[Developing traditional medical heritage for further achievements in medical history and literature research-Commemorating the establishment of China Institute for History of Medicine and Medical Literature in the China Academy of Traditional Chinese Medicine]

The Institute of Chinese Medical History and Literature in the China Academy of Traditional Chinese Medicine was officially established on May 28, 1982. Its predecessor was the Medical History Research Office in the Chinese Medicine Institute of the Central Institute of Health, the Editorial Office of the China Academy of Traditional Chinese Medicine, and the Theory and Literature Research Office of the Institute of Acupuncture and Moxibustion. Before that, the Research Office of Chinese Medical History and Literature in the China Academy of Traditional Chinese Medicine was established in 1971. It made remarkable achievements in scientific research, personnel training and discipline construction in terms of medical history and literature. It was upgraded to the Institute with the approval of the Ministry of Health in 1980. After its establishment, the institute has benefited from great achievements.

P11.37.B When to resect or biopsy for patients with supratentorial glioblastoma: a multivariable prediction model

Background

The prospects of a patient with suspected glioblastoma may rely heavily on the indication for surgical resection versus biopsy only. Biopsy percentages vary considerably across hospitals and guidelines for treatment of glioblastoma lack criteria for surgical decision-making. To identify patient and tumor characteristics associated with the decision to resect or biopsy a glioblastoma and to develop and validate a prediction model for decision support.

Material and Methods

Clinical data and pre-operative MRI scans were collected for adults who underwent first-time surgery for supratentorial glioblastoma from a registry-based cohort study of 12 hospitals from the Netherlands, Germany, France, Italy, and the United States between 1st of January 2007 and 31st of December 2011. The main outcome was the type of surgical procedure: surgical resection or biopsy only. Predictors were patient- and tumor-related characteristics. Radiological factors were extracted from MRI using an automated tumor segmentation method. A prediction model was constructed using multivariable logistic regression analysis. The model was cross-validated and externally validated with a leave-one-hospital-out approach.

Results

Out of 1053 patients treated for glioblastoma, 28% underwent biopsy only. Biopsy rates varied from 15-40% across hospitals. The prediction model showed excellent discrimination with an average area under the curve of 0.86. Of the patient-related characteristics, younger age was associated more with resection and Karnofsky Performance Score of 60 or less with biopsy. Of the tumor-related characteristics, a location in the right hemisphere, unifocality, no tumor midline crossing, and no involvement of the cortical spinal tract, were associated with resection, as well as a high expected resectability index, a location in the right occipital lobe, and a higher percentage of tumor in Schaefer’s dorsal or ventral attention, limbic, and default networks. External validation proved acceptable to outstanding discrimination with areas under the curve ranging between 0.79 and 0.92 for hospitals.

Conclusion

A prediction model is presented and validated to support the decision to resect or to biopsy a patient with a suspected supratentorial glioblastoma. In this prediction model, tumor-related characteristics were more informative than patient-related factors. This may support surgical decision-making for individual patients, or facilitate comparisons of patient cohorts between surgeons or institutions.

Molecular Mechanism and Prevention Strategy of Chemotherapy- and Radiotherapy-Induced Ovarian Damage

Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

[Tour of the History Exhibition Hall of the Chinese Academy of Chinese Medical Sciences: To commemorate the 65th anniversary of the Chinese Academy of Chinese Medical Sciences]

In 2015, 60th anniversary of China Academy of Chinese Medical Sciences(CACMS), the History Exhibition Hall of it was opened to the public. The History Exhibition Hall collecting 29504 pages of documents, and 26386 pictures, 1050 materials, reveal the history of founding and development of CACMS. 2020 is the 65th anniversary of CACMS. Taking the 87 groups representative collections as examples, briefly review the development history of CACMS from five aspects: figures, scientific research, medical treatment, education and industry.

[The preliminary clinical study on radical prostatectomy without preoperative prostate biopsy]

