Relation of polymorphism in the promotor region for the human osteocalcin gene to bone mineral density and occurrence of osteoporosis in postmenopausal Chinese women in Taiwan

Osteoporosis is a common disorder with a strong genetic component. Our aim was to evaluate the correlation of the HindIII osteocalcin gene polymorphism to bone mineral density (BMD) and their relationship to osteoporosis. We determined the HindIII osteocalcin gene polymorphism using polymerase chain reaction (PCR)-based restriction analysis in postmenopausal Chinese women in Taiwan. The osteocalcin gene polymorphism was detected by the restriction enzyme HindIII, where the H allele indicated the absence of the cuttable site and the h allele indicated its presence. We then related the genotypes to BMD and occurrence of osteoporosis in these women. The allelic frequencies for postmenopausal Chinese women in Taiwan were 64% for h and 36% for H in HindIII restriction fragment length polymorphisms. The prevalence of each genotype in the study population was 37.7% hh, 52.6% Hh, and 9.7% HH. The subjects with genotype hh had the greatest BMD at the lumbar spine and the femoral neck, and those with HH had the smallest BMD at the femoral neck, but these differences did not reach statistical significance. The HindIII osteocalcin genotype showed a significant effect on the prevalence of osteoporosis in the subjects at the femoral neck, that is, women with genotype HH had a 6.4 times greater risk for osteoporosis (P < 0.05), and those with genotype Hh had a 1.2 times greater risk than women with genotype hh. In conclusion, the HindIII osteocalcin gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the femoral neck.

Neuronal migration and the evolution of the human brain

A new study demonstrating a pathway for neuronal migration in humans, but not in monkeys, suggests that migration has a key role in the evolution of the brain, as well as its development.

Spermatogenesis and the regulation of Ca(2+)-calmodulin-dependent protein kinase IV localization are not dependent on calspermin

Calspermin and Ca(2+)-calmodulin-dependent protein kinase IV (CaMKIV) are two proteins encoded by the Camk4 gene. CaMKIV is found in multiple tissues, including brain, thymus, and testis, while calspermin is restricted to the testis. In the mouse testis, both proteins are expressed within elongating spermatids. We have recently shown that deletion of CaMKIV has no effect on calspermin expression but does impair spermiogenesis by disrupting the exchange of sperm basic nuclear proteins. The function of calspermin within the testis is unclear, although it has been speculated to play a role in binding and sequestering calmodulin during the development of the germ cell. To investigate the contribution of calspermin to spermatogenesis, we have used Cre/lox technology to specifically delete calspermin, while leaving kinase expression intact. We unexpectedly found that calspermin is not required for male fertility. We further demonstrate that CaMKIV expression and localization are unaffected by the absence of calspermin and that calspermin does not colocalize to the nuclear matrix with CaMKIV.

Zinc status affects p53, gadd45, and c-fos expression and caspase-3 activity in human bronchial epithelial cells

This study was designed to examine the influence of zinc depletion and supplementation on the expression of p53 gene, target genes of p53, and caspase-3 activity in normal human bronchial epithelial (NHBE) cells. A serum-free, low-zinc medium containing 0.4 micromol/l of zinc [zinc deficient (ZD)] was used to deplete cellular zinc over one passage. In addition, cells were cultured for one passage in media containing 4.0 micromol/l of zinc [zinc normal (ZN)], which represents normal culture concentrations (Clonetics); 16 micromol/l of zinc [zinc adequate (ZA)], which represents normal human plasma zinc levels; or 32 micromol/l of zinc [zinc supplemented (ZS)], which represents the high end of plasma zinc levels attainable by oral supplementation in humans. Compared with ZN cells, cellular zinc levels were 76% lower in ZD cells but 3.5-fold and 6-fold higher in ZA and ZS cells, respectively. Abundances of p53 mRNA and nuclear p53 protein were elevated in treatment groups compared with controls (ZN). For p53 mRNA abundance, the highest increase (3-fold) was observed in ZD cells. In contrast, the highest increase (17-fold) in p53 nuclear protein levels was detected in ZS cells. Moreover, gadd45 mRNA abundance was moderately elevated in ZD and ZA cells and was not altered in ZS cells compared with ZN cells. Furthermore, the only alteration in c-fos mRNA and caspase-3 activity was the twofold increase and the 25% reduction, respectively, detected in ZS compared with ZN cells. Thus p53, gadd45, and c-fos and caspase-3 activity appeared to be modulated by cellular zinc status in NHBE cells.

