[Mutation screening of the dystrophin gene in 14 Chinese Duchenne/Becker muscular dystrophy patients without gross deletions]

OBJECTIVE

To search for the dystrophin gene mutations of Duchenne muscular dystrophy (DMD) patients without gross deletions, in order to offer accurate genetic counseling and prenatal diagnosis for those families.

METHODS

All 79 exons of the dystrophin gene as well as its 5'-UTR and 3'-UTR of 14 Chinese DMD/Becker muscular dystrphy (BMD) patients without detectable gross deletions were screened by denaturing high performance liquid chromatography (DHPLC) and heteroduplex fragments were identified by subsequent sequencing.

RESULTS

Seven causative point mutations, including two novel ones, were detected in 7 patients. Fourteen known polymorphisms and 7 unknown intronic variations were also detected. Five mothers of the patients were obligate carriers.

CONCLUSION

DHPLC is an efficient way of identifying point mutations and the female carriers in DMD families.

[Rapid prenatal diagnosis of chromosome aneuploidies in 60 uncultured amniotic fluid samples by fluorescence in situ hybridization]

OBJECTIVE

To evaluate the feasibility of rapid prenatal diagnosis of chromosome aneuploidies by interphase fluorescence in situ hybridization (FISH) using uncultured amniotic fluid.

METHODS

Bacterial artificial chromosome (BAC) DNA probes were prepared and validated by using cultured peripheral blood. Interphase FISH for chromosomes 13, 18, 21, X and Y was performed in 60 amniotic fluid samples for the rapid prenatal diagnosis of chromosome aneuploidies, and the results were compared with the karyotypes from conventional cytogenetic analysis.

RESULTS

Of all 60 cases, 58 were concordant with their karyotypes, and 1 case of inv(9) and another case of t(2,12) were identified by karyotyping. Two cases of trisomy 21 and 1 case of trisomy 18 were detected by FISH and confirmed with conventional cytogenetics (sensitivity=100%). There were no false-positive or false-negative results.

CONCLUSION

This evaluation demonstrated that FISH employing BAC DNA probes could accurately and rapidly detect aneuploidies involving the above 5 chromosomes. However, as it does not identify structural chromosome aberrations and aneuploidies involving other chromosomes, it is not a substitute for conventional chromosome analysis, and the negative FISH result should be carefully interpreted.

Cloning, mapping and mutation analysis of human geneGJB5 encoding gap junction protein beta-5

By homologous EST searching and nested PCR a new human geneGJB5 encoding gap junction protein beta-5 was identified.GJB5 was genetically mapped to human chromosome 1p33-p35 by FISH. RT-PCR revealed that it was expressed in skin, placenta and fetal skin. DNA sequencing ofGJB5 was carried out in 142 patients with sensorineural hearing impairment and probands of 36 families with genetic diseases, including erythrokeratodermia (5 families), Charcot-Marie-Tooth disease (13), ptosis (4), and retinitis pigmentosa and deafness (14). Two missense mutations (686A-->G, H229R; 25C-->T, L9F) were detected in two sensorineural hearing impairment families. A heterologous deletion of 18 bp within intron was found in 3 families with heredity hearing impairment, and in one of the 3 families, a missense mutation (R265P) was identified also. But the deletion and missense mutation seemed not segregating with hearing impairment in the family. No abnormal mRNA or mRNA expression was detected in deletion carriers by RT-PCR analysis in skin tissue. Mutation analysis in 199 unaffected individuals revealed that two of them were carriers with the same 18 bp deletion.

Molecular analysis of hearing loss associated with enlarged vestibular aqueduct in the mainland Chinese: a unique SLC26A4 mutation spectrum

It has been shown that mutations in the SLC26A4 gene are involved in syndromic deafness characterized by congenital sensorineural hearing impairment and goitre (Pendred's syndrome), as well as in congenital isolated deafness (DFNB4), both of which are associated with enlarged vestibular aqueduct (EVA). The prevalence of SLC26A4 mutations in Pendred's syndrome is clearly established in many ethnic groups, but the data from Mainland Chinese patients with deafness and EVA remain poor. In this report, 15 patients from 13 unrelated Chinese families with deafness and EVA were analyzed for SLC26A4 using direct sequencing. A total of 15 pathogenic mutations were observed in 11 unrelated families, 4 of which were novel. One mutation, IVS7-2A>G, was most common, accounting for 22.3% (5/22) of all the mutant alleles, and H723R was infrequent. To date, a total of 23 mutations have been reported among the Chinese, 13 of which were unique. In conclusion, EVA could be a radiological marker for SLC26A4 analysis among Mainland Chinese hearing-loss patients, and the SLC26A4 mutation spectrum in the Chinese was different from other reported populations.

