Porphyromonas gingivalis-odontogenic infection is the potential risk for progression of nonalcoholic steatohepatitis-related neoplastic nodule formation

Porphyromonas gingivalis (P.g.), a major periodontal pathogen is a known risk factor for various systemic diseases. However, the relationship between P.g. and nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) is unclear. Thus, we aimed to elucidate whether P.g.-odontogenic infection promotes NASH-related HCC development/progression and to clarify its mechanism. Using high-fat diet (HFD)-induced NASH mouse model, P.g. was infected odontogenically. After 60 weeks of infection, tumor profiles were examined. Chow diet (CD) groups were also prepared at 60 weeks. Nodule formation was only seen in HFD-mice. P.g.-odontogenic infection significantly increased the mean nodule area (P = 0.0188) and tended to promote histological progression score after 60 weeks (P = 0.0956). Interestingly, P.g. was detected in the liver. HFD-P.g. (+) showed numerous TNF-α positive hepatic crown-like structures and 8-OHdG expression in the non-neoplastic liver. In P.g.-infected hepatocytes, phosphorylation of integrin β1 signaling molecules (FAK/ERK/AKT) was upregulated in vitro. In fact, total AKT in the liver of HFD-P.g. (+) was higher than that of HFD-P.g. (-). P.g.-infected hepatocytes showed increased cell proliferation and migration, and decreased doxorubicin-mediated apoptosis. Integrin β1 knockdown inhibited these phenotypic changes. P.g.-odontogenic infection may promote the progression of neoplastic nodule formation in an HFD-induced NASH mouse model via integrin signaling and TNF-α induced oxidative DNA damage.

The RGD region of bone sialoprotein affects metabolic activity in mice

Introduction

Bone sialoprotein (BSP) is a key regulator of mineralized tissue formation. Previously, we generated BSP-KAE knock-in mice (KAEKI mice) by substituting a non-function KAE (lysine-alanine-glutamic acid) for the integrin-binding RGD (arginine-glycine-aspartic acid) sequence and reported a vital role of the BSP-RGD motif in modulating the periodontal ligament (PDL). Specifically, histologically a disorganization of the PDL was noted, resulting in a weakened function of the PDL as measured by dynamic mechanical analysis. Intriguingly, also noted was a weight gain as KAEKI mice aged. While several proteins associated with mineralized tissues are reported to affect energy metabolism, the metabolic role of the BSP-RGD region has yet to be elucidated. Here we focus on defining the role of the BSP-RGD region in metabolic activity.

Methods

Body weight, body composition, and caloric intake were measured in wild type (WT) and KAEKI mice. Energy expenditure was estimated using energy balance technique. Epididymal fat, interscapular fat, and liver were harvested for histological analysis. Systemic metabolic phenotype was assessed by sera analyses, insulin tolerance and glucose tolerance tests.

Results

The results showed that KAEKI mice developed mild obesity starting from 13 weeks postnatal (wpn). The increase in body weight correlated with an increase in lean mass and visceral adiposity. Histological examination revealed adipocyte hypertrophy in white epididymal fat and interscapular brown fat in KAEKI vs. WT mice at 17 wpn. Metabolic profiling indicated that KAEKI mice had dyslipidemia and hyperleptinemia but no significant changes in glucose metabolism. Energy balance analyses revealed that hyperphagia preceded weight gain in KAEKI mice.

Conclusion

These data suggest that the RGD region of BSP affects energy metabolism by regulating food intake, with further studies warranted to uncover the underlying mechanisms.

Cyclic pressure-induced cytokines from gingival fibroblasts stimulate osteoclast activity: Clinical implications for alveolar bone loss in denture wearers

Purpose The involvement of oral mucosa cells in mechanical stress-induced bone resorption is unclear. The aim of this study was to investigate the effects of cyclic pressure-induced cytokines from oral mucosal cells (human gingival fibroblasts: hGFs) on osteoclast activity in vitro.Methods Cyclic pressure at 50 kPa, which represents high physiologic occlusal force of dentures on the molar area, was applied to hGFs. NFAT-reporter stable RAW264.7 preosteoclasts (NFAT/Luc-RAW cells) were cultured in conditioned medium collected from hGF cultures under cyclic pressure or static conditions. NFAT activity and osteoclast formation were determined by luciferase reporter assay and TRAP staining, respectively. Cyclic pressure-induced cytokines in hGF culture were detected by ELISA, real-time RT-PCR, and cytokine array analyses.Results Conditioned media from hGFs treated with 48 hours of cyclic pressure significantly induced NFAT activity and increased multinucleated osteoclast formation. Furthermore, the cyclic pressure significantly increased the bone resorption activity of RAW264.7 cells. Cyclic pressure significantly increased the expression of major inflammatory cytokines including IL-1β/IL-1β, IL-6/IL-6, IL-8/IL-8 and MCP-1/CCL2 in hGFs compared to hGFs cultured under static conditions, and it suppressed osteoprotegerin (OPG/OPG) expression. A cytokine array detected 12 cyclic pressure-induced candidates. Among them, IL-8, decorin, MCP-1 and ferritin increased, whereas IL-28A and PDGF-BB decreased, NFAT activation of NFAT/Luc-RAW cells.Conclusions These results suggest that cyclic pressure-induced cytokines from hGFs promote osteoclastogenesis, possibly including up-regulation of IL-1β, IL-6, IL-8 and MCP-1, and down-regulation of OPG. These findings introduce the possible involvement of GFs in mechanical stress-induced alveolar ridge resorption, such as in denture wearers.

The Bone Sialoprotein RGD Domain Modulates and Maintains Periodontal Development

Bone sialoprotein (gene: Ibsp; protein: BSP) is a multifunctional extracellular matrix protein present in bone, cementum, and dentin. Accumulating evidence supports BSP as a key regulator of mineralized tissue formation via evolutionarily conserved functional domains, including a C-terminal integrin-binding Arg-Gly-Asp (RGD) domain implicated in extracellular matrix-cell signaling. Ablation of Ibsp in mice (Ibsp-/-) results in impaired bone growth and mineralization and defective osteoclastogenesis, with effects in the craniofacial region including reduced acellular cementum formation, detachment of the periodontal ligament (PDL), alveolar bone hypomineralization, and severe periodontal breakdown. We hypothesized that BSP-RGD plays an important role in cementum and alveolar bone formation and mineralization, as well as periodontal function. This hypothesis was tested by replacing the RGD motif with a nonfunctional Lys-Ala-Glu (KAE) sequence in (IbspKAE/KAE) mice and OCCM.30 murine (IbspKAE) cementoblasts. The RGD domain was not critical for acellular or cellular cementum formation in IbspKAE/KAE mice. However, PDL volume and thickness were increased, and significantly more tartrate-resistant acid phosphatase-positive osteoclasts were found on alveolar bone surfaces of IbspKAE/KAE mice versus wild type mice. PDL organization was disrupted as indicated by picrosirius red stain, second harmonic generation imaging, dynamic mechanical analysis, and decreased asporin proteoglycan localization. In vitro studies implicated RGD functions in cell migration, adhesion, and mineralization, and this was confirmed by an ossicle implant model where cells lacking BSP-RGD showed substantial defects as compared with controls. In total, the BSP-RGD domain is implicated in periodontal development, though the scale and scope of changes indicated by in vitro studies indicate that other factors may partially compensate for and reduce the phenotypic severity of mice lacking BSP-RGD in vivo.

Elimination of Porphyromonas gingivalis inhibits liver fibrosis and inflammation in NASH

AIM

Non-alcoholic steatohepatitis (NASH) is a critical liver disease showing potential progression to liver cirrhosis/cancer. Previously, we had reported that odontogenic infection of Porphyromonas gingivalis (P. gingivalis), a major periodontal pathogen, exacerbates fibrosis in NASH through the production of fibrosis mediators such as transforming growth factor-β1 (TGF-β1) and galectin-3. In this study, we determined the effects of therapeutic interventions using antibiotics on NASH progression induced by P. gingivalis odontogenic infection.

MATERIALS AND METHODS

To eliminate P. gingivalis infection, the macrolide antibiotic [azithromycin (AZM)] was applied locally and/or systemically to a high-fat-diet-induced NASH mouse model with P. gingivalis odontogenic infection. After treatment with AZM, liver and periodontal tissues were analysed with focus on inflammation markers such as tumour necrosis factor-α (TNF-α)/Tnf-α and interleukin-1β (IL-1β)/Il-1β, and fibrosis markers such as galectin-3, phosphorylated Smad2 (pSmad2; key signalling molecule of TGF-β1), and the number of hepatic crown-like structures (hCLSs). Further, Non-alcoholic Fatty Liver Disease Activity Score (NAS), a common histological scoring system, and fibrosis area were evaluated.

RESULTS

P. gingivalis odontogenic infection significantly increased the expression of Tnf-α, Il-1β, galectin-3, and pSmad2, the number of hCLSs, and NAS score, whereas the elimination of P. gingivalis odontogenic infection, especially local with or without systemic application, significantly inhibited them.

CONCLUSION

This study suggests that elimination of P. gingivalis odontogenic infection inhibited NASH progression induced by the infection.

