Planar catechin increases bone mass by regulating differentiation of osteoclasts in mice

OBJECTIVES

While catechins have been reported to exhibit potential to benefit osteoporosis patients, the effects of planar catechin (PCat), synthesized during the development of drugs for Alzheimer's disease, have not been clearly elucidated. Here, we examined the effects of PCat on mouse bone metabolism both in vivo and in vitro.

METHODS

Six week old female mice were orally administered PCat (30 mg/kg) every other day for four weeks, and their femurs were analyzed using micro-computed tomography imaging. Osteoclasts and osteoblasts were collected from mice and cultured with PCat. Subsequently, osteoclast formation and differentiation and osteoblast differentiation were observed.

RESULTS

Mice orally administered PCat displayed significantly increased femur bone mass compared to the control group. Quantitative polymerase chain reaction findings indicated that PCat addition to osteoclast progenitor cultures suppressed osteoclast formation and decreased osteoclast marker expression without affecting the proliferative potential of the osteoclast progenitor cells. Addition of PCat to osteoblast cultures increased osteoblast marker expression.

CONCLUSIONS

PCat inhibits osteoclast differentiation and promotes osteoblast differentiation, resulting in increased bone mass in mice. These results suggest that PCat administration is a promising treatment option for conditions associated with bone loss, including osteoporosis.

Abnormal bone regeneration induced by FK506 in medaka fin revealed by in vivo imaging

OBJECTIVES

Bone tissue in bony fish demonstrates a remarkable ability to regenerate, particularly evident following induction of extensive bone defects, such as fin amputation. This regenerative capacity has been reported to be promoted by the immunosuppressant FK506, yet its precise effects on bone cells during fin regeneration remains insufficiently elucidated. This study aims to investigate the effects of FK506 treatment on bone morphology, osteoblasts, and osteoclasts in the bony fin rays of osterix promoter-DsRed/TRAP promoter-EGFP double transgenic (Tg) medaka.

METHODS

The caudal fin of double Tg medaka was amputated, followed by a 20-day treatment with FK506 (1.0 μg/ml) to observe its effects on fin regeneration. Additionally, the regenerated caudal fin area underwent evaluation using genetic analysis and cell proliferation assays.

RESULTS

FK506 treatment significantly increased osterix-positive osteoblast formation, resulting in both a significantly longer fin length and fewer joints in the bony fin rays formed during fin regeneration. Notably, TRAP-positive osteoclast formation and bone resorption were observed to occur primarily during the latter stages of fin regeneration. Furthermore, while the expression levels of osteoblast-related genes in the regenerated area remained unchanged following FK506 treatment, a heightened cell proliferation was observed at the tip of the fin.

CONCLUSIONS

Our findings suggest that treatment with FK506 promotes bone regeneration by increasing the number of osteoblasts in the amputated area of the fin. However, long-term treatment disrupts regular bone metabolism by inducing abnormal osteoclast formation.

Tacrolimus, FK506, promotes bone formation in bone defect mouse model

OBJECTIVES

Some studies have reported that tacrolimus (FK506), an immunosuppressant, may have positive effects on bone formation. However, the precise effects of FK506 on bone repair or osteoblasts remain inadequately elucidated, and limited research has explored the outcomes of its use in an in vivo mouse model. This study aims to examine the effects of FK506 on bone repair and osteoblast functions using bone defect and BMP-2-induced ectopic ossification mouse models, as well as cultured primary mouse osteoblasts treated with FK506.

METHODS

We established mouse models of femur bone defect and BMP-2-induced ectopic ossification to evaluate the effect of FK506 on new bone formation, respectively. Additionally, primary mouse osteoblasts were cultured with FK506 and examined for gene expressions related to osteoblast differentiation.

RESULTS

While FK506 promoted the repair of bone defect areas in the femur of the bone defect mouse model, it also led to widespread abnormal bone formation outside the intended area. Additionally, following the implantation of a collagen sponge containing BMP-2 into mouse muscle tissue, FK506 was found to promote ectopic ossification and enhance BMP-2-induced osteoblast differentiation in vitro. Our findings also revealed that FK506 increased the number of immature osteoblasts in the absence of BMP-2 without affecting osteoblast differentiation. Furthermore, direct effects were observed, reducing the ability of osteoblasts to support osteoclastogenesis.

CONCLUSIONS

These results indicate that FK506 increases new bone formation during bone repair and influences the proliferation of immature osteoblasts, as well as osteoblast-supported osteoclastogenesis.

Behavior of intracellular lipid droplets during cell division in HuH7 hepatoma cells

Intracellular lipid droplets (LDs) are ubiquitous organelles found in many cell types. During mitosis, membranous organelles, including mitochondria, are divided into small pieces and transferred to daughter cells; however, the process of LD transfer to daughter cells is not fully elucidated. Herein, we investigated the behavior of LDs during mitosis in HuH7 human hepatoma cells. While fragments of the Golgi apparatus were scattered in the cytosol during mitosis, intracellular LDs retained their size and spherical morphology as they translocated to the two daughter cells. LDs were initially distributed throughout the cell during prophase but positioned outside the spindle in metaphase, aligning at the far sides of the centrioles. A similar distribution of LDs during mitosis was observed in another hepatocarcinoma HepG2 cells. When the spindle was disrupted by nocodazole treatment or never in mitosis gene A-related kinase 2A knockdown, LDs were localized in the area outside the chromosomes, suggesting that spindle formation is not necessary for LD localization at metaphase. The amount of major LD protein perilipin 2 reduced while LDs were enriched in perilipin 3 during mitosis, indicating the potential alteration of LD protein composition. Conclusively, the behavior of LDs during mitosis is distinct from that of other organelles in hepatocytes.

Effects of anti-RANKL antibodies administered to pregnant mice on bone and tooth development in neonates

OBJECTIVES

This study examined how the anti-bone resorptive agent denosumab, which comprises anti-receptor activator of nuclear factor kappa B ligand (anti-RANKL) monoclonal antibodies, administered during pregnancy affected neonatal development. Anti-RANKL antibodies, which are known to bind to mouse RANKL and inhibit osteoclast formation, were administered to pregnant mice. Following this, the survival, growth, bone mineralization, and tooth development of their neonates were analyzed.

METHODS

Anti-RANKL antibodies (5 mg/kg) were injected into pregnant mice on day 17 of gestation. After parturition, their neonatal offspring underwent microcomputed tomography at 24 h and at 2, 4, and 6 weeks after birth. Three-dimensional bone and teeth images were subjected to histological analysis.

RESULTS

Approximately 70% of the neonatal mice born to mice who received anti-RANKL antibodies died within 6 weeks after birth. These mice had a significantly lower body weight and significantly higher bone mass compared with the control group. Furthermore, delayed tooth eruption and abnormal tooth morphology (eruption length, enamel surface, and cusps) were observed. Conversely, while the tooth germ shape and mothers against decapentaplegic homolog 1/5/8 expression remained unchanged at 24 h after birth in the neonatal mice born to mice that received anti-RANKL antibodies, osteoclasts were not formed.

CONCLUSIONS

These results suggest that anti-RANKL antibodies administered to mice in the late stage of pregnancy results in adverse events in their neonatal offspring. Thus, it is speculated that administering denosumab to pregnant humans will affect fetal development and growth after birth.

Effects of Anti-RANKL Antibody and Zoledronic Acid on Periapical Lesion Development in Mice

INTRODUCTION

Anti-resorptive drugs are widely used to treat osteoporosis and other systemic bone diseases, though their efficacy for local bone resorption following localized inflammation has not been fully elucidated. We examined the effects of an anti-receptor activator of nuclear factor-κB ligand (RANKL) antibody and the bisphosphonate zoledronic acid (ZOL) on periapical lesion (PL) development in mice.

