snoU6 and 5S RNAs are not reliable miRNA reference genes in neuronal differentiation

Accurate profiling of microRNAs (miRNAs) is an essential step for understanding the functional significance of these small RNAs in both physiological and pathological processes. Quantitative real-time PCR (qPCR) has gained acceptance as a robust and reliable transcriptomic method to profile subtle changes in miRNA levels and requires reference genes for accurate normalization of gene expression. 5S and snoU6 RNAs are commonly used as reference genes in microRNA quantification. It is currently unknown if these small RNAs are stably expressed during neuronal differentiation. Panels of miRNAs have been suggested as alternative reference genes to 5S and snoU6 in various physiological contexts. To test the hypothesis that miRNAs may serve as stable references during neuronal differentiation, the expressions of eight miRNAs, 5S and snoU6 RNAs in five differentiating neuronal cell types were analyzed using qPCR. The stabilities of the expressions were evaluated using two complementary statistical approaches (geNorm and Normfinder). Expressions of 5S and snoU6 RNAs were stable under some but not all conditions of neuronal differentiation and thus are not suitable reference genes. In contrast, a combination of three miRNAs (miR-103, miR-106b and miR-26b) allowed accurate expression normalization across different models of neuronal differentiation.

Creation of nanostructures by interference lithography for modulation of cell behavior

Emerging evidence of the striking differences that can be induced in the behavior of biological cells through topographical modulation of physically and chemically patterned nanostructured surfaces provides a great impetus for developing novel cellular-scale and sub-cellular-scale nanopatterned substrates and for employing them for exciting new applications in life and medical sciences and biotechnology. However, the lack of availability of cost-effective, large-surface-area nanofabricated substrates of appropriate dimensions and features has proved to be a major impediment for research in this area. Here, we demonstrate a simple and cost-effective method based on interference lithography to produce spatially precise and wide-surface-coverage silicon- and polymer-based nanostructures to study how cells react to nanoscale structures or surfaces.

Human Delta1-pyrroline-5-carboxylate synthase: function and regulation

Mammalian Delta(1)-pyrroline-5-carboxylate synthase (P5CS) is a bifunctional ATP- and NAD(P)H-dependent mitochondrial enzyme that catalyzes the coupled phosphorylation and reduction-conversion of L: -glutamate to P5C, a pivotal step in the biosynthesis of L: -proline, L: -ornithine and L: -arginine. Previously, we reported cloning and characterization of two P5CS transcript variants generated by exon sliding that encode two protein isoforms differing only by a two amino acid-insert at the N-terminus of the gamma-glutamyl kinase active site. The short form (P5CS.short) is highly expressed in the gut and is inhibited by ornithine. In contrast, the long form (P5CS.long) is expressed ubiquitously and is insensitive to ornithine. Interestingly, we found that all the established human cell lines we have studied expressed P5CS.long but not P5CS.short. In addition, expression of P5CS.long can be modulated by hormones: downregulation by hydrocortisone and dexamethasone and upregulation by estradiol, for example. Using a quantitative proteomic approach, we showed that P5CS.long is upregulated by p53 in p53-induced apoptosis in DLD-1 colorectal cancer cells. Functional genomic analysis confirmed that there are two p53-binding consensus sequences in the promoter region and in the intron 1 of the human P5CS gene. Interestingly, overexpression of P5CS by adenoviruses harboring P5CS.long or P5CS.short in various cell types has no effect on cell growth or survival. It would be of importance to further investigate the role of P5CS as a p53 downstream effector and how P5CS.short expression is regulated by hormones and factors of alternative splicing in cells isolated from model animals.

Biomineralisation markers during a phase of active growth in Pinctada margaritifera

To search for the biochemical parameters involved in calcium and carbonate transport during crystal formation and biomineralisation in nacreous molluscs, the carbonic anhydrase activity, the levels of calciotropic hormones in hemolymph and in tissues and the circulating concentration of calcium were measured in pearl oysters (Pinctada margaritifera) during a phase of active growth. Activity of carbonic anhydrase in gill tissue increased linearly with age of the animals, while no age variation in activity was noted for the mantle. The circulating level of total calcium increased during the growth of the animals. Calciotropic hormones were radioimmunoassayed in gill, mantle and hemolymph. Only a calcitonin-gene related peptide (CGRP) could be detected and its concentration decreased as a function of growth, both in hemolymph and mantle. No variation in CGRP concentration with age was observed in gill tissue. Our data demonstrate that carbonic anhydrase and a molecule biologically and immunologically related to CGRP are involved during growth of the animals. In addition, this study shows the presence of three main calcium compartments, gill, hemolymph and mantle, involved in the biomineralisation process.

