The gene encoding human nuclear protein tyrosine phosphatase, PRL-1. Cloning, chromosomal localization, and identification of an intron enhancer

Expression of the rat PRL-1 gene, which encodes a unique nuclear protein tyrosine phosphatase, is positively associated with cellular growth during liver development, regeneration, and oncogenesis but with differentiation in intestine and other tissues. Here, we analyzed the structure of the human PRL-1 gene and localized it to chromosome 6 within band q12. Human, rat, and mouse PRL-1 are 100% conserved at the amino acid level and 55% identical to a newly identified Caenorhabditis elegans PRL-1. The presence of two promoter activities, P1 and P2, in the human PRL-1 gene were identified by primer extension and RNase protection assays. A functional TATA box was identified in promoter P1 upstream of the non-coding first exon. A non-canonical internal promoter, P2, was found in the first intron that results in PRL-1 transcripts beginning 8 base pairs downstream of the 5'-end of exon 2 and causes no alteration in the encoded protein. The first 200-base pair region of either promoter P1 or P2 conferred high basal transcriptional activity. An enhancer that bound a developmentally regulated factor, PRL-1 intron enhancer complex (PIEC), was localized to the first intron of the human PRL-1 gene. The presence of PIEC correlated with the ability of the intron enhancer to confer transcriptional activation in HepG2 and F9 cells. The intron enhancer contributed significantly to PRL-1 promoter activity in HepG2 cells which contain PIEC but not to NIH 3T3 cells which do not.

[Clinical study on reduction of postpartum bleeding in cesarean section by misoprostol]

OBJECTIVE

To observe the effects of misoprostol on reduction of postpartum bleeding in cesarcan section.

METHODS

One hundred and eighty-two cesarean sections were randomized into three groups: misoprostol group (n = 60), 600 micrograms misoprostol was given orally when peritoneum was incised; misoprostol and oxytocin group (n = 64), 600 micrograms misoprostol was given orally and 20 IU oxytocin was injected into uterine muscle immediately after delivery of baby. Oxytocin group (n = 58), 20 IU oxytocin was injected into uterine muscle and 20 IU intravenous injection immediately after delivery of baby. The amount of bleeding within 2 hours after delivery was measured.

RESULTS

The mean amount of bleeding in misoprostol group was 212 +/- 56.0 ml, in misoprostol and oxytocin group was 208 +/- 55.4 ml, oxytocin group was 345 +/- 64.7 ml, respectively. The difference was significant P < 0.01 between misoprostol group and oxytocin group, there was no differences between misoprostol group and misoprostol plus oxytocin group.

CONCLUSION

Misoprostol is more effective in reduction of postpartum bleeding than that of oxytocin.

[Preliminary study on radiant spectra of the leaves of paddy and upland rice]

The characteristics of the radiant spectra (i.e. absorption, reflectance and transmission) of leaves of paddy and upland rice were studied. The experiment proves that the characteristics of the radiant spectra of the seedling leaves of paddy and upland rice is basically the same in the range of 200-800nm, and their chlorophyll content of the leaves is also quite near (the average values for paddy and upland rice are 4.25mg/g and 4.28mg/g, respectively). However, the absorption of the flag leaves of upland rice is higher and the transmission is lower compared to paddy rice in the heading-flowering period, while the reflectance is almost the same except for 550nm. The chlorophyll content in the leaves of upland rice is approximate twice as that of paddy rice (the average values of paddy and upland rice are 0.86mg/g and 1.86mg/g, respectively).

[Energy metabolism of men in full pressure suit with additional pressure]

The energy metabolism of men in full pressure suit with additional pressure and without additional pressure were measured during rest and exercise. Results show that the rates of energy metabolism of men in full pressure suit with additional 28 kPa pressure and without additional pressure increased as the exercise load increased. The rates of energy metabolism of men in full pressure suit with additional 28kPa pressure had no significant difference during rest and 0.9W exercise, but significantly increased during 8.5 W exercise, as compared with that without additional pressure. It suggested that full pressure suit with 28 kPa did not affect human energy metabolism during rest, but affected during exercise.

