Effects of IL-10 and glucose on expression of OPG and RANKL in human periodontal ligament fibroblasts

The effects of interleukin-10 (IL-10) and glucose on mRNA and protein expression of osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor-κB ligand (RANKL), were investigated in human periodontal ligament fibroblasts (HPDLFs). Primary HPDLFs were treated with different concentrations of IL-10 (0, 1, 10, 25, 50, and 100 ng/mL) or glucose (0, 5.5, 10, 20, 30, and 40 mmol/L). Changes in mRNA and protein expression were examined using the reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. After IL-10 treatment, mRNA and protein levels of OPG were increased, while mRNA and protein levels of RANKL were decreased (P<0.05), both in a concentration-dependent manner. Glucose stimulation had the opposite concentration-dependent effect to that of IL-10 on OPG and RANKL expression. IL-10 upregulated OPG expression and downregulated RANKL expression, whereas high glucose upregulated RANKL and downregulated OPG in HDPLFs. Abnormal levels of IL-10 and glucose may contribute to the pathogenesis of periodontal disease.

Bmi1 regulates auditory hair cell survival by maintaining redox balance

Reactive oxygen species (ROS) accumulation are involved in noise- and ototoxic drug-induced hair cell loss, which is the major cause of hearing loss. Bmi1 is a member of the Polycomb protein family and has been reported to regulate mitochondrial function and ROS level in thymocytes and neurons. In this study, we reported the expression of Bmi1 in mouse cochlea and investigated the role of Bmi1 in hair cell survival. Bmi1 expressed in hair cells and supporting cells in mouse cochlea. Bmi1^−/− mice displayed severe hearing loss and patched outer hair cell loss from postnatal day 22. Ototoxic drug-induced hair cells loss dramatically increased in Bmi1^−/− mice compared with that in wild-type controls both in vivo and in vitro, indicating Bmi1^−/− hair cells were significantly more sensitive to ototoxic drug-induced damage. Cleaved caspase-3 and TUNEL staining demonstrated that apoptosis was involved in the increased hair cell loss of Bmi1^−/− mice. Aminophenyl fluorescein and MitoSOX Red staining showed the level of free radicals and mitochondrial ROS increased in Bmi1^−/− hair cells due to the aggravated disequilibrium of antioxidant–prooxidant balance. Furthermore, the antioxidant N-acetylcysteine rescued Bmi1^−/− hair cells from neomycin injury both in vitro and in vivo, suggesting that ROS accumulation was mainly responsible for the increased aminoglycosides sensitivity in Bmi1^−/− hair cells. Our findings demonstrate that Bmi1 has an important role in hair cell survival by controlling redox balance and ROS level, thus suggesting that Bmi1 may work as a new therapeutic target for the prevention of hair cell death.

Deficiency of osteoblastic Arl6ip5 impaired osteoblast differentiation and enhanced osteoclastogenesis via disturbance of ER calcium homeostasis and induction of ER stress-mediated apoptosis

ADP-ribosylation-like factor 6 interacting protein 5 (Arl6ip5), which belongs to the prenylated rab-acceptor-family, has an important role in exocytic protein trafficking, glutathione metabolism and involves in cancer progression. However, its expression pattern and functional role in bone are unknown. Here we demonstrate that Arl6ip5 knock-out mice (Arl6ip5 (Δ2/Δ2)) show marked decrease of bone mineral density, trabecular bone volume and trabecular thickness. Histomorphometric studies reveal that bone formation parameters are decreased but bone resorption parameters and mRNA level of osteoclast-specific markers are increased in Arl6ip5(Δ2/Δ2) mice. In osteoblast, we demonstrate that Arl6ip5 abundantly expresses in osteoblastic cells and is regulated by bone metabolism-related hormones and growth factors. In vitro analysis reveals that osteoblast proliferation and differentiation are impaired in Arl6ip5 knocked-down and deficient primary osteoblast. Arl6ip5 is also found to function as an ER calcium regulator and control calmodulin signaling for osteoblast proliferation. Moreover, Arl6ip5 insufficiency in osteoblast induces ER stress and enhances ER stress-mediated apoptosis. CCAAT/enhancer-binding protein homologous protein (Chop) is involved in the regulation of apoptosis and differentiation in Arl6ip5 knocked-down osteoblasts. For osteoclastogenesis, Arl6ip5 insufficiency in osteoclast precursors has no effect on osteoclast formation. However, knocked-down osteoblastic Arl6ip5 induces receptor activator of nuclear factor-κB ligand (RANKL) expression and enhances osteoclastogenesis. In addition, ER stress and Chop are involved in the RANKL expression in Arl6ip5 knocked-down osteoblasts. In conclusion, we demonstrate that Arl6ip5 is a novel regulator of bone formation in osteoblasts.