METHODS

Dental pulps of lower first molars in mice were removed, with the exposed dental pulp chambers left open to the oral environment to induce apical periodontitis. An anti-RANKL antibody or ZOL was intraperitoneally injected once per week until postoperative day 21, then micro-computed tomography and histological analyses were performed.

RESULTS

PL enlargement was inhibited by both the anti-RANKL antibody and ZOL in a dose-dependent manner and reduction of inflammatory cell infiltration in apical tissues inhibited periapical bone resorption. The anti-RANKL antibody decreased the number of osteoclasts in periapical tissues, while ZOL suppressed periapical bone resorption with osteoclast numbers maintained. While administration of each of the anti-resorptive drugs increased femoral bone mass, femoral bone mineral density in the PL group was lower as compared to the sham-operated group.

CONCLUSIONS

These results suggest that an anti-resorptive drug administered systemically is distributed to areas of local inflammation in the jaw and can prevent PL development.

Neural crest-derived cells possess differentiation potential to keratinocytes in the process of wound healing

Neural crest-derived cells (NCDCs), which exist as neural crest cells during the fetal stage and differentiate into palate cells, also exist in adult palate tissues, though with unknown roles. In the present study, NCDCs were labeled with EGFP derived from P0-Cre/CAG-CAT-EGFP (P0-EGFP) double transgenic mice, then their function in palate mucosa wound healing was analyzed. As a palate wound healing model, left-side palate mucosa of P0-EGFP mice was resected, and stem cell markers and keratinocyte markers were detected in healed areas. NCDCs were extracted from normal palate mucosa and precultured with stem cell media for 14 days, then were differentiated into keratinocytes or osteoblasts to analyze pluripotency. The wound healing process started with marginal mucosal regeneration on day two and the entire wound area was lined by regenerated mucosa with EGFP-positive cells (NCDCs) on day 28. EGFP-positive cells comprised approximately 60% of cells in healed oral mucosa, and 65% of those expressed stem cell markers (Sca-1⁺, PDGFRα⁺) and 30% expressed a keratinocyte marker (CK13⁺). In tests of cultured palate mucosa cells, approximately 70% of EGFP-positive cells expressed stem cell markers (Sca-1⁺, PDGFRα⁺). Furthermore, under differentiation inducing conditions, cultured EGFP-positive cells were successfully induced to differentiate into keratinocytes and osteoblasts. We concluded that NCDCs exist in adult palate tissues as stem cells and have potential to differentiate into various cell types during the wound healing process.

Findings from recent studies by the Japan Aerospace Exploration Agency examining musculoskeletal atrophy in space and on Earth

The musculoskeletal system provides the body with correct posture, support, stability, and mobility. It is composed of the bones, muscles, cartilage, tendons, ligaments, joints, and other connective tissues. Without effective countermeasures, prolonged spaceflight under microgravity results in marked muscle and bone atrophy. The molecular and physiological mechanisms of this atrophy under unloaded conditions are gradually being revealed through spaceflight experiments conducted by the Japan Aerospace Exploration Agency using a variety of model organisms, including both aquatic and terrestrial animals, and terrestrial experiments conducted under the Living in Space project of the Japan Ministry of Education, Culture, Sports, Science, and Technology. Increasing our knowledge in this field will lead not only to an understanding of how to prevent muscle and bone atrophy in humans undergoing long-term space voyages but also to an understanding of countermeasures against age-related locomotive syndrome in the elderly.

Novel gene Merlot inhibits differentiation and promotes apoptosis of osteoclasts

Extended osteoclast longevity is deeply involved in the pathogenesis of bone diseases such as osteoporosis and rheumatoid arthritis, though the mechanisms that determine osteoclast lifespan are not fully understood. Here we present findings indicating that the newly characterized gene Merlot, which encodes a highly conserved yet uncharacterized protein in vertebrates, is an important regulator for termination of osteoclastogenesis via induction of apoptosis. Mice lacking Merlot exhibited low bone mass due to increased osteoclast and bone resorption. Furthermore, osteoclast precursors overexpressing Merlot failed to differentiate into mature osteoclasts, while Merlot deficiency led to hyper-nucleation and prolonged survival of osteoclasts, accompanied by sustained nuclear localization of nuclear factor of activated T cell c1 (NFATc1) and derepression of glycogen synthase kinase-3β (GSK3β) activity, known to regulate NFATc1 activity and induce apoptosis. Merlot-deficient osteoclasts were found to represent suppression of caspase-3-mediated apoptosis and Merlot deficiency caused transcriptional downregulation of a proapoptotic cascade, including Bax, Bak, Noxa, and Bim, as well as the executor caspase members Casp-3, -6, and -7, and upregulation of anti-apoptotic Bcl2, resulting in a low apoptotic threshold. Thus, Merlot regulates osteoclast lifespan by inhibition of differentiation and simultaneous induction of apoptosis via regulation of the NFATc1-GSK3β axis.

Effects of N-methyl-d-aspartate receptor antagonist MK-801 (dizocilpine) on bone homeostasis in mice

OBJECTIVES

To gain insight into the role of the N-methyl-d-aspartate (NMDA) receptor in bone metabolism by examining the effects of its noncompetitive antagonist, MK-801 (dizocilpine), on bone homeostasis and bone healing in mice.

METHODS

MK-801 (2.5 mg/kg) or saline (in control groups) was intravenously administered to healthy mice and mice with bone-defects daily for seven to 14 days. Bone defects were artificially created in femurs using a drill and reamer. Following euthanasia, bones were extracted and processed for microcomputed tomography (μCT) and histological analyses. The effects of MK-801 on osteoclast differentiation by bone marrow macrophages (BMMs) were examined in vitro. mRNA expressionlevels of Grin3b levels were also examined using reverse-transcription polymerase chain reaction (RT-PCR).

RESULTS

Bone volume was significantly decreased in mice administered MK-801 for 14 days. Additionally, the number of osteoclasts was reduced, while number of osteoblasts and rate of bone formation were increased in these mice. MK-801 inhibited osteoclast differentiation dose-dependently in vitro. RT-PCR findings suggested expression of Grin3b, a subunit of the NMDA receptor, in BMMs. During the healing process of artificially created defects in femurs, no significant differences were found between the control and MK-801-treated groups, indicating no stimulatory or inhibitory effects by MK-801 administration.

CONCLUSIONS

These results indicate that blockade of the NMDA receptor by MK-801 administration affects bone metabolism but not the healing process of artificial bone defects.

