Bone marrow cells can give rise to ameloblast-like cells

Post-eruptive loss of ameloblasts requires identification of alternative sources for these cells to realize tooth-tissue-engineering strategies. Recent reports showed that bone-marrow-derived cells can give rise to different types of epithelial cells, suggesting their potential to serve as a source for ameloblasts. To investigate this potential, we mixed c-Kit(+)-enriched bone marrow cells with embryonic dental epithelial cells and cultured them in re-association with dental mesenchyme. Non-dividing, polarized, and secretory ameloblast-like cells were achieved without cell fusion. Before basement membrane reconstitution, some bone marrow cells migrated to the mesenchyme, where they exhibited morphological, molecular, and functional characteristics of odontoblasts. These results show, for the first time, that bone-marrow-derived cells can be reprogrammed to give rise to ameloblast-like cells, offering novel possibilities for tooth-tissue engineering and the study of the simultaneous differentiation of one bone marrow cell subpopulation into cells of two different embryonic lineages.

Temperature variation of film tension above the bulk smectic-A-isotropic transition in freestanding liquid-crystal films

We have measured the temperature variation of film tension above the bulk smectic-A-isotropic transition in freestanding films of two liquid-crystal compounds. Above the transition, the tension increases sharply with temperature, and the slope is proportional to the film's thickness regardless of whether or not the compound exhibits regular layer-by-layer thinning. The data can be interpreted in the context of theoretical models for layer thinning.

Study on the relation between occupational fenvalerate exposure and spermatozoa DNA damage of pesticide factory workers

AIMS

To determine sperm nuclear DNA integrity and to investigate the relation between fenvalerate (FE) exposure and spermatozoa DNA damage.

METHODS

Sperm DNA fragmentation was detected by a modified alkaline single cell gel electrophoresis (Comet) assay and a terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL) assay. The olive tail moment (OTM) and percentage tail DNA were measured by the Comet assay, and cell positive percentage was measured by the TUNEL assay for DNA damage evaluation.

RESULTS

The DNA integrity of spermatozoa of external and internal control groups were both significantly greater than that of the FE exposed group. The median value of tail DNA percentage in the exposure group was 11.30, which was significantly higher than 5.60 in the internal control group and 5.10 in the external control group. The median value of OTM was 3.80 in the exposure group, significantly higher than 1.50 in the internal control group and 2.00 in the external control group. Mean cell positive was 31.2% in the exposure group, significantly higher than 17.4% in the internal control and 19.6% in the external control groups. Cell positive (%) was significantly correlated with tail DNA percentage and with OTM of whole subjects (n = 63).

CONCLUSIONS

Results showed that occupational FE exposure is associated with an increase in sperm DNA damage. A combination of the Comet and TUNEL assays would offer more comprehensive information for a better understanding of sperm DNA damage, and the biological significance of sperm DNA damage in sperm function and male infertility.

Destruction of parotid glands affects nitrate and nitrite metabolism

The role of salivary glands in nitrate and nitrite metabolism is poorly understood. The aim of the present study was to investigate the effect of parotid gland ablation on dynamic metabolism of nitrate and nitrite in miniature pigs. The parotid glands of 5 healthy miniature pigs were bilaterally ablated by methyl violet. Concentrations of nitrate and nitrite of whole saliva, serum, and urine samples were analyzed by high-performance liquid chromatography. Results showed that bilateral ablation of the parotid glands led to a significant decrease of nitrate secretion from blood to saliva (P < 0.05) and thus low nitrite levels. Dysfunction of the parotid glands temporarily increased the systemic level of nitrate in miniature pigs after nitrate loading. This study suggests that the parotid glands play an important role in the balance of nitrate and nitrite levels in both whole saliva and the body.

[Stable expression of human cytochrome P450 2E1 cDNA in nasopharyngeal cancer cell line CNE-2]

OBJECTIVE

This study as designed to investigate the function of CYP2E1 protein in chemical carcinogen metabolism in vitro and its action mechanisms in nasopharyngeal carcinogenesis.

METHODS

DAN recombination technique was used to construct a eukaryotic expression vector pcDNA3.1-2E1 of human cytochrome P450 2E1 cDNA. The vector was introduced into a nasopharyngeal cancer cell line CNE-2 mediating by lipofectamine. After these transforming cells were treated with G418 for 2 weeks, several G418-resistant clones were selected and amplified in culture.