Non-viral ex vivo transduction of human hepatocyte cells to express factor VIII using a human ribosomal DNA-targeting vector

BACKGROUND

In gene therapy, one of the most important issues is the choice of the vectors. pHrneo is a human-derived vector previously constructed by our group, which can target a foreign gene into a human ribosomal DNA (hrDNA) locus.

METHODS AND RESULTS

In this study, we inserted an expression cassette of reconstructive hFVIII (hFVIII-BDDAK39) to pHrneo to construct a targeting vector: pHrneo-BDDAK39. Through electroporation of pHrneo-BDDAK39 into HL7702 cells (human hepatocyte), we identified the homologous recombinants using polymerase chain reaction, and tested the expression of hFVIII-BDDAK39 located at the hrDNA locus. The hFVIII-BDDAK39 was successfully targeted into the hrDNA locus of HL7702 by pHrneo-BDDAK39, and the efficiency of site-specific integration was 1.1 x 10(-5). The hFVIII-BDDAK39 at the hrDNA locus of HL7702 was found to be able to express efficiently (4.3 +/- 0.9 ng 10(-6) cells 24 h(-1)).

CONCLUSION

It has been indicated that the targeting vector pHrneo-BDDAK39 can be used in gene therapy for hemophilia A.

A father and son with mental retardation, a characteristic face, inv(12), and insertion trisomy 12p12.3-p11.2

A male patient with mental retardation (MR) and mild facial features was shown by high-resolution G-banding to have pericentric inversion of chromosome 12 with an unknown segment inserted into the long arm of the inverted chromosome [46,XY,inv(12)(pter-->p11.2::q14.1-->p11.2::?::q14.1-->qter)]. Both the inverted chromosome 12 and clinical manifestations were transmitted to his son. Karyotypes of the propositus' parents were normal. Studies with fluorescence in situ hybridization (FISH) in both the propositus and his son revealed that the extra segment was derived from 12p. Further FISH mapping and the genome-wide copy number detection by GeneChip Mapping 100K Array showed that an 11-Mb segment of 12p between two BAC clones, RP11-22H10 and RP11-977P2, was inserted at one of the reunion points in the long arm of the inv(12) chromosome. Analysis of parent-child transmissions of duplicated alleles using microsatellite markers defined the maternal origin of the chromosomal anomaly in the propositus and suggested a mechanism of its formation through a sister-chromatid rearrangement (SCR), that is, mismatched pairing and unequal crossover between sister chromatids as well as three break rearrangements including a U type rearrangement. Karyotypes of the propositus and his son were thus inv(12)(pter-->p11.22::q14.1-->p12.3::q14.1-->qter). This is the first report of "pure" proximal 12p-trisomy including p12.3-p11.22 region.

Mutation analysis of the ATM gene in two Chinese patients with ataxia telangiectasia

Ataxia telangiectasia (A-T) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectasia, immunodeficiency, elevated alpha-fetoprotein level, chromosomal instability, predisposition to cancer, and radiation sensitivity. Although a lot of mutations in the ATM gene have been described, there is still no report about ATM mutations in Chinese population. Using a molecular approach, we screened for ATM mutations in two patients from two unrelated Chinese families. 100 normal controls were analyzed to exclude possibility of polymorphism. Two novel mutations in the ATM gene were identified. The first one is a novel, homozygous, 1346G>C (Gly449Ala) missense mutation. The second one is a compound heterozygous mutation, which consists of a novel, 610G>T (Gly204Stop) nonsense mutation, combined with a previously reported, 6679C>T (Arg2227Cys) missense mutation. The transversions 1346G>C (Gly449Ala) and 610G>T (Gly204Stop) are not localized either in the conserved PI-3 kinase domain or in the other domains of the ATM protein. The phenotypic features were characterized by progressive cerebellar ataxia, ocular telangiectasia, elevated alpha-fetoprotein level, immunodeficiency (agammaglo-bulinemia and T-cell defect), and rearrangements of chromosomes 7 and 14; brain MRI showed cerebellar atrophy, brain SPECT showed cerebellar regional cerebral blood flow (rCBF) hypoperfusion. To our knowledge, this is the first report of ATM mutations in Mainland China, in which the transversions 1346G>C (Gly449Ala) and 610G>T (Gly204Stop) are two novel, disease-causing mutations.