Myelination during fracture healing in vivo in myelin protein zero (p0) transgenic medaka line

During the fracture healing process, osteoblasts and osteoclasts, as well as the nervous system are known to play important roles for signaling in the body. Glia cells contribute to the healing process by myelination, which can increase the speed of signals transmitted between neurons. However, the behavior of myelinating cells at a fracture site remains unclear. We developed a myelin protein zero (mpz)-EGFP transgenic medaka line for tracing myelinating cells. Mpz-enhanced green fluorescence protein (EGFP)-positive (mpz⁺) cells are driven by the 2.9-kb promoter of the medaka mpz gene, which is distributed throughout the nervous system, such as the brain, spinal cord, lateral line, and peripheral nerves. In the caudal fin region, mpz⁺ cells were found localized parallel with the fin ray (bone) in the adult stage. mpz⁺ cells were not distributed with fli-DsRed positive (fli⁺) blood vessels, but with some nerve fibers, and were dyed with the anti-acetylated tubulin antibody. We then fractured one side of the caudal lepidotrichia in a caudal fin of mpz-EGFP medaka and found a unique phenomenon, in that mpz⁺ cells were accumulated at 1 bone away from the fracture site. This mpz⁺ cell accumulation phenomenon started from 4 days after fracture of the proximal bone. Thereafter, mpz⁺ cells became elongated from the proximal bone to the distal bone and finally showed a crosslink connection crossing the fracture site to the distal bone at 28 days after fracture. Finally, the effects of rapamycin, known as a mTOR inhibitor, on myelination was examined. Rapamycin treatment of mpz-EGFP/osterix-DsRed double transgenic medaka inhibited not only the crosslink connection of mpz⁺ cells but also osterix⁺ osteoblast accumulation at the fracture site, accompanied with a fracture healing defect. These findings indicated that mTOR signaling plays important roles in bone formation and neural networking during fracture healing. Taken together, the present results are the first to show the dynamics of myelinating cells in vivo.

Effects of lipid metabolism on mouse incisor dentinogenesis

Tooth formation can be affected by various factors, such as oral disease, drug administration, and systemic illness, as well as internal conditions including dentin formation. Dyslipidemia is an important lifestyle disease, though the relationship of aberrant lipid metabolism with tooth formation has not been clarified. This study was performed to examine the effects of dyslipidemia on tooth formation and tooth development. Dyslipidemia was induced in mice by giving a high-fat diet (HFD) for 12 weeks. Additionally, LDL receptor-deficient (Ldlr^−/−) strain mice were used to analyze the effects of dyslipidemia and lipid metabolism in greater detail. In the HFD-fed mice, incisor elongation was decreased and pulp was significantly narrowed, while histological findings revealed disappearance of predentin. In Ldlr^−/− mice fed regular chow, incisor elongation showed a decreasing trend and pulp a narrowing trend, while predentin changes were unclear. Serum lipid levels were increased in the HFD-fed wild-type (WT) mice, while Ldlr^−/− mice given the HFD showed the greatest increase. These results show important effects of lipid metabolism, especially via the LDL receptor, on tooth homeostasis maintenance. In addition, they suggest a different mechanism for WT and Ldlr^−/− mice, though the LDL receptor pathway may not be the only factor involved.

Biological Effects of Anti-RANKL Antibody and Zoledronic Acid on Growth and Tooth Eruption in Growing Mice

The anti-bone resorptive drugs denosumab, an anti-human-RANKL antibody, and zoledronic acid (ZOL), a nitrogen-containing bisphosphonate, have recently been applied for treatment of pediatric patients with bone diseases, though details regarding their effects in growing children have yet to be fully elucidated. In the present study, we administered these anti-resorptive drugs to mice from the age of 1 week and continued once-weekly injections for a total of 7 times. Mice that received the anti-RANKL antibody displayed normal growth and tooth eruption, though osteopetrotic bone volume gain in long and alveolar bones was noted, while there were nearly no osteoclasts and a normal of number osteoblasts observed. In contrast, ZOL significantly delayed body growth, tooth root formation, and tooth eruption, with increased osteoclast and decreased osteoblast numbers. These findings suggest regulation of tooth eruption via osteoblast differentiation by some types of anti-resorptive drugs.

Roles of monocarboxylate transporter subtypes in promotion and suppression of osteoclast differentiation and survival on bone

Monocarboxylate transporters (MCTs) provide transmembrane transport of monocarboxylates such as lactate and pyruvate. The present results showed that α-cyano-4-hydroxycinnamic acid (CHC), an inhibitor of MCTs, promoted osteoclast differentiation from macrophages at lower concentrations (0.1–0.3 mM) and suppressed that at a higher concentration (1.0 mM). On the other hand, CHC reduced the number of mature osteoclasts on the surface of dentin in a concentration-dependent manner. Additionally, macrophages and osteoclasts were found to express the Mct1, Mct2, and Mct4 genes, with Mct1 and Mct4 expression higher in macrophages, and that of Mct2 higher in osteoclasts. Although Mct1 gene knockdown in macrophages enhanced osteoclast formation induced by RANKL, Mct2 gene knockdown suppressed that. Finally, Mct2 gene silencing in mature osteoclasts decreased their number and, thereby, bone resorption. These results suggest that MCT1 is a negative regulator and MCT2 a positive regulator of osteoclast differentiation, while MCT2 is required for bone resorption by osteoclasts.

A Delphinidin-Enriched Maqui Berry Extract Improves Bone Metabolism and Protects against Bone Loss in Osteopenic Mouse Models

In our previous investigation, delphinidin, one of the most abundant anthocyanins found in vegetables and berry fruits, had been shown to inhibit osteoclasts and prevent bone loss in mouse models of osteoporosis. In the present study, we investigated whether a delphinidin glycoside-enriched maqui berry extract (MBE, Delphinol^®) exhibits beneficial effects on bone metabolism both in vitro and in vivo. MBE stimulated the osteoblastic differentiation of MC3T3-E1 cells, as indicated by enhanced mineralized nodule formation, and increased alkaline phosphatase activity, through the upregulation of bone morphogenetic protein 2 (Bmp2), runt-related transcription factor 2 (Runx2), osterix (Osx), osteocalcin (Ocn), and matrix extracellular phosphoglycoprotein (Mepe) mRNA expression. Immunostaining and immunoprecipitation assays demonstrated that MBE suppressed NF-κB transnucleation through acting as a superoxide anion/peroxynitrite scavenger in MC3T3-E1 cells. Simultaneously, MBE inhibited both osteoclastogenesis in primary bone marrow macrophages and pit formation by maturated osteoclasts on dentine slices. Microcomputed tomography (micro-CT) and bone histomorphometry analyses of femurs demonstrated that the daily ingestion of MBE significantly increased BV/TV (ratio of bone volume to tissue volume), Tb.Th (trabecular thickness), Tb.N (trabecular number), N.Nd/N.Tm (node to terminus ratio), OV/TV (ratio of osteoid volume to tissue volume), BFR/TV (bone formation rate per tissue volume), and significantly decreased Tb.Sp (trabecular separation), ES/BS (ratio of eroded surface to bone surface) and N.Oc/BS (number of osteoclast per unit of bone surface), compared to vehicle controls in osteopenic mouse models. These findings suggest that MBE can be a promising natural agent for the prevention of bone loss in osteopenic conditions by not only inhibiting bone resorption, but also stimulating bone formation.

TGFβ-2 signaling is essential for osteoblast migration and differentiation during fracture healing in medaka fish

TGFβ is known as a canonical coupling factor based on its effects on bone formation and bone resorption. There are 3 different isoforms of it related to bone metabolism in mammals. TGFβ function in vivo is complicated, and each isoform shows a different function. Since TGFβs are secreted during inflammation accompanied by the release of latent TGFβ from inside of the bones where they are stored in the extracellular matrix, TGFβ function is potentially related to fracture healing. Although a few reports examined the TGFβ expression during fracture healing, the function of TGFβ in this process is poorly understood. To investigate TGFβ function during fracture healing in vivo, we used the fracture healing model of the medaka fish, which enabled us to observe the behavior and function of living cells in response to a bone-specific injury. RNA in-situ hybridization analysis showed that only tgfβ-2 of the 4 TGFβ isoforms in medaka was expressed in the bone-forming region. To examine the TGFβ-2 function for bone formation by osteoblasts, we used a medaka transgenic line, Tg (type X collagen: GFP); and the results revealed that type X collagen-positive immature osteoblasts migrated to the fracture site and differentiated to osterix-positive osteoblasts. However, only a few type X collagen-positive osteoblasts exhibited BrdU incorporation after the fracture. Then we inhibited TGFβ signaling by using a chemical TGFβ receptor kinase inhibitor (SB431542), and demonstrated that inhibition of TGFβ strongly impaired osteoblast migration and differentiation. In addition, this TGFβ inhibitor reduced the RANKL expression and caused a delay of osteoclast differentiation. Our findings thus demonstrated that TGFβ-2 functioned specifically during fracture healing to stimulate the migration of osteoblasts as well as the differentiation of osteoblasts and osteoclasts.

Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station

To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment (“Medaka Osteoclast”) was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation–reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation.

Efficacy of the Mirasol pathogen reduction technology system against severe fever with thrombocytopenia syndrome virus (SFTSV)

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tickborne virus in the Bunyaviridae family. This virus has recently been found in China, Japan and Korea. The risk of transfusion-transmitted SFTSV infection (TTI-SFTSV) is a concern because person-to-person transmission resulting from contact with SFTSV-contaminated blood has been reported. Therefore, we investigated the efficacy of the Mirasol pathogen reduction technology (PRT) system for inactivating SFTSV in vitro. The Mirasol PRT system achieved a > 4.11 log10 reduction value (LRV) for SFTSV. In conclusion, we showed that the Mirasol PRT system could potentially be used to reduce the risk of TTI-SFTSV.

Osteoclasts in bone modeling, as revealed by in vivo imaging, are essential for organogenesis in fish

Bone modeling is the central system controlling the formation of bone including bone growth and shape in early development, in which bone is continuously resorbed by osteoclasts and formed by osteoblasts. However, this system has not been well documented, because it is difficult to trace osteoclasts and osteoblasts in vivo during development. Here we showed the important role of osteoclasts in organogenesis by establishing osteoclast-specific transgenic medaka lines and by using a zebrafish osteoclast-deficient line. Using in vivo imaging of osteoclasts in the transgenic medaka carrying an enhanced GFP (EGFP) or DsRed reporter gene driven by the medaka TRAP (Tartrate-Resistant Acid Phosphatase) or Cathepsin K promoter, respectively, we examined the maturation and migration of osteoclasts. Our results showed that mononuclear or multinucleated osteoclasts in the vertebral body were specifically localized at the inside of the neural and hemal arches, but not at the vertebral centrum. Furthermore, transmission electron microscopic (TEM) analyses revealed that osteoclasts were flat-shaped multinucleated cells, suggesting that osteoclasts initially differentiate from TRAP-positive mononuclear cells residing around bone. The zebrafish panther mutant lacks a functional c-fms (receptor for macrophage colony-stimulating factor) gene crucial for osteoclast proliferation and differentiation and thus has a low number of osteoclasts. Analysis of this mutant revealed deformities in both its neural and hemal arches, which resulted in abnormal development of the neural tube and blood vessels located inside these arches. Our results provide the first demonstration that bone resorption during bone modeling is essential for proper development of neural and vascular systems associated with fish vertebrae.

Expression of marker genes during otolith development in medaka

Little is known about the genes and processes involved in the development of otoliths. In this study, we isolated the biomineralization-related genes otolin and chondromodulin-1 (chm1) from medaka, and examined their spatiotemporal expression pattern as well as that of two other genes also related to biomineralization, i.e., sparc/osteonectin and type II collagen (col2a), during otic development in medaka. Our results demonstrated that all the tested genes were expressed in the otic vesicle, and that chm1 was exclusively expressed in the semicircular canal of the otic vesicle.

Screening of micro-organisms for decolorization of melanins produced by bluestain fungi

A total of 17 fungi and four bacteria were screened for their ability to decolorize melanin, using isolated extracellular melanin of the bluestain fungus Aureobasidium pullulans as substrate. On agar media, decolorization was observed by four fungal strains: Bjerkandera adusta VTT-D-99746, Galactomyces geotrichum VTT-D-84228, Trametes hirsuta VTT-D-95443 and Trametes versicolor VTT-D-99747. The four fungi were more efficient on nitrogen-limited medium than on complete medium. The melanin-decolorizing activity of G. geotrichum appeared to be located on the mycelium and could be liberated into the medium enzymatically.

Proper use of serum antibody titres against Epstein-Barr virus in nasopharyngeal carcinoma: IgA/virus capsid antigen for diagnosis and EBV-related nuclear antigen-2 for follow-up

Sera from patients with nasopharyngeal carcinoma (NPC) show high titres of IgA antibodies to Epstein-Barr viral capsid antigen (IgA/VCA). We reported previously that the serum titres for Epstein-Barr virus-related nuclear antigen-2 (EBNA2) correlated with NPC patients' prognosis. To investigate which is better for diagnosing NPC and predicting patient prognosis, the titration of serum IgA/VCA or EBNA2, we examined the same serum titres. Sixteen cases of NPC in which serum EBNA2 antibody titres had been tested, were investigated for the serum IgA/VCA antibody titres before and after radiation treatment. All NPC cases showed positive reactions with indirect immunofluorescence staining, and the median titre was 252. Twelve normal controls, 5 mesopharyngeal carcinoma patients, 4 hypopharyngeal carcinoma patients, 4 laryngeal carcinoma patients and 6 malignant lymphoma were also examined, but they showed negative or relatively low titres. A follow-up study revealed that IgA/VCA titres remained mostly stable. These results indicate a close relationship between IgA/VCA and NPC, however, prognosis correlated better with EBNA2 titres than with IgA/VCA titres.

Percutaneous brachytherapy for small-sized non-small cell lung cancer

A patient with a small-sized pulmonary adenocarcinoma was successfully treated by percutaneous high dose rate interstitial brachytherapy alone. The patient, who had an adenocarcinoma with 12-mm diameter in the lingular lobe of left lung, was judged to be inoperable because of poor pulmonary function due to emphysema and extensive pleural adhesion. The tumor was punctured with a 21-gauge fine applicator needle followed by the introduction of an iridium 192 (192Ir) radioactive source through the applicator needle using a remote afterloader. The tumor was irradiated for 225.1 s in one fraction. The tumor was in the inside of the iso-dose line of 40 Gy. The delivered doses calculated at nine reference points, which were 12.5 mm distant from the center of the tumor, distributed between 19.225 and 32.169 Gy, with a mean of 24.8 Gy. No apparent side effect including pneumothorax and hemoptysis was observed. The tumor shrank and showed no increment of the size for about 2 years.

Prognostic factors for patients with esophageal cancer treated with radiation therapy in PCS: a preliminary study

PURPOSE

We investigated the prognostic factors, with special reference to age, for esophageal cancer patients, who did not receive surgery but were treated with radiation in the context of a Patterns of Care Study (PCS) in Japan.

PATIENTS AND METHODS

The fifth PCS database format employed in the United States was used to collect information on 455 esophageal cancer patients by external audit. The data of patients who had not received surgery (n=252) were further selected and divided into two age groups, patients 75 years old or older (n=90) and patients younger than 75 years (n=162). Cox's proportional hazards model was used for the statistical analysis, with crude survival as the endpoint. Variables tested were age; Karnofsky performance status (KPS); history of pulmonary disease, cardiovascular disease, and diabetes; AJCC stage; external dose; treatment period; combination with chemotherapy; utilization of brachytherapy, and stratification of institutions.

