Characterization of human-type monoclonal antibodies against reduced form of hemin binding protein 35 from Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

The gram-negative anaerobe Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We previously identified a 35 kDa surface protein (hemin binding protein 35; HBP35) from P. gingivalis that exhibited coaggregation activity, while additional analysis suggested that this protein possessed an ability to bind heme molecules. For development of passive immunotherapy for periodontal diseases, human-type monoclonal antibodies have been prepared using HBP35 as an antigen in TransChromo mice. In the present study, we focused on a single antibody, TCmAb-h13, which is known to inhibit heme binding to recombinant HBP35. The aim of our investigation was to clarify the redox-related function of HBP35 and consider the benefits of human-type monoclonal antibodies.

MATERIAL AND METHODS

To examine the antigen recognition capability of TCmAbs with immunoblotting and Biacore techniques, we used the native form as well as several Cys-to-Ser variants of recombinant HBP35.

RESULTS

We found that the redox state of recombinant HBP35 was dependent on two Cys residues, (48) C and (51) C, in the thioredoxin active center (WCGxCx). Furthermore, TCmAb-h13 recognized the reduced forms of recombinant HBP35, indicating its inhibitory effect on P. gingivalis growth.

CONCLUSION

Hemin binding protein 35 appears to be an important molecule involved in recognition of the redox state of environmental conditions. In addition, TCmAb-h13 had an inhibitory effect on heme binding to recombinant HBP35, thereby interfering with P. gingivalis growth.

[Clinical experience with transurethral resection of bladder tumor (TUR-Bt) guided by photodynamic diagnosis (PDD)]

PURPOSE

To report our clinical experience regarding transurethral resection of bladder tumor (TUR-Bt) guided by photodynamic diagnosis (PDD) with intravesical instillations of 5-aminolevulinic acid (ALA) and to assess the usefulness of the therapeutic method.

MATERIALS AND METHODS

TUR-Bt guided by PDD was performed in 57 patients of which 47 were men and 10 women with a median age of 74.3 years (range 45-90), 36 were primary cases and 21 were recurrent cases with non-muscle invasive bladder cancer. Two to two and half hours prior to endoscopy 1.5 g ALA dissolved in 50 ml of 8.4% sodium hydrogen carbonate (NaHCO3) solution was instilled intravesically. For fluorescence excitation a blue light source (D-LIGHT System, Karl Storz Endoscopy Japan K.K.) was used. The tumorous lesions under white light guidance and the lesion with fluorescent excitation under blue (fluorescence) light guidance were taken by cold cup as a biopsy and also resected sequentially. To evaluate the accuracy of PDD, the levels in images of the ALA-induced fluorescence were compared with the pathological results. To evaluate the availability of TUR-Bt guided by PDD, survival Analysis regarding vesical recurrence was retrospectively examined compared to the cases underwent conventional TUR-Bt under white light guidance. Moreover, in these cases, multivariate analysis using Cox proportional-hazards model was performed to detect the clinico-pathological factor independently contribute to improving prognosis. (Results) In the 301 specimens obtained from 57 patients, the sensitivity and specificity of PDD were 92.5% and 60.1%, whereas the sensitivity and specificity of conventional endoscopic examination under white light guidance were 81.6% and 79.5%, respectively. Median follow-up period was 19.1 (range 8.6-49.9) months in 57 patients underwent TUR-Bt guided by PDD. Eight of 57 patients recurred and recurrence-free survival rate was 88.2 +/- 0.1% (at 12 months) and 76.2 +/- 0.1% (24-48 months). Median follow-up period was 49.9 (5.0-145.0) months in 149 patients underwent conventional TUR-Bt. Ninety-nine of 149 patients recurred and recurrence-free survival rate was 60.3 +/- 0.0% (12 months) and 31.6 +/- 0.0% (24-48 months). There was statistical significance in recurrence-free survival rate between these 2 therapeutic groups (p < 0.001). Moreover, multivariate analysis revealed the independent factor contribute to improving prognosis was only TUR-Bt guided by PDD (hazard ratio 0.279, p = 0.001).

CONCLUSION

It was suggested that TUR-Bt guided by PDD might reduce the risk of vesical recurrence in the early stage after operation of non-muscle invasive bladder cancer.

[Experience in the treatment of eight cases of Fournier's gangrene]

Fournier's gangrene is a rare disease of rapidly progressive necrotising fasciitis of the genital, perineal and perianal regions and leads to sepsis and death. We report 8 cases of Fournier's gangrene treated at our hospital and affiliated hospitals from 1997 to 2007. There were seven males and one female in the series, and the age range was 23-89 years (mean age 56.6 years). Four patients among them had diabetes mellitus. We rescued all patients by broad-spectrum antibacterial chemotherapy and debridement. Good management should be based on broad-spectrum antibacterial chemotherapy, debridement and intensive care.