[A comparative study of craniofacial morphologic differences between groups with shallow and deep antegonial notch depth]

OBJECTIVE

To evaluate the correlation between craniofacial morphology and antegonial notch depth of the mandible.

METHODS

42 patients of ear ly permanent dentition from Nanchang city, 21 with shallow and 21 with deep antegonial notch were selected. Lateral cephalometric film before treatment were taken. Hard tissue angular and linear measurement were performed. The correlation between antegonial notch depth and craniofacial morphology were analysed statistically.

RESULTS

The angular measurements of SN-GoGn, S-ArGo, FH-GoMe,and ANS-Xi-Pm were significantly greater in the deep antegonial notch group. Other angles as SNB, SNP-BaN-CCGn, FH-NPg and MD-AA were significantly greater in the shallow antegonial notch group. For the linear measurements, those items as N-Me, ANS-Me,Convexity and LM-GoGn were significantly greater in the deep antegonial notch group.

CONCLUSION

The deep antegonial notch group showed steeper mandibular plane, smaller chin, greater anterior facial height and gonial angle, and has a mandible with more backward and downward growth.

Mutation analysis of type II Gaucher disease in five Taiwanese children: identification of two novel mutations

Gaucher disease (GD), one of the most prevalent lysosomal storage diseases, is caused by deficiency of lysosomal acid beta-glucosidase (GBA). It is divided into three types according to the presence and progression of neurologic symptoms. Of those, type II is relatively rare and most severe; patients usually die before the age of two years. Using polymerase chain reaction (PCR) and direct sequencing of GBA gene in five Taiwanese type II GD patients, we identified two novel mutations: G355D and three-nucleotide insertion in exon 7 of GBA. The latter resulted in an in-frame insertion of a methionine residue between Leu241 and Ser242. L444P, the second most common GD allele among non-Jewish Caucasian population, was found in all five type II GD patients (50%). Overall, 9 out of 10 GD alleles were identified in this study. Direct sequencing of all PCR products led to high detection rate of GD alleles and identification of the RecNci 1 alleles. In the future, high throughput sequencing will make it possible identifying more rare mutations in type II GD patients.

A pilot study of neonatal screening by electrospray ionization tandem mass spectrometry in Taiwan

Amino acid and acylcarnitine profiling of dry blood specimens using electrospray tandem mass spectrometry (ESI/MS/MS) has been recognized as an useful tool for screening inherited metabolic defects of newborns. In this pilot study, we introduced this technology to screen 2100 newborns to establish the normal amino acid and acylcarnitine level. Based on the upper cutoff level (average + 4*SD), twenty-nine samples studied were considered as abnormal. After follow-up samples and urine GC/MS analysis, only two were confirmed as true inborn errors. One was identified as hyperphenylalaninemia, and the other as isovaleric acidemia. The positive rate of true inborn metabolic error was 0.09% (2/2100), and the false positive rate 1.28% (29/2100) in this study. ESI/MS/MS is proven to be an adequate tool for inborn metabolic error screening.

Oxygen-induced seizures and inhibition of human glutamate decarboxylase and porcine cysteine sulfinic acid decarboxylase by oxygen and nitric oxide

The recombinant forms of the two human isozymes of glutamate decarboxylase, GAD65 and GAD67, are potently and reversibly inhibited by molecular oxygen (Ki = 0.46 and 0.29 mM, respectively). Inhibition of the vesicle-associated glutamate decarboxylase (GAD65) by molecular oxygen is likely to result in incomplete filling of synaptic vesicles with gamma-aminobutyric acid (GABA) and may be a contributing factor in the genesis of oxygen-induced seizures. Under anaerobic conditions, nitric oxide inhibits both GAD65 and GAD67 with comparable potency to molecular oxygen (Ki = 0.5 mM). Two forms of porcine cysteine sulfinic acid decarboxylase (CSADI and CSADII) are also sensitive to inhibition by molecular oxygen (Ki = 0.30 and 0.22 mM, respectively) and nitric oxide (Ki = 0.3 and 0.2 mM, respectively). Similar inhibition of glutamate decarboxylase and cysteine sulfinic acid decarboxylase by two different radical-containing compounds (O2 and NO) is consistent with the notion that these reactions proceed via radical mechanisms.

