[Analysis on incidence of occupational diseases in Guangzhou from 2010 to 2020].

Objective: To analyze the incidence characteristics of occupational diseases in Guangzhou from 2010 to 2020, provide scientific basis for formulating occupational disease prevention and control policies. Methods: In January 2021, based on the data of occupational diseases in Guangzhou reported in the Information Monitoring System of Occupational Diseases and Occupational Health, descriptive epidemiological method was used to analyze the types and characteristics of occupational diseases in Guangzhou from 2010 to 2020. Results: A total of 1341 cases of 38 kinds of occupational diseases in 9 categories were reported in the past 11 years. The incidence of occupational pneumoconiosis, occupational otolaryngology and oral diseases and occupational chemical poisoning ranked the top three, accounting for 38.1% (511/1341) , 30.5% (409/1341) and 16.2% (217/1341) of the total cases respectively. The cases of pneumoconiosis in welders and silicosis accounted for 47.7% (244/511) and 34.4% (176/511) of the cases of occupational pneumoconiosis respectively. The cases of noise deafness accounted for 99.8% (408/409) of occupational otorhinolaryngology oral diseases. Acute occupational chemical poisoning cases accounted for 26.7% (58/217) of the occupational chemical poisoning cases, in which dichloroethane poisoning cases ranked the first, accounting for 79.3% (46/58) . Chronic occupational chemical poisoning cases accounted for 73.3% (159/217) of the occupational poisoning cases, in which benzene and lead poisoning cases ranked the top two, accounting for 79.2% (126/159) and 17.6% (28/159) respectively. Conclusion: Pneumoconiosis, silicosis, noise deafness, benzene poisoning, lead poisoning, dichloroethane poisoning should be supervised and managed as key occupational diseases in Guangzhou.

TGIF2 promotes cervical cancer metastasis by negatively regulating FCMR.

OBJECTIVE: We aimed at studying the correlation between TGIF2 expression and clinicopathological features of cervical cancer (CCa). The relationship between TGIF2 and FCMR and its influence on the proliferation and metastasis of tumor cells were investigated using molecular biology techniques, so as to reveal the pathogenesis of CCa and provide a new target for clinical treatment. PATIENTS AND METHODS: TGIF2 expression in 60 pairs of cervical tumors and paracancerous tissues samples collected from CCa patients of our hospital was studied by quantitative real-time polymerase chain reaction (qPCR) analysis, and the association between TGIF2 expression and the clinical indicators or prognosis of CCa patients were analyzed. CCa cells with TGIF2 knockdown were constructed using transfection technology. Changes in the biological phenotypes (proliferation, migration, invasion) of CCa cells C33-A and HeLa after TGIF2 knockdown were determined by Cell Counting Kit-8 (CCK-8) and transwell assays. In addition, the effects of TGIF2/FCMR axis on CCa metastasis were further explored in nude mice in vivo. RESULTS: Our data revealed a significant increase in TGIF2 mRNA expression in CCa tissue specimens compared to adjacent ones, and the increasing degree was positively correlated with the incidence of lymph node or distant metastasis of CCa patients. The results of CCK-8 and transwell suggested that knocking down TGIF2 effectively attenuated the proliferative ability and invasiveness of CCa cells. Luciferase assay confirmed that TGIF2 can directly bind to the DNA promoter of its target gene FCMR. Simultaneous transfection of sh-TGIF2 and sh-FCMR partially reversed the inhibitory effect of single transfection of TGIF2 knockdown on the malignant progression of CCa. Experiments in nude mice also suggested that TGIF2 could promote CCa tumorigenesis through the modulation of FCMR expression. CONCLUSIONS: In summary, TGIF2 can promote the migration and proliferation ability of cervical cancer cells via down-regulating FCMR. Our study provides a new therapeutic target for the clinical treatment of cervical cancer.

Long noncoding RNA ZFAS1 promotes hepatocellular carcinoma proliferation by epigenetically repressing miR-193a-3p.