RESULTS

The authors acquired two cell clones CNE2-2E1-1 and CNE2-2E1-2 with stable integration and expression of exogenous CYPE2E1 cDNA. After Southern blot analysis, RT-PCR and Western blot were fulfilled.

CONCLUSION

The cell models setting here will be a good tool in the further study of CYP2E1. At the same time, its use will help to screen chemical carcinogenesis and to elucidate the mechanism of carcinogenesis which is related to chemical carcinogen activated by CYP2E1.

Distribution of nitric oxide synthase in stomach myenteric plexus of rats

AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus.

METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique.

RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus. The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62 ± 38 cells/mm² (antrum), 43 ± 32 cells/mm² (body), and 32 ± 28 cells/mm² (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels.

CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.

Synthesis and characterization of fluorinated metal arsenates with a layer structure: (C4H12N2)(1.5)[M3F5(HAsO4)2(AsO4)] (M = Fe, Ga)

Two fluorinated metal arsenates, (C(4)H(12)N(2))(1.5)[M(3)F(5)(HAsO(4))(2)(AsO(4))] (M = Fe, Ga), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, magnetic susceptibility, Mössbauer spectroscopy, and (71)Ga NMR spectroscopy. The two compounds are isostructural and crystallize in the monoclinic space group P2(1)/c (No. 14) with a = 8.394(1) A, b = 21.992(3) A, c = 10.847(1) A, beta = 96.188(2) degrees, and Z = 4 for the Fe compound, and a = 8.398(1) A, b = 21.730(3) A, c = 10.679(1) A, beta = 95.318(2) degrees, and Z = 4 for the Ga compound. The structure consists of infinite chains of corner-sharing MX(6) (X = O, F) octahedra and dimers of edge-sharing MO(3)F(3) octahedra, which are linked into two-dimensional sheets through arsenate tetrahedra with diprotonated piperazinium cations between the sheets. Magnetic susceptibility and Mössbauer spectroscopy confirm the presence of Fe(III). The (71)Ga MAS NMR spectrum clearly shows a line shape consisting of three components, corresponding to three crystallographically distinct Ga sites.

A miniaturized liquid core waveguide-capillary electrophoresis system with flow injection sample introduction and fluorometric detection using light-emitting diodes

A novel miniaturized capillary electrophoresis (CE) system is described where a Teflon AF-coated silica capillary serves both as the separation channel and as a transversely illuminated liquid core waveguide. This device uniquely uses flow injection (FI)-based split-flow sample introduction through a falling-drop interface. An H-channel structure fixed on a microscope glass slide utilizes a horizontal separation capillary with tubular sidearms on each end that serve as inlet and outlet flow-through electrode reservoirs. The inlet reservoir also functions as a falling-drop interface for coupling to the FI system. A blue LED is used as excitation source. A large-core optical fiber takes the emitted fluorescence to an inexpensive PMT with two layers of green plastic used for optical filtering. No focusing arrangement is needed. Continuous FI introduction of a series of 30-microL samples containing a mixture of of fluorescein isothiocyanate (FITC)-labeled amino acids allowed a throughput rate up to 144 samples/ h, with approximately 2% carryover and good precision (3.2% RSD). Baseline separation was achieved for FITC-labeled arginine, phenylalanine, glycine, and FITC in sodium tetraborate buffer (pH 9.5) with plate heights of 5.4-5.5 microm and plate numbers of 2.34 x 10(4)-2.37 x 10(4) under electrical field strengths of 214 V/cm for injection and 500 V/cm for separation (14-cm capillary, 48-microm i.d.). Detection limits (S/N = 3) were 1.3 microM for arginine and 1.9 microM for phenylalanine and glycine.

Risk factors for cardiovascular mortality and morbidity: the WHO Mutinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine the associations between classic cardiovascular risk factors and diabetes specific factors and the incidence of fatal and non-fatal end-points in a large cohort of diabetic patients.

METHODS

A cohort of 4,743 diabetic patients participating in the WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD) has been followed up for about 12 years and the incidence of fatal and non-fatal cardiovascular disease outcomes assessed.

