Long-term outcomes of 95 children with moderate aplastic anemia treated with horse antithymocyte globulin and cyclosporine

BACKGROUND

Currently, the standard management of moderate aplastic anemia (MAA) has not been well described, although the superiority of the combination of antithymocyte globulin (ATG) and cyclosporine (CyA) over CyA alone has been demonstrated in terms of hematological responses and failure-free survival (FFS).

PROCEDURE

We adopted this therapeutic strategy and treated 95 children with MAA who were enrolled in two consecutive prospective studies between October 1992 and August 2009.

RESULTS

For these patients, the 6-month response rate was 54.7% (complete response, 13.7%; partial response, 41.1%). There were no statistically significant differences in the overall response rates between the transfusion-dependent (48.8%, n = 41) and transfusion-independent groups (59.3%, n = 54; P = 0.4). Treatment failure was defined as the requirement of salvage treatment, and was observed in 52 patients. The 10-year FFS was 44.0% (95% confidence interval [CI], 32.9%-54.6%). Of the 22 patients who underwent a second immunosuppressive therapy (IST), 12 responded. Forty patients underwent hematopoietic stem cell transplantation as second- or third-line therapy and three died of complications. Consequently, the 10-year overall survival rate was 96.0% (95% CI, 88.0%-98.7%) with a median follow-up period of 103 months (range, 29-221 months).

CONCLUSIONS

Although current guidelines recommend only observation for patients with transfusion-independent MAA, the results of our study justify early intervention with ATG and CyA in those patients. A prospective randomized trial is warranted to clarify the risks and benefits of early intervention with IST and observation alone until progression to severe AA in patients with MAA.

A Pediatric Case of Metastatic Conventional Parosteal Osteosarcoma Treated With Multidrug Chemotherapy

Parosteal osteosarcoma (POS) is conventionally a low-grade sarcoma with limited metastatic potential; however, the tumor occasionally transforms into a high-grade dedifferentiated POS, which commonly metastasizes to distant organs. The present report describes a rare pediatric case of conventional POS with no dedifferentiated component yet had multiple pulmonary metastases at initial diagnosis. Following limb-sparing surgery and osteosarcoma-oriented neoadjuvant chemotherapy, the patient received total resection of pulmonary metastases. Despite no treatment for pulmonary recurrence 1 year after adjuvant chemotherapy, the patient is alive with stable disease 4 years and 6 months after the initial diagnosis.

Central nervous system recurrence of desmoplastic small round cell tumor following aggressive multimodal therapy: A case report

Patients with desmoplastic small round cell tumors (DSRCTs) have an extremely poor outcome despite the use of aggressive therapy. The current study presents the case of 16-year-old male with metastatic DSRCT, in which multimodal therapy, including intensive chemotherapies using frequent autologous stem cell support, gross resection of primary and metastatic lesions, and whole abdominopelvic intensity-modulated radiation therapy, was administered. Subsequent to these treatments, there was no evidence of active disease. However, cerebellar and pineal body lesions, and bone metastasis to the left humerus were detected 1 year and 2 months after the initial diagnosis. Combination chemotherapy with irinotecan and temozolomide was initially effective against the central nervous system (CNS) metastatic lesions; however, the patient succumbed due to progressive CNS disease after seven courses of combination chemotherapy. Additional studies are required to accumulate information regarding CNS recurrence of DSRCT.

Development of CMV retinitis in an antigenemia-negative infant after cord blood transplantation

A five-month-old male infant with familial hemophagocytic lymphohistiocytosis underwent cord blood transplantation using reduced-intensity conditioning. Methylprednisolone (mPSL) pulse administration was performed for marked pulmonary edema during the early phase of transplantation, followed by GVHD treatment with mPSL until day 100. CMV antigenemia was detected on days 27 and 55, but serum became negative with 2- to 3-week ganciclovir (GCV) treatment on both occasions. On day 120, ophthalmological findings included multiple bilateral white spots and a positive PCR study using anterior chamber fluid confirmed the diagnosis of CMV retinitis affecting both eyes, although CMV antigenemia was negative. Re-treatment with GCV had a minimal effect on the ophthalmological findings, while foscarnet administration markedly improved the retinitis and decreased the CMV-DNA level. Considering that a substantial proportion of patients develop CMV retinitis even when CMV antigenemia is not present, routine monitoring involving ophthalmological examinations should be conducted for hematopoietic transplant patients, especially infants, who cannot complain of ocular symptoms.

[Epileptic encephalopathy associated with human herpes virus 6 (HHV-6) encephalitis after the second cord blood transplantation in a patient with pediatric acute lymphoblastic leukemia]

The incidence of HHV-6 encephalitis during hematopoietic stem cell transplantation (HSCT) in children is thought to be less than that in adults and risk factors, prognosis and complications are virtually unknown. Herein, we report a pediatric case developing epileptic encephalopathy following HHV-6 encephalitis after a second cord blood transplantation (CBT). A 7-year-old boy with relapsed B-precursor acute lymphoblastic leukemia in second remission underwent CBT. However, he received a second CBT due to graft failure. On day 25 after the second CBT, he developed short-term memory defects and seizures. He was diagnosed with HHV-6 encephalitis because HHV-6 DNA was detected in his blood and cerebrospinal fluid and abnormal hippocampal signals were seen on cranial magnetic resonance imaging (MRI). After treatment with foscarnet, HHV-6 DNA levels and MRI findings improved; however, he developed epileptic encephalopathy five months after the onset of encephalitis. There are very few reports on pediatric epileptic encephalopathy associated with HHV-6 encephalitis after HSCT. Detailed studies are needed to analyze risk factors, prognosis, and complications.

