Tislelizumab, a novel PD-1 monoclonal antibody in urothelial cancer: A real-world study

OBJECTIVE

Tislelizumab, a monoclonal antibody against programed death protein-1 (PD-1), has shown encouraging antitumor activity in urothelial cancer. This study was designed to assess the efficacy and safety of tislelizumab in urotelial cancer in a real-world setting.

METHODS

The study was a real-world retrospective study undertaken at Liaoning Cancer Hospital & Institute, China. Eligible patients were ≥18 years. Patients received 200-mg tislelizumab monotherapy intravenously every 3 weeks until the disease progressed to intolerable toxicity. Outcomes included an objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety.

RESULTS

Between March 2020 and December 2022, 33 patients were enrolled. The median follow-up was 10.17 (IQR 5.73-12.47) months. Of all 33 patients, ORR and DCR were 30.30% (95% CI 15.6%-48.7%) and 42.42% (95% CI 25.48%-60.78%), respectively. The median PFS was 5.73 (95% CI 3.27-13.00) months, with a 12-month PFS rate of 31.90% (95% CI 19.20%-53.00%). The median OS was 17.7 (95% CI 12.80-not reach) months, with a 12-month OS rate of 67.50% (95% CI 52.70%-86.40%). Eleven (33.33%) and 8 (24.24%) experienced ≥grade 3 treatment-related adverse events (TRAEs) and immune-related Aes, respectively. No treatment-related deaths occurred.

CONCLUSION

The excellent efficacy and controllable safety of tislelizumab in locally advanced or metastatic urothelial cancer suggest that it may be a promising therapeutic option for this population.

Fecal calprotectin as an indicator in risk stratification of pouchitis following ileal pouch-anal anastomosis for ulcerative colitis

BACKGROUND

Pouchitis is the most common complication following restorative proctocolectomy and ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). Fecal calprotectin (FC) is a noninvasive indicator of the intestinal inflammatory status. This study was conducted to evaluate the clinical value of the FC concentration for the diagnosis and risk assessment of pouchitis.

PATIENTS AND METHODS

This retrospective study involved patients who underwent IPAA for UC at Tianjin Medical University General Hospital from January 2015 to January 2019. The patients were categorized into pouchitis and non-pouchitis groups based on their Pouchitis Disease Activity Index (PDAI) score. Laboratory indicators, including the FC concentration, were collected from both groups.

RESULTS

Sixty-six patients with UC after IPAA were included in the study and divided into the non-pouchitis group (n = 40) and pouchitis group (n = 26). The correlation coefficient between the FC concentration and the PDAI score was 0.651 (p < 0.001). Receiver operating characteristic analysis showed that the FC cut-off value for predicting pouchitis was 579.60 μg/g (area under the curve, 0.938). The patients were then divided into three subgroups according to their PDAI score (0-2, 3-6, and ≥7), and significant differences in the FC concentration were found among the three subgroups. The best FC cut-off value for predicting a high risk of pouchitis (PDAI score of 3-6) was 143.25 μg/g (area under the curve, 0.876).

CONCLUSIONS

FC is a useful biomarker in patients with pouchitis. Patients are advised to regularly undergo FC measurement to monitor for pouchitis. An FC concentration in the range of 143.25-579.60 μg/g is predictive of a high risk for pouchitis, and further examination and preventive treatment are necessary in such patients.KEY MESSAGESFecal calprotectin can be used to quantify pouch inflammation.Fecal calprotectin can be used to predict a high risk of pouchitis.

2-Furoic acid associated with the infection of nematodes by Dactylellina haptotyla and its biocontrol potential on plant root-knot nematodes

Dactylellina haptotyla is a typical nematode-trapping fungus that has garnered the attention of many scholars for its highly effective lethal potential for nematodes. Secondary metabolites play an important role in D. haptotyla-nematode interactions, but which metabolites perform which function remains unclear. We report the metabolic functions based on high-quality, chromosome-level genome assembly of wild D. haptotyla YMF1.03409. The results indicate that a large variety of secondary metabolites and their biosynthetic genes were significantly upregulated during the nematode-trapping stage. In parallel, we identified that 2-furoic acid was specifically produced during nematode trapping by D. haptotyla YMF1.03409 and isolated it from fermentation production. 2-Furoic acid demonstrated strong nematicidal activity with an LD50 value of 55.05 µg/mL against Meloidogyne incognita at 48 h. Furthermore, the pot experiment showed that the number of galls of tomato root was significantly reduced in the experimental group treated with 2-furoic acid. The considerable increase in the 2-furoic acid content during the infection process and its virulent nematicidal activity revealed an essential synergistic effect during the process of nematode-trapping fungal infection. IMPORTANCE Dactylellina haptotyla have significant application potential in nematode biocontrol. In this study, we determined the chromosome-level genome sequence of D. haptotyla YMF1.03409 by long-read sequencing technology. Comparative genomic analysis identified a series of pathogenesis-related genes and revealed significant gene family contraction events during the evolution of D. haptotyla YMF1.03409. Combining transcriptomic and metabolomic data as well as in vitro activity test results, a compound with important application potential in nematode biocontrol, 2-furoic acid, was identified. Our result expanded the genetic resource of D. haptotyla and identified a previously unreported nematicidal small molecule, which provides new options for the development of plant biocontrol agents.

[Research progress on the structure and innervation of extraocular muscles]

In addition to the abnormalities of the extraocular muscles themselves and the nervous system innervating the extraocular muscles, the tissue pulley abnormalities around the extraocular muscles may lead to the occurrence of strabismus. In recent years, researchers have shown the intramuscular nerve distribution of the extraocular muscles using the Sihler technique. With the continuous progress of imaging technology, magnetic resonance imaging, computed tomography, anterior segment optical coherence tomography and ultrasound biomicroscopy can be used to observe the attachment sites of the extraocular muscles. This review summarizes the latest research progress on the neuroanatomy of the extraocular muscles, in order to provide reference for the clinical diagnosis and treatment of strabismus.

Identification and Mechanism of Action of the Global Secondary Metabolism Regulator SaraC in Stereum hirsutum

DNA methylation is an important factor in the regulation of gene expression. In analyzing genomic data of Stereum hirsutum FP-91666, we found a hypothetical bifunctional transcription regulator/O6Meguanine-DNA methyltransferase (named SaraC), which is widely present in both bacteria and fungi, and confirmed that its function in bacteria is mainly for DNA reparation. In this paper, we confirmed that SaraC has the function of DNA binding and demethylation through surface plasma resonance and reaction experiments in vitro. Then, we achieved the overexpression of SaraC (OES) in S. hirsutum, sequenced the methylation and transcription levels of the whole-genome, and further conducted untargeted metabolomics analyses of the OES transformants and the wild type (WT). The results confirmed that the overall-methylation levels of the transformants were significantly downregulated, and various genes related to secondary metabolism were upregulated. Through comparative untargeted metabolomic analyses, it showed that OES SA6 transformant produced a greater number of hybrid polyketides, and we identified 2 novel hybrid polyketides from the fermentation products of SA6. Our results show that overexpression SaraC can effectively stimulate the expression of secondary-metabolism-related genes, which could be a broad-spectrum tool for discovery of metabolites due to its cross-species conservation. IMPORTANCE Fungi are one of the important sources of active compounds. However, in fungi, most of the secondary metabolic biosynthetic gene clusters are weakly expressed or silenced under conventional culture conditions. How to efficiently excavate potential new compounds contained in fungi is becoming a research hot spot in the world. In this study, we found a DNA demethylation protein (SaraC) and confirmed that it is a global secondary metabolism regulator in Stereum hirsutum FP-91666. In the past, SaraC-like proteins were mainly regarded as DNA repair proteins, but our findings proved that it will be a powerful tool for mining secondary metabolites for overexpression of SaraC, which can effectively stimulate the expression of genes related to secondary metabolism.

[Hepatic cystic echinococcosis complicated with tuberculous empyema misdiagnosed as hepatic and pulmonary cystic echinococcosis: one case report]

Hepatic cystic echinococcosis is a chronic parasitic disease caused by the infection with the larvae of Echinococcus granulosus in human or animal liver tissues. As a chronic active infectious disease, tuberculous empyema mainly invades the pleural space and then causes visceral and parietal pleura thickening. It is rare to present comorbidity for hepatic cystic echinococcosis and tuberculous empyema. This case report presents a case of hepatic cystic echinococcosis complicated with tuberculous empyema misdiagnosed as hepatic and pulmonary cystic echinococcosis, aiming to improve clinicians' ability to distinguish this disorder.

Case Report: An Unusual Case of Pulmonary Metastatic Adenocarcinoma From Low-Grade Appendiceal Mucinous Neoplasms

Background

Low-grade appendiceal mucinous neoplasms (LAMNs) are indolent tumors with low-grade cytology. Although peritoneal dissemination is common due to tumor rupture and mucinous deposits on the visceral peritoneal surface, distant involvement, such as lung, is rarely seen due to lack of invasiveness.

