Genetic and phenotypic profile of 112 patients with X-linked Charcot-Marie-Tooth disease type 1.

BACKGROUND AND PURPOSE: X-linked Charcot-Marie-Tooth disease type 1 (CMTX1), caused by mutations in gap junction protein beta 1 (GJB1), is characterized by various central nervous system symptoms and gender differences of clinical severity. The aim of this study was to identify the frequency and mutation spectrum of CMTX1 patients in Japan and to demonstrate their phenotypic diversities. METHODS: Using three high-throughput sequencing systems, targeted gene panel sequencing on 1483 unrelated index patients with suspected Charcot-Marie-Tooth (CMT) disease was performed. The peripheral and central nervous system involvements of all patients with GJB1 variants were assessed retrospectively and a detailed gender comparison was conducted with the CMT examination score. RESULTS: Twenty-three novel and 36 described GJB1 variants were identified from 88 pedigrees, in which 34 female and 78 male patients were enrolled. Mean age at onset of the male patients was much younger than the females, 21.56 ± 17.63 years vs. 35.53 ± 23.72 years (P = 0.007). Male patients presented with more severe phenotypes in every examination item, but statistical differences were observed only in motor dysfunctions of the lower extremities and vibration sensation. No significant sensory difference was identified between genders, either clinically or electrophysiologically. Central nervous system dysfunctions were found in 15 patients from 12 pedigrees. Therein, six patients developed stroke-like phenotypes, with dysarthria as the leading symptom. CONCLUSIONS: A relatively lower frequency of CMTX1 (5.9%) was demonstrated and a broad mutation spectrum of GJB1 was described. Detailed clinical differences between genders and various central nervous system symptoms were also illustrated, even in the same pedigree.

Detection of oxidized low-density lipoproteins in gingival crevicular fluid from dental patients.

BACKGROUND AND OBJECTIVE: Oxidative modification of low-density lipoprotein (LDL) occurs in various diseased tissues and sites of local inflammation. For example, an increased plasma oxidized low-density lipoprotein (OxLDL) level is a well-known risk marker for cardiovascular diseases. Gingival crevicular fluid, the exudate from gingival tissues into the sulci, can be easily collected in a non-invasive manner. However, the possible presence of OxLDL in gingival crevicular fluid has not been studied. In this study, we established a procedure to measure OxLDL in human gingival crevicular fluid. MATERIAL AND METHODS: Human gingival crevicular fluid was sampled with paper points or paper strips. The gingival crevicular fluid samples from healthy gingival sulci (pocket depth < 4 mm, n = 14) were subjected to western blot and/or sandwich ELISA. The amounts of OxLDL and LDL were measured by sandwich ELISA using an anti-oxidized phosphatidylcholine monoclonal antibody and two anti-apolipoprotein B antibodies. Venous blood samples were analyzed biochemically. RESULTS: We tested two methods of gingival crevicular fluid collection, namely paper points and paper strips. Gingival crevicular fluid could be collected very safely with paper points and they showed good recovery of LDL and OxLDL throughout the analysis. Apolipoprotein B, the major protein component in LDL, was detected in gingival crevicular fluid by western blot, and OxLDL was found to be present in gingival crevicular fluid by ELISA. The OxLDL/LDL ratio in gingival crevicular fluid was 17.0 times higher than that in plasma. CONCLUSION: This is the first report to show the presence of apolipoprotein B and apolipoprotein B- oxidized phosphatidylcholine complex, which correspond to LDL and OxLDL, respectively, in gingival crevicular fluid.

Oxidized low-density lipoprotein increases interleukin-8 production in human gingival epithelial cell line Ca9-22.

BACKGROUND AND OBJECTIVE: Recent epidemiological studies have shown a correlation between periodontitis and hyperlipidemia. We have found high levels of oxidized low-density lipoprotein (OxLDL) in the gingival crevicular fluid of dental patients. In the present study, we tried to examine the possible role of OxLDL in periodontal inflammation in vitro. MATERIAL AND METHODS: Cells of the human gingival epithelial cell line Ca9-22 were cultured in media containing OxLDL, and the amounts of interleukin-8 (IL-8) and prostaglandin E(2) (PGE(2)) produced were measured using ELISAs. RESULTS: Production of IL-8 by Ca9-22 cells was significantly increased when the cells were treated with OxLDL, but not with native LDL or acetylated LDL. Production of PGE(2) by Ca9-22 cells was enhanced by co-incubation with OxLDL and interleukin-1 beta (IL-1 beta). Scavenger receptor inhibitors, fucoidan and dextran sulfate, inhibited the OxLDL-induced IL-8 and PGE(2) production in the presence of IL-1 beta. The p(38) MAPK inhibitors SB203580 and SB202190 and the ERK inhibitor PD98059 inhibited the OxLDL-induced IL-8 production. Among oxidized lipids and chemically modified LDL, 7-ketocholesterol enhanced IL-8 production. CONCLUSION: This is the first report to show that OxLDL enhances IL-8 production in epithelial cells.