A generalized F mixture model for cure rate estimation

Cure rate estimation is an important issue in clinical trials for diseases such as lymphoma and breast cancer and mixture models are the main statistical methods. In the last decade, mixture models under different distributions, such as exponential, Weibull, log-normal and Gompertz, have been discussed and used. However, these models involve stronger distributional assumptions than is desirable and inferences may not be robust to departures from these assumptions. In this paper, a mixture model is proposed using the generalized F distribution family. Although this family is seldom used because of computational difficulties, it has the advantage of being very flexible and including many commonly used distributions as special cases. The generalised F mixture model can relax the usual stronger distributional assumptions and allow the analyst to uncover structure in the data that might otherwise have been missed. This is illustrated by fitting the model to data from large-scale clinical trials with long follow-up of lymphoma patients. Computational problems with the model and model selection methods are discussed. Comparison of maximum likelihood estimates with those obtained from mixture models under other distributions are included.

BRCA1 physically associates with p53 and stimulates its transcriptional activity

Mutations of the BRCA1 tumor suppressor gene are the most commonly detected alterations in familial breast and ovarian cancer. Although BRCA1 is required for normal mouse development, the molecular basis for its tumor suppressive function remains poorly understood. We show here that BRCA1 increases p53-dependent transcription from the p21WAF1/CIP1 and bax promoters. We also show that BRCA1 and p53 proteins interact both in vitro and in vivo. The interacting regions map, in vitro, to aa 224-500 of BRCA1 and the C-terminal domain of p53. Tumor-derived transactivation-deficient BRCA1 mutants are defective in co-activation of p53-dependent transcription and a truncation mutant of BRCA1 that retains the p53-interacting region acts as a dominant inhibitor of p53-dependent transcription. BRCA1 and p53 cooperatively induce apoptosis of cancer cells. The results indicate that BRCA1 and p53 may coordinately regulate gene expression in their role as tumor suppressors.

Effect of electrode size on impedance images of two- and three-dimensional objects

The sensitivity of an impedance imaging system to small cylindrical inhomogeneities in two-dimensional (2-D) and three-dimensional (3-D) saline tanks was studied for different height electrodes and different height targets. Experimental results were compared with analytical models. Inhomogeneities in the 3-D tank having limited vertical extent were detected by electrodes of vertical size comparable to that of the inhomogeneity. Taller electrodes had increased sensitivity to short targets to only a limited extent. When the electrode height was more than twice that of the target, sensitivity decreased or remained the same with further increases in electrode height. The system was less sensitive to inhomogeneities in the 3-D tank than to those in the 2-D tank. The distinguishability of conductors was greater than that of insulators in the 3-D tank, and the opposite was true in the 2-D tank, consistent with an analytical result.

[Quantitative analysis of vestibulo-ocular reflex and optokinetic reflex electronystagmography in patients with unilateral loss of vestibular function]

OBJECTIVE

To study changes of the vestibular function in the process of vestibular compensation.

METHODS

The electronystagmography recording of spontaneous nystagmus(SN) with tests for vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) were performed in 105 patients with unilateral loss of vestibular function, the results were analysed quantitatively.

