Diagnostic accuracy of a prehospital electrocardiogram rule-based algorithm for ST-elevation myocardial infarction: results from a population-wide project.

INTRODUCTION: This study reviewed the diagnostic accuracy of the prehospital electrocardiogram (PHECG) rule-based algorithm for ST-elevation myocardial infarction (STEMI) universally utilised in Hong Kong. METHODS: This prospective observational study was linked to a population-wide project. We analysed 2210 PHECGs performed on patients who presented to the emergency medical service (EMS) with chest pain from 1 October to 31 December 2021. The diagnostic accuracy of the adopted rulebased algorithm, the Hannover Electrocardiogram System, was evaluated using the adjudicated blinded rating by two investigators as the primary reference standard. Diagnostic accuracy was also evaluated using the attending emergency physician's diagnosis and the diagnosis on hospital discharge as secondary reference standards. RESULTS: The prevalence of STEMI was 5.1% (95% confidence interval [CI]=4.2%-6.1%). Using the adjudicated blinded rating by investigators as the reference standard, the rule-based PHECG algorithm had a sensitivity of 94.6% (95% CI=88.2%-97.8%), specificity of 87.9% (95% CI=86.4%-89.2%), positive predictive value of 29.4% (95% CI=24.8%-34.4%), and negative predictive value of 99.7% (95% CI=99.3%-99.9%) [all P<0.05]. CONCLUSION: The rule-based PHECG algorithm that is widely used in Hong Kong demonstrated high sensitivity and fair specificity for the diagnosis of STEMI.

[Therapeutic effects of sacral neuromodulation on detrusor underactivity].

OBJECTIVE: To evaluate the effects of sacral neuromodulation (SNM) on detrusor underactivity (DUA). METHODS: From December 2019 to April 2020, 6 patients with DUA who had been treated with SNM were assessed retrospectively. The average age was 58 years (46-65 years), with 3 males and 3 females. All the patients were diagnosed with DUA by urodynamics examination. Obstruction of bladder outlet was excluded through the cystoscopy. No patient had the history of neurological disease. All the patients were placed with the bladder colostomy tube before SNM. One female patient accepted the trans-urethral resection of bladder neck. Two male patients accepted the trans-urethral resection of prostate. All the 3 patients had no improvement of void symptom after the urethral operation. Before SNM, the average 24 h times of voiding was 23.8 (18-33), average volume of every voiding was 34.2 mL (10-50 mL), average residual volume was 421.7 mL (350-520 mL). The preoperative and postoperative 24 h urine frequency, average voided volume, and average residual urine volume were compared respectively. RESULTS: Totally 6 patients underwent SNM with stage Ⅰ procedure. The operation time for stage Ⅰ procedure was 62-135 min (average 90 min). After an average follow-up of two weeks, stage Ⅱ procedure was performed on responders. Four patients accepted stage Ⅱ procedure (conversion rate 66.7%), the other two patients refused the stage Ⅱ procedure because the urine frequency did not reach the satisfied level. But all the patients had the improvement of residual urine volume. For the 4 patients at the follow-up of 10-15 months, the improvement of void was still obvious. For the all patients after stage Ⅰ procedure, the average 24 h urine frequency reduced to 13.5 times (9-18 times, P < 0.001), the average voided volume increased to 192.5 mL (150-255 mL, P < 0.001), and the average residual urine volume reduced to 97.5 mL (60-145 mL, P < 0.001). No adverse events, such as wound infection or electrode translocation were detected during an average follow-up of 11.3 months. Only one of the 4 patients who received the stage Ⅱ procedure did the intermittent catheterization for one time each day. CONCLUSION: SNM provides a minimal invasive approach for the management of DUA.

[Modified posteromedial approach via lateral side of flexor hallucis longus for the treatment of posterior Pilon fracture].