Pluripotent cell models of fanconi anemia identify the early pathological defect in human hemoangiogenic progenitors

Fanconi anemia (FA) is a disorder of genomic instability characterized by progressive bone marrow failure (BMF), developmental abnormalities, and an increased susceptibility to cancer. Although various consequences in hematopoietic stem/progenitor cells have been attributed to FA-BMF, the quest to identify the initial pathological event is still ongoing. To address this issue, we established induced pluripotent stem cells (iPSCs) from fibroblasts of six patients with FA and FANCA mutations. An improved reprogramming method yielded iPSC-like colonies from all patients, and iPSC clones were propagated from two patients. Quantitative evaluation of the differentiation ability demonstrated that the differentiation propensity toward the hematopoietic and endothelial lineages is already defective in early hemoangiogenic progenitors. The expression levels of critical transcription factors were significantly downregulated in these progenitors. These data indicate that the hematopoietic consequences in FA patients originate from the early hematopoietic stage and highlight the potential usefulness of iPSC technology for elucidating the pathogenesis of FA-BMF.

Long-term efficacy of bevacizumab and irinotecan in recurrent pediatric glioblastoma

A 5-year-old boy with glioblastoma relapsed soon after postoperative irradiation in combination with temozolomide. Second-line chemotherapy was also ineffective; therefore, the bevacizumab and irinotecan were given after a third gross-total resection of the tumor. Treatment was interrupted for 1 month due to development of posterior reversible encephalopathy syndrome, but was re-initiated at a lower dose of bevacizumab with prolonged intervals between treatments. The patient was alive and disease free 2 years after initial diagnosis. Bevacizumab and irinotecan are a promising regimen for pediatric cases of recurrent glioblastoma after gross-total resection, although the optimal treatment schedule must be determined on a patient-by-patient basis.

First-line treatment for severe aplastic anemia in children: bone marrow transplantation from a matched family donor versus immunosuppressive therapy

The current treatment approach for severe aplastic anemia in children is based on studies performed in the 1980s, and updated evidence is required. We retrospectively compared the outcomes of children with acquired severe aplastic anemia who received immunosuppressive therapy within prospective trials conducted by the Japanese Childhood Aplastic Anemia Study Group or who underwent bone marrow transplantation from an HLA-matched family donor registered in the Japanese Society for Hematopoietic Cell Transplantation Registry. Between 1992 and 2009, 599 children (younger than 17 years) with severe aplastic anemia received a bone marrow transplant from an HLA-matched family donor (n=213) or immunosuppressive therapy (n=386) as first-line treatment. While the overall survival did not differ between patients treated with immunosuppressive therapy or bone marrow transplantation [88% (95% confidence interval: 86-90) versus 92% (90-94)], failure-free survival was significantly inferior in patients receiving immunosuppressive therapy than in those undergoing bone marrow transplantation [56% (54-59) versus 87% (85-90); P<0.0001]. There was no significant improvement in outcomes over the two time periods (1992-1999 versus 2000-2009). In multivariate analysis, age <10 years was identified as a favorable factor for overall survival (P=0.007), and choice of first-line immunosuppressive therapy was the only unfavorable factor for failure-free survival (P<0.0001). These support the current algorithm for treatment decisions, which recommends bone marrow transplantation when an HLA-matched family donor is available in pediatric severe aplastic anemia.

An endobronchial inflammatory myofibroblastic tumor in a 10-yr-old child after allogeneic hematopoietic cell transplantation

IMTs belong to the group of soft tissue tumor and could occur at any anatomical site; however, the causes and growth feature remain unclear. This case report documents a 10-yr-old male suffering from slowly developing dyspnea on exertion and cough around seven months post-HCT. He was diagnosed with an endobronchial tumor based on imaging, and histology confirmed ALK-positive submucosal spindle-shaped cells with infiltrative cells, compatible with IMT. We should be aware that IMT is a potential complication of pediatric allogeneic HCT and can cause sudden airway obstruction.

Longitudinal nutritional assessment in acute lymphoblastic leukemia during treatment

BACKGROUND

A nutritional assessment of pediatric patients with cancer is important to improve their outcome. The number of longitudinal nutritional studies during treatment, however, is limited. The purpose of this study was to investigate the longitudinal changes in anthropometric measures and serum albumin level during chemotherapy in patients with acute lymphoblastic leukemia (ALL).

METHODS

We retrospectively reviewed the charts of 23 patients (19 boys, four girls) with ALL from April 2007 to March 2010. The median age at diagnosis was 4.5 years. Bodyweight, height, and serum albumin levels were measured at the start and the end point of each chemotherapy phase.

RESULTS

At diagnosis, two patients (8.7%) were underweight and five patients (21.7%) were overweight according to body mass index z-score, while five patients were underweight and three (13.0%) were overweight according to Waterlow score. The prevalence of malnourished patients did not change significantly throughout chemotherapy by either assessment. The absolute scores in either assessment were significantly reduced at the sanctuary treatment phase. Low serum albumin (<3.2 g/dL) was found in two patients at diagnosis. Mean albumin decreased significantly at the induction and the re-induction phases.