RESULTS

(1) Twenty-one patients with courses from 3 days to 6 years presented a SN directed towards the intact side, with an average slow phase velocity (ASPV) of 7.12-12.07 degrees/s. (2) The intensity of VOR nystagmus as a response to the warm-cold water stimulation to the intact ear was lower than that of normal subjects. (3) By 0.167 Hz, 90 degrees sinusional oscillation stimulation, the ASPVs of the patients' VOR nystagmus directed towards the intact and affected sides were lower than that of the normal. A predominance of VOR nystagmus rotation towards the intact side was found in patients with courses < or = 5 years. There was no predominance of VOR nystagmus found in patients with courses > 5 years. (4) There was no significant difference between the optokinetic nystagmus (OKN) intensity of the normal persons and that of patients with lesions outside the cerebellopontine angle and with tumors in cerebellopontine angle which was < 2.5 cm in diameter. The OKN intensity of patients with tumors in cerebellopotine angle with diameters > or = 2.5 cm was lower than that of normal subjects. A predominance of OKN towards the intactside was found in these patients.

CONCLUSION

The vestibular function is in inhibitory and the vestibular system becomes rebalanced due to this inhibition in the process of vestibular compensation.

[Effects of hypoxia and qigong on urine malondialdehyde, superoxide dismutase and circulating endothelial cell in humans during simulated weightlessness]

Changes of lipid hyperoxidation and amount of circulating endothelial cells under simulated weightlessness and factors that may influence these changes were observed in 3 groups of subjects (5 in each group) exposed to 17d - 6 degrees head down bed rest (HDBR), HD-BR+ hypoxia and HDBR + qigong respectively. The results showed: (1) simple HDBR promotes antioxidation activity and attenuates hyperoxidation of lipids, and hypoxia and have some influence on the former but not on the latter; (2) circulating endothelial cells decreased significantly after simple HDBR for 7 d but recovered to normal when HDBR continued for 17 d. Hypoxia showed no influence on this effect while Qigong alleviated it significantly. It suggests that (1)both hypoxia and Qigong have some influence on the promotion of antioxidation activity but have no influence on the production of oxygen free radicals. (2) Qigong shows some antagonistic effect against the attenuation of circulating endothelial cells by HDBR.

Negative regulation of yeast telomerase activity through an interaction with an upstream region of the DNA primer

A number of published studies indicate that telomerase may interact with oligonucleotide primers in a bipartite manner, with the 3'-end of the primer positioned at the catalytic site of the enzyme and a more 5' region of the primer binding to a second or 'anchor' site of the enzyme. We systematically investigated the effects of mutations in the DNA primer on overall binding and polymerization by yeast telomerase. Our studies indicate that there is sequence-specific interaction between telomerase and a substantial region of the DNA primer. Mutations in the 3'-most positions of the primer reduced polymerization, yet had little effect on overall binding affinity. In contrast, mutations around the -20 position reduced binding affinity but had no effect on polymerization. Most strikingly, mutations centered around the -12 position of the DNA primer reduced overall binding affinity but dramatically enhanced primer extension, as well as primer cleavage. This finding suggests that reduced interaction with the -12 region of the DNA primer can facilitate a step in the catalytic region of yeast telomerase that leads to greater polymerization. A tripartite model of interaction between primer and telomerase is proposed to account for the distinct effects of mutations in different regions of the DNA primer.

[Detection of rotavirus RNA using DIG labelled probe prepared by polymerase chain reaction]

The digoxigenin (DIG) labelled cDNA probe of rotavirus was directly prepared by polymerase chain reaction (PCR). The results of cDNA-RNA hybridization showed that the DIG-cDNA probe exhibits rotavirus specificity and can detect as tiny as 10 pg rotavirus RNA. 120 fecal samples of diarrhea from infants and young children were tested by dot-blot hybridization. It was shown that the positive rate of dot-blot hybridization(65.0%) was significantly higher than that of PAGE(49.1%). This study indicated that direct preparation of DIG-labelled rotavirus-cDNA probe by PCR is much faster and simpler than common method of labeling.

[Immunodiagnosis of cysticercosis by simplified western blotting using recombinant fusion protein as antigen]

AIM

To provide simple and useful method for the immunodiagnosis of cysticercosis.

METHODS

Fusion protein of beta-galactosidase-Cysticercus cellulosae cDNA was analysed with simplified Western blot.

