Roles of DWI and T2-weighted MRI volumetry in the evaluation of lymph node metastasis and lymphovascular invasion of stage IB-IIA cervical cancer.

AIM: To determine whether magnetic resonance imaging volumetry on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) could be used to assess lymph node metastases (LNM) and lymphovascular invasion (LVSI) in resectable cervical cancer. MATERIAL AND METHODS: Sixty-five consecutive patients with cervical cancer were enrolled retrospectively. Tumour size, including maximum transverse diameter, tumour length, and gross tumour volume (GTV), was evaluated on DWI and T2WI. Apparent diffusion coefficient (ADC) values were measured. Univariate, multivariate, and receiver operating characteristic (ROC) curve analyses were performed to determine whether tumour size and ADC could be used to assess LNM and LVSI. RESULTS: Tumour length on both T2WI and DWI, and T2WI-based and DWI-based GTVs could be used to assess LNM (p=0.002, 0.004, 0.001, and <0.001, respectively). Tumour length on T2WI, T2WI-based GTV, DWI-based GTV, and ADC value could be used assess LVSI (p=0.039, 0.038, 0.012, 0.039, respectively). Multivariate analyses showed both T2WI-based GTV (odds ratio [OR] = 1.044; p=0.008) and DWI-based GTV (OR=1.941; p=0.019) were independent risk factors for LNM. T2WI-based GTV (OR=1.023, p=0.038) and DWI-based GTV (OR=3.275, p=0.008) were independent risk factors for LVSI. No statistically significant difference was identified between the area under the ROC curve (AUC) of the DWI-based GTV and the T2WI-based GTV (0.790 versus 0.775, p=0.113), or the tumour length on both T2WI (0.790 versus 0.734, p=0.185) and DWI (0.790 versus 0.737, p=0.333) for LNM. For LVSI, the AUC of DWI-based GTV was higher than T2WI-based GTV (0.720 versus 0.682, p=0.006). CONCLUSION: GTV on both T2WI and DWI could be used assess LNM and LVSI. DWI-based GTV might show the greatest potential for assessing LNM and LVSI in resectable cervical cancer.

Occupational metal exposures, smoking and risk of diabetes and prediabetes.

BACKGROUND: Metal exposure and tobacco smoking have been independently associated with diabetes, but no study has been conducted to investigate the interaction between them on the risk of diabetes. AIMS: To investigate the effect of occupational exposure to metals, and potential effect modification by smoking, on the risk of diabetes and prediabetes in a cohort of Chinese male workers. METHODS: We assessed metal exposure and tobacco smoking at baseline in the Jinchang Cohort of male workers. We used Poisson regression analyses to estimate the interaction between smoking and metal exposures based on occupations, which we grouped according to the measured urinary metal levels. RESULTS: Among the 26008 study subjects, compared with non-smokers, the adjusted prevalence ratio (PR) for diabetes was 1.8 [95% confidence interval (CI) 1.3-2.4] for smokers of >40 pack-years. The adjusted PRs were 1.2 (95% CI 1.1-1.4) among mining/production workers and 2.7 (95% CI 2.4-3.0) among smelting/refining workers, both compared with office workers. There was significant effect modification under the additive model between smoking and metal exposure on the prevalence of diabetes (Pinteraction = 0.001), with an adjusted PR of 3.6 (95% CI 2.4-5.4) for those with >40 pack-years of smoking who had the highest metal exposures, whereas no significant interaction was observed for prediabetes. CONCLUSIONS: Both exposure to metals and heavy smoking were associated with an increased prevalence of diabetes in this large cohort of male workers. There was also strong interaction between these two exposures in affecting diabetes risk that should be confirmed in future studies.

Genetic variations in the UTR of genes related to molting in Eriocheir sinensis.

