The jigsaw puzzle of pedigree: whole-genome resequencing reveals genetic diversity and ancestral lineage in Sunong black pigs

The Sunong black pig is a new composite breed under development generated from Chinese indigenous pig breeds (i.e., Taihu and Huai) and intensive pig breeds (i.e., Landrace and Berkshire), which is an important genetic material for studying breeding mechanisms. However, there is currently limited knowledge about the genetic structure and germplasm characteristics of Sunong black pigs. To comprehensively understand their genetic composition and ancestry proportions, we performed population structure and local ancestry inference analysis based on whole-genome sequencing information. The results showed that Sunong black pigs could be clustered independently into a group, whose pedigree was intermediate between indigenous and commercial pig breeds, but closer to commercial pigs. Furthermore, local ancestry inference analysis revealed that Sunong black pigs inherited immune and reproductive traits from indigenous pig breeds, including CC and CXC chemokine family, Toll-like receptor family, IFN gene family, ESR1, AREG and EREG gene, while growth and development-related traits were inherited from commercial pig breeds, including IGF1 and GSY2 gene. Overall, Sunong black pigs have formed a relatively stable genome structure with some advantageous traits inherited from their ancestral breeds. This study deepened the understanding of the breeding mechanism of Sunong black pigs and provided a reference for cross-breeding programmes in livestock.

[Expert consensus on the biobank development of oral genetic diseases and rare diseases and storage codes of related biological samples from craniofacial and oral region]

The biological samples of oral genetic diseases and rare diseases are extremely precious. Collecting and preserving these biological samples are helpful to elucidate the mechanisms and improve the level of diagnose and treatment of oral genetic diseases and rare diseases. The standardized construction of biobanks for oral genetic diseases and rare diseases is important for achieving these goals. At present, there is very little information on the construction of these biobanks, and the standards or suggestions for the classification and coding of biological samples from oral and maxillofacial sources, and this is not conducive to the standardization and information construction of biobanks for special oral diseases. This consensus summarizes the background, necessity, principles, and key points of constructing the biobank for oral genetic diseases and rare diseases. On the base of the group standard "Classification and Coding for Human Biomaterial" (GB/T 39768-2021) issued by the National Technical Committee for Standardization of Biological Samples, we suggest 76 new coding numbers for different of biological samples from oral and maxillofacial sources. We hope the consensus may promote the standardization, and smartization on the biobank construction as well as the overall research level of oral genetic diseases and rare diseases in China.

[Prickle planar cell polarity protein 1 involved in the pathogenesis of skeletal class Ⅲ malocclusion]

Objective: To explore the mechanisms of prickle planar cell polarity protein 1 (PRICKLE1) involved in the occurrence of skeletal Class Ⅲ malocclusion. Methods: After extracting the genomic DNA of all family members of the skeletal Class Ⅲ malocclusion pedigree with maxillary hypoplasia collected in the Department of Orthodontics at the Affiliated Stomatological Hospital of Nanjing Medical University in October 2021, whole exome sequencing and Sanger sequencing were performed to screen pathogenic genes/mutation sites and validate the mutations. Jaw tissue was collected during the operation of orthognathic patients who were treated in the Department of Oral and Maxillofacial Surgery at the same hospital from October 2021 to December 2022. Following the extraction of human jaw bone marrow mesenchymal stem cells and transfection with overexpressing lentivirus (lentiviruses overexpressing the gene of interest served as the wild group, lentiviruses overexpressing mutation site served as the mutant group) and knockdown lentivirus (divided into knockdown group 1 and 2, with transfection interference negative lentiviruses as the control group). Various assays including real-time fluorescence quantitative PCR (RT-qPCR), Western blotting, proliferation and Transwell assays, alkaline phosphatase staining and alizarin red staining were performed. Construction of zebrafish animal model, morpholino oligonucleotide (MO) were injected to knock down the expression of prickle1a and prickle1b in zebrafish (co-knocking group), and the control group was injected with standardized MO as a reference. Transcriptome sequencing, enrichment analysis and co-expression analysis were performed on the zebrafish craniofacial tissues of the two groups. Results: Two patients of this family carried this mutation PRICKLE1 c.113C>T. The transfection experiments showed that compared with the wild group (relative expression of PRICKLE1 was 21.97±0.60), the relative expression of mutant group (5.05±0.05) was significantly reduced (P<0.05), and cell proliferation and migration ability significantly enhanced (P<0.05), and osteogenic differentiation ability was significantly reduced (P<0.05). Compared with the control group, the proliferation and migration ability of cells in the two knockdown groups were significantly enhanced (P<0.05), and the osteogenic differentiation ability was significantly reduced (P<0.05). Zebrafish model experiments showed the width of the ethmoid plate was significantly reduced in the co-knocking group (282.50±61.77, t=5.29, P<0.001) compared with the control group (338.80±24.92). Transcriptome data and enrichment analysis showed that the differentially expressed genes were significantly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway after the simultaneous knockdown of prickle1a and prickle1b in zebrafish. Conclusions: PRICKLE1 c.113C>T mutation might suppress the osteoblastic differentiation ability of jaw bone marrow mesenchymal stem cells by downregulating the MAPK signaling pathway, thereby involving the development of skeletal Class Ⅲ malocclusion.

Genome-wide scans for selection signatures in indigenous pigs revealed candidate genes relating to heat tolerance

Heat stress is a major problem that constrains pig productivity. Understanding and identifying adaptation to heat stress has been the focus of recent studies, and the identification of genome-wide selection signatures can provide insights into the mechanisms of environmental adaptation. Here, we generated whole-genome re-sequencing data from six Chinese indigenous pig populations to identify genomic regions with selection signatures related to heat tolerance using multiple methods: three methods for intra-population analyses (Integrated Haplotype Score, Runs of Homozygosity and Nucleotide diversity Analysis) and three methods for inter-population analyses (Fixation index (F_ST), Cross-population Composite Likelihood Ratio and Cross-population Extended Haplotype Homozygosity). In total, 1 966 796 single nucleotide polymorphisms were identified in this study. Genetic structure analyses and F_ST indicated differentiation among these breeds. Based on information on the location environment, the six breeds were divided into heat and cold groups. By combining two or more approaches for selection signatures, outlier signals in overlapping regions were identified as candidate selection regions. A total of 163 candidate genes were identified, of which, 29 were associated with heat stress injury and anti-inflammatory effects. These candidate genes were further associated with 78 Gene Ontology functional terms and 30 Kyoto Encyclopedia of Genes and Genomes pathways in enrichment analysis (P < 0.05). Some of these have clear relevance to heat resistance, such as the AMPK signalling pathway and the mTOR signalling pathway. The results improve our understanding of the selection mechanisms responsible for heat resistance in pigs and provide new insights of introgression in heat adaptation.