Objective: To compare the clinical efficacy and the level of muscle and soft tissue damage between modified posteromedial approach via lateral side of flexor hallucis longus and modified posteromedial approach in the treatment of posterior Pilon fracture. Methods: Total of 43 patients (27 males and 16 females, aged from 19 to 71 years) diagnosed with posterior Pilon fracture from June 2016 to June 2018 in Foshan Hospital of Traditional Chinese Medicine were randomly divided into observation group (modified posteromedial approach via lateral side of flexor hallucis longus, 21 cases) and control group (modified posteromedial approach, 22 cases) according to the operation approach. The preoperative waiting time, intraoperative time, intraoperative blood loss, hospitalization time and the complications were recorded and compared between the two groups. The differences of blood creatine kinase (CK), myoglobin (Myo) and C-reactive protein (CRP) at different time points before and after operation were compared between the two groups to elevate the level of muscle and soft tissue damage. The fracture reduction qualities of the two groups were compared by Burwell-Charnley criteria. The differences of fracture healing time, range of motion of metatarsophalangeal joint of the great toe (MTP-ROM), ankle range of motion (Ankle-ROM), American Orthopaedic Foot & Ankle Society (AOFAS) score and visual analogue scale (VAS) score of pain were compared between the two groups at the last follow-up. Results: The observation group and the control group were followed-up for (19±6) months and (16±8) months, respectively; there was no significant difference between the two groups (P>0.05). There were no significant differences in preoperative waiting time, intraoperative blood loss, hospitalization time and fracture healing time between the two groups (all P>0.05). At the last follow-up, there was no significant difference in the MTP-ROM and Ankle-ROM between the two groups (both P>0.05); the AOFAS score of the observation group was 88.2±7.8 and it was 84.5±7.6 in the control group (P>0.05); the VAS score of the observation group was (0.9±1.0) and it was (1.3±0.8) in the control group(P>0.05). Anatomical reduction rate in observation group was higher than that in control group (90.5% vs 81.8%, P>0.05). The operation time in the observation group was (87±16) min and it was (98±11) min in the control group (P<0.05). CK, Myo and CRP were increased in both groups after surgery, but there was no statistical significance between groups at the same time point (all P>0.05). There was no nerve injury in the observation group, while 2 cases (9.0%) of nerve paralysis occurred in the control group. No incision infection and checkrein deformity of the Hallux was found in the two groups. Conclusion: The modified posteromedial approach via lateral side of flexor hallucis longus can obtain good operative field exposure, and does not increase muscle and soft tissue injury, with shorter operative time and fewer complications, without nerve injury and checkrein deformity, it is a safe approach for the treatment of posterior Pilon fracture.

[Long-term analysis of safety and efficacy of standard percutaneous nephrolithotomy in patients with solitary kidneys].