Crab grows by periodic molting, which is controlled by molt-inhibiting hormone (MIH) and ecdysteroids. Untranslated regions (UTRs) play crucial roles in the posttranscriptional regulation of gene expression. In this study, using crab collected from Changjiang (Yangtze), Huanghe (Yellow), Liaohe, and Yalujiang rivers, 33 haplotypes of the 3ꞌ-UTR of ecdysteroid-regulated protein (ERP) gene were identified, of which 14 haplotypes were observed in more than one individual. One hundred and forty clones of haplotype h2 (41.5%) were observed in samples from all the 4 rivers. Three haplotypes were observed to be insertions. For the whole crab sample, we found a positive Tajima's D value and a negative Fu's Fs test (Tajima's D value = 0.98726; Fu's Fs test = -27.382), although the P values were not significant (P > 0.10). The network profile of these 33 haplotypes presented a single core pattern with h2 as the core. In this study, we found that the UTR of ERP gene had a considerably high genetic polymorphism among crab from regions south to north of China. Furthermore, we observed a relatively high genetic divergence among different haplotypes, which would suggest a high diversity of the crab gene pool.

Identification and association of single-nucleotide polymorphisms in gonadotropin-inhibitory hormone (GnIH) gene with egg production traits in Erlang mountainous chickens.

Gonadotropin-inhibitory hormone (GnIH) gene is an important gene in reproduction. In this study, we screened single-nucleotide polymorphisms (SNPs) in the chicken GnIH gene among 204 individuals in Erlang mountainous chickens. We then analyzed the associations between polymorphisms of the GnIH gene and 5 egg production traits in chickens. Five SNPs (T3305C, T3310C, G3403C, G3411A, and T3591C) were detected. Associations between polymorphic loci and age at first egg, body weight at first egg, weight at first egg, egg weight in 300 days, and egg production in 300 days were analyzed using analysis of covariance. The results showed that SNP1, SNP3, and SNP4 had large effects on age at first egg, while SNP5 had a large effect on body weight at first egg; of the effect of the TT genotype was significantly higher than that of CT (P < 0.01). Further analysis show that the highest frequency (0.2353) haplotype H1H1 was associated with the latest age at first egg. The H4H5 haplotype had a positive effect on egg production in 300 days and a negative effect on weight at first egg. We observed no association between the H3H3 haplotype and body weight at first egg.

Controlling condensate collapse and expansion with an optical Feshbach resonance.

We demonstrate control of the collapse and expansion of an (88)Sr Bose-Einstein condensate using an optical Feshbach resonance near the (1)S(0)-(3)P(1) intercombination transition at 689 nm. Significant changes in dynamics are caused by modifications of scattering length by up to ± 10a(bg), where the background scattering length of (88)Sr is a(bg) = -2a(0) (1a(0) = 0.053 nm). Changes in scattering length are monitored through changes in the size of the condensate after a time-of-flight measurement. Because the background scattering length is close to zero, blue detuning of the optical Feshbach resonance laser with respect to a photoassociative resonance leads to increased interaction energy and a faster condensate expansion, whereas red detuning triggers a collapse of the condensate. The results are modeled with the time-dependent nonlinear Gross-Pitaevskii equation.

Role of serum- and glucocorticoid-inducible kinase-1 in regulating torsion-induced apoptosis in rats.

Serum- and glucocorticoid-inducible kinase-1 (SGK1) is a serine/threonine protein kinase that responds to various stimuli and mediates cell survival. Although it is known that testicular torsion leads to testicular damage and male infertility, the role of SGK1 in torsion remains unclear. This study investigated whether torsion-induced apoptosis is associated with changes in phosphoinositide-dependent protein kinase-1 (PDK1), SGK1 and forkhead transcription factor FOXO3a expression and/or phosphorylation in rats. Sprague-Dawley rats were divided into four groups: sham (control), 1, 2 and 4 h of unilateral torsion. Bilateral testes, testicular interstitial fluid (TIF) and blood samples were collected immediately after torsion. Our results revealed that SGK1 protein and mRNA were abundantly present in testes and were induced by 2 h of torsion, but that phosphorylation of SGK1, PDK1 and FOXO3a decreased simultaneously. After 2 h of torsion, the testosterone secretion capacity of the primary Leydig cells and testicular interstitial cells (TICs) was impaired and apoptotic spermatogonia and TICs were observed; in addition, the mean seminiferous tubular diameter was decreased. Torsion increased plasma corticosterone levels, but decreased plasma luteinizing hormone and testosterone levels. However, the testosterone levels of the TIF in the ipsilateral testes were significantly enhanced after 2 h of torsion, but suppressed in the contralateral testes. This animal study suggests that PDK1, SGK1 and FOXO3a are involved in torsion-induced apoptosis and that medical therapy should be performed as early as 2 h after the occurrence of torsion to prevent further damage.

