[Ultrasonic and pathological comparative analysis of different subtypes of breast encapsulated papillary carcinoma].

Objective: To investigate the clinicopathological and ultrasonic characteristics of patients with breast encapsulated papillary carcinoma (EPC) and the comparative analysis of different subtypes. Methods: A total of 57 patients with pathological diagnosis of breast EPC in the First Affiliated Hospital of Nanjing Medical University from September 2014 to August 2020 were retrospectively collected. Based on pathological diagnosis, patients were divided into 3 subtypes, and their clinical, pathological and ultrasonic manifestations were compared and analyzed. Results: Among the enrolled patients, there were 2 males and 55 females, aged 41-88 (63±11) years. The lesion diameter of EPC was 7.0-7.5 (2.9±1.9) cm. There were 16 cases of simple EPC, 9 cases of EPC with ductal carcinoma in situ (DCIS), and 32 cases of EPC with infiltration. The molecular classification was mainly luminal (55/57, 96.6%), of which 38 cases were Luminal A type and 17 cases were Luminal B type. The majority ultrasound images of EPC showed nodules with size greater than 2 cm (68.4%), regular morphology (64.9%), edge finishing (54.4%), no burr forming angles (82.5%), and no calcification (93%). There were differences between different subtypes. The simple EPC was closer to the nipple than the EPC with infiltration, with regular shape and smooth edge (P<0.05). Compared with the EPC with DCIS, the EPC with infiltration had richer blood flow and was farther away from the nipple (P<0.05). There was no significant difference between the simple EPC and the EPC with DCIS (P>0.05). Conclusion: The simple EPC often showed benign signs on ultrasound, such as regular morphology, smooth edge, and cystic-solid internal structure. If the distance between the lesion and the nipple was greater than 3 cm, the shape was irregular, and the edge was blurred, the possibility of EPC with infiltration was high. Multi-modality image fusion was helpful for accurate diagnosis and treatment of EPC.

[The relationship between migration time and the prevalence of myopia of children and adolescents aged 6-18 years old in Shenzhen].

Objective: To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen. Methods: From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin'an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ2 test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results: The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [OR (95%CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [OR (95%CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [OR (95%CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion: The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

[Analysis on epidemic situation and spatiotemporal changes of COVID-19 in Anhui].

We used the epidemic data of COVID-19 published on the official website of the municipal health commissions in Anhui province to map the spatiotemporal changes of confirmed cases, fit the epidemic situation by the population growth curve at different stages and analyze the epidemic situation in Anhui Province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7 with a change from J-shaped curve to S-shaped curve. As the reporting time of cases might be 3-5 days later than the actual onset time, the number of new cases in Anhui province actually began to decline around February 2 to February 4, 2020.

Prevalence of comorbid major depressive disorder in Type 2 diabetes: a meta-analysis of comparative and epidemiological studies.

AIMS: To examine the average point prevalence of major depressive disorder in people with Type 2 diabetes and its associated factors in a comprehensive meta-analysis. METHODS: Two researchers independently conducted a systematic literature search of PubMed, EMBASE, PsycINFO and Cochrane databases. Studies reporting the prevalence of major depressive disorder in people with Type 2 diabetes were identified and analysed using a random-effects model. RESULTS: A total of 26 studies meeting the inclusion criteria were included in the study. The point prevalence of major depressive disorder was 14.5% (95% CI 7.9-25.3; I²=99.65). People with Type 2 diabetes were more likely to have major depressive disorder compared with the general population (odds ratio 1.73, 95% CI 1.38-2.16). Subgroup and meta-regression analyses showed that study site, study type, diagnostic criteria and age significantly moderated the prevalence of major depressive disorder. CONCLUSIONS: In this meta-analysis, the average point prevalence of major depressive disorder in people with Type 2 diabetes was high. Routine screening and more effective interventions should be implemented for this population.

Particle-sounding of the spatial structure of kinetic Alfvén waves.