OBJECTIVE: To evaluate the long-term efficacy and safety of ultrasound-guided percutaneous nephrolithotomy (PCNL) in the treatment of patients with solitary kidney stones. METHODS: The clinical data of 22 patients with solitary kidney stones treated with PCNL in Peking University People's Hospital from September 2008 to June 2014, with the follow-up data of more than 5 years were analyzed retrospectively. Perioperative indicators, postoperative stone free rate (SFR) and incidence of complications were recorded. Ultrasonography was used to evaluate the long-term stones recurrence rate. Serum creatinine and estimated glomerular filtration rate (eGFR) were used to assess the long-term renal function. RESULTS: In this group of 22 patients, the average age was (50.3±11.8) years, with 10 cases of anatomic solitary kidneys, 12 functional solitary kidneys, and the median stone diameter was 1.65 (1.1-3.9) cm. All the patients had multiple stones, including 7 cases of staghorn stones. The median pre-operative serum creatinine was 104.5 (60.0-460.0) µmol/L, and the mean eGFR was (60.3±29.4) mL/min, showing no statistically significant difference compared with that before surgery. The mean operative time was (88.2±42.0) min, and there were 11 cases of single-channel and double-channel PCNL. The median serum creatinine on the first day after surgery was 102.0 (63.0-364.0) µmol/L, and the mean eGFR was (58.0±25.1) mL/min. The mean postoperative hospital stay was (8.7±5.2) days. In this group, 5 patients (22.7%) presented short-term complications, among which 4 patients presented postoperative infection and massive hemorrhage at the same time, which improved after conservative treatment, and 1 patient presented pleural injury and improved after closed thoracic drainage. Two patients (9.1%) developed long-term complications, and ureteral stricture occurred 3 months after operation, which improved after balloon dilatation. The median follow-up time was 6.2 (4.7-11.1) years. The median serum creatinine at the last follow-up was 104.0 (72.4-377.0) µmol/L, and the mean eGFR was (60.1±23.7) mL/min, showing no statistically significant difference compared with that before surgery. Renal function decreased in 6 patients (27.3%). Initial and final SFR were 72.7% and 100%, respectively. During the 6.2-year follow-up, 9 patients (40.9%) experienced recurrence of kidney stone. After stone recurrence, 13 lithotomy surgeries were performed, and the SFR by the latest follow-up was 63.6%. CONCLUSION: This study had the longest follow-up time for patients with solitary kidney stones after PCNL reported at home and abroad. Ultrasound-guided standard PCNL was safe and effective in the treatment of solitary kidney stones. Long-term follow-up results showed that the recurrence rate of kidney stones was still high, but the long-term renal function was stable after operation, and some patients showed mild renal function decline.

Muscle damage protective effect by two maximal isometric contractions on maximal eccentric exercise of the elbow flexors of the contralateral arm.

Muscle damage after 30 maximal eccentric contractions of the elbow flexors (30MVEC) is reduced when the same exercise is performed by the opposite arm, and when two maximal voluntary isometric contractions at a long muscle length (2MVIC) are performed prior to 30MVEC by the same arm. This study investigated the hypothesis that 2MVIC would attenuate muscle damage after 30MVEC performed by the opposite arm. Untrained young (20-25 years) men were placed into 1 of 4 experimental groups that performed 2MVIC at 1 (1d), 2 (2d), 4 (4d), or 7 days (7d) before 30MVEC by the opposite arm, or one control group that performed 30MVEC only (n = 13/group). Changes in indirect muscle damage markers after 30MVEC were compared among the groups by mixed-design two-way ANOVA. Maximal voluntary concentric contraction torque, range of motion, plasma creatine kinase activity, and muscle soreness did not change significantly after 2MVIC. Changes in these variables after 30MVEC were smaller (P < .05) for 1d (eg, peak soreness: 45 ± 21 mm) and 2d groups (46 ± 20 mm) than control group (66 ± 18 mm), without significant differences between 1d and 2d groups. No significant differences in the changes were found among 4d, 7d, and control groups, except for soreness showing smaller (P < .05) increases for 4d group (54 ± 19 mm) than 7d (62 ± 17 mm) and control groups. These results supported the hypothesis and showed that muscle damage induced by 30MVEC was reduced by 2MVIC performed 1-2 days prior to 30MVIC by the contralateral arm.

Safety and efficacy of oral febuxostat for treatment of HLA-B*5801-negative gout: a randomized, open-label, multicentre, allopurinol-controlled study.

OBJECTIVES: This phase IIIB study compared the efficacy and safety of febuxostat and allopurinol in gout patients with or without tophi who were HLA-B*5801 negative. METHOD: Eligible patients were randomized to a febuxostat group (80 mg QD) or an allopurinol group (300 mg QD). Following an initial 2-week washout period, over the next 12 weeks we made five measurements of serum urate levels along with assessments of adverse events (AEs). RESULTS: Forty-three out of 152 screened subjects (28.3%) were ineligible either because of the presence of the HLA-B*5801 allele or for various other reasons. The febuxostat group (n = 54) and the allopurinol group (n = 55) had no significant differences in demographic or baseline characteristics. From week 2 to week 12, the febuxostat group had a significantly lower serum urate level than the allopurinol group (p ≤ 0.001 for all comparisons) and significantly more patients with serum urate levels less than 6.0 mg/dL. The serum urate levels of the febuxostat group declined by more than 40% from week 2 to week 12 and this decrease was greater than that in the allopurinol group (~30%). The two groups were similar in terms of AEs. CONCLUSIONS: Febuxostat was more effective than allopurinol in reducing the serum urate levels of Han Chinese patients with gout or tophaceous gout who were HLA-B*5801 negative, without causing any serious skin reactions. Febuxostat should be considered for treatment of Han Chinese patients with gout who are HLA-B*5801 negative.