Delivery of Alkaline Phosphatase Promotes Periodontal Regeneration in Mice

Factors regulating the ratio of pyrophosphate (PP_i) to phosphate (P_i) modulate biomineralization. Tissue-nonspecific alkaline phosphatase (TNAP) is a key promineralization enzyme that hydrolyzes the potent mineralization inhibitor PP_i. The goal of this study was to determine whether TNAP could promote periodontal regeneration in bone sialoprotein knockout mice (Ibsp^-/- mice), which are known to have a periodontal disease phenotype. Delivery of TNAP was accomplished either systemically (through a lentiviral construct expressing a mineral-targeted TNAP-D₁₀ protein) or locally (through addition of recombinant human TNAP to a fenestration defect model). Systemic TNAP-D₁₀ delivered by intramuscular injection at 5 d postnatal (dpn) increased circulating alkaline phosphatase (ALP) levels in Ibsp^-/- mice by 5-fold at 30 dpn, with levels returning to normal by 60 dpn when tissues were evaluated by micro-computed tomography and histology. Local delivery of recombinant human TNAP to fenestration defects in 5-wk-old wild type (WT) and Ibsp^-/- mice did not alter long-term circulating ALP levels, and tissues were evaluated by micro-computed tomography and histology at postoperative day 45. Systemic and local delivery of TNAP significantly increased alveolar bone volume (20% and 37%, respectively) and cementum thickness (3- and 42-fold) in Ibsp^-/- mice, with evidence for periodontal ligament attachment and bone/cementum marker localization. Local delivery significantly increased regenerated cementum and bone in WT mice. Addition of 100-μg/mL bovine intestinal ALP to culture media to increase ALP in vitro increased media P_i concentration, mineralization, and Spp1 and Dmp1 marker gene expression in WT and Ibsp^-/- OCCM.30 cementoblasts. Use of phosphonoformic acid, a nonspecific inhibitor of sodium P_i cotransport, indicated that effects of bovine intestinal ALP on mineralization and marker gene expression were in part through P_i transport. These findings show for the first time through multiple in vivo and in vitro approaches that pharmacologic modulation of P_i/PP_i metabolism can overcome periodontal breakdown and accomplish regeneration.

Ablation of Pyrophosphate Regulators Promotes Periodontal Regeneration

Biomineralization is regulated by inorganic pyrophosphate (PP_i), a potent physiological inhibitor of hydroxyapatite crystal growth. Progressive ankylosis protein (ANK) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) act to increase local extracellular levels of PP_i, inhibiting mineralization. The periodontal complex includes 2 mineralized tissues, cementum and alveolar bone (AB), both essential for tooth attachment. Previous studies demonstrated that loss of function of ANK or ENPP1 (reducing PP_i) resulted in increased cementum formation, suggesting PP_i metabolism may be a target for periodontal regenerative therapies. To compare the effects of genetic ablation of Ank, Enpp1, and both factors concurrently on cementum and AB regeneration, mandibular fenestration defects were created in Ank knockout (Ank KO), Enpp1 mutant (Enpp1^asj/asj), and double KO (dKO) mice. Genetic ablation of Ank, Enpp1, or both factors increased cementum regeneration compared to controls at postoperative days (PODs) 15 and 30 (Ank KO: 8-fold, 3-fold; Enpp1^asj/asj: 7-fold, 3-fold; dKO: 11-fold, 4-fold, respectively) associated with increased fluorochrome labeling and expression of mineralized tissue markers, dentin matrix protein 1 (Dmp1/DMP1), osteopontin (Spp1/OPN), and bone sialoprotein (Ibsp/BSP). Furthermore, dKO mice featured increased cementum thickness compared to single KOs at POD15 and Ank KO at POD30. No differences were noted in AB volume between genotypes, but osteoblast/osteocyte markers were increased in all KOs, partially mineralized osteoid volume was increased in dKO versus controls at POD15 (3-fold), and mineral density was decreased in Enpp1^asj/asj and dKOs at POD30 (6% and 9%, respectively). Increased numbers of osteoclasts were present in regenerated AB of all KOs versus controls. These preclinical studies suggest PP_i modulation as a potential and novel approach for cementum regeneration, particularly targeting ENPP1 and/or ANK. Differences in cementum and AB regeneration in response to reduced PP_i conditions highlight the need to consider tissue-specific responses in strategies targeting regeneration of the entire periodontal complex.

Genetic and pharmacologic modulation of cementogenesis via pyrophosphate regulators

Pyrophosphate (PP_i) serves as a potent and physiologically important regulator of mineralization, with systemic and local concentrations determined by several key regulators, including: tissue-nonspecific alkaline phosphatase (ALPL gene; TNAP protein), the progressive ankylosis protein (ANKH; ANK), and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1; ENPP1). Results to date have indicated important roles for PP_i in cementum formation, and we addressed several gaps in knowledge by employing genetically edited mouse models where PP_i metabolism was disrupted and pharmacologically modulating PP_i in a PP_i-deficient mouse model. We demonstrate that acellular cementum growth is inversely proportional to PP_i levels, with reduced cementum in Alpl KO (increased PP_i levels) mice and excess cementum in Ank KO mice (decreased PP_i levels). Moreover, simultaneous ablation of Alpl and Ank results in reestablishment of functional cementum in dKO mice. Additional reduction of PP_i by dual deletion of Ank and Enpp1 does not further increase cementogenesis, and PDL space is maintained in part through bone modeling/remodeling by osteoclasts. Our results provide insights into cementum formation and expand our knowledge of how PP_i regulates cementum. We also demonstrate for the first time that pharmacologic manipulation of PP_i through an ENPP1-Fc fusion protein can regulate cementum growth, supporting therapeutic interventions targeting PP_i metabolism.

Central mucoepidermoid carcinoma arising from glandular odontogenic cyst confirmed by analysis of MAML2 rearrangement: A case report

Central mucoepidermoid carcinoma (MEC) poses a diagnostic challenge because of its rarity and histological overlap with glandular odontogenic cyst (GOC). In MEC of both salivary glands and jaws, MAML2 arrangement has been well known as the specific gene alteration. We report a case of central MEC arising from GOC diagnosed by MAML2 fusion gene. A 57-year-old male presented a multilocular cystic lesion in left molar region of the mandible. Histopathologically, multiple cysts lined by thin cuboidal or non-keratinized squamous epithelium with small duct-like structures, mucous cells and ciliated cells were present. It was diagnosed as GOC. The recurrent lesion after nine years showed the proliferation of many cystic and solid nests composed of epidermoid, mucous and intermediated cells. Nested PCR revealed CRTC3-MAML2 fusion gene in the recurrent lesion, but not in the primary one. Similarly, MAML-2 rearrangement by FISH analysis was positive in the recurrent lesion, while negative for the primary one, thus confirming the diagnosis of central MEC arising from GOC. Analysis of MAML2 rearrangement can be used as a supportive evidence to distinguish central MEC from GOC.

Osteodystrophy in Cholestatic Liver Diseases Is Attenuated by Anti-γ-Glutamyl Transpeptidase Antibody

BACKGROUND

Cholestatic liver diseases exhibit higher levels of serum γ-glutamyl transpeptidase (GGT) and incidence of secondary osteoporosis. GGT has been identified as a novel bone-resorbing factor that stimulates osteoclast formation. The aim of this study was to elucidate the interaction of elevated GGT levels and cholestatic liver disease-induced bone loss.

METHODS

Wistar rats were divided into three groups: sham-operated control (SO) rats, bile duct ligation (BDL) rats, and anti-GGT antibody-treated BDL rats (AGT). Serum GGT level was measured. Bone mineral density (BMD) was analyzed by dual-energy X-ray absorptiometry. Bone morphometric parameters and microarchitectural properties were determined by micro-computed tomography and histomorphometry of the distal metaphysis of femurs. Alterations of bone metabolism-related factors were evaluated by cytokine array. Effects of GGT on osteoblasts or stromal cells were evaluated by RT-PCR, enzyme activity, and mineralization ability.

RESULTS

Serum levels of GGT were significantly elevated in the BDL-group. In the BDL group, BMD, bone mass percentage, and osteoblast number were significantly decreased, whereas osteoclast number was significantly increased. These alterations were markedly attenuated in the AGT group. The mRNA levels of vascular endothelial growth factor-A, LPS-induced CXC chemokine, monocyte chemoattractant protein-1, tumor necrosis factor-α interleukin-1β and receptor activator of nuclear factor-kappa B ligand were upregulated, and those of interferon-γ and osteoprotegerin were downregulated in the GGT-treated stromal cells. Furthermore, GGT inhibited mineral nodule formation and expression of alkaline phosphatase and bone sialo-protein in osteoblastic cells.

CONCLUSION

Our results indicate that elevated GGT level is involved in hepatic osteodystrophy through secretion of bone resorbing factor from GGT-stimulated osteoblasts/bone marrow stromal cells. In addition, GGT also possesses suppressive effects on bone formation. Managing elevated GGT levels by anti-GGT antibody may become a novel therapeutic agent for hepatic osteodystrophy in chronic liver diseases.