Combined radiation and suicide gene therapy for Nasopharyngeal Carcinoma: in vitro and in vivo models

Nasopharyngeal carcinoma (NPC) cells are highly radiosensitive. Historically, the main modality for NPC has been radiotherapy. Now, to explore a novel and more effective approach to NPC therapy, a combined strategy of suicide gene and radiation was developed. The yeast CDglyTK (yCDglyTK) gene controlled by a synthetic CMV-enhanced Egr-1 promoter (CE) was constructed whose expression in NPC CNE-2 cells was detected by Western Blot. The cytotoxicity of the combined radio-gene therapy was assayed by MTT. The conversion rate of 5-FC to 5-FU in vitro and the bio-distribution of 5-FU in vivo were determined by HPLC. An animal study in which yCDglyTK-expressing CNE-2 tumors were treated with 5-FC and radiation was also conducted. The results reveal that yCDglyTK is expressed in CNE-2 cells, the CEyCDglyTK/5-FC system has a potent anti-tumor action in NPC, and the radio-sensitization of Egr-1 promoter plays a key role in the killing of CNE-2 cells and in the conversion of 5-FC to 5-FU. Moreover, the treated tumors regressed significantly, and a significant difference of tumor volumes was observed between the CEyCDglyTK+5-FC+radiation group and the other four groups (P<0.05). The results also showed that suicide gene therapy and radiation have a synergic anti-tumor effect on NPC, and the combined strategy of radio-gene therapy is of great potential as a substitute for the traditional method, radiation alone, in NPC therapies.

[Hydroxyapatite nanoparticles: a novel material of gene carrier]

Hydroxyapatite nanoparticles were prepared in low Ca/P ratio by a kind of electrodeposition-hydrothermal process. The suspension of nanoparticles was cultured with SGC-7901 cells; metabolically active cells were evaluated by MTT analysis. Cells grew well and the nanoparticles in the concentration range of 10-100 microg/ml had no adverse effect on the cell viability. The results show that the nanoparticles have excellent biocompatibility with cells. Agrose gel electrophoresis analysis demonstrated that the nanoparticles had the potential to adsorb EGFP-N1 at the pH ranging between 2 to 7. Nanoparticle-DNA complex could transfer EGFP-N1 into the SGC-7901 cells, and the confocal microscopy analysis revealed that the cells with green fluorescence showed the efficiency of nanoparticle uptake to be about 80% of the efficiency of the Lipofectmine TM 2 000 uptake. In vivo, nanoparticles and DNA-nanoparticle complex were injected into mice respectively via tail-vein, and the mice grew well in two weeks. The liver, kidney, and brain of the mice were sampled and detected with electron microscopy, and all of these exhibited biodistribution of nanoparticles. This study demonstrates that Hydroxyapatite nanoparticles could be used as gene carriers.

[Studies on PANK2 gene mutations in Chinese patients with Hallervorden-Spatz syndrome]

OBJECTIVE

To study pantothenate kinase 2 (PANK2) gene mutations in Chinese patients with Hallervorden-Spatz syndrome (HSS).

METHODS

PANK2 gene mutations were detected by PCR, DNA sequence analyses, restriction enzyme digestion and PCR-single strand conformation polymorphism in 5 patients, 3 unaffected family members and 51 unrelated healthy persons.

RESULTS

Novel compound heterozygous PANK2 gene mutations, A803G and T1172A, in exons 3 and 5, respectively, were found in one patient. At the same time, 3 types of single nucleotide polymorphisms, -38 t>a in 5'-UTR, IVS1+42 c>a and G77C in exon 1, were confirmed; among them, -38 t>a, IVS1+42 c>a, were first reported.

CONCLUSION

PANK2 gene mutations can cause HSS in Chinese patients.