Structure and polymorphism of novel X-chromosome short tandem repeat loci in a Chinese Han population.

Recently, 5 novel X-chromosome short tandem repeat (X-STR) loci with high degrees of polymorphism were examined. In this study, we investigated the genetic distribution of these loci in a Chinese Han population. The 5 X-STR loci were successfully examined by polyacrylamide gel electrophoresis in a total of 200 unrelated Shaanxi Han individuals (100 males and 100 females). Hardy-Weinberg equilibrium tests revealed no significant deviation from expected values (P > 0.05) for all 5 X-STR loci in the Shaanxi Han population.The loci were named DXS-p11.3, DXS-q12, DXS-q13.3, DXS-q22.1, and DXS-q25 and were found to contain 6, 8, 7, 7, and 5 alleles, respectively. In addition, 17, 21, 18, 19, and 11 genotypes, respectively, were detected in the female samples. The heterozygosities of the 5 X-STR loci were 0.75, 0.74, 0.74, 0.72, and 0.56, respectively. The polymorphic information contents of the 5 X-STR loci were 0.70, 0.69, 0.69, 0.68, and 0.51, respectively. The individual discrimination values of the 5 X-STR loci were 0.88, 0.86, 0.88, 0.87, and 0.74, respectively. Five new X-chromosome STR loci with high degrees of polymorphism were observed in our lab. The results of this study are important for forensic individual identification, paternity identification, and population genetics research.

Dopamine receptor D1 but not D3 essential for morphine-induced conditioned responses.

Recent studies indicate the involvement of dopamine receptors D1 and D3 in the regulation of locomotor stimulant and conditioned responses to morphine in mice. Moreover, expression of brain-derived neurotrophic factor (BDNF) may be modulated by D1 and D3 receptor activities in the nucleus accumbens (NAc) and prefrontal cortex (PFC). However, the underlying interactions between D1 and D3 receptors and BDNF in the expression of behavioral responses controlled by drug-associated cues have not yet been fully elucidated. In this study, we used dopamine receptor mutant mice to explore the roles of the D1 and D3 receptors in locomotion and morphine-induced place preference; furthermore, we investigated the effects of morphine on BDNF expression in the NAc and PFC of the mouse brain. Our results show that D1 receptor but not D3 receptor mutant mice had decreased sensitivity to acute morphine-induced (10 mg/kg) locomotion (D1: 3814.82 ± 319.9 cm vs D3: 8089.64 ± 967.4 cm). Furthermore, D1 receptor mutant mice did not acquire morphine-conditioned place preference (D1: -18.3 ± 59.9, D3: 217.7 ± 64.1) and showed decreased BDNF expression in the NAc (D1: 0.33 ± 0.07 fold, D3: 2.21 ± 0.18 fold) and PFC (D1: 0.74 ± 0.15 fold, D3: 1.68 ± 0.22 fold) compared with wild-type and D3 receptor mutant mice. These findings suggest that the D1 receptor is necessary for the induction of cue-associated morphine seeking and modulates locomotor habituation processes in response to acute morphine. The dopamine receptor D1 but not the D3 is also critical for morphine-induced BDNF expression in the NAc and PFC.

Laparoscopic surgery for colorectal cancer.