Case Presentation

A 70-year-old woman presented to the hospital due to continuously elevated carcinoembryonic antigen (CEA) levels for 10 months without any symptoms. PET/CT revealed two lesions located in the left lung and appendix. The postoperative pathology results revealed pulmonary mucinous adenocarcinoma and LAMN. Then we performed next-generation sequencing (NGS) to clarify the relationship between the two tumors. The sequencing result showed that both tumors harbored the common tumor mutations, KRAS (p.G12D), GNAS (p.R201H), and BRAF (p.R735Q), which indicated that the pulmonary tumor was a metastasis of LAMN.

Conclusion

This case is unusual in that the primary LAMN and the pulmonary metastasis are present at the time of diagnosis. This study reported the first pulmonary metastasis from LAMN verified by NGS.

Identification of Nematicidal Metabolites from Purpureocillium lavendulum

Purpureocillium lavendulum is a fungus with promising biocontrol applications. Here, transcriptome data acquired during the infection of Caenorhabditis elegans by Purpureocillium lavendulum showed that the transcription of metabolite synthesis genes was significantly up-regulated after 24 and 48 h of the fungus-nematode interaction. Then, the up-regulated transcription level of lipoxygenase was confirmed by RT-qPCR. The ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) analysis of differential metabolites revealed that this interaction resulted in the emergence of new metabolites or enhanced the production of metabolites. The results of the UPLC-MS analysis and the nematicidal assay were used to establish optimal culturing conditions under which 12 metabolites, including 3 hydroxylated C18 fatty acids and 9 steroids, were isolated and identified. Among them, hydroxylated fatty acids showed pronounced nematicidal activity against Meloidogyne incognita, and two degradative sterols showed chemotaxis activity to M. incognita. This study lays a foundation for the function of lipoxygenase and its products during the infection of Purpureocillium lavendulum.

Recent Advances in the Synthetic Biology of Natural Drugs

Natural drugs have been transformed and optimized during the long process of evolution. These compounds play a very important role in the protection of human health and treatment of human diseases. Sustainable approaches to the generation of raw materials for pharmaceutical products have been extensively investigated in drug research and development because chemical synthesis is costly and generates pollution. The present review provides an overview of the recent advances in the synthetic biology of natural drugs. Particular attention is paid to the investigations of drugs that may be mass-produced by the pharmaceutical industry after optimization of the corresponding synthetic systems. The present review describes the reconstruction and optimization of biosynthetic pathways for nine drugs, including seven drugs from plant sources and two drugs from microbial sources, suggesting a new strategy for the large-scale preparation of some rare natural plant metabolites and highly bioactive microbial compounds. Some of the suggested synthetic methods remain in a preliminary exploration stage; however, a number of these methods demonstrated considerable application potential. The authors also discuss the advantages and disadvantages of the application of synthetic biology and various expression systems for heterologous expression of natural drugs. Thus, the present review provides a useful perspective for researchers attempting to use synthetic biology to produce natural drugs.

Visceral-to-Subcutaneous Fat Ratio Is a Potential Predictor of Postoperative Complications in Colorectal Cancer

Background

Colorectal cancer (CRC) is one of the most common malignant tumors. Surgery is the primary treatment for CRC. Recent studies have shown that visceral-to-subcutaneous fat ratio (VSR) may be a potential indicator of risk. The aim of the present study was to determine whether VSR is a suitable predictor of the impact of postoperative complications in CRC.

Material/Methods

Clinical data from 129 patients were analyzed retrospectively. All patients underwent laparoscopic surgery for CRC. Preoperative imaging was used to quantify VSR. The primary outcome was 30-day postoperative complications. Multivariate logistic regression was used to determine the association between obesity indexes and postoperative complications.

Results

There were 129 patients who underwent primary resections of colorectal cancer. At 30 days after surgery, postoperative complications had occurred in 33 (25.6%) patients. VSR was significantly associated with postoperative complications in multivariate analysis (P=0.032, OR 6.103, 95% CI 1.173–31.748). In ROC analysis, VSR was a potential predictor of complications (AUC 0.650). A cutoff value of VSR ≥0.707 was associated with 60% sensitivity and 29% specificity for postoperative complications. Patients with VSR ≥0.707 had 41.7% risk of morbidity, whereas those with <0.707 had 16.0% risk (P=0.001).

Conclusions

Our study shows that VSR is superior to VFA for prediction of the risk of complications following CRC laparoscopic surgery. We have also identified the optimal cutoff values for the use of VSR for this purpose. Measurement of VSR and identifying patients with increased risk of postoperative complications facilitate making perioperative decisions.

Gastroduodenitis associated with ulcerative colitis: A case report

BACKGROUND

Ulcerative colitis (UC) is defined as a chronic inflammatory bowel disease that can occur in any part of the large bowel. In addition, UC affects only the large bowel except for backwash ileitis and pouchitis, whereas Crohn's disease (CD) affects the entire digestive tract. Inflammatory bowel disease (IBD) patients tend to be diagnosed with CD or indeterminate colitis when combined with gastric lesion. However, in recent years, some UC patients are reported to have various degrees of lesions in gastroduodenum. Here, we report a case of gastroduodenitis associated with UC (GDUC).

CASE SUMMARY

A 25-year-old man with a history of Klippel-Trenaunay syndrome presented to the hospital with mucopurulent bloody stool and epigastric persistent colic pain for 2 wk. Continuous superficial ulcers and spontaneous bleeding were observed under colonoscopy. Subsequent gastroscopy revealed mucosa with diffuse edema, ulcers, errhysis, and granular and friable changes in the stomach and duodenal bulb, which were similar to the appearance of the rectum. After ruling out other possibilities according to a series of examinations, a diagnosis of GDUC was considered. The patient hesitated about intravenous corticosteroids, so he received a standardized treatment with pentasa of 3.2 g/d. After 0.5 mo of treatment, the patient’s symptoms achieved complete remission. Follow-up endoscopy and imaging findings showed no evidence of recurrence for 26 mo.

CONCLUSION

The occurrence of gastrointestinal involvement in UC is rare, which may open a new window for studying the etiology and pathogenesis of UC. Physicians should consider broad differential diagnosis by endoscopic biopsy and laboratory examinations.

Intestinal obstruction in pregnancy with reverse rotation of the midgut: A case report

BACKGROUND

Reverse rotation of the midgut is a rare type of intestinal malrotation. Volvulus of the right colon or entire midgut, stenosis of the transverse colon and obstruction of the duodenojejunal junction are common complications of reverse rotation. In this study, we report the first case of intestinal obstruction associated with reverse rotation in pregnancy.

CASE SUMMARY

A 31-year-old woman at 36⁺² wk gestation presented to the emergency department with progressive abdominal cramping, nausea and bilious vomiting. Abdominal ultrasound scanning showed dilatation of the bowel. Computed tomography scanning revealed features of reverse rotation of the midgut with intestinal volvulus. After consultation with the obstetrician, the pregnancy was terminated and exploratory abdominal surgery was performed. Intra-operatively, it was found that the mesentery of the colon and small intestine was insufficiently attached. The right colon and the small intestinal mesentery was twisted, and intestinal necrosis was observed. The duodenum and duodenojejunal junction were curved in front of the transverse colon, and the transverse colon passed through the tunnel behind the mesenteric root. Intestinal reverse rotation with volvulus was confirmed. The ‌necrotic intestine was resected and small intestine mesenteric reconstruction was performed. The patient recovered after surgery. After leaving the hospital, the patient and her daughter remained well during an 8-month follow-up period.

CONCLUSION

We report the diagnosis, treatment and etiology of a pregnant patient with intestinal obstruction due to reverse rotation of the midgut. For similar cases, appropriate diagnosis and treatment should be carried out according to the condition of the fetus and pregnant woman.