Dental Infection of Porphyromonas gingivalis Induces Preterm Birth in Mice

BACKGROUND

Epidemiological studies have revealed a link between dental infection and preterm birth or low birth weight (PTB/LBW), however, the underlying mechanisms remain unclear. Progress in understanding the associated mechanisms has been limited in part by lack of an animal model for chronic infection-induced PTB/LBW, mimicking pregnancy under conditions of periodontitis. We aimed to establish a mouse model of chronic periodontitis in order to investigate the link between periodontitis and PTB/LBW.

METHODS

To establish chronic inflammation beginning with dental infection, we surgically opened mouse (female, 8 weeks old) 1st molar pulp chambers and directly infected with w83 strain Porphyromonas gingivalis (P.g.), a keystone periodontal pathogen. Mating was initiated at 6 wks post-infection, by which time dental granuloma tissue had developed and live P.g. was cultured from extracted tooth root, which serves as a persistent source of P.g. The gestational day (gd) and birth weight were recorded during for P.g.-infected and control mice, and serum and placental tissues were collected at gd 15 to evaluate the systemic and local conditions during pregnancy.

RESULTS

Dental infection with P.g. significantly increased circulating TNF-α (2.5-fold), IL-17 (2-fold), IL-6 (2-fold) and IL-1β (2-fold). The P.g.-infected group delivered at gd 18.25 vs. gd 20.45 in the non-infected control (NC) group (p < 0.01), and pups exhibited LBW compared to controls (p < 0.01). P.g. was localized to placental tissues by immunohistochemistry and PCR, and defects in placental tissues of P.g. infected mice included premature rupture of membrane, placental detachment, degenerative changes in trophoblasts and endothelial cells, including necrotic areas. P.g. infection caused significantly increased numbers of polymorphonuclear leukocytes (PMNLs) and macrophages in placental tissues, associated with increased local expression of pro-inflammatory mediators including TNF-α and COX-2. Further placental tissue damage was indicated in P.g. infected mice by decreased CD-31 in endothelial cells, increased expression of 8OHdG, an indicator of oxidative DNA damage, and cleaved caspase-3, a marker of apoptosis. In vitro, P.g. lipopolysaccharide significantly increased expression of COX-2, IL-8 and TNF-α, in HTR-8 trophoblasts in an NF-κB-dependent fashion.

CONCLUSIONS

Our novel mouse model supports previous epidemiological studies signifying dental infection as predisposing factor for PTB/LBW. We demonstrate PTB and LBW in infected mice, translocation of P.g to placental tissues, increased circulating and local pro-inflammatory markers, and the capability of P.g. LPS to directly induce cytokine production in trophoblasts, in vitro. These findings further underscore the importance of local and systemic infections and inflammation during pregnancy and suggest that prevention and/or elimination of dental infections such as marginal or periapical periodontitis before pregnancy may have a beneficial effect on PTB/LBW.

Infection with Porphyromonas gingivalis exacerbates endothelial injury in obese mice

BACKGROUND

A number of studies have revealed a link between chronic periodontitis and cardiovascular disease in obese patients. However, there is little information about the influence of periodontitis-associated bacteria, Porphyromonas gingivalis (Pg), on pathogenesis of atherosclerosis in obesity.

METHODS

In vivo experiment: C57BL/6J mice were fed with a high-fat diet (HFD) or normal chow diet (CD), as a control. Pg was infected from the pulp chamber. At 6 weeks post-infection, histological and immunohistochemical analysis of aortal tissues was performed. In vitro experiment: hTERT-immortalized human umbilical vein endothelial cells (HuhT1) were used to assess the effect of Pg/Pg-LPS on free fatty acid (FFA) induced endothelial cells apoptosis and regulation of cytokine gene expression.

RESULTS

Weaker staining of CD31 and increased numbers of TUNEL positive cells in aortal tissue of HFD mice indicated endothelial injury. Pg infection exacerbated the endothelial injury. Immunohistochemically, Pg was detected deep in the smooth muscle of the aorta, and the number of Pg cells in the aortal wall was higher in HFD mice than in CD mice. Moreover, in vitro, FFA treatment induced apoptosis in HuhT1 cells and exposure to Pg-LPS increased this effect. In addition, Pg and Pg-LPS both attenuated cytokine production in HuhT1 cells stimulated by palmitate.

CONCLUSIONS

Dental infection of Pg may contribute to pathogenesis of atherosclerosis by accelerating FFA-induced endothelial injury.

Synthetic ameloblastin peptide stimulates differentiation of human periodontal ligament cells

OBJECTIVE

This study investigates the effect of the N-terminal region of a synthetic porcine ameloblastin peptide on the proliferation and differentiation of human periodontal ligament cells (PDLC).

DESIGN

We used a cell counter to assess the effect of ameloblastin peptides on the proliferation of PDLC. To investigate the effect of ameloblastin peptides on the differentiation of PDLC, we examined quantitative analysis of alkaline phosphatase (ALP) activity by the Bessey-Lowry enzymological method, mineral nodule formation by Dahl's method, and expression of mineralization-related genes by RT-PCR. We used an anti-ameloblastin antibody to determine whether stimulation of ALP activity was caused by the peptide.

RESULTS

At all concentrations examined, the effect of the ameloblastin peptide on cell proliferation was not significantly different compared with the control. However, the peptide significantly stimulated ALP activity in a dose-dependent manner. ALP activity was significantly inhibited by an anti-ameloblastin antibody, which caused ALP levels to revert to their approximate levels in the untreated condition. At concentrations greater than 1ng/ml, the peptide promoted mineralized nodule formation of PDLC. And the peptide induced higher expressions of ALP and bone sialoprotein (BSP) than the control.

CONCLUSION

Our results show that the ameloblastin peptide upregulate ALP and BSP levels and can enhance calcification of PDLC. Thus, we suggest that the N-terminal synthetic ameloblastin peptide promotes the differentiation activity of PDLC.

Clinical characteristics and the prognosis of rhabdomyosarcoma - a report from the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

AIM

There have been no nationwide group studies for patients with rhabdomyosarcoma in Japan. This study aims to assess the actual state of treatments and their outcome.

PATIENTS AND METHODS

From 1982 to 1996, 79 rhabdomyosarcomas were registered by the Study Group for Pediatric Solid Malignant Tumors in the Kyushu Area. The prognostic factors and treatments were assessed based on the 5-year survival rate. The staging was done according to the Intergroup Rhabdomyosarcoma Study (IRS) Clinical Grouping Classification.

RESULTS

The 5-year survival rate for all patients was 39.1 %. The survival rates for each factor were as follows, according to 1) group; 77.8 % for Group I, 51.9 % for Group II, 33.7 % for Group III, and 20.2 % for Group IV; 2) primary site: 56.3 % for the head and neck, 43.8 % for the parameningeal region, 12.5 % for the extremity, 58.3 % for the genitourinary region, and 30.5 % for the others; 3) histology: 35.8 % for the embryonal type, 36.8 % for the alveolar type.

CONCLUSIONS

Altogether, the outcome of this study was poor. To improve outcomes, a new nationwide group study for rhabdomyosarcoma, which we belong to, has just started in Japan.

An abnormal distribution of C-kit positive cells in the normoganglionic segment can predict a poor clinical outcome in patients with Hirschsprung's disease

PURPOSE

The loss or decrease of interstitial cells of Cajal (ICCs) has been implicated in several disorders of human intestinal motility. We have encountered a few cases suffering from severe constipation or enterocolitis resulting in patient death after a definitive operation for HD, even though the normoganglionic intestine had been successfully pulled through. We investigated the distribution of ICCs using c-kit immunostaining in the normoganglionic segment and compared these findings with the clinical outcome after a definitive operation in each case.

PATIENTS AND METHODS

The distributions of ICCs were investigated by using c-kit immunostaining in the normoganglionic segment in the resected bowel in 15 cases with HD. The distributions of protein gene product 9.5 (PGP 9.5) as a general neuronal marker and those of NADPH-diaphorase (NADPH-d) as a marker of nitric-oxide neurons were also examined. The numbers of ICCs and neurons were evaluated quantitatively. The histopathological results were compared with the clinical outcome after definitive operation in each case.

RESULTS

C-kit immunoreactive cells showed a normal distribution in the normoganglionic segment in 13 cases, while they were markedly (less than 50% compared with the other cases) decreased in 2 cases. The distributions of PGP 9.5 and NADPH-d were almost the same in all cases. The bowel movements of 13 cases showing normal c-kit distribution were satisfactory. In contrast, the bowel movements were impaired in 2 cases with a decreased number of c-kit positive cells. One infant suffered from severe persistent constipation and thus had to undergo a resection of a dilated colon. The other infant died of sepsis due to postoperative enterocolitis and showed a markedly dilated colon.

CONCLUSION

A decreased number of c-kit positive cells in the normoganglionic segment can thus allow us to predict a poor clinical outcome after definitive surgery, probably due to poor intestinal motility. Therefore examining the c-kit distribution in a resected bowel specimen in patients with HD should be mandatory in order to select the optimal postoperative treatment regimen for each case.