OBJECTIVE: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Long noncoding RNAs (lncRNAs) play important roles in many diseases. Therefore, the aim of this study was to investigate the role of lncRNA ZFAS1 in the development of HCC and to explore its underlying mechanism. PATIENTS AND METHODS: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was utilized to detect ZFAS1 expression in tissue samples of HCC patients. Subsequently, Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and EdU incorporation assay were performed to detect the function of ZFAS1 in vitro. Furthermore, mechanism assays were performed to explore the interaction between ZFAS1 and miR-193a-3p. RESULTS: ZFAS1 was significantly highly expressed in HCC tissues than that of adjacent normal tissues. The growth ability of HCC cells was markedly inhibited after ZFAS1 was silenced. However, the growth ability of HCC cells was remarkably promoted after ZFAS1 overexpression. Moreover, RT-qPCR results revealed that miR-193a-3p was significantly down-regulated via the overexpression of ZFAS1. However, miR-193a-3p was significantly up-regulated via the knockdown of ZFAS1. Further experiments showed that miR-193a-3p was a direct target of ZFAS1 in HCC. CONCLUSIONS: ZFAS1 could enhance the proliferation of HCC cells by suppressing miR-193a-3p, which might be a potential therapeutic target in HCC.

[Analysis of the cardiovascular effects on workers expose to occupational benzene-toluene-xylene and noise in a painting workshop of an automobile company].

Objective: To learn about the cardiovascular health effects of workers expose to benzene-toluene-xylene and noise in painting workshop of automobile manufacturing enterprises, and to provide intervention measures and strategies for the health of workers. Methods: The effects of noise exposure, benzene-toluene-xylene exposure and combined exposure on workers' blood pressure and electrocardiogram were analyzed through epidemiological investigation, workplace monitoring and occupational health examination in several automobile enterprises which had carried out occupational hazard factors monitoring and occupational health examination in our hospital from April to October 2017. Results: There were differences in age, sex, working years, smoking, drinking and physical exercise among workers in different exposure groups (P<0.05) . The systolic blood pressure level of workers in benzene-toluene-xylene exposure group and combined exposure group was significantly different comparing with control group (P< 0.05) , After the factors of age and working years were adjusted. The abnormity rate of electrocardiogram in workers were not statistically significant in all groups (P>0.05) . Conclusion: The benzene-toluene-xylene exposure and noise combined with benzene-toluene-xylene exposure in painting workshop of automobile manufacturing enterprises has positive influence on the systolic blood pressure of workers. Regular physical examination and health intervention measures should be strengthened to improve health.

Visualising the boundary sharpness of uterine zonal structures using high-resolution T2-weighted images during the menstrual cycle.

AIM: To investigate whether there is an optimal time in the menstrual cycle to obtain the best image quality of uterine zonal structures with high-field magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-eight normal volunteers with regular menstrual cycles underwent pelvic 3 T high-resolution T2-weighted three-dimensional (3D) turbo spin echo (TSE) with variable flip angle MRI examinations during the menstrual phase (MP), follicular phase (FP), peri-ovulatory phase (OP), and luteal phase (LP). Two radiologists blinded evaluated the boundary sharpness of the three zonal structures of the uterine corpus and cervix on mid-sagittal images using a three-point Likert-scale. The signal intensity (SI) on T2-weighted sequences of each zonal structure was measured and the ratio between the SI of adjacent structures was calculated. Paired Wilcoxon's test and repeated measurement analysis of variance were used to investigate the differences among the four phases. RESULTS: No variation during the menstrual cycle was found in 10.5% (4/38) of volunteers and their boundaries were all well-defined. The OP exhibited the clearest boundaries of the corpus zonal structures. For the endometrium to junctional zone, mean scores of boundary sharpness from high to low were 3 (OP), 2.97 (FP), 2.76 (LP), 2.74 (MP); that for the junctional zone to myometrium were 2.76 (OP), 2.42 (FP), 2.32 (LP), 2.11 (MP); which were consistent with the SI ratio results. The results for the cervix showed no statistical difference during the menstrual cycle (p>0.05), and was well-defined throughout. CONCLUSIONS: The OP is recommended as the best phase to investigate zonal-related uterine corpus diseases due to the best contrast. For cervical diseases, imaging could be performed when necessary at any time point, due to the limited influence of menstrual phases on cervical zone delineation.