[Clinical characteristics of recurrent appendicitis]

Objective: To analyze clinical characteristics of recurrent appendicitis. Methods: A retrospective cohort study was carried out. Clinical data of patients who underwent appendectomy due to acute appendicitis confirmed by pathology in the Affiliated Hospital of Qingdao University from January 2011 to December 2015 were analyzed retrospectively. Exclusion criteria: (1) age of less than 18 years;(2) chronic appendicitis; (3) periappendiceal abscess; (4) appendiceal mucocele or mucinous neoplasms; (5) appendiceal neuroendocrine tumors or cancers; (6) appendicitis during pregnancy; (7) concurrent AIDS, hematological disease, autoimmune disease, inflammatory bowel disease or advanced cancer; (8) other simultaneous surgery. A total of 373 patients were enrolled the study. These patients were divided into the recurrent group (133 cases) and the first episode group (240 cases) according to the previous history of antibiotic therapy for acute appendicitis. The prevalence of recurrent appendicitis was calculated, and the clinical characteristics were analyzed, including gender, age, comorbidities and preoperative CT images. Results: Of 373 patients, 209 were male and 164 were female, with a median age of 42 (18 to 88) years. Median recurrent time of the recurrent group was 4 (1 to 60) months. Compared to the first episode group, the recurrent group had higher proportion of age <50 years [71.4% (95/133) vs. 57.5% (138/240), χ(2)=7.081, P=0.008], higher proportion of concurrent diabetes [13.5% (18/133) vs. 5.4% (13/240), χ(2)=7.399, P=0.007], shorter onset time [(41.7±13.6) hours vs. (59.4±56.2) hours, t=-3.286, P=0.001], lower proportion of abdominal tension and rebound pain [57.9% (77/133) vs. 66.7% (160/240), χ(2)=5.065, P=0.024], lower score of modified Alvarado score [(5.6±1.9) point vs. (6.1±1.9) point, t=-2.417, P=0.016], lower WBC count [(10.5±4.6) ×10(9)/L vs. (11.5±4.5)×10(9)/L, t=-1.190, P=0.047], higher percentage of lymphocyte [(19.4±14.7)% vs. (16.1±13.3)%, t=2.069, P=0.039]. In the recurrent group, ratio of length of removed appendix ≥7 cm was higher as compared with the first episode group [44.4% (59/133) vs. 32.9% (79/240), χ(2)=4.808, P=0.028], while the ratio of complicated appendicitis was significantly lower [8.3% (11/133) vs. 22.9% (55/240), χ(2)=10.823, P=0.001]. CT images were available in 129 patients, intraluminal appendicoliths was found in 19 of 50 patients (38%) in the recurrent group, while in 16 of 79 patients (20.3%) in the first episode group, and there was statistically significant difference between the two groups (χ(2)=4.880, P=0.027). Conclusions: Clinical characteristics of recurrent acute appendicitis include age less than 50 years, concurrent diabetes, short onset time, less abdominal tension or rebound pain, low modified Alvarado score, low WBC count, high percentage of lymphocyte, appendix length longer than 7 cm, non-complicated appendicitis and intraluminal appendicoliths.

[Perioperative management of pregnant women combined with congenital fibrinogen deficiency: four cases report and literature review]

Congenital fibrinogen deficiency is an autosomal recessive or dominant disorder in which quantitative (afibrinogenaemia or hypofibrinogenaemia) or qualitative (dysfibrinogenaemia) defects in the fibrinogen Aa, Bb or c protein chains that lead to reduced functional fibrinogen. We now report the perioperative management of 4 pregnant women suffering from hypofibrinogenaemia scheduled for elective caesarean section from December 2012 to October 2016 in Peking University First Hospital and review this disease with reference to classification, symptom, replacement therapy, and selection of the modes of pregnancy termination and anesthesia. The four patients were all asymptomatic, whereas there existed recurrent pregnancy loss (case 3), family history (case 2), and offspring heredity (cases 3 and 4). Routine clotting studies revealed low fibrinogen levels and prolonged thrombin time (TT) during pregnancy and on admission. However, the platelet (PLT) count, prothrombin time (PT) and activated partial thromboplastin time (APTT) were normal. All the patients were administered fibrinogen concentrate perioperatively, and underwent uncomplicated combined spinal-epidural anesthesia and uneventful surgical procedure without postpartum hemorrhage. The replacement therapy of fibrinogen or fresh frozen plasma administration was essential to avoid anesthesia and obstetric complications. Regional blockade could safely be offered in the caesarean section, providing that their coagulation defect was corrected by availability of therapeutic products and adequate response to treatment. In addition, the point-of-care rotational thrombelastometry (ROTEM) or thrombelastogram (TEG) could play an important role in an optimal perioperative management for such patients. Management plans must be tailored to each individual, taking into consideration their bleeding risk as well as potential maternal and neonatal complications.

Influence of Hydrostatic Pressure on the Corrosion Behavior of Superhydrophobic Surfaces on Bare and Oxidized Aluminum Substrates

It is generally recognized that superhydrophobic surfaces in water may be used for corrosion resistance due to the entrapped air in the solid/liquid interface and could find potential applications in the protection of ship hull. For a superhydrophobic surface, as its immersion depth into water increases, the resultant hydrostatic pressure is also increased, and the entrapped air can be squeezed out much more easily. It is therefore predicted that high hydrostatic pressure would cause an unexpected decrease in corrosion resistance for the vessels in deep water (e.g., submarines) because of the unstable entrapped air. In this work, in order to clarify the role of hydrostatic pressure in the corrosion behavior of superhydrophobic surfaces, two typical superhydrophobic surfaces (SHSs) were prepared on bare and oxidized aluminum substrates, respectively, and then were immersed into the NaCl aqueous solutions with different depths of ∼0 cm (hydrostatic pressure ∼0 kPa), 10 cm (1 kPa), and 150 cm (15 kPa). It was found out for the SHSs on the oxidized Al, as the hydrostatic pressure increased, the corrosion behavior became severe. However, for the SHSs on the bare Al, their corrosion behavior was complex due to hydrostatic pressure. It was found that the corrosion resistance under 1 kPa was the highest. Further mechanism analysis revealed that this alleviated corrosion behavior under 1 kPa resulted from suppressing the oxygen diffusion through the liquid and reducing the subsequent corrosion rate as compared with 0 kPa, whereas the relatively low hydrostatic pressure (HP) could stabilize the entrapped air and hence enhance the corrosion resistance, compared with 15 kPa. The present study therefore provided a fundamental understanding for the applications of SHSs to prevent the corrosion, especially for various vessels in deep water.

Early Hemodynamic Response Assessment of Stereotactic Radiosurgery for a Cerebral Arteriovenous Malformation Using 4D Flow MRI

Brain AVMs treated with stereotactic radiosurgery typically demonstrate a minimum latency period of 1-3 years between treatment and nidus obliteration. Assessment of treatment response is usually limited to evaluation of AVM nidus structural changes using conventional MR imaging and MRA techniques. This report describes the use of 4D Flow MRI to also measure radiation-induced hemodynamic changes in a Spetzler-Martin grade III AVM, which were detectable as early as 6 months after treatment.

[Effects of recent upper respiratory-tract infections on incidence of the perioperative respiratory adverse events in children: a prospective cohort study]

OBJECTIVE

To investigate the effects of the recent upper respiratory tract infections (URI) on the incidence of perioperative respiratory adverse events in children scheduled to undergo general anesthesia and elective surgery.

METHODS

In the study, 232 children undergoing general anesthesia with laryngeal mask airway (LMA) for elective ophthalmic surgeries at Peking University First Hospital, Beijing, China, from Nov. 1, 2015 to May 10, 2016 were enrolled. On the day of the surgery, the parents of the children were preoperatively asked to fill out a questionnaire regarding the baseline characteristics and medical history of the children, including gender, age, height, weight, history of URI within the last 2 weeks before anesthesia, history of premature, long-term passive smoking exposure, habitual sleep snoring, and history of asthma. In addition, all adverse respiratory events throughout the perioperative periods (oxygen desaturation, cough, copious secretions, laryngospasm and bronchospasm) as well as peri-operative variables (number of attempts to insert the LMA successfully, anesthesia duration and so on) were recorded. Multivariate Logistic regression analysis was applied to identify independent risk factors of perioperative respiratory adverse events.

RESULTS

Among the 232 children included in the study, 28.0% (65/232) presented with a history of a recent URI within the last 2 weeks before anesthesia. The presence of the recent URI increased the incidence of oxygen desaturation (23.1% vs.12.0%, P=0.034), copious secretions (15.4% vs. 6.6%, P=0.036) and any of all the adverse respiratory events (32.3% vs. 18.6%, P=0.024). Multivariate Logistic regression analysis identified two independent risk factors of perioperative adverse respiratory events: a history of URI within the last 2 weeks before general anesthesia (OR=2.021, 95%CI: 1.023-3.994, P=0.043) and habitual sleep snoring (OR=3.660, 95%CI: 1.517-8.832, P=0.004).

CONCLUSION

A history of a recent URI within 2 weeks before general anesthesia was associated with a higher incidence of oxygen desaturation, copious secretions and the overall respiratory adverse events. For the children with recent URI, we recommend the general anesthesia and elective surgery should be postponed for at least 2 weeks after the URI.

Blood service in the Tibetan regions of Garzê and Aba, China: a longitudinal survey

BACKGROUND

Garzê and Aba form the second largest Tibetan-inhabited area of China. Blood services have never been reported for this region before.

OBJECTIVE

To assess the current situation and analyse whether a safe and adequate blood supply has been developed in both Garzê and Aba.

METHODS

We conducted a longitudinal survey covering the period 2011-2016. The subjects of interest were recruited from non-remunerated voluntary donation, blood testing, clinical transfusion practices and infrastructure of local blood service systems.