Improved survival outcome for hepatoblastoma based on an optimal chemotherapeutic regimen--a report from the study group for pediatric solid malignant tumors in the Kyushu area

BACKGROUND/PURPOSE

The survival outcome for patients with hepatoblastoma normally depends on the resectability of the tumor. In Japan, the pre and/or postoperative chemotherapy protocol using a combination of cisplatin (CDDP) and tetrahydropyranyl-Adriamycin (THP-ADR) has been the standard treatment since 1991. This study aims to assess exactly what influence the establishment of this chemotherapy protocol has had on both the tumor resectability and the outcome of patients with hepatoblastoma.

METHODS

From 1982 to 1997, 60 patients with hepatoblatoma were treated in the Kyushu area, Japan. Based on the pretreatment extent of disease (PRETEXT), the outcome and tumor resectability were compared between group A (1982 to 1990, n = 27, PRETEXT I:5, II:8, III:6, IV:8) and group B (1991 to 1997, n = 33, PRETEXT I:9, II:9, III:5, IV:10).

RESULTS

The 5-year survival rates (group A and group B) were 33% and 73% for all cases (P <.01), 100% and 89% for PRETEXT I, 38% and 89% for II (P <.05), 17% and 80% for III (P <.01), and 0% and 40% for IV (P <.01), respectively. The 5-year survival rates for patients with metastases were 0% for group A (n = 5) and 57% for group B (n = 7; P <.01). The rates of a complete resection of primary tumor were 48% for group A and 67% for group B. In particular, a significant difference was found regarding the complete resection rate between groups A and B in the patients with PRETEXT III (17% for group A and 80% for group B; P <.01). In the patients with an incomplete tumor resection (14 for group A, 11 for group B), the 5-year survival rates were 0% for group A and 45% for group B (P <.01).

CONCLUSIONS

The optimal chemotherapeutic regimen of CDDP and THP-ADR was thus found to greatly contribute to the improved survival rate of hepatoblastoma patients. Preoperative chemotherapy resulted in an increased resectability of the tumor, whereas postoperative chemotherapy played an important role in the increased cure rate of cases with either an incomplete tumor resection or metastasis. However, refractory cases with PRETEXT IV or metastasis may still require the development of an even more effective treatment modality, including the use of blood stem cell transplantation.

Malignant germ cell tumors: clinical characteristics, treatment, and outcome. A report from the study group for Pediatric Solid Malignant Tumors in the Kyushu Area, Japan

PURPOSE

This study aims to assess the prognostic factors and optimal treatments for malignant germ cell tumors (MGCT) in childhood.

METHODS

Among 117 MGCT, the clinical features were analyzed. Regarding the histology, there were 89 embryonal carcinomas, 13 dysgerminomas, 4 choriocarcinomas, and 11 others. The prognostic factors and treatments were assessed based on the 5-year survival rate.

RESULTS

(1) Stage: 100% for stage I (n = 54), 75.0% for stage II (n = 4), 67.3% for stage III (n = 14), and 54.8% for stage IV (n = 33); Unknown: n = 12. (2) Primary site: 93.4% for the testis (n = 52), 86.7% for the ovary (n = 31), 56.9% for the sacrococcygeal (n = 21), and 60.6% for others (n = 12); unknown: n = 1. (3) Surgical intervention for primary tumor: 100% for stage I with a complete resection (n = 53), 78.4% for stage III, IV with a complete resection (n = 26), and 33.3% for stage III, IV with an incomplete resection (n = 21). (4) Type of chemotherapy for the stage III and IV: 83.9% for the PVB (cisplatin, vinblastin, bleomycin; n = 13), 66.7% for the VAC (vincristine, actinomycin D, cyclophosphamide; n = 6), and 47.1% for other regimens (n = 25).

CONCLUSIONS

An early stage, a diagnosis under 1 year of age and a primary site in the gonads were favorable prognosis factors, whereas histologic findings of choriocarcinoma and liver or lung metastasis were unfavorable. Radical complete resection alone is a sufficient treatment for localized MGCT. The PVB regimen is optimal chemotherapy for advanced MGCT; however, high-risk cases still may require more aggressive treatment.

Genetic approaches to dissect the mechanisms of two distinct pathways of cell cycle-coupled cytokinesis in Dictyostelium

Dictyostelium discoideum is a unique experimental organism which allows genetic analysis of the mechanism of cytokinesis of the animal type, and a number of mutations which affect cytokinesis in one way or other have been identified. Myosin II filaments accumulate in the equatorial region, and myosin II-null cells cannot divide in suspension, indicating that active, myosin II-dependent constriction of the cleavage furrow contributes to bisection of the cell. We refer to this method of cytokinesis as cytokinesis A. On substrates, however, myosin II-null cells divide efficiently in a cell cycle-coupled manner. This adhesion-dependent but myosin II-independent division method, which we termed cytokinesis B, is carried out by a pathway that is genetically distinct from that of cytokinesis A. Morphological analyses suggested that cytokinesis B is driven by radial traction forces generated along polar peripheries, which indirectly cause furrow ingression. Identification of two redundant pathways have allowed us to search genes involved in either pathway by mutagenizing cells which are already defective in one of the pathways. This approach enabled us to identify a number of novel cytokinesis-related genes, as well as to reclassify known genes as cytokinesis-related.

Activated protein C prevents endotoxin-induced hypotension in rats by inhibiting excessive production of nitric oxide

BACKGROUND

Excessive production of nitric oxide (NO) by the inducible isoform of NO synthase (iNOS) is critically involved in endotoxin (ET)-induced hypotension. Tumor necrosis factor-alpha (TNF-alpha) plays an important role in induction of iNOS. Because activated protein C (APC), a physiological anticoagulant, inhibits TNF-alpha production, it might prevent hypotension by inhibiting excessive production of NO. In this study, we examined this possibility using a rat model of septic shock.

METHODS AND RESULTS

Intravenous administration of APC prevented both ET-induced hypotension and the increases in plasma levels of NO(2)(-)/NO(3)(-). The hypotension was also inhibited when APC was administered 30 minutes after ET administration. APC inhibited the increases in lung levels of iNOS activity by inhibiting expression of iNOS mRNA in animals given ET. APC significantly inhibited the increases in lung tissue levels of TNF-alpha and expression of TNF-alpha mRNA in animals given ET. Neither DEGR-F.Xa, a selective inhibitor of thrombin generation, nor DIP-APC, an active site-blocked APC, showed any effect on these ET-induced changes. Both inhibition of TNF-alpha production by leukocytopenia and treatment with anti-rat TNF-alpha antibody produced effects similar to those induced by APC. Aminoguanidine, a selective inhibitor of iNOS, inhibited both the hypotension and the increases in plasma levels of NO(2)(-)/NO(3)(-) in this animal model.

CONCLUSIONS

These observations strongly suggest that APC inhibits iNOS induction by decreasing TNF-alpha production, leading to the prevention of ET-induced hypotension. Furthermore, such effects of APC were not dependent on its anticoagulant effects but rather on its serine protease activity.

Clinical and biologic characteristics for recurring neuroblastoma at mass screening cases in Japan

BACKGROUND

It is said that most cases detected by neuroblastoma mass screening at 6 months of age tend to have a favorable clinical course after a surgical resection either with or without mild chemotherapy. However, a few cases have an unfavorable outcome. In the current study, the authors analyzed the clinical and biologic characteristics for recurring neuroblastoma in mass screening cases.

METHODS

In 245 cases detected through mass screening in the Kyushu area in Japan, the clinical data and biologic features (N-myc status, DNA ploidy, Shimada histology, neuron-specific enolase (NSE), ferritin) were investigated, whereas, in particular, the data for recurring cases also were analyzed.

RESULTS

Of 245 cases, 28 tumors had one or more biologically unfavorable prognostic factors, and 6 patients experienced recurrence. Three of the six patients with recurring disease underwent a complete resection of the primary tumor, whereas three cases had undergone an incomplete resection of the tumor. Regarding the initial chemotherapy, three cases received mild chemotherapy, two cases received no chemotherapy, and one case had high-dose multidrug chemotherapy. Regarding biologic prognostic factors, four of six cases with recurring disease had one or more unfavorable factors, whereas two cases had no unfavorable factors. Regarding the outcome after recurrence, four cases are CR, one case has a stable residual tumor, and one case died of disease with N-myc amplification.

CONCLUSIONS

Most neuroblastomas detected by mass screening at 6 months of age have biologically favorable factors. However, approximately 10% of the cases had one or more unfavorable factors and thus might have a higher risk of recurrence than the patients with no unfavorable factors. Conversely, some cases with recurring disease had no unfavorable factors; however, the reason for this is still unclear. A long-term follow-up for mass screening cases is important, and it also might be necessary to research the established biologic factors and identify other new prognostic factors.

Improved survival for patients with advanced neuroblastoma after high-dose combined chemotherapy based in part on N-myc amplification

BACKGROUND/PURPOSE

In spite of many different kinds of chemotherapy for neuroblastoma, the prognosis for advanced neuroblastoma remains unsatisfactory. In particular, the outcome of advanced neuroblastoma with high copies of the N-myc gene tend to be poor. Therefore, the new high-dosage combined chemotherapy regimens for advanced neuroblastoma based in part on the N-myc amplification status has been utilized in the Kyushu area of Japan since 1991. This study aims to investigate whether these new regimens based in part on N-myc amplification have improved the survival rate of stage III and stage IV patients in comparison with the old regimens.