The development and application of a blocking ELISA kit for the diagnosis of infectious coryza

A blocking enzyme-linked immunosorbent assay (B-ELISA) kit for the diagnosis of infectious coryza was developed in this study. The kit was based on a recently described blocking ELISA that uses monoclonal antibodies to achieve specificity for antibodies to either Haemophilus paragallinarum serovar A or serovar C. The results showed that the B-ELISA kit detected 96 and 90%, respectively, of chickens vaccinated or challenged with H. paragallinarum serovar A. When used on chickens vaccinated or challenged with H. paragallinarum serovar C, the kit detected 77 and 40%, respectively, as positive. The majority of sera from vaccinated chickens were still positive on the serovars A and C ELISAs 4 months after vaccination. Based on pen trial data, the serovar A B-ELISA kit had a sensitivity of 95% and a specificity of 100%. The serovar C B-ELISA kit had a sensitivity of 73% and a specificity of 100%. A range of field sera was examined with the kit, generating results that correlated with the known vaccination/disease history of the flocks examined. As freeze drying the monoclonal antibodies and the conjugate had some effect on optimal working concentration, the kit used liquid solutions of these two reagents. The kit could be stored for 7 days at 37 degrees C, 10 months at 4 degrees C and more than 1 yearat -20 degrees C. Our results suggest that the kit would be a useful aid in the diagnosis of infectious coryza in China and other countries where H. paragallinarum serovars A and C are the predominant or sole serovars.

A comparison of a blocking ELISA and a haemagglutination inhibition assay for the detection of antibodies to Avibacterium (Haemophilus) paragallinarum in sera from artificially infected chickens

The ability of blocking ELISAs and haemagglutination-inhibition (HI) tests to detect antibodies in sera from chickens challenged with either Avibacterium (Haemophilus) paragallinarum isolate Hp8 (serovar A) or H668 (serovar C) was compared. Serum samples were examined weekly over the 9 weeks following infection. The results showed that the positive rate of serovar A specific antibody in the B-ELISA remained at 100% from the second week to the ninth week. In chickens given the serovar C challenge, the highest positive rate of serovar C specific antibody in the B-ELISA appeared at the seventh week (60% positive) and was then followed by a rapid decrease. The B-ELISA gave significantly more positives at weeks 2, 3, 7, 8 and 9 post-infection for serovar A and at week 7 post-infection for serovar C. In qualitative terms, for both serovar A and serovar C infections, the HI tests gave a lower percentage of positive sera at all time points except at 9 weeks post-infection with serovar C. The highest positive rate for serovar A HI antibodies was 70% of sera at the fourth and fifth weeks post-infection. The highest rate of serovar C HI antibodies was 20% at the fifth and sixth weeks post-infection. The results have provided further evidence of the suitability of the serovar A and C B-ELISAs for the diagnosis of infectious coryza.

Long-term prevention of diabetes and marked suppression of insulin autoantibodies and insulitis in mice lacking native insulin B9-23 sequence

We analyzed double native insulin gene knockout NOD mice with a mutated (B16:alanine) proinsulin transgene at multiple ages for the development of insulin autoantibodies, insulitis, and diabetes. In contrast to mice with at least one copy of a native insulin gene that expressed insulin antibodies, only 2 out of 21 (10%) double native insulin gene knockout mice with a mutated insulin transgene developed insulin autoantibodies. Of 21 double insulin knockout mice sacrificed between 10 to 48 weeks of age, only 5 showed minimal insulitis versus 100% of wild-type NOD and more than 90% of insulin 1 knockout mice. Consistent with robust suppression of insulin autoantibodies and insulitis, no double insulin knockout mice developed diabetes. In that the B9-23 peptide with B16A is an altered peptide ligand inducing Th2 responses, we analyzed transfer of splenocytes into NOD.SCID mice. There was no evidence for regulatory T cells able to inhibit transfer of diabetes by diabetogenic NOD splenocytes. Insulin peptide B9-23 is likely a crucial target for initiation of islet autoimmunity and further mutation of the sequence will be tested to attempt to eliminate all anti-islet autoimmunity.

A new model of insulin-deficient diabetes: male NOD mice with a single copy of Ins1 and no Ins2

AIMS/HYPOTHESIS

We describe a novel model of insulin-deficient diabetes with a single copy of the gene encoding insulin 1 (Ins1) and no gene encoding insulin 2 (Ins2).