BACKGROUND: Laparoscopic surgery for colorectal cancer has undergone tremendous advancement in the last two decades, with maturation of techniques and integration into current practice. SOURCES OF DATA: Worldwide English-language literature on laparoscopic surgery for the management of colon and rectal cancer was reviewed. AREAS OF AGREEMENT: A large body of evidence has attested to the improved short-term outcomes and long-term oncological safety of laparoscopic surgery for colon cancer. Laparoscopic colectomy can be recommended to suitable patients where expertise is available. Laparoscopic resection for rectal cancer is feasible, with good evidence of faster post-operative recovery and adequate surgical quality, but requires more data on long-term oncological outcomes. This review examines the evidence and current practice of laparoscopic surgery for colorectal cancer. AREAS OF CONTROVERSY: Does laparoscopic surgery confer a survival advantage for colorectal cancer patients? GROWING POINTS: The role of single-incision laparoscopic surgery and robotic surgery in colorectal cancer. AREAS TIMELY FOR DEVELOPING RESEARCH: Barriers to the adoption of the laparoscopic technique.

Nine polymorphic STR loci in the HLA region in the Shaanxi Han population of China.

A large number of microsatellite genetic markers have been identified in the human leukocyte antigen (HLA) region. We investigated genetic polymorphism of the nine short tandem repeat (STR) loci (D6S276, MOGCA, D6S265, MIB, D6S273, G51152, TAP1CA, RING3CA, and D6S291) in the HLA region in the Shaanxi Han population. Using a fluorescence-labeled multiplex-PCR STR typing method, 6-13 alleles were detected in these nine STR loci in 150 unrelated Han Chinese from the region of Shaanxi, China. The distributions of the genotypes at these nine loci were in Hardy-Weinberg equilibrium. We conclude that these nine STR loci have a high level of genetic polymorphism; they would be useful for population genetic studies, pre-transplantation HLA typing, forensic and paternity testing, etc.

Polymorphism G861C of 5-HT receptor subtype 1B is associated with heroin dependence in Han Chinese.

The serotoninergic (5-HT) system regulates neuronal activity in broad brain regions, and appears to be particularly important for modulating behavioral and physiological functions such as mood, emotion, sleep and appetite. Central 5-HT deregulation may be involved in many neuropsychological disorders, which include substance abuse and addiction. Previous studies suggest that genetic polymorphisms in some 5-HT receptor genes may relate to heroin dependency. Here we examined potential association between heroin dependence and four single nucleotide polymorphisms (SNPs) of 5-HT receptors (A-1438G and T102C of HTR(2A), and G861C and A1180G of HTR(1B)) in a cohort of Han Chinese. Participants included 303 heroin-dependent subjects who were recruited into the Methadone Maintenance Treatment (MMT) Program in the Xi'an Mental Health Center, and 300 healthy controls. The resulting data yielded a significantly higher frequency of the HTR(1B) G allele with G861C among the heroin-dependent subjects relative to controls (p=0.001 after Bonferroni correction). Further genotype and clinical phenotype correlation study of the G861C carriers showed that the amount of heroin self-injection was higher in patients with the GG genotype relative to CC and CG genotypes (p<0.01). These findings point to a role for HTR(1B) polymorphism in heroin dependence among Han Chinese, and may be informative for future genetic or neurobiological studies on heroin dependence.

A study on the relationship between TCTA tetranucleotide polymorphism of the HPRT gene and primary hyperuricemia.

We examined polymorphism of the TCTA tetranucleotide sequence in the 3rd intron of the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene in the Han population of Ningxia Province in China. We also looked for a possible relationship between STR polymorphism in the 3rd intron of the HPRT gene and primary hyperuricemia. We used Chelex-100 to extract DNA, then PCR, PAGE and silver staining for allele genotyping and DNA sequencing to obtain the distribution of the alleles. We found, for the first time, that there is high STR polymorphism in the 3rd intron of the HPRT gene. We detected 5 STR alleles in this intron in the Han population of Ningxia Province, with 15 genotypes in females; significant differences were observed in the distribution of alleles and genotypes between control and patient groups for both males and females. Alleles of the TCTA repeat in the 3rd intron of the HPRT gene were found to be associated with primary hyperuricemia; consequently, these alleles may be considered risk factors for primary hyperuricemia.