[Localized Fournier's gangrene of the penis: a case report]

Fournier's gangrene is a rare disease with rapidly progressive necrotising fasciitis of the genital, perineal and perianal regions and leads to sepsis and death. We reported a case of localized Fournier's gangrene of the penis. A 23-year-old man suffered an abrasion of the penis during oral sex with a commercial sex worker. Because pain as well as redness and swelling appeared on the penile surface, he consulted the nearest hospital. Since Fournier's gangrene was suspected, he was admitted to our hospital. According to the clinical symptoms and diagnostic imaging by using magnetic resonance imaging, we diagnosed Fournier's gangrene. Immediately, we started broad-spectrum antibacterial chemotherapy and performed debridement. The postoperative course was good and then the open wound was closed with artificial corium and full thickness skin graft to avoid erectile disturbance.

Identification of the genes associated with a virulent strain of Porphyromonas gingivalis using the subtractive hybridization technique

BACKGROUND/AIMS

Porphyromonas gingivalis, a major etiological organism implicated in periodontal disease, can be classified into virulent and avirulent strains. Our aim was to identify a gene for the virulence of P. gingivalis.

METHODS

The subtractive hybridization technique was employed to identify the genes specific to P. gingivalis W83, a virulent strain. In this study, P. gingivalis W83 was used as the tester strain, and P. gingivalis ATCC 33277 was the driver strain. The prevalence of W83-specific genes was determined by Southern blot analysis of several P. gingivalis strains.

RESULTS

We obtained 575 colonies using the subtractive hybridization technique. From among these, 26 DNA fragments were subjected to a homology search using the BLAST program. Compared with strain ATCC 33277, strain W83 contained 12 unique clones. The specificities of the isolated DNA fragments were analyzed among four P. gingivalis strains by Southern blot analysis. Five genes showed specificity for strain W83 compared with strain ATCC 33277. All five genes were also identified in strain W50.

CONCLUSIONS

The subtractive hybridization technique was effective in screening the two strains for specific DNA sequences, some of which might be responsible for determining virulence. The results suggested that several genes specific to strain W83 were associated with its virulence. Further analysis of these DNA fragments will provide important information on the pathogenesis of virulent P. gingivalis strains.

Effects of KP-496, a novel dual antagonist at the cysteinyl leukotriene receptor 1 and the thromboxane A(2) receptor, on airway obstruction in guinea pigs

BACKGROUND AND PURPOSE

KP-496 is a novel dual antagonist for cysteinyl leukotriene receptor 1 (CysLT(1)) and thromboxane A(2) (TXA(2)) receptor (TP). The aim of this study was to evaluate the pharmacological profile of inhaled KP-496 and its effects on airway obstruction.

EXPERIMENTAL APPROACH

Antagonist activities of inhaled KP-496 were investigated using bronchoconstriction induced in guinea pigs by LTD(4) or U46619, a stable TXA(2) mimetic. Guinea pigs sensitized with injections of ovalbumin were used to assess the effects of inhaled KP-496 on bronchoconstriction induced by antigen (i.v.). Another set of guinea pigs were sensitized and challenged with ovalbumin by inhalation and the effects of inhaled KP-496 on immediate and late airway responses and airway hyperresponsiveness were investigated.

KEY RESULTS

KP-496 significantly inhibited LTD(4)- and U46619-induced bronchoconstriction in a dose-dependent manner. The inhibitory effects of KP-496 (1%) were comparable to those of montelukast (a CysLT(1) antagonist, p.o., 0.3 mg kg(-1)) or seratrodast (a TP antagonist, p.o., 3 mg kg(-1)). KP-496 (1%) and oral co-administration of montelukast (10 mg kg(-1)) and seratrodast (20 mg kg(-1)) significantly inhibited antigen-induced bronchoconstriction, whereas administration of montelukast or seratrodast separately did not inhibit antigen-induced bronchoconstriction. KP-496 exhibited dose-dependent and significant inhibitory effects on the immediate and late airway responses and airway hyperresponsiveness following antigen challenge.

CONCLUSIONS AND IMPLICATIONS

KP-496 exerts effects in guinea pigs which could be beneficial in asthma. These effects of KP-496 were greater than those of a CysLT(1) antagonist or a TP antagonist, in preventing antigen-induced airway obstruction.