MATERIALS AND METHODS

We constructed five lines of mice: mice with two copies of Ins1 (NOD( Ins1+/+,Ins2-/-)), mice with a single copy of Ins1 (NOD( Ins1+/-,Ins2-/-)), mice with two copies of Ins2 (NOD( Ins1-/-,Ins2+/+)), mice with a single copy of Ins2 (NOD( Ins1-/-,Ins2+/-)) and NOD( Ins1+/-,Ins2-/-) mice with a transgene encoding B16:Ala proinsulin.

RESULTS

By 10 weeks of age, all male NOD( Ins1+/-,Ins2-/-) mice were diabetic, whereas all female NOD( Ins1+/-,Ins2-/-) were not diabetic (p < 0.0001). In contrast, neither male nor female NOD( Ins1-/-,Ins2+/-) with a single copy of Ins2 (rather than single copy of Ins1) developed early diabetes and no mice with two copies of either gene developed early diabetes. Islets of the diabetic male NOD( Ins1+/-,Ins2-/-) at this early age had no lymphocyte infiltration. Instead there was heterogeneous (between islet cells) weak staining for insulin. Although only male NOD( Ins1+/-,Ins2-/-) mice developed diabetes, both male and female NOD( Ins1+/-,Ins2-/-) mice had markedly decreased insulin content. In NOD( Ins1+/+,Ins2-/-), there was also a significant decrease in insulin content, whereas NOD( Ins1-/-,Ins2+/+) mice, and even NOD( Ins1-/-,Ins2+/-) mice, were normal. Male NOD( Ins1+/-,Ins2-/-) mice were completely rescued from diabetes by introduction of a transgene encoding proinsulin. On i.p. insulin tolerance testing, male mice had insulin resistance compared with female mice.

CONCLUSIONS/INTERPRETATION

These results suggest that Ins1 is a 'defective gene' relative to Ins2, and that the mouse lines created provide a novel model of sex-dimorphic insulin-deficient diabetes.

Initial results of screening of nondiabetic organ donors for expression of islet autoantibodies

CONTEXT

Type 1A diabetes is characterized by a long prodromal phase during which autoantibodies to islet antigens are present. Nevertheless, we lack data on the pancreatic pathology of subjects who are positive for islet autoantibodies (to islet autoantigens GAD65, insulin, and ICA512).

OBJECTIVE

In this manuscript, we describe a novel strategy in obtaining pancreata and pancreatic lymph nodes from islet autoantibody-positive organ donors that involves careful coordination among the laboratory and the organ donor provider organization.

DESIGN

We developed a rapid screening protocol for islet autoantibodies measurement of organ donors to allow identification of positive subjects before organ harvesting. In this way we were able to obtain pancreata and pancreatic lymph nodes from subjects with and without islet autoimmunity.

SETTING

The organ donors used in this study were obtained from the general community.

SUBJECTS

The population studied consisted of 112 organ donors (age range 1 month to 86 yr, mean age 39 yr).

MAIN OUTCOME MEASURE

The main outcome measure of this study consisted of evaluating the pancreatic histology and identify T cells autoreactive for islet antigens in the pancreatic lymph nodes.

RESULTS

To date we have identified three positive subjects and obtained the pancreas for histological evaluation from one of the autoantibody-positive donors who expressed ICA512 autoantibodies. Although this subject did not exhibit insulitis, lymphocytes derived from pancreatic lymph nodes reacted to the islet antigen phogrin.

CONCLUSION

In summary, these results indicate that it is possible to screen organ donors in real time for antiislet antibodies, characterize pancreatic histology, and obtain viable T cells for immunological studies.

Thymic expression of mutated B16:A preproinsulin messenger RNA does not reverse acceleration of NOD diabetes associated with insulin 2 (thymic expressed insulin) knockout

We detected insulin2 mRNA but not insulin1 in thymus using real-time PCR analysis. Transgenic expression of a mutated insulin message (alanine rather than tyrosine at insulin B chain amino acid 16) was variably induced in thymus of four transgenic founder strains. The transgenic message levels were as high or higher than native insulin2 message. Lack of the insulin2 gene resulted in the enhancement of anti-insulin autoantibodies (regular NOD vs insulin2-knockout NOD, P<0.001) and in the presence of the B16:A insulin transgenes, levels of insulin autoantibodies remained elevated (regular NOD vs insulin2-knockout NOD with B16:A insulin, P<0.01). Diabetes acceleration by the knockout of the insulin2 gene was not influenced by the presence of the B16:A insulin transgenes. These data suggest that the B16:A insulin does not compensate for lack of native insulin expression in thymus. If lack of thymic insulin message of the insulin2 knockout is the cause of diabetes acceleration, this suggests that native insulin B:9-23 sequences may be crucial in thymus for insulin mediated immunomodulation. Further experiments varying native insulin message expression in thymus is necessary for direct comparison, but the current study provides additional evidence of the potential important role of a specific insulin B chain epitope.