Kinetic Alfvén waves (KAWs) are ubiquitous throughout the plasma universe. Although they are broadly believed to provide a potential approach for energy exchange between electromagnetic fields and plasma particles, neither the detail nor the efficiency of the interactions has been well-determined yet. The primary difficulty has been the paucity of knowledge of KAWs' spatial structure in observation. Here, we apply a particle-sounding technique to Magnetospheric Multiscale mission data to quantitatively determine the perpendicular wavelength of KAWs from ion gyrophase-distribution observations. Our results show that KAWs' perpendicular wavelength is statistically 2.4[Formula: see text] times proton thermal gyro-radius. This observation yields an upper bound of the energy the majority proton population can reach in coherent interactions with KAWs, that is, roughly 5.76 times proton perpendicular thermal energy. Therefore, the method and results shown here provide a basis for unraveling the effects of KAWs in dissipating energy and accelerating particles in a number of astrophysical systems, e.g., planetary magnetosphere, astrophysical shocks, stellar corona and wind, and the interstellar medium.

Observations of ionospheric electron beams in the plasma sheet.

Electrons streaming along the magnetic field direction are frequently observed in the plasma sheet of Earth's geomagnetic tail. The impact of these field-aligned electrons on the dynamics of the geomagnetic tail is however not well understood. Here we report the first detection of field-aligned electrons with fluxes increasing at ~1 keV forming a "cool" beam just prior to the dissipation of energy in the current sheet. These field-aligned beams at ~15 R(E) in the plasma sheet are nearly identical to those commonly observed at auroral altitudes, suggesting the beams are auroral electrons accelerated upward by electric fields parallel (E([parallel])) to the geomagnetic field. The density of the beams relative to the ambient electron density is δn(b)/n(e)~5-13% and the current carried by the beams is ~10(-8)-10(-7) A m(-2). These beams in high ß plasmas with large density and temperature gradients appear to satisfy the Bohm criteria to initiate current driven instabilities.

Observational evidence of ring current in the magnetosphere of Mercury.

The magnetic gradient and curvature drift of energetic ions can form a longitudinal electric current around a planet known as the ring current, that has been observed in the intrinsic magnetospheres of Earth, Jupiter, and Saturn. However, there is still a lack of observational evidence of ring current in Mercury's magnetosphere, which has a significantly weaker dipole magnetic field. Under such conditions, charged particles are thought to be efficiently lost through magnetopause shadowing and/or directly impact the planetary surface. Here, we present the observational evidence of Mercury's ring current by analysing particle measurements from MErcury Surface, Space Environment, GEochemistry, and Ranging (MESSENGER) spacecraft. The ring current is bifurcated because of the dayside off-equatorial magnetic minima. Test-particle simulation with Mercury's dynamic magnetospheric magnetic field model (KT17 model) validates this morphology. The ring current energy exceeds [Formula: see text] J during active times, indicating that magnetic storms may also occur on Mercury.

Simultaneous macroscale and microscale wave-ion interaction in near-earth space plasmas.

Identifying how energy transfer proceeds from macroscales down to microscales in collisionless plasmas is at the forefront of astrophysics and space physics. It provides information on the evolution of involved plasma systems and the generation of high-energy particles in the universe. Here we report two cross-scale energy-transfer events observed by NASA's Magnetospheric Multiscale spacecraft in Earth's magnetosphere. In these events, hot ions simultaneously undergo interactions with macroscale (~[Formula: see text] km) ultra-low-frequency waves and microscale ([Formula: see text] km) electromagnetic-ion-cyclotron (EMIC) waves. The cross-scale interactions cause energy to directly transfer from macroscales to microscales, and finally dissipate at microscales via EMIC-wave-induced ion energization. The direct measurements of the energy transfer rate in the second event confirm the efficiency of this cross-scale transfer process, whose timescale is estimated to be roughly ten EMIC-wave periods about (1 min). Therefore, these observations experimentally demonstrate that simultaneous macroscale and microscale wave-ion interactions provide an efficient mechanism for cross-scale energy transfer and plasma energization in astrophysical and space plasmas.