METHODS

Between 1983 and 1995, 77 patients over 1 year of age and with stage III or IV neuroblastoma were registered in the Kyushu Area. Between 1983 and 1990, 49 patients received 1 of 2 combined chemotherapy regimens consisting of cyclophosphamide, cisplatin plus VM-26, and Adriamycin plus DTIC. Since 1991, two new regimens (New A1 and A3) have been administered based on the N-myc amplification status in a total of 28 patients. The New A1 regimen, which consists of cyclophosphamide, cisplatin, Adriamycin, and VP-16 has been administered in cases of less than 10 copies of N-myc, whereas the A3 regimen, consisting of a higher dose of cyclophosphamide, cisplatin, Adriamycin, and VP-16, has been administered in cases of more than 10 copies of N-myc. The survival rate was then compared between the old regimens and the new regimens.

RESULTS

The 3-year survival rate (61.5%) for patients treated by the new regimens was significantly higher than that (32.7%) for patients treated by the old regimens (P <.01). Regarding the 24 cases of more than 10 copies of N-myc, the 3-year survival rate (35.9%) of the 13 patients treated by the A3 regimen was higher than that (0%) of the 11 patients treated by the old regimens (P <.05). However, in the 19 stage IV patients treated by the new regimens, the 3-year survival rate (11.1%) of the 9 cases of more than 10 copies was significantly lower than that (77.8%) of the 10 cases of less than 10 copies of N-myc (P <.01).

CONCLUSIONS

These results suggest that high-dose combined chemotherapy based in part on the N-myc amplification status significantly improved the prognosis of patients with advanced neuroblastoma. However, stage IV patients with N-myc amplification still require a more effective treatment modality.

Down-regulation of CD98 in melphalan-resistant myeloma cells with reduced drug uptake

Although melphalan has been used as a therapeutic reagent for multiple myeloma, many patients become refractory. To elucidate the mechanism of resistance to melphalan, we generated a melphalan-resistant myeloma cell line, KHM-11(EMS), by treating a parental line, KHM-11, with a mutagen, ethylmethanesulfonate. KHM-11(EMS) is 55 times more resistant to melphalan. gamma-Glutamylcysteine synthetase, P-glycoprotein, multidrug-resistance-associated protein, lung-resistance-related protein and the Bcl-2 family of proteins were not responsible for the drug resistance in KHM-11(EMS). Intracellular incorporation of melphalan to myeloma cells was determined by using [(14)C]-labeled melphalan. Accumulation of melphalan in KHM-11(EMS) was 43% of KHM-11, while the efflux rates were comparable in both cell lines. The uptake of melphalan was inhibited by the addition of L-phenylalanine, indicating that melphalan is incorporated through the L-phenylalanine transporter as reported previously. Expression of CD98, which was recently cloned as an L-phenylalanine transporter, was 6-fold decreased in KHM-11(EMS), suggesting that CD98 may be correlated with the incorporation of melphalan. CD98 expression and incorporation of melphalan were analyzed in fresh purified myeloma cells from 5 patients. All myeloma cells from 4 cases expressed CD98 at a high level and incorporated melphalan. However, tumor cells from 1 case expressed CD98 at low levels and did not incorporate melphalan. Taken together, reduced melphalan uptake could be responsible for the drug resistance in KHM-11(EMS), and down-regulation of CD98 may be related to this phenomenon. Further investigation of the correlation between impaired drug uptake and down-regulation of CD98 in myeloma cells should be important to understand the mechanism of resistance to melphalan.

Establishment and characterization of a CD95 (Fas/Apo-1)-negative myeloma cell line

Although expression of CD95 (Fas/Apo-1) on myeloma cells has been reported, its significance is not clearly understood. We established a myeloma cell line, KHM-11ad (11ad), from a parental cell line, KHM-11, by collecting cells adhered to a plastic dish. KHM-11 cells have been reported to be positive for CD45 and CD95 (Fas/Apo1), and negative for a myelomonocytic antigen, CD13. Interestingly, CD95 was not detected in 11ad. Expression of CD45 was also significantly decreased in 11ad cells while expression of CD13 was detected in these cells. The growth rate of 11ad cells was 1.7 times lower than that of KHM-11 cells. Analysis of adhesion molecules showed that expression of VLA4 and CD44 was significantly suppressed in 11ad. The IC50 of melphalan (L-PAM) for 11ad cells was 50 times higher than that for KHM-11, indicating that 11ad is significantly refractory to L-PAM than KHM-11 cells. Induction of apoptosis by doxorubicin and cycloheximide was suppressed in 11ad cells compared with those in KHM-11 cells. Western blot analysis for Bcl-2 family of proteins showed that Bax was expressed at a 2.2 times lower level in 11ad cells than in KHM-11 cells while there was no difference in expression of Bcl-2, Bcl-Xs nor Bcl-XL. These results suggest that CD95-negative myeloma cells may have characteristics as follows: (1) slow proliferation; (2) low sensitivity to apoptosis; (3) low expression of VLA4, CD44 and Bax. Although these intraclonal variations were based on the findings of cell lines, these may reflect similar variations in vivo. The 11ad line may be a suitable model for analyzing intraclonal variation of myeloma cells.

Induction of endothelial nitric-oxide synthase in rat brain astrocytes by systemic lipopolysaccharide treatment

In the brain, three isoforms of nitric oxide (NO) synthase (NOS), namely neuronal NOS (nNOS, NOS1), inducible NOS (iNOS, NOS2), and endothelial NOS (eNOS, NOS3), have been implicated in biological roles such as neurotransmission, neurotoxicity, immune function, and blood vessel regulation, each isoform exhibiting in part overlapping roles. Previous studies showed that iNOS is induced in the brain by systemic treatment with lipopolysaccharide (LPS), a Gram-negative bacteria-derived stimulant of the innate immune system. Here we found that eNOS mRNA is induced in the rat brain by intraperitoneal injection of LPS of a smaller amount than that required for induction of iNOS mRNA. The induction of eNOS mRNA was followed by an increase in eNOS protein. Immunohistochemical analysis revealed that eNOS is located in astrocytes of both gray and white matters as well as in blood vessels. Induction of eNOS in response to a low dose of LPS, together with its localization in major components of the blood-brain barrier, suggests that brain eNOS is involved in early pathophysiologic response against systemic infection before iNOS is induced with progression of the infection.

Expression of citrulline-nitric oxide cycle in lipopolysaccharide and cytokine-stimulated rat astroglioma C6 cells

Nitric oxide (NO) is involved in many physiological and pathological processes in the brain. NO is synthesized from arginine by nitric oxide synthase (NOS), with citrulline generated as a by-product of the reaction. Thus, citrulline can by recycled to arginine by argininosuccinate synthetase (AS) and argininosuccinate lyase (AL) via the citrulline-NO cycle. Rat astroglioma C6 cells were treated with bacterial lipopolysaccharide (LPS), interferon-gamma (IFNgamma) and tumor necrosis factor-alpha, and the expression of the enzymes of the citrulline-NO cycle was investigated by RNA blot and immunoblot analyses. NO production from arginine and citrulline was also assessed. iNOS mRNA and protein were induced 6-12 h after stimulation with LPS and cytokines and decreased at 24 h. AS mRNA increased up to 12 h and decreased at 24 h. AS protein increased gradually up to 48 h. On the other hand, AL mRNA remained unchanged by stimulation. NO production from arginine was enhanced by the treatment with LPS and cytokines. NO production was also observed when arginine was replaced by citrulline. These results indicate that NO production is enhanced in LPS- and cytokine-stimulated C6 cells due to induction of iNOS and that the citrulline-arginine recycling is important for NO production.

Expression of inducible nitric oxide synthase and enzymes of arginine metabolism in Fusarium kyushuense-exposed mouse lung

Expression of inducible nitric oxide (NO) synthase (iNOS) and related enzymes of arginine metabolism in the mouse lung exposed to filamentous fungus Fusarium kyushuense was studied by RNA blot, immunoblot, and histological analyses. When mice were exposed intranasally to the fungi only once, no induction of iNOS mRNA was observed. However, when the animals were infected again 6 days after the first exposure, iNOS mRNA was induced, reached a maximum 12-24 h after the exposure, and decreased to an undetectable level at 48 h. mRNAs for cationic amino acid transporter-2 (CAT2) and argininosuccinate synthetase were induced gradually, reached a maximum at 24 h, and decreased at 48 h. Arginase II mRNA increased at 24 h and decreased markedly at 48 h. On the other hand, arginase I mRNA started to increase at 24 h and reached to a much higher level at 48 h. Ornithine decarboxylase and ornithine aminotransferase mRNAs were also induced. Immunoblot analysis showed that iNOS, argininosuccinate synthetase, and arginase I and II proteins were induced with similar kinetics as those of their respective mRNAs. In histological examination, fungal elements were observed in the bronchoalveolar lumen at 3-6 h, decreased at 12 h, and almost disappeared at 48 h. Small granuloma appeared 3 h after the infection and their size increased with time. These results suggest that NO is produced in the mouse lung in response to F. kyushuense exposure and that the NO production is regulated by CAT2, the citrulline-NO cycle, and arginase isoforms. Enhanced synthesis of polyamines and proline (and thus collagen) is also suggested.

