Intrinsic mineralization defect in Hyp mouse osteoblasts

X-linked hypophosphatemia (XLH) is caused by inactivating mutations of PEX, an endopeptidase of uncertain function. This defect is shared by Hyp mice, the murine homologue of the human disease, in which a 3' Pex deletion has been documented. In the present study, we report that immortalized osteoblasts derived from the simian virus 40 (SV40) transgenic Hyp mouse (TMOb-Hyp) have an impaired capacity to mineralize extracellular matrix in vitro. Compared with immortalized osteoblasts from the SV40 transgenic normal mouse (TMOb-Nl), osteoblast cultures from the SV40 Hyp mouse exhibit diminished 45Ca accumulation into extracellular matrix (37 +/- 6 vs. 1,484 +/- 68 counts . min-1 . microgram protein-1) and reduced formation of mineralization nodules. Moreover, in coculture experiments, we found evidence that osteoblasts from the SV40 Hyp mouse produce a diffusible factor that blocks mineralization of extracellular matrix in normal osteoblasts. Our findings indicate that abnormal PEX in osteoblasts is associated with the accumulation of a factor(s) that inhibits mineralization of extracellular matrix in vitro.

[Synthesis of hirudin variant 1 (HV1) gene and primary study of expression in yeast]

OBJECTIVE

Hirudin is an extremely efficient and specific thrombin inhibitor. It is clinically used to prevent the formation of thrombus. In this research the hirudin gene was put into yeast system for expression to evaluate the feasibility of artificially synthesized gene expressed in eukaryotic system and study the factor affecting expression level.

METHODS

According to the amino acid sequence of hirudin variant 1 (HV1), the genetic code saccharomyces cerevisiae was used to design and synthesize the HV1 gene. Amplified by PCR, it was inserted into cloning vector pBS-SK(+) and sequenced. Ligation with the signal peptide gene of yeast alpha factor the correct HV1 gene was inserted into yeast expression vector pYC-DE. The recombinant plasmid was transformed into the cell of S. cerevisiae BJ1990 to carry out the primary expression experiment.

RESULTS

In cultured supernatant of screened positive clone the hirudin activity was detected to be 30 ATU/ml. The expression level was higher than HV2 in yeast and HV1 in prokaryotic system. The N terminal amino acid sequence completely matches with natural hirudin.

CONCLUSIONS

It was proved by this study that the synthesized hirudin gene had been expressed in yeast successfully. This result showed that it was a better way to carry out the expression in yeast using synthesized HV1 gene and a stronger promoter.

LIGHT, a novel ligand for lymphotoxin beta receptor and TR2/HVEM induces apoptosis and suppresses in vivo tumor formation via gene transfer

LIGHT is a new member of tumor necrosis factor (TNF) cytokine family derived from an activated T cell cDNA library. LIGHT mRNA is highly expressed in splenocytes, activated PBL, CD8(+) tumor infiltrating lymphocytes, granulocytes, and monocytes but not in the thymus and the tumor cells examined. Introduction of LIGHT cDNA into MDA-MB-231 human breast carcinoma caused complete tumor suppression in vivo. Histological examination showed marked neutrophil infiltration and necrosis in LIGHT expressing but not in the parental or the Neo-transfected MDA-MB-231 tumors. Interferon gamma (IFNgamma) dramatically enhances LIGHT-mediated apoptosis. LIGHT protein triggers apoptosis of various tumor cells expressing both lymphotoxin beta receptor (LTbetaR) and TR2/HVEM receptors, and its cytotoxicity can be blocked specifically by addition of a LTbetaR-Fc or a TR2/HVEM-Fc fusion protein. However, LIGHT was not cytolytic to the tumor cells that express only the LTbetaR or the TR2/HVEM or hematopoietic cells examined that express only the TR2/HVEM, such as PBL, Jurkat cells, or CD8(+) TIL cells. In contrast, treatment of the activated PBL with LIGHT resulted in release of IFNgamma. Our data suggest that LIGHT triggers distinct biological responses based on the expression patterns of its receptors on the target cells. Thus, LIGHT may play a role in the immune modulation and have a potential value in cancer therapy.