CONCLUSIONS

Given that nutritional status under a similar chemotherapeutic regimen as assessed by anthropometric measures and albumin level differed among patients, careful observation of the nutritional status and intervention may be necessary at different phases of chemotherapy.

Plasma homocysteine, methionine and S-adenosylhomocysteine levels following high-dose methotrexate treatment in pediatric patients with acute lymphoblastic leukemia or Burkitt lymphoma: association with hepatotoxicity

This study aimed to investigate: (i) changes of plasma homocysteine, methionine and S-adenosylhomocysteine levels following high-dose methotrexate (HD-MTX) treatment and (ii) the correlation of these sulfur-containing amino acids with MTX-induced hepatotoxicity. Fifteen pediatric patients with acute lymphoblastic leukemia and one patient with Burkitt lymphoma, with a total of 26 treatment courses of HD-MTX, were enrolled. Homocysteine levels increased at 24 h after HD-MTX treatment, and showed marginal decreases at 48 and 72 h. Methionine levels showed a biphasic pattern, i.e. an initial decrease at 24 h followed by increases at 48 and 72 h. S-adenosylhomocysteine exhibited a marginal decrease at 24 h. Changes of homocysteine exhibited significant correlation only with a maximum increase of alanine aminotransferase or total bilirubin from baseline. This study has demonstrated, for the first time, simultaneous changes of plasma homocysteine, methionine and S-adenosylhomocysteine following HD-MTX. The potential of homocysteine as a marker of hepatotoxicity is also presented.

Adipocytokines in childhood cancer survivors and correlation with metabolic syndrome components

BACKGROUND

Although there are several studies on the prevalence of metabolic syndrome (MetS) in childhood cancer survivors (CCS), the association between MetS components and serum adipocytokine level has not been elucidated.

METHODS

The charts of 49 patients (27 male, 22 female) who had attended the CCS clinic of the Department of Pediatrics, Kyoto University Hospital, between April 2009 and March 2010 were retrospectively reviewed. Median age was 10.7 years, and the median interval since the completion of chemotherapy was 5.1 years. The diagnosis of MetS was made based on the Japanese criteria for either children or adults.

RESULTS

Three (6.1%) of 49 patients fulfilled the criteria for MetS, and 28 (57.1%) had at least one component of MetS. High leptin level was seen in 18 patients (36.7%), and low total adiponectin level was seen in 20 (40.8%). The number of patients with high leptin was correlated with body mass index z-score (>2.0), abdominal circumference/height (≥0.5), diastolic blood pressure and fasting blood sugar. The number of patients with low total adiponectin was correlated with systolic blood pressure and triglyceride. When the patients were divided into three groups based on the number of positive MetS components (0, 1 and 2-4), leptin and adiponectin tended to be higher and lower in the third group, respectively.

CONCLUSIONS

Adipocytokines may play a role in the pathogenesis of MetS occurring in CCS. It is recommended that adipocytokines be evaluated together with MetS components at the CCS follow-up clinics.

Correlations between atrophy of the entorhinal cortex and cognitive function in patients with Alzheimer's disease and mild cognitive impairment

AIMS

In order to confirm the utility of the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) in assessing the atrophy of the entorhinal cortex, we investigated whether there were correlations between VSRAD and the scores of neuropsychological tests in the patients with Alzheimer's disease (AD) and mild cognitive impairment.

METHODS

Thirty patients, including 18 AD and 12 mild cognitive impairment patients, were included in this study. VSRAD was performed to assess the atrophy of the entorhinal cortex. The patients were carefully screened with the neuropsychological tests, including Wechsler Adult Intelligence Scale-III (WAIS-III), the Wechsler Memory Scale-Revised, the Alzheimer's Disease Assessment Scale-Cognitive Part (ADAS-cog) and the revised version of Hasegawa's Dementia Scale.

RESULTS

All patients showed atrophy with different degrees in the entorhinal cortex except one case. Z-scores had significant positive correlation with ADAS-cog, and negative correlation with Information subset of WAIS-III (respectively, P = 0.0129 and P = 0.0294). The revised version of Hasegawa's Dementia Scale and the Similarities subsets of the WAIS-III had a tendency of negatively correlating with Z-scores of VSRAD (respectively, P = 0.0532 and P = 0.0635). The Delayed Visual Reproduction subset of the Wechsler Memory Scale-Revised was also found to have a weak negative correlation with Z-scores (P = 0.0609).

CONCLUSIONS

Z-scores of VSRAD were revealed to have a close relation with many neuropsychological tests, especially ADAS-cog and the Information subset of WAIS-III. The results meant that VSRAD was a useful indictor of early diagnosis of AD, closely correlating with the changes of cognitive functions and the progression of the disease.