Mutation analysis of Crouzon syndrome and identification of one novel mutation in Taiwanese patients

BACKGROUND

Crouzon syndrome is an autosomal dominant disorder causing premature fusion of the cranial suture. Mutations have been reported in exon IIIa or IIIc of the fibroblast growth factor receptor 2 (FGFR2) gene.

METHODS

In the present study, nine unrelated Crouzon syndrome patients were screened for mutations in the two exons of FGFR2 by polymerase chain reaction and direct sequencing.

RESULTS

Mutations were detected in 67% (6/9) of all cases. More than half the studied Crouzon patients carried a mutation resulting in either the loss or gain of a cysteine residue. A novel mutation, Tyr281Cys substitution, was discovered at exon IIIa.

CONCLUSIONS

The mechanisms by which the same genotypes cause different phenotypes for each type of craniosynostosis syndrome in still uncertain. However, the molecular identification of the FGFR gene has made a great impact on the clinical classification of craniosynostosis syndromes; a new classification based on genotypes seems to be unavoidable.

{3,3′-[2,2′-(Ethylenedioxy)dibenzylidene]bis(S-methyl dithiocarbazate)}nickel(II)

The tetradentate N(2)S(2) Schiff base ligand 3,3'-[2,2'-(ethylenedioxy)dibenzylidene]bis(S-methyl dithiocarbazate) (H(2)L), prepared by the condensation of S-methyl dithiocarbazate with 1,4-bis(2-formylphenyl)-1,4-dioxabutane in a 1:2 molar ratio, reacts with nickel acetate to form the title neutral metal complex, [Ni(C(20)H(20)N(4)O(2)S(4))]. The X-ray structure of the complex shows a distorted square-planar geometry around the Ni atom. The monomeric units are weakly associated into dimers via a long Ni.S interaction [3.569 (1) A]. These dimeric units are then linked by C-H.S intermolecular contacts to form a polymeric chain along the a axis.

Epidermal growth factor receptor-targeted therapy with C225 and cisplatin in patients with head and neck cancer

C225, a human-mouse chimerized monoclonal antibody directed against the epidermal growth factor receptor (EGFr), has a synergistic effect with cisplatin in xenograft models. To determine the tumor EGFr saturation dose with C225 and the fate of infused C225, we conducted a Phase Ib study with C225 in combination with cisplatin in patients with recurrent squamous cell carcinoma of the head and neck. Using tumor samples, we assessed tumor EGFr saturation by antibody using immunohistochemistry studies, the EGFr tyrosine kinase assay, and detection of the EGFr/C225 complex formation by immunoblot. Potential candidates were screened for EGFr expression in their tumors, and 12 patients who had high levels of EGFr expression and tumors easily accessible for repeated biopsies (pretherapy, 24 h after first C225 infusion, 24 h before third C225 infusion) were entered at three different dose levels of C225 with a fixed dose of cisplatin. The median value of tumor EGFr saturation increased to 95% at the higher dose levels. EGFr tyrosine kinase activity was significantly reduced after C225 infusion, and EGFr/C225 complexes were also detected at higher doses of C225. The loading dose of C225 at 400 mg/m(2) with a maintenance dose at 250 mg/m(2) achieved a high percentage of saturation of EGFr in tumor tissue, and these doses were recommended for Phases II or III clinical trials. Six (67%) of nine evaluable patients achieved major responses, including two (22%) complete responses. Mild to moderate degrees of allergic reaction and folliculitis-like skin reactions were demonstrated. We conclude that infused C225 binds and significantly saturates tumor EGFr, which may render a high degree of antitumor activity, and provides a novel mechanism for targeting cancer therapy for patients who have EGFr expression in their tumors.