A novel missense mutation (p.P52R) in amelogenin gene causing X-linked amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is a hereditary disease with abnormal dental enamel formation. Here we report a Japanese family with X-linked AI transmitted over at least four generations. Mutation analysis revealed a novel mutation (p.P52R) in exon 5 of the amelogenin gene. The mutation was detected as heterozygous in affected females and as hemizygous in their affected father. The affected sisters exhibited vertical ridges on the enamel surfaces, whereas the affected father had thin, smooth, yellowish enamel with distinct widening of inter-dental spaces. To study the pathological cause underlying the disease in this family, we synthesized the mutant amelogenin p.P52R protein and evaluated it in vitro. Furthermore, we studied differences in the chemical composition between normal and affected teeth by x-ray diffraction analysis and x-ray fluorescence analysis. We believe that these results will greatly aid our understanding of the pathogenesis of X-linked AI.

Overexpression of retinoic acid receptor alpha suppresses myeloid cell differentiation at the promyelocyte stage.

Retinoic acid receptor (RAR) alpha is required to heterodimerize with retinoid X receptor (RXRs) in order to regulate myeloid differentiation. If so, it is expected that overexpression of normal RAR alpha may perturb the RAR alpha/RXR heterodimer formation and also the differentiation of myeloid cells. We have described here the morphology and the RA response of human RAR alpha cDNA transduced murine bone marrow cells using a retroviral vector. Most of RAR alpha transduced cells displayed promyelocyte like morphology and their proportion of c-kit expressing population was increased remarkably compared with the control (Neor gene transduced cells). Furthermore, this morphology was observed even after these cells were brought into the semisolid culture containing IL-3 alone. Interestingly, immature RAR alpha transduced cells differentiated into mature granulocytes under the condition of the high concentration of RA(10(-6) M). We did not observe any effect of RAR alpha on monocytes. These results indicate that overexpression of normal RAR alpha is sufficient for inducing maturation arrest of myeloid cell lineage that is similar to the phenotype found in the acute promyelocytic leukemia bearing PML-RAR alpha translocation.

Detection of a novel splice-site mutation that results in skipping exon 3 of the WASP gene in a patient with Wiskott-Aldrich syndrome.

Wiskott-Aldrich syndrome (WAS) is one of the primary immunodeficiency diseases, that is inherited as an X-linked recessive trait. Since the responsible gene, the WASP gene, has been identified, various mutations for patients with WAS have been reported. We found a novel splice-site mutation in a patient with clinically diagnosed WAS. The mutation was a replacement of ag by aa in an acceptor site of intron 2 of the WASP gene. Sequencing studies of the WASP cDNA of the patient revealed that exon 3 of the WASP gene was abnormally missing due to a splicing defect.

The effect of benzodiazepines on the binding of [3H]SCH 23390 in vivo.

The effect of flunitrazepam upon the binding of [3H]SCH 23390 in vivo was investigated. Acute treatment with flunitrazepam decreased the binding of [3H]SCH 23390 in the striatum in a dose-dependent manner. The time course of radioactivity in the striatum, cerebral cortex and cerebellum in controls and flunitrazepam (1 mg/kg)-treated mice was measured after intravenous injection of [3H]SCH 23390. The binding kinetics were calculated, using the cerebellum as a reference region for the estimation of the amount of free ligand in the brain. Flunitrazepam significantly decreased the input rate constant to the receptor compartment and the dissociation rate constant in vivo. An in vivo displacement study, using carrier SCH 23390, also showed significant reduction in the dissociation rate constant of [3H]SCH 23390 in vivo. The drug Ro 15-1788 reversed the effect of flunitrazepam, suggesting that this reduction in binding of [3H]SCH 23390 was mediated by benzodiazepine receptors. To evaluate the relationship between the reduction in binding of [3H]SCH 23390 in vivo and in vivo occupancy of benzodiazepine receptors, in vivo occupancy of benzodiazepine receptors was measured using [3H]Ro 15-1788. A non-linear relationship was found between the reduction in dopamine D1 receptor binding in vivo and the occupancy of benzodiazepine receptors in vivo, indicating that benzodiazepines exerted the maximum change in dopamine receptor binding at a low fractional occupancy of receptors.