Successful cord blood transplantation using a reduced-intensity conditioning regimen for advanced childhood-onset cerebral adrenoleukodystrophy

The CCALD, which is caused by a mutation of the ABCD1 gene that encodes a peroxisomal membrane protein, progresses to a stage where the patient is in a vegetative state and can cause death within 3-5 yr after the appearance of neurological symptoms. Although HSCT is the only means of preventing the progression of this disease, HSCT is currently recommended only for cases diagnosed in the early stages. Previous reports on HSCT in advanced CCALD have indicated that the complications of the HSCT procedure seem to outweigh its benefits with respect to survival and neurological outcome. In this case, we successfully treated advanced CCALD with CBT using a reduced-intensity conditioning regimen to reduce regimen-related toxicity and transplant-associated morbidity and mortality. Neither neurological deterioration nor deterioration of MRI abnormalities were observed during the clinical course. We report that CBT using the reduced-intensity conditioning regimen was well tolerated, stopped disease progression and contributed to a good neuropsychological outcome in this case of advanced CCALD.

Outcome of hepatoblastomas treated using the Japanese Study Group for Pediatric Liver Tumor (JPLT) protocol-2: report from the JPLT

BACKGROUND

In the recent years, surgical resection with pre- and/or postoperative chemotherapy has markedly improved the survival rate of hepatoblastoma patients. We herein report the results of patients treated with the current protocol of the Japanese Study Group for Pediatric Liver Tumor, JPLT-2.

METHODS

A total of 279 patients with malignant liver tumor were enrolled in JPLT-2. Data from 212 hepatoblastoma cases were analyzed. PRETEXT I patients were treated with primary resection followed by low doses of cisplatin-pirarubicin (tetrahydropyranyl-adriamycin). Otherwise, patients received preoperative cisplatin-pirarubicin (CITA), followed by surgery and postoperative chemotherapy. Ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC) were given as a salvage treatment. High-dose chemotherapy with hematopoietic stem cell transplantation (SCT) was reserved for patients with metastatic diseases.

RESULTS

The 5-year overall survival rate (OS) in non-metastatic cases was 100% for PRETEXT I, 87.1% for PRETEXT II, 89.7% for PRETEXT III, and 78.3% for PRETEXT IV. The 5-year OS in metastatic cases was 43.9%. The outcome in non-metastatic PRETEXT IV cases was markedly improved, while the results of metastatic tumors remained poor.

CONCLUSIONS

JPLT-2 protocol achieved satisfactory survival among children with non-metastatic hepatoblastoma. New approaches are needed for patients with metastatic diseases.

Progressive familial intrahepatic cholestasis: a single-center experience of living-donor liver transplantation during two decades in Japan

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) results in liver cirrhosis. Therefore, some PFIC patients require liver transplantation (LT). Although three types of PFIC have been identified, their etiologies include unknown mechanisms.

PATIENTS

A total of 717 recipients who underwent living-donor LT (LDLT) at <20 yr old were enrolled in this study. Among these recipients, 14 PFIC recipients comprising 11 PFIC type 1 (PFIC1) and three PFIC type 2 (PFIC2) were evaluated.

RESULTS

Three of 11 PFIC1 recipients died, while all three PFIC2 recipients survived. Eight of 11 PFIC1 recipients showed steatosis after LDLT. Among the eight steatosis-positive PFIC1 recipients, seven showed severe steatosis and seven were complicated with steatohepatitis. Nine of 11 PFIC1 recipients showed fibrosis after LDLT, and eight of the nine fibrosis-positive PFIC1 recipients showed severe fibrosis. In contrast to the PFIC1 recipients, the PFIC2 recipients did not show any steatosis or fibrosis after LDLT.

CONCLUSIONS

The clinical courses and outcomes of PFIC1 recipients after LDLT are still not sufficient owing to steatosis/fibrosis, unlike the case for PFIC2 recipients. As PFIC1 patients will require LT during the long-term progression of the disease, further strategy improvements are required for PFIC1 patients.

Progressive familial intrahepatic cholestasis: a single-center experience of living-donor liver transplantation during two decades in Japan

BACKGROUND

Progressive familial intrahepatic cholestasis (PFIC) results in liver cirrhosis. Therefore, some PFIC patients require liver transplantation (LT). Although three types of PFIC have been identified, their etiologies include unknown mechanisms.

PATIENTS

A total of 717 recipients who underwent living-donor LT (LDLT) at <20 yr old were enrolled in this study. Among these recipients, 14 PFIC recipients comprising 11 PFIC type 1 (PFIC1) and three PFIC type 2 (PFIC2) were evaluated.

RESULTS

Three of 11 PFIC1 recipients died, while all three PFIC2 recipients survived. Eight of 11 PFIC1 recipients showed steatosis after LDLT. Among the eight steatosis-positive PFIC1 recipients, seven showed severe steatosis and seven were complicated with steatohepatitis. Nine of 11 PFIC1 recipients showed fibrosis after LDLT, and eight of the nine fibrosis-positive PFIC1 recipients showed severe fibrosis. In contrast to the PFIC1 recipients, the PFIC2 recipients did not show any steatosis or fibrosis after LDLT.

CONCLUSIONS

The clinical courses and outcomes of PFIC1 recipients after LDLT are still not sufficient owing to steatosis/fibrosis, unlike the case for PFIC2 recipients. As PFIC1 patients will require LT during the long-term progression of the disease, further strategy improvements are required for PFIC1 patients.