A novel fusion suicide gene yeast CDglyTK plays a role in radio-gene therapy of nasopharyngeal carcinoma

To investigate a novel suicide gene for nasopharyngeal carcinoma (NPC) therapy, the yCDglyTK gene was constructed by fusing yeast cytosine deaminase (CD) and herpes simplex type 1 thymidine kinase. The expression of the yCDglyTK gene was detected by RT-PCR and Western blotting, and its bioactivity was demonstrated by an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. An animal study was carried out in which BALB/C nude mice bearing yCDglyTK gene-modified tumors were treated with prodrugs and radiation. Our results revealed that the yCDglyTK gene could be expressed in CNE-2 cells in vitro. In MTT analysis, at the transfection rate of 10%, 66% cells were killed. The synergistic effect of CD and TK showed 91% of yCDglyTK-transfected cells were killed with the treatment of 5-fluorocytosine (5-FC) alone, 60% killed with ganciclovir (GCV) alone, and 75% killed with 5-FC and GCV together. In vivo, the tumor volume in all of the four prodrugs and/or radiation-treated groups were significantly different from that in the PBS-controlled group (P<.01); also yCDglyTK+prodrug+radiation group was different from the other three groups (P<.05). Our findings suggested there was a synergistic antitumor effect when combining suicide gene therapy and radiation, and yCDglyTK has potent antitumor efficacy and may be a candidate suicide gene for cancer therapy.

A novel mutation in KCNQ2 gene causes benign familial neonatal convulsions in a Chinese family

Benign familial neonatal convulsions (BFNC) are a rare autosomal dominant inherited epilepsy syndrome. Two voltage-gated potassium channel genes, KCNQ2 on chromosome 20q13.3 and KCNQ3 on chromosome 8q24, have been identified as the genes responsible for benign familial neonatal convulsions. By linkage analysis and mutation analysis of KCNQ2 gene, we found a novel frameshift mutation of KCNQ2 gene, 1931delG, in a large Chinese family with benign familial neonatal convulsions. This mutation is located in the C-terminus of KCNQ2, in codon 644 predicting the replacement of the last 201 amino acids with a stretch of 257 amino acids showing a completely different sequence. An unusual clinical feature of this family is that the seizures of every patient did not remit until 12 to 18 months. This is the first report of KCNQ2 gene mutation in China.

The combination of suicide gene therapy and radiation enhances the killing of nasopharyngeal carcinoma xenographs

Nasopharyngeal carcinoma (NPC) is very common in Southern China and Southeast Asian countries. To explore a novel and more effective approach to NPC therapy, a combined strategy of suicide genes and radiation was designed in this study. Five suicide gene expression cassettes, yeast CD, yeast CD/UPRT, and yeast CDglyTK gene controlled by CMV, and Egr-1 and a synthetic CMV-enhanced Egr-1 promoter (CE) were constructed in an expression vector p11MS. The expression of suicide genes in NPC CNE-2 cells were detected by RT-PCR and Western blot. The cytotoxicity of suicide gene therapy and radiation were analyzed by MTT assay. An animal study in which yeast CD/UPRT-expressing CNE-2 tumors in nude mice were treated with 5-FC and radiation was also developed. Our results revealed that p11MSCEyCD/UPRT and p11MSCEyCDglyTK are superior over three other constructs in the killing of NPC cells in vitro. We combined suicide gene-expressing tumors, 5-FC treatment, and radiation in vivo and found that the tumors greatly regressed, some disappeared completely in 3 nude mice in the yCD/UPRT group, and a significant difference of tumor volumes was observed between this group and the other four groups (p < 0.05). Our results indicated that suicide gene therapy and radiation have a synergic effect on NPC therapy, and the combined strategy of radiogene therapy is of great potential as a substitute for the traditional method, radiation alone, in NPC therapies.

Three novel mutations of the spastin gene in Chinese patients with hereditary spastic paraplegia

BACKGROUND

Hereditary spastic paraplegia is a group of genetically heterogeneous neurodegenerative disorders characterized by progressive spasticity of the lower limbs. The most common form of hereditary spastic paraplegia is caused by mutations in the spastin gene (SPG4), which encodes spastin, an adenosine triphosphatase associated with various cellular activities protein.