RESULTS

The importance of blood pressure, serum cholesterol and proteinuria as predictors for cardiovascular disease mortality, fatal and non-fatal myocardial infarction and stroke is confirmed for patients with Type I (insulin-dependent) and Type II (non-insulin-dependent diabetes mellitus. Serum triglyceride was associated with cardiovascular disease death in Type II diabetes and in women with Type I diabetes and with MI incidence in Type II diabetes and stroke in Type II diabetic women. Fasting plasma glucose was associated with cardiovascular disease death, incidence of myocardial infarction and stroke in Type II diabetes only. In Type II diabetes, multivariate analysis confirmed that fasting plasma glucose was related to cardiovascular disease mortality independent of other risk factors. The independent relation of triglyceride to cardiovascular disease death was statistically significant only for Type II diabetic men. The presence of retinopathy was related to cardiovascular disease death and incidence of myocardial infarction in both types of diabetes and to stroke in Type II diabetes.

CONCLUSION/INTERPRETATION

This large cohort study shows that the assessment of cardiovascular disease risk in diabetes must include 'diabetes-related' variables such as glycaemic control, proteinuria and retinopathy, as well as the classic risk factors, blood pressure, smoking and dyslipidaemia. [Diabetologia

Mortality and causes of death in the WHO Multinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine the mortality rates, excess mortality and causes of death in diabetic patients from ten centres throughout the world.

METHODS

A mortality follow-up of 4713 WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD) participants from ten centres was carried out, causes of death were ascertained and age-adjusted mortality rates were calculated by centre, sex and type of diabetes. Excess mortality, compared with the background population, was assessed in terms of standardised mortality ratios (SMRs) for each of the 10 cohorts.

RESULTS

Cardiovascular disease was the most common underlying cause of death, accounting for 44 % of deaths in Type I (insulin-dependent) diabetes mellitus and 52 % of deaths in Type II (non-insulin-dependent) diabetes mellitus. Renal disease accounted for 21% of deaths in Type I diabetes and 11% in Type II diabetes. For Type I diabetes, all-cause mortality rates were highest in Berlin men and Warsaw women, and lowest in London men and Zagreb women. For Type II diabetes, rates were highest in Warsaw men and Oklahoma women and lowest in Tokyo men and women. Age adjusted mortality rates and SMRs were generally higher in patients with Type I diabetes compared with those with Type II diabetes. Men and women in the Tokyo cohort had a very low excess mortality when compared with the background population.

CONCLUSION/INTERPRETATION

This study confirms the importance of cardiovascular disease as the major cause of death in people with both types of diabetes. The low excess mortality in the Japanese cohort could have implications for the possible reduction of the burden of mortality associated with diabetes in other parts of the world.

Risk factors for renal failure: the WHO Mulinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine risk factors for, and differences in, renal failure in diabetic patients from 10 centres.

METHODS

Risk factors for renal failure were examined in 3,558 diabetic patients who did not have renal disease at baseline in the WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD).

RESULTS

In 959 subjects with Type I (insulin-dependent) diabetes mellitus and 2,559 with Type II (non-insulin-dependent) diabetes mellitus, the average follow-up was 8.4 years (+/- 2.7). By the end of the follow-up period 53 patients in the Type I diabetic group and 134 patients in the Type II diabetic group had developed renal failure (incidence rate 6.3:1,000 person years). Increasing age and duration of diabetes were associated with renal failure in Type II and Type I diabetes. In Type II diabetes duration of diabetes was a more important risk factor than age. In both Type I and Type II diabetic retinopathy and proteinuria were strongly associated with renal failure. Systolic blood pressure was associated with renal failure in Type I but not in Type II diabetic patients. ECG abnormalities at baseline, self-reported smoking and cholesterol were not associated with renal failure. Triglycerides were measured in a subset of centres. Among those with Type II, but not Type I diabetes, triglycerides were associated with renal failure independently of systolic blood pressure, proteinuria or retinopathy. In Type II diabetes fasting plasma glucose was associated with renal failure independently of other risk factors.

CONCLUSION/INTERPRETATION

We have confirmed the role of proteinuria and retinopathy as markers of renal failure and the importance of hyperglycaemia in renal failure in Type I and Type II diabetes. Plasma triglycerides seem to be an important predictor of renal failure in Type II diabetes. In Type I diabetes systolic blood pressure is an important predictor of renal failure.