[Retrospective analysis of factors affecting patency rates and causes of failure in use of single-armed two-suture microsurgical vasoepididymostomy].

Objectives: To analyze the factors affecting the patency rate of microsurgical single-stitch longitudinal intussusception vasoepididymostomy and to explore the possible causes of failure. Methods: The clinical data of 87 patients with epididymal obstructive azoospermia who underwent microsurgical vasoepididymostomy from January 2015 to February 2018 in the First Affiliated Hospital of Fujian Medical University were analyzed retrospectively. We observed the patency rate postoperatively and evaluated several factors that possibly related to the patency rates. Preoperative examinations included peripheral blood chromosomes, Y chromosome microdeletions, sex hormones, seminal plasma, etc. After admission, microsurgical single-stitch longitudinal intussusception vasoepididymostomy was performed. During the follow-up, the semen was evaluated to assess the patency rate and the time to patency. Results: The patient's age ranged from 21 to 42 years and the mean age was(25±3) years. Infertility lasted for 1-8 years and the mean infertility time was(2.2±1.1) years. The longitudinal intussusception vasoepididymostomy was successfully completed in 80 patients , 5 cases gave up the anastomosis surgery because of multiple segment obstruction of the vas deferens, complete obstruction of the epididymis or testicular obstruction. Two cases underwent crossed vasovasostomy( sperm was present in the ejaculate in 1 case postoperatively). Of all the patients, 72 were successfully followed up. The follow-up time was 3-29 months, with an average of (12.0±1.7)months. Excluding 3 cases of follow-up time less than 12 months who still had no sperm in the ejaculate, 69 patients' data were in cluded in the final statistics, of which 50 cases with return of sperm in the ejaculate, the overall patency rate was 72.5%(50/69), concentration of sperm was 0.1-137.2 million/ml, and the mean concentration was(29±21) million/ml; with the progressive motile sperm rate ranging from 0-57.9%, the mean rate was(29.9±21.1)%. The patency rates of motile sperm and immobile sperm found in epididymal fluid during surgery were 82.2%(37/45) and 54.2%(13/24), respectively. The patency rate of bilateral and unilateral anastomoses was 77.6%(45/58) and 45.5%(5/11), respectively; the patency rate of caput anastomosis was 47.8%(11/23), and 84.8%(39/46) for corpus or caudal anastomosis. 17 patients achieved natural pregnancy postoperatively, the rate was 34.0%(17/50). Conclusions: The therapeutic effect of microsurgical single-stitch longitudinal intussusception vasoepididymostomy is satisfactory. The motile spermatozoa in epididymal fluid, bilateral surgery and corpus or caudal anastomosis can improve the patency rate postoperatively.

[Analysis of the prevalence and related risk factors of prostate diseases in traffic policemen].

Objective: To investigate the prevalence and related risk factors of prostate diseases in traffic policemen. Methods: A total of 848 traffic policemen who took part in the physical examination among August and September in 2016 were selected as research subjects, and a questionnaire survey was conducted to collect their information including smoking, alcohol drinking, biological and physiological indicators, as well as prostate disease etc. The relationship between the prevalence of prostate diseases and related risk factors was analyzed by Non-conditional Logistic Regression. Results: The total prostate disease prevalence rate was 40.2% in the study subjects, and there is statistical significance (P<0.05) of differences between prostate disease group and non disease group in age, work age, smoking, drinking and field work. Single factor analysis showed that age, work age, smoking, and field work are independent risk factors of prostate disease (P<0.05) . Multivariate Logistic regression analysis showed that increasing age (OR 1.03) , smoking (OR 1.92) and field work time (OR 1.47) significantly increased the risk of prostate disease in male police after age, smoking, drinking, BMI, systolic blood pressure, diastolic blood pressure, fasting blood glucose, blood lipids and other indicators were adjusted. Conclusion: age, smoking and field work time are risk factors of prostate diseases in the traffic police. There is great significance in publicizing the harmful effects of smoking and reducing the duration of field work.

[Influence of collagen/fibroin scaffolds containing silver nanoparticles on dermal regeneration of full-thickness skin defect wound in rat].