RT-PCR study of the distribution of connexin 43 mRNA in the glomerulus and renal tubular segments

An RT-PCR study of the distribution of connexin 43 (Cx43) mRNA in glomeruli and along the rat tubular segments was carried out to establish the differential expression of Cx43 in the different segments of the tubule, in renal regions, in isolated glomerular preparations (IGP), and in microdissected glomeruli. The mRNA level of Cx43 in macrodissected renal regions appeared in the following order: inner papilla > outer papilla and IGP > outer medulla and cortex. Among the microdissected tubules, inner medullary collecting ducts (IMCD) expressed the highest level of Cx43 mRNA, followed by the cortical collecting ducts (CCD). The proximal convoluted tubules and proximal straight tubules expressed significantly less Cx43 than the IMCD, glomeruli, and CCD. Medullary thick ascending limb and distal convoluted tubules showed the lowest level of Cx43 mRNA. The RT-PCR results of the microdissected segments correlate well with those obtained by RT-PCR of the renal regions. The high concentration of Cx43 mRNA in the IMCD together with the observation of abundant punctate immunofluorescence for Cx43 suggests that the IMCD not only expresses Cx43 mRNA but also that the mRNA is translated to Cx43 protein.

Monitoring of acute allograft rejection by cytological, immunocytochemical, and immunohistochemical studies following rat small-bowel transplantation

We investigated the role of graft luminal fluid cytology for immunological monitoring of rat small-bowel allograft recipients. Allogeneic transplantation from WKAM (RT1u) to Lewis recipients and syngeneic transplantation using Lewis (RT11) rats were carried out. Twenty centimeters of the proximal jejunum was transplanted as a Thiry-Vella loop. The luminal fluid on days 0, 3, and 6 was examined cytologically using Papanicolaou, periodic acid-Schiff, and Giemsa staining, and immunocytochemically with monoclonal antibodies for macrophages (ED1 and ED2). Full thickness biopsies of graft tissue were evaluated by both immunofluorescence (ED1 and ED2) and by standard histological methods. The cytological examination on day 6 revealed an increase in the number of enterocytes, lymphocytes, and neutrophils, the presence of bacteria, and the depletion of goblet cells in the allografts. Histologically, significant morphological changes of acute rejection were first seen on day 6. Immunofluorescence predicted the acute rejection of the allografts earlier than a histological examination by showing an increase in the number of ED1- and Ed2-positive cells on day 3. Graft luminal fluid cytology and immunofluorescence analysis of ED1 and ED2 cells could thus be used to recognize early acute allograft rejection following small-bowel transplantation.

[The construction of poliovirus chimera and the analysis of its antigenic structure]

The construction of poliovirus chimera is an useful way to investigate the antigenic structure conformation of poliovirus. In this research, the poliovirus chimera containing a piece of antigenic fragment of hepatitis A virus was constructed for analysis of poliovirus antigenic structure conformation. Depending on the characterization of this chimera, the conformation of poliovirus neutralization antigenic site I in VP1 was analyzed, and that the possible influence of hepatitis A virus antigenic fragment inserted to the structure conformation of poliovirus antigen was also investigated.

Cellular composition and anatomic distribution in nonfunctioning pancreatic endocrine tumors: immunohistochemical study of 30 cases

OBJECTIVE

To investigate the cytological pattern and distribution in nonfunctioning pancreatic endocrine tumors.

METHODS

Using labeled streptavidin-biotin (LSAB), immunohistochemical staining for insulin, glucagon, somatostatin, pancreatic polypeptide and gastrin was performed on 30 nonfunctioning pancreatic endocrine tumors from 30 patients. The cellular composition and anatomic distribution in these tumors were analyzed.