[Influence factors of poor efficacy after flap repair operation in patients with pressure ulcers]

Objective: To investigate the influence factors of poor efficacy after flap repair operation in patients with pressure ulcers. Methods: The retrospective case series study was conducted. From January 2011 to June 2021, 125 patients with stage Ⅲ and Ⅳ pressure ulcers treated in Hainan General Hospital met the inclusion criteria. There were 82 males and 43 females, aged 15-90 (57±20) years. According to the postoperative effects, the patients were divided into poor efficacy group (47 cases) and good efficacy group (78 cases). The clinical data of patients in the two groups were collected, including the age, gender, location, stage, size, and bone exposure of pressure ulcers, preoperative microorganism culture results of wound exudate sample, whether combined with osteomyelitis, diabetes, lower limb paroxysmal myospasm, and gatism or not, the number of surgical debridement combined with negative-pressure wound therapy, type of surgical flap, postoperative position, and preoperative albumin, leukocyte, C-reactive protein (CRP), and hemoglobin. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The binary multivariate logistic regression analysis was conducted to screen the independent risk factors influencing the poor efficacy after flap repair operation in 125 patients with stage Ⅲ and Ⅳ pressure ulcers. Results: The ratio of patients with lower limb paroxysmal myospasm in poor efficacy group was 22/47, which was significantly higher than 3/78 in good efficacy group (χ2=33.83, P<0.01). The preoperative hemoglobin level of patients in poor efficacy group was (102±17) g/L, which was significantly lower than (113±20) g/L in good efficacy group (t=-3.24, P<0.01). The preoperative CRP level of patients was 39.1 (14.1, 91.6) mg/L in poor efficacy group, which was significantly higher than 15.3 (6.6, 42.0) mg/L in good efficacy group (Z=-3.04, P<0.01). There were no statistically significant differences in other indexes between patients in the two groups (P>0.05). Multivariate logistic regression analysis showed that age, lower limb paroxysmal myospasm, and preoperative hemoglobin level were the independent risk factors for poor efficacy after flap repair operation in patients with pressure ulcers (with odds ratios of 1.03, 40.69, and 0.97, 95% confidence intervals of 1.00-1.06, 9.18-180.39, and 0.95-1.00, respectively, P<0.05 or P<0.01). Conclusions: Poor efficacy after flap repair operation in patients with pressure ulcers is affected by many factors, among which the age, lower limb paroxysmal myospasm, and preoperative hemoglobin level are the independent risk factors.

Association between adolescents' problematic online behaviors and self-harm risk

INTRODUCTION

Problematic online behaviors, including sexting, cyberbullying, and Internet gaming disorder (IGD), were associated with a higher risk of self-harm among adolescents. However, the independent effect on self-harm brought by each problematic online behavior remains unknown.

METHODS

This cross-sectional nationwide survey investigated a representative sample of 8446 Taiwanese adolescents (49.7 % female, mean age = 15.4 ± 1.8, ranging from 10 to 18) in the summer of 2021. We used self-reported questionnaires to assess adolescents' problematic online behaviors. 18-item Risk-Taking and Self-Harm Inventory was applied to evaluate their self-harm risks. Adolescents with score ≥ 7 were considered self-harm identified. Multivariate regression analyses were performed to investigate the association between problematic online behaviors and self-harm risks.

RESULTS

The prevalence of sexting, cyberbullying victimization, cyberbullying perpetration, and IGD was 1.3 %, 1.1 %, 0.9 %, and 0.7 %, respectively. Adolescents with sexting were associated with higher self-harm scores (β = 4.30, 95 % CI [3.35, 5.25]), so did adolescents with IGD (β = 3.33, 95 % CI [1.96, 4.71]), cyberbullying perpetration (β = 2.61, 95 % CI [1.03, 4.20]), and cyberbullying victimization (β = 1.40, 95 % CI [0.04, 2.76]). Also, sexting (OR = 5.16, 95 % CI [3.26, 8.07]) and IGD (OR = 3.11, 95 % CI [1.50, 6.15]) were associated with increased odds of identified self-harm behaviors.

CONCLUSIONS

Sexting, cyberbullying victimization, cyberbullying perpetration, and IGD were all independently associated with an increased self-harm risk among adolescents. Among them, sexting was shown to be the most robust risk factor of identified self-harm behaviors. To prevent self-harm among adolescents, it is important to identify youth involved in problematic online behaviors, especially sexting.

[Research advances on stem cell therapy for diabetic foot wounds]

Diabetic foot wound repair is a challenging issue in clinical practice. Due to the influence of multiple factors including the damage and regeneration failure of local tissue, the impaired pathways of wound repairing through blood vessels and nerve nutrition, and disorders of a variety of cellular factors, traditional treatment methods are often difficult to achieve good therapeutic effects. Stem cells are a type of cells with potentials of multidirectional differentiation, which also possess functions such as regulating immunity and paracrine to facilitate the comprehensive wound repair, so they have promising application prospect at present for the treatment of diabetic foot wounds. Because the relevant parameters of stem cell treatment are in the exploratory phase, there were no standardized data. This paper reviews the application of stem cells in the research of diabetic foot wound treatment over the past 6 years, analyzing and summarizing the contents in focused aspects including the types and sources of stem cells, effects of donor age and gender on stem cells, mode of administration, transplantation survival rate and safety, which may provide a reference for further application of stem cells in the clinical treatment of diabetic foot wound.

Systematic Review and Meta-Analysis of Prevalence of Depression Among Caregivers of Cancer Patients

BACKGROUND

Caregivers of cancer patients commonly experience depressive symptoms due to the heavy burden of caregiving responsibility.

OBJECTIVE

This meta-analysis examined the prevalence of depression among caregivers of cancer patients.

METHODS

We included 85 studies covering 23,317 participants published between 2001 and 2021 (25 countries) that reported the prevalence of depression among caregivers of cancer patients. We examined the pooled prevalence of depression and hypothesized moderators, including year, age, sex, geographic regions, percentage of spousal caregivers, depression measures, and cancer stage.

RESULTS

All 85 effect sizes included 6,077 caregivers of patients with depression. The weighted average prevalence of depression was 25.14% (95% CI, 21.42-29.27%) among caregivers. The prevalence rates were moderated by geographic region, patients' cancer stage, and measures for depression. The prevalence rates also varied among the different measures assessing depression. The prevalence rate decreased with the mean age of the caregivers and the percentage of spousal caregivers.

CONCLUSIONS

This study revealed a high prevalence of depression among caregivers of cancer patients. The prevalence rates also varied with the study design, demographics of caregivers, and patients' medical information. These findings highlight that psychological support and intervention may be crucial for patients and their caregivers in clinical practice.