Objective: To explore the influence of collagen/fibroin scaffolds containing silver nanoparticles on dermal regeneration of full-thickness skin defect wound in rat. Methods: Eighty-one collagen/fibroin scaffolds containing silver nanoparticles (with the mass concentration of silver nanoparticles as 10 mg/L) and 81 collagen/fibroin scaffolds without silver nanoparticles were produced respectively with freeze-drying method and enrolled as silver nanoparticles scaffold group (SNS) and control scaffold group (CS). Nine scaffolds in each group were cultured with human fibroblasts. At post culture hour (PCH) 2, 12, and 24, the human fibroblasts adherent to the scaffolds (n=3) in two groups were counted. Four full-thickness skin defect wounds were reproduced on the back of each one of the 36 SD rats. The rats were divided into groups SNS (wounds were transplanted with collagen/fibroin scaffolds containing silver nanoparticles) and CS (wounds were transplanted with collagen/fibroin scaffolds without silver nanoparticles) according to the random number table, with 18 rats in each group. In post surgery week (PSW) 1, 2, and 4, 6 rats in each group were sacrificed respectively for general observation, observation of histological structure, inflammatory cell infiltration, and collagen deposition with HE staining, count of CD68 positive cells with immunohistochemical staining, and mRNA expressions of interleukin-6 (IL-6) and IL-10 with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction. Results: (1) At PCH 2, 12, and 24, the numbers of human fibroblasts adherent to the scaffolds in the two groups were close (with t values from 1.77 to 2.60, P values above 0.05). (2) In PSW 1, no obvious symptom of infection was observed in wound or wound edge of rats in group SNS with obvious vascularization of scaffolds, while obvious symptoms of infection were observed in wounds of rats in group CS with some scaffolds exfoliated. In PSW 2, the scaffolds were firmly attached to the wounds of rats in group SNS, while obvious contracture was observed in the wounds of rats in group CS with a lot of scaffolds exfoliated. In PSW 4, the scaffolds covered the wounds of rats in group SNS with obvious epithelization on the surface of the scaffolds, while all the scaffolds exfoliated, leaving obvious contracture of residual wounds of rats in group CS. (3) In PSW 1 and 2, compared with those in group CS, more collagen secretion and tissue regeneration and less inflammatory cell infiltration in the scaffolds were observed in the wounds of rats in group SNS. In PSW 4, obvious epithelization was observed in the wounds of rats in group SNS, while inflammatory cell infiltration was observed without obvious epithelization in the wounds of rats in group CS. (4) In PSW 1, the number of CD68 positive cells in the wounds of rats in group SNS [(54±10) /mm(2)] was similar to that in group CS [(78±7) /mm(2,) t=1.52, P>0.05]. In PSW 2 and 4, the numbers of CD68 positive cells in the wounds of rats in group SNS [(154±10) and (77±7) /mm(2)] were significantly less than those in group CS [(268±16) and (136±13) /mm(2,) with t values respectively 7.31 and 3.83, P values below 0.01] respectively. (5) Except for the expression in PSW 4 (t=1.23, P>0.05), the mRNA expressions of IL-6 in the wounds of rats in group SNS in PSW 1 and 2 were significantly lower than those in group CS (with t values respectively 13.12 and 4.65, P values below 0.01). Except for the expression in PSW 1 (t=3.08, P<0.05), the mRNA expressions of IL-10 in PSW 2 and 4 in the wounds of rats in the two groups were similar (with t values respectively 2.14 and 0.49, P values above 0.05). Conclusions: Besides good biocompatibility, collagen/fibroin scaffolds containing silver nanoparticles have obvious effect in modulating inflammation, thus they can accelerate dermal regeneration induced by collagen/fibroin scaffolds for wound repair.

Effects of Piper sarmentosum extract on the growth performance, antioxidant capability and immune response in weaned piglets.