[PI3K/Akt signaling pathway mediates the protective effect of endomorphin-1 postconditioning against myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To investigate the role of PI3K/Akt signaling pathway in mediating the protective effect of endomorphin-1 against myocardial ischemia-reperfusion (IR) injury. OBJECTIVE: Fifty SD male rats were randomly divided into sham operation group, myocardial IR group, endomorphin-1 post-treatment group (EM50 group), endomorphin-1+wortmannin (a PI3K/Akt signaling pathway inhibitor) treatment group (EM50+Wort group), and wortmannin treatment group (Wort group). Rat models of myocardial IR injury were established by ligation of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. The heart rate and mean arterial pressure were monitored during the experiment. Plasma levels of LDH, CK-MB, cTnI, IL-6, TNF-α, SOD and MDA were measured after reperfusion. The mRNA expression of Bax and Bcl-2 was detected using RT-PCR, and the expression of apoptosis-related protein cleaved caspase-3, phosphorylated Akt protein and total Akt protein in myocardial tissue was detected using Western blotting. OBJECTIVE: Myocardial IR injury significantly decreased heart rate and blood pressure of the rats in comparison with the sham operation (P < 0.05). Compared with those in the IR group, the rats in EM50 group showed significantly increased heart rate and blood pressure (P < 0.05) with decreased plasma LDH, CK-MB, cTnI, IL-6, TNF-α and MDA levels (P < 0.05), increased SOD activity (P < 0.05), increased expression of p-Akt protein and Bcl-2 mRNA (P < 0.05), and decreased expression of Bax mRNA and cleaved caspase-3 protein (P < 0.05). In EM50+Wort group, the heart rate and blood pressure were significantly lowered (P < 0.05), plasma LDH, CK-MB, cTnI, IL-6, TNF-α and MDA levels increased (P < 0.05), SOD activity decreased (P < 0.05), the expression of p-Akt protein and Bcl-2 mRNA was reduced (P < 0.05), and the expression of Bax mRNA and cleaved caspase-3 protein increased (P < 0.05) as compared with those in EM50 group. OBJECTIVE: EM-1 postconditioning can regulate cardiac myocyte apoptosis and reduce myocardial IR injury in rats. The PI3K/Akt signaling pathway may play a role in mediating the myocardial protective effects of EM-1 postconditioning.

[Sleep status associated with psychological and behavioral problems in adolescents and children].

Objective: To examine whether sleep status and social jet lag are related to the mental health behaviors in children and adolescents, providing a reference for preventing and improving children and adolescents' mental health behaviors. Methods: A large cross-section was conducted in Baoan District, Shenzhen, from April to May 2019. A total of 30 188 adolescents and children in grades 1-12 in 14 schools were included. The growth trajectory and health index questionnaire of primary and secondary school students were designed to evaluate the sleep status. Mental health behavior problems among students were accessed using the parents' and students' versions of the Strengths and Difficulties Questionnaire. After controlling for confounding factors of demographic variables, including gender, age, parental education level, academic performance, learning burden, and noise impact, a multivariate logistic regression model was used for statistical analyses. Results: The sleep duration of four grades students were 90.4％,90.1％, 98.2％, and 98.4％, respectively. 19.9％ did not have a post-lunch nap. 19.6％ had a wake-up delay of more than or equal to 2 h weekend morning. 35.1％ had an inconsistent bedtime and 15.5％ had an inconsistent awakening time. The multivariate logistic regression model showed that compared with 8-9 h, the sleep duration of elementary school juniors at night less than or equal to 7 h, 7-8 h increased the risk of psychological behavior problems. The sleep time more than 9 h was negatively correlated with psychological behavior problems. The sleep duration of elementary school seniors less than or equal to 7 h increased the risk of psychological behavior problems. The sleep duration of middle school and high school students less than or equal to 6 h increased psychological behavior problems. The ORs (95％CI) appeared as 2.53(1.85-3.47), 2.41(1.11-5.25), respectively. The ones with a sleep time more than 9 h also increased the risk, and ORs (95％CI) appeared as 2.37(1.40-4.01), 5.38 (1.79-16.1), respectively. Both the absence of post-lunch nap and the nap time less than 0.5 h were risk factors for psychological behavior problems in primary and middle school students. The nap time over 1-2 h was also a risk factor for high school students' psychological behavior problems. Waking up at irregular times in the morning, going to bed at varying times in the evening, and delaying getting up for more than or equal to 2 h on weekends were all risk factors for psychological and behavioral problems among primary and middle school students. The ORs (95％CI) of psychological behavior problems of elementary school juniors and seniors, middle school and high school students were 2.07 (1.45-2.97), 1.57 (1.09-2.26), 2.66 (2.06-3.44), 2.48 (1.96-3.15), respectively. Conclusions: Sleep duration, no post-lunch sleep, and daily intraindividual variability of sleep is positively associated with poor mental health. Additionally, social jet lag is associated with mental health problems in students. It is noted that delaying sleep within half an hour on the weekends of elementary school juniors is significantly associated with an increase in bad mental behavior.