Down-regulation of interleukin-3/granulocyte-macrophage colony-stimulating factor receptor beta-chain in BCR-ABL(+) human leukemic cells: association with loss of cytokine-mediated Stat-5 activation and protection from apoptosis after BCR-ABL inhibition

Several signaling cascades are engaged by expression of the p210 bcr-abl tyrosine kinase, and evidence suggests that these signals drive leukemogenesis. In this report, signaling pathways were examined and compared between cells derived from leukemic patients and cells expressing a bcr-abl construct (MBA). The effects of acute inhibition of bcr-abl with STI-571 on these signals and the survival of bcr-abl-expressing cells were also evaluated. Expression of bcr-abl in interleukin-3 (IL-3)/granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent Mo7e cells (MBA) resulted in growth factor independence, constitutive activation of Stat-5 phosphorylation, engagement of mitogen-activated protein (MAP) kinase signals, and increased expression of PTP1B and bcl-x(L). STI-571 inhibited cell growth and induced apoptosis in bcr-abl-expressing cells (MBA, K562, BV-173, KBM5) but not in bcr-abl(-) tumor cells (Mo7e, KG-1, ME-180, Daudi). STI-571-mediated apoptosis correlated with the inhibition of Stat-5 and MAP kinase activation and a reduction in overexpressed bcl-x(L) but not in PTP1B. Inhibitor had no effect on IL-3/GM-CSF-dependent Mo7e cell signaling and did not prevent activation of the other Jak/Stat pathways (interferon alpha, IL-3/GM-CSF). However, neither IL-3 nor GM-CSF could reactivate Stat-5 after the STI-571-mediated inhibition of bcr-abl. Expression of the common beta-chain of the IL-3/GM-CSF receptor was down-regulated in Stat-5-activated myeloid leukemic cells, suppressing IL-3/GM-CSF signal transduction and the ability of these cytokines to provide apoptotic protection. These studies suggest that bcr-abl activates cytokine-independent mechanisms of survival while inactivating intrinsic cytokine signaling cascades, making bcr-abl(+) myeloid cells vulnerable to apoptosis after bcr-abl inactivation.

Pitfalls of PCR-based genotyping in patients with 21-hydroxylase deficiency

Mutation analysis of CYP21A2 gene was performed in seven patients with congenital adrenal hyperplasia (CAH) by combining differential long template polymerase chain reaction (PCR) amplification and amplified created restriction site (ACRS) methods. All mutations were identified, including five alleles of deletions, three alleles of splicing (IVS2-12[C/A] > G), four alleles of Ile172Asn, and two alleles of Arg356Trp. During the course of genetic analysis of CYP21A2, we found that misgenotyping of CAH by PCR-based method is possible if both alleles of a CAH patient were deletion mutations and at least one of them carried a CYP21A1P-CYP21A2 fusion gene. We also found a patient's mother was misgenotyping as IVS2-12[C/A] > G homozygous due to "allele dropout" in the PCR amplification process. We present in this article evidences of mis-genotyping by PCR-based amplification method. Due to the pitfalls observed in this study, we recommend that more methods, including microsatellite linkage analysis and direct sequencing, should be performed with direct amplification of known mutations in prenatal diagnosis of CAH to avoid misdiagnosis.

The neuronal repellent Slit inhibits leukocyte chemotaxis induced by chemotactic factors

Migration is a basic feature of many cell types in a wide range of species. Since the 1800s, cell migration has been proposed to occur in the nervous and immune systems, and distinct molecular cues for mammalian neurons and leukocytes have been identified. Here we report that Slit, a secreted protein previously known for its role of repulsion in axon guidance and neuronal migration, can also inhibit leukocyte chemotaxis induced by chemotactic factors. Slit inhibition of the chemokine-induced chemotaxis can be reconstituted by the co-expression of a chemokine receptor containing seven transmembrane domains and Roundabout (Robo), a Slit receptor containing a single transmembrane domain. Thus, there is a functional interaction between single and seven transmembrane receptors. Our results reveal the activity of a neuronal guidance cue in regulating leukocyte migration and indicate that there may be a general conservation of guidance mechanisms underlying metazoan cell migration. In addition, we have uncovered an inhibitor of leukocyte chemotaxis, and propose a new therapeutic approach to treat diseases involving leukocyte migration and chemotactic factors.