Endosialin/TEM1: Cellular localization and prevalence in soft-tissue tumors and carcinomas

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Background: Tumors grow more slowly in endosialin/TEM1 KO mice compared to WT, suggesting that host endosialin/TEM1-positive stroma promotes malignancy (Nanda, PNAS, 2006). Methods: We surveyed 92 human clinical samples by IHC (52 epithelial tumors, 40 sarcomas) to measure the extent of endosialin/TEM1 expression and assess cellular localization. Expression was also studied in primary cell cultures and 49 cancer lines. Results: 46/52 adenocarcinomas and carcinomas (88.5%) expressed endosialin/TEM1 mainly in pericytes (7/7 bladder, 7/11 breast, 5/5 colon, 7/8 ovarian, 7/7 renal, 2/2 liver, 4/5 lung, and 7/7 gastric). In some tumors, endosialin/TEM1 was present in pericytes and in fibroblasts (2/7 bladder, 4/11 breast, 5/5 colon, 5/8 ovarian, 2/7 renal, 2/2 liver, 1/5 lung and 7/7 gastric cancers). 32/40 sarcomas (80%) expressed endosialin/TEM1 mainly in pericytes (10/11 synovial sarcomas, 9/10 malignant fibrous histiocytomas, 3/5 Ewing's sarcomas, 3/5 angiosarcomas, 3/4 rhabdomyosarcomas, 2/2 pleiomorphic sarcomas, 1/1 Kaposi's sarcoma, 0/1 leiomyosarcoma and 1/1 liposarcoma). Synovial sarcomas displayed intense fibroblast staining. Endosialin/TEM1 was expressed by sarcoma cells in a few samples. In culture, we previously showed expression in human fibroblasts, endothelial precursor cells, pericytes and mesenchymal stem cells (MSC). We now report that endosialin/TEM1 mRNA is present in MSC during osteogenic and adipogenic differentiation. In 49 human tumor lines, expression was restricted to sarcoma cells (7/15 sarcoma, 0/5 melanoma, 0/2 neuroblastoma, 0/4 breast, 0/1 ovarian, 0/3 prostate, 0/1 renal, 0/1 liver, 0/3 pancreatic, 0/6 colorectal and 0/8 hematopoietic cancer lines). Conclusions: Endosialin/TEM1 is frequently expressed in clinical cancer (85% of 92 samples), both in epithelial and mesenchymal tumors. Cellular expression is mesenchymal in clinical samples and in culture. In tissues, endosialin/TEM1 is present in pericytes and fibroblasts, with some expression in sarcoma cells. The importance of endosialin/TEM1-positive stroma in experimental animals and prevalence in patient samples warrant further investigation. Endosialin/TEM1 may be a useful therapeutic target.

[Table: see text]

Changes in electrical resistance of sound fissure enamel in first molars for 66 months from eruption

The purposes of this study were to investigate the enamel maturation process in the occlusal pit of sound first molars by measuring electrical resistance. Ninety-nine sound first molars in 34 children (mean age of 6.47 +/- 0.51 years) were measured electrically once every 6 months and were monitored for a maximum of 66 months. Electrical resistance increased during the posteruptive period. However, the results suggest that posteruptive enamel maturation in the occlusal pits may not be completed even 66 months after tooth eruption.

Neonatal alloimmune thrombocytopenia due to an antibody against a labile component of human platelet antigen-3b (Bak b)

We report the second case of neonatal alloimmune thrombocytopenia due to anti-human platelet antigen (HPA)-3b (Bak(b)) antibody. The infant was severely affected with intracranial haemorrhage. Most importantly, we were able to detect this antibody only by using fresh, unfixed platelets as antigen. This antibody was detectable neither by conventional mixed passive haemagglutination, platelet immunofluorescence test using fixed platelets, nor by monoclonal antigen immobilization of platelet antigen assay using solubilized platelets. We assume that this antibody reacts only with fresh platelets and that the antigen is a labile component of HPA-3b (Bak(b)).