RESULTS

The donation rate and blood collection volume were below the average levels of both the Sichuan Province and mainland China. Component therapy was widely used, but inappropriate usage of whole blood existed. A lack of national specific standards for people on the plateaus led to local blood transfusions being conducted without full clinical assessment. Endemic and frequently occurring disease, such as hydatid disease and gastrointestinal disease, were inevitable risks for blood utilisation and safety. The potential influence of religious belief and traditions, like 'male-leaving marriages', of Tibetans on donor recruitment and blood safety requires further research.

CONCLUSIONS

A relatively safe and complete blood service system has been developed in this region. However, there is still an urgent need for comprehensive and effective support from the government in terms of policies and finance. As an epidemic area of hydatid disease and sexually transmitted disease, this region needs to emphasise public health measures, such as blood safety and inappropriate usage of blood products.

Natural ageing responses of duplex structured Mg-Li based alloys

Natural ageing responses of duplex structured Mg-6%Li and Mg-6%Li-6%Zn-1.2%Y alloys have been investigated. Microstructural analyses revealed that the precipitation and coarsening process of α-Mg particles could occur in β-Li phases of both two alloys during ageing process. Since a certain amount of Mg atoms in β-Li phases were consumed for the precipitation of abundant tiny MgLiZn particles, the size of α-Mg precipitates in Mg-6%Li-6%Zn-1.2%Y alloy was relatively smaller than that in Mg-6%Li alloy. Micro hardness measurements demonstrated that with the ageing time increasing, the α-Mg phases in Mg-6%Li alloy could have a constant hardness value of 41 HV, but the contained β-Li phases exhibited a slight age-softening response. Compared with the Mg-6%Li alloy, the age-softening response of β-Li phases in Mg-6%Li-6%Zn-1.2%Y alloy was much more profound. Meanwhile, a normal age-hardening response of α-Mg phases was maintained. Tensile results indicated that obvious ageing-softening phenomenon in terms of macro tensile strength occurred in both two alloys. Failure analysis demonstrated that for the Mg-6%Li alloy, cracks were preferentially initiated at α-Mg/β-Li interfaces. For the Mg-6%Li-6%Zn-1.2%Y alloy, cracks occurred at both α-Mg/β-Li interfaces and slip bands in α-Mg and β-Li phases.

Abdominal wall endometriosis occurring after cesarean section: an underestimated complication

The aim of the study was to review patients characteristics, describe the exact anatomic locations and size of the endometriosis in the abdominal wall, and discuss the factors that may contribute to mesh use during abdominal wall endometriosis (AWE) resection.

MATERIALS AND METHODS

Patients diagnosed with AWE in their surgical scars from January 2008 to December 2014 were documented. Descriptive data was collected and analyzed.

RESULTS

A total of 95 patients with an age ranging from 26 to 48 years, with a mean age of 33.5 ?5.0 years at the time of excision were analyzed. The mean diameter of the mass was 3.25 cm in the present series with an average of 4.97 cm in the mesh group by ultrasound. A total of 18 patients had mesh therapy for fascia defect compared with 77 non-mesh therapy patients. The size of the lesions, the mean duration of symptoms for painful mass, and level of the serum CA125 were statistically different between mesh group and non-mesh group (p < 0.05). Cases of endometriosis lesions limited to the adipose layer had significant lower chance of using mesh (p < 0.05). However, adipose layer endometriosis lesions that had penetrated through the fascia layer and invaded into rectus abdominis muscle layer with/without peritoneum layer had significant higher chance of using mesh (p < 0.05).

CONCLUSIONS

The more common position for scar endometriosis may be in the adipose layer at the corner of the surgical scar. Mesh therapy should be considered before surgery when the diameter of the abdominal wall mass detected by ultrasound is more than five em and/or when the lesions invade into rectus abdominis muscle with/without peritoneum tissues from adipose and fascia layers.

Prevalence of hepatitis A viral RNA and antibodies among Chinese blood donors

Like other developing countries, China was reported to have a relatively high seroprevalence of anti-hepatitis A antibodies (anti-HAV). However, no studies have evaluated the prevalence of anti-HAV and HAV RNA among voluntary blood donors with or without elevated serum alanine transaminase (ALT) levels. Anti-HAV antibodies were detected using an enzyme-linked immunosorbent assay, and reverse transcription quantitative polymerase chain reaction was carried out for detection of HAV RNA. In the current study, we analyzed a total of 450 serum samples with elevated ALT levels (≥40 U/L) and 278 serum samples with non-elevated ALT levels. Seroprevalence rates of anti-HAV were 51.6% in donors with elevated ALT and 41.4% in donors with non-elevated ALT; however, none of the samples was positive for HAV RNA. The results of our study showed lower seroprevalence rates of anti-HAV in blood donors (irrespective of ALT levels) than those in published data on Chinese populations. Although donors with elevated ALT had statistically higher prevalence rates of anti- HAV than did those with non-elevated ALT, none of the serum samples had detectable levels of the active virus. In conclusion, our results demonstrate that the transmission of hepatitis A by blood transfusion will occur rarely.

Application of indirect linkage analysis and direct genotyping to hemophilia A carrier detection in Sichuan, China

Hemophilia A (HA) is an inherited X-linked bleeding disorder caused by mutations in the factor VIII gene. Prenatal detection in female carriers from families with HA is important to reduce the number of HA patients. The purpose of this study was to detect carriers in families with HA from Sichuan, China, using linkage analysis and a direct genotyping method. A total of 18 HA families were studied. Using a combination of intron 22 inversion, intron 1 inversion, the BclI polymorphic site in intron 18, the HindIII polymorphic site in intron 19, and dinucleotide CA-repeat markers in introns 1, 13, 22, and 24, we were able to detect HA in 88.9% (16/18) of the families studied. HA was detected in the remaining two families by direct genotyping. This study gave the participants a good understanding of their genetic condition and gave us a preliminary understanding of the prevalence of each mutation in Sichuan HA patients.

Cohn process influences the functional anticoagulant activity of human protein C

Cohn fraction IV (CFIV) is a byproduct of a plasma fractionation process known as the Cohn process. It is an inexpensive source of protein C, retaining about 90% of protein C (PC) in human plasma. We investigated whether PC is affected during the Cohn process and evaluated correlations among coagulant activity, amidolytic activity and PC antigen during the Cohn process. CFIV was redissolved with citrate-buffered saline for 5 h at 4°C, and then centrifuged at 3500 g for 40 min at 4°C. Functional anticoagulant activity was measured with a one-stage coagulation method based on activated partial thromboplastin time. The functional amidolytic activity of PC was determined using chromogenic substrate assay, and measurement of PC antigen was performed by ELISA. In CFIV, anticoagulant activity declined significantly, with a loss of >80%, while amidolytic activity was not significantly altered, compared to PC antigen. Prior to the Cohn process, high-rank correlations were observed in cryosupernatant, with rs = 0.921 for anticoagulant and amidolytic activities (P = 0.009), 0.896 for anticoagulant activity and antigen (P = 0.014) and 0.832 for amidolytic activity and antigen (P = 0.031). After the Cohn process in CFIV, there was also a high correlation between amidolytic activity and antigen (rs = 0.782, P = 0.038). There were no significant correlations between anticoagulant activity and antigen (rs = 0.223, P = 0.653), or anticoagulant and amidolytic activity (rs = 0.236, P = 0.675). We conclude that the Cohn process significantly influences the anticoagulant activity of PC. Compared to the antigen, PC lost greater than 80% of its anticoagulant activity, but retained its amidolytic activity, during the Cohn process.

Expression and fast preparation of biologically active recombinant human coagulation factor VII in CHO-K1 cells

Human coagulation factor VII (FVII) plays an important role in the blood coagulation process and exists in micro amounts in human plasma; therefore, any attempt at the large-scale production of FVII in significant quantities is challenging. The purpose of this study was to express and obtain biologically active recombinant FVII (rFVII) from Chinese hamster ovary K1 (CHO-K1) cells. The full-length FVII cDNA was isolated from a HepG2 cell line and then subcloned in pcDNA3.1 to construct an expression vector, pcDNA-FVII. CHO-K1 cells were transfected with 1 µg pcDNA-FVII. The cell line that stably expressed secretory FVII was screened using 900 µg/mL G418. The FVII copy number in CHO-K1 cells was detected by quantitative polymerase chain reaction (qPCR). The rFVII was purified in ligand affinity chromatography medium. The purified protein was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The biological activity of the purified FVII protein was determined by a prothrombin time assay. Three cell lines that permanently expressed rFVII were screened. The qPCR results demonstrated that each CHO-K1 cell harbored two FVII DNA copies. The SDS-PAGE and Western blot analysis showed that the purified protein was about 50 kDa. The purity of the target protein was 95%. The prothrombin time assay indicated that the FVII-specific activity of rFVII was 2573 ± 75 IU/mg. This method enabled the fast preparation of high-purity rFVII from CHO-K1 cells, and the purified protein had good biological activity.