Effects of porcine epidemic diarrhea virus infection on tight junction protein gene expression and morphology of the intestinal mucosa in pigs.

Tight junction proteins are important for the maintenance and repair of the intestinal mucosal barrier. The present study investigated relationships among tight junction protein gene expression, porcine epidemic diarrhea virus (PEDV) infection, and intestinal mucosal morphology in piglets. We compared the expression of six tight junction proteins (ZO-1, ZO-2, Occludin, Claudin-1, Claudin-4, and Claudin-5) between seven-day-old piglets infected with PEDV and normal piglets, as well as in PEDV-infected porcine intestinal epithelial cells (IPEC-J2). We also evaluated differences in mucosal morphology between PEDV-infected and normal piglets. The expression of six tight junction protein genes was lower in PEDV-infected piglets than in the normal animals. The expression of ZO-1, ZO-2, Occludin, and Claudin-4 in the intestine tissue was significantly lower (p⟨0.05) in PEDV-infected than in normal piglets. The expression of Claudin-5 in the jejunum was significantly lower in PEDV-infected piglets than in the normal animals (p⟨0.01). The expression of Claudin-1 and Claudin-5 genes in the ileum was significantly higher in PEDV-infected piglets than in normal piglets (p⟨0.01). Morphologically, the intestinal mucosa in PEDV-infected piglets exhibited clear pathological changes, including breakage and shedding of intestinal villi. In PEDV-infected IPEC-J2 cells, the mRNA expression of the six tight junction proteins showed a downward trend; in particular, the expression of the Occludin and Claudin-4 genes was significantly lower (p⟨0.01). These data suggest that the expression of these six tight junction proteins, especially Occludin and Claudin-4, plays an important role in maintaining the integrity of the intestinal mucosal barrier and resistance to PEDV infection in piglets.

MMS observations of electron scale magnetic cavity embedded in proton scale magnetic cavity.

Magnetic cavities (sometimes referred to as magnetic holes) at electron kinetic scale are thought to be one of the extremely small intermittent structures formed in magnetized turbulent plasmas, where the turbulence energy cascaded down to electron scale may finally be dissipated and consequently energize the electrons. However, the geometry and formation of these structures remain not definitively resolved. Here we discuss an electron scale magnetic cavity embedded in a proton scale magnetic cavity observed by the MMS spacecraft in the magnetosheath. By applying an innovative particle sounding technique, we directly depict the boundary of the electron scale magnetic cavity and uncover the geometry. We find that this structure is nearly circular with a radius of 10.0 km and its formation is due to the diamagnetic current. Investigation of the electron scale structure is only recently made possible by the high spatial and temporal resolution provided by MMS observations.

[Effect of influenza and 23-valent pneumococcal polysaccharide vaccinations on elderly with chronic obstructive pulmonary diseases: a community-based intervention study].

Objective: To explore the effect of influenza and 23 valent pneumococcal polysaccharide pneumococcal vaccinations on symptom-improvement among elderly with chronic obstructive pulmonary diseases (COPD). Methods: Data was gathered from 4 communities in 3 National Demonstration Areas set for comprehensive prevention and control of chronic non- communicable diseases in Chongqing city and Ningbo city respectively, from November 2013 to October 2014. The communities were selected by cluster sampling and divided into 4 groups: (1) injected influenza vaccines; (2) injected with pneumococcal vaccines; (3) received both of the two vaccines; (4) the control group that without any intervention measures. All the subjects aged from 60 to 75 were selected to fill in demographic information questionnaire and receive (COPD assessment test, CAT) scores twice, before intervention and 1 year after the vaccination. SAS 9.4 software was used to analyze the change of symptoms and CAT scores before and after the intervention program and comparing the improvement on symptoms among the elderly people under study. Results: A total of 1 244 subjects with nearly same baseline conditions after the propensity score matching, were involved in this study. CAT scores appeared as Median=21 (IQR: 17-26) at baseline. The CAT scores appeared as Median=18 (IQR: 14-24), decreasing in all the 3 vaccinated groups, one year after the intervention program (influenza vaccines, matching t test, t=-6.531, P=0.403; pneumococcal vaccines, Wilcoxon test, H=-9 623, P<0.001; combined vaccine vaccines, matching t test, t=-10.803, P<0.001). However, in the control group, no obvious change was observed (Wilcoxon H=1 167, P=0.403). Proportions of impacts at high or very high levels all decreased in the 3 intervention groups, while little change was observed in the control group. Outcomes from the Factorial analysis suggested that influenza vaccination could improve the general conditions and symptoms including cough, chest tightness, dyspnea, physical activities, and stamina. Pneumococcal vaccination appeared more effective on all of symptoms and indicators. Conclusion: Pneumococcal and influenza vaccination seemed helpful for elderly people suffering COPD to improve the general health condition.

Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons.

Van Allen radiation belts are typically two zones of energetic particles encircling the Earth separated by the slot region. How the outer radiation belt electrons are accelerated to relativistic energies remains an unanswered question. Recent studies have presented compelling evidence for the local acceleration by very-low-frequency (VLF) chorus waves. However, there has been a competing theory to the local acceleration, radial diffusion by ultra-low-frequency (ULF) waves, whose importance has not yet been determined definitively. Here we report a unique radiation belt event with intense ULF waves but no detectable VLF chorus waves. Our results demonstrate that the ULF waves moved the inner edge of the outer radiation belt earthward 0.3 Earth radii and enhanced the relativistic electron fluxes by up to one order of magnitude near the slot region within about 10 h, providing strong evidence for the radial diffusion of radiation belt relativistic electrons.

High-throughput genotyping of single nucleotide polymorphisms with rolling circle amplification.

BACKGROUND: Single nucleotide polymorphisms (SNPs) are the foundation of powerful complex trait and pharmacogenomic analyses. The availability of large SNP databases, however, has emphasized a need for inexpensive SNP genotyping methods of commensurate simplicity, robustness, and scalability. We describe a solution-based, microtiter plate method for SNP genotyping of human genomic DNA. The method is based upon allele discrimination by ligation of open circle probes followed by rolling circle amplification of the signal using fluorescent primers. Only the probe with a 3' base complementary to the SNP is circularized by ligation. RESULTS: SNP scoring by ligation was optimized to a 100,000 fold discrimination against probe mismatched to the SNP. The assay was used to genotype 10 SNPs from a set of 192 genomic DNA samples in a high-throughput format. Assay directly from genomic DNA eliminates the need to preamplify the target as done for many other genotyping methods. The sensitivity of the assay was demonstrated by genotyping from 1 ng of genomic DNA. We demonstrate that the assay can detect a single molecule of the circularized probe. CONCLUSIONS: Compatibility with homogeneous formats and the ability to assay small amounts of genomic DNA meets the exacting requirements of automated, high-throughput SNP scoring.

Solar wind entry into the high-latitude terrestrial magnetosphere during geomagnetically quiet times.

An understanding of the transport of solar wind plasma into and throughout the terrestrial magnetosphere is crucial to space science and space weather. For non-active periods, there is little agreement on where and how plasma entry into the magnetosphere might occur. Moreover, behaviour in the high-latitude region behind the magnetospheric cusps, for example, the lobes, is poorly understood, partly because of lack of coverage by previous space missions. Here, using Cluster multi-spacecraft data, we report an unexpected discovery of regions of solar wind entry into the Earth's high-latitude magnetosphere tailward of the cusps. From statistical observational facts and simulation analysis we suggest that these regions are most likely produced by magnetic reconnection at the high-latitude magnetopause, although other processes, such as impulsive penetration, may not be ruled out entirely. We find that the degree of entry can be significant for solar wind transport into the magnetosphere during such quiet times.

Pharmacological properties of galenical preparation. XIV. Body temperature retaining effect of the Chinese traditional medicine, "goshuyu-to" and component crude drugs.

We orally administered Goshuyu-to or Evodia fruit extract and Ginger extract to untreated rats, and found a slight but not significant rise in their body temperature. In rats treated with chlorpromazine, the administration of Goshuyu-to prevented decrease in the body temperature. After administration of each extract of component crude drugs (Evodia fruit, Ginger, Ginseng: Jujube: such an effect was recognized only by Evodia fruit, and other component crude drugs exhibited no body temperature retaining effect in this experiment system. We further studied the effect of Evodia fruit alkaloid hydroxyevodiamine, evodiamine, rutaecarpine and evocarpine used individually and confirmed that the body temperature retaining effect occurred mainly with evodiamine.