Differential immune response to B:9-23 insulin 1 and insulin 2 peptides in animal models of type 1 diabetes

Mice have two insulin genes that differ in the insulin sequence by two amino acids, including the B9 position. Given prior studies of the B:9-23 insulin peptide in NOD mice, a fundamental question is whether the immune response to the B:9-23 peptide of the two insulins is identical. We investigate responses to the immunization with B:9-23 insulin 1 and 2 peptides in NOD and RIP-B7.1 Balb/c mice. NOD and F1 (Balb/c x C57/Bl6) B7.1 transgenic mice were given either B:9-23 insulin 1, B:9-23 insulin 2 or tetanus toxoid (TT) control peptide. Insulin autoantibodies (IAA), and anti-B:9-23 antibodies (IgG1 and IgG2c) were measured. Subcutaneous injection of the insulin 2 but not the insulin 1 peptide significantly protected NOD mice from diabetes. Conceptually similar, insulin 1 peptide immunization accelerated diabetes in the B7.1 mice compared with insulin 2 peptide. Insulin 1 and 2 peptides induced similar levels of IAA in the NOD mice except at week 26, where insulin 2 induced higher levels of IAA. Anti-IgG1 B:9-23 peptide antibodies were higher in the insulin 2 immunized group of NOD mice, while IgG2c anti-B:9-23 peptide antibodies were higher in the insulin 1 group. Adoptive transfer of splenocytes from insulin 1 immunized mice to NOD.scid mice demonstrated accelerated diabetogenicity. The protection afforded by insulin 2 peptide but not insulin 1 peptide in the NOD mouse is reflected by its predominant Th2 humoral response. This may relate to the protection conferred by the insulin 1 knockout when bred onto NOD mice in contrast to acceleration of disease with an insulin 2 knockout.

Prevalence of adrenal antibodies in Addison's disease among north Indian Caucasians

OBJECTIVE

The prevalence of antibodies in different organ-specific autoimmune diseases can vary depending on the racial group studied. Data on the prevalence of antibodies against steroidogenic enzymes in Addison's disease is available only for white Caucasians. We have evaluated the frequency of antibodies against adrenal cytoplasm, 21-hydroxylase, 17-alpha-hydroxylase and side-chain cleavage enzyme in a cohort of Indian patients with Addison's disease of idiopathic and granulomatous aetiology.

DESIGN

Study of all patients with Addison's disease on whom serum samples were available (84% of total), presenting to the Endocrinology Department in a teaching hospital in India, between 1990 and 1999.

PATIENTS

Thirty-eight patients with Addison's disease (19 idiopathic, 19 granulomatous).

METHODS

A radiobinding assay using in vitro transcribed and translated recombinant human 35S-labelled 21-hydroxylase, 17-alpha-hydroxylase and side-chain cleavage enzymes was utilized to detect the respective antibodies. Adrenal cytoplasmic antibodies were measured by indirect immunofluorescence on cryostatic sections of human adrenal cortex.

RESULTS

Of the 19 patients with idiopathic Addison's disease, adrenal cytoplasmic antibodies were present in five (26%) patients, while 21-hydroxylase antibodies were present in four (21%) subjects. The frequency of 21-hydroxylase antibodies was similar among patients with isolated idiopathic Addison's disease (3/13, 23%), and those associated with other organ-specific autoimmune diseases (1/6, 17%). 17-alpha-hydroxylase and side-chain cleavage antibodies were present in four (21%) and three (16%) patients, respectively. Overall, at least one of the three antibodies was present in eight (42%) subjects. All four female patients with premature ovarian failure had antibodies against 17-alpha-hydroxylase and/or side-chain cleavage enzyme. Two (11%) patients with granulomatous Addison's disease had adrenal antibodies. Of these, one patient with enlarged and calcified adrenal gland secondary to tuberculosis had a high titre of antibodies against all three steroidogenic enzymes.

CONCLUSIONS

Antibodies to 21-hydroxylase enzyme are less frequent in idiopathic Addison's disease in north Indians, when compared with other Caucasians. In contrast, the prevalence of 17-alpha-hydroxylase and side-chain cleavage enzyme antibodies is similar to those reported. High titre antibodies against steroidogenic enzymes may occasionally be present in patients with clinical evidence of tuberculous Addison's disease.