Regulation of the genes for arginase isoforms and related enzymes in mouse macrophages by lipopolysaccharide

Arginase exists in two isoforms, the hepatic (arginase I) and extrahepatic types (arginase II). Arginase I is markedly induced in rat peritoneal macrophages and rat tissues in vivo by bacterial lipopolysaccharide (LPS). In contrast, both arginase I and arginase II are induced in LPS-activated mouse peritoneal macrophages. In the present study, expression of arginase isoforms and related enzymes was studied in mouse tissues in vivo and in peritoneal macrophages with RNA blot and immunoblot analyses and enzyme assay. When mice were injected intraperitoneally with LPS, inducible nitric oxide synthase (iNOS) and arginase II were induced early in the lung and spleen. mRNAs for argininosuccinate synthase (AS) and ornithine decarboxylase (ODC) were also induced early. In comparison, arginase I was induced later in the lung. Early induction of iNOS, arginase II, AS, ODC, and cationic amino acid transporter 2 and late induction of arginase I were observed in LPS-activated peritoneal macrophages. These results indicate that the genes for the two arginase isoforms are regulated differentially. Possible roles of the arginase isoforms in the regulation of nitric oxide production and in polyamine synthesis are discussed.

Detection of inducible nitric oxide synthase (iNOS) mRNA by RT-PCR in ATL patients and HTLV-I infected cell lines: clinical features and apoptosis by NOS inhibitor

Various tumors have been reported to express an inducible form of nitric oxide synthase (iNOS), and nitric oxide (NO) may affect the clinicopathological features of these tumors. Previously, Burkitt's lymphoma and Epstein-Barr virus (EBV)-infected cells were shown to express iNOS constitutively at a low level. We analyzed iNOS expression by the reverse transcriptase-polymerase reaction method (RT-PCR) in eight HTLV-I-infected cell lines (five were ATL-derived lines and there were in vitro transformed lines), nine ATL patients (three were chronic, two were acute, and four were lymphoma type), and an HTLV-I-negative T cell line (CEM). In four ATL derived and in all three in vitro transformed cell lines, iNOS was expressed constitutively, but it was not expressed in CEM cells. Four out of nine ATL patients also showed iNOS expression. The expression of iNOS was found in all subtypes of ATL. Three of four iNOS-positive patients had infiltration of ATL cells to organs such as skin, lung, or liver. In NOS inhibitor (NG-monomethyl-L-arginine: L-NMMA)-containing medium, an iNOS-positive ATL cell line (K3T) showed growth inhibition and DNA ladder. Although only a limited number of patients was analyzed, our results suggest that NO may be involved in the invasive character of ATL cells. The NOS inhibitor can induce apoptosis in an ATL cell line, as it does in EBV-infected cell lines.

Analysis of 1,992 patients with anorectal malformations over the past two decades in Japan. Steering Committee of Japanese Study Group of Anorectal Anomalies

BACKGROUND/PURPOSE

This report describes the results of a group study of the Japanese Study Group of Anorectal Anomolies (JSGA) to determine the relative incidence of specific types of anorectal anomaly in Japan, and includes discussion of rectourethral fistula regarding the relationship between the levels of the fistula and blind end of the rectum, low type deformity, rare types, and associated anomalies.

METHODS

A total of 1,992 patients (1,183 boys and 809 girls) registered from 1976 to 1995 were analyzed.

RESULTS

High-type deformities accounted for 26.0% of cases, intermediate 10.7%, low 57.2%, miscellaneous 4.5% and unclassified 1.8%. The most frequent deformity was male anocutaneous fistula (n = 364), followed by male rectourethral fistula (n = 333), and female anovestibular fistula (n = 241). There were 42 rectovesical fistulas in boys and 93 rectocloacal fistulas in girls. Covered anus complete occurred at the same frequency (10.1% of low deformities) as covered anal stenosis. In rectourethral fistula, the blind end of the rectum lay at or above the level of the P-C line in 40.3% of cases, at or above the M line in 39.6% and at the vicinity of the I line in 20.2%, respectively. There was no parallel relationship between the site of the fistula opening and the level of the rectal pouch. The overall incidence of patients having one or more associated anomalies was 45.2%: 70.6% in high deformity, 60.7% in intermediate, and 31.3% in low. The rate of association of Down's syndrome with deformities without fistula (40.3%) was significantly higher than with deformities with fistula (0.3%).

CONCLUSIONS

Rectovesical fistula and covered anus complete were not infrequent deformities in this series. We consider that at least 20% of rectourethral fistula should be categorized as intermediate or low deformity from the viewpoint of the position of the rectal pouch. A significant preponderance of Down's syndrome in the deformities without fistula suggests that further investigation of associated anomalies in comparision with other congenital diseases may provide insights into the pathogenesis of anorectal malformation in the field of molecular genetics.

Expression of arginase II and related enzymes in the rat small intestine and kidney

Arginase, which catalyzes the conversion of arginine to urea and ornithine, and consists of a liver-type (arginase I) and a non-hepatic type (arginase II). Arginine is also used for the synthesis of nitric oxide and creatine phosphate, while ornithine is used for the synthesis of polyamines and proline, and thus collagen. Arginase II mRNA and protein are abundant in the intestine (most abundant in the jejunum and less abundant in the ileum, duodenum, and colon) and kidney of the rat. In the kidney, the levels of arginase II mRNA do not change appreciably from 0 to 8 weeks of age. In contrast, arginase II mRNA and protein in the small intestine are not detectable at birth, appear at 3 weeks of age, the weaning period, and their levels increase up to 8 weeks. On the other hand, mRNAs for ornithine aminotransferase (OAT), ornithine decarboxylase, and ornithine carbamoyltransferase (OCT) are present at birth and their levels do not change much during development. Arginase II is elevated in response to a combination of bacterial lipopolysaccharide, dibutyryl cAMP, and dexamethasone in the kidney, but is not affected by these treatments in the small intestine. Immunohistochemical analysis of arginase II, OAT, and OCT in the jejunum revealed their co-localization in absorptive epithelial cells. These results show that the arginase II gene is regulated differentially in the small intestine and kidney, and suggest different roles of the enzyme in these two tissues. The co-localization of arginase II and the three ornithine-utilizing enzymes in the small intestine suggests that the enzyme is involved in the synthesis of proline, polyamines, and/or citrulline in this tissue.

Expression of PRAD1/cyclin D1 in plasma cell malignancy: incidence and prognostic aspects

We analysed PRAD1/cyclin D1 expression in 20 patients with plasma cell malignancy by Northern analysis. 6/17 multiple myeloma patients and 3/3 plasma cell leukaemia patients showed PRAD1/cyclin D1 expression. This incidence appeared to be higher than the expected incidence based on previous studies. Southern analysis did not show rearrangement of the bcl-1 region. Although there was no statistical difference, the PRAD1/cyclin D1 negative group showed a 1-year survival of 81.8%, 3-year survival of 45.5% and 5-year survival of 22.7%, and those for the PRAD1/cyclin D1 positive group were 63.5%, 16.9% and 16.9%, respectively. Further study is required to determine whether PRAD1/cyclin D1 expression is a prognostic factor.

Establishment of a monoclonal antibody to human myeloma cell: relation to chemotherapy and extramedullar infiltration

Resistance of myeloma cells to melphalan (L-PAM) is a serious problem. To investigate mechanisms of drug resistance, we generated a monoclonal antibody, clone O3, to melphalan-resistant myeloma cells, KHM-11R. Western blot analysis showed that molecular weight of O3 antigen was approximately 90 kDa. Expression of O3 antigen was approximately two times higher in KHM-11R than in parental melphalan sensitive cell line, KHM-11. O3 was preferentially expressed in plasma cell, B-cell, and monocytic cell lines, but not in T-cell lines. Analysis of bone marrow samples from myeloma patients revealed that 13 of 23 samples expressed O3 antigen at various levels, and that O3 antigen expression in patients correlate with preceding chemotherapy, advanced clinical stage and extramedullar invasion of myeloma cells. Furthermore, patients expressing O3 antigen at the time of diagnosis tended to have poor prognosis. The investigation of O3 antigen in myeloma cells will be useful to reveal the pathophysiology of extramedullar invasion and the mechanism of cell killing by melphalan.