Construction of tissue-engineered composite intervertebral disc and preliminary morphological and biochemical evaluation

The aim of this study was to construct tissue-engineered composite intervertebral disc (IVD) consisting of demineralized bone matrix gelatin (DBMG) and collagen II/hyaluronate/chondroitin-6-sulfate (CII/HyA-CS) scaffolds seeded with anulus fibrosus (AF) and nucleus pulposus (NP) cells, respectively. The cell-scaffold hybrids were implanted in the subcutaneous space of the dorsum of athymic mice and harvested at 4, 8, and 12 weeks. At each time point, the gross and histological morphology and biochemical properties were evaluated. Our results are as following: the gross morphology and histology of the composite resembled those of native IVD. Morphological studies revealed progressive tissue formation and junction integration between AF and NP regions. Biochemical composition detection indicated that the content of DNA, proteoglycan and hydroxyproline increased with time, and were similar to native tissue at 12 weeks. All these results demonstrated the feasibility of creating a tissue-engineered composite IVD with similar morphological and biochemical properties to the native tissue.

Differentiation of colonic polyps by confocal laser endomicroscopy

BACKGROUND AND STUDY AIM

The real-time identification and removal of adenomas is a cost-effective strategy to improve the prognosis of colorectal cancer. Confocal laser endomicroscopy (CLE) could provide real-time histological-level observation. We aimed to evaluate the efficacy of CLE diagnosis using a simple classification system that differentiates adenomas from non-neoplastic polyps with intravenous fluorescein staining alone.

PATIENTS AND METHODS

An endoscope integrated confocal laser microscopy system was used in this study. CLE images of 35 colonic polyps, including 15 hyperplastic polyps and 20 adenomas confirmed by histology, were first evaluated to develop criteria for diagnosis of neoplastic and non-neoplastic polyps. The diagnostic criteria included goblet cell depletion, villous architecture, and microvascular alterations. We then performed a prospective study of colonic polyps found during CLE and classified them according to the established criteria. A total of 115 patients with 115 colonic polyps were included. The real-time CLE diagnosis was compared with that from histology. The stored CLE images were evaluated later by a blinded observer.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of real-time CLE in identifying colonic adenomas were 93.9 % (95 % confidence interval [CI] 85.4 - 97.6), 95.9 % (95 % CI 86.2 - 98.9), 96.9 % (95 % CI 89 - 99), and 92.2 % (95 % CI 81 - 97), respectively, compared with histological results. Interobserver agreement between real-time and post-CLE still-image evaluation was excellent (kappa = 0.929). Goblet cell depletion alone had a sensitivity of 84.9 % (95 % CI 73 - 92) and a specificity of 87.8 % (95 % CI 75 - 95), as well as excellent interobserver agreement (kappa = 0.824).

CONCLUSIONS

Endoscope integrated CLE with fluorescein staining may reliably assist in the real-time identification of colonic adenomas. Among three diagnostic categories, goblet cell depletion can be used to distinguish adenomas and hyperplastic polyps.

Confocal laser endomicroscopy for superficial esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIMS

Confocal laser endomicroscopy (CLE) allows subsurface imaging of gastrointestinal mucosa in vivo. The goal of the present study was to compare the endomicroscopic characteristics of cells and intrapapillary capillary loops (IPCLs) in normal and superficial esophageal squamous cell carcinoma (SESC).

PATIENTS AND METHODS

We recruited consecutive patients with SESC diagnosed by conventional endoscopy and confirmed by histopathology between July 2006 and May 2008. The confocal endoscopic images of these patients were collected and compared with the corresponding histology. The characteristic patterns of cells and IPCLs was then analyzed from these images of malignant and normal mucosa. The quality of images and interobserver variations of two endoscopists were also evaluated.

RESULTS

Overall, 64 samples from 57 subjects (27 SESCs, 30 controls) were examined by CLE. The confocal images corresponded to the hematoxylin and eosin staining from the same sites. The confocal images showed that there was a significantly higher proportion of squamous epithelial cells with irregular arrangement (79.4 % vs. 10.0 %, P < 0.001), increased diameter of IPCLs (26.0 microm vs. 19.2 microm, P < 0.001), and irregular shape IPCLs (82.4 % vs. 36.7 %, P = 0.0002) in the SESC group compared with the controls. Massive IPCLs with tortuous vessels (44.1 % vs. 0 %, P < 0.0001), and long branching IPCLs (23.5 % vs. 3.3 %, P = 0.0204) were frequently observed in the SESC group. In this study, about 35.5 % of images were graded as good quality, and the interobserver agreement for the prediction of cancerous mucosa was graded as substantial.

CONCLUSIONS

CLE can be used to distinguish cancerous from normal epithelium, which gives it potential value for early detection of esophageal carcinoma. The difficulty in obtaining good images in the esophagus by CLE is a latent problem.

Cytotoxicity induced by grape seed proanthocyanidins: role of nitric oxide

Grape seed proanthocyanidin extract (GPSE) at high doses has been shown to exhibit cytotoxicity that is associated with increased apoptotic cell death. Nitric oxide (NO), being a regulator of apoptosis, can be increased in production by the administration of GSPE. In a chick cardiomyocyte study, we demonstrated that high-dose (500 microg/ml) GSPE produces a significantly high level of NO that contributes to increased apoptotic cell death detected by propidium iodide and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. It is also associated with the depletion of intracellular glutathione (GSH), probably due to increased consumption by NO with the formation of S-nitrosoglutathione. Co-treatment with L-NAME, a NO synthase inhibitor, results in reduction of NO and apoptotic cell death. The decline in reduced GSH/oxidized GSH (GSSG) ratio is also reversed. N-Acetylcysteine, a thiol compound that reacts directly with NO, can reduce the increased NO generation and reverse the decreased GSH/GSSG ratio, thereby attenuating the cytotoxicity induced by high-dose GSPE. Taken together, these results suggest that endogenous NO synthase (NOS) activation and excessive NO production play a key role in the pathogenesis of high-dose GSPE-induced cytotoxicity.

A novel locus (DSAP2) for disseminated superficial actinic porokeratosis maps to chromosome 15q25.1-26.1

BACKGROUND

Disseminated superficial actinic porokeratosis (DSAP) is a chronic cutaneous disorder characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. It develops in teenagers in sun-exposed areas of skin and usually follows an autosomal dominant inheritance pattern. The first locus for DSAP was localized to chromosome 12q23.2-24.1, but no gene responsible for porokeratosis has been identified to date.

OBJECTIVES

To determine whether DSAP is a genetically heterogeneous disorder and to identify the disease gene locus in a three-generation Chinese family with DSAP.

METHODS

Genetic linkage analysis was carried out in this family using 15 microsatellite markers between D12S1671 and D12S369 on chromosome 12q, followed by a genome-wide scan with 382 microsatellite markers from the autosomes.

RESULTS

Genetic linkage analysis with chromosome 12q markers suggested that the locus in this family is not linked to chromosome 12q. A genome-wide scan and fine mapping finally localized the locus for DSAP in this family to a 6.4-cM region between markers D15S1023 and D15S1030 at chromosome 15q25.1-26.1. This DSAP locus was named DSAP2.

CONCLUSIONS

The previous results and this study have shown that DSAP is a genetically heterogeneous disorder; a novel locus for DSAP, termed DSAP2, was mapped to a 6.4-cM region between markers D15S1023 and D15S1030.

Expression of the amino-terminal domain of platelet glycoprotein Ib alpha: exploitation of a calmodulin tag for determination of its functional activity

Platelet glycoprotein (GP) Ibalpha is a component of the GPIb-IX receptor complex, which is involved in multiple physiological and pathological processes, including platelet adhesion at sites of vascular injury, thrombin binding, Bernard-Soulier syndrome, platelet-type von Willebrand disease, and immune-mediated thrombocytopenias. The amino-terminal domain of approximately 300 residues of GPIbalpha mediates both normal biological function (by providing the sites for direct ligand interaction) and aberrant function (through amino acid substitutions). To investigate the molecular interactions mediated by this region of GPIbalpha, we have developed a recombinant baculovirus to facilitate its expression as a calmodulin fusion protein from insect cells. By employing the calmodulin tag, the fusion protein could be obtained at >90% purity after a single isolation step at yields of 8 mg/L of insect cell medium (purified fusion protein). The recombinant GPIbalpha fragment was shown to be posttranslationally sulfated and glycosylated, although its glycosylation differed from that of the equivalent GPIbalpha fragment isolated from human platelets. The differential glycosylation, however, did not affect the function of the recombinant GPIbalpha fragment in either von Willebrand factor (vWf) or thrombin binding as these were both found to be identical to those of the same-length GPIbalpha fragment derived from human platelets. The calmodulin tag was also exploited in the development of assays to measure directly vWf and thrombin binding, since it did not interfere with either, demonstrating the feasibility for the use of this soluble receptor fusion protein in detailed biophysical assays to investigate the molecular mode of binding of platelet glycoprotein Ibalpha to these ligands.