Active Volcanism Revealed from a Seismicity Conduit in the Long-resting Tatun Volcano Group of Northern Taiwan.

Abundant earthquakes clustered within a particular zone often reflect an active geological feature, such as clustering seismicity along a fault zone and a huge number of volcanic-earthquakes around the erupting conduit. Herein we perform a double-difference tomographic inversion and relocate the seismicity at the long-resting Tatun volcano group (TVG) in northern Taiwan. A dramatic improvement of the earthquake location model surprisingly show that, from 2014 to 2017, two clustered seismic zones are identified in the TVG. One major group of events (>1000) persistently clustered within a ~500 m diameter vertical conduit with a ~2 km height. The clustering seismicity conduit is just located nearby Dayoukeng, one of the strongest fumaroles in the TVG, and is connected to a fracture zone characterized by low Vp/Vs in the shallow crust. The other group of events is clustered within a sphere-like zone beneath Mt. Chihsin around the depths between 0.5 km and 2 km. Both seismic zones are probably triggered by the significantly volcanic gases and fluids ascending from the deep magma reservoir. Combined with a variety of results from literature, the seismicity conduit near the strong fumarole is the evidence for an active volcano and also identifies a likely pathway for ascending magma if the TVG erupts again in the future. But possibility of developing different magma pathways at other clustered seismic zones such as beneath Mt. Chihsin may not be totally excluded.

Motor neuron degeneration in mice that express a human Cu,Zn superoxide dismutase mutation.

Mutations of human Cu,Zn superoxide dismutase (SOD) are found in about 20 percent of patients with familial amyotrophic lateral sclerosis (ALS). Expression of high levels of human SOD containing a substitution of glycine to alanine at position 93--a change that has little effect on enzyme activity--caused motor neuron disease in transgenic mice. The mice became paralyzed in one or more limbs as a result of motor neuron loss from the spinal cord and died by 5 to 6 months of age. The results show that dominant, gain-of-function mutations in SOD contribute to the pathogenesis of familial ALS.

[An assessment of the sublingual immunotherapy with Dermatophagoides farinae on asthma control level and pulmonary function of allergic asthma and rhinitis in adult patient].

Objective:To evaluate the efficacy, asthma control level and pulmonary function of sublingual immunotherapy on allergic asthma and rhinitis in adult patient. Method:This retrospective analysis of 182 cases of adult patient from 18-60 years with allergic asthma and rhinitis, according to the patients' wishes they were divided into drug group（66 patients） and SLIT group（116 patients）. Drug group patients were treated with low to moderate doses of inhaled corticosteroids+long-acting ß2 receptor agonists and mometasone furoate nasal spray+desloratadine tablets as symptomatic treatment. SLIT group was treated by SLIT with Dermatophagoides farina drops on this basis. Before treatment and 1 year, 2 year and 3 years after treatment, the ACT, PEF%, DASS, NASS, TNSS and TMS were evaluated. Result:The ACT, PEF%, DASS, NASS, TNSS and TMS had continuously improved significantly 1 year, 2 year and 3 years after treatment in both groups comparing with baseline（P<0.05）. Compared with 1 year after treatment, SLIT group had lower ACT, PEF%, DASS, NASS, TNSS and TMS in 2 years after treatment（all P<0.05）, whereas drug group had lower TMS and DASS（all P<0.05）. In 3 years of treatment, only SLIT group resulted in significant continuous improvement in DASS and TMS（all P<0.05）. After 1 year, 2 and 3 years of treatment, SLIT group resulted in significantly better ACT, PEF%, DASS, NASS and TMS than drug group（all P<0.05）. After 2 and 3 years of treatment, TNSS of SLIT group were significantly lower than in drug group（P<0.05）. Conclusion:Sublingual immunotherapy for 3 yearswith Dermatophagoides farinae dropsin adult patient with allergic asthma and rhinitis was more effective than drug therapy alone, and asthma control and lung function improved significantly.