Successful treatment of refractory donor lymphocyte infusion-induced immune-mediated pancytopenia with rituximab

A 6-year-old male with chronic granulomatous disease, who was transplanted with bone marrow and exhibited increasing mixed chimerism, subsequently received two donor lymphocyte infusions (DLI). Two weeks after the second DLI, the patient developed acute graft-versus-host disease (GVHD) and progressive pancytopenia that was associated with autoantibody production. Conventional treatment did not improve the pancytopenia. However, administration of Rituximab (RTX) (375 mg/m(2)/week for four consecutive weeks) resulted in a rapid resolution of the pancytopenia. The patient achieved full donor chimerism without GVHD symptoms. RTX can be valuable for managing immune-mediated cytopenias that arise after DLI and are refractory to conventional therapies.

Successful autologous peripheral blood stem cell transplantation with a double-conditioning regimen for recurrent hepatoblastoma after liver transplantation

A four-yr-old boy developed a solitary metastasis nine months after living-related liver transplantation for unresectable hepatoblastoma. After resection of the metastatic lesion, he received an auto-PBSCT with a double-conditioning regimen consisting of melphalan and thiotepa. Auto-PBSCT could be safely performed without any serious regimen-related toxicity or infection. However, transient cessation of tacrolimus during myelosuppression resulted in graft rejection of the liver just after hematological engraftment, but rejection was resolved by tacrolimus and methylprednisolone. The patient is alive and free from disease two yr after auto-PBSCT without any signs of graft rejection. High-dose chemotherapy using this conditioning regimen may be feasible for recurrent hepatoblastoma after liver transplantation in terms of safety and anti-tumor activity.

SBDS-deficiency results in specific hypersensitivity to Fas stimulation and accumulation of Fas at the plasma membrane

Shwachman-Diamond syndrome (SDS) is an inherited disorder characterized by reduced cellularity in the bone marrow and exocrine pancreas. Most patients have mutations in the SBDS gene, whose functions are unknown. We previously showed that cells deficient in the SBDS protein are characterized by accelerated apoptosis and Fas hypersensitivity, suggesting that the protein might play an important role in Fas-mediated apoptosis. To study the mechanism of Fas hypersensitivity, we compared shRNA-mediated SBDS-knockdown HeLa cells and SDS marrow CD34+ cells for their sensitivity to several groups of apoptosis inducers. Marked hypersensitivity was noticed in response to Fas stimulation, but not to tumor necrosis factor-alpha, DNA-damaging agents, transcription inhibition or protein synthesis inhibition. To identify the Fas signaling factors that cause hypersensitivity, we analyzed the expression of the pathway's proteins. We found that Fas accumulated at the plasma membrane in SBDS-knockdown cells with corresponding expression of Fas transcript 1, the main Fas transcript which contains both the transmembrane domain and the death domain. However, the total levels of Fas protein and mRNA were comparable to controls, and Fas internalization occurred normally. Expression of FADD, caspase-8 and -3 were not elevated and the pathway inhibitors: ERK, c-FLIP and XIAP were not decreased. These results suggest that SBDS loss results in abnormal accumulation of Fas at the plasma membrane, where it sensitizes the cells to stimulation by Fas ligand.

[Renal insufficiency after allogeneic stem cell transplantation in children]

We retrospectively evaluated the incidence of renal insufficiency (RI) and risk factors involved in RI in 27 pediatric cases that underwent their first hematopoietic stem cell transplantation (HSCT) in our hospital. Median patient age was 7 years (7 months-16 years); 19 cases demonstrated hematological malignant disease and 8 cases showed non-malignant disease, respectively. Nineteen cases were transplanted from unrelated donors. The incidence of acute and chronic RI was 51.9% and 22.2%, respectively. The intensity of the conditioning regimen, the dose of TBI, GVHD prophylaxis, and the grade of GVHD did not significantly affect the incidence of either acute or chronic RI. Patients over 13 years old were at high risk for chronic RI. Furthermore, the incidence of chronic RI was significantly higher in patients showing a serum creatinine increase during the acute phase of HSCT that was more than three times the pre-HSCT level. RI prophylaxis such as ACE inhibitors or AII receptor antagonists is needed for older children and for those demonstrating severe RI at the early stage after HSCT.

Serial granulocyte transfusions as a treatment for sepsis due to multidrug-resistant Pseudomonas aeruginosa in a neutropenic patient

The emergence of multidrug-resistant Pseudomonas aeruginosa (MRPA) has become a major clinical problem. We successfully treated MRPA sepsis in a neutropenic patient undergoing peripheral blood stem cell transplantation with serial granulocyte transfusions. Granulocyte transfusion should be considered as a treatment for severe infection in patients with neutropenia.

Maturational sequence of neuroblastoma revealed by molecular analysis on cDNA microarrays

Neuroblastoma (NB), one of the most common solid tumors among children, is histologically classified by the degree of maturation. To elucidate the mechanisms underlying its maturational sequence, we analyzed gene-expression profiles of 14 NB tumors on cDNA microarrays consisting of 23,040 genes. Computational analysis identified 78 genes whose expression levels were significantly different between differentiating NB tumors and poorly differentiated NB tumors. This group included genes associated with cell maturation and apoptosis. Among them we identified 15 that were up-regulated in Stage IV NB tumors; these included genes encoding cell adhesion molecules and cytoskeleton proteins. The set of genes we report here should contribute to a better understanding of NB tumor maturation and could lead to development of new therapeutic strategies.