RESULTS

Of 30 tumor tissues, 22 (73.3%) were found to contain cells immunoreactive to 1-4 kinds of peptide hormones; 17 (56.7%) showed positive staining for more than one peptide and up to 4 peptides; and 8 (26.7%) showed negative immunoreaction to all antiserum applied. No tumor was found to contain immunoreactive gastrin. Among 17 multihormonal tumors, 4 contained 2 kinds of peptide hormones, 8 had 3 kinds, and 5 harbored 4 kinds of peptide hormones. In addition, the difference in the number and type of positive endocrine cells between the tumors arising from the head of the pancreas and those arising from the body and tail of the pancreas were statistically significant (P < 0.05).

CONCLUSIONS

Immunohistochemically, the high positive rate to peptide hormones suggests that the nonfunctioning pancreatic endocrine tumors are actually not nonfunctioning; they are asymptomatic pancreatic endocrine tumors. Moreover, an uneven distribution of positive endocrine cells in the nonfunctioning pancreas endocrine tumors within the pancreas was identified.

[Determination of paeonol in jiawei xiaoyao granules by HPLC]

A HPLC method has been used for the determination of paeonol in Jiawei Xiaoyao Granules. The method is simple and accurate. The average recovery is 96.48% and relative standard deviation 1.11%. The method can be used for quantitative analysis of these granules.

[PCR in detecting the correlation between infection of HBV and cholelithiasis]

OBJECTIVE

To study the correlation between cholelithiasis and the infection of HBV.

METHOD

32 formalin-fixed and paraffin-embedded gallbladder samples of cholelithiasis patients and 20 gallbladder samples of non-cholelithiasis patients were investigated using the polymerase chain reaction-Ethidium bromide (PCR-EB) assay. The 52 patients were positive to HBV serologic markers.

RESULT

The results showed that HBV-DNA was found in 13 gallbladder samples of 32 cholelithiasis patients (40.63%), significantly higher than that in 3 gallbladder samples of 20 non-cholelithiasis patients (15%).

CONCLUSION

The infection of HBV and the formation of cholelithiasis are correlated.

[The analysis of donkey-hide glue, antler glue and tortoise shell glue by means of circular dichroism]

Donkey-hide glue, antler glue, tortoise shell glue and their forgeries were identified by the analysis method of circular dichroism(CD) in this paper. The standard spectra and data were set up. The method is simple, fast and accurate.

[The observation on infection of trasgenic mice (PVR Tg21) with polioviruses type 3]

OBJECTIVE

To test and verify whether PVR Tg21 transgenic mice can be used as an animal model or not.

METHODS

PVR Tg21 transgenic mice were infected with 3 poliovirus strains with different neurovirulence intraspinally.

RESULTS

All the mice showed clinical paralysis with characteristic lesions in neurons. The symptoms varied with different potency of virus. The onset of clinical paralysis time for inoculated mice were approximately 2 days with Leon virus, 5 days with Sabin strain, and 4 days with Vaccine-321. More than 90% of mice inoculated with Leon strain died within 3 days after clinical paralysis and only 35% mice inoculated with Sabin-3 died at average of 6 days, and the PD50 are 10(1.1), 10(2.6), and 10(4.97) TCID50 and LD50 are 10(1.1), 10(3.33) and 10(5.33) TCID50, respectively. Different virus inoculated intraspinally caused different histopathological lesions.

CONCLUSIONS

The PVR Tg21 transgenic mice could be a new animal model for neurovirulent evaluation of poliovaccines and epidemiological surveillance.

Physical localization of rRNA genes by two-colour fluorescent in-situ hybridization and sequence analysis of the 5S rRNA gene in Phalaris coerulescens

The 18S-5.8S-26S rDNA and 5S rDNA loci have been mapped physically by fluorescent in-situ hybridization to the chromosomes of Phalaris coerulescens. The biotin-labelled heterologous 18S-5.8S-26S rRNA probe (pTa71) detected one locus, which corresponded to the secondary constriction (nucleolar organizer) on the long arm of the satellited chromosome II. The homologous 5S rDNA probe (Bam2.12) detected two pairs of 5S rRNA gene clusters which were localized at two different non-satellited chromosomes, one near the telomere on the short arm of the chromosome I, which is the largest chromosome of the complement, and the other about 42% out on the long arm of the chromosome III. A BamHI fragment containing the 5S rRNA gene, has been isolated and characterized. The 5S rDNA repeat unit is 309 bp in length, consisting of 121 bp highly conserved coding region and 188 bp variable spacer region. The karyotype of Phalaris coerulescens is characterized by the similar size of chromosomes within the group 2, group 3, or group 4. This study represents the first step towards the understanding the genome organization of Phalaris coerulescens and provides reliable markers for chromosome identification in this grass, an important species as a model system for the study of self-incompatibility in grasses.