Relationship Between the Serotypes and Hemagglutinin Gene Sequences of Avibacterium paragallinarum

Avibacterium paragallinarum has been subtyped into three serogroups (A, B, and C) and nine serovars (A-1, A-2, A-3, A-4, B-1, C-1, C-2, C-3, and C-4) according to the Page and Kume schemes. Both schemes use the hemagglutination inhibition test for serotyping. However, the relationship between the hemagglutinin gene (HMTp210) sequences and serotypes of A. paragallinarum is still unclear. This problem is partly due to the lack of information on the complete HMTp210 sequence from the formal reference strain of Page serogroup B (strain 0222 or Spross). In this study, we determined the complete HMTp210 sequence of strain Spross. The sequence of Spross and those of other HMTp210 sequences retrieved from GenBank were used to conduct phylogenetic analyses to investigate the relationship between the serotypes and HMTp210 sequences of A. paragallinarum. Four phylogenetic clusters, designated clusters A-1, A-2, B, and C, were identified. Clustering based on complete HMTp210 sequences correlates with serotyping based on hemagglutination inhibition tests. Serovar A-2 was found to contain a chimeric HMTp210 gene that might have resulted from recombination between serovar A-1 and serovar C-1. In addition, phylogenetic analysis based on partial sequences (approximately nucleotides 1-1200) of HMTp210 was sufficient to discriminate between serogroups A, B, and C. These findings could be valuable for developing a molecular method for serotyping of A. paragallinarum.

Assessing User Retention of a Mobile App: Survival Analysis

BACKGROUND

A mobile app generates passive data, such as GPS data traces, without any direct involvement from the user. These passive data have transformed the manner of traditional assessments that require active participation from the user. Passive data collection is one of the most important core techniques for mobile health development because it may promote user retention, which is a unique characteristic of a software medical device.

OBJECTIVE

The primary aim of this study was to quantify user retention for the "Staff Hours" app using survival analysis. The secondary aim was to compare user retention between passive data and active data, as well as factors associated with the survival rates of user retention.

METHODS

We developed an app called "Staff Hours" to automatically calculate users' work hours through GPS data (passive data). "Staff Hours" not only continuously collects these passive data but also sends an 11-item mental health survey to users monthly (active data). We applied survival analysis to compare user retention in the collection of passive and active data among 342 office workers from the "Staff Hours" database. We also compared user retention on Android and iOS platforms and examined the moderators of user retention.

RESULTS

A total of 342 volunteers (224 men; mean age 33.8 years, SD 7.0 years) were included in this study. Passive data had higher user retention than active data (P=.011). In addition, user retention for passive data collected via Android devices was higher than that for iOS devices (P=.015). Trainee physicians had higher user retention for the collection of active data than trainees from other occupations, whereas no significant differences between these two groups were observed for the collection of passive data (P=.700).

CONCLUSIONS

Our findings demonstrated that passive data collected via Android devices had the best user retention for this app that records GPS-based work hours.

Investigation of the Role of Anxiety and Depression on the Formation of Phantom Vibration and Ringing Syndrome Caused by Working Stress during Medical Internship

Phantom vibration syndrome (PVS) and phantom ringing syndrome (PRS) are prevalent hallucinations during medical internship. Depression and anxiety are probably understudied risk factors of PVS and PRS. The aim was to evaluate the role of anxiety and depression on the relationship between working stress during medical internship and PVS and PRS. A prospective longitudinal study, consisted of 74 medical interns, was carried out. The severity of phantom vibrations and ringing, as well as anxiety and depression as measured before, at the third, sixth, and 12th month during internship, and two weeks after internship. We conducted a causal mediation analysis to quantify the role of depression and in the mechanism of working stress during medical internship inducing PVS and PRS. The results showed that depression explained 21.9% and 8.4% for stress-induced PRS and PVS, respectively. In addition, anxiety explained 15.0% and 7.8% for stress-induced PRS and PVS, respectively. Our findings showed both depression and anxiety can explain a portion of stress-induced PVS and PRS during medical internship and might be more important in clinical practice and benefit to prevention of work-related burnout.

Systematic review and meta-analysis of epidemiology of internet addiction

BACKGROUND

The field of internet addiction has experienced significant debates on conflicting epidemiology. This meta-analysis investigated the prevalence rates of generalized internet addiction (GIA) and internet gaming disorder (IGD).

METHODS

We included 113 epidemiologic studies covering 693,306 subjects published from 1996 to 2018 (for 31 nations) that reported prevalence rates for GIA or IGD. We examined pooled prevalence of GIA and IGD and the hypothesized moderators including year, geographic regions, types of scales, and sample representativeness.

RESULTS

All 133 effect sizes included 53,184 subjects with GIA or IGD. Weighted average prevalence for GIA and IGD were 7.02 % (95 % CI, 6.09 %-8.08 %) and 2.47 % (95 % CI, 1.46 %-4.16 %) respectively. For GIA, prevalence was increased over time and prevalence rates variated among different scales. IGD prevalence was neither moderated by year, regions, nor sample representativeness.

CONCLUSIONS

The prevalence of GIA was higher than the prevalence of IGD. The GIA prevalence was increasing over time and variated with different assessments. Our results reveal that GIA may reflect a pattern of increasing human-machine interaction.

Automatic Work-Hours Recorder for Medical Staff (Staff Hours): Mobile App Development

Background

There are numerous mobile apps for tracking work hours, but only a few of them record work hours automatically instead of relying on manual logging. No apps have been customized for medical staff, whose work schedules are highly complicated as they have both regular hours and on-call duties.

Objective

The specific aims of this study were to (1) identify the Staff Hours app users’ GPS-defined work hours, (2) examine the overtime work hours from the app-recorded total work hours and the participants’ self-reported scheduled work hours, and (3) compare these app-recorded total work hours among different occupations.

Methods

We developed an app, Staff Hours, to automatically calculate a user’s work hours via GPS background data. Users can enter their scheduled hours, including regular hours and on-call duties. The app automatically generates overtime reports by comparing the app-recorded total work hours with the user-defined scheduled hours. A total of 183 volunteers (60 females and 123 males; mean age 32.98 years, SD 6.74) were included in this study. Most of the participants (162/183, 88.5%) were medical staff, and their positions were resident physicians (n=89), visiting staff (n=38), medical students (n=10), registered nurses (n=25), and non–health care professionals (non-HCPs; n=21).

Results

The total work hours (mean 55.69 hours, SD 21.34) of the 183 participants were significantly higher than their scheduled work hours (mean 50.67 hours, SD 21.44; P=.01). Medical staff had significantly longer total work hours (mean 57.01 hours, SD 21.20) than non-HCPs (mean 45.48 hours, SD 20.08; P=.02). Residents (mean 60.38 hours, SD 18.67) had significantly longer work hours than visiting staff (mean 51.42 hours, SD 20.33; P=.03) and non-HCPs (mean 45.48 hours, SD 20.08; P=.004).

Conclusions

Staff Hours is the first automatic GPS location–based app designed for medical staff to track work hours and calculate overtime. For medical staff, this app could keep complete and accurate records of work hours in real time, reduce bias, and allow for better complying with labor regulations.

Validation of the Mobile App-Recorded Circadian Rhythm by a Digital Footprint

Background

Modern smartphone use is pervasive and could be an accessible method of evaluating the circadian rhythm and social jet lag via a mobile app.

Objective

This study aimed to validate the app-recorded sleep time with daily self-reports by examining the consistency of total sleep time (TST), as well as the timing of sleep onset and wake time, and to validate the app-recorded circadian rhythm with the corresponding 30-day self-reported midpoint of sleep and the consistency of social jetlag.