Meniscus and cartilage exhibit distinct intra-tissue strain distributions under unconfined compression.

OBJECTIVE: To examine the functional behavior of the surface layer of the meniscus by investigating depth-varying compressive strains during unconfined compression. DESIGN: Pairs of meniscus and articular cartilage explants (n=12) site-matched at the tibial surfaces were subjected to equilibrium unconfined compression at 5, 10, 15, and 20% compression under fluorescence imaging. Two-dimensional (2D) deformations were tracked using digital image correlation (DIC). For each specimen, local compressive engineering strains were determined in 200 µm layers through the depth of the tissue. In samples with sharp strain transitions, bilinear regressions were used to characterize the surface and interior tissue compressive responses. RESULTS: Meniscus and cartilage exhibited distinct depth-dependent strain profiles during unconfined compression. All cartilage explants had elevated compressive engineering strains near the surface, consistent with previous reports. In contrast, half of the meniscus explants tested had substantially stiffer surface layers, as indicated by surface engineering strains that were ∼20% of the applied compression. In the remaining samples, surface and interior engineering strains were comparable. 2D Green's strain maps revealed highly heterogeneous compressive and shear strains throughout the meniscus explants. In cartilage, the maximum shear strain appeared to be localized at 100-250 µm beneath the articular surface. CONCLUSIONS: Meniscus was characterized by highly heterogeneous strains during compression. In contrast to cartilage, which consistently had a compliant surface region, meniscal explants were either substantially stiffer near the surface or had comparable compressive stiffness through the depth. The relatively compliant interior may allow the meniscus to maintain a consistent surface contour while deforming during physiologic loading.

Distribution of human leukocyte antigen alleles and haplotypes in Oroqen and Ewenki nationality minority in Inner Mongolia Autonomous Region of China.

The frequencies of the human leukocyte antigen alleles HLA-A,-B, DRB1 and the A-B, A-DRB1, B-DRB1, A-B-DRB1 haplotypes were investigated through means of PCR-based reverse line-strip sequence specific oligonucleotide hybridization on 108 Oroqen and 104 Ewenki nationality unrelated healthy individuals from the Inner Mongolia Autonomous Region of China. A total of thirteen different HLA-A alleles, 21 different HLA-B alleles and 13 different HLA-DRB1 alleles were detected in the Oroqen ethnic group and the most frequent HLA alleles found were A*24(35.65%), B*15(17.92%), and DRB1*09(17.59%), respectively. The common HLA-A-B-DRB1 haplotypes were A*24-B*40-DRB1*09(5.09%), A*24-B*48-DRB1*12(2.78%) and A*24-B*51-DRB1*04(2.78%); and the HLA-A*33-B*58, A*30-B*13, A*01-B*37, A*33-DRB1*03, A*01-DRB1*10, A*30-DRB1*07, B*37-DRB1*10, B*58-DRB1*03, B*38-DRB1*08, B*13-DRB1*07 were significant positive linkage disequilibrium in the Oroqen nationality group. In total, 14 different HLA-A alleles, 27 B alleles and 12 DRB1 alleles were found in Ewenki nationality group, and the most frequent HLA alleles found were A*24(24.49%), B*40(17.35%), and DRB1*04(14.80%), respectively. The common HLA-A-B-DRB1 haplotypes were A*33-B*58-DRB1*03(6.25%), A*01-B*51-DRB1*11(2.88%) and A*24-B*40-DRB1*09(2.88%); the HLA-A*33-B*58, A*29-B*44, A*03-B*52, A*33-DRB1*03, A*29-DRB1*07, A*24-DRB1*09, B*58-DRB1*03, B*08-DRB1*03, B*46-DRB1*09 were significant positive linkage disequilibrium in Ewenki nationality group. The distribution of HLA A,-B, DRB1, alleles haplotypes frequencies and phylogenetic tree indicated that the Oroqen and Ewenki population groups belongs to northern group of China, together as a group cluster.