RESULTS

Statistically significant prognostic factors for all patients in the non-surgery group were KPS p=.0001), stage (p=.0001), and utilization of brachytherapy (p=.0102). For younger patients, KPS (p=.0001), stage (p=.0007), external dose (p=.0001), and utilization of brachytherapy (p=.0034) were significant, and for the elderly, stage (p=.0001) and external dose (p=.0006).

CONCLUSION

Although this was a preliminary study, age was not a significant prognostic factor for esophageal cancer patients in the non-surgery group, and making the external dose more than 60 Gy appears to be effective for improving survival of elderly as well as younger patients.

Adjuvant radiotherapy after radical hysterectomy of the cervical cancer. Prognostic factors and complications

AIM

To investigate prognostic factors and complications after radical hysterectomy followed by postoperative radiotherapy for carcinoma of the uterine cervix.

PATIENTS AND METHODS

One hundred twenty-eight patients with T1b-2b carcinoma of the uterine cervix following radical hysterectomy with bilateral pelvic lymphadenectomy and postoperative radiation therapy were reviewed. Pathologic and treatment variables were assessed by multivariate analysis for local recurrence, distant metastases and cause specific survival.

RESULTS

The number of positive nodes (PN) in the pelvis was the strongest predictor of pelvic recurrence and distant metastases. These 2 failure patterns independently affect the cause specific survival. The 5-year cumulative local and distant failure were PN(0): 2% and 12%, PN(1-2): 23% and 25%, PN(2 <): 32% and 57%, respectively (p = 0.0029 and p = 0.0051). The 5-year cause specific survival rates were PN(0): 90%, PN(1-2): 59% and PN(2 <): 42% (p = 0.0001). The most common complication was lymphedema of the foot experienced by one-half of the patients (5-year: 42%, 10-year: 49%).

CONCLUSION

These results suggest that patients with pathologic T1b-T2b cervix cancer with pelvic lymph node metastases are at high risk of recurrence or metastases after radical hysterectomy with pelvic lymphadenectomy and postoperative irradiation.

[The state of the art: radiation therapy for non-small cell lung cancer]

The standard radiation schedule for non-small cell lung cancer is conventional fractionated 60-70 Gy/6-7 weeks in Japan, while a split-course or hypofractionated schedule is also used in some institutions in other countries. Hyperfractionated radiotherapy with/without chemotherapy is increasing while no definitive treatment schedule has been established as a standard treatment method. Dose escalation study by 3D-conformal radiotherapy is also an attempt at a breakthrough of radiotherapy in unresectable non-small cell lung cancer.

Radiation therapy for early glottic carcinoma (T1N0M0). The adverse effect of treatment interruption

PURPOSE

Clarification of the adverse effects of treatment interruption on the local control of early glottic carcinoma.

PATIENTS AND METHODS

From May 1982 through February 1992, 273 patients with early glottic carcinoma (T1N0M0) were treated at this department. Of 253 patients administered 60 Gy in 30 fractions 77 patients had no treatment interruption and treatment was completed within 6 weeks (group I), overall treatment time was prolonged for 176 patients: 141 patients 43 to 49 days (group II) and 35 patients 50 to 62 days (group III). Treatment was interrupted due to public holidays (156 cases), patients convenience (13 cases) and severe mucosal reactions (seven cases). The major reason was public holidays, 91% in group II and 80% in group III.

RESULTS

The 3-year recurrence-free survival rates were for group I 95%, group II 89% and group II 80%. Survivals for groups I and II, groups II and III and groups I and III were essentially the same. At 40 Gy tumor clearance was more than 50% in the 3-groups. For complete clearance cases at 40 Gy, recurrence-free survival was essentially the same for the 3 groups although for incomplete clearance cases, statistically significant difference for groups I and III (log-rank test p = 0.0004; Wilcoxon test p = 0.0004) and marginally significant difference for groups II and III (p = 0.0157, p = 0.0045) but no difference for groups I and II (p = 0.0669, p = 0.0853) were noted by adjusting the p-value.

CONCLUSION

Prolongation of overall treatment time and tumor clearance at 40 Gy appeared to be a factor of the local control.

High-dose rate intracavitary irradiation for carcinoma of the uterine cervix. The adverse effect of treatment prolongation

AIM

To investigate the adverse effect of treatment prolongation on the local control and survival of the cervical carcinoma of the uterus.

PATIENTS AND METHOD

Two hundred and sixteen patients with stage IIB and III cervical carcinoma treated with a combination of external radiation and high-dose rate (HDR) intracavitary irradiation between 1978 and 1989 were retrospectively studied. A multivariate analysis was used to determine the effect of treatment time on local control and survival.

RESULTS

Overall treatment time was the most highly significant factors for local control in the multivariate analysis (p = 0.0005). The 5-year cumulative relapse rates were significantly different with the treatment times 35 to 42 days: 9% versus 43 to 49 days: 19% versus 50 to 62 days: 42% (p = 0.001). The second most significant parameter was stage classification (p = 0.02). Concerning relapse-free survival, stage classification (p = 0.0001), overall treatment time (p = 0.0035) and hemoglobin level (p = 0.0174) were the 3 most important prognostic factors, although there was no relationship between treatment time and late complications.

CONCLUSION

These results suggest that prolongation of treatment time is associated with decreased local control and survival in patients treated with external radiation and HDR intracavitary irradiation.

Management for stage II glottic carcinoma: radiation therapy or surgery

AIM

To analyze the results of stage II glottic carcinoma treated with radiotherapy or surgery.

PATIENTS AND METHOD

One hundred thirty-four patients with squamous cell carcinoma of the T2N0M0 glottic carcinoma treated at the Osaka Medical Center for Cancer and Cardiovascular Diseases from 1979 through 1991 were reviewed. The 5-year disease-free survival and laryngeal preservation rate and prognostic factors were examined. Treatment was radiation therapy with salvage surgery for failure or surgery alone.

RESULTS

The 5-year disease-specific survival rate for the radiotherapy group was 100% and for the surgery group, 93% (p = 0.055). In the surgery group 5-year disease-specific survival rate for the subgroup of cord mobility was 94% and that of impaired cord mobility, 89% (p = 0.5354). Concerning laryngeal preservation the radiotherapy group showed better preservation rate than the surgery group in the subgroup of cord mobility, i.e., 41/51 (80%) versus 6/55 (11%) (p < 0.001) although significant difference was not observed in the lesion with impaired cord mobility, 2/5 versus 4/22 (p = 0.171).

CONCLUSION

We recommend radiation therapy for stage II glottic carcinoma with normal cord mobility, although further study is needed to improve the preservation rate of the larynx with keeping the disease-specific survival for the lesion with impaired cord mobility.

Radiation therapy for early glottic carcinoma (T1N0M0). The final results of prospective randomized study concerning radiation field

PURPOSE

To investigate the effect of radiation field on the local control of early glottic carcinoma by prospective randomized study.

PATIENTS AND METHODS

From May 1982 through February 1992, a total of 273 patients with early glottic carcinoma (T1N0M0) was treated at our department with a wedge filter technique using a shell to improve the dose distribution and immobilization during radiotherapy with 4 MV X-ray. Patients were randomly allocated to either treatment group A (radiation field size: 5 x 5 cm) or B (6 x 6 cm) using bilateral parallel opposed portals. Total radiation dose administered was 60 Gy in 30 fractions over a 6-week period.

RESULTS

The 5-year recurrence-free survival rates were 88% in groups A and B (no significant difference). Minor chronic complication such as persistent arytenoid edema lasting more than 6 months or benign polypoid lesion of vocal cord was more frequently observed in group B (23%) than in group A (17%) (p = 0.038) while acute mucosal reaction and skin reaction showed no significant differences.