Methods

The mobile app, Rhythm, recorded parameters and these parameters were hypothesized to be used to infer a relative long-term pattern of the circadian rhythm. In total, 28 volunteers downloaded the app, and 30 days of automatically recorded data along with self-reported sleep measures were collected.

Results

No significant difference was noted between app-recorded and self-reported midpoint of sleep time and between app-recorded and self-reported social jetlag. The overall correlation coefficient of app-recorded and self-reported midpoint of sleep time was .87.

Conclusions

The circadian rhythm for 1 month, daily TST, and timing of sleep onset could be automatically calculated by the app and algorithm.

Temporal Stability of Smartphone Use Data: Determining Fundamental Time Unit and Independent Cycle

Background

Assessing human behaviors via smartphone for monitoring the pattern of daily behaviors has become a crucial issue in this century. Thus, a more accurate and structured methodology is needed for smartphone use research.

Objective

The study aimed to investigate the duration of data collection needed to establish a reliable pattern of use, how long a smartphone use cycle could perpetuate by assessing maximum time intervals between 2 smartphone periods, and to validate smartphone use and use/nonuse reciprocity parameters.

Methods

Using the Know Addiction database, we selected 33 participants and passively recorded their smartphone usage patterns for at least 8 weeks. We generated 4 parameters on the basis of smartphone use episodes, including total use frequency, total use duration, proactive use frequency, and proactive use duration. A total of 3 additional parameters (root mean square of successive differences, Control Index, and Similarity Index) were calculated to reflect impaired control and compulsive use.

Results

Our findings included (1) proactive use duration correlated with subjective smartphone addiction scores, (2) a 2-week period of data collection is required to infer a 2-month period of smartphone use, and (3) smartphone use cycles with a time gap of 4 weeks between them are highly likely independent cycles.

Conclusions

This study validated temporal stability for smartphone use patterns recorded by a mobile app. The results may provide researchers an opportunity to investigate human behaviors with more structured methods.

Development of a mobile application (App) to delineate "digital chronotype" and the effects of delayed chronotype by bedtime smartphone use

The widespread use and deep reach of smartphones motivate the use of mobile applications to continuously monitor the relationship between circadian system, individual sleep patterns, and environmental effects. We selected 61 adults with 14-day data from the "Know Addiction" database. We developed an algorithm to identify the "sleep time" based on the smartphone behaviors. The total daily smartphone use duration and smartphone use duration prior to sleep onset were identified respectively. We applied mediation analysis to investigate the effects of total daily smartphone use on sleep through pre-sleep use (PS). The results showed participants' averaged pre-sleep episodes within 1 h prior to sleep are 2.58. The duration of three pre-sleep uses (PS_1∼3) maybe a more representative index for smartphone use before sleep. Both total daily duration and the duration of the last three uses prior to sleep of smartphone use significantly delayed sleep onset, midpoint of sleep and reduced total sleep time. One hour of increased smartphone use daily, delays the circadian rhythm by 3.5 min, and reduced 5.5 min of total sleep time (TST). One hour of increased pre-sleep smartphone use delayed circadian rhythm by 1.7 min, and reduced 39 s of TST. The mediation effects of PS_1∼3 significantly impacted on these three sleep indicators. PS_1∼3 accounted for 14.3% of total daily duration, but the proportion mediated of delayed circadian rhythm was 44.0%. We presented "digital chronotype" with an automatic system that can collect high temporal resolution data from naturalistic settings with high ecological validity. Smartphone screen time, mainly mediated by pre-sleep use, delayed the circadian rhythm and reduced the total sleep time.

Chinese adaptation of the Ten-Item Internet Gaming Disorder Test and prevalence estimate of Internet gaming disorder among adolescents in Taiwan

BACKGROUND AND AIMS

Internet gaming disorder (IGD) is an increasingly important topic and has been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) research criteria. This study aims to validate the Chinese version of the Ten-Item Internet Gaming Disorder Test (IGDT-10), a self-reported questionnaire based on DSM-5 IGD criteria, and to estimate the prevalence of IGD in adolescents.

METHODS

The IGDT-10 was translated to Chinese as a 10-item questionnaire rated on a 3-point Likert scale to evaluate the symptoms of IGD. Overall, 8,110 students from grade four to senior high who played Internet games were administered the questionnaire. In addition, 76 senior high-school students were interviewed using DSM-5 criteria to determine the optimal cut-off point that ensures adequate sensitivity, specificity, and diagnostic accuracy. The cut-off point was determined using the Youden's index and optimal diagnostic accuracy.

RESULTS

The Chinese version of the IGDT-10 showed good internal consistency (Cronbach's α = .85) and adequate diagnostic efficiency (area under the curve = 0.810). Through interviews, the optimal cut-off point was determined to be five out of the nine criteria (Youden's index: 42.1%, diagnostic accuracy: 86.8%, sensitivity: 43.8%, and specificity: 98.3%). In this study, the prevalence of IGD among adolescent gamers was 3.1%.

CONCLUSION

Findings evidence the validity and diagnostic accuracy of the IGDT-10 in the assessment of IGD.

Development of short-form and screening cutoff point of the Smartphone Addiction Inventory (SPAI-SF)

Smartphone addiction is considered a form of technological addiction that has attracted increasing attention. The present study developed and validated the short-form Smartphone Addiction Inventory (SPAI-SF) and established cutoff point for screening smartphone addiction based on diagnostic criteria established by psychiatric interview. A total of 268 participants completed an online survey that collected demographic data, smartphone use behaviours, and responses to the 26-item SPAI. Each participant also completed a psychiatric interview. Confirmatory factor analysis (CFA) revealed that the 10-item SPAI-SF replicated the structure of original 26-item SPAI accurately, yielding a four-factor model consisting of compulsive behaviour, functional impairment, withdrawal, and tolerance. For maximal diagnostic accuracy, a cutoff point of 24/25 best discriminated cases of smartphone addiction from diagnostic negatives. The present findings suggest that both the 26-item SPAI and SPAI-SF manifest the four constructs of behavioural addiction and the characteristics of smartphone addiction. The cutoff point determined by psychiatrists' diagnostic interview will be useful for clinical screening and epidemiologic research.

Smartphone gaming and frequent use pattern associated with smartphone addiction

The aim of this study was to investigate the risk factors of smartphone addiction in high school students.A total of 880 adolescents were recruited from a vocational high school in Taiwan in January 2014 to complete a set of questionnaires, including the 10-item Smartphone Addiction Inventory, Chen Internet Addiction Scale, and a survey of content and patterns of personal smartphone use. Of those recruited, 689 students (646 male) aged 14 to 21 and who owned a smartphone completed the questionnaire. Multiple linear regression models were used to determine the variables associated with smartphone addiction.Smartphone gaming and frequent smartphone use were associated with smartphone addiction. Furthermore, both the smartphone gaming-predominant and gaming with multiple-applications groups showed a similar association with smartphone addiction. Gender, duration of owning a smartphone, and substance use were not associated with smartphone addiction.Our findings suggest that smartphone use patterns should be part of specific measures to prevent and intervene in cases of excessive smartphone use.