[Association between fatty liver and type 2 diabetes in the baseline population of Jinchang Cohort].

Objective: To explore the association between fatty liver and type 2 diabetes mellitus (T2DM) in the baseline-population of Jinchang cohort study. Methods: Data from all the participants involved in the baseline-population of Jinchang cohort study was used, to compare the risks of T2DM in fatty liver and non fatty liver groups and to explore the interaction between family history or fatty liver of diabetes and the prevalence of T2DM. Results: Among all the 46 861 participants, 10 574 were diagnosed as having fatty liver (22.56%), with the standardized rate as 20.66%. Another 3 818 participants were diagnosed as having T2DM (8.15%) with standardized rate as 6.90%. The prevalence of T2DM increased in parallel with the increase of age (trend χ(2)=2 833.671, trend P<0.001). The prevalence of T2DM in the fatty liver group was significantly higher than that in the non-fatty liver group, both in men or women and in the overall population. Compared with the group of non-fatty liver, the risks of T2DM in fatty liver group were seen 1.78 times higher in males, 2.33 times in women and 2.10 times in the overall population, after adjustment for factors as age, levels of education, smoking, drinking, physical exercise, BMI, family history of diabetes and some metabolic indicators (pressure, TC, TG, uric acid, ALT, AST, gamma-glutamyl transferase). Date from the interaction model showed that fatty liver and family history of diabetes present a positive additive interaction on T2DM (RERI=1.18, 95%CI: 0.59-1.78; AP=0.24, 95%CI: 0.14-0.34; S=1.43, 95%CI: 1.21-1.69). Conclusions: Fatty liver could significantly increase the risk of T2DM and a positive additive interaction was also observed between fatty liver and family history of diabetes on T2DM. It was important to strengthen the prevention program on T2DM, in order to effectively control the development of fatty liver.

[Risk factors of gout in Jinchang cohort: a Cox regression analysis].

Objective: To explore the incidence and risk factors of gout in Jinchang cohort and provide scientific evidence for the prevention and control of gout. Methods: People without gout detected by baseline survey in Jinchang cohort were selected as study subjects. All the subjects were followed up through questionnaire interview, physical examination as well as laboratory test from January 24, 2013 to November 24, 2015. Cox regression model was used to analyze the risk factors for gout in Jinchang cohort. In addition, log-linear model was used to analyze the interaction between risk factors. Results: A total of 33 153 subjects were followed up, and there were 277 newly diagnosed gout cases in the cohort. The overall incidence of gout was 0.8%. The incidence of gout in males was higher than that in the females, but the incidence of gout in males and females was similar after the age of 60 years. Cox regression analysis showed that age >40 years (at age 40 to 59 years: HR=2.982, 95%CI: 1.503-5.981; at age 60 to 91 years: HR=2.588, 95%CI: 1.107-6.049), alcohol abuse (HR=2.234, 95% CI: 1.128-4.427), obesity (HR=2.204, 95% CI: 1.216-3.997), diabetes (HR=2.725, 95% CI: 1.500-4.950) and high uric acid (HR=5.963, 95%CI: 3.577-9.943) were risk factors for gout, while weekly beans intake ≥0.25 kg (HR=0.528, 95%CI: 0.345-0.808) and regular physical exercise (HR=0.499, 95% CI: 0.286-0.869) were protective factors for gout. The analysis with log-linear model showed that there were two order effects between the risk factors. Conclusions: Age, beans intake, alcohol abuse, physical exercises, obesity, diabetes and high uric acid were important factors influencing the incidence of gout. It is important to have healthy lifestyle and dietary habits, receive regular health examination to prevent and control the incidence of gout in this cohort.