The transcription factor SOX9 regulates cell cycle and differentiation genes in chondrocytic CFK2 cells

SOX9 is a transcription factor that is essential for chondrocyte differentiation and cartilage formation. We stably overexpressed SOX9 cDNA in the rat chondrocytic cell line CFK2. Compared with the vector control, a greater proportion of SOX9-transfected cells accumulated in the G0/G1 phase. This was associated with an increase in mRNA and protein expression of p21(cip1), an inhibitor of cyclin-dependent kinase activity. SOX9 enhanced p21(cip1) promoter activity in a luciferase reporter assay. CFK2 cells overexpressing SOX9 became more elongated and adhesive and demonstrated a shift in cytoplasmic F-actin distribution. N-cadherin mRNA levels were elevated in the SOX9-transfected cells, and SOX9 enhanced N-cadherin promoter activity. By electrophoretic mobility shift assay, nuclear extracts of SOX9-transfected CFK2 cells specifically bound an oligonucleotide comprising an N-cadherin promoter region containing a consensus SOX9-binding motif. The transcriptional activity of SOX9 depended upon nuclear localization signals required for SOX9 nuclear entry. Differentiation of transfected CFK2 cells was accelerated as evidenced by more rapid accumulation of alkaline phosphatase activity, increased production of proteoglycans, and increased calcium accumulation, and this was associated with decreased ERK1 expression. These studies demonstrate that SOX9 alters the rate of cell cycle progression of chondrocytes and their differentiation by enhancing or inhibiting the expression of selected genes, including p21(cip1) and ERK1, and that N-cadherin is an additional direct target of this transcriptional regulator.

Parathyroid hormone-related peptide stimulates osteogenic cell proliferation through protein kinase C activation of the Ras/mitogen-activated protein kinase signaling pathway

We investigated the mechanisms of parathyroid hormone-related peptide (PTHrP)-mediated effects on osteogenic cells in primary rat bone marrow cell (BMC) cultures. We first demonstrated by reverse transcriptase-polymerase chain reaction and immunocytochemistry that BMCs express the type I parathyroid hormone/PTHrP receptor. Treatment with PTHrP increased osteogenic cell proliferation as determined by [(3)H]thymidine and bromodeoxyuridine incorporation and augmented osteogenic colonies. Immunocytochemistry and Western blotting revealed no direct effect on expression of the osteoblast markers, type I collagen, bone sialoprotein, and osteocalcin, indicating that PTHrP did not directly stimulate differentiation in this system. PTHrP increased mitogen-activated protein kinase (MAPK) activity in BMC and MAPK activity, and PTHrP-induced osteogenic cell proliferation could be blocked by the MEK inhibitor PD-098059. PTHrP also increased Ras activity in BMC. Although wortmannin and H8, inhibitors of phosphoinositol 3-kinase and protein kinase A, respectively, did not block PTHrP-stimulated Ras or MAPK activity, chelerythrin chloride, a known protein kinase C inhibitor, did block these PTHrP actions as well as PTHrP-induced osteogenic cell proliferation. These results demonstrate that PTHrP stimulates osteogenic cell proliferation in rat marrow mesenchymal progenitor cells through protein kinase C-dependent activation of the Ras and MAPK signaling pathway.

Transient insulin autoantibody expression independent of development of diabetes: comparison of NOD and NOR strains

NOD mice spontaneously develop anti-insulin autoantibodies associated with the subsequent development of diabetes. NOD mice that express insulin autoantibodies at 8 weeks of age have a diabetes risk exceeding 90%, while mice that do not express autoantibodies by 16 weeks have a risk of less than 20%. NOD female mice expressed insulin autoantibodies more often than male mice (13/15+ vs. 6/15+). Autoantibodies characteristically developed between 8 and 20 weeks and then for most mice became negative at diabetes onset in NOD mice. In the diabetes-free strain NOR mice, spontaneous expression of insulin autoantibodies was observed in less mice (female 8/15+, male 3/10+) compared to NOD mice. The expression of autoantibodies was transient in NOR mice and followed the same time-course as for NOD mice and they were all negative by 28 weeks (without progression to diabetes). No correlation was found in NOR mice between the levels of autoantibodies and insulitis. The program of insulin autoantibody expression is regulated over approximately 5 months for both NOD and NOR mice with only NOD mice developing diabetes, indicating that depending upon genetic combination, the presence of insulin autoantibodies does not always predict diabetes development. In addition, this data is not consistent with the hypothesis that the time-course of autoantibodies simply reflects the destruction of beta-cells with development of diabetes.