The activation of T cells with Staphylococcus aureus Cowan 1 (SAC).

We reported our findings on the activation and functional capacity of human T cells stimulated by Staphylococcus aureus Cowan 1 (SAC). Serial determinations of surface markers on T cells stimulated by SAC showed that OKT4+ T cells remained relatively constant with the decrease of OKT8+ T cells and that Tac antigen was predominantly expressed on OKT4+ T cells. When the mixture of OKT4+-depleted T cells and OKT8+-depleted PBL was stimulated with SAC or PWM, PWM-stimulated OKT4+-depleted T cells suppressed immunoglobulin production by OKT8+-depleted PBL in a dose-dependent fashion, but SAC-stimulated OKT4+-depleted T cells did not show suppressive activity.

Elevation of serum IgE level and peripheral eosinophil count during T lymphocyte-directed gene therapy for ADA deficiency: implication of Tc2-like cells after gene transduction procedure.

We have successfully carried out T-cell-directed gene therapy for a boy with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA SCID) and unexpectedly found an elevation of serum IgE level and peripheral eosinophil count during the course. More than 90% of transduced cells cultured for 7-11 days before infusion into the patient were positive for CD8 and expressed Th2-type cytokine genes such as IL-4, IL-5 and IL-13. Furthermore, CD4(+) T-depleted PBMC (peripheral blood mononuclear cells) from the patient synthesized IgE in vitro by stimulation with IL-4. Collectively, these results suggested that Tc2-like cells in the transduced cells have distinct immunological functions to help IgE synthesis and activate eosinophils.

Association between the MB system and asthma in the Japanese.

Twenty-three unrelated Japanese patients with asthma who showed a high total serum IgE level, a strong skin test response to Dermatophagoides farinae, and a high score on a radioallergosorbent test (RAST) using Dermatophagoides farinae were typed for HLA-A locus, -B locus, and -D region antigens. No significant difference in the frequencies of HLA-A, -B, and -DR antigens were observed between the asthma patients and the healthy controls. A significant difference in the frequency of MB3', however, was found between the asthma patients and the healthy controls (corrected p = 0.04, relative risk = 18.5).

Adenosine deaminase deficiency as the first target disorder in gene therapy.

In the past decade, the advent of gene therapy has been acclaimed as a revolutionary medical intervention, embraced with great enthusiasm. However, recent disappointing results of the considerable clinical trials have also clearly demonstrated that such an initial expectation was an overestimation of gene therapy. There are only a few successful cases despite the 3000 patients who have been treated with various forms of gene therapy. Gene therapy for severe combined immunodeficiency (SCID) caused by adenosine deaminase (ADA) deficiency is one of the few such cases where results have been promising. In particular, peripheral T-lymphocytes-directed gene therapy provides further immunological improvements for patients with ADA-SCID receiving the PEG-ADA treatment whereas gene therapy targeting haematopoietic stem cell has so far proved insufficient for clinical benefits. This report will review crucial problems elucidated in the past five clinical trials for ADA-SCID and gives an outline of the next generation of stem cell gene therapy in Japan.

Visible integration of the adenosine deaminase (ADA) gene into the recipient genome after gene therapy.

Gene therapy for patients with adenosine deaminase (ADA) deficiency has become practical in the 1990s, and the exogenous gene has been reported to survive for several years in the recipient genome. To evaluate the integration efficiency of the ADA gene (ADA) into peripheral blood lymphocytes (PBL) of a patient with ADA deficiency who is receiving gene therapy, we performed two-color interphase fluorescence in situ hybridization (FISH) analysis by using digoxigenin-labeled ADA-cDNA and the biotin-labeled lambda-genomic ADA clone as probes. After each of 9 sequential series of gene therapy, interphase nuclei of 100 mononuclear cells from the patient were analyzed, and those of a LASN-producing cell line were used as a control. FISH signals were detected with rhodamine and FITC for the cDNA and the genomic DNA, respectively. The number of PBL giving a transgene signal grew after the sequential gene therapies, and the proportion of signal-positive cells reached about 10%. Our results indicate that the two-color FISH system can be used as a potential aid to monitor the efficiency of the ADA gene therapy.