CONCLUSION

A small field (5 x 5 cm) with an appropriate angle of wedge filter and shell fixing device is recommended to avoid adverse effect with keeping local control of early glottic carcinoma.

[Treatment of head and neck cancer: radiation therapy]

Radiation therapy is an effective modality for curative treatment with organ preservation, palliative treatment for pain control and combined/prophylactic treatment for local-regional control after surgery in head and neck cancer. For early lesions, 70-90% of local control may be expected in radiation therapy. However, some hurdles must be cleared with regard to advanced lesions. We reviewed the prospective randomized controlled trials (phase III trial) concerning adjuvant chemotherapy and multiple fractions per day of radiotherapy for advanced head and neck cancer. Adjuvant chemotherapy may be used in three ways in the treatment, i.e., induction therapy, concomitantly with radiotherapy and maintenance therapy. We reviewed the former two treatments because no "pure" phase III trial could be found in maintenance therapy after radiotherapy. As for multiple fractions per day of radiation therapy, the following definition is used. Hyperfractionation: Total dose is increased; dose per fraction is reduced; fractian number is increased,; overall time is relatively unchanged. Accelerated fractionation: Overall time is reduced; number of fraction total dose, and dose per fraction are either unchanged or somewhat reduced, depending on the extent of overall time reduction. Adjuvant chemotherapy combined with radiotherapy and multiple fractions per day of radiotherapy have been attempted to increase local-regional control and survival in a few randomized studies. However, these survival results were disappointing despite good local control. We need a more effective chemotherapy regime, fractionation schedule and also to clarify the indications for these treatments by analyzing the prognostic factors.

The complete nucleotide sequence of odontoglossum ringspot virus (Cy-1 strain) genomic RNA

The complete nucleotide sequence of the genomic RNA of odontoglossum ringspot virus Cy-1 strain (ORSV Cy-1) was determined using cloned cDNA. This sequence is 6611 nucleotides long containing four open reading frames, which correspond to 126 K, 183 K, 31 K, and 18 K proteins. Its genomic organization is similar to other tobamoviruses, TMV-V(vulgare), TMV-L (tomato strain), tobacco mild green mosaic virus (TMGMV) and cucumber green mottle mosaic virus (CGMMV). The 5' non-coding regions of ORSV Cy-1 is 62 nucleotides. The ORFs encoded a 126 K polypeptide and a 183 K read-through product in which helicase-sequence and polymerase-sequence motifs are found. The ORFs encoding the 126 K and 183 K proteins have 61% and 63% identities with those of TMV-V. The third ORF encoded a 31 K protein homologous to TMV cell-to-cell movement protein. It has 63% identities with that of TMV-V. The fourth ORF encoded an 18 K coat protein. The 5' non-coding region, which extends from base 1 to 62 has 2 G residues and a ribosome binding site (AUU). The 3' non-coding region, 414 nucleotides in length, is entirely different from that of other tobamoviruses.

Prophylactic irradiation of para-aortic lymph nodes in carcinoma of the uterine cervix. A prospective randomized study

PURPOSE

For assessment of the advantages and side effects of para-aortic lymph nodes irradiation under the evaluation by computer tomography, a prospective randomized study was started in 1986. The results for survival, local control and late complications are presented in the following.

PATIENTS AND METHODS

From November 1986 to October 1990, 93 patients with cervical carcinoma were randomly allocated for treatment with either pelvic irradiation (pelvic group) or pelvic plus para-aortic lymph nodes irradiation (para-aortic group). Thirty-six patients underwent external irradiation and intracavitary therapy (RT arm) and 57 patients, extended radical hysterectomy and external irradiation (OP-RT arm). Para-aortic lymph nodes irradiation delivered 45 Gy in 1.8 Gy per day for 5 days per week through anterior-posterior fields.

RESULTS

The 3-year cause specific survival rates were para-aortic group: 57% and pelvic group: 89% in RT arm group, and para-aortic group: 70% and pelvic group: 86% in OP-RT arm group. Differences for the 2 groups in each treatment arm were not significant. In pelvic failure, para-aortic lymph nodes metastases and distant metastases showed no statistically significant differences for the 2 groups in each treatment arm. In the para-aortic group, complications were more frequent than in the pelvic group (13/45 vs. 2/48, p < 0.025). As an enteric complication ileus was found in 7% (3/45) of the para-aortic group while 2% (1/48) in the pelvic group. Compression fractures of the lumber vertebral body were apparent in 9% (4/45) and 0%, respectively.

CONCLUSION

Routine para-aortic lymph nodes irradiation delivered through anterior-posterior fields for high risk patients with cervical carcinoma is of limited value occurring to the high incidence of late complications and this treatment fails to improve no survival rates.

[Radiation therapy for brain metastases from lung carcinoma: the second prospective randomized trial]

Since September 1980 we have been conducting a prospective randomized trial to determine the best treatment schedule for radiation therapy (XRT) of brain metastasis from lung carcinoma. The first trial (September 1980 to December 1984) used random allocation of two different time-dose radiotherapy schemes: 30 Gy/10 fractions/2 weeks versus 50 Gy/20 fr./4 wks. Treatment results showed no significant difference in neurological improvement or survival between the two arms or in lactate dehydrogenase (LDH) as the most important prognostic factor. The current study (January 1985 to April 1992) examined two sequential trials stratified according to the level of LDH and included 162 patients with brain metastasis from lung carcinoma. Whole brain doses were 30 Gy/10 fr./2 wks (group A, n = 46) or 50 Gy/20 fr./4 wks. (group B, n = 46) in the normal LDH group and 30 Gy/10 fr./2 wks (group C, n = 35) or 20 Gy/5 fr./1 wk. (group D, n = 35) in the high LDH group, while the treatment field was lessened to 30 Gy in group B if possible. The final results showed that 1) the most important prognostic factor as determined by Cox's multivariate analysis was also LDH in the second trial; 2) the incidence of acute side effects tended to depend upon a single dose, i.e., group A (3 Gy) 35% versus group B (2.5 Gy) 21% (p = 0.165), and group C (3 Gy) 23% versus group D (4 Gy) 46% (p = 0.044); 3) median survival time and 1-year survival rates were 5.4 months and 21% in group A, 4.8 months and 17% in group B; 3.4 months and 6% in group C; and 2.4 months and 4% in group D, respectively, and survival curves showed no statistically significant difference between the two treatment groups in each LDH group; 4) improvement in neurological function appeared to increase with total dosage escalation, i.e., 41% in group A versus 45% in group B, and 35% in group C versus 21% in group D (not significant). In conclusion, a short intensive course (30 Gy/10 fr./2 wks) is advantageous for XRT because of the short treatment time and minor acute toxicity in spite of stratification by the level of LDH.

A prospective randomized study concerning the point A dose in high-dose rate intracavitary therapy for carcinoma of the uterine cervix. The final results

PURPOSE

High-dose rate (HDR) remote afterloading intracavitary therapy has been recognized as an effective and safe treatment modality for carcinoma of the uterine cervix. Since 1983, a prospective randomized study was started in order to investigate the more advantageous treatment schedule with keeping the local control rate. This paper reports the final results in terms of survival, local control and complications.

PATIENTS AND METHODS

Between January 1983 and February 1989, a total of 165 patients with carcinoma of the uterine cervix was entered in a prospective randomized study concerning the point A dose of HDR therapy (6 Gy/fraction vs 7.5 Gy/fraction) and external irradiation dose at Department of Radiation Therapy, The Center for Adult Diseases, Osaka. UICC [20] stage distribution of patients was as follows: stage IA = 4, stage IB = 33, stage IIA = 18, stage IIB = 38, stage III = 57, stage IV = 15.