RESULTS

The positive rate was 93.5% when detecting 124 cases of human cysticercosis sera with four clones (cC1, cC2, cP1 and cH1) and 100% when detecting 38 cases of porcine cysticercosis sera with three clones (cC1, cC2 and cP1), being higher than those using monoclone fusion protein alone. Moreover, the fusion proteins did not react with other parasitosis sera.

CONCLUSION

Simplified Western blot analysis using recombinant fusion protein as antigen was highly sensitive and specific and easy to be operated.

Computational models for the formation of protocell structures

There have been various attempts to simulate the self-assembly process of lipid aggregates by computers. However, due to the computationally complex nature of the problem, previous simulations were often conducted with unrealistic simplifications of the molecules' morphology, intermolecular interactions, and the environment in which the lipid molecules interact. In this article, we present a new computational model in which each lipid is simulated by a more realistic amphiphilic particle consisting of a hydrophilic head and a long hydrophobic tail. The intermolecular interactions are approximated by a set of simple forces reflecting physical and chemical properties of lipids, for example, hydrophobicity and electrostatic forces, which are believed to be crucial for the formation of various aggregates. With a set of carefully selected parameters, this model is able to simulate successfully the formation of micelles in an aqueous environment and reversed micelle structures in an oil solvent from an initially randomly distributed set of lipidlike particles. This model can be used to study, at the microscopic level, the self-assembly of different protocell structures in the evolutionary process and the impact of environmental conditions on the formation of these structures. It may be further generalized to simulate the formation of other, more complex structures of amphiphilic molecules such as monolayer and bilayer aggregates.

[Human lens epithelial cells culture in vitro]

PURPOSE

To provide a simple and rapid procedure to culture human len epithelial cells in vitro.

METHODS

Specimens of capsule lentils were isolated from lens by microscissors. They were cut into small segments and then directly implanted into basks(culture bottles). The tissue pieces were cultured in a incubation at 37 degrees C with PR1640 until attached cells reached confluence. The len epithelium were passaged by tropism.

RESULTS

Len epithelial cells usually appeared after 4 days in incubation. The cells growed rapidly in a way of attachments.

CONCLUSION

Len epithelial cells were easily cultured with our method. The procedure is simple, rapid and highly successful.

Biotransformation of compactin to pravastatin by Actinomadura sp. 2966

Actinomadura sp. strain 2966 can effectively convert compactin to pravastatin. The degree of conversion observed was 65% to 78% of compactin added and 65% to 88% of compactin taken up, depending on the concentration of compactin and duration of the experiment. Increasing the compactin concentration resulted in a higher final pravastatin concentration especially when compactin was added intermittently. Higher glucose concentrations had no effect on the bioconversion although uptake of compactin was inhibited. The conversion was linear over 16 hours. The system requires no induction and thus appears to be different from previously studied hydroxylases from actinomycetes.

Identification and characterization of a telomerase activity from Schizosaccharomyces pombe

A telomerase-like primer extension activity has been detected in chromatographic fractions derived from Schizosaccharomyces pombe extracts. This primer extension activity acts preferentially on dG-rich oligodeoxynucleotides, is sensitive to RNase A pretreatment and requires all four deoxynucleotides for optimal polymerization. The extension products are also truncated by the inclusion of any one of the four dideoxynucleotides, consistent with the presence of all four bases in the S.pombe telomeric repeats. The intensity distribution of the extension products and the dideoxynucleotide termination pattern suggest that nucleotide addition is template directed, and that telomere-like sequences are added to the primers. In particular, the sequence d(CGGTTA), a variant of the S.pombe telomeric repeat, can be added directly by the in vitro activity. Partially purified S.pombe telomerase sediments as a 35S particle, suggesting that it exists in vivo as part of a large multi-protein complex.