The biological properties of Piper sarmentosum render it a potential substitute for antibiotics in livestock feed. This study evaluated the effects of P. sarmentosum extract (PSE) on the growth performance, antioxidant capability and immune response of weaned piglets. Eighty 21-d-old weaned piglets were selected and randomly allocated to one of four dietary treatments with five replicates of four pigs each. The dietary treatments consisted of a basal diet supplemented with 0 (T0), 50 (T50), 100 (T100) or 200 (T200) mg/kg PSE. The feeding trial lasted 4 weeks. The results revealed that the T50 group had the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the feeding trial (p < 0.05). Additionally, the T50 group had higher (p < 0.05) serum glutathione peroxidase activity (GSH-Px) and lower (p < 0.05) serum malondialdehyde (MDA) levels than the T0 group at 4 weeks post-weaning (p < 0.05). Serum levels of interleukin-1ß (IL-1ß) and tumour necrosis factor-α (TNF-α) decreased, while serum levels of interleukin-4 (IL-4), interleukin-10 (IL-10) and transforming growth factor-ß (TGF-ß) increased by PSE supplementation at 4 weeks post-weaning (p < 0.05). PSE supplementation upregulated the mRNA expression of IL-4, IL-10 and TGF-ß and downregulated the mRNA expression of TNF-α, IL-1ß and interleukin-6 (IL-6) in the ileal mucosal layer of piglets (p < 0.05). In summary, our study findings revealed that PSE supplementation improved the antioxidant capability, and reduced inflammation, which may be beneficial to weaned piglet health.

[Effectiveness of transurethral seminal vesiculoscopy in the treatment of persistent hematospermia, and oligoasthenozoospermia and azoospermia from ejaculatory duct obstruction].

Objective: To analyze the effectiveness of transurethral seminal vesiculoscopy in the treatment of persistent hematospermia, and oligoasthenozoospermia and azoospermia from ejaculatory duct obstruction. Methods: The clinical date of 56 cases of persistent hematospermia, or azoospermia/oligoasthenozoospermia from ejaculatory duct obstruction treated with transurethral seminal vesiculoscopy between November 2013 and January 2016 in the First Affiliated Hospital of Fujian Medical University were reviewed. A total of 30 cases were persistent hematospermia for 6 months to 3 years, with no response to routine antibiotic therapy for >4 weeks; 24 cases were obstructive azoospermia; and the other 2 cases were extreme oligoasthenozoospermia. Transrectal ultrasound of the prostate and seminal vesicles, and pelvic magnetic resonance imaging (MRI) were performed before the surgery, finding seminal vesicle dilation in 28 cases, ejaculatory duct dilation in 18 cases, seminal vesicle and ejaculatory duct dilation in 7 cases, seminal vesicle dilation with ejaculatory duct cyst in 2 cases, and bilateral ejaculatory duct dilation with prostatic utricle cyst in 1 case. After the transurethral seminal vesiculoscopy, follow-up examinations were performed to assess the effectiveness of the surgery for ≥3 months. Results: The surgery was successful in all the patients, with the duration of surgery ranging from 30 to 148 minutes. Among the 30 patients with hematospermia, calculi in ejaculatory duct or seminal vesicle was found in 20 cases, while inflammation or dark red jelly-like substances in seminal vesicle was seen in all cases. In the follow-up of 9.7 months (3.0-13.0 months), hematospermia in 26 (26/30, 86.7%)patients was relieved or cured after 1-6 times of ejaculation; the other 4 (4/30, 13.3%)cases still had hematospermia. In postoperative semen analysis for the 24 cases of azoospermia from ejaculatory duct obstruction, sperms were detected in 16(16/24, 66.7%)cases, but sperms were not found after 6 months following the surgery in 1 of the 16 case, thus re-obstruction was suspected; in the other 8 (8/24, 33.3%)cases, sperms could not be found in multiple semen analyses in >12 months after the surgery. The 2 cases of extreme oligoasthenozoospermia had obvious improvement in routine semen analysis in 1 and 3 months after the surgery. Except for 1 case of scrotum swelling after surgery, no postoperative complications (retrograde ejaculation, urinary incontinence, or rectal injury) were observed. Conclusions: Transurethral seminal vesiculoscopy was an effective therapy for persistent hematospermia. More strict operation indication and careful performance are necessary for azoospermia oligoasthenozoospermia from ejaculatory duct obstruction.

Efficacy of 694-nm fractional Q-switched ruby laser (QSRL) combined with sonophoresis on levorotatory vitamin C for treatment of melasma in Chinese patients.