Regular spliceosomal introns are invasive in Chlamydomonas reinhardtii: 15 introns in the recently relocated mitochondrial cox2 and cox3 genes

In the unicellular green alga, Chlamydomonas reinhardtii, cytochrome oxidase subunit 2 (cox2) and 3 (cox3) genes are missing from the mitochondrial genome. We isolated and sequenced a BAC clone that carries the whole cox3 gene and its corresponding cDNA. Almost the entire cox2 gene and its cDNA were also determined. Comparison of the genomic and the corresponding cDNA sequences revealed that the cox3 gene contains as many as nine spliceosomal introns and that cox2 bears six introns. Putative mitochondria targeting signals were predicted at each N terminal of the cox genes. These spliceosomal introns were typical GT-AG-type introns, which are very common not only in Chlamydomonas nuclear genes but also in diverse eukaryotic taxa. We found no particular distinguishing features in the cox introns. Comparative analysis of these genes with the various mitochondrial genes showed that 8 of the 15 introns were interrupting the conserved mature protein coding segments, while the other 7 introns were located in the N-terminal target peptide regions. Phylogenetic analysis of the evolutionary position of C. reinhardtii in Chlorophyta was carried out and the existence of the cox2 and cox3 genes in the mitochondrial genome was superimposed in the tree. This analysis clearly shows that these cox genes were relocated during the evolution of Chlorophyceae. It is apparent that long before the estimated period of relocation of these mitochondrial genes, the cytosol had lost the splicing ability for group II introns. Therefore, at least eight introns located in the mature protein coding region cannot be the direct descendant of group II introns. Here, we conclude that the presence of these introns is due to the invasion of spliceosomal introns, which occurred during the evolution of Chlorophyceae. This finding provides concrete evidence supporting the "intron-late" model, which rests largely on the mobility of spliceosomal introns.

Temporal change of hippocampal enkephalin and dynorphin mRNA following trimethyltin intoxication in rats: effect of anticonvulsant

Trimethyltin (TMT), an organic metal, has been known to induce behavioral abnormalities including seizures and aggression. We administered TMT to rats, then, behavioral changes as well as the changes of dynorphin and Met-enkephalin mRNA were observed with or without phenobarbital treatment in order to reveal the role of neuropeptides in seizure-generating mechanisms. Met-enkephalin mRNA was significantly increased at the 2nd to 6th day after TMT administration when seizure was frequently observed. Meanwhile, dynorphin mRNA was decreased significantly from the 2nd day to 16th day during aggression score remained high. Phenobarbital abolished not only seizures and aggression, but also the changes of neuropeptide expressions. These results suggest that the changes of dynorphin mRNA are more strongly associated with aggression than seizures, while Met-enkephalin changes correlate more with seizures.

Acute and repeated administration of the selective 5-HT(2A) receptor antagonist M100907 significantly alters the activity of midbrain dopamine neurons: an in vivo electrophysiological study

We examined the effect of the acute and repeated administration of M100907 (formerly MDL 100907), a selective 5-HT(2A) receptor antagonist, on spontaneously active dopamine (DA) neurons in the substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) of rats. This was accomplished using in vivo, extracellular single unit recording. The i.v. administration of M100907 (0.01-0.64 mg/kg) did not significantly alter the basal firing rate or pattern of spontaneously active SNC and VTA DA neurons. A single injection of either 0.01 or 0.03 mg/kg i.p. of M100907 did not significantly alter the number of spontaneously active DA neurons in either the SNC or VTA areas. However, 0.1 mg/kg i.p. of M100907 significantly increased the number of spontaneously active SNC and VTA DA neurons compared to vehicle-treated animals. A single injection of all doses of M100907 significantly decreased the degree of bursting in VTA DA neurons, whereas the 0.1 mg/kg dose increased the degree of bursting in SNC DA neurons. The repeated administration (one injection per day for 21 days) of 0.03 and 0.1 mg/kg i.p. of M100907 produced a significant decrease in the number of spontaneously active SNC and VTA DA neurons compared to vehicle-treated animals. The repeated administration of M100907 did not significantly alter the firing pattern of VTA DA neurons but significantly altered the firing pattern of SNC DA neurons. The results of this study indicate that M100907 administration alters the activity of midbrain DA neurons in anesthetized rats.

Evolutionary relationship between dinoflagellates bearing obligate diatom endosymbionts: insight into tertiary endosymbiosis

The marine dinoflagellates Peridinium balticum and Peridinium foliaceum are known for bearing diatom endosymbionts instead of peridinin-containing plastids. While evidence clearly indicates that their endosymbionts are closely related, the relationship between the host dinoflagellate cells is not settled. To examine the relationship of the two dinoflagellates, the DNA sequences of nuclear small-subunit rRNA genes (SSU rDNA) from Peridinium balticum, Peridinium foliaceum and one other peridinin-containing species, Peridinium bipes, were amplified, cloned and sequenced. While phylogenetic analyses under simple models of nucleotide substitution weakly support the monophyly of Peridinium balticum and Peridinium foliaceum, analyses under more sophisticated models significantly increased the statistical support for this relationship. Combining these results with the similarity between the two endosymbionts, it is concluded that (i) the two hosts have the closest sister relationship among dinoflagellates tested, (ii) the hypothesis that the diatom endosymbiosis occurred prior to the separation of the host cells is most likely to explain their evolutionary histories, and (iii) phylogenetic inferences under complex nucleotide evolution models seem to be able to compensate significant rate variation in the two SSU rDNA.