Solid-state trans-cis isomerization of captopril determined by thermal Fourier transform infrared (FT-IR) microspectroscopy

Thermal Fourier transform infrared (FT-IR) microspectroscopy was used to investigate the conformational isomerization of captopril in the solid state. The result indicates that the IR peak intensity of captopril for original bands decreased dramatically at 102 degrees C, but for new bands it increased with the rise of temperature. The frequency of C=O stretching mode for carboxylic acid and for amide was located at a higher wavenumber of 1747 cm(-1) and at a lower frequency of 1591 cm(-1) as compared with the general compound, suggesting the existence of trans isomer of captopril in the solid state by intramolecular hydrogen bonding. Beyond 102 degrees C, several new bands at 1720, 1645, and 1610 cm(-1) were observed with the rise of temperature, indicating the coexistence of a cis isomer. However, the cis isomer could transform gradually to the trans isomer after cooling. The thermodynamics of equilibrium mixture of cis/trans isomers were also studied. The trans isomer was more stable than the cis isomer, but the cis isomer was favored at the higher temperature.

Expression of Ca(2+)/calmodulin-dependent protein kinase IV (caMKIV) messenger RNA during murine embryogenesis

Ca(2+)/calmodulin-dependent protein kinase IV (CaMKIV) is a monomeric, multifunctional serine/threonine protein kinase that is expressed in subanatomic regions of the central and peripheral nervous system, T lymphocytes, and male germ cells. It is frequently localized to the nucleus, where it serves as a mediator of Ca(2+)-dependent gene expression. Although CaMKIV expression in the adult rat central nervous system and thymus has been described, little is known about the embryonic expression of murine CaMKIV. Here we report a thorough embryonic expression study of CaMKIV mRNA from embryonic day 9.5 through postnatal day 1. Expression patterns during embryonic development are significantly different from those of adults, suggesting specific roles for CaMKIV during development. Regions of high CaMKIV mRNA expression include thymic and bone cartilage primordia as well as specific cranial nerve ganglia (trigeminal, vestibulocochlear, and glossopharyngeal), thalamus, and dorsal root ganglia. This pattern of expression is chronologically consistent with periods of extensive cellular differentiation, proliferation, or neuronal survival selection and shows a predilection for neural crest-derived cells. These trends, along with recent studies in the CaMKIV null mouse, suggest that CaMKIV may play an important physiological role in cellular differentiation during embryogenesis.

[Determination of intestinal trefoil factor in burned rats by reversed-phase high performance liquid chromatography]

A reversed-phase high performance liquid chromatographic method was established for determination of intestinal trefoil factor (ITF) in burned rats. The analysis was carried out on a Hypersil C4 column (30 nm, 5 microns, 4.6 mm i.d. x 250 mm) with gradient elution of acetonitrile-trifluoroacetic acid-water solution at a flow rate of 1 mL/min and detected by a UV detector at 214 nm. The volume proportion of trifluoroacetic acid in water is 0.1% and the volume proportion of acetonitrile in mobile phase ranged from 19.5% to 42.0%. The linear range of the method was 1 mg/L-100 mg/L with relative coefficient of 0.9989. The minimum detection limit was 0.5 mg/L. The recovery of ITF added ranged between 93.95% and 105.90%. The intra-day and inter-day RSD of ITF were less than 5.33% and 6.10% respectively. This method is precise, accurate and can be used for the determination of ITF in intestinal mucosal of burned rats. Therefore, it is helpful in the research of comparing the effects of enteral feeding and parenteral nutrition on ITF expression.

Reaction kinetics of solid-state cyclization of enalapril maleate investigated by isothermal FT-IR microscopic system

To investigate the reaction kinetics of the solid-state degradation process of enalapril maleate, a Fourier transform infrared microspectroscope equipped with thermal analyzer (thermal FT-IR microscopic system) was used. The isothermal stability study was conducted at 120-130 degrees C for 1-2 h and changes in the three-dimensional plots of the IR spectra of enalapril maleate with respect to heating time were observed. The study indicates that the bands at 1649, 1728, and 1751 cm(-1) assigned to intact enalapril maleate gradually reduced in peak intensity with heating time. However, the peak intensities at 1672 and 1738 cm(-1) (due to enalapril diketopiperazine (DKP) formation) and at 3250 cm(-1) (corresponding to water formation) gradually increased with heating time. The solid-state diketopiperazine formation and the degradation process of enalapril maleate via intramolecular cyclization were found to be simultaneous. The isothermal decomposition curves were sigmoidal and were characterized by induction and acceleration periods, indicating the presence of autocatalytic solid-state decompositions. Moreover, the power-law equation (n = 1/4) was found to provide the best fit to the kinetics of decomposition. This isothermal FT-IR microscopic system was easily used to investigate the degradation of enalapril maleate and the concomitant formation of DKP. The solid-state reaction of enalapril maleate required an activation energy of 195+/-12 kJ/mol to undergo the processes of decomposition and intramolecular cyclization.