Yeast CUP1 protects HeLa cells against copper-induced stress

As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. YeastCUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study,CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.

[Clinical outcome evaluation of midpalatal mini-implant anchorage system in orthodontic treatment]

OBJECTIVE

To evaluate the effect of midpalatal mini-implant anchorage system in fixed appliance treatment.

METHODS

In this study, 14 adolescents who had skeletal class I or II malocclusions were involved. Maximal anchorage was required during orthodontic treatment. Maxillary first premolars of the selected individuals were extracted and the individuals were treated by fixed appliance. One mini-implant was inserted in the midpalatal suture region and a transpalatal arch (TPA) made of 0.019 inch×0.022 inch(1 inch=2.54 cm) stainless steel was adhered to the mini-implant and upper first molars. Cephalometric radiographs taken after mini-implants inserted (T0) and before mini-implants removing (T1) were traced and measured. SN-7 plane and PP plane were used as reference planes. Student's t-test was used.

RESULTS

The successful rate of midpalatal mini-implant was 73.9%. All the items measured were found with no significant difference between the two groups.

CONCLUSION

This mini-implant system as orthodontic anchorage in midpalatal region can be an alternative method of maximal anchorage during orthodontic treatment.

Molecular characteristics and expression profiles of glycerol-3-phosphate dehydrogenase 1 (GPD1) gene in pig

The cytosolic activity of glycerol-3-phosphate dehydrogenase 1 (GPD1, EC 1.1.1.8) plays an important role in the synthesis of triacylglycerol and in the transport of reducing equivalents from the cytosol to mitochondria. Here we report the full-length genomic sequence of porcine GPD1 gene including promoter region. Porcine GPD1 gene contains eight exons and seven introns. Using the ImpRH, the GPD1 gene was mapped on chromosome 5. Sub-cellular localization of the pig GPD1 was localized in cytoplasm by GFP reporter gene. The full-length CDS of porcine GPD1 gene comprises 1050 nucleotides and it encodes 349 amino acids. Using the CDS sequences of 17 species, we built the phylogeny tree of GPD1 gene. We investigated the expression level of the gene in 13 different tissues and time course from birth to postnatal day 28 in longissinus doris muscle (LD) and in cerebrum. The result shows that porcine GPD1 gene is expressed in almost all tissues we tested but its levels of expression varies widely over 2 orders of magnitude. LD and the cerebrum have similar expression pattern that is at a low level at birth and increasing with aging to the highest level at postnatal day 8 in LD and postnatal day 14 in cerebrum. But weaning decreased the expression level of the GPD1 gene. This may partially explains the effects of weaning on energy metabolism.

Inhibition of gene expression directed by small interfering RNAs in infectious bronchitis virus

In this study, fourteen small interfering RNAs (siRNAs) were synthesized for targeting of coding gene sequences, specific 5'-leader sequence of mRNA and 3'-end sequence of the Infectious bronchitis virus (IBV) genome. The expression of viral genes in Vero-E6 cells was detected by real-time PCR. Obtained results indicated that the majority of siRNAs could effectively inhibit the expression of viral genes. The inhibition effect of siRNAs significantly differed among various genes and sites on the virus genome.

[Repair of flexor-tendon injury in children's finger using microsurgical technique]

OBJECTIVE

To improve the clinical result of repair on flexor tendon injury, and recover the defected finger function in children as far as possible.

METHODS

From January 1990 to October 1997, 12 cases with flexor tendon injury were repaired by microsurgical technique, sutured by modified Kessler method with 3/0 or 5/0 nontraumatic thread and followed by invering suture of the gap edge with 7/0 or 8/0 nontraumatic thread after debridement. Appropriate functional practice was performed postoperatively.

RESULTS

All the defected fingers were healed by first intention. Followed up 6 months to 1 year, there was excellent in 7 cases, better in 4 cases, moderate in 1 case and 91.67% in excellent rate according to the TAM standard of International Hand Committee.

CONCLUSION

The important measures to improve the clinical result in children's flexor tendon injury are prompt and accurate diagnosis and repair of the injured tendon by microsurgical technique, and effective postoperative functional practice.

Increased axonal regeneration through a biodegradable amnionic tube nerve conduit: effect of local delivery and incorporation of nerve growth factor/hyaluronic acid media

The authors emphasize the possible pharmacological enhancement of axonal regeneration using a specific growth factor/ extracellular media incorporated in a biodegradable nonneural nerve conduit material. They investigated the early effects on nerve regeneration of continuous local delivery of nerve growth factor (NGF) and the local incorporation of hyaluronic acid (HA) inside a newly manufactured nerve conduit material from fresh human amnionic membrane. Human amnionic membrane contains important biochemical factors that play a major neurotrophic role in the nerve regeneration process. The process of manufacturing a nerve conduit from fresh human amnionic membrane is described. This nerve conduit system was used in rabbits to bridge a 25-mm nerve gap over 3 months. NGF was released locally, over 28 days, at the distal end of the tube via a system of slow release, and HA was incorporated inside the lumen of the tube at the time of surgery. NGF/HA treatment promoted axonal regeneration across the amnionic tube nerve conduit (8,962 +/- 383 myelinated axons) 45% better than the nontreated amnionic tube group (6,180 +/- 353 myelinated axons). The authors demonstrate that NGF/HA media enhances additional axonal regeneration in the amnionic tube nerve conduit. This result is secondary to the effect of the amnion promoting biochemical factors, in combination with the NGF/HA effect on facilitating early events in the nerve regeneration process.

Using native gel in two-dimensional PAGE for the detection of protein interactions in protein extract

A two-dimensional (2-D) gel electrophoresis system in which native and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) are performed subsequently to analyze protein mixtures is described. Reasonably good resolution and excellent reproducibility was obtained when the proteins in the soluble protein extract from E. coli cells were separated using this procedure. Perhaps more importantly, the relevance of this native/SDS-2-D PAGE for the detection of protein interactions in a complicated protein mixture was examined using the interaction between interleukin-2 (IL-2) and its receptor alpha chain (IL-2Ralpha) in the E. coli protein extract as a model system. Native gel was used to preserve the interactions between the two molecules and SDS gel was used to maximize the separation of the denatured proteins. Mobility changes of these two proteins on 2-D maps resulted from the formation of IL-2/IL-2-2Ralpha complex were clearly observed despite of the presence of a large number of other protein spots. Thus, this approach is a useful complement to the standard 2-D gel electrophoresis system for analyzing complicated protein mixture, especially for the study of protein interactions.

Results of laser tissue soldering in vasovasostomy and epididymovasostomy: experience in the rat animal model

The use of microsurgical techniques (vasovasostomy and epididymovasostomy) for vasectomy reversal has now enabled surgeons to perform both procedures with certainly acceptable success rates. However, these operations are technically demanding and require special training in microsurgery.

PURPOSE

A new method of performing these procedures using laser tissue soldering is described and results are evaluated. Laser tissue soldering is different from laser welding in that it involves the laser activation of a protein solder with a dye specific for the specific wavelength of laser light; therefore, surrounding tissue is not affected by the laser.