Expression of Bcl-2 family of proteins in fresh myeloma cells

Members of the Bcl-2 family of proteins, Bcl-2, Bcl-X(L), Bcl-Xs and Bax, are considered to play important roles in the regulation of apoptosis and drug resistance. To understand the significance of these proteins in fresh human myeloma cells, expression of Bcl-2 family of proteins was analyzed by Western blotting in 17 cases with multiple myeloma (MM) and three cases with plasma cell leukemia (PCL). Bcl-2 and Bcl-X(L) were found in 12 and nine samples, respectively. All PCL cases showed co-expression of Bcl-2 and Bcl-X(L). Analysis of MM cases showed that Bcl-2 was preferentially expressed in samples from cases with early clinical stage while Bcl-X(L) tended to be expressed in samples from cases at advanced clinical stage. Bcl-X(L) was significantly expressed in tumor cells from cases with extramedullar lesions. There was no correlation between the expression levels of Bcl-2 or Bcl-X(L) and preceding chemotherapy. Expression of Bax was found in only one patient who had pleural effusion caused by invasion of myeloma cells and a high serum LDH level. Survival analysis revealed that there was no statistical significance in expression of Bcl-2 or Bcl-X(L) although Bcl-X(L) tended to be expressed in cases with poor prognosis. These findings indicate that expression of Bcl-2 family of proteins is heterogeneously regulated in fresh myeloma cells. Expression of Bcl-X(L) and Bcl-2 may correlate with extramedullar invasion and early stage of the disease, respectively. Absence of Bax in myeloma cells may contribute to low sensitivity of myeloma cells to anti-cancer agents since Bax is reported to mediate cytotoxicity of some anti-cancer drugs.

Immunohistochemical localization of arginase II and other enzymes of arginine metabolism in rat kidney and liver

Arginine is a precursor for the synthesis of urea, polyamines, creatine phosphate, nitric oxide and proteins. It is synthesized from ornithine by argininosuccinate synthetase and argininosuccinate lyase and is degraded by arginase, which consists of a liver-type (arginase I) and a non-hepatic type (arginase II). Recently, cDNAs for human and rat arginase II have been isolated. In this study, immunocytochemical analysis showed that human arginase II expressed in COS-7 cells was localized in the mitochondria. Arginase II mRNA was abundant in the rat small intestine and kidney. In the kidney, argininosuccinate synthetase and lyase were immunostained in the cortex, intensely in proximal tubules and much less intensely in distal tubules. In contrast, arginase II was stained intensely in the outer stripes of the outer medulla, presumably in the proximal straight tubules, and in a subpopulation of the proximal tubules in the cortex. Immunostaining of serial sections of the kidney showed that argininosuccinate synthetase and arginase II were colocalized in a subpopulation of proximal tubules in the cortex, whereas only the synthetase, but not arginase II, was present in another subpopulation of proximal tubules. In the liver, all the enzymes of the urea cycle, i.e. carbamylphosphate synthetase I, ornithine transcarbamylase, argininosuccinate synthetase and lyase and arginase I, showed similar zonation patterns with staining more intense in periportal hepatocytes than in pericentral hepatocytes, although zonation of ornithine transcarbamylase was much less prominent. The implications of these results are discussed.

Dictyostelium TRFA homologous to yeast Ssn6 is required for normal growth and early development

The TPR (tetratricopeptide repeat) family became widespread during evolution, having been found from bacteria to mammals. By means of restriction enzyme-mediated integration, we have identified a Dictyostelium gene (trfA) highly homologous to a Saccharomyces cerevisiae gene encoding a TPR protein, Ssn6 (Cyc8), which functions as a global transcriptional repressor for diverse genes. The deduced amino acid sequence of the Dictyostelium gene product, TRFA, contains 10 consecutive TPR units as well as Gln repeats, Asn repeats, and a region rich in Glu, Lys, Ser, and Thr. The sequences of some of the 10 TPR units in TRFA are more than 70% identical to the corresponding units in Ssn6. The trfA- cells produced smooth plaques on a bacterial lawn and failed to aggregate normally when starved on a plain agar plate. Individual trfA- cells also failed to correctly respond to cAMP, although the adenylyl cyclase of trfA- cells was expressed upon starvation and activated by stimulation with cAMP as in the wild-type cells. When cultured in a rich medium in suspension, they grew more slowly and stopped growing at a lower density than the wild-type cells. Furthermore, they divided into cells of various sizes and tended to be much smaller than the wild-type cells. These pleiotropic defects of the trfA- cells suggest the possibility that Dictyostelium TRFA may regulate the transcription of diverse genes required for normal growth and early development.

Evaluation of hair root analysis for acute phencyclidine poisoning and behavior of phencyclidine metabolites in rat hair root

We evaluated the usefulness of hair root analysis to diagnose acute phencyclidine (PCP) poisoning. Male rats were i.p. administered acute poisonous doses (80, 100 and 120 mg/kg) of PCP hydrochloride and the hair roots were plucked out with hair nippers at certain times after administration. The hair root samples were extracted with methanol/HCl. After evaporation of the solvent, the residue was derivatized with N,O-bis(trimethylsilyl) acetamide and analyzed with GC/MS. PCP was detected at high concentrations (up to 181.7 ng/mg) from all samples. The peak concentrations at every dose were observed at 6 h. The concentrations of PCP in the rat hair roots increased dose-dependently in the range of the doses. 1-(1-Phenylcyclohexyl)-4-hydroxypiperidine (PCHP) and trans-1-phenyl-1(4'-hydroxypiperidino)-4-cyclohexanol (t-PCPdiol) were also detected from 5 and 15 min to 48 h after administration, respectively. It is concluded that hair root is a useful specimen for the diagnosis of acute PCP poisoning because PCP, PCHP and t-PCPdiol are detected very soon after administration and a large amount of them is retained in hair root for a long time. PCHP was found from the early stage in hair roots and its concentration was higher than that of t-PCPdiol for 6 h. However, the concentration of t-PCPdiol became higher than that of PCHP after 6 h. These phenomena could be explained by the time lag of production of the primary (PCHP) and the secondary metabolite (PCPdiol).

A novel Dictyostelium discoideum gene required for cAMP-dependent cell aggregation

Using a method of random insertional mutagenesis called REMI (restriction enzyme-mediated integration), we isolated two mutant strains of Dictyostelium discoideum with a defect in cAMP-dependent cell aggregation. On bacterial lawns, both of the cells formed large and smooth plaques. When starved in a non-nutrient medium, they became elongated and extended pseudopods very frequently like starved wild type cells. However, they never formed streams toward an aggregation center. Genomic DNA fragments flanking the sites of insertion of the REMI tag were rescued from the mutant cells. The fragments contained one common open reading frame encoding a protein of 1148 amino acid residues. The protein's sequence is homologous to those of two hypothetical proteins of S. cerevisiae and S. pombe.

Multiple myeloma associated with serum amino acid disturbance and high output cardiac failure

We experienced a plasma cell leukemia (PCL) patient complicated with high output cardiac failure (HOCF), proved as his elevated cardiac index and pulmonary artery wedge pressure and decreased systemic vascular resistance index in a hemodynamic study. We found no possible causes of HOCF. Interestingly, HOCF was improved as PCL responded to intensive chemotherapy. On the other hand, he showed consciousness disturbance, and had frequent attacks of generalized seizure. His electroencephalogram showed slow waves, and a spike and wave complex. Hyperammonemia and abnormal amino acid distribution were also found. This abnormal serum amino acid distribution, especially elevated glycine level, was different from that seen in chronic liver failure, and he had no hepatic disease. After intensive chemotherapy, the serum ammonia level and glycine level decreased. In this patient, PCL seemed to be responsible for HOCF, hyperammonemia, and abnormal amino acid distribution. We experienced two more cases of multiple myeloma (MM) with HOCF, hyperammonemia, abnormal serum amino acid distribution, and consciousness disturbance of unknown origin. Those two cases showed slow waves in the electroencephalogram. Improvement was seen in their HOCF, hyperammonemia, and abnormal amino acid levels after chemotherapy. The possibility of MM as a cause of HOCF is discussed.

Regulation of the urea cycle enzyme genes in nitric oxide synthesis

Nitric oxide (NO) is synthesized from arginine by nitric-oxide synthase (NOS), and citrulline that is generated can be recycled to arginine by argininosuccinate synthase (AS) and argininosuccinate lyase (AL). Rats were injected with bacterial lipopolysaccharide (LPS) and expression of the inducible isoform of NOS (iNOS), AS and AL was analysed. In RNA blot analysis, iNOS mRNA was induced by LPS in the lung, heart, liver and spleen, and less strongly in the skeletal muscle and testis. AS and AL mRNAs were induced in the lung and spleen. Kinetic studies showed that iNOS mRNA increased rapidly in both spleen and lung, reached a maximum 2-5 h after the treatment, and decreased thereafter. On the other hand, AS mRNA increased more slowly and reached a maximum in 6-12 h (by about 10-fold in the spleen and 2-fold in the lung). AL mRNA in the spleen and lung increased slowly and remained high up to 24 h. In immunohistochemical analysis, macrophages in the spleen that were negative for iNOS and AS before LPS treatment were strongly positive for both iNOS and AS after this treatment. As iNOS, AS and AL were co-induced in rat tissues and cells, citrulline-arginine recycling seems to be important in NO synthesis under the conditions of stimulation. Arginine is a common substrate of NOS and arginase. Rat peritoneal macrophages were cultured in the presence of LPS and expression of iNOS and livertype arginase (arginase I) was analysed. mRNAs for iNOS and arginase I were induced by LPS in a dose-dependent manner. iNOS mRNA appeared 2 h after LPS treatment and increased up to a near-maximum at 8-12 h. On the other hand, arginase I mRNA began to increase after 4 h with a lag time and reached a maximum at 12 h. Immunoblot analysis showed that iNOS and arginase I proteins were also induced. Induction of iNOS and arginase I mRNAs were also observed in LPS-injected rats in vivo. Thus, arginase I appears to have an important role in downregulating NO synthesis in murine macrophages by decreasing the availability of arginine. A cDNA for human arginase II, an arginase isozyme, was isolated. A polypeptide of 354 amino acid residues including the putative NH2-terminal presequence for mitochondrial import was predicted. It was 59% identical with arginase I. mRNA for human arginase II was present in the kidney and other tissues but was not detected in the liver. Arginase II mRNA was co-induced with iNOS mRNA in murine macrophage-like RAW 264.7 cells by LPS. This induction was enhanced by dexamethasone and dibutyrul cAMP, and was prevented by interferon-gamma. These results indicate that NO synthesis is regulated by arginine-synthesizing and -degrading enzymes in a complicated manner.