Melasma is a common acquired and distressing pigmentary disorder presenting to dermatology clinics. It is notably difficult to cure and has a tendency to relapse. The efficacy of classical Q-switched laser in treatment of melasma remains controversial. This study aims to investigate the efficacy and safety of 694-nm fractional QSRL combined with sonophoresis on levorotatory vitamin C for the treatment of melasma patients. Twenty-six patients with melasma were enrolled. Each patient received four to six fractional QSRL treatments at pulse energies of 2.5 to 4 J/cm(2) combined with sonophoresis on levorotatory vitamin C at 2-week intervals. The severity and the area of melasma were assessed by two investigators using the melasma area and severity index (MASI). Side effects were documented. Mean MASI score decreased from 15.51 ± 3.00 before treatment to 10.02 ± 4.39 3 months after the final treatment (P < 0.01). Side effects were few and transient. High-density coverage fractional QSRL combined with sonophoresis on levorotatory vitamin C is safe and effective for the treatment of melasma in Chinese patients.

Distribution and expression of fibroblast-specific protein chemokine CCL21 and chemokine receptor CCR7 in renal allografts.

We aimed to characterize the expression and distribution of the fibroblast surface protein (FSP), the chemokine CC-ligand 21 (CCL21) secondary lymphoid tissue chemokine CC-chemokine receptor 7 (CCR7) in renal allograft biopsy specimens obtained from patients after transplantation. We recruited 165 patients who received renal transplants at our center for this study. Histological examination of the renal allograft biopsy specimens was performed using hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome staining. Distribution and expression of FSP, CCL21, and CCR7 were determined using immunohistochemistry staining. Serum creatinine levels were evaluated using an enzymatic sarcosine oxidase method. FSP was mainly localized in the cytoplasm and nucleus of renal interstitial fibroblasts and tubular epithelial cells. Compared with the normal group, an elevated number of FSP-positive fibroblasts were observed in patients with acute/active cellular rejection and chronic/sclerosing allograft nephropathy (P < .05). Patients with chronic/sclerosing allograft nephropathy also showed increased total fibroblasts as compared with borderline changes (P < .05). In a multiple regression analysis, CCR7-positive expression was a strong protective factor for acute/active cellular rejection and recurrent nephropathy (odds ratio [OR] = 0.12, P = .034, and OR = 0.08; P = .036, respectively). In contrast, CCL21-positive expression led to a high susceptibility to recurrent nephropathy among renal transplant patients (OR = 10.41, P = .029). Moreover, FSP and CCL21, or CCL21 and CCR7 were localized in the interstitial fibroblasts and renal tubular epithelium cells. In addition, FSP and CCL21 expression positively correlated with serum creatinine levels. Our results suggested that the CCL21/CCR7 signaling pathway is involved in renal fibrosis in kidney transplant patients. An increased number of FSP-positive fibroblasts may be a risk factor for acute/active cellular rejection and chronic/sclerosing allograft nephropathy after renal transplantation. These findings may help understanding of renal allograft fibrosis.

A novel missense mutation L468Q of keratin 6a in pachyonychia congenita type 1.

BACKGROUND: Pachyonychia congenita is an autosomal dominant disorder that usually develops in early infancy. The major features of the syndrome are hypertrophic nail dystrophy, palmoplantar keratoderma and oral leucokeratosis, accompanied by other ectodermal defects, according to subtype. OBJECTIVE: To analyse the K6a gene mutation in a sporadic Chinese patient with pachyonychia congenita type 1 (PC-1) and to explore the relationship between the genotype and phenotype of PC-1. METHODS: Genomic DNA was extracted from peripheral blood of the patient with PC-1 and 100 unrelated controls. The whole coding region of K6a gene was amplified using long-range polymerase chain reaction (PCR); nested PCR was then used to amplify the mutation 'hot-spot' of the K6a gene. The PCR products were directly sequenced to detect the mutation. RESULTS: A novel missense mutation L468Q in the helix 2B domain of the K6a polypeptide was identified in the patient but not in the healthy individuals from the family and 100 unrelated control individuals. CONCLUSIONS: We describe this mutation for the first time, and provide further evidence that the helix boundary motif sequences of K6a are a mutation 'hot-spot'.