MATERIALS AND METHODS

Ten rats underwent bilateral vasovasostomy and eleven underwent bilateral epididymovasostomy. In each rat, a sutured anastomosis was performed on one side while laser tissue soldering was performed on the other. Animals were sacrificed after one month and anastomoses were evaluated for patency and presence of sperm granulomas. Histologic analysis was also performed.

RESULTS

Patency rates were 8/10 (80%) for sutured vasovasostomy versus 9/10 (90%) for the laser technique. Epididymovasostomy patency rates were 8/11 (73%) for sutured versus 9/11 (82%) for the laser technique. Mean operative times were significantly shorter for lasered anastomoses when compared to controls. The frequency of granuloma formation did not significantly differ between laser and control groups.

CONCLUSIONS

Laser tissue soldering resulted in similar patency when compared to a conventional 2 layered sutured anastomosis while decreasing operative time. In addition, since fewer sutures are placed, the laser method is less technically demanding.

Positional isomers of monopegylated interferon alpha-2a: isolation, characterization, and biological activity

The success of recombinant interferon alpha in the clinic in part is limited by two properties of the protein: short serum half-life and immunogenicity. To improve these properties, interferon alpha-2a was conjugated with polyethylene glycol (PEG-5000). A homogeneous preparation of monopegylated interferon alpha-2a was subjected to vigorous analytical and activity characterization. A newly developed ampholyte-free chromatofocussing-like cation-exchange HPLC method utilizing a sulfopropyl resin was used to separate the monopegylated protein into 11 species. Peptide mapping, sequencing, and mass spectrometric analyses indicated that these species are positional isomers where each isomer represents a single polymer molecule conjugated to one specific lysine residue. No species with a modification at the amino terminus was observed. All 11 isomers show antiviral and antiproliferative activities in the same range as the parent monopegylated interferon alpha-2a.

Gene expression and apoptosis in the spinal cord neurons after sciatic nerve injury

To demonstrate a dependence of spinal cord motoneurons on the communication with their targets, the expression of immediate early gene c-fos and neurotrophin genes in the lumbar (L3-L6) spinal cord neurons was examined in Sprague-Dawley rats (male > or = 9-weeks-old) with unilateral sciatic nerve transection. Using in situ hybridization, we detected the expression of c-fos mRNA in the motoneurons of the spinal cord segments within 45 min to 3 h of peripheral nerve transection (n = 4 in each time point). The expression of c-fos mRNA was also correlated positively with the expression of Fos antigen using immunohistochemistry, while no change in calbindin and parvalbumin antigens were noted. The expression of BDNF mRNA increased at 90 min after sciatic nerve transection. However, no detectable enhancement in the expression of NGF mRNA was observed. DNA fragmentation in neurons was observed using the incorporation of digoxigenin-dUTP by terminal transferase into 3'-OH terminals of DNA fragments in the ipsilateral section of the spinal cords 48h after nerve injury. Nuclei that exhibited DNA fragmentation were not observed in the spinal cord of the control animals. Lastly, we observed that the majority of astrocytes did not have DNA fragmentation. Because the detection of DNA fragmentation using this assay is one of early detections of apoptosis or programmed cell death, the result suggested we could detect early cell death in spinal cord, and indicated a target dependence of the neurons in the spinal cord after transection of sciatic nerve.

Functional assessment of tibial-nerve recovery in the cat using gait analysis: preliminary study

The purpose of this study was to investigate gait-pattern changes after complete tibial nerve lesion in the cat, and to observe whether nerve repair could reverse some of the changes. In six cats, a 5-cm segment of the tibial nerve was transected. The nerve gap was then repaired with nerve autograft in three animals and was unrepaired in three as controls. The walking patterns of the cats were videotaped, and the hip, knee, ankle, and metatarsophalangeal joint angles were measured at the beginnings of the F, E1, E2, and E3 phases of the step cycle. Two weeks after surgery, abnormal gait patterns were observed, and four gait parameters (E3.Hip, E3.Ankle, E3.M-P, and F.Ankle) were found to be statistically significantly different from normal. Six months after surgery, the nerve-graft group had gait-parameter values approaching normal, while the control group showed no measurable improvement. Correspondingly, electrophysiologic testing revealed considerable nerve regeneration in the nerve-graft group but not in the control group. It was concluded that these gait parameters can be used as valid functional indices to evaluate the degree of tibial nerve recovery in the cat model.

Elevated expression of the neutrophil calcium-binding protein, MRP-14, in metastasis-enhancing neutrophils

Tumor-elicited neutrophils (tcPMN) purified from 13762NF mammary adenocarcinoma tumor-bearing rats enhanced metastasis of syngeneic cells when co-injected intravenously; whereas, circulating (cPMN) and phorbol esteractivated (PMA-PMN) neutrophils did not [Welch et al. (1989) Proc. Natl. Acad. Sci. 86:5859-63]. We hypothesized that differential protein expression was responsible for functional differences between the neutrophil subtypes. Two-dimensional polyacrylamide gel electrophoresis was used to compare neutrophils (cPMN, PMA-PMN) purified from the peripheral blood of healthy, syngeneic nontumor-bearing rats, to tcPMN collected from rats with highly metastatic [clone MTLn3, subclone MTLn3(T44).5] or poorly metastatic [subclone MTLn3(T44).11] tumors growing in the mammary fat pads. Quantitative differences in polypeptide expression were observed between these functionally distinct PMN populations. Compared to cPMN, expression of a M(r) approximately 38.8 kDa (pl approximately 8) polypeptide was similar in tcPMN collected from poorly metastatic tumor-bearing rats, higher in PMA-PMN, and further increased in tcPMN from rats with highly metastatic tumors. Expression of two polypeptides, M(r) approximately 14.1 kDa (pl approximately 6) and M(r) approximately 43.3 kDa (pl approximately 5), was greater in tcPMN from rats with highly metastatic tumors compared to cPMN, PMA-PMN, or tcPMN from rats bearing poorly metastatic tumors. The latter two polypeptides thus appeared to be specifically increased in tcPMN from rats bearing highly metastatic tumors. Because it was most abundant and displayed the greatest differences between PMN subtypes, the M(r) approximately 14.1 kDa protein was further analyzed. Tryptic digests followed by internal sequence analyses of resulting peptide fragments revealed that the M(r) approximately 14.1 kDa contained amino acid sequences that were identical to those of MRP-14, a 14 kDa neutrophil calcium-binding protein belonging to the S-100 protein family of calcium-binding proteins. These results suggest a novel function for MRP-14 and suggest that MRP-14 may represent a marker for distinguishing phenotypically distinct subpopulations of neutrophils, particularly tcPMN with metastasis-enhancing abilities.