[The role of PACAP protein in chronic sinusitis with or without nasal polyps].

Objective:To investigate the expression of PACAP protein in chronic rhinosinusitis without/with nasal polyps and refractory chronic rhinosinusitis.Method: Fifty-three patients with nasal polyps,70 cases with chronic sinusitis, 28 patients with refractory chronic rhinosinusitis and 20 control cases were enrolled for this study. The expression of PACAP protein was detected by immunochemistry.Result: ①PACAP protein were expressed in nasal epithelium，glandular epithelium and goblet cells；②The positive intensity of PACAP was" +", " +++", "－-+",and " ++" in nasal polyps, chronic rhinosinusitis, refractory chronic rhinosinusitis, and control group, respectively.Conclusion:PACAP protein mainly locates in nasal epithelium，glandular epithelium and goblet cells. Reduced expression of PACAP may be related with onset of chronic rhiniosinusitis without/with nasal polyps.

Divergent roles of protein kinase C in luteinizing hormone biosynthesis versus release in rat anterior pituitary cells.

We previously demonstrated that protein kinase C (PKC) activators, i.e. L-alpha-1,2-dioctanoyl glycerol (C8) and phorbol 12-myristate 13-acetate (PMA), mimic the stimulatory effects of GnRH on both LH glycosylation and release. To further evaluate the roles of PKC, we determined: 1) the interaction between PKC activator and GnRH; and 2) the effects of depleting cellular PKC with a high dose of PMA on LH glycosylation vs. release. Anterior pituitaries excised from ovariectomized rats were enzymatically dispersed and cultured. In series 1 experiments, day 3 monolayer cells were incubated in the presence of radiolabeled precursors and GnRH (0, 1, or 100 nM), with or without C8 (200 microM). In series 2 experiments, day 2 cells were pretreated with either PMA (1 microM) or vehicle (0.08% dimethyl sulfoxide) for 24 h and then incubated with diluent, GnRH (1 nM), or PMA (20 nM), and radiolabeled precursors for 4 h. LH translation and glycosylation were monitored by measuring incorporation of [14C]alanine ([14C]A) and [3H]glucosamine ([3H]GA), respectively, into LH. Immunoreactive LH (IRLH) was measured by RIA. In series 1 experiments, C8 increased basal release of IRLH, potentiated IRLH release stimulated by 1 nM GnRH, but not by 100 nM GnRH. C8 elevated total [3H]GA-LH but had no additive effects with GnRH. In series 2 experiments, PMA pretreatment inhibited subsequent PMA-stimulated IRLH release. However, PMA pretreatment did not affect GnRH-induced IRLH release even though PMA pretreatment decreased cellular IRLH content. In comparison, PMA pretreatment reduced both GnRH- and PMA-stimulated total [3H]GA-LH. PMA pretreatment had no effects on total [14C]A-LH in the presence of GnRH or PMA, but reduced the basal level. In summary, PKC activators had no additive effects on either IRLH release or LH glycosylation stimulated by a maximal dose of GnRH. However, PMA pretreatment decreased GnRH-induced LH glycosylation without depressing LH release. These results suggest differential roles of PKC in the actions of GnRH on LH glycosylation vs. LH release.

Unimpaired postreceptor regulation of luteinizing hormone secretion by gonadotropin-releasing hormone and estrogen in aged rat anterior pituitary cells.