High irradiation sensitivity of epstein-barr-virus (ebv) in lymphoblastoid-cells from patients with ataxia-telangiectasia and ebv genome-positive burkitts-lymphoma.

Epstein-Barr virus (EBV)-immortalized lymphoblastoid cell lines derived from the peripheral blood of patients with ataxia telangiectasia (AT) and EBV genome-positive Burkitt's lymphoma (BL) were tested for expression of EBV-related lytic antigens by means of irradiation. We used 1 Gy in each experiment, according to the results of the P3HR-1 (derived from African BL) cell line. Significantly higher expression of early antigens (EA) and viral capsid antigen (VCA) was demonstrated in lymphoblastoid cell lines derived from both patients with AT and those with EBV genome-positive BL, as compared to those derived from healthy individuals. These results suggested that defective regulating mechanisms on B lymphocytes, responsible for EBV infection, may underlie for the pathogenesis of development of lymphoproliferative diseases both in patients with AT and EBV genome-positive BL.

Epstein-barr-virus hypersensitivity of lymphocytes from patients with ataxia-telangiectasia.

Ataxia telangiectasia (AT), an autosomal recessive disorder with a high incidence of lymphoreticular malignancies including Epstein-Barr virus (EBV)-induced lymphoproliferative disorders (LPD), was investigated to assess the susceptibility to EBV infection and oncogenesis. When the patients' lymphocytes were infected with B95-8 EBV, there was a tendency toward an enhanced growth in semisolid agar, as compared with the healthy donor counterparts. Among the preparations tested, from 14 patients, 2 cell lines showed extremely high colony forming efficiency. The lymphocytes from patients with AT did not contain a large number of EBV target cells, as determined by the maximum frequency of EBV-determined nuclear antigen (EBNA) induction prior to cellular DNA synthesis. Fourteen different lymphoblastoid cell lines derived from the 14 patients with AT were then examined for their EBV inducibility and superinfectibility. By treatment with 12-O-tetradecanoyl-phorbol-13-acetate TPA) and culturing at a lower temperature of 33-degrees-C, early antigen (EA) induction occurred approximately 6-fold and 5-fold higher, respectively, as compared with the lymphoblastoid cell lines derived from healthy controls. Viral capsid antigen (VCA) was also induced significantly by TPA or culturing at lower temperature in the lines from patients with AT, but only slightly in the control counterparts. When the lymphoblastoid cells from patients with AT were exposed to P3HR-1 EBV, EA and VCA syntheses were approximately 6- and 12-fold higher, respectively, than those in the cells derived from the healthy controls. This evidence suggested B lymphocytes of patients with AT were highly susceptible to EBV infection and possibly linked to the development of EBV-induced LPD.

Autosomal-dominant hypoplastic form of amelogenesis imperfecta caused by an enamelin gene mutation at the exon-intron boundary.

Amelogenesis imperfecta (AI) is currently classified into 14 distinct subtypes based on various phenotypic criteria; however, the gene responsible for each phenotype has not been defined. We performed molecular genetic studies on a Japanese family with a possible autosomal-dominant form of AI. Previous studies have mapped an autosomal-dominant human AI locus to chromosome 4q11-q21, where two candidate genes, ameloblastin and enamelin, are located. We studied AI patients in this family, focusing on these genes, and found a mutation in the enamelin gene. The mutation detected was a heterozygous, single-G deletion within a series of 7 G residues at the exon 9-intron 9 boundary of the enamelin gene. The mutation was detected only in AI patients in the family and was not detected in other unaffected family members or control individuals. The male proband and his brother showed hypoplastic enamel in both their deciduous and permanent teeth, and their father showed local hypoplastic defects in the enamel of his permanent teeth. The clinical phenotype of these patients is similar to that of the first report of AI caused by an enamelin gene mutation. Thus, heterogeneous mutations in the enamelin gene are responsible for an autosomal-dominant hypoplastic form of AI.

A PET study of adenosine A1 receptor in anesthetized monkey brain.

