseudomonas sp. strain NS671: purification and some properties of the enzyme expressed in Escherichia coli

An N-carbamyl-L-amino acid amidohydrolase was purified from cells of Escherichia coli in which the gene for N-carbamyl-L-amino acid amidohydrolase of Pseudomonas sp. strain NS671 was expressed. The purified enzyme was homogeneous by the criterion of SDS-polyacrylamide gel electrophoresis. The results of gel filtration chromatography and SDS-polyacrylamide gel electrophoresis suggested that the enzyme was a dimeric protein with 45-kDa identical subunits. The enzyme required Mn2+ ion (above 1 mM) for the activity. The optimal pH and temperature were 7.5 and around 40 degrees C, respectively, with N-carbamyl-L-methionine as the substrate. The enzyme activity was inhibited by ATP and was lost completely with p-chloromercuribenzoate (1 mM). The enzyme was strictly L-specific and showed a broad substrate specificity for N-carbamyl-l-alpha-amino acids.

Effect of steam-heat treatment with/without divalent cations on the inactivation of lipopolysaccharides from several bacterial species

The inactivation of endotoxin from six species of smooth gram-negative bacteria (S-form) by steam-heat treatment was investigated using the Limulus amebocyte lysate (LAL) assay. Biphasic decreases of endotoxins from four species of bacteria were observed upon steam-heat treatment of 1 microgram/ml endotoxin solution at 121 degrees C in a steam sterilizer. A lag time, however, was observed in the inactivation profiles of V. cholerae and P. aeruginosa. Distinct differences in heat resistance were observed among the bacterial species. The decrease rate was found to be concentration-dependent, and endotoxins at low concentrations (less than 10 ng/ml) were inactivated by the treatment to below the detection limit of the LAL assay. The time-course of the decrease of endotoxin from rough strains (R-form) resembled that of the respective S-form. The inactivation of R-form, especially Rc mutant, endotoxin was markedly affected by divalent cations such as Mg2+ and Ca2+, which appear to promote reaggregation of the endotoxin.

Effects of synthetic form of tracheal antimicrobial peptide on respiratory pathogens

We have synthesized a C-terminal portion of tracheal antimicrobial peptide (TAP) with 38 amino acids and tested it for efficacy on various clinical isolates of Pseudomonas aeruginosa strains from patients with cystic fibrosis and also on Aspergillus fumigatus. Our results indicate that the synthetic TAP has both potent bactericidal and fungicidal activities and that a combination of TAP and amphotericin B showed strong additive effects of growth inhibition on A fumigatus. These results suggest that TAP is potentially an effective therapy for Aspergillus and multi-drug-resistant Pseudomonas, pathogens that are often a serious threat to patients with cystic fibrosis.

Analysis of plasma metabolites during human PET-studies with three receptor ligands, [11C]YM-09151-2, [11C]doxepin and [11C]pyrilamine

Carbon-11 labeled metabolites in human plasma were analyzed by high-performance liquid chromatography during positron emission tomography (PET) studies using the dopamine D2 ligand [11C]YM-09151-2 as well as the histamine H1 ligands [11C]doxepin and [11C]pyrilamine. For all the three tracers, blood clearance of the radioactivity was extremely rapid after an i.v. injection. The plasma protein-binding of [11C]YM-09151-2 and [11C]doxepin had protective effects upon the metabolic alteration of the ligands, whereas [11C]pyrilamine was free from the protein-binding and immediately degraded. The degradation of [11C]doxepin was more rapid in epileptic patients on medication than in normal subjects. These results indicate that analysis of metabolites in the plasma is necessary to determine the accurate arterial input function for quantitative PET measurement.

A noncompetitive enzyme immunoassay (hetero-two-site enzyme immunoassay) for salmon calcitonin: determination of the bioavailability of subcutaneous salmon calcitonin and its correlation with the hypocalcemic activity in rats

A noncompetitive enzyme immunoassay method (hetero-two-site enzyme immunoassay) for salmon calcitonin (SCT) and its usability for the pharmacokinetic study are described. The method in brief proceeds as follows: centrifugal filtration through a polysaccharide membrane to remove plasma proteins, biotinylation, trapping onto an anti-SCT IgG-coated polystyrene ball, acid elution, coupling with affinity-purified anti-SCT Fab'-peroxidase conjugate, final trapping onto streptavidin-coated polystyrene balls, and measurement of peroxidase activity bound to the balls by fluorometry. The practical detection limit of SCT was 0.1 pg (30 amol)/assay and 2 pg/ml as the assay sample's concentration, which was at least fivefold lower than those previously reported by competitive radioimmunoassays. The application of this method has enabled us to 1) directly estimate the bioavailability of SCT dosed subcutaneously at the therapeutic levels (1.2 and 4.7 micrograms/kg) for its antiosteoporotic effect as compared to an intravenous dose (1.2 micrograms/kg) and 2) search for the relationship between blood level and the hypocalcemic activity of SCT. The pharmacokinetic parameters of subcutaneous SCT (1.2 and 4.7 micrograms/kg) thus estimated were as follows: the area under the blood concentration-time curve (AUC) = 89 and 550 pg.hr/ml, and mean residence time (MRT) = 44 and 65 minutes, respectively, when the AUC for an intravenous SCT (1.2 micrograms/kg) = 160 pg.hr/ml and the MRT = 10 minutes.

Successful transduction of oligodendrocytes and restoration of arylsulfatase A deficiency in metachromatic leukodystrophy fibroblasts using an adenovirus vector

Metachromatic leukodystrophy (MLD) is an inherited metabolic disease which is characterized by deficient activity of arylsulfatase A (ASA). This deficiency causes progressive accumulation of cerebroside sulfate (CS) in oligodendrocytes (OLs) in the brain resulting in dysmyelination. We are developing approaches for treating MLD based on direct delivery of ASA genes to brain. In this paper, we report a recombinant adenovirus (Adex1SRLacZL) that efficiently transduces OLs. Moreover, transduction and expression of the human transgene was efficient in primary fibroblasts from MLD patients exposed to similar recombinant adenovirus carrying the ASA gene (Adex1SRASA) In addition, the expressed ASA protein was correctly targeted to lysosomes and was immunoreactive to anti-ASA antibody. The enzymatic activity of ASA in MLD patient cells is corrected from the deficient state to 2.3 to 5.0 times the activity of normal control cells. These results demonstrate the correction of ASA deficiency by a recombinant adenovirus that is potentially useful for transferring the gene to brain.