Detection of single-stranded DNA in the hydropic vestibule after the direct injection of antigen into the endolymphatic sac of guinea pigs

Immunohistochemical study for single-stranded DNA (ssDNA) with vestibule of guinea pigs was performed after the injection of keyhole limpet hemocyanin (KLH) into the right endolymphatic sac. Endolymphatic hydrops became evident by expansion of the Reissner's membrane in the cochlea of all animals 1 day after the injection of KLH. Increased ssDNA expression was detected in the sensory epithelium and transitional area, while temporal bones in the control group did not show any ssDNA immunoreactivities. ssDNA is accompanied with the apoptotic change in the vestibule. Our results suggest that apoptotic changes could be involved in the hydropic vestibule and these phenomena lead inner ear disturbance as seen in endolymphatic hydrops.

Distribution of cognates of group II introns detected in mitochondrial cox1 genes of a diatom and a haptophyte

We identified group IIA introns that contain an open reading frame (ORF) in the mitochondrial cytochrome oxidase subunit I (cox1) genes of yellow algae, a diatom Thalassiosira (Th.) nordenskioeldii CCMP 992 collected from the east coast of USA, and a haptophyte Pavlova (Pa.) lutheri CCMP 1325 collected from Finland. Cognate introns of CCMP 1325 were detected in all Pa. lutheri strains investigated, which were collected from various oceans. In contrast, the intron was absent from closely related species belonging to the same genus Pavlova. This was also the case for the group II intron detected in a diatom Th. nordenskioeldii CCMP 992. The group II intron of CCMP 992 was located at the corresponding site to the group IIA intron found in Pylaiella (synonym, Pilayella) littoralis. The deduced secondary structures of these introns, one of which is from a diatom and the other from a brown alga, were virtually identical. In contrast, the haptophyte group II intron was inserted at a novel locus, and shares no particularly high sequence homology with any intron known to date. The phylogenetic tree based on the intronic ORF domain was not congruent with that based on the cox1 exon. The most prominent property of the intronic ORF tree was that introns located at homologous sites made robust pair clades irrespective of the phylogenetic relationships of the organisms. This suggests that mitochondrial group II introns often invade intronless alleles across the species barrier with site specificity. Homology analysis of the haptophyte intronic ORF suggested that it comprises three domains: reverse transcriptase (RT), RNA maturase (Ma), and H-N-H endonuclease. However, the intronic ORF of the diatom contains the Ma domain but is apparently missing the H-N-H domain, and its RT domain is most probably partly or completely lacking in function.

Selection of brood stock candidates of barfin flounder using an ELISA system with recombinant protein of barfin flounder nervous necrosis virus

Barfin flounder nervous necrosis virus (BFNNV), the causative agent of viral nervous necrosis (VNN) of barfin flounder, is vertically transmitted from spawners to larvae. In the present study, an ELISA with a recombinant protein of BFNNV was performed for the detection of antibodies against BFNNV and applied for the selection of brood fish in order to prevent viral vertical transmissions. Brood stocks were divided into 4 groups based on ELISA antibody titers (< or = 10, 20, 40 and >40), and the BFNNV status of the brood stocks was determined by PCR. BFNNV was detected from the brood fish in the group with an antibody titer of >40 but not from those with titers < or = 10, 20 and 40. The offspring obtained from PCR-negative brood fish pairs in each group of ELISA antibody titers were subsequently reared for observation of VNN occurrence. VNN occurred in juveniles from 2 of 9 pairs of spawners with an antibody titer > or = 40, but did not occur in spawners with an antibody titer of < or = 10. Therefore, it was concluded that selection of brood fish using both the PCR test and ELISA antibody titers could help prevent vertical transmission of BFNNV in larval production of barfin flounder.

Nitric oxide synthase inhibitor suppresses the ototoxic side effect of cisplatin in guinea pigs

Cisplatin is known to cause inner ear damage (ototoxicity). The role of inducible nitric oxide synthase (iNOS) in the cochlea of guinea pigs after injections of cisplatin or a combination of cisplatin and NOS inhibitor (NG-nitro-L-arginine methyl ester, L-NAME) i.p. was examined electro-and immunohistochemically. The auditory brain stem responses (ABR) were measured prior to injection and 3 days after the injection. Three days after injection, the cochleas were examined immunohistochemically for iNOS. We found that iNOS was expressed in the cisplatin- and L-NAME/ cisplatin-treated cochlea. The threshold shift of ABR was significant in the cisplatin group, whereas it was decreased in the L-NAME/cisplatin group. iNOS catalyzed high NO levels lead to inner ear dysfunction. Our results indicate that iNOS mediates the ototoxicity of cisplatin.

Phylogenetic analysis of diatom coxI genes and implications of a fluctuating GC content on mitochondrial genetic code evolution

In order to address the relationships among diatom groups and to investigate possible changes in their mitochondrial (mt) genetic codes, we have analyzed a 1.1-kb region of the cytochrome c oxidase subunit I (coxI) gene from eight diverse diatom species. A phylogenetic analysis of these coxI sequences including representative species of the Phaeophyta, Xanthophyta, Eustigmatophyta and Haptophyta showed that the diatoms (Bacillariophyta) formed a well-supported monophyletic group. Of the eight species investigated, four have been classified together as radial centric diatoms based on morphology. However, in our coxI tree, the two radial centrics belonging to the order Thlassiosirales (Skeletonema costatum and Thalassiosira nordenskioldii) were placed as the sister group to the multipolar centric diatoms, while the other two radial centrics (Melosira ambigua and Rhizosolenia setigera) were in another clade. Also, in two species of the Tharassiosirales we found UGA codons that occur at conserved tryptophan (Trp) sites in the coxI sequences, strongly indicating that UGA codes for Trp in these diatoms. No evidence of a deviant genetic code was detected in the other analyzed diatom species. There was no apparent relationship between the nucleotide third-position GC content of mtDNA (based on the sequenced coxI region) and the presence of a deviant genetic code.