[Effects of pyracantha fortuneana extract on blood coagulation]

OBJECTIVE

To study the effect of the Pyracantha fortuneana extract and its defferent polar fractions on blood coagulation.

METHODS AND RESULTS

The Pyracantha fortuneana extract could noticeably shorten the coagulation time of glass slide in mice (P < 0.05) after oral administration, and also shorten the recalcification time and prothrombin time in vitro (P < 0.01, P < 0.05), while in three polar fractions of the extract, the effects of the chloroform phase that could shorten the coagulation time of glass slide in mice(P < 0.01) after oral administration, and also shorten the recalcification time and prothrombin time in vitro (P < 0.01) are more noticeable than that of the acetic ether phase (P < 0.01, P < 0.05). The petroleum ether phase has no above-mentioned effect (P > 0.05).

CONCLUSION

The Pyracantha fortuneana extract can reduce the blood coagulation. Both the chloroform phase and the acetic ether phase of the extract have activity of blood coagulation, but the petroleum ether phase does not.

[The apolipoprotein E gene polymorphism in children with steroid-resistant idiopathic nephrotic syndrome]

OBJECTIVE

To study apolipoprotein E gene polymorphism in children with steroid- resistant idiopathic nephrotic syndrome (SRINS).

METHODS

Sixty children with SRINS (including 9 children with focalsclerosing glomerulonephritis) were observed in comparison with 80 age-sex-matched healthy children. Seven lipoprote in metabolism parameters including serum total-cholesterol(TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein AI(apoAI), apolipoprotein B (apoB), lipoprotein (a)[Lp (a)] were detected by enzyme method, and single-strand conformation polymorphism(PCR-SSCP) was used to determine the apoE genotypes in the two groups.

RESULTS

Serum TC, TG, HDL-C, LDL-C, apoAI, apoB, Lp(a) in the observation group were significantly higher than those in the healthy controls (P<0.01). After 6 months, the levels of serum TC, TG, LDL-C,apoB,Lp(a) were 81.25%, 78.13%, 84.38%, 87.50% and 78.13% respectively in 32 SRINS cases of the observation group. The apo epsilon 2 allele gene frequence was higher in the observation group than in the controls (11.66% vs 5.00%, P<0.05). The apo apsilon 2 allele gene frequence in the cases of focalsclerosing glomerulonephritis was significantly higher than that in the controls (22.22% vs 5.00%, P<0.01).

CONCLUSION

The above results indicate the obvious and long term abnormalities of serum lipoprotein metabolism in the children with SRINS. The apo apsilon 2 allele gene frequence is higher in the children with SRINS. There are risk factors for atherosclerosis and cardiovascular diseases in the children with SRINS. The antilipemic drugs should be considered in use for the children with SRINS.

Combined effect of dietary calcium and iron on colonic aberrant crypt foci, cell proliferation and apoptosis, and fecal bile acids in 1,2-dimethylhydrazine-treated rats

To investigate the combined effect of Ca and Fe on colon carcinogenesis, cell proliferation, apoptosis and fecal bile acids, male Wistar rats were fed the diet containing 5 g Ca/kg (normal Ca) or 15 g Ca/kg (excessive Ca) with 45 mg Fe/kg (normal Fe) or 500 mg Fe/kg (excessive Fe) for 32 days, and given an injection of 1,2-dimethylhydrazine on day 4. Supplemental Ca reduced colonic aberrant crypt foci (ACF), especially in excess Fe group. Excessive Fe elevated the ACF, especially in the normal Ca diet. When the Ca intake was high, excessive Fe caused no influence on the ACF. Alteration of colonic ACF was associated with those of liver and serum Fe concentration. Also, colonic cell proliferation and concentration of deoxycholic acid (DCA) in fecal water-soluble fraction were reduced by supplementation of dietary Ca, but unaffected by that of dietary Fe. Supplementation of Ca and/or Fe elevated colonic cell apoptosis. The results suggest that dietary Ca markedly suppresses colon ACF in the Fe-overloaded rats through altering Fe status, and that supplemental Ca lowers colonic cell proliferation and fecal DCA in the water-soluble fraction and elevates colonic cell apoptosis irrespective of Fe status.