OBJECTIVE

To investigate the Chinese patients with hereditary spastic paraplegia for mutations in SPG4.

METHODS

DNA samples from 31 unrelated patients were analyzed for mutations in SPG4 by single-strand conformation polymorphism analysis and direct sequencing. All DNA samples were screened for mutations by the polymerase chain reaction, followed by electrophoresis and silver staining. Each new variant identified was analyzed in 50 control subjects to determine whether it is a polymorphism or a mutation.

RESULTS

Three novel mutations were detected in 4 affected individuals, including 2 missense mutations (T1258A and A1293G) and 1 deletion mutation (1668-1670delCTA).

CONCLUSIONS

To our knowledge, this is the first report of SPG4 mutations in the People's Republic of China. The percentage of involved Chinese families with autosomal dominant hereditary spastic paraplegia with an SPG4 mutation is 18% (4/22), lower than the estimated 40% linked to this locus.

A novel locus for autosomal dominant nonsyndromic hearing loss identified at 5q31.1-32 in a Chinese pedigree

Hearing impairment is an extremely heterogeneous disorder. A total of 35 loci and 17 related genes for autosomal dominant nonsyndromic hearing loss have been identified. In a Chinese pedigree characterized by autosomal dominant inheritance with bilateral, postlingual, progressive, and sensorineural nonsyndromic hearing impairment, the putative disease gene locus was localized to chromosome 5q31.1-32 by a genome-wide scan. Fine mapping indicated that the disease gene was located within an 8.8-cM region between markers D5S2056 and D5S638, with a maximum two-point logarithm of differences (LOD) score of 6.89 (theta = 0) at D5S2017. By the candidate gene approach, mutation screening of the DIAPH1 and POU4F3 genes at 5q31 was performed. No mutation was found, suggesting that this is a novel deafness locus, which has been named DFNA42.

Sodium chloride modified silica nanoparticles as a non-viral vector with a high efficiency of DNA transfer into cells

Development of reliable vectors is a major challenge in gene therapy. Previous gene transfer methods using non-viral vectors, such as liposomes or nanoparticles, have resulted in relatively low levels (35 to approximately 50%) of gene expression. We have developed a silicon nanoparticle (SNAP) system, a novel non-viral vector, for DNA transfer into cells. SNAP was synthesized chemically and modified with sodium chloride or sodium iodide. Electronmicroscopy of SNAP and fluorescence microscopy of fluorescence-labeled SNAP revealed that they were generated uniformly, had diameters of 10-100 nm, and showed a better efficiency (about 70%) of DNA transfection into cells as well as protection of DNA against degradation. The microscopy also demonstrated the adhesion of SNAP with HT1080 cell surface and entry of SNAP into the cells without cytotoxicity. Intravenous and/or intra-abdominal administration of the SNAP to mice revealed the accumulation of SNAP in the cells of the brain, liver, spleen, lung, kidney, intestine, prostate and the testis without any pathological cell changes or mortality, suggesting that they passed through the blood-brain, blood-prostate, and blood-testis barriers. These findings indicate that the SNAP generated has good biological characteristics as a potential promising vector for gene transfer, gene therapy and drug delivery.

[Effects of vitamin A and iron supplementation on the improvement of iron status and immunological function in preschool children]

OBJECTIVE

In order to understand the changes in immunological function in rural preschool children with lower levels of vitamin A and iron, and the effect of vitamin A and iron supplementation on the improvement of iron status and immunological function.

METHODS

Serum vitamin A concentration and hemoglobin (Hb), serum iron (SI), transferrin saturation (TS), serum ferritin (SF) were determined in 270 rural preschool children aged 3-7 years in Beijing, and the subjects were divided into four groups based on their determinations: control, lower serum vitamin A, lower iron, and both lower iron and serum vitamin A. Forty subjects were selected from each group, and serum IgA, IgG, IgM and interleukin-2 (IL-2) were determined for them. Forty-one subjects who had lower iron and lower serum vitamin A (< 1.12 mumol/L) were divided into two groups: one of them supplemented with 30 mg iron element (ferrous sulfate 0.15 g) once a day for 8 weeks, and the other group supplemented with iron and 12,500 IU vitamin A twice a week for 8 weeks. After supplementation of vitamin A and iron, their serum vitamin A, hematological iron index and serum immunological index were determined again for the two groups.