[Determination of geniposide and paeoniflorin in Jiawei Xiaoyao Pills by HPLC]

The geniposide and paeoniflorin in Jiaowei Xiaoyao Pills were separated and determined by HPLC, with a C18 column and a mixture of CH3CN-0.1% H3PO4(13:87) as mobile phase. The method is simple, rapid and accurate. The components have a good linearity, and the average recovery with RSD(n = 5) is 101.81% + 2.38% for geniposide and 98.75% + 1.95% for paeoniflorin.

Putative analgesic activity of repeated oral doses of vitamin E in the treatment of rheumatoid arthritis. Results of a prospective placebo controlled double blind trial

OBJECTIVE

Vitamin E, the most potent naturally occurring lipid soluble antioxidant has been suggested to possess both anti-inflammatory and analgesic activity in humans. This double blind and randomised study used a broad spectrum of clinical and laboratory parameters to investigate whether there was any additional anti-inflammatory or analgesic effects, or both, of orally administered alpha-tocopherol in rheumatoid arthritis patients who were already receiving anti-rheumatic drugs.

METHODS

Forty two patients were enrolled and treated with alpha-tocopherol (n = 20) at a dose of 600 mg twice a day (2 x 2 capsules) or with placebo (n = 22) for 12 weeks. The following parameters were measured: (1) Three clinical indices of inflammation--the Ritchie articular index, the duration of morning stiffness, and the number of swollen joints; (2) three measures of pain--pain in the morning, pain in the evening, and pain after chosen activity; (3) haematological and biochemical measures of inflammatory activity; (4) assays for the oxidative modification of proteins and lipids.

RESULTS

All laboratory measures of inflammatory activity and oxidative modification were unchanged. Furthermore, the clinical indices of inflammation were not influenced by the treatment. However, the pain parameters were significantly decreased after vitamin E treatment when compared with placebo.

CONCLUSION

The results provide preliminary evidence that vitamin E may exert a small but significant analgesic activity independent of a peripheral anti-inflammatory effect, but which complements standard anti-inflammatory treatment.

Cloning and sequencing of human PEX from a bone cDNA library: evidence for its developmental stage-specific regulation in osteoblasts

Inactivating mutations of the neutral endopeptidase, PEX, have been identified as the cause of X-linked hypophosphatemia (XLH). Though the function of PEX is unknown, current information suggests that impaired renal phosphate conservation in XLH is due to the failure of PEX to either degrade an undefined phosphaturic factor or activate a novel phosphate-conserving hormone. The physiologically relevant target tissue for the XLH mutation has not been identified. An apparent intrinsic defect of osteoblast function in XLH implicates bone as a possible site of PEX expression. In the current investigation, we employed a polymerase chain reaction (PCR) strategy to amplify a PEX cDNA from a human bone cell cDNA library. We found that the human PEX cDNA encodes a 749 amino acid protein belonging to the type II integral membrane zinc-dependent endopeptidase family. The predicted PEX amino acid sequence shares 96.0% identify to the recently cloned mouse Pex cDNA and has 27-38% identity to other members of the metalloendopeptidase family. Using reverse transcriptase (RT)-PCR with PEX-specific primers, we detected PEX transcripts in both human osteosarcoma-derived MG-63 osteoblasts and in differentiated mouse MC3T3-E1 clonal osteoblasts but not in immature MC3T3-E1 preosteoblasts. The association of impaired mineralization of bone in XLH and the apparent developmental stage-specific expression of PEX in osteoblasts suggest that bone is a physiologically relevant site of PEX expression and that PEX may play an active role in osteoblast-mediated mineralization.