Dichloro(2,2'-diamino-4,4'-bi-1,3-thiazole-N3,N3')copper(II)

The title complex, [CuCl(2)(C(6)H(6)N(4)S(2))], has a flattened tetrahedral coordination. The Cu(II) atom is located on a twofold rotation axis and is coordinated by two N atoms from a chelating 2,2'-diamino-4,4'-bi-1,3-thiazole ligand and by two Cl atoms. Intramolecular hydrogen bonding exists between the amino groups of the 2,2'-diamino-4,4'-bi-1,3-thiazole ligand and the Cl atoms. The intermolecular separation of 3.425 (1) A between parallel bithiazole rings suggests there is a pi-pi interaction between them.

Short-range guidance of olfactory bulb axons is independent of repulsive factor slit

During development, mitral cells, the major output neurons of the olfactory bulb, project their axons caudolaterally into the telencephalon and form the lateral olfactory tract (LOT). Two types of guidance cues have been suggested for this projection. First, a long-range factor Slit, which is secreted from the septum, repels mitral cell axons into a caudolateral direction. Second, the pathway of mitral cell axons contains a subset of neurons designated as lot cells, which guide the axons through short-range interactions. It is not clear how these two guidance cues relate to each other and how they share the physiological roles. Here we examined the behavior of mitral cell axons in organotypic culture on ectopic application of Slit and inhibition of endogenous Slit signaling. The results suggested that the short-range guidance cue in the LOT pathway functions independently from Slit. Furthermore, our results showed that removal of the septum and inhibition of Slit signaling did not affect the projection of mitral cell axons. Although the septum and exogenous Slit can repel olfactory bulb axons, our results cast doubts on the physiological relevance of the septum and endogenous Slit in guiding the projection of mitral cell axons.

Osteocalcin gene Hind III polymorphism is not correlated with calcium oxalate stone disease

The formation of urinary stones is presumed to be associated with polymorphism of the osteocalcin gene. The most frequently seen polymorphism is the Hind III type located at the promoter region. This polymorphism has been used as a genetic marker in the search for a correlation between urolithiasis and normal subjects. In our study, a normal control group of 105 healthy people and 102 patients with calcium oxalate stones were examined. The polymorphism was seen following polymerase chain reaction-based restriction analysis. The results revealed no significant differences between normal individuals and stone patients (P = 0.978), and distribution of the TT homozygote in the control group (42.9%) was similar to that in the patient group (42.2%). Further categorization of the stone patients into normocalciuric and hypercalciuric groups also revealed no statistical differences from controls. We conclude that Hind III polymorphism of the osteocalcin gene is not a suitable genetic marker of urinary stone disease. Further searches for other polymorphisms on this gene correlated with stone disease are suggested.

Polypyrimidine track-binding protein binding downstream of caspase-2 alternative exon 9 represses its inclusion

We have been using the caspase-2 pre-mRNA as a model system to study the importance of alternative splicing in the regulation of programmed cell death. Inclusion or skipping of a cassette-type exon in the 3' portion of this pre-mRNA leads to the production of isoforms with antagonistic activity in apoptosis. We previously identified a negative regulatory element (In100) located in the intron downstream of alternative exon 9. The upstream portion of this element harbors a decoy 3' acceptor site that engages in nonproductive commitment complex interactions with the 5' splice site of exon 9. This in turn confers a competitive advantage to the exon-skipping splicing pattern. Further characterization of the In100 element reveals a second, functionally distinct, domain located downstream from the decoy 3' acceptor site. This downstream domain harbors several polypyrimidine track-binding protein (PTB)-binding sites. We show that PTB binding to these sites correlates with the negative effect on exon 9 inclusion. Finally, we show that both domains of the In100 element can function independently to repress exon 9 inclusion, although PTB binding in the vicinity of the decoy 3' splice site can modulate its activity. Our results thus reveal a complex composite element that regulates caspase-2 exon 9 alternative splicing through a novel mechanism.