A polymorphism in the CYP17 gene relates to the risk of recurrent pregnancy loss

The CYP17 gene encodes the enzyme cytochrome P450c17alpha, which mediates both 17alpha-hydroxylase and 17,20-lyase activity in the steroid biosynthesis pathway. A T-->C polymorphism in the 5' promoter region of CYP17 has been described. To examine the association between recurrent pregnancy loss (RPL) and a polymorphism in CYP17, a case-control study of 117 cases with RPL and 164 controls was conducted. This polymorphism was investigated by PCR/restriction fragment length polymorphism using DNA from peripheral lymphocytes. The T-->C transition in the variant allele (A2) creates a new recognition site for the restriction enzyme MspA1, which permits designation of the wildtype allele (A1) and A2. Women with the A2 allele of CYP17 had an increased risk of RPL [A1/A1 genotype (reference); A1/A2 genotype: odds ratio (OR), 1.68; 95% confidence interval (CI), 0.94-3.01; A2/A2 genotype: OR, 2.37; 95% CI, 1.16-4.83; P trend, 0.016]. Additionally, there was a similar tendency for the increased risk of primary RPL [A1/A1 genotype (reference); A1/A2 genotype: OR, 2.14; 95% CI, 1.14-4.01; A2/A2 genotype: OR, 2.50; 95% CI, 1.16-5.41; P trend, 0.015]. These results suggest that possession of the A2 variant of CYP17 may predispose to an increased risk of RPL with a gene dosage effect.

Mutation in the CHAC gene in a family of autosomal dominant chorea-acanthocytosis

Although mutations in the CHAC gene have been identified in autosomal recessive chorea-acanthocytosis (AR-ChAc), the molecular basis of autosomal dominant ChAc (AD-ChAc) remains to be determined. The authors investigated abnormalities in the CHAC gene in an AD-ChAc family with mRNA and sequencing analyses of mRNA and genomic DNA. A novel single heterozygous mutation in the last nucleotide of exon 57 of the CHAC gene, which could cause skipping of the exon, was detected in affected siblings.

Human normal hepatocytes are susceptible to apoptosis signal mediated by both TRAIL-R1 and TRAIL-R2

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in tumor cells without toxicity to normal cells, but some recombinant versions of TRAIL caused hepatocyte death. We generated fully human monoclonal antibodies (mAbs) that bind specifically to TRAIL receptor 1 (TRAIL-R1) and TRAIL receptor 2 (TRAIL-R2), which mediate apoptosis signal when they ligate with TRAIL, to investigate the contribution of each receptor to induce tumor cell apoptosis and hepatocyte toxicity. All of mAbs to TRAIL-R1 and TRAIL-R2 induced cell death in several cancer cell lines susceptible to TRAIL but not in human umbilical vein endothelial cells in vitro. Both anti-TRAIL-R1 mAbs and anti-TRAIL-R2mAbs also caused cell death in hepatocytes. However, a subset of mAbs to TRAIL-R2, which was characterized by the TRAIL blocking activity, did not show strong hepatocyte toxicity. These results indicate that human normal hepatocytes are susceptible to both TRAIL-R1- and TRAIL-R2-mediated apoptosis signal. Cell Death and Differentiation (2004) 11, 203-207. doi:10.1038/sj.cdd.4401331 Published online 24 October 2003

Rostral lateral pontine infarction: neurological/topographical correlations

The authors correlated neurologic features of rostral lateral pontine infarct (rLPI) with lesion location on MRI. rLPI is a motor-sensory stroke presenting as crural monoparesis or crural dominant hemiparesis and segmental superficial or deep sensory disturbances. The dorsolateral pontine base causes crural paresis without supranuclear facial palsy.

Gastric restitution is inhibited by dexamethasone, which is reversed by hepatocyte growth factor and rebamipide

BACKGROUND

Glucocorticoids have been shown to induce peptic ulcers, especially when co-administered with NSAIDs. Hepatocyte growth factor (HGF) plays a role in gastric ulcer repair, facilitating the restitution of gastric mucosal epithelial cells. HGF expression is induced by PGs in gastric fibroblasts. We hypothesized that dexamethasone (DEX) may inhibit PG production and HGF expression, thus inhibiting HGF-induced gastric epithelial restitution.

AIM

To investigate the effect of DEX on gastric restitution, using cultured gastric cells, the role of HGF in the restitution inhibited by DEX, and the effect of rebamipide on DEX- inhibited restitution.

METHODS

Human gastric fibroblasts were prepared from human stomach obtained at surgery; PGE2 and HGF is determined by ELISA; Restitution was assessed by the round wound restitution model, using coculture of gastric fibroblasts and epithelial cells; COX-2 and HGF mRNA were quantified by TaqMan RT-PCR system.

RESULTS

1. DEX inhibited HGF mRNA and COX-2 mRNA. Accordingly, it inhibited PGE2 and HGF release. 2. DEX inhibited the restitution of gastric cells. 3. The inhibition of restitution was reversed by HGF and rebamipide to the same extent. 4. Rebamipide induced PGE2 and HGF.