Regeneration of N, P and Si near the sediment/water interface of lakes from Southwestern China Plateau

Lake water, pore water, and sediments were sampled in both polluted and unpolluted lakes from Southwestern (SW) China Plateau. The results show that although the mechanisms of nutrient regeneration were similar in the polluted and unpolluted lakes, the processes, however, were much stronger in the polluted lakes. Nitrogen regeneration was mainly of organic process. Phosphorus regeneration was essentially controlled by iron redox cycling near sediment/water interface. Nutrient upward fluxes were in the order SiO2 > NH4+ > PO4(3-). This study has significance for further investigating the response of nutrient biogeochemistry to the increasing nutrient levels in aquatic environments.

[Study on direct determination of Ni, Fe in electroplating solution by XRF flow transporting sample]

This paper put forward a method of continuous flow transporting sample which was applied in quantitative analysis of main elements Ni, Fe in electroplating solution with X-ray fluorescence spectrometer. The method adopts a winding shaped plastic tube device which carries liquid sample. It is flexible, simple, and practical. Using the fluid itself flowing, we can mostly eliminate the errors that were caused by changing fluid because of long-time radiation by X-ray. Through accuracy and precision experiments, it was proved that the method is reliable, convenient, and quick. The results can meet completely the requirement of production and scientific research. A new method of analysis electroplating solution has been provided. The field of analysis by X-ray fluorescence spectrometer was opened up.

High fat diet elevates the activity of inducible nitric oxide synthase and 1,2-dimethylhydrazine-induced aberrant crypt foci in colon of rats

Rats were examined for the effect of dietary level of fat (beef tallow or safflower oil) on colonic activity of inducible nitric oxide synthase (iNOS) which has been suggested to be associated with colon carcinogenesis. In experiment 1, feeding high fat diets (20%) for 3 weeks caused higher activity of the iNOS compared to feeding low fat diets (5%). In experiment 2, rats were fed 20% or 5% beef tallow diet for 11 or 32 days, and given an injection of a carcinogen, 1,2-dimethylhydrazine on day 4. The activity of colonic iNOS and the development of colonic aberrant crypt foci were enhanced by high fat diet.

Increased hepatic activity of inducible nitric oxide synthase in rats fed on a high-fat diet

The effects were examined of the dietary level of fat on the activity of inducible nitric oxide synthase (iNOS) in the liver of rats. In experiment 1, rats were fed on a diet containing 5% or 20% beef tallow or safflower oil for 32 d. The animals were given a subcutaneous injection of the carcinogen, 1,2-dimethylhydrazine (DMH), on d 4. The activity of hepatic iNOS was significantly elevated by the high-fat diet, but was unaffected by the dietary source of the fat examined. In experiment 2, rats were fed on a 5% or 20% beef tallow diet for 11 d or 32 d with or without the DMH treatment. Feeding the high-fat diet and DMH treatment caused higher activity of hepatic iNOS. In experiment 3, the high-fat diet elevated hepatic iNOS activity and the amount of its protein in the lipopolysaccharide-treated rats. The results suggest that hepatic NO production is enhanced by a high-fat diet.

[Serum concentration of insulin-like growth factor-I in cord blood]

OBJECTIVE

To evaluate the role of insulin-like growth factor-I (IGF-I) in fetal growth and placental growth.

METHODS

Cord blood IGF-I was determined by radioimmunoassay (RIA) after serum samples were extracted with acid-ethanol. Linear correlation between variables was tested by calculating pearson's correlation coefficient. student's test was used to compare mean values between groups.

RESULTS

In 102 tested samples, the concentration of cord blood serum IGF-I was correlated with the gestational age, the birth weight of neonates and placental weight (r = 0.32, P < 0.001, r = 0.68, P < 0.001, r = 0.75, P < 0.001). The mean serum level of IGF-I in the small-for-gestational-age (SGA) neonates was significantly lower than that in average-for gestational-age (AGA) (t = 4.77, P < 0.001), But the serum concentration of IGF-I in the Large-for-gestational-aga (LGA) neonates was significantly higher than that of AGA neonates (t = 7.97, P < 0.001).

CONCLUSION

Those results suggested that IGF-I is an important regulator for fetal and placental growth and development. It has the key role for macrosomia and IUGR forming.

[Localization and quantitative analysis of insulin-like growth factor-I in placenta of extreme fetus]

OBJECTIVE

To investigate the immunohistochemical localization of insulin-like growth factor-I (IGF-I) in human placenta and to evaluate the role of IGF-I in fetal growth and placental growth.