[Development of Triticum aestivum-Haynaldia villosa 6VS ditelosomic substitution line via phlb mutant]

Chinese Spring phlb mutant (C S phlbphlb) was crossed to Triticum aestivum-Haynaldia villosa 6V (6A) alien substitution line and F1 back was crossed with C. S phlbphlb. One LV 02 with varied H. villosa 6V chromosome and one LV 02-01 with 40 T. aestivum chromosome, one H. villosa 6V and 6VS chromosome were screened in BC1F1 and BC1F2 respectively by C-banding and the fluorescence in situ hybridization (FISH). In segregated generation of LV 02-01, eight T. aestivum-H. villosa 6VS ditelosomic substitution lines were screened by FISH and C-banding.

Stereocontrolled synthesis of acyclic 1,3-diols via condensation of tungsten-syn-pi-pentadienyl complexes with aldehydes. A new Prins reaction via s-trans-diene cationic intermediates

In the presence of BF(3).Et(2)O, condensation of CpW(CO)(2)(syn-pi-2-methoxycarbonylpentadienyl) with aldehydes generated tungsten-eta(4)-trans-diene cation in cold toluene, and hydrolysis of this salt afforded tungsten-pi-allyl-anti-1,3-diols in good yields. This new synthesis of anti-1,3-diols represents an atypical Prins reaction that is applicable to normal aldehydes. The anti/syn ratios of 1,3-diols increased with an increase in the size of the aldehydes. These anti-1,3-diols were transformed into various complex oxygen heterocycles based on two demetalations: (1) conversion to an allyl cation followed by nucleophilic attack and (2) condensation with aldehydes via its CpW(NO)Cl derivative, to give functionalized alpha-methylene butyrolactones. A semi-emperical calculation was performed to deduce the transition-state structure to rationalize the anti-stereoselectivity.

[Experimental study of allogenic tendon with sheath grafting in chicken]

OBJECTIVE

To investigate availability of deep freeze stored allogenic tendon with sheath grafting in repairing the tendon and sheath defect in the II area of flexor digitorum tendon.

METHODS

Sixty chickens with tendon and sheath defect were divided into 2 groups randomly, group A was treated with allogenic grafting and group B was treated with autogenic grafting, these two groups were divided into two subgroups respectively, they were, group A1 allogenic tendon with whole sheath grafting, group A2 allogenic tendon with partial sheath grafting, group B1 autogenic tendon with whole sheath grafting and group B2 autogenic tendon with whole sheath grafting. All the allogenic grafts were treated by deep freeze. Histomorphological study, histoimmunological study and slipping function of the grafts were measured after operation.

RESULTS

In group A1 and B1, the local reaction was sever, the nutrition of tendon graft was barricaded by the whole sheath resulting in adhesion, degeneration and necrosis. In group A2 and B2, the tendon graft healed well and little adhesion existed between tendon and sheath. The results showed that there were significant differences between tendon grafting with whole sheath and tendon grafting with partial sheath.

CONCLUSION

Deep freeze store can reduce the immunogenicity of allogenic tendon with sheath. Allogenic tendon with partial sheath grafting can be used as a new biological material for repairing the tendon and sheath defect.

Comparison of comfort and local complications after cardiac catheterization

The purpose of this study was to compare the effects of 4 hours of bed rest versus 6 hours of bed rest on patients' safety, comfort, and satisfaction levels. Using a quasi-experimental design, the authors studied 118 left-heart catheterization patients who were randomly assigned to 4 hours or 6 hours of bed rest. Among the study participants, only 1 in the 6-hour group had significant bleeding. There were no complications in the 4-hour group. There were no statistically significant differences between the two groups on any of the other study variables. Given the lack of significant complications for the 4-hour group and similar comfort levels for both study groups, these findings suggest the feasibility of reducing the standard period of postcatheterization bed rest from 6 hours to 4 hours, thereby possibly lowering the cost of the outpatient procedure.