CONCLUSION

DEX inhibits restitution via HGF depletion, and rebamipide reverses the inhibited restitution by HGF induction.

Epidermoid cyst originating from an intrapancreatic accessory spleen

Pancreatectomy in a 45-year-old woman showed, after pathologic analysis, an epidermoid cyst originating from an intrapancreatic accessory spleen. This mass consisted of parenchymal and cystic components. It is important to note the relation between the splenic parenchyma and the parenchymal component of the mass for the differential diagnosis of a cystic mass in the pancreatic tail.

Safety evaluation of proanthocyanidin-rich extract from grape seeds

Proanthocyanidins, extracted from grape seeds, are widely used mainly as nutritional supplements. However, there has not been a systematic report to investigate toxicological studies on proanthocyanidins, especially in oral administration. In our studies, proanthocyanidin-rich extract from grape seeds was subjected to a series of toxicological tests to document its safety for use in various foods. The grape seed extract (GSE) was examined for acute and subchronic oral toxicity using Fischer 344 rats and for mutagenic potential by the reverse mutation test using Salmonella typhimurium, the chromosomal aberration test using CHL cells, and the micronucleus test using ddY mice. No evidence of acute oral toxicity at dosages of 2 and 4 g/kg, and no evidence of mutagenicity in the above tests was found. Administration of GSE as a dietary admixture at levels of 0.02, 0.2 and 2% (w/w) to the rats for 90 days did not induce noticeable signs of toxicity. The no-observed-adverse-effect level (NOAEL) of GSE in the subchronic toxicity study was 2% in the diet (equal to 1410 mg/kg body weight/day in males and 1501 mg/kg body weight/day in females). The results of our studies indicate a lack of toxicity and support the use of proanthocyanidin-rich extract from grape seeds for various foods.

Increased apoptosis of human fetal membranes in rupture of the membranes and chorioamnionitis

Apoptosis is thought to participate pathophysiologically in the rupture of human fetal membranes (ROM). The aim of this study was to assess apoptosis of the amnion and the chorion in relation to ROM and chorioamnionitis (CAM). The amnion and chorion at the position of the cervical os and fundus of the uterus were obtained from 44 patients. Apoptotic DNA fragmentation was densitometrically determined, and the relative ratio was used for the quantitative evaluation. Among patients without CAM, the relative ratios of apoptosis in the amnion from patients with ROM were higher than those in patients without ROM (P< 0.05). Among patients without ROM, the apoptotic levels in the amnion from patients with CAM were higher than those in patients without CAM (P< 0.05). These were the cases with the amnion at the position of cervical os and fundus, but not with the chorion. The highest ratio of apoptosis was seen in the amnion from patients with CAM and ROM. Among patients with ROM and no CAM, the apoptotic levels at the cervical os in the amnion (P=0.059) and chorion (P< 0.05) was higher than those at the fundus. The increased apoptosis of human fetal membranes was related to ROM and CAM. Apoptosis plays a role in the pathophysiology of ROM.

Direct interaction of insulin-like growth factor-1 receptor with leukemia-associated RhoGEF

Insulin-like growth factor (IGF)-1 plays crucial roles in growth control and rearrangements of the cytoskeleton. IGF-1 binds to the IGF-1 receptor and thereby induces the autophosphorylation of this receptor at its tyrosine residues. The phosphorylation of the IGF-1 receptor is thought to initiate a cascade of events. Although various signaling molecules have been identified, they appear to interact with the tyrosine-phosphorylated IGF-1 receptor. Here, we identified leukemia-associated Rho guanine nucleotide exchange factor (GEF) (LARG), which contains the PSD-95/Dlg/ZO-1 (PDZ), regulator of G protein signaling (RGS), Dbl homology, and pleckstrin homology domains, as a nonphosphorylated IGF-1 receptor-interacting molecule. LARG formed a complex with the IGF-1 receptor in vivo, and the PDZ domain of LARG interacted directly with the COOH-terminal domain of IGF-1 receptor in vitro. LARG had an exchange activity for Rho in vitro and induced the formation of stress fibers in NIH 3T3 fibroblasts. When MDCKII epithelial cells were treated with IGF-1, Rho and its effector Rho-associated kinase (Rho-kinase) were activated and actin stress fibers were enhanced. Furthermore, the IGF-1-induced Rho-kinase activation and the enhancement of stress fibers were inhibited by ectopic expression of the PDZ and RGS domains of LARG. Taken together, these results indicate that IGF-1 activates the Rho/Rho-kinase pathway via a LARG/IGF-1 receptor complex and thereby regulates cytoskeletal rearrangements.