Effects of methylprednisolone and aprotinin on phospholipase D activity of leukocytes in systemic inflammatory response induced by cardiopulmonary bypass.

AIM: To investigate the role of leukocyte phospholipase D (PLD) in systemic inflammatory response induced by cardiopulmonary bypass (CPB) and the effects of methylprednisolone and aprotinin on leukocyte PLD activity. METHODS: Forty-two patients who received CPB open heart surgery were divided into 3 groups: methylprednisolone group, aprotinin group, and control group. Arterial blood (10 mL) was collected for assay of leukocyte PLD activity, myeloperoxidase (MPO) activity, and CD11b expression at 8 different time points in perioperative period. Plasma IL-6, IL-8, and C-reactive protein levels were also determined. RESULTS: At the time point of ascending aorta declamped, leukocyte PLD activity for control group was (18 +/- 8) nmol choline . h-1 . mg-1, which was higher than that of pre-CPB (P < 0.01); the PLD activity for methylprednisolone group was (10 +/- 6) nmol choline . h-1 . mg-1 that was lower than control (P < 0.05), while it had no statistical difference compared with that of pre-CPB. In methylprednisolone group, PLD activity elevation was postponed to the time point of CPB stopped. There was no statistical difference in PLD activity between aprotinin group and control (P > 0.05). After administration of methylprednisolone or aprotinin, leukocyte CD11b expression, plasma IL-6, IL-8, C-reactive protein levels, and MPO activity decreased by different extent. CONCLUSION: Leukocyte PLD activity was elevated significantly in systemic inflammatory response induced by CPB and methylprednisolone partially blunted the CPB-induced inflammatory response by inhibiting PLD activity.

Does aluminum inhibit pollen germination via extracellular calmodulin?

The effect of aluminum (Al) on pollen germination and its mechanism of action were investigated. Pollen germination and pollen tube elongation were inhibited by Al at pH 4.5. This inhibitory effect was reversed by the addition of purified calmodulin (CaM), whereas neither the calcium binding-protein S-100 nor Al chelator citric acid at the same concentrations had any obvious effect on Al-inhibited pollen germination. The presence of either the membrane-impermeable CaM inhibitor anti-CaM antiserum or Ca2+ chelator EGTA completely suppressed the effect of exogenous CaM. These results indicate the involvement of extracellular calmodulin in the short-term effects of Al on pollen germination and pollen tube elongation.

[Progress in the study of cyclic nucleotide phosphodiesterases].

There are five families of cyclic nucleotide phosphodiesterase isozymes, which have a common structure, but have different biochemical characteristics, physiologic functions and regulatory mechanisms. Various selective phosphodiesterase inhibitors may have potential uses for antiasthmatic, inotropic, vasodilative, antithrombotic and antidepressant drugs.

Colforsin or imidazolidione potentiates cAMP elevation caused by endothelin-1 in rat aorta.

Endothelin-1 (ET-1) caused slow-developing and stable vasoconstrictions in isolated rings of rat thoracic aortae with a pD2 value of 7.55 +/- 0.10 compared to pD2 values of 9.30 +/- 0.10 and 8.36 +/- 0.30 for angiotensin II and norepinephrine, respectively. Although the potency of ET-1 was somewhat lower than those of norepinephrine and angiotensin II, the maximal tension generated by ET-1 was comparable to that of norepinephrine and considerably greater than that of angiotensin II. Incubation of aortic rings in the absence of extracellular Ca2+ or in the presence of the Ca2+ channel blocker nifedipine (100 nmol.L-1) greatly attenuated ET-1-induced vasoconstriction. ET-1 (20 nmol.L-1, approximately the ED50 for vasoconstrictions) also caused elevation of cAMP levels in aortic rings after 15 and 25 min of exposure. The cAMP phosphodiesterase inhibitor imidazolidione (Imi, Ro 20-1724, 100 mumol.L-1) potentiated the cAMP responses to ET-1. Rings incubated for 25 min with ET-1 (20 nmol.L-1) showed much larger cAMP elevations caused by colforsin (Col, forskolin 1 mumol.L-1), a direct adenylate cyclase activator and potentiator, than with Col or ET-1 alone. Therefore, ET-1 may utilize at least 2 signal transduction mechanisms, one involving the opening of nifedipine-sensitive Ca2+ channels and the other involving the elevation of cAMP levels, to produce the unusually slow-developing and stable vasoconstrictions in rat aortae.