RESULTS

Serum IgM were (1,260 +/- 310) mg/L in both lower iron and serum vitamin A groups, significantly higher than that in normal group (1,070 +/- 170) mg/L (P < 0.05). But there were no significant differences in serum levels of IgG, IgA and IL-2. After supplementation of iron and vitamin A, their serum TS increased to (26.5 +/- 8.6)%, significantly higher than that before supplementation and that supplemented with iron only (22.3 +/- 3.8)%. And, their serum IL-2 were (278.9 +/- 117.7) ng/L after supplementation, significantly higher than that before supplementation (161.6 +/- 90.3) ng/L and that in those supplemented with iron only (189.5 +/- 89.3) ng/L. There was no significant difference in other biochemical indices of iron and immunological indices.

CONCLUSIONS

Supplementation with vitamin A and iron was helpful to improve body iron nutritional status and immunological function obviously in preschool children with iron-deficiency and sub-clinical deficiency of vitamin A.

Determination of D- and L-aspartate in cell culturing medium, within cells of MPT1 cell line and in rat blood by a column-switching high-performance liquid chromatogrpahic method

HPLC fluorometric methods have been used to analyze trace amounts of D-amino acids in biological samples. In this study, we established an expedient column-switching fluorometric HPLC system that would improve the analysis of D-amino acids, in particular D-aspartate (Asp). Our system consists of the fluorogenic derivatization of amino acids with NBD-F and two chromatographic steps, one that separates individual amino acids in reverse phase mode and another that separates the chiral forms of each amino acid in normal-phase mode. The two separation steps are linked through a trapping column by an automated column-switching system. In addition, sample preparation is simplified and improved, where trichloroacetic acid is used for deproteinization, and borate buffer, pH 9.5 is employed for the fluorescent derivatization. The detection limit for D-Asp in culturing medium is 5 nM. The resulting peak heights correlated well with concentrations that ranged from 12.5 to 250 nM for both D- and L-Asp. The present method was applied to determine D- and L-Asp levels in cell culturing medium, and within cells of MPT1 cell line. The detected cellular levels of D- and L-Asp agree with those detected by our previous method. In addition, this method was used to measure D- and L-Asp levels in rat blood samples, and the results are consistent with the reported values.

[Changes of serum transferrin receptor in children with iron deficiency and its response to iron supplementation]

OBJECTIVES

To study the level of serum transferrin receptor (sTfR) in children with different stages of iron deficiency, as well as in the normal children, to observe its response to iron supplementation, and to explore the role of sTfR in surveillance of iron status and assessment of iron supplementation in population.

METHODS

By determining iron status index, 1,006 children aged 6-14 years in Fangshan District, Beijing were divided into four groups, control group, iron depletion (ID) group, iron deficiency erythropoiesis (IDE) group and iron deficiency anemia (IDA) group, and 239 of them were measured for sTfR with Quintikine enzyme immunoassay (R&D system, Minneapolis, MN) and sTfR/logserum ferratin (SF) was estimated. Iron supplementation (NaFeEDTA capsules, containing 60 mg iron element per capsule) was administered for the children with ID and IDE per capsule once weekly and for the children with IDA per capsule thrice weekly for nine weeks. Iron status index and sTfR were measured before and after iron supplementation.

RESULTS

The levels of sTfR and sTfR/log SF in children with ID, IDE and IDA were (20.03 +/- 2.33) nmol/L, (24.52 +/- 1.07) nmol/L, (33.28 +/- 6.09) nmol/L and (18.15 +/- 5.31), (20.98 +/- 8.88), (29.08 +/- 8.57), respectively, significantly higher than those in the control group [sTfR(18.74 +/- 3.06) nmol/L and sTfR/log SF(9.89 +/- 1.74)]. Statistical analysis showed that sTfR correlated to free erythrocyte protoporphyrin and hemoglobin. sTfR levels in normal children was (12.5-23.5) nmol/L. After iron supplementation, sTfR levels in children with ID was (16.37 +/- 3.10) nmol/L, significantly decreased than those before iron supplementation, but no change in sTfR was observed in children with IDE and IDA. sTfR/log SF were decreased significantly in all children with ID group(11.42 +/- 3.12), IDE (16.54 +/- 4.70) and IDA (23.59 +/- 9.93).