The recruitment of Fas-associated death domain/caspase-8 in Ras-induced apoptosis

Oncogenic Ras induces cells to undergo apoptosis after inhibition of protein kinase C (PKC) activity. The integration of differential signaling pathways is required for full execution of apoptosis. In this study, we used Jurkat as well as Fas/FADD-defective cell lines expressing v-ras to determine the upstream elements required for activation of the caspase cascade in PKC/Ras-mediated apoptosis. During this Ras-induced apoptotic process, caspase-8 was activated, possibly through its binding to Fas-associated death domain (FADD), in Jurkat/ras and Jurkat/Fas(m)/ras cells but not in Jurkat/FADD(m)/ras cells. c-Jun NH(2)-terminal kinase (JNK) was activated in all three cell lines expressing ras in response to apoptotic stimulation. Suppression of JNK by dn-JNK1 blocked the interaction of FADD and caspase-8 and partially protected Jurkat/ras and Jurkat/Fas(m)/ras cells from apoptosis. However, dn-JNK1 had no effect on PKC/Ras-induced apoptosis in Jurkat/FADD(m)/ras cells. The results indicate that FADD/caspase-8 signaling is involved in PKC/Ras-mediated apoptosis, and JNK may be an upstream effector of caspase activation.

Increased oxidative and nitrative stress in human stomach associated with cagA+ Helicobacter pylori infection and inflammation

In order to study the role of Helicobacter pylori infection in gastric carcinogenesis, we have measured oxidized (carbonyls) and nitrated (nitrotyrosine-containing) proteins as markers for oxidative and nitrative stress in 216 human gastric biopsies using dot and western immunoblots and correlated the results with H. pylori, cagA status, expression of interleukin-8 and inducible nitric oxide synthase (iNOS) mRNAs, and gastric pathology. Higher levels of both oxidized and nitrated proteins were found in patients with either chronic gastritis or duodenal ulcer than in those with normal mucosa. The levels of modified proteins were significantly higher in inflamed samples infected with H. pylori, especially cagA+ strains, and in those with expression of interleukin-8 and iNOS mRNAs than in those negative for these parameters. These results indicate that infection with cagA+ H. pylori induces significant oxidative and nitrative stress in stomach mucosa, contributing to the pathogenesis of H. pylori-associated gastroduodenal diseases.

Platelet glycoprotein Ib alpha binds to thrombin anion-binding exosite II inducing allosteric changes in the activity of thrombin

The glycoprotein (GP) Ib-IX complex is a platelet surface receptor that binds thrombin as one of its ligands, although the biological significance of thrombin interaction remains unclear. In this study we have used several approaches to investigate the GPIb alpha-thrombin interaction in more detail and to study its effect on the thrombin-induced elaboration of fibrin. We found that both glycocalicin and the amino-terminal fragment of GPIb alpha reduced the release of fibrinopeptide A from fibrinogen by about 50% by a noncompetitive allosteric mechanism. Similarly, GPIb alpha caused in thrombin an allosteric reduction in the rate of turnover of the small peptide substrate d-Phe-Pro-Arg-pNA. The K(d) for the glycocalicin-thrombin interaction was 1 microm at physiological ionic strength but was highly salt-dependent, decreasing to 0.19 microm at 100 mm NaCl (Gamma(salt) = -4.2). The salt dependence was characteristic of other thrombin ligands that bind to exosite II of this enzyme, and we confirmed this as the GPIb alpha-binding site on thrombin by using thrombin mutants and by competition binding studies. R68E or R70E mutations in exosite I of thrombin had little effect on its interaction with GPIb alpha. Both the allosteric inhibition of fibrinogen turnover caused by GPIb alpha binding to these mutants, and the K(d) values for their interactions with GPIb alpha were similar to those of wild-type thrombin. In contrast, R89E and K248E mutations in exosite II of thrombin markedly increased the K(d) values for the interactions of these thrombin mutants with GPIb alpha by 10- and 25-fold, respectively. Finally, we demonstrated that low molecular weight heparin (which binds to thrombin exosite II) but not hirugen (residues 54-65 of hirudin, which binds to exosite I of thrombin) inhibited thrombin binding to GPIb alpha. These data demonstrate that GPIb alpha binds to thrombin exosite II and in so doing causes a conformational change in the active site of thrombin by an allosteric mechanism that alters the accessibility of both its natural substrate, fibrinogen, and the small peptidyl substrate d-Phe-Pro-Arg-pNA.

Nitrated and oxidized plasma proteins in smokers and lung cancer patients

Cigarette smoking is a cause of lung cancer and other respiratory diseases. Oxidants either present in cigarette smoke and/or formed in the lung of smokers may trigger oxidative and nitrative damage to DNA and cellular components, contributing to carcinogenesis. We have used immunodot and Western blot analyses to measure nitrated (nitrotyrosine-containing) and oxidized (carbonyl-containing) proteins in plasma samples collected from 52 lung cancer patients and 43 control subjects (heavy and light smokers, nonsmokers with or without exposure to environmental tobacco smoke). The levels of nitrated proteins were significantly higher in lung cancer patients than in controls (P = 0.003). On the other hand, the levels of oxidized proteins were significantly higher in smokers than in nonsmokers (P < 0.001). Western-blot analyses showed the presence of two to five nitrated proteins and one oxidized protein. Using immunoprecipitation and Western-blot analyses with eight different antibodies against human plasma proteins, we identified fibrinogen, transferrin, plasminogen, and ceruloplasmin as nitrated proteins and fibrinogen as the only oxidized protein present in human plasma of lung cancer patients and smokers. Our results indicate that cigarette smoking increases oxidative stress and that during lung cancer development, formation of reactive nitrogen species results in nitration and oxidation of plasma proteins.

[Potential anxiolytic role of c-fos antisense oligonucleotide in social-defeated rats]

OBJECTIVES

This study was to explore the therapeutic potential of c-fos antisense phosphorothioate oligonucleotide and the possible molecular mechanism.

METHODS

On the basis of the sequence of c-fos mRNA, two 15-mer phosphorothioated oligodeoxynucleotide(ODN) were synthesized. Antisense ODN was corresponded to the initiation codon of c-fos mRNA. The complementary sense and vehicle(saline) served as controls. Anxiety was induced in rats by a social-defeated paradigm and then rats were given a 5-minute exposure to the plus maze and open field test. Rats were injected c-fos antisense, sense ODNs and vehicles into the lateral ventricle through stainless-steel guide cannulate implanted unilaterally from the beginning of the experiment. The expression of the protein product of the immediate early gene c-fos was analyzed with immunochemistry in different brain regions, such as the amygdala and paraventricularis hypothalami nucleus. Computer assisted image analysis was performed to quantify the results of immuno-cytochemistry.

RESULTS

Socially defeated c-fos antisense-treated rats displayed obviously reduced anxiety-related behavior, as they spent significantly more time in the open arms of the plus maze compared to sense ODN- and vehicle-treated rats. The behavioral effects were similar to those of established anti-anxiety drugs(diazepam). Antisense oligodeoxynucleotide significantly decreased Fos positive nucleus in paraventricularis hypothalami nucleus. The inhibitory efficiency was 57.03%.

CONCLUSION

Our data provide further evidence that c-fos is involved in acute stress elicited anxiety related behavior.

Platelet glycoprotein ibalpha is a counterreceptor for the leukocyte integrin Mac-1 (CD11b/CD18)

The firm adhesion and transplatelet migration of leukocytes on vascular thrombus are both dependent on the interaction of the leukocyte integrin, Mac-1, and a heretofore unknown platelet counterreceptor. Here, we identify the platelet counterreceptor as glycoprotein (GP) Ibalpha, a component of the GP Ib-IX-V complex, the platelet von Willebrand factor (vWf) receptor. THP-1 monocytic cells and transfected cells that express Mac-1 adhered to GP Ibalpha-coated wells. Inhibition studies with monoclonal antibodies or receptor ligands showed that the interaction involves the Mac-1 I domain (homologous to the vWf A1 domain), and the GP Ibalpha leucine-rich repeat and COOH-terminal flanking regions. The specificity of the interaction was confirmed by the finding that neutrophils from wild-type mice, but not from Mac-1-deficient mice, bound to purified GP Ibalpha and to adherent platelets, the latter adhesion being inhibited by pretreatment of the platelets with mocarhagin, a protease that specifically cleaves GP Ibalpha. Finally, immobilized GP Ibalpha supported the rolling and firm adhesion of THP-1 cells under conditions of flow. These observations provide a molecular target for disrupting leukocyte-platelet complexes that promote vascular inflammation in thrombosis, atherosclerosis, and angioplasty-related restenosis.