Mitochondrial genes are found on minicircle DNA molecules in the mesozoan animal Dicyema

Animal mitochondrial DNA genomes are generally single circular molecules, 14-20 kb in size, containing a number of functional RNAs and 13 protein-coding genes. Among these, the COI, COII and COIII genes encode three subunits of cytochrome c oxidase. We have isolated and characterized these three mitochondrial genes from the mesozoan Dicyema, a primitive multicellular animal. Surprisingly, the COI, COII and COIII genes are encoded on three small, separate circular DNA molecules (minicircles) of length 1700, 1599 and 1697 bp, respectively. We estimated the copy number of each minicircle at 100 to 1000 per cell, and have shown a mitochondrial localization of the minicircles by in situ hybridization. Furthermore, we could not detect a putative "maxicircle" DNA molecule containing any combination of the COI, COII and COIII genes using either PCR or genomic Southern hybridization. Thus, our results show a novel mitochondrial genome organization in the mesozoan animal Dicyema.

Directionally evolving genetic code: the UGA codon from stop to tryptophan in mitochondria

For the comprehensive analyses of deviant codes in protistan mitochondria (mt), we sequenced about a 1.1-kb region of a mitochondrial (mt) gene, the cytochrome c oxidase subunit I (coxI) in two chlorarachniophytes, the filose amoeba Euglypha rotunda, the cryptomonad Cryptomonas ovata, the prymnesiophyte (haptophyte) Diacronema vlkianum (Pavlovales), and the diatom Melosira ambigua. As a result of this analysis, we noticed that the UGA codon is assigned to tryptophan (Trp) instead of being a signal for translational termination in two chlorarachniophytes and in E. rotunda. The same type of deviant code was reported previously in animals, fungi, ciliates, kinetoplastids, Chondrus crispus (a red alga), Acanthamoeba castellanii (an amoeboid protozoon), and three of the four prymnesiophyte orders with the exception of the Pavlovales. A phylogenetic analysis based on the COXI sequences of 56 eukaryotes indicated that the organisms bearing the modified code, UGA for Trp, are not monophyletic. Based on these studies, we propose that the ancestral mitochondrion was bearing the universal genetic code and subsequently reassigned the codon to Trp independently, at least in the lineage of ciliates, kinetoplastids, rhodophytes, prymnesiophytes, and fungi. We also discuss how this codon was directionally captured by Trp tRNA.

Distinctive origins of group I introns found in the COXI genes of three gree algae

Upon surveying the cytochrome c oxidase subunit I (COXI) gene of green algae, we found group I introns in three species of algae, Chlorella vulgaris (Cv), Scenedesmus quadricauda (Sq) and Protosiphon botryoides (Pb). The comparative analysis of these nucleotide sequences and their secondary structures revealed that the introns of Cv, Sq, and Pb belong to groups IB1, ID, and IB2, respectively. Each of the three introns contained an open reading frame (ORF) that showed a similarity to the sequence of the LAGLIDADG endonuclease family. However, each of the intronic ORFs in Sq and Pb had a discontinuity in the middle of' the sequences coding for the LAGLIDADG endonuclease. Either of the two ORFs could be restored to a sequence homologous to the LAGLIDADG endonuclease by the insertion of a nucleotide in the appropriate position. In Sq, a putative pseudo-knot structure was detected in the intronic ORF This suggests the occurrence of a ribosomal frameshift in the translation of the ORF. because such pseudo-knot structures are common in viral ORFs employing a (-1) ribosomal frameshift. In the phylogenetic tree that was inferred from the amino acid sequences of algal and non-algal intronic ORFs, the three algal ORFs did not make a cluster, but were scattered throughout the tree. In addition. each of the three algal ORFs showed a close relationship to the ORFs of non-algal introns that were inserted at the corresponding site of the COX] gene, suggesting distinctive origins of the three algal introns via independent horizontal transfers.

Evaluation of the thoracodorsal artery as an alternative conduit for coronary bypass

Complete coronary revascularization using arterial grafts has been performed recently because of their improved patency rates. However, as the need to repeat coronary bypass surgery has become more frequent, it can be difficult to find adequate conduits for further bypass surgery. Therefore, we investigated the use of the left thoracodorsal artery (LTDA) as an alternative bypass conduit. The length from its origin, internal diameter, and number and location of branches were angiographically measured in 16 patients, and in situ blood flow volume and external diameter were intraoperatively measured in 8. Moreover, each specimen of the LTDA, the internal thoracic artery (ITA), and the inferior epigastric artery (IEA) were evaluated histologically. We found that the thoracodorsal artery has the same diameter as the ITA angiographically, and the same histological findings as the IEA. In conclusion, the thoracodorsal artery may be useful as a coronary arterial graft.