Ankle stance angle: a functional index for the evaluation of sciatic nerve recovery after complete transection

This study attempted to develop a motor functional index, ankle stance angle (ASA), to assess rat sciatic nerve regeneration subsequent to autografting. ASA, 50 degrees in normal rats, is the ankle joint angle at the mid-stance phase of the gait cycle. In a nerve graft group, a 1-cm segment of the right sciatic nerve was transected and then repaired with nerve autograft. In an ungrafted group, the nerve gap was left unrepaired. ASA measured 4 months after surgery was statistically significantly larger in the nerve graft group (36 degrees) than in the ungrafted group (22 degrees). The results suggest that ASA is more sensitive than sciatic function index in detecting functional recovery after a complete sciatic nerve lesion. ASA also showed a significant correlation with the passive range of ankle joint motion and gastrocnemius muscle weight. The study concluded that ASA is a reliable index for assessment of regeneration of rat sciatic nerve after a complete lesion. The intra-rater reliability (r = 0.97 and 0.90) and inter-rater reliability (r = 0.85) tests performed support the conclusions.

Immunoregulatory effects of indomethacin on rats with trauma

In this article, we investigated changes of immune functions and immunoregulatory effects of indomethacin on rats with trauma. The results show that spontaneous suppressor T cell activity of spleen significantly increased and Interleukin I production and DNA synthesis capacity of splenocytes markedly decreased in rats with trauma. Indomethacin could markedly improve immune function, decreased spontaneous suppressor T cell activity and prompted Interleukin 2 production and DNA synthesis capacity of splenocytes.

Experimental orthotopic transplantation of vascularized skeletal allografts: functional assessment and long-term survival

Vascularized skeletal tissue allografts would greatly expand the domain of reconstructive surgery. Few studies to date have examined the functional aspects of these allografts or their long-term fate. An orthotopic transplant model of rat distal femur and surrounding muscular cuff was developed to assess graft function in fracture healing and weight bearing. Isografts (RT1l to RT1l, n = 40), weak-barrier allografts (RT1l to RT1lv, n = 40), and strong-barrier allografts (RT1l to RT1n, n = 40) were transplanted. As the histocompatibility barrier increased between the donor and recipient animals, the graft viability and performance deteriorated according to radiographic, histologic, and immunologic analyses. Administration of cyclosporine led to survival of strong-barrier allografts similar to that of isografts. A long-term study of these allografts (RT1l to RT1n) was then performed on various immunosuppressive regimens. After an initial 10-week course of cyclosporine to achieve bony union and remodeling, subsequent cessation (n = 20) or intermittent "pulsing" (n = 20) of the immunosuppressant was insufficient in maintaining graft survival. However, graft viability and function were preserved through 1 year on continuous daily cyclosporine (n = 32). There was no evidence of host renal or hepatic toxicity by serum chemistry or histologic sections. Thus long-term survival of functional skeletal allografts was achieved in this orthotopic model without significant host toxicity from immunosuppression.

Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity

IL-12, a heterodimeric cytokine, consists of two disulfide-linked subunits, p40 and p35. We investigated the role of p40 in ligand binding and signal transduction by expressing this subunit alone in COS cells. Culture media of the transfected COS cells exhibited specific dose-dependent binding to KIT225/K6 cells, a human T cell line that expresses IL-12R. Analysis of the culture media by SDS-PAGE and Western blotting demonstrated the presence of 40-kDa monomers and 80-kDa disulfide-linked homodimers. The two p40 species were purified and identified by N-terminal sequencing and proteolytic peptide mapping. Characterization of the p40 proteins for binding and bioactivity showed that both the p40 monomer and dimer inhibited 125I-labeled IL-12 binding to IL-12R, but the 80-kDa species, having a 50% inhibitory concentration (IC50) of 20 to 70 ng/ml, was at least 20-fold more effective than the monomer. Although neither the monomer nor the dimer stimulated human PHA-blast proliferation, the 80-kDa dimer inhibited IL-12-induced proliferation in a dose-dependent manner with an IC50 of 65 ng/ml. The results suggest that the IL-12 p40 subunit contains the essential epitopes for receptor binding. However, a proper conformation required for high affinity binding is achieved only when p40 is associated with a p35 subunit or another p40 subunit. When p40 is associated with a p35 subunit, the heterodimer acts as an agonist mediating biologic activity. However, when p40 associates with another p40, the homodimer behaves as an antagonist in vitro.

Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity

IL-12, a heterodimeric cytokine, consists of two disulfide-linked subunits, p40 and p35. We investigated the role of p40 in ligand binding and signal transduction by expressing this subunit alone in COS cells. Culture media of the transfected COS cells exhibited specific dose-dependent binding to KIT225/K6 cells, a human T cell line that expresses IL-12R. Analysis of the culture media by SDS-PAGE and Western blotting demonstrated the presence of 40-kDa monomers and 80-kDa disulfide-linked homodimers. The two p40 species were purified and identified by N-terminal sequencing and proteolytic peptide mapping. Characterization of the p40 proteins for binding and bioactivity showed that both the p40 monomer and dimer inhibited 125I-labeled IL-12 binding to IL-12R, but the 80-kDa species, having a 50% inhibitory concentration (IC50) of 20 to 70 ng/ml, was at least 20-fold more effective than the monomer. Although neither the monomer nor the dimer stimulated human PHA-blast proliferation, the 80-kDa dimer inhibited IL-12-induced proliferation in a dose-dependent manner with an IC50 of 65 ng/ml. The results suggest that the IL-12 p40 subunit contains the essential epitopes for receptor binding. However, a proper conformation required for high affinity binding is achieved only when p40 is associated with a p35 subunit or another p40 subunit. When p40 is associated with a p35 subunit, the heterodimer acts as an agonist mediating biologic activity. However, when p40 associates with another p40, the homodimer behaves as an antagonist in vitro.

Electrophoresis of proteins and protein-protein complexes in native polyacrylamide gels using a horizontal gel apparatus

Electrophoresis of proteins and protein-protein complexes in polyacrylamide gels under native conditions using a horizontal gel apparatus is described. The advantage of this system is that it permits the detection of both negatively and positively charged proteins as well as protein-protein complexes in the same gel. During electrophoresis, a continuous gel sandwiched between two glass plates is placed horizontally on the platform and submerged in a reservoir buffer. The sample wells are made along the center of the gel, allowing positively and negatively charged proteins to migrate toward the cathode and anode, respectively. Several proteins with varying molecular weights and isoelectric point (pI) values and pairs of proteins capable of forming protein-protein complexes were chosen as model systems to illustrate the methodology. The effects of several parameters on the performance of the gel system including protein molecular weight, pI, and gel concentration were also examined and the results obtained by this method are comparable to those obtained by the vertical system. Following electrophoresis, both negatively and positively charged proteins as well as protein-protein complexes can be transferred by electroblotting onto polyvinylidene difluoride membranes for further analyses.

Purification and characterization of a high-molecular-weight form of recombinant human interleukin-2

During purification of recombinant Interleukin-2 (rIL-2) by reversed-phase HPLC, early fractions are discarded due to the presence of an unidentified form of rIL-2. A procedure has been developed to isolate and purify this unidentified form of rIL-2. The purification process involves two chromatography steps and utilizes a Bakerbond Carboxy-Sulfon (CS) column under two different conditions. This material, designated as a high-molecular-weight form of rIL-2 (HMWrIL-2), exhibits lower mobility during SDS-PAGE and has a pI which is approximately one unit less than that of rIL-2, but has similar bioactivity to rIL-2. Structural analysis through enzymatic cleavage, HPLC peptide mapping, mass spectrometry, sequencing, and amino acid composition revealed that the difference between these two proteins is a C-terminal extension of 11 amino acids. This extension could be the result of a nonstandard translation event.