Stimulation of beta adrenoceptors in a human monocyte cell line (U937) up-regulates cyclic AMP-specific phosphodiesterase activity.

Experiments were conducted using undifferentiated U937 cells, a human monocytic cell line, to establish an in vitro model to examine the hormonal regulation of the cyclic AMP (cAMP)-specific phosphodiesterase (PDE IV). Standard chromatographic techniques, coupled with the use of inhibitors and activators that are selective for various phosphodiesterase (PDE) isozymes, were used to establish the PDE isozyme profile in supernatant fractions of U937 cells. When PDE activity was assessed using 1 microM [3H]cAMP as a substrate, 70 to 90% of the total U937 cell supernatant activity in the major peak eluting from anion-exchange columns was inhibited by 30 microM rolipram, a selective inhibitor of PDE IV. The remaining activity was nearly abolished by 10 microM siguazodan or 10 microM cyclic GMP (cGMP,) selective inhibitors of the cGMP-inhibited PDE. Kinetic analyses of the enzyme activity contained within this major peak of PDE activity revealed a cAMP Km = 3 microM and a rolipram Ki = 0.5 microM, values characteristic of PDE IV. Additional studies revealed the presence of a small amount of Ca++/calmodulin-stimulated PDE, but no cGMP-stimulated PDE or cGMP-specific PDE activity. In an effort to induce PDE activity in intact U937 cells by producing a sustained increase in cAMP content, cells were treated for 4 hr with salbutamol (1 microM), rolipram (30 microM) or a combination of both agents. The combination of salbutamol and rolipram produced a 2- to 3-fold increase in PDE activity in U937 cells; when used alone, rolipram was without effect whereas salbutamol induced an increase that was approximately one-half of that observed with the combination. Isozyme isolation and characterization revealed that the overall elevation of cellular PDE activity could be accounted for by a 2- to 3-fold increase in the Vmax of PDE IV with no change in its Km. The induction of PDE IV by salbutamol was: 1) concentration- and time-dependent; 2) detectable only after prolonged (2-4 hr) agonist exposure; 3) preceded by an increase in cAMP content and an activation of cAMP-dependent protein kinase; 4) mimicked by 8-bromo-cAMP and prostaglandin E2; 5) reversible within 3 hr of salbutamol removal; and 6) abolished by cycloheximide or actinomycin D. Collectively, these results indicate that the major PDE isozyme in the soluble fraction of U937 cells is PDE IV and that the activity of this enzyme is increased markedly in cells after prolonged exposure to agents that increase cAMP content.

Agonist-related differences in the relationship between cAMP content and protein kinase activity in canine trachealis.

We investigated the relationships between relaxation, cyclic AMP (cAMP) accumulation and cAMP-dependent protein kinase (cAMP-PK) activity in canine tracheal smooth muscle. In time course and concentration-response studies, forskolin and isoproterenol elicited relaxation of isolated trachealis strips that was accompanied by an increase in cAMP content and an activation of cAMP-PK. Although these results were consistent with the proposal that cAMP is a second messenger mediating relaxation of airway smooth muscle, close inspection of the data revealed a discrepancy in the relationship between cAMP accumulation and relaxation. To induce equivalent degrees of tracheal relaxation, forskolin generated greater increments in cAMP accumulation than did isoproterenol. On the other hand, the activation state of cAMP-PK correlated reasonably well with relaxation regardless of which agonist was used. Further analysis of the data revealed that the apparent disparity between cAMP accumulation and relaxation could largely be explained at the level of the relationship between cAMP content and cAMP-PK activity: compared to isoproterenol, forskolin induced greater increases in cAMP accumulation to achieve the same activation state of cAMP-PK. These observations lend support to the proposal that in canine trachealis, various components of the cAMP/cAMP-PK cascade exist in distinct subcellular compartments such that not all of the cAMP generated in response to forskolin has access to its target enzyme, cAMP-PK.