Hyperdiploid myeloma cell as an indicator of poor prognosis and drug refractoriness

Although almost 40% of patients with multiple myeloma respond to initial chemotherapy, myeloma with no response to initial chemotherapy remains a serious problem. To understand the characteristics of drug-refractoriness of myeloma, fresh tumor cells from 13 untreated myeloma patients were fixed and stained with anti-human immunoglobulins and propidium iodide for subsequent flow cytometric analysis of DNA content. More than 10% of myeloma cells were hyperdiploid in eight cases (hyperdiploid + cases) while less than 10% of myeloma cells were hyperdiploid in five cases (hyperdiploid - cases). The proportion of hyperdiploid cells among all myeloma cells was highly correlated with incidence of myeloma cells with morphologically abnormal nuclei such as those with multiple-nuclei or convoluted nuclei (P = 0.001). Among the eight hyperdiploid + cases, two (2/8) showed good response to subsequent chemotherapy while four of five hyperdiploid - cases (4/5) responded well. Cases with poor response had more hyperdiploid myeloma cells (average 25.7% of all myeloma cells) than sensitive cases (average 6.8%), suggesting a contribution of hyperdiploid myeloma cells to primary drug resistance (P = 0.065). The 3 year survival rate of hyperdiploid+cases was 0% while that of the control group was 41.9%. These results suggest that myeloma cells with abnormal nuclear morphology may show hyperdiploidy and poor response to chemotherapy.

Acetylcholinesterase (ACE) staining shows the abnormal innervation of a pulled-through rectum in a case of repaired anorectal malformation

Abnormal innervation of the anorectum was noted in relation to anal incontinence in a case of repaired high-type anorectal malformation (ARM). A ten-year-old boy presented with anal incontinence after reconstructive surgery of ARM with a recto-urethral fistula. An anorectal manometrical examination revealed both an adequate tonus of the anal sphincter muscles and the absence of rectoanal reflex relaxation. And a barium enema showed a narrow region in the rectosigmoid colon, which was similar to that of Hirschsprung's disease (HD). Furthermore, an acetylcholinesterase (ACE) histochemical study of the rectal suction biopsies revealed an increased number of ACE-positive nerve fibers in the lamina propria mucosae and muscularis mucosae of the pulled-through colon. At the same time, however, some ganglia cells were also observed in the submucosa of the affected rectosigmoid colon and these cells could not be found in HD. Although the mechanism by which the abnormally innervated parasympathetic nerve fibers arose in the pulled-through colon remains unclear, this neuronal abnormality is considered to be the cause of anal incontinence in this case.

Coinduction of nitric-oxide synthase and arginase I in cultured rat peritoneal macrophages and rat tissues in vivo by lipopolysaccharide

Nitric oxide is synthesized by nitric-oxide synthase from arginine, a common substrate of arginase. Rat peritoneal macrophages were cultured in the presence of bacterial lipopolysaccharide (LPS), and expression of the inducible isoform of nitric-oxide synthase (iNOS) and liver-type arginase (arginase I) was analyzed. mRNAs for iNOS and arginase I were induced by LPS in a dose-dependent manner. iNOS mRNA appeared 2 h after LPS treatment and increased to a near maximum at 8-12 h. On the other hand, arginase I mRNA that was undetectable prior to the treatment began to increase after 4 h with a lag time and reached a maximum at 12 h. Immunoblot analysis showed that iNOS and arginase I proteins were also induced. mRNA for arginase II, an arginase isozyme, was not detected in the LPS-activated peritoneal cells. mRNA for CCAAT/enhancer-binding protein beta (C/EBPbeta), a transactivator of the arginase I gene, was also induced, and the induction was more rapid than that of arginase I mRNA. Changes in iNOS and arginase I mRNAs were also examined in LPS-injected rats in vivo. iNOS mRNA increased rapidly in the lung and spleen, reached a maximum 2-6 h after the LPS treatment, and decreased thereafter. Arginase I mRNA was induced markedly and more slowly in both tissues, reaching a maximum in 12 h. Thus, arginase I appears to have an important role in down-regulating nitric oxide synthesis in murine macrophages by decreasing the availability of arginine, and the induction of arginase I is mediated by C/EBPbeta.

Molecular cloning of cDNA for nonhepatic mitochondrial arginase (arginase II) and comparison of its induction with nitric oxide synthase in a murine macrophage-like cell line

Arginase exists in two isoforms. Liver-type arginase (arginase I) is expressed almost exclusively in the liver and catalyzes the last step of urea synthesis, whereas the nonhepatic type (arginase II) is expressed in extrahepatic tissues. Arginase II has been proposed to play a role in down-regulation of nitric oxide synthesis. A cDNA for human arginase II was isolated. A polypeptide of 354 amino acid residues including the putative NH2-terminal presequence for mitochondrial import was predicted. It was 59% identical with arginase I. The arginase II precursor synthesized in vitro was imported into isolated mitochondria and proteolytically processed. mRNA for human arginase II was present in the kidney and other tissues, but was not detected in the liver. Arginase II mRNA was coinduced with nitric oxide synthase mRNA in murine macrophage-like RAW 264.7 cells by lipopolysaccharide. This induction was enhanced by dexamethasone and dibutyryl cAMP, and was prevented by interferon-gamma. Possible roles of arginase II in NO synthesis are discussed.

Interspecies reactivities of anti-human macrophage monoclonal antibodies to various animal species

We examined interspecies reactivities of eight anti-human monocyte/macrophage monoclonal antibodies (MAbs), Am-3K, PM-2K, X4, X14, Ber-MAC3, GHI/61, EBM/11, and KP1, with various animal tissues including rats, guinea pigs, rabbits, cats, dogs, goats, pigs, bovines, horses, and monkeys. All MAbs recognized monkey macrophages. Pig macrophages were detected by most MAbs except for EBM/11 and KP1. Of the eight antibodies, AM-3K showed the widest interspecies reactivity. It reacted with macrophages of all animal species examined, except for rats. Western blot analysis revealed a similarity in the antigens recognized by AM-3K among guinea pigs, rabbits, and humans. Other anti-human MAbs demonstrated distinct reactive patterns against macrophages in animals. The immunostaining patterns of all of these MAbs in animal tissues were similar to those found in humans, although some MAbs, such as AM-3K, EBM/11, and X4, displayed more restricted reactivity in animals than in humans. These results indicate that some anti-human monocyte/macrophage MAbs are also available for immunohistochemical detection of monocyte/macrophages in animal tissues. Among them, AM-3K is considered to be the most useful MAb for identifying macrophages in various tissues of animals.

Management of traumatic pancreatic pseudocysts in children

Eight children with pancreatic injuries after blunt abdominal trauma are presented. One patient with pancreatitis without complications was treated successfully with medication; seven (87.5%) developed pseudocysts, which resolved spontaneously with conservative treatment in four cases (57.1%). Non-resolving pseudocysts in 3 patients finally required surgical intervention. Pseudocysts that resolve spontaneously and those that require surgical intervention can be distinguished. The two groups showed different time sequences in both serum amylase values and pseudocyst size. Analyses of these clinical data revealed three factors with significant predictive value. On the basis of these findings, a new management strategy for traumatic pancreatic pseudocysts in children is proposed. The cyst is likely to resolve spontaneously in cases showing any two or more of the following factors: (1) cyst presentation after day 6; (2) maximum serum amylase below 1,600 IU/l; and (3) serum amylase below 600 IU/l on day 20. However, early surgical intervention is required in the presence of two or more of the following: (1) cyst presentation before day 4; (2) maximum serum amylase above 1,900 IU/l; or (3) serum amylase above 1,200 IU/l on day 20.

Urachal remnants

Although urachal remnants rarely are observed clinically, they often give rise to a number of problems such as fatal infection and late malignant changes. Therefore, a total assessment of the disease with a particular focus on embryology, anatomy, and clinical symptoms, as well as the most advisable treatment, is called for. The authors report on 33 previously experienced cases and discuss the problems involved in both the diagnosis and treatment of these anomalies.