A distinct cation-sensing mechanism in MC3T3-E1 osteoblasts functionally related to the calcium receptor

The presence of a cation-sensing mechanism in osteoblasts is suggested by the ability of specific cations to stimulate osteoblastic proliferation in culture and to induce de novo bone formation in some experimental models. Our study examines whether extracellular cations stimulate osteoblasts through the recently identified G protein-coupled calcium receptor (CaR). We found that CaR agonists, calcium (Ca2+), gadolinium (Gd3+), aluminum (Al3+), and neomycin, stimulated DNA synthesis in murine-derived MC3T3-E1 preosteoblasts, whereas magnesium (Mg2+), nickel (Ni2+), cadmium (Cd2+), and zinc (Zn2+) had no effect. With the exception of Mg2+, the cation specificities and apparent affinities were similar to that reported for CaR. CaR agonists also stimulated DNA synthesis in C3HT10(1/2) fibroblasts, but not in mesangial PVG, CHO, hepatic HTC, COS-7 cells, or malignant transformed ROS17/2.8 and UMR-106 osteoblasts. In addition, similar to other growth factors, CaR agonists activated transcription of a serum response element luciferase reporter construct (SRE-Luc) stably transfected into MC3T3-E1 osteoblasts, but had no effect on SRE-Luc transfected into CHO and COS-7 cells. We were unable to detect CaR expression by Northern analysis using a mouse CaR-specific probe or to amplify CaR mRNA by reverse transcribed polymerase chain reaction in MC3T3-E1 osteoblasts. These findings suggest that an extra-cellular cation-sensing mechanism is present in murine-derived osteoblasts that is functionally similar to but molecularly distinct from CaR.

The distribution and co-localization of nitric oxide synthase and vasoactive intestinal polypeptide in nerves of the colons with Hirschsprung's disease

The distribution and co-localization of nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) were examined by means of immunohistochemistry and NADPH diaphorase (NADPH-d) histochemistry in the gut of patients with Hirschsprung's disease. In the normoganglionic segment, many nitrergic nerve cells were localized in Auerbach's plexus and nerve fibres were observed preferentially in the circular muscle. The submucosal nitrergic nerve cells were mainly situated in Schabadasch's plexus with occasional cells demonstrable in Meissner's plexus. NOS and VIP were co-localized in most ganglion cells of Auerbach's plexus. In the oligoganglionic segment, a marked reduction of NOS- and VIP- positive nerve cells and fibres was noticed in both the myenteric and submucosal plexuses, and nitrergic fibres had disappeared in the inner layer of the circular muscle. In the aganglionic segment, NOS and VIP were revealed only in extrinsic nerve fasciculi and rami and co-localized in a few fibres. From these observations, the inner layer of the circular muscle of the oligoganglionic segment and the whole of the muscularis propria of the aganglionic segment were considered to be totally lacking in nitrergic innervation. Nitrergic nerves of the human colon comprise both intrinsic and extrinsic elements and the majority of intrinsic nitrergic nerve cells contain VIP. Very low numbers of extrinsic nitrergic fibres contain VIP.

The morphologic characteristics of flail mitral leaflets by transesophageal echocardiography

BACKGROUND AND AIMS OF THE STUDY

Mitral valve prolapse due to floppy mitral valve (MVP/FMV) is a common valvular abnormality with a variable clinical course. Flail mitral valve leaflet resulting in severe mitral regurgitation is a complication of MVP/FMV.

METHODS

In order to understand the structural correlates of flail mitral valve leaflet in MVP, we reviewed the morphologic characteristics of the mitral valve by transesophageal echocardiography (TEE) in 72 patients (24 normal; 26 mitral valve prolapse; 22 flail mitral valve leaflet).