RESULTS

Overall 5-year cause specific survivals were as follows: stage IA = 100%, stage IB = 96%, stage IIA = 92%, stage IIB = 79%, stage III = 57%, stage IV = 27%. In each stage, 5-year survival rates in groups A and B were 100%, 93% in stage I, 82% and 85% in stage II, 62% and 52% in stage II and 22% and 31% in stage IV, respectively. There were no statistically significant differences among these survival curves in each stage. Five-year local failure rates were 16% in group A and 16% in group B (p = 0.9096), and corresponding distant failure rates were 23% in group A and 19% in group B (p = 0.2955). Moderate-to-severe complications requiring treatment (Kottmeier's grade 2 or more) were noted in 6 patients (7%) in group A and 6 patients (7%) in group B. All of the bladder and rectal complications needed medical treatment (Kottmeier's grade 2). Severe complications receiving surgery were noted in 4 patients (A: 1; B: 3), i.e., small intestine 3 and sigmoid colon 1 patient. Another 1 patient (A) was dead of ileus.

CONCLUSIONS

There were no statistically significant differences between 2 treatment schedules in survival rates, failure patterns and complications rates. This fact suggests that small number of fractions (7.5 Gy/fraction) may be advantageous because of short duration and a low load of treatment.

Long term follow-up results of high-dose rate remote afterloading intracavitary radiation therapy for carcinoma of the uterine cervix

PURPOSE

High-dose rate remote afterloading intracavitary radiation therapy (HDR) has been used as more safety system by the dose calculation using computer system before treatment and dose monitoring system using semiconductor dosimeter (ICD-5). This study shows our long-term follow-up results concerning survival, prognostic factor and late complications.

MATERIAL AND METHODS

Between August 1978 and December 1982, a total of 200 patients with carcinoma of the intact uterine cervix were treated using HDR. According to the staging system of UICC (1987), 8 patients were classified into Stage Ia, 22 Ib, 22 IIa, 53 IIb, 85 III, and 10 IV.

RESULTS

Cause specific five- and ten-year survival rates by Stage were 100%, 100% in Stage Ia, 90%, 90% in Stage Ib, 76%, 76% in Stage IIa, 86%, 84% in Stage IIb, 54%, 46% in Stage III and 20%, 20% in Stage IV, respectively. Significant prognostic factors by Cox's multivariate analysis were stage (p = 0.0001), the value of hemoglobin (p = 0.0005) and older age (p = 0.0114). Concerning stage classification the value of hemoglobin was the most important prognostic factor in Stage II (p = 0.032) and Stage III (p = 0.0015). Late complications requiring medical treatment after RALS developed in 24 patients (12%), i.e., rectum 14 (7), bladder 8 (4), small intestine 5 (3), sigmoid colon 1 (1). Severe complications requiring surgery were noted in 9 patients (5%).

CONCLUSION

HDR yields good results of survival with a low risk of severe side effects for the treatment of carcinoma of uterine cervix based on our long-term follow-up results.

Radiation therapy for brain metastases from lung carcinoma. Prospective randomized trial according to the level of lactate dehydrogenase

PURPOSE

Since September 1980 we have been conducting a prospective randomized trial to determine the best treatment schedule for radiation therapy (XRT) on brain metastasis from lung carcinoma. The first trial (September 1980 to December 1984) was randomly allocated by two different time-dose radiotherapy schemes, i.e., 30 Gy/ten fractions/two weeks versus 50 Gy/20 fractions/four weeks. Treatment results showed no significant difference in neurological improvement and survival between the two arms and lactate dehydrogenase (LDH) as the most important prognostic factor. The present study (January 1985 to April 1992) examines two sequential trials stratified by the level of LDH enrolled 162 patients with brain metastasis from lung carcinoma.

PATIENTS AND METHODS

Whole brain dose was selected for 30 Gy/ten fractions/two weeks (group A, n = 46) or 50 Gy/20 fractions/four weeks (group B, n = 46) in the group with normal LDH and 30 Gy/ten fractions/two weeks (group C, n = 35) or 20 Gy/five fractions/one week (group D, n = 35) in the group with high LDH, while the treatment fields were shrunk at 30 Gy in group B if possible.

RESULTS

The final results showed the facts that 1. the most important prognostic factor, according to Cox's multivariate analysis, was also the level of LDH in the second trial, 2. the incidence of acute side effects showed the trend toward depending upon a single dose, i.e., group A (3 Gy/fraction); 35% versus group B (2.5 Gy/fraction); 21% (p = 0.165) and group C (3 Gy/fraction); 23% versus group D (4 Gy/fraction); 45% (p = 0.044), 3. median survival time and one-year survival rates were 5.4 months and 21% in group A; 4.8 months and 17% in group B; 3.4 months and 6% in group C; and 2.4 months and 4% in group D, respectively, and survival curves showed no statistically significant difference between the two treatment groups in each LDH group, 4. improvement in neurologic function appeared to increase with total dosage escalation, i.e., 41% in group A versus 45% in group B and 35% in group C versus 21% in group D (p = 0.13).

CONCLUSION

A short course (30 Gy/ten fractions/two weeks) is an advantageous XRT because of the short treatment time for normal LDH and neurological improvement and minor toxicity for the high LDH group, while an optional treatment may be necessary for the selected patients.

Radiation therapy for early glottic carcinoma: indication for the wedge filter

From 1977 to the end of 1987, 244 patients with early glottic carcinoma (T1N0M0) were treated with radiation therapy. For 95 patients (group A), a styrofoam head holder and band were used to ensure immobilization during treatment without a wedge filter and for 149 patients (group B) a shell fixing devise and wedge filter were used. Total radiation dose administered was 50 to 70 Gy over a period of five to seven weeks with fields of 5 x 5 cm (group A) and 5 x 5 cm (group B1: n = 74) or 6 x 6 cm (group B2: n = 75). The five-year relapse-free survival (RFS) rates for group A and B were 85% and 90%, respectively, and RFS was essentially the same (p = 0.241). In group B, RFS was also basically the same for groups B1 and B2 (p = 0.78). According to tumor size, however, in patients with large T1a lesions (total length of one vocal cord) five-year RFS rates for groups A and B were 62% and 88%, respectively, and RFS was statistically significantly different (p = 0.003). Up to five years, seven patients (9%) of group A and 23 patients (17%) of group B showed minor chronic complication. As a minor chronic complication, arytenoid edema was found more frequently in group B (n = 15) than group A (n = 0). Eleven of these 15 cases were treated with large field (6 x 6 cm). For large T1a lesions of glottic carcinoma, a wedge filter was useful. A small field (5 x 5 cm) with an appropriate angle of wedge filter is recommended to avoid late arytenoid edema and achieve a more homogeneous dose distribution.

Radiation therapy of the nasopharyngeal carcinoma. Treatment results and prognostic factors

Between September 1977 and December 1989, 89 consecutive patients of nasopharyngeal carcinoma were treated with radiation therapy. The study comprised of 66 males and 23 females; their ages ranged from 17 to 80 years (mean 55 years). Five-year survival rates according to stage were as follows: stages I and II (n = 10), 90%; stage III (n = 10), 43%; stage IV (n = 69), 47%. The important prognostic factors for predicting poor prognostic in this series, which were shown by stepwise proportional hazard (Cox) model, were the level of lactate dehydrogenase (LDH) and neck node involvement. LDH level also influenced nodal failure (p = 0.0002) and distant metastasis (p = 0.006).