Genetic susceptibility to haemorrhagic fever with renal syndrome caused by Hantaan virus in Chinese Han population.

We report a significantly higher occurrence of HLA-DRB1*09 (51% vs. 23%, P = 0.002, OR = 3.57) and HLA-B*46-DRB1*09 (26% vs. 8%, P = 0.018, OR = 3.76) in patients with haemorrhagic fever with renal syndrome (HFRS) compared to the control group, suggesting Hantaan virus-induced HFRS is associated with a genetic predisposition in the Chinese Han population.

RelA is a potent transcriptional activator of the CD28 response element within the interleukin 2 promoter.

T-cell activation requires two different signals. The T-cell receptor's recognition of a specific antigen on antigen-presenting cells provides one, and the second signal comes from costimulatory molecules such as CD28. In contrast, T cells that are stimulated with antigen in the absence of the CD28 costimulatory signal can become anergic (nonresponsive). The CD28 response element (CD28RE) has been identified as the DNA element mediating interleukin 2 (IL-2) gene activation by CD28 costimulation. Our previous work demonstrates that the Rel/NF-kappa B family proteins c-Rel, RelA (p65), and NFKB1 (p50) are involved in the complex that binds to the CD28RE. We also showed that c-Rel, but not NFKB1 (p50), can bind to the CD28RE and activate CD28RE-driven transcription in cotransfection assays. However, the role of RelA (p65) in CD28 signaling has not yet been addressed. We provide evidence that RelA (p65) itself bound directly to the CD28RE of the IL-2 promoter and other lymphokine promoters. In addition, RelA (p65) was a potent transcriptional activator of the CD28RE in vivo. We show that a RelA (p65)-c-Rel heterodimer bound to the CD28RE and synergistically activated the CD28RE enhancer activity. We also demonstrate that activated Raf-1 kinase synergized with RelA (p65) in activating the CD28RE enhancer activity. Interestingly, a soluble anti-CD28 monoclonal antibody alone, in the absence of other stimuli, also synergized with RelA (p65) in activating the CD28RE. Furthermore, we show that RelA (p65) activated expression of the wild-type IL-2 promoter but not the CD28RE-mutated IL-2 promoter. A combination of RelA (p65) and NFKB1 (p50) also activated the IL-2 promoter through the CD28RE site. These results demonstrate the functional regulation of the CD28RE, within the IL-2 promoter, by Rel/NF-kappa B transcription factors.

Effect of CD28 signal transduction on c-Rel in human peripheral blood T cells.

Optimal T-cell activation requires both an antigen-specific signal delivered through the T-cell receptor and a costimulatory signal which can be delivered through the CD28 molecule. CD28 costimulation induces the expression of multiple lymphokines, including interleukin 2 (IL-2). Because the c-Rel transcription factor bound to and activated the CD28 response element within the IL-2 promoter, we focused our study on the mechanism of CD28-mediated regulation of c-Rel in human peripheral blood T cells. We showed that CD28 costimulation accelerated the kinetics of nuclear translocation of c-Rel (and its phosphorylated form), p50 (NFKB1), and p65 (RelA). The enhanced nuclear translocation of c-Rel correlated with the stimulation of Il-2 production and T-cell proliferation by several distinct anti-CD28 monoclonal antibodies. This is explained at least in part by the long-term downregulation of I kappa B alpha following CD28 signalling as opposed to phorbol myristate acetate alone. Furthermore, we showed that the c-Rel-containing CD28-responsive complex is enhanced by, but not specific to, CD28 costimulation. Our results indicate that c-Rel is one of the transcription factors targeted by CD28 signalling.