RESULTS

Compared with the normal group, the mitral valve prolapse group had greater anterior and posterior mitral valve leaflet thickness and anterior mitral valve leaflet length. Patients with flail mitral valve leaflets as a complication of FMV had greater anterior and posterior mitral valve leaflet length and posterior mitral valve leaflet thickness compared with MVP patients without flail mitral valve leaflets. Posterior mitral valve leaflet length was the only echocardiographic independent predictor of flail mitral valve leaflet. Older FMV patients with increased mitral valve leaflet length and thickness are predisposed to flail mitral valve leaflets and severe mitral regurgitation.

CONCLUSIONS

TEE may identify patients with MVP/FMV with the greatest structural abnormalities who are at risk for complications such as flail mitral valve leaflet(s).

Relationship between high incidence of adverse dapsone reactions and slow acetylate phenotype or low plasma/lymphocyte glutathione level

OBJECTIVE

To investigate the relationship between high incidence of adverse dapsone reactions in acquired immunodeficiency syndrome (AIDS) patients and slow acetylate phenotype or low plasma/lymphocyte glutathione level of these patients.

METHODS

Twenty-one cases of advanced AIDS patients (CD4 < 200/microliter) were involved in this study, all Europeans except one black, were acetylate phenotyped via analysis of caffeine metabolites, named 5-Acetylamino-6-formylamino-3-methyluracil, 1-Methylxanthine and 5-Acetylamino-6-amino-3-methyluracil, in human urine collected 2 hours after a cup of caffeine-spiked coffee and their plasma/lymphocyte glutathione concentrations were determined, by high performance liquid chromatographic method.

RESULTS

Of the 21 AIDS patients, 15 are slow acetylators, accounting for 74.8%. One of 6 rapid acetylators has adverse dapsone reactions, acounting for 17%, compared with 46% for slow acetylators (7/15). The concentrations of glutathione in plasma/lymphocyte (6.97 +/- 0.95 mumol and 28.75 +/- 2.78 nmol/mg protein) in AIDS patients with adverse dapsone reactions are significantly lower than those (10.90 +/- 1.45 mumol and 32.15 +/- 2.21 nmol/mg protein) of AIDS patients without adverse dapsone reactions, and also than those (11.85 +/- 1.83 mumol and 33.76 +/- 2.32 nmol/mg protein) of health controls.

CONCLUSIONS

Slow acetylators, which lead to accumulation of toxic dapsone metabolites and those subjects who are lower in glutathione level in plasma/lymphocyte because of certain kind of diseases as advanced AIDS are risk population of adverse dapsone reactions. Routinely determining human acetylate phenotype status might be helpful in adjusting and modifying dapsone dosage regimen.

Peroxylated and hydroxylated uroporphyrins: a study of their production in vitro in enzymic and chemical model systems

In previous work certain hydroxylated and peroxylated derivatives of uroporphyrin (URO) have been isolated from the urine of patients suffering from porphyria. We have now investigated the mechanism of production of these oxygenated derivatives of URO, using both enzymic and chemical model systems and also the effect of exposure to light during reoxidation of uroporphyrinogen (URO'gen). When URO'gen was incubated with haemolysates, peaks with the same retention times as peroxyacetic acid URO, meso-hydroxy URO and beta-hydroxypropionic acid URO were all detected. The first of these was formed in sufficient amounts to allow its characterization by mass spectrometry. Under these conditions, peroxyacetic acid derivatives of heptacarboxylate and pentacarboxylate porphyrins could also be produced from the corresponding porphyrinogens, but no peroxylated product could be obtained from coproporphyrinogen (COPRO'gen, where no acetic acid side chains are present) or from the fully oxidized URO. Similar results were obtained on re-oxidation of URO'gen in the xanthine oxidase-xanthine system and in the presence of hydrogen peroxide/Fe-EDTA (ethylenediamine-tetraacetic acid) and here again no peroxylated product could be detected from either COPRO'gen or URO. Finally, formation of peroxyacetic acid URO could be demonstrated during photo-oxidation of URO'gen and this was followed by light-induced loss of both URO and its peroxylated derivative. It is concluded that the oxygenated derivatives arise from the action of reactive oxygen species on the porphyrinogens (rather than the porphyrins), with one of the acetic acid side chain serving as the preferential (or exclusive target) for peroxylation.