[Radiation therapy of nasopharyngeal carcinoma: treatment results and prognostic factors]

Between September 1977 and December 1989, 89 consecutive patients with nasopharyngeal carcinoma were treated with radiation therapy. The study included 66 men and 23 women whose ages ranged from 17 to 80 years (mean, 55 years). Five-year survival rates according to stage were as follows: Stage I + II (n = 10), 90%; Stage III (n = 10), 43%; Stage IV (n = 65), 47%. Important factors for predicting poor prognosis in this series, as were shown by the stepwise proportional hazard (Cox) model, were the level of lactate dehydrogenase (LDH) and neck node involvement (Ho's classification). LDH level also influenced nodal failure (p = 0.0002) and distant metastasis (p = 0.006).

Radiation therapy for larynx carcinoma: long-term results of stage I glottic carcinoma

From November 1977 through March 1982, 95 patients with early glottic carcinoma (T1N0M0) were treated with radiation therapy. Total radiation dose administered was 50 to 70 Gy over five to seven weeks period with fields of 5 x 5 cm2. Actuarial five- and ten-year survival rates were 81% and 76%, and five- and ten-year relapse free survival rates were 85% and 83%, respectively. Radiation failures were surgically salvaged in 93% (14/15) and ultimate locoregional control rate was 97% (92/95). The rate of voice preservation was 86% (82/95). As a minor chronic complication polypoid lesion and impaired mobility of vocal cord was found in 9% (seven cases) and 5% (four cases) of patients without local recurrence. We need long-term follow-up after radiation therapy for the locoregional control and keeping the quality of voice.

Replication of maize streak virus mutants in maize protoplasts: evidence for a movement protein

We have used protoplasts derived from a maize (Black Mexican Sweet) suspension culture to study the replication of maize streak virus (MSV) wild-type (wt) and mutant DNA genomes. Following inoculation with plasmids containing multimeric copies of MSV, both single-stranded (ss) and double-stranded MSV DNA forms were produced, in proportions relative to those seen in infected plants. The immunodetection of coat protein (PV2) and geminate particles confirmed that the protoplasts were able to support the entire multiplication cycle of MSV and therefore were suitable for the study of MSV gene function. Inoculation of protoplasts with V1 gene mutants which are unable to produce systemic infections in plants resulted in DNA replication and encapsidation indistinguishable from that obtained with wt constructs implicating the protein in virus movement. Computer analysis of the V1 protein (PV1) indicated a potential trans-membrane or membrane-embedded domain. Following inoculation of protoplasts with V2 mutants, ssDNA was not detected; the inability of these mutants to spread in plants may be due to a lack of ssDNA, PV2, or a combination of the two. The requirements for systemic infection of MSV are discussed.

[Indication and problems of radiation therapy of elderly patients with cancer]

The incidence of cancer and the patients treated with radiation therapy increased with age. Of 5778 patients treated with radiation therapy at the Center for Adult Diseases, Osaka, 37.5% are over 65, and 10.8% are over 75 years old. Older patients with cancer have a lower survival rate. Patients over the age of 75 with carcinoma of the pharynx, esophagus, lung, and uterine cervix have decreased survival compared with younger patients. However, for the patients with carcinoma of the larynx, age is not a determinant of prognosis. With respect to radiation therapy, it is not clear whether elderly patients differ from younger ones in responsiveness. However, a decreased tolerance for radiation therapy might be expected and under-dosing with radiation therapy may be more prevalent. More study of the optimal management of elderly patients with cancer is needed.

Radiation therapy for the esophageal carcinoma: external irradiation versus high-dose rate intraluminal irradiation

From September 1977 through December 1989, 149 patients with esophageal carcinoma were treated with external irradiation (EI) with or without high-dose rate intraluminal irradiation (HDRII) using remote afterloading system. Two-year relapse-free survival rates were 52% in sage I (n = 23), 24% in stage II (n = 61) and 19% in stage III (n = 65). Two-year survival rates were 66% in complete response (CR) group (n = 65) and 7 to 9% in non-CR group (n = 84). Concerning CR group external irradiation alone (mean +/- S. D.: 66.5 +/- 5.2 Gy) showed higher local control rate than EI (60.0 +/- 0.4 Gy) + HDRII (10 Gy) (30/38 versus 15/27, p = 0.044), especially in ulcerative type (17/19 versus 5/11, p = 0.009). This preliminary result suggests that HDRII is not effective for the local control of the ulcerative lesion as a boost therapy.

Incidence of other primary cancers in 1,569 patients with pharyngolaryngeal cancer and treated with radiation therapy

From January 1977 through December 1989, a total of 1,569 patients with pharyngolaryngeal cancer (oropharynx: 240, nasopharynx: 221, hypopharynx: 246, and larynx: 862) were treated at the Department of Radiology, Osaka University Hospital and the Department of Radiation Therapy, The Center for Adult Diseases, Osaka. The incidence of other primary cancers in these patients was investigated using the data base of radiation therapy combined with information from hospital-based and Osaka prefectural cancer registries. One hundred and seventy-six of the 1,569 patients (11%) had other primary cancers (oropharynx: 21%, nasopharynx: 7%, hypopharynx: 13%, and larynx: 9%). The time of development of other primary cancers in more than 50% of the cases ranged between one year before and one year after the diagnosis of primary pharyngolaryngeal cancer. The expected number of the second primary cancer was estimated by multiplying the age-sex specific incidence rates for Osaka residents with person-years at risk based on Osaka prefectural cancer registry data. The observed/expected (O/E) ratios were 3.17 (p less than 0.01) for oropharyngeal, 2.01 (p less than 0.01) for nasopharyngeal, 2.16 (p less than 0.01) for hypopharyngeal and 1.10 (n.s.) for laryngeal cancer. The most common sites of the second primary cancer in order of frequency were: the oral cavity and pharynx, esophagus and lung for oropharyngeal cancer, the oral cavity and pharynx for nasopharyngeal cancer, the oral cavity and pharynx and the esophagus for hypopharyngeal cancer and the oral cavity and pharynx, esophagus and lung for laryngeal cancer.

Radiation therapy for the supraclavicular lymph node metastasis after curative resection of the esophageal carcinoma

172 patients underwent curative resection for squamous cell carcinoma of the esophagus. The five-year actuarial survival rate was 38%. 21 of 27 patients who developed nodal metastasis of the supraclavicular lymph node were irradiated with a total dose of 40 to 70 Gy over four to seven weeks. This retrospective study showed the following results: 1. Complete response by radiation therapy was obtained 4/4 in tumor size within 2 cm, 7/10 in 2.1 to 5.0 cm with a total dose of 60 to 70 Gy, while 1/5 with a total dose of 40 to 56 Gy. 2. There were statistically significant differences of survival curves between multiple metastases and single metastasis of the supraclavicular lymph node (p less than 0.01).

Irradiated volume and arytenoid edema after radiotherapy for T1 glottic carcinoma

From May 1982 through December 1986, 116 T1 glottic carcinomas were treated with radiotherapy in a prospective randomized study to determine the effect of radiation field size. Patients were treated with a total dose of 60 Gy over six weeks using 4 MV X-ray, wedge filter and shell. Local control rates treated with a field size of 5 x 5 cm2 and 6 x 6 cm2 were 93% and 95%, respectively. Persistent laryngeal edema occurred in 4% of cases treated with 5 x 5 cm2 and 21% with 6 x 6 cm2 (p less than 0.02). The rate of late laryngeal edema was dependent upon the treatment volume. A larger treatment field yielded a higher minor complication rate without improvement of local control rate.