Targeted ablation of the 25-hydroxyvitamin D 1alpha -hydroxylase enzyme: evidence for skeletal, reproductive, and immune dysfunction

The active form of vitamin D, 1alpha,25-dihydroxyvitamin D [1alpha,25(OH)2D], is synthesized from its precursor 25 hydroxyvitamin D [25(OH)D] via the catalytic action of the 25(OH)D-1alpha-hydroxylase [1alpha(OH)ase] enzyme. Many roles in cell growth and differentiation have been attributed to 1,25(OH)2D, including a central role in calcium homeostasis and skeletal metabolism. To investigate the in vivo functions of 1,25(OH)2D and the molecular basis of its actions, we developed a mouse model deficient in 1alpha(OH)ase by targeted ablation of the hormone-binding and heme-binding domains of the 1alpha(OH)ase gene. After weaning, mice developed hypocalcemia, secondary hyperparathyroidism, retarded growth, and the skeletal abnormalities characteristic of rickets. These abnormalities are similar to those described in humans with the genetic disorder vitamin D dependent rickets type I [VDDR-I; also known as pseudovitamin D-deficiency rickets (PDDR)]. Altered non-collagenous matrix protein expression and reduced numbers of osteoclasts were also observed in bone. Female mutant mice were infertile and exhibited uterine hypoplasia and absent corpora lutea. Furthermore, histologically enlarged lymph nodes in the vicinity of the thyroid gland and a reduction in CD4- and CD8-positive peripheral T lymphocytes were observed. Alopecia, reported in vitamin D receptor (VDR)-deficient mice and in humans with VDDR-II, was not seen. The findings establish a critical role for the 1alpha(OH)ase enzyme in mineral and skeletal homeostasis as well as in female reproduction and also point to an important role in regulating immune function.

Peptide and major histocompatibility complex-specific breaking of humoral tolerance to native insulin with the B9-23 peptide in diabetes-prone and normal mice

NOD mice spontaneously develop anti-insulin autoantibodies and diabetes. A dominant peptide recognized by T-cell clones from NOD mice is insulin B-chain peptide B9-23. When administered subcutaneously to NOD mice, this peptide decreases the development of diabetes. In this study, we evaluated the autoantibody response to native insulin after administration of the B9-23 peptide. In NOD mice, administration of the B9-23 peptide in incomplete Freund's adjuvant enhanced their insulin autoantibody response with a higher level and longer persistence. Induction of insulin autoantibodies with the B9-23 peptide was observed in non-diabetes-prone BALB/c mice and NOR mice within 2 weeks of administration, but this was not observed in C57BL/6 mice. A series of A-chain, other B-chain, and proinsulin peptides did not induce insulin autoantibodies. Induced anti-insulin autoantibodies could not be absorbed with the peptide alone but could be absorbed with native insulin. The B13-23 peptide (one of two identified epitopes within B9-23) when administered to BALB/c mice, induced autoantibodies, whereas peptide B9-16 did not. Induction of autoantibodies mapped to the major histocompatibility complex (MHC) rather than to the background genes. Both splenocytes with I-A(d)/I-E(d) or I-A(g7)/I-E(null) presented the B9-23 peptide to NOD islet-derived T-cell clones. Finally, administration of the B9-23 peptide to BALB/c mice, even without adjuvant, could induce insulin autoantibodies. Our results indicate that B-cell tolerance to intact insulin is readily broken with the presentation of the B9-23 insulin peptide, depending on the host's specific MHC.

Tissue-specific targeting of the pthrp gene: the generation of mice with floxed alleles

PTH-related peptide (PTHrP) has been implicated in a variety of developmental and homeostatic processes. Although mice homozygous for the targeted disruption of the Pthrp gene have greatly expanded our capacity to investigate the developmental roles of the protein, the perinatal lethality of these animals has severely hindered the analysis of Pthrp's postnatal physiological effects. To overcome this obstacle, we have generated mice homozygous for a floxed Pthrp allele, i.e. two loxP sites flanking exon 4 of the Pthrp gene, which encodes most of the protein, with the aim of accomplishing cell type- and tissue-specific deletion of the gene. The ability of the Cre enzyme to cause recombination between the loxP sites and excision of the intervening DNA sequence was tested in vivo by crossing this strain to mice carrying a cre transgene under the transcriptional control of the human beta-actin promoter. The ubiquitous deletion of the floxed allele in the cre/loxP progeny resulted in perinatal lethality as a consequence of aberrant endochondral bone formation, fully recapitulating all the phenotypic abnormalities observed in the conventional Pthrp knockout mouse. The availability of the floxed Pthrp mice will serve as a valuable tool in genetic experiments that aim to investigate the physiological actions of Pthrp in the postnatal state.