CONCLUSION

sTfR is a specific indicator for identifying IDE and IDA, and sTfR/log SF is a sensitive index for assessing the effects of iron supplementation.

[Effects of cactus, alove veral, momorcica charantia on reducing the blood glucose of diabetic mice]

The effects of cactus, alove veral and momorcica charantia on reducing the blood glucose level of mice were observed. The diabetic model with no symptom in mice was established by injection of streptozotocin(STZ) 80 mg/kg BW into abdominal cavity for 11 days. The diabetic mice were randomly divided into 8 groups: STZ diabetic model, diet A, diet B, cactus, alove veral, momordica charantia and glyburide groups. Cactus (60 g/kg BW), alove veral (60 g/kg BW), and momordica charantia (30 g/kg BW) were administrated orally each day to the diabetic mice for another 21 days. Serum glucose of mice fasting for 12 hours and 2 hours after meal was determined with the method of glucose-oxidase at the 21th day of the experiment. The results showed that serum glucose levels of diabetic mice were significantly higher than the normal control group (P < 0.01). After giving diet A, cactus, alove veral and momorcica charantia juice for 21 days, the serum glucose concentration of these diabetic mice were significantly lower than STZ diabetic model group (P < 0.01) but still higher than the normal control group.

Occurrence of D-Amino Acids and a pyridoxal 5'-phosphate-dependent aspartate racemase in the acidothermophilic archaeon, Thermoplasma acidophilum

Free D-amino acid content in some archaea was investigated and D-forms of several amino acids were found in them. In the acidothermophilic archaeon, Thermoplasma acidophilum, the proportion of D-aspartate (D-Asp) to total Asp was as high as 39.7%. Crude extracts of Thermoplasma acidophilum had Asp-specific racemase activity that was pyridoxal 5'-phosphate (PLP)-dependent. The relative insensitivity to a SH-modifying reagent distinguished this activity from those of the PLP-independent Asp racemases found in other hyperthermophilic archaea (Matsumoto, M., et al., J. Bacteriol. 181, 6560-6563 1999). Thus, high levels of d-Asp should be produced by a new type(s) of Asp-specific racemase in Thermoplasma acidophilum, although the function of d-Asp in this archaeon remains unknown.

Localization, Transport, and Uptake of -Aspartate in the Rat Adrenal and Pituitary Glands

Large amounts of D-aspartate (D-Asp) are present in the rat adrenal and pituitary glands. D-Asp is thought to be synthesized in the mammalian body and also accumulates in various tissues following intraperitoneal or intravenous administration. This report examines the origins of D-Asp in the adrenal and pituitary glands. We administered D-Asp to male rats intraperitoneally and immunolocalized this exogenous D-Asp in adrenal and pituitary tissue, using an anti-D-Asp antiserum which was previously developed in our laboratory. D-Asp levels in the rat adrenal gland have been shown to undergo a transient increase at 3 weeks of age and to decrease rapidly thereafter. We found that in the adrenal gland, exogenous D-Asp administered intraperitoneally was incorporated into the same region of the adrenal cortex in which endogenous D-Asp was present. By Northern and Western blot analysis and immunohistochemistry of glutamate (Glu) transporter, we also found that expression of the Glu transporter (GLAST), which has an affinity for D-Asp, transiently increased at 3 weeks of age and that localization patterns of the Glu transporter within the tissue were almost coincident with those of endogenous D-Asp. These observations suggest that D-Asp in the adrenal cortex of 3-week-old male rats is primarily acquired by uptake from the vascular system. We have previously shown that D-Asp is specifically localized in prolactin (PRL)-containing cells in the anterior lobe of the adult rat pituitary gland. Here we report that in the pituitary gland, exogenous D-Asp accumulated in endothelial cells, but not in PRL-containing cells. Northern and Western blot analysis and immunohistochemistry of Glu transporter revealed that developmental changes in the Glu transporter (GLAST) expression did not correlate with tissue levels of D-Asp and that the Glu transporter was not expressed in PRL-containing cells. These observations suggest that, in contrast to the adrenal gland, most of the D-Asp in the pituitary gland of adult male rats originates inside the gland itself.