Optical resolution of DL-alanine by using immobilized Aspergillus oryzae cells

Mycelium pellets with diameters of 1-2 mm and containing abundant aminoacylase were obtained by the liquid fermentation of Aspergillus oryzae 3042. By the cross-linking method with reagents of gelatin and formaldehyde, the immobilized A. oryzae cells (IAC) were prepared with much higher activity and reactive properties. The effects of factors on enzymatic activity of IAC were investigated. When substrate concentration was less than 0.15 mol/L, the Michaelis-Menten mechanism was suitable for this reaction.

[Evaluating clinical significance of tumor necrosis factor-alpha and hydroxyproline in blood of patients with active pulmonary tuberculosis]

OBJECTIVE

To evaluate the clinical significance of tumor necrosis factor-alpha (TNF-alpha) and hydroxyproline (HYP) in blood of patients with active pulmonary tuberculosis (APT).

METHOD

Contents of TNF-alpha and HYP in blood of 28 patients with APT and 17 normal subjects were determined with enzyme-linked immunosorbent assay and ultraviolet spectrophotometer respectively.

RESULT

It was found that the concentrations of TNF-alpha and HYP in patients with APT before antituberculosis treatment were obviously higher than those of the normal subjects (192.85 +/- 37.14 ng/L vs 89.36 +/- 23.18 ng/L and 4.96 +/- 1.13 mg/L vs 1.64 +/- 0.33 mg/L respectively, all P < 0.001) and those who received 3- month anti-tuberculosis treatment (192.65 +/- 37.14 ng/L vs 112.50 +/- 44.93 ng/L and 4.96 +/- 1.13 mg/L vs 2.17 +/- 0.39 mg/L respectively, all P < 0.001). TNF-alpha level was significantly correlated with HYP (r = 0.5132, P < 0.001).

CONCLUSION

The results indicate that TNF-alpha might play an important role in inducing pulmonary tissue damage of APT, and the lowering of HYP content in blood might indicate that pulmonary tuberculosis is recovering from active stage.

Arrest of the cell cycle by the tumour-suppressor BRCA1 requires the CDK-inhibitor p21WAF1/CiP1

Much of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in the BRCA1 tumour-suppressor gene. The nuclear protein BRCA1 has the properties of a transcription factor, and can interact with the recombination and repair protein RAD51. Young women with germline alterations in BRCA1 develop breast cancer at rates 100-fold higher than the general population, and BRCA1-null mice die before day 8 of development. However, the mechanisms of BRCA1-mediated growth regulation and tumour suppression remain unknown. Here we show that BRCA1 transactivates expression of the cyclin-dependent kinase inhibitor p21WAF1/CIP1 in a p53-independent manner, and that BRCA1 inhibits cell-cycle progression into the S-phase following its transfection into human cancer cells. BRCA1 does not inhibit S-phase progression in p21-/- cells, unlike p21+/+ cells, and tumour-associated, transactivation-deficient mutants of BRCA1 are defective in both transactivation of p21 and cell-cycle inhibition. These data suggest that one mechanism by which BRCA1 contributes to cell-cycle arrest and growth suppression is through the induction of p21.

Immunohistochemical localization of lysosomal cathepsin D in schwannomas

The immunohistochemical localization of cathepsin D (CD) was demonstrated for the first time in 54 schwannomas (32 intra- and 22 extracranial; 47 benign and 7 malignant) and 5 normal nerve fibers. Granular or vesicular CD-reactive structures were observed in all normal Schwann cells. All tumors contained CD-reactive tumor cells, although the population of CD-reactive tumor cells, the density, intracellular localization, and morphology of CD-reactive structures, and the intensity of CD immunoreactivity varied from case to case, portion to portion, and cell to cell, differing variously from those in normal Schwann cells. The variations were greater in malignant than in benign schwannomas. In mildly degenerate tumor cells, CD immunoreactivity was increased, possibly in response to the increased intracellular degenerate proteins, suggesting that the mechanism of induction of lysosomal proteases preserved in normal cells is not affected by the process of neoplastic transformation. In lesions of severe degeneration or necrosis, CD immunoreactivity was lost in most tumor cells but was strong in macrophages invading the lesions and perivascular regions. CD immunoreactivity was observed at various intensities in tumor cells in the Antoni type A area but not in most tumor cells in the Antoni type B area, suggesting that Antoni type B lesions show degenerative changes. The presence of CD-reactive tumor cells in all tumors examined and strong CD immunoreactivity observed at the invasion front of tumors in some cases of benign or malignant schwannoma suggests the possible role of CD in tumor invasion in some cases.