METHODS

In 72 tested samples, The cellular distribution of IGF-I in human placenta was determined by using immunohistochemistry. The relative area and mean absorbance were determined by using image analysis technique. Student's t-test was used to compare mean values between groups.

RESULTS

IGF-I immunostaining was found in syncytiotrophoblast, cytotrophoblast and Hoffbauer's cells of chorionic villi and chorion of fetal membranes. The strongest immunoreactivity was observed in the syncytiotrophoblast and cytotrophoblast. The relative area and absorbance in placenta of SGA group were significantly lower than those of AGA group respectively (t = 4.65, P < 0.001; t = 2.15, P < 0.05). But the relative arca and absorbance of LGA were significantly higher than those of AGA (t = 8.72, P < 0.001; t = 7.82, P < 0.001).

CONCLUSION

These results suggested that IGF-I in human placenta was principally synthsized and secreted by syncytiotrophoblast, cytotrophoblast, hoffbauer's cells of chorionic villi and chorion of fetal membranes. IGF-I is an improtant regulator of fetal and placental growth and development. It has the key role for macrosomia and IUGR forming.

Study on the transmission threshold value of bancroftian filariasis

OBJECTIVE

To elucidate the transmission dynamic and epidemic trend of bancroftian filariasis occurred under the condition with no control measure taken 5 years after elimination of filariasis.

METHODS

A 10-year longitudinal observation (from 1984 to 1994) was made in Huayuan Village in Shengli Township of Tancheng County, which used to be a high bancroftian filariasis-endemic area in southern part of Shandong Province.

RESULTS

The microfilarial rate decreased from 0.56% before the study to 0.12% after the study and 8 out of the 9 previous microfilaria-positive cases became negative gradually. During the study period, 6 new microfilaremia cases were detected, 5 of which became negative naturally within 3 to 4 years. Eighty-eight point eight nine per cent of the detected patients with microfilaremia converted into IgG4-negative after 10 years. The natural infective rate of vectors decreased year by year and became zero by the tenth year of the study, the annual transmission potency decreased also from 3.47 to zero by the tenth year.

CONCLUSIONS

It showed that under the local natural environment the biting rate representing the vector density which was obtained by capture method was from 24.1 to 52.5 person/night among the residents who did not use mosquito nets, and 13.5 to 21 person/night among the residents who used mosquito nets. The microfilarial rate of 0.56% in population with the average microfilarial density of 6.6 to 20.7 capita/60 microliters ear blood of residual microfilaria-positive patients might be considered as the terminal threshold of transmission.

[Transposition of the pedicled gluteus maximum myocutaneous flap for the repair of huge sacral pressure sores]

From 1986 to 1992, the authors repaired huge sacral pressure sores in 14 cases using the pedicled gluteus maximum myocutaneous flap. The treatment was completed in one stage and the results were satisfactory in all the cases during the follow-up period of 6 months to 7 years. No recurrence occurred. The authors concluded that the method is a good treatment for persistent sacral pressure sores.

Pericardiocentesis and drainage by a silicon rubber line without echocardiographic guidance. Experience in 55 consecutive patients

Pericardiocentesis and drainage with a silicon rubber line were performed safely in 55 patients via the subxiphoid (80 times) or apical (1 time) approach at the bedside without echocardiographic guidance. The subxiphoid approach, which is close to the posterior of the sternum or the costal cartilage with a small acute-angle (15-30 degrees) to the parietal pericardium in front of the right ventricle, can avoid injuring the heart, liver and lungs. A line with sideholes near the distal end, which provides convenient drainage and has better histocompatibility, can be kept in place for a long period of time (1-82 days). It was also convenient to inject air, drugs or fluid through the line. There were no procedure-related serious complications or deaths. Emergency drainage with the Seldinger technique, especially for small to moderate effusions, is safe and simple.

[Electron spin resonance (ESR) study on hair of rats with diabetic cataract]

The hair taken from 40 rats with diabetic cataract and 20 normal controls was tested by using ESR. It was found that the 'g factor' of the hair of the rats with diabetic cataract is higher than that in normal controls. The intensity of ESR signals of the hair taken from rats with diabetic cataract is three times higher than that of ESR signals of the hair from the normal controls. The results have suggested a good reappearance and a remarkable increase in number of the free radicals and other particles of paramagnetic substances during the course of the development of the rats' diabetic cataract. The study provides new scientific data for the theory of free radicals damaging to the crystal in the process of the formation of diabetic cataract.