Delayed, attenuated, or absence of the proestrous LH surge occurs in aging rats. To assess how aging affects the positive feedback action of 17 beta-estradiol (E2) on the pituitary, we determined the responsiveness of rat pituitary cells to GnRH and the secretagogues affecting intracellular signal transduction mechanisms in the presence or absence of E2. We also correlated the LH response to pituitary LH content. Anterior pituitaries excised from ovariectomized Sprague-Dawley rats, either young (3-4 months) or old (19-20 months), were enzymatically dispersed and then pretreated with or without E2 (0.6 nM) for 48 h, followed by incubation for 3 h with or without various secretagogues. The secretagogues included GnRH (1 and 10 nM), veratridine (increases Ca2+ influx; 5 and 10 microM), and phorbol 12-myristate 13-acetate (a protein kinase-C activator; 10 and 100 nM). LH in media and cells were measured by RIA and expressed on the basis of cellular DNA. GnRH, veratridine, and phorbol 12-myristate 13-acetate at all doses stimulated (P < 0.01) LH release in cells from both young and old rats. E2 stimulated (P < 0.05 to P < 0.01) all secretagogue-induced LH release in cells from both young and old rats, but only basal LH release (P < 0.05) in cells from young rats. The magnitude of both basal and secretagogue-induced LH release in either the presence or absence of E2 was smaller (P < 0.01) in cells from old than in those from young rats. The initial cellular LH was lower (P < 0.01) in cells from old than in those from young rats. The LH-releasing ability (expressed as a percentage of total cellular LH) of cells from old rats was identical (P > 0.05) to that of cells from young rats under all conditions studied. These results suggest that the reduced magnitude of LH release by cells from old rats may be attributed to reduced cellular LH, rather than to impaired estrogen feedback or impaired signal transduction mechanisms. It remains to be determined whether LH biosynthesis per cell and/or the number of gonadotropes decrease with age.

Differential effect of age on transforming growth factor-beta 1 inhibition of prolactin gene expression versus secretion in rat anterior pituitary cells.

Transforming growth factor-beta 1 (TGF-beta 1) synthesized in the pituitary may act as an autocrine/paracrine regulator of lactotrope function. We examined the effects of TGF-beta 1 on PRL messenger RNA (mRNA), PRL synthesis, and PRL secretion in cultured anterior pituitary (AP) cells from rats at different ages. APs excised from ovariectomized female Sprague-Dawley rats, either young(2-3 months old; average serum PRL: 9 ng/ml), middle-aged (11-12 months old; average serum PRL: 133 ng/ml), or old (24 months old; average serum PRL: 159 ng/ml), were dispersed and cultured for 5 days. Then, cells were washed and challenged with increasing doses of TGF-beta 1 (0-100 ng/ml) for 1-48 h in serum-free medium. Northern blot analysis showed an increase in basal PRL mRNA levels, and a decrease in responsiveness to TGF-beta 1 with age. TGF-beta 1 suppressed PRL mRNA in a dose- and time-dependent manner in cells from young rats. Maximum inhibition was observed at 0.5-1 ng/ml of TGF-beta 1. At 0.5 ng/ml TGF-beta 1, significant reduction in PRL mRNA was detected at 6 h, and maximum inhibition was observed at 12-48 h post TGF-beta 1 incubation. Cells from middle-aged rats were less responsive to TGF-beta 1, whereas cells from old rats did not seem to respond under our experimental conditions. In addition to its effect on PRL mRNA in young AP cells, TGF-beta 1 dose dependently inhibited the rate of PRL synthesis, as indicated by reduced [35S]methionine incorporation into immunoprecipitated PRL. Responsiveness of PRL synthesis to TGF-beta 1 inhibition also decreased with age; however, significant inhibition by TGF-beta 1 on PRL synthesis could still be observed in old AP cells. Analysis by RIA demonstrated that young AP cells produced lower levels (15 micrograms/10(6) cells.24 h) of PRL in culture medium than old AP cells (32 micrograms/10(6) cells.24 h). TGF-beta 1 decreased medium PRL levels in old AP cells as efficaciously as in young AP cells. Significant reduction in medium PRL secreted by young AP cells was observed at 3 h when changes in both PRL mRNA and PRL synthesis were not evident. Taken together, our data suggest that TGF-beta 1 affects PRL production at multiple levels. Moreover, its inhibition on PRL synthesis and mRNA expression, but not on PRL secretion, is age-related. Thus, TGF-beta 1 may play an important role in regulating lactotrope function during aging.

Glucocorticoid-inducible expression of a glutamine synthetase-CAT-encoding fusion plasmid after transfection of intact chicken retinal explant cultures.