Necessity of conserved asparagine residues in the leucine-rich repeats of platelet glycoprotein Ib alpha for the proper conformation and function of the ligand-binding region

The polypeptides of the platelet von Willebrand factor (vWf) receptor, the GP Ib-IX-V complex, each contain tandem repeats of a sequence that assigns them to the leucine-rich repeat protein family. Here, we studied the role of conserved Asn residues in the leucine-rich repeats of GP Ib alpha, the ligand-binding subunit of the complex. We replaced the Asn residue in the sixth position of the first or sixth leucine-rich repeat (of seven) either with a bulky, charged Lys residue or with a Ser residue (sometimes found in the same position of other leucine-rich repeats) and studied the effect of the mutations on complex expression, modulator-dependent vWf binding, and interactions with immobilized vWf under fluid shear stress. As predicted, the Lys substitutions yielded more severe phenotypes, producing proteins that either were rapidly degraded within the cell (mutant N158K) or failed to bind vWf in the presence of ristocetin or roll on immobilized vWf under fluid shear stress (mutant N41K). The binding of function-blocking GP Ib alpha antibodies to the N41K mutant was either significantly reduced (AK2 and SZ2) or abolished (AN51 and CLB-MB45). Ser mutations were tolerated much better, although both mutants demonstrated subtle defects in vWf binding. These results suggest a vital role for the conserved asparagine residues in the leucine-rich repeats of GP Ib alpha for the structure and functions of this polypeptide. The finding that mutations in the first leucine-rich repeat had a much more profound effect on vWf binding indicates that the more N-terminal repeats may be directly involved in this interaction.

Preconditioning in cardiomyocytes protects by attenuating oxidant stress at reperfusion

Cardiomyocyte death after ischemia/reperfusion correlates with oxidant stress, and antioxidants confer protection in that model. Preconditioning (PC) with hypoxia or adenosine also confers protection, leading us to hypothesize that PC protects by attenuating oxidant generation during subsequent ischemia/reperfusion. Chick cardiomyocytes were preconditioned with 10 minutes of hypoxia or adenosine (100 micromol/L), followed by 1 hour of simulated ischemia and 3 hours of reperfusion. Adenosine PC decreased cell death from 50+/-3% to 18+/-4% and enhanced the return of contractions during reperfusion, as observed previously with hypoxic PC. A transient burst of dichlorofluorescein (sensitive to H2O2 oxidation that was significantly attenuated by PC initiated by hypoxia or adenosine was seen at reperfusion. The protein kinase C (PKC) inhibitor Go-6976 and the mitochondrial ATP-sensitive K(+) (K(ATP)) channel inhibitor 5-hydroxydecanoate each abolished protection and abrogated the PC-induced attenuation of reperfusion oxidant stress. By contrast, when given only at reperfusion, the K(+) channel opener pinacidil or the antioxidants 2-mercaptopropionylglycine and 1,10-phenanthroline decreased oxidant stress at reperfusion and improved survival and return of contractions. Thus, PC protection is associated with an attenuation of the oxidant burst at reperfusion, regardless of the method by which PC is triggered. Loss of PC protection associated with PKC inhibition or K(ATP) channel inhibitors is associated with a restoration of that oxidant stress. These results suggest a mechanism for PC protection and reveal a functional link between PKC activation and K(ATP) channel activation in that pathway.

Interaction of von Willebrand factor domain A1 with platelet glycoprotein Ibalpha-(1-289). Slow intrinsic binding kinetics mediate rapid platelet adhesion

We investigated the crucial hemostatic interaction between von Willebrand factor (VWF) and platelet glycoprotein (GP) Ibalpha. Recombinant VWF A1 domain (residues Glu(497)-Pro(705) of VWF) bound stoichiometrically to a GPIbalpha-calmodulin fusion protein (residues His(1)-Val(289) of GPIbalpha; GPIbalpha-CaM) immobilized on W-7-agarose with a K(d) of 3.3 microM. The variant VWF A1(R545A) bound to GPIbalpha-CaM 20-fold more tightly, mainly because the association rate constant k(on) increased from 1,100 to 8,800 M(-1) s(-1). The GPIbalpha mutations G233V and M239V cause platelet-type pseudo-von Willebrand disease, and VWF A1 bound to GPIbalpha(G233V)-CaM and GPIbalpha(M239V)-CaM with a K(d) of 1.0 and 0.63 microM, respectively. The increased affinity of VWF A1 for GPIbalpha(M239V)-CaM was explained by an increase in k(on) to 4,500 M(-1) s(-1). GPIbalpha-CaM bound with similar affinity to recombinant VWF A1, to multimeric plasma VWF, and to a fragment of dispase-digested plasma VWF (residues Leu(480)/Val(481)-Gly(718)). VWF A1 and A1(R545A) bound to platelets with affinities and rate constants similar to those for binding to GPIbalpha-CaM, and botrocetin had the expected positively cooperative effect on the binding of VWF A1 to GPIbalpha-CaM. Therefore, allosteric regulation by botrocetin of VWF A1 binding to GPIbalpha, and the increased binding affinity caused by mutations in VWF or GPIbalpha, are reproduced by isolated structural domains. The substantial increase in k(on) caused by mutations in either A1 or GPIbalpha suggests that productive interaction requires rate-limiting conformational changes in both binding sites. The exceptionally slow k(on) and k(off) provide important new constraints on models for rapid platelet tethering at high wall shear rates.

Threonine-145/methionine-145 variants of baculovirus produced recombinant ligand binding domain of GPIbalpha express HPA-2 epitopes and show equal binding of von Willebrand factor

Glycoprotein (GP) Ibalpha is the functionally dominant subunit of the platelet GPIb-IX-V receptor complex, with the von Willebrand factor (vWF) binding site residing on the amino-terminus. A threonine for methionine-145 replacement of GPIbalpha is associated with the human platelet antigen (HPA)-2 system. To study the structural and functional consequences of this mutation, both forms of GPIbalpha were expressed as calmodulin fusion proteins in insect cells. Both recombinant proteins were recognized by their respective alloantibodies, independent of glycosylation or intactness of disulfide bonds, and gave similar results to platelet-derived GPIbalpha in antibody detection assays. Resonant mirror studies showed that vWF binding was not affected by the HPA-2 mutation; however, vWF binding was partially inhibited by IgG HPA-2 antibodies. Our data are compatible with an involvement of the leucine-rich repeat domain of GPIbalpha in vWF binding and indicate that recombinant GPIbalpha may be used to detect HPA-2 antibodies. (Blood. 2000;95:205-211)

Coexpression of interleukin-8 and inducible nitric oxide synthase in gastric mucosa infected with cagA+ Helicobacter pylori

The cagA-positive Helicobacter pylori strains are thought to be able to induce interleukin-8 expression and to be associated with gastroduodenal diseases. Inducible nitric oxide synthase (iNOS) may be involved in inflammatory pathogenesis. Our aim was to investigate the interrelationships between cagA and the expression of interleukin-8 and iNOS messenger RNAs, and with the type and degree of inflammation in gastric mucosa. In biopsies from 108 Chinese patients, the cagA, 16S rRNA, interleukin-8, and iNOS mRNAs were analyzed using reverse-transcription polymerase chain reaction. Specimens infected with cagA-positive strains had significantly more severe infiltration by mononuclear and polymorphonuclear leukocytes and more frequently expressed interleukin-8 and iNOS mRNAs than those infected with cagA-negative strains. iNOS and interleukin-8 mRNAs were significantly more frequently expressed together in the specimens with moderate or severe inflammation than in those with normal mucosa or mild inflammation. Our data suggest that interleukin-8 and excess nitric oxide play important roles in the pathogenesis of H. pylori-associated gastroduodenal diseases.

Generation of superoxide in cardiomyocytes during ischemia before reperfusion

Although a burst of oxidants has been well described with reperfusion, less is known about the oxidants generated by the highly reduced redox state and low O(2) of ischemia. This study aimed to further identify the species and source of these oxidants. Cardiomyocytes were exposed to 1 h of simulated ischemia while oxidant generation was assessed by intracellular dihydroethidine (DHE) oxidation. Ischemia increased DHE oxidation significantly (0.7 +/- 0.1 to 2.3 +/- 0.3) after 1 h. Myxothiazol (mitochondrial site III inhibitor) attenuated oxidation to 1.3 +/- 0.1, as did the site I inhibitors rotenone (1.0 +/- 0.1), amytal (1.1 +/- 0.1), and the flavoprotein oxidase inhibitor diphenyleneiodonium (0.9 +/- 0.1). By contrast, the site IV inhibitor cyanide, as well as inhibitors of xanthine oxidase (allopurinol), nitric oxide synthase (nitro-L-arginine methyl ester), and NADPH oxidase (apocynin), had no effect. Finally, DHE oxidation increased with Cu- and Zn-containing superoxide dismutase (SOD) inhibition using diethyldithiocarbamate (2.7 +/- 0.1) and decreased with exogenous SOD (1.1 +/- 0.1). We conclude that significant superoxide generation occurs during ischemia before reperfusion from the ubisemiquinone site of the mitochondrial electron transport chain.