Osteomalacia in hyp mice is associated with abnormal phex expression and with altered bone matrix protein expression and deposition

To explore how the loss of Phex function contributes to the pathogenesis of osteomalacia, we examined the abnormalities of mineralization, Phex, and bone matrix protein expression occurring in Hyp mice in vivo and in ex vivo bone marrow cell cultures. The results in vivo show that mineralization was decreased significantly in Hyp mouse bone. Phex protein was identifiable in osteoblasts and osteocytes in wild-type mice, but not in Hyp mice. In Hyp mice, osteocalcin, bone sialoprotein, and vitronectin expression were down-regulated, whereas biglycan and fibrillin-1 expression were up-regulated in osteocytes and bone matrix relative to those in their wild-type counterparts. Parallel studies ex vivo demonstrated that cells derived from 18-day Hyp mouse bone marrow cell cultures had a 3'-Phex deletion, no Phex protein expression, decreased alkaline phosphatase activity, collagen deposition, and calcium accumulation, and reduced osteocalcin, bone sialoprotein, and vitronectin at both the protein and messenger RNA levels. Furthermore conditioned medium from Hyp mouse bone marrow cultures could induce analogous defects in bone marrow cell cultures of wild-type cells. These novel findings indicate that there is an intrinsic osteogenic cell differentiation defect in addition to the known hypomineralization of bone in Hyp mice, which may be inducible by an autocrine/paracrine secreted factor. These results suggest that alterations in the Phex gene may control bone matrix mineralization indirectly by regulating the synthesis and deposition of bone matrix proteins.

Rapid assays for detection of anti-islet autoantibodies: implications for organ donor screening

The purpose of the current study was to develop and evaluate rapid assays for autoantibodies to GAD65 (GAA), ICA512bdc/IA-2 (ICA512AA), and insulin (microIAA, mIAA) as a potential tool for identification of cadaveric pancreas donors who were at high risk for developing diabetes. The study included 154 new onset diabetic, prediabetic, and healthy control subjects. Subjects were evaluated for all three autoantibodies in three separate assays: (1) standard (std) assay with a 24-h or 72-h incubation at 4 degrees C (combined GAA/ICA512AA or mIAA, respectively), (2) rapid assay with 1-h room temperature (RT) incubation, and (3) rapid assay with 2-h RT incubation. The serum samples from 777 organ donors were also evaluated for all three autoantibodies and all the positive samples from standard assay evaluated with the 1-h incubation assay. Simple linear regression analyses revealed excellent correlation between the standard assay and the rapid assays for all three autoantibodies, as follows: (1) GAA: std vs. 1 h (R2=0.85) and std vs. 2 h (R2=0.83), (2) ICA512AA: std vs. 1 h (R2=0.85) and std vs. 2 h (R2=0.84), and (3) mIAA: std vs. 1 h (R2=0.70) and std vs. 2 h (R2=0.64). Comparison of assay correlation rates between subject cohorts revealed no significant differences. Compared to their respective standard assays, the 1-h RT GAA assay missed 3.2% and identified an additional 1.3% of samples, the 1-h RT ICA512AA assay had no discordant samples, and the 1-h RT mIAA assay missed 7.1% and identified an additional 5.8% of samples. We analysed a series of 777 stored serum samples from cadaveric donors. Two of 777 (0.25%) were positive for two autoantibodies (both GAA and ICA512AA) and 23 of 777 (3.0%) one autoantibody (11 IAA; 12 GAA). The rapid analysis for all three autoantibodies could be completed in less than 3 h with comparable concordance rates to the more time-consuming standard assays, making these assays an attractive option for organ donor screening to identify potential pancreata for immunopathogenetic research.

[Validity of Sternberg dualtask in evaluating flight ability and effect of educational factor]

Validity of the Sternberg dualtask (tracking task and remember) for evaluating flight ability of military pilots, and the influencing factors were studied in 112 grade pilots with different educational levels, ages and kinds of planes. The evaluations of their flight ability were made by their leaders using the multiple-criterion evaluation system. The results showed: the Sternberg dualtask can be used to evaluate the abilities of rapid reaction of operating fighters; the influence of the educational level and age should be considered during evaluating flight ability. It suggests that the Sternberg dualtask is very effective in evaluating flight ability, and it shows that fighter pilots with high educational level, age from 25 to 29, are best candidates for astronauts in China.