Usefulness of human leucocyte antigen-B27 subtypes in predicting ankylosing spondylitis: Taiwan experience.

BACKGROUND: Genetic factors are clearly attributed to the susceptibility of ankylosing spondylitis (AS). The human leucocyte antigen (HLA)-B27 proved to be the very useful marker for diagnosing AS. The aim of this study was to determine the prevalence of HLA-B27 subtypes in Taiwan and to investigate whether these subtypes may be of help in predicting the diagnosis of AS. METHODS: A total of 314 patients with AS and a control group of 71 subjects positive for HLA-B27 detected by flow cytometry analysis were recruited for the study. HLA-B27 subtypes were confirmed by the polymerase chain reaction-sequence-specific primers and sequence-specific oligonucleotide probing. RESULTS: Four B27 alleles were identified: B*2704, B*2705, B*2706 and B*2707. HLA-B*2704 was the predominant allele. There were significant differences in the distribution of HLA-B27 subtypes between patients with AS and controls. Five of them who were homozygous for the B*2704 allele were solely found in AS group but not in controls. Statistical analysis showed that B*2704 was positively associated with AS, which suggested an increased possibility of having AS. Other HLA-B27 subtypes showed no strong correlation with AS. CONCLUSION: In the Taiwanese population, susceptibility to AS was determined by the presence of HLA-B*2704. Although B*2706 was reported to have a negative association with AS in Taiwanese, Thai and Chinese Singaporean populations, we report, in our study, two AS patients with B*2706 (0.6%). Disease heterogeneity suggests that other than genetic background, many pathogenic factors could be associated with AS. This may need to be investigated with a larger group of patients with AS and controls.

Plant alkaloid tetrandrine and its analog block CD28-costimulated activities of human peripheral blood T cells: potential immunosuppressants in transplantation immunology.

BACKGROUND: T lymphocyte activation mediated by CD28 costimulation plays a critical role in graft rejection. Plant alkaloid tetrandrine, purified from a Chinese antirheumatic herb, is a potent immunosuppressant. Here, we examined its effects on several CD28-costimulated T-cell activities. In addition, such effects were readily compared with the effects of three tetrandrine analogs. METHODS: T lymphocytes were purified from whole blood by negative selection. The stimuli that mimic CD28 costimulation included both anti-CD3 + anti-CD28 monoclonal antibody and PMA+anti-CD28 monoclonal antibody. The determination of CD28-costimulated cell proliferation was performed by tritium uptake, cytokine production by ELISA, cell surface interleukin 2Ra and CD69 expression by flow cytometry, and mixed leukocyte reaction by tritium uptake. Drug cytotoxicity was determined by trypan blue exclusion, propidium iodide staining, and MTT colorimetric assays. RESULTS: Tetrandrine inhibited CD28-costimulated T-cell proliferation and cytokine production through a mechanism different from that of cyclosporine. In addition, tetrandrine down-regulated both T helper 1 and T helper 2 cytokine production in CD4+ and CD8+ T-cell subpopulations. By examining cytokine production and T-cell activation marker expression, we further demonstrated that, among tetrandrine and its analogs tested, dauricine was the most potent suppressor of CD28-costimulated T-cell activities. Furthermore, the different immunosuppressive activities of these compounds were not associated with their cytotoxic capacities. Finally, the unparalleled inhibitory potency of dauricine on both mixed leukocyte reaction and CD28-costimulated T-cell proliferation suggests that dauricine preferentially targeted CD28-costimulated T-cell activities. CONCLUSIONS: This is the first report to show that tetrandrine and its analogs potently inhibited both PMA+CD28-costimulated and CD3 + CD28-costimulated activation of human peripheral blood T cells. Based upon their structural similarity and different immunosuppressive potency, these in vitro data also provide very useful information for further identification and development of more potent and less toxic immunosuppressants to achieve transplantation success.