We demonstrated the distribution of adenosine A1 receptors in the anesthetized monkey brain with positron emission tomography (PET) using [(11)C]KF15372 ([1-propyl-(11)C]8-dicyclopropylmethyl-1, 3-dipropylxanthine). [(11)C]KF15372 was injected intravenously. The regional standardized uptake values and the distribution volume were calculated. We also investigated the effect of carrier on the uptake and regional brain distribution of [(11)C]KF15372. The use of [(11)C]KF15372 with dynamic PET scanning could be an appropriate method to analyze the regional binding potential of adenosine A1 receptors in living brain.

A maxillary central incisor having two root canals geminated with a supernumerary tooth.

This article reports the treatment of a maxillary left central incisor geminated with a supernumerary tooth. A patient having labial swelling around the maxillary incisors was referred to this hospital for diagnosis and endodontic treatment of the maxillary left central incisor. Clinical and radiographic examinations revealed a tooth having two roots and three canals. Examination of a rubber base impression of the cleaned canals showed there was neither perforation of, nor communication with, the radicular groove in the tooth.

Good's syndrome with a block in the early stage of B cell differentiation and complicated by Campylobacter fetus sepsis.

A 63-year-old man was admitted for Campylobacter fetus sepsis and immunodeficiency syndrome with thymoma (Good's syndrome). Serological examination demonstrated hypoimmunoglobulinemia. Analysis of lymphocyte subsets in the peripheral blood and bone marrow showed marked decreases in the proportion of cells bearing B cell markers. However, there were no abnormalities of cellular immunity. This is a rare case of Good's syndrome in Japan in which the pathogenic mechanism involved a block in the early stage of B cell differentiation. Moreover, this is the first case ever reported of Campylobacter fetus sepsis associated with Good's syndrome.

Myocardial adenosine A2a receptor imaging of rabbit by PET with [11C]KF17837.

Adenosine A2a receptors are found in the endothelia, vascular smooth muscle cells and cardiac myocytes. The properties of a carbon-11 labeled A2a antagonist [11C]KF17837 ([7-methyl-11C](E)-8-(3,4-dimethoxystyryl)-1,3-dipropyl-7-methy lxa nthine) for myocardial imaging were evaluated by dynamic PET scanning of the myocardium in rabbits. Myocardial uptake of [11C]KF17837 was clearly visualized by PET. The tracer was taken up at a high level by the myocardium immediately after the injection, and the myocardial level of radioactivity gradually decreased. On the other hand, an inactive [11C]Z-isomer of [11C]KF17837 showed a very low myocardial uptake and the myocardium was not visualized with a selective A1 antagonist [11C]KF15372. By co-injection with carrier KF17837 or a xanthine type A2a antagonist 7-chlorostyrylcaffeine (CSC), the myocardial uptake of [11C]KF17837 was completely blocked. The effect of non-xanthine A2a antagonists ZM 241,385 and SCH 58,261, which have a higher affinity than CSC, was smaller than that of the CSC. The effect of weak antagonists caffeine and alloxazine or a xanthine type A1 antagonist KF15372 on the radioactivity level was small. It is concluded that PET with [11C]KF17837 can image myocardial adenosine A2a receptors.

Evaluation of the brain uptake properties of [1-11C]labeled hexanoate in anesthetized cats by means of positron emission tomography.

Positron emission tomography (PET) was performed on the cat brain to characterize [1-11C]hexanoate and other [1-11C]labeled short and medium-chain fatty acids as a tracer of fatty acid oxidative metabolism. After an intravenous injection the brain uptake of [1-11C]hexanoate reached a peak followed by rapid washout until 2 min (first phase). Subsequently the total brain uptake was again increased and reached to a peak 7-10 min after tracer injection (second phase). The blood radioactivity of unmetabolized [1-11C]hexanoate was rapidly decreased and almost eliminated within the first 2 min, whereas the blood radioactivity of [11C]CO2/HCO3- was gradually increased and reached a peak approximately 5 min after tracer injection. As the effect of circulating [11C]CO2/HCO3- was examined by a bolus intravenous injection of [11C]CO2/HCO3-, the brain uptake of [11C]CO2/HCO3- was rapidly increased right after the injection and changed parallel to the blood level of [11C]CO2/HCO3-. These results suggest that, in contrast to the previous mouse data, the time-activity curve in the cat brain following intravenous injection of [1-11C]hexanoate has a biphasic pattern, the second phase being determined by peripherally originating [11C]CO2/HCO3-, and therefore does not reflect the metabolism of 11C-labeled fatty acid in the brain.