Extract from Scutellaria baicalensis Georgi attenuates oxidant stress in cardiomyocytes

Extract from Scutellaria baicalensis Georgi Attenuates Oxidant Stress in Cardiomyocytes. Journal of Molecular and Cellular Cardiology (1999) 31, 1885-1895. Scutellaria baicalensis Georgi is a Chinese herbal medicine used to treat allergic and inflammatory diseases. The medicinal effects of S. baicalensis root may result, in part, from its constituent flavones reported to have antioxidant properties. Since oxidants play multiple roles in cells, we tested whether S. baicalensis could confer protection in a cardiomyocyte model of ischemia and reperfusion. The intracellular fluorescent probes 2',7'-dichlorofluorescin diacetate (DCFH-DA, sensitive to H(2)O(2) and hydroxyl radicals) and dihydroethidium (DHE, sensitive to superoxide) were used to assess intracellular reactive oxygen species (ROS), and propidium iodide (PI) was used to assess viability in cultured embryonic cardiomyocytes. S. baicalensis extract (SbE) quickly attenuated levels of oxidants generated during transient hypoxia and during exposure to the mitochondrial site III inhibitor antimycin A, as measured by DCFH oxidation or by DHE oxidation. These attenuated oxidant levels were associated with improved survival and function. Cell death after ischemia/reperfusion decreased from 47+/-3 % in untreated to 26+/-2 % in S. baicalensis treated cells (P<0.001). After antimycin A exposure, S. baicalensis decreased cell death from 49+/-6 % in untreated to 23+/-4 % in treated cells. Return of contraction occurred in S. baicalensis-treated cells but was not observed in control cells. Other in vitro studies revealed that baicalein, a major flavone component of SbE can directly scavenge superoxide, hydrogen peroxide, and hydroxyl radicals. Collectively, these findings indicate that SbE and its constituent flavones such as baicalein can attenuate oxidant stress and protect cells from lethal oxidant damage in an ischemia-reperfusion model.

The use of significant reduction rates to evaluate health education methods for pregnant smokers: a new harm reduction behavioral indicator?

This article evaluates the evidence to support the use of biochemical measurement of significant reduction (SR) rates among pregnant smokers as a new behavioral indicator of "harm reduction" (HR). The results of four studies--three randomized patient education clinical trials of pregnant smokers (Trials I, II, and III) and an epidemiological study (Study IV)--are presented. Among Trial I, II, and III cohorts of pregnant smokers, control group SR rates of 7% (I), 9% (II), and 20% (III) were increased among experimental groups to 17% (I), 18% (II), and 32% (III) by the same patient education methods. Analyses of infant birthweight data in Study IV found that a patient SR rate representing a 50% or more decrease between a baseline and follow-up test was associated with an increase in adjusted birthweight of 92 grams.

Kozak sequence polymorphism of the glycoprotein (GP) Ibalpha gene is a major determinant of the plasma membrane levels of the platelet GP Ib-IX-V complex

Despite the known importance of the sequences surrounding ATG start codons (Kozak sequences) for efficient translation of proteins, few reports have appeared that describe the natural variations in these sequences. Here, we report a human polymorphism in the Kozak sequence of the platelet adhesion receptor, glycoprotein (GP) Ibalpha, a component of the GP Ib-IX-V complex, which mediates the initial adhesion of platelets to the blood vessel wall following injury. The polymorphism is based on the presence of either thymine (T) or cytosine (C) at position -5 from the initiator ATG in the GP Ibalpha gene. The less common allele, -5C, represented 8% to 17% of the alleles in four ethnic populations surveyed. This allele more closely resembles the sequence considered optimal for efficient initiation of protein translation and is associated with increased expression of the receptor on the cell membrane, both in transfected cells and in the platelets of individuals carrying the allele. In vitro transcription/translation studies indicate that the increased expression results from more efficient translation of the -5C form of the GP Ibalpha mRNA. Other mutations made to approximate more closely the consensus sequence described by Kozak did not increase expression of the receptor. This is the first known description of Kozak sequence polymorphism as a determinant of the surface levels of a cell adhesion receptor. This polymorphism may influence an individual's susceptibility for the development of cardiovascular disease.

Effect of inhaled interleukin-5 on number and activity of eosinophils in circulation from asthmatics

The aim of the present study was to examine the effects of interleukin-5 (IL-5) inhalation on changes in the activity and number of circulating eosinophils, as well as concentrations of serum total IgE, in allergic asthmatics. A randomized double-blind, placebo-controlled study design was employed in which each subject acted as his or her own control. Eight nonsmoking patients with allergic asthma were administered recombinant human IL-5 by nebulization. Total white blood cell counts and differentials, as well as concentrations of ECP and total IgE in serum, were determined before and at 2, 24, and 48 h after inhalation. Our results demonstrated that eosinophil numbers increased from baseline (3.6 +/- 1.1 x 10(5)/ml) to 6.3 +/- 1.2 x 10(5)/ml (P < 0.01) at 24 h and to 5.7 +/- 0.9 x 10(5)/ml (P < 0.01) at 48 h after IL-5 inhalation in asthmatics. Accompanying this significantly increased blood eosinophilia were significantly elevated serum ECP levels. Compared with baseline (6.3 +/- 1.1 ng/ml), ECP levels increased with time following IL-5 inhalation, reaching 17.6 +/- 2.8 ng/ml (P < 0.01) at 24 h and remaining elevated at 48 h (18.1 +/- 2.9 ng/ml, P < 0.01). IL-5 inhalation had no significant effect on levels of serum total IgE, however. These findings provide direct evidence that nebulized IL-5 not only induces a significant blood eosinophilia but also results in the activation of circulating eosinophils. Our data further support the importance of IL-5 in the pathogenesis of bronchial asthma in humans.

Seroconversion of type B to O erythrocytes using recombinant Glycine max alpha-D-galactosidase

Recombinant alpha-D-galactosidase (rGal) from soybean (Glycine max) hydrolyzed the immunodominant alpha-D-galactose residue from the B epitope of red blood cells. This converted type B erythrocytes to type O which are "universally" transfusable. Type B red blood cells were obtained from four different donors and enzymatically converted. Cell function parameters, including red cell indices, pH, methemoglobin, carboxyhemoglobin, osmotic fragility, hemolysis, 2,3-diphosphoglycerate, cholinesterase, ATP, and antigen typing of treated cells were compared to controls. These pilot studies indicate that rGal could have potential biotechnical application in the production of universally transfusable red blood cells.

The cytoplasmic domain of glycoprotein (GP) Ibalpha constrains the lateral diffusion of the GP Ib-IX complex and modulates von Willebrand factor binding

To study the role of the glycoprotein (GP) Ibalpha cytoplasmic domain in the mobility of the GP Ib-IX complex within the plasma membrane and in its ability to bind vWf, we established eight cell lines expressing GP Ib-IX complexes (these complexes lack GP V but function normally as receptors for vWf) that contain either wild-type GP Ibalpha or one of a series of GP Ibalpha truncation mutants missing different lengths of the cytoplasmic domain. To test the mobility of these complexes within the plasma membrane, we used the technique of fluorescence recovery after photobleaching after labeling them with a fluorescein-conjugated anti-GP Ibalpha monoclonal antibody. Fluorescence recovery within a bleached area on the cell surface was evaluated by scanning the cell surface with a low-intensity laser for 3 min after bleaching and then extrapolating the recovery values to infinite time. Fluorescence recovery in cells expressing wild-type GP Ibalpha was negligible. However, when only six amino acids were removed from the GP Ibalpha carboxyl terminus (t604 mutant, polypeptide length of 604 vs 610 residues for wild-type GP Ibalpha), complex mobility increased greatly, as judged by a more rapid recovery of fluorescence in the bleached area (48% recovery). The mobility increased further in the t594 mutant and remained approximately the same through the t534 mutant (55-67% recovery). A further increase in mobility was observed with the t518 mutant (>80% recovery), which lacks almost all of the GP Ibalpha cytoplasmic domain. The ristocetin-dependent binding of the mutant cell lines was also evaluated. Binding of vWf to cells expressing any of the mutant complexes was markedly lower than that to cells expressing the wild-type complex. These studies demonstrate that the cytoplasmic domain of GP Ibalpha fixes the position of the GP Ib-IX complex on the platelet surface and that this orientation is an important determinant of the complex's ability to bind vWf.