A novel accessory subunit for vacuolar H(+)-ATPase from chromaffin granules

Three subunits, Ac115, Ac39, and the proteolipid, were positively identified in the membrane sectors of V-ATPases from different sources. We searched for organelle-specific protein in purified preparations of V-ATPase from bovine chromaffin granules. A diffused protein band at a position of about 45 kDa was identified in SDS-polyacrylamide gels of the above preparation. Following digestion with endopeptidase Glu-C (V-8), a polypeptide of about 10 kDa was isolated and subjected to amino acid sequencing. Hence, the cDNA encoding the protein Ac45 was cloned from a bovine adrenal medulla library. The cDNA sequence contains an open reading frame encoding a protein of 468 amino acids with a calculated molecular mass of 51,786 daltons. A potential signal sequence comprised of the first 35 amino acids and a potential transmembrane domain at the C terminus of the protein were identified. There exist seven potential glycosylation sites between the aforementioned protein motifs. Experiments with a specific antibody against Ac45 demonstrated that it is copurifying with the V-ATPase from chromaffin granules. Immunological cross-reactivity was observed with purified V-ATPase from bovine kidney microsomes but not from plasma membranes of epithelial cells. Cell-free expression of the protein from synthetic mRNA produced a single protein band at about 50 kDa on SDS gels. Upon inclusion of dog pancreas microsomes in the reaction mixture, a slow migrating band sensitive to peptide:N-glycosidase F was observed.

Electroblotting proteolytic products from native gel for direct N-terminal sequence analysis: an approach for studying protein-protein interaction

Proteins which are electroblotted from native gels onto polyvinylidene difluoride (PVDF) membranes are suitable for detailed structural analysis. This method, in conjunction with limited proteolysis and N-terminal sequencing, has been used to study the molecular interactions between native protein molecules. The interaction between recombinant interleukin-2 (rIL-2) and its receptor (rIL-2R alpha) was examined as a model system. The working strategy consists of (i) proteolysis of rIL-2R alpha and rIL-2R alpha/rIL-2 complex, (ii) separation of the major proteolytic products by native polyacrylamide gel electrophoresis followed by electroblotting onto PVDF membrane, and (iii) sequence analysis of the blotted protein bands for the identification of peptide regions sensitive to proteolysis. Results have indicated that the exon 3 encoded region in rIL-2R alpha is sensitive to proteolysis regardless whether it is complexed with rIL-2 or not. This suggests that no major conformational changes occur in rIL-2R alpha during interaction with rIL-2. This electroblotting approach is, therefore, useful for studying protein-protein interaction in solution.

[Analysis of keratin filament structural transformation in human epithelial cells]

Upon 2-3 hours cold treatment (0 degrees C), the keratin filaments of some PcaSE-1 cells and BEL-7404 cells are partly transformed into granular aggregates. But such structural transformation does not occur in HeLa cells and CNE cells. By rewarming (37 degrees C) cells within 15-30 minutes, this structural changes of keratin filaments in PcaSE-1 cells and BEL-7404 cells are readily reversed. In contrast, in HeLa cells and CNE cells, keratin filaments are transformed into granula aggregates during mitosis, but the keratin filament network in PcaSE-1 cells and BEL-7404 cells remained intact and encircled the developing mitotic spindle as the cells entered mitosis. Results suggest that the above two types of keratin filament structural transformation might be induced by different factors. Our results also indicate that: (1) PcaSE-1 cells treated with colchicine alone or with combination of colchicine and cytochalasin D does not cause granular aggregates of keratin filaments. However, after depolymerization of microtubules with colchicine, the response of the cells to cold treatment is intensified. (2) The aggregate formation during cold treatment is unrelated to whether epithelial cells contain two different type intermediate filaments or not. (3) Epithelial cells preextracted with Triton X-100 do not induce granular aggregate formation of keratin filaments upon cold treatment. (4) The structural transformation upon cold treatment may be a characteristic of keratin filaments of certain epithelial cell lines.

Limited tryptic digestion of recombinant human interleukin-2: structure-binding relationships with the alpha chain of the interleukin-2 receptor

The surface topography and structural features of interleukin-2 (IL-2) in relation to its interaction with the alpha subunit of its receptor (IL-2R alpha) have been probed by limited tryptic digestion followed by detailed structural analyses. Four sensitive cleavage sites in IL-2 (Lys8, Lys9, Lys35, and Arg38) were identified as surface amino acids, suggesting that they are potential binding sites for IL-2R alpha. To examine the involvement of these residues in IL-2R alpha binding, a truncated IL-2 molecule lacking the amino-terminal residues through Arg38 was generated and it was found to be incapable of binding IL-2R alpha in a solid-phase receptor binding sequencing assay. These studies have led to the conclusion that the IL-2R alpha contact region of IL-2 includes residues Lys35 and Arg38. This finding is supported by the refined three-dimensional structure of IL-2 in which these residues are located outside of the compact bundle of four helices and thus are readily available for interaction with IL-2R alpha.

A simple technique for harvesting standardized skin grafts in the rodent

A simple technique for harvesting skin grafts of predetermined size, shape, and thickness in rodents is described. In this technique, the donor skin is immobilized and tensed by means of a tongue depressor, or similar template, inserted into the loose areolar tissue below the panniculus, stretching the overlying skin to permit easy dermatome harvesting of a skin graft.

Endothelial monocyte-activating polypeptide II. A novel tumor-derived polypeptide that activates host-response mechanisms

An important means by which tumor cells influence the vasculature is through the production of soluble mediators altering vascular properties. A approximately 22-kDa polypeptide was purified to homogeneity from conditioned medium of murine methylcholanthrene A (meth A) fibrosarcoma cells by ion-exchange chromatography and preparative sodium dodecyl sulfate-polyacryl-amide gel electrophoresis (SDS-PAGE), based on its ability to induce tissue factor procoagulant activity in endothelial cells (ECs). The final product migrated as a broad band on reduced and nonreduced SDS-PAGE and had an unique amino-terminal sequence. This meth A-derived polypeptide modulated EC coagulant properties through the induction of tissue factor, induced monocyte migration and tissue factor expression, and was also chemotactic for granulocytes. Injection of the polypeptide into mouse footpads resulted in an inflammatory response with tissue swelling and polymorphonuclear leukocyte infiltration. The ability of this mediator to activate ECs and monocytes has led us to name it EMAP II (endothelial monocyte-activating polypeptide). EMAP II is distinct from a previously described approximately 40-kDa meth A-derived polypeptide termed EMAP I. Through its potential to activate host effector mechanisms, EMAP II could contribute to the biology of immunogenic tumors, such as the meth A fibrosarcoma.