In this communication we demonstrate that gene transfer methodology can be applied to study gene expression in intact retinal explant cultures. The appropriate enzyme activity is observed in extracts obtained after electroporation of embryonic day-10 chicken retina with plasmids containing the chloramphenicol acetyltransferase-encoding or beta-galactosidase-encoding reporter genes under transcriptional control by the Rous sarcoma virus long terminal repeat. Similar results are obtained using Ca.phosphate-mediated gene transfer. Moreover, it has been previously established that glucocorticoid hormones stimulate transcription of glutamine synthetase (Glns) mRNA in embryonic retina. We report here that, based on the results of gene transfer experiments with chimeric plasmids containing 5'-flanking DNA derived from the cloned chicken Glns-encoding gene (Glns), essential glucocorticoid response elements reside between approx. 1.3 kb and 2.5 kb upstream from the Glns transcription start point. These data show that transfection of explant cultures can provide a useful approach to the study of gene expression in complex systems.

The structure of the chicken glutamine synthetase-encoding gene.

Complementary DNA (cDNA) and genomic clones encoding chicken glutamine synthetase (Glns) have been isolated. The nucleotide (nt) sequence of the 2728-bp cDNA specifies a 91-nt 5' untranslated sequence, a 1119-nt open reading frame, and a 1518-nt 3' untranslated sequence that contains several A + T-rich regions but lacks a canonical endonucleolytic-cleavage/polyadenylation signal. Based on sequence analysis of the cloned gene, the Glns transcription unit spans 7.0 kb and contains seven exons.

Protein expression both in mammalian cell lines and in yeast Pichia pastoris using a single expression plasmid.

We have designed and constructed a novel expression vector capable of producing recombinant proteins in both mammalian cell lines and the yeast strain Pichia pastoris. In this vector, a yeast promoter is placed inside an intron of the mammalian transcription unit. A yeast transcription termination sequence is placed immediately downstream of the mammalian polyadenylation site. In mammalian cells, transcription is driven by a mammalian promoter. The yeast promoter within the intron is removed by RNA processing. However, protein expression in yeast cells can be achieved utilizing the yeast promoter immediately upstream of the 3' splice site and the target genes. Our data indicate that this vector can express beta-galactosidase efficiently in both mammalian cell lines and the yeast strain P. pastoris.

Gastric inhibitory polypeptide and gastric acid secretion in pregnant rats.

The effects of pregnancy on the basal and pentagastrin-stimulated gastric acid secretion and the level of plasma gastric inhibitory polypeptide (GIP) in rats were studied on pentobarbital-anaesthetized non-pregnant rats and rats in the 1st, 2nd, or 3rd week of gestation. Acid output was determined by titration of the gastric perfusate. Basal secretion was collected for 45 min before a 30 min infusion of pentagastrin (8 micrograms/ml/300 g body weight). Concentration of plasma GIP was measured by a radioimmunoassay (RIA). The immunoreactivity of GIP-like substance in the extract of the rat placenta collected from the rat at day 21 of gestation was examined by RIA. The biological activity of GIP-like substance in the rat placenta extract was tested by the reduction of pentagastrin-stimulated gastric acid secretion in male rats. The basal level of gastric secretion was higher in late pregnancy as compared with the non-pregnant rats. Pentagastrin induced a greater increase of gastric acid secretion in early but not late pregnant rats as compared with the non-pregnant animals. The basal and post-pentagastrin level of plasma GIP was higher in rats in late pregnancy. Both immunoreactivity and biological activity of GIP exist in the rat placenta extract. These results suggest that the normalization of gastric acid secretion in late pregnant rats is at least in part due to the production of GIP-like substance from placenta.

Studies of two-species Bose-Einstein condesation.

We describe our recent progress on the investigation of two-species Bose-Einstein condensation. From a theoretical analysis we show that there is a new rich phenomenology associated with two-species Bose-Einstein condensates which does not exist in a single-species condensate. We then describe results of a numerical model of the evaporative cooling process of a trapped two-species gas.