Characteristics of nystagmus and illusion evoked by optokinetic stimuli

To study the characteristics of human psychophysiological responses to optokinetic stimulus, 30 male medical students were given a series of optokinetic step stimulus (5, 10, 15, 20, 30, 40, 60, 80, 100, 120 deg/sec ) (clockwise). Each stimulus lasted for 20 seconds. Optokinetic nystagmus was recorded on tape. At the same time, the latency and estimated fuzzy magnitude of the illusion were noted down. The nystagmus was analysed with a computer system of ENG and the magnitude of illusion was measured with a fuzzy set model. The results were: 1. Both the slow velocity (SV) and fast velocity (FV) of optokinetic nystagmus increased as stimulus speeded up and reached their peaks at 60 deg/sec, which remained constant from 60 to 120 deg/sec; 2. From 5 to 120 deg/sec, the magnitude of optokinetic illusion increased linearly as stimulus speeded up. Optokinetic illusion and optokinetic nystagmus are human psychophysiological responses to the same optokinetic stimulus, they are different in trend of change, and when optokinetic stimulus is at 60-l20 deg/sec, illusion response is more stable than nystagmus response.

Short-term treatment of rats with high dose 1,25-dihydroxyvitamin D3 stimulates bone formation and increases the number of osteoblast precursor cells in bone marrow

Using an experimental rat model, this study was undertaken to assess the effects of a short-term application of high dose 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] on calcium homeostasis, cancellous bone formation, and numbers of osteoblast precursors in ex vivo bone marrow cultures. For Exp 1 and 2, 6-month-old female rats were sc injected with either 0.2 microg 1,25-(OH)2D3/kg x day or vehicle on days 1, 2, and 3 of the studies. Serum calcium and urinary excretion of calcium were monitored for 12 days in Exp 1. In Exp 2, the rats were ip labeled with five different fluorochromes on days 0, 5, 10, 15, and 20, respectively. Half of the rats in each group were killed on day 7, the rest of the rats were killed on day 24, and the first lumbar vertebrae were processed for histomorphometry. In Exp 3, 0.2 microg 1,25-(OH)2D3/kg BW or vehicle was sc administered to 6-month-old male rats on days 1, 2, and 3, and the number of colony-forming units with the ability to express alkaline phosphatase, to calcify, and/or to synthesize collagen were enumerated sequentially on days 4, 6, 8, 10, 12, and 14 in bone marrow cultures. Short-term 1,25-(OH)2D3 treatment resulted in increased values for serum and urinary calcium during the treatment phase in Exp 1, depressed osteoclast numbers and strongly elevated osteoblast perimeter by day 7, and stimulated mineral apposition rate and bone formation rate in the interval between days 5-15 of Exp 2. Moreover, 1,25-(OH)2D3 administration to rats significantly enhanced the number of mesenchymal precursor cells in bone marrow with the ability to differentiate into an osteoblastic phenotype in ex vivo bone marrow cultures on day 4 of Exp 3. These studies provide evidence that short-term 1,25-(OH)2D3 treatment creates new bone remodeling units and augments osteoblast recruitment and osteoblast team performance in rat cancellous bone.

The effects of human seminal plasma and PGE2 on mitogen induced proliferation and cytokine production of human splenic lymphocytes and peripheral blood mononuclear cells

The effects of human seminal plasma (HSP) and prostaglandin E2 (PGE2) on the proliferative responses of human splenic lymphocytes and peripheral blood mononuclear cells (PBMCs) to phytohaemagglutinin (PHA), anti-CD3 and anti-CD3 plus anti-CD28 mAb have been studied. Th1 and Th2 cytokines were also measured in the supernatants of selected cultures. Both HSP and PGE2 reproducibly inhibit the proliferative response to PHA and anti-CD3 mAb in a dose dependent manner. These effects were observed with both fresh and frozen human PBMCs and splenic lymphocytes. HSP and PGE2 however were less effective in inhibiting the co-stimulatory response induced by anti-CD3 plus anti-CD28 mAb. In addition, the HSP and PGE2 treatment used inhibited the production of the Th1 cytokines IL-2 and IFNg but had a differential modulatory effect on Th2 cytokine production, namely enhancing the production of IL-6 whilst simultaneously impairing the synthesis of IL-4 and IL-10.

Mutational analysis of the specific priming signal essential for DNA replication of the broad host-range plasmid RSF1010

To analyze the RSF1010-specific priming mechanism, a library of randomly mutagenized ssiA sequences was constructed by chemical synthesis using mixed nucleotide phosphoramidites. Synthetic ssiA sequences with the single base-substitutions were assayed for the SSI activity in E. coli JM109 expressing RepB' primase. It was demonstrated that the activity of ssiA was damaged markedly by single base-substitutions within the possible stem-loop structure and its 3'-flanking region. It is conceivable that these domains are critical in recognition and primer synthesis by RepB' primase.