High-pressure-assisted reconstitution of recombinant chloroperoxidase.

An expression vector containing a T7 promoter and an OmpA signal sequence followed by the DNA sequence of mature chloroperoxidase from the fungus Caldariomyces fumago has been transformed into Escherichia coli. This construct gave high-level expression of apochloroperoxidase when induced with isopropyl thiogalactopyranoside. The nonglycosylated apoenzyme was secreted into periplasmic space. The recombinant apochloroperoxidase was expressed at a level representing about 2% of the total cellular protein. Before conversion to holoenzyme, the apochloroperoxidase was denatured in 8 M urea and partially purified by DEAE chromatography. Maximum yields of holoenzyme were obtained when the denatured apochloroperoxidase, dissolved in a refolding buffer containing iron protoporphyrin IX, calcium ions, and oxidized glutathione, was subjected to high pressure (207 MPa) at -12 degrees C and then allowed to refold at atmospheric pressure and room temperature. The recombinant holoenzyme was characterized by absorption and CD spectroscopy and tested for halogenation and peroxidation activity. The yield of active holochloroperoxidase was about 5% when high-pressure treatment was used as part of the reconstitution process. In the absence of pressure treatment, holoenzyme was formed at about the 1% level. The holochloroperoxidase preparations which resulted from high-pressure treatment showed, upon return to atmospheric pressure, a considerably higher content of native-like secondary structure compared to the nonpressurized preparations. These experiments show that active recombinant chloroperoxidase molecules can be produced, and prove that glycosylation is not a mandatory requirement for chloroperoxidase refolding.

Messenger RNA translation state: the second dimension of high-throughput expression screening.

Technological advances over the past 10 years have generated powerful tools for parallel analysis of complex biological problems. Among these new technologies, DNA arrays have provided an important experimental approach for identifying changes in the levels of individual mRNA molecules during important cellular transitions. However, cellular behavior is dictated not by mRNA levels, but by the proteins translated from the individual mRNA species. We report a high-throughput method for simultaneously monitoring the translation state and level of individual mRNA species. Messenger RNAs from resting and mitogenically activated fibroblasts were separated, according to degree of ribosome loading, into well-translated and under-translated pools. cDNA probes generated from these fractions were used to interrogate cDNA arrays. Among approximately 1,200 genes analyzed, less than 1% were found to be translationally regulated in response to mitogenic activation, demonstrating the strong selectivity of this regulatory mechanism. This high-throughput approach is shown to be an effective tool for superimposing translation profile on mRNA level for large numbers of genes, as well as for identifying translationally regulated genes for further study.

Overexpression of eIF4E in Saccharomyces cerevisiae causes slow growth and decreased alpha-factor response through alterations in CLN3 expression.

The association of G(1) cyclins and Cdc28/cyclin-dependent protein kinase catalyzes the cell cycle entry (Start) in budding yeast. Activation of Start is presumed to be triggered by a post-transcriptional increase in Cln3 during early G(1). Cells arrested by mating pheromone show a loss of cyclin-dependent protein kinase activity caused by transcriptional shutoff of cyclins and/or inhibition by Far1. We report that overexpression of eIF4E (Cdc33), a rate-limiting translation initiation factor, causes an increase in CLN3 mRNA translation, which results in increased expression of CLN2 and in slow growth and decreased alpha-factor response. This phenotype was abrogated in a Deltacln3 or Deltacln2 background. We isolated the transcription factor MBP1 as a multicopy suppressor of the growth and alpha-factor response defects. Furthermore, elevated MBP1, a transcriptional regulator of cyclins, altered the transcriptional start site in CLN3 mRNA, shifting it 45 nucleotides upstream of the normal. This lengthened 5'-untranslated region likely reduces translation efficiency and down-regulates CLN3 protein synthesis, thereby correcting for the excess translation promoted by elevated Cdc33. In addition, the CLN2 mRNA level returned to normal. We propose that regulation of translation initiation by Cdc33 plays a pivotal role in the activation of Start and cell cycle progression in budding yeast.