Cyclopia in one of discordant twins: a case report

Cyclopia is an uncommon congenital anomaly resulting from arrest of the development of the anterior end of the neural plate. It is always associated with abnormalities of the brain. Cyclopia has never been reported in one twin only. In this report, we describe a case of cyclopia in a female infant with normal karyotype who was one of discordant twins. The infant died perinatally. The parents were healthy and not sanguineously related. Prenatal imaging studies revealed cyclopia, holoprosencephaly and hypognathia. Postmortem examinations revealed one orbit, one eyeball and absence of the nose. The central nervous system included rudimentary cerebral hemispheres with fusion of the two lateral ventricles and the third ventricle forming a single large cavity. The superior aspect of each cerebral hemisphere consisted of only a transparent membrane. The olfactory bulb nad tract was absent. The optic nerves were not identified.

[Analysis of chromosome karyotype of Lycium chinense Mill]

The chromosome karyotypes of wild Lycium chinese and its cultivated breeds for vegetable have been studied. The Chromosome 12 of both has a satellite. The former, with 24 chromosomes and 1B karyotype, is a diploid and its karyotype formula is 2n = 2x = 24 = 18m + 6sm. The chromosome number of the latter is 48. As a tetrploid, it has 2B karyotype and a karyotype formula 2n = 4x = 48 = 36m + 12sm.

Cloning, human chromosomal assignment, and adipose and hepatic expression of the CL-6/INSIG1 gene

Rat CL-6 is the most highly insulin-induced gene in a liver cell line and is expressed in proliferating liver during regeneration and development. CL-6 is now denoted INSIG1 (insulin-induced gene 1). Human INSIG1 was isolated and found to be 80% identical to the rat gene within the translated region. It was located on human chromosome 7 within band q36. The human INSIG1 promoter conferred a high level of expression in both liver and fibroblast cell lines. INSIG1 expression was upregulated at the transcriptional level in rat regenerating liver and induced in a model of murine adipocyte differentiation, suggesting that INSIG1 may play a role in growth and differentiation of tissues involved in metabolic control.

HRS/SRp40-mediated inclusion of the fibronectin EIIIB exon, a possible cause of increased EIIIB expression in proliferating liver

Serine-arginine (SR)-rich proteins are believed to be important in mediating alternative pre-mRNA splicing. HRS/SRp40 expression is elevated in liver cell proliferation during development, regeneration, and oncogenesis. We tested whether HRS expression correlates with the appearance of alternatively spliced fibronectin transcripts during liver growth. HRS was highly expressed during the proliferative phase of liver development, correlating with expression of the fibronectin EIIIB alternative exon. In regenerating liver, HRS protein was induced in a time course consistent with the observed increase in fibronectin transcripts containing the EIIIB exon, particularly in nonparenchymal liver cells. Furthermore, in an in vivo assay, HRS, and not other SR proteins, directly mediated EIIIB exon inclusion in the fibronectin transcript. This alternative splicing was dependent on a purine-rich region within the EIIIB exon to which HRS specifically bound. We have established that HRS has the potential to contribute to the regulation of fibronectin pre-mRNA splicing during liver growth. Changes in fibronectin forms may be important in modifying liver architecture during the proliferative response, thus providing a potential mechanism by which SR proteins may participate in cellular growth control.