Objective: To investigate the feasibility and safety of minimally invasive radical prostatectomy for prostate cancer patients without preoperative prostate biopsy in the new era of the continuous development of comprehensive new imaging diagnostic mode and minimally invasive surgery technology. Methods: From August 2018 to October 2019, 17 patients with prostate cancer were enrolled in this study in the Cancer Hospital, Chinese Academy of Medical Sciences. All patients were highly suspected of prostate cancer by PSMA-PET/CT-based imaging diagnostic techniques and underwent 3D laparoscopic radical prostatectomy without prostate biopsy. The perioperative data, postoperative pathology, postoperative complications and follow-up results were recorded and analyzed. Results: The average age of 17 patients with prostate cancer was (65±7) years. The body mass index (BMI) average was (24.4±3.0) kg/m(2). The American Society of Anesthesiologists (ASA) score was 1 (1-2) and the Charlson comorbidity index (CCI) score was 1 (0-4). The preoperative value of PSA was (19±11) μg/L. The PSMA PET/CT showed abnormally high expression foci and the great possibility of prostate cancer for all the 17 patients. Prostate puncture biopsy: the results of prostate biopsy were negative in 3 cases. The digital rectal examination found that the prostate volume was Ⅰ or Ⅱ degree large, 10 cases touched hard and the nodule was touched in two cases. Three patients had undergone a previous prostate biopsy, but prostate cancer was not found. All the 17 operations were successfully performed without conversion to open surgery. The surgery time was (85±21) (range from 45 to 120) min, the estimated blood loss was (25±18) (range from5 to 100) ml, the time of intake of liquid diet was (14.3±4.4) h, the intestinal recovery time was (23±10) h, the postoperative activity time was (22±7) h, the drainage duration was (3.7±0.8) d, the postoperative hospital stay was (4.9±1.2) days, and the catheter removal time was (7.4±1.5) days. In the early postoperative period (within 30 days after surgery), no obvious complications occurred. The postoperative final pathology confirmed that all the 17 specimens were prostate cancer. After a median follow-up of 6.5 months, the patient's urinary control rate reached 81.3% at postoperative 1 month, 92.3% at postoperative 3 months after surgery, and the urinary control rate reached 100% at postoperative 6 months. Postoperative PSA value was (0.08±0.08) μg/L, significantly lower than preoperative PSA level (P<0.001). There was significant difference between the preoperative and postoperative QOL (Quality of life) score (57±5 and 47±5 respectively, P<0.001) which indicated that the patients' postoperative quality of life was greatly improved. Conclusions: It is safe and feasible to perform minimally invasive radical prostatectomy without preoperative prostate biopsy for patients with highly suspected prostate cancer by comprehensive diagnostic mode based on modern new imaging technology.

Distinguishing Extravascular from Intravascular Ferumoxytol Pools within the Brain: Proof of Concept in Patients with Treated Glioblastoma

BACKGROUND AND PURPOSE

Glioblastoma-associated macrophages are a major constituent of the immune response to therapy and are known to engulf the iron-based MR imaging contrast agent, ferumoxytol. Current ferumoxytol MR imaging techniques for localizing macrophages are confounded by contaminating intravascular signal. The aim of this study was to assess the utility of a newly developed MR imaging technique, segregation and extravascular localization of ferumoxytol imaging, for differentiating extravascular-from-intravascular ferumoxytol contrast signal at a delayed 24-hour imaging time point.

MATERIALS AND METHODS

Twenty-three patients with suspected post-chemoradiotherapy glioblastoma progression underwent ferumoxytol-enhanced SWI. Segregation and extravascular localization of ferumoxytol imaging maps were generated as the voxelwise difference of the delayed (24 hours) from the early (immediately after administration) time point SWI maps. Continuous segregation and extravascular localization of ferumoxytol imaging map values were separated into positive and negative components. Image-guided biologic correlation was performed.

RESULTS

Negative segregation and extravascular localization of ferumoxytol imaging values correlated with early and delayed time point SWI values, demonstrating that intravascular signal detected in the early time point persists into the delayed time point. Positive segregation and extravascular localization of ferumoxytol imaging values correlated only with delayed time point SWI values, suggesting successful detection of the newly developed extravascular signal.

CONCLUSIONS

Segregation and extravascular localization of ferumoxytol MR imaging improves on current techniques by eliminating intrinsic tissue and intravascular ferumoxytol signal and may inform glioblastoma outcomes by serving as a more specific metric of macrophage content compared with uncorrected T1 and SWI techniques.

Diagnostic impact of preoperative corticosteroids in primary central nervous system lymphoma

PURPOSE

High dose corticosteroids are an effective tool for rapidly alleviating neurologic symptoms caused by intracranial mass lesions. However, there is concern that preoperative corticosteroids limit the ability to obtain a definitive pathologic diagnosis, particularly if imaging features suggest primary central nervous system lymphoma (PCNSL).

METHODS

To explore the impact of preoperative corticosteroids in newly diagnosed PCNSL patients, from 2009 to 2018 treated at our institution.

RESULTS

We identified 54 patients; 18 had received corticosteroids prior to biopsy or resection. Only in one case did the patient have a prior non-diagnostic biopsy, requiring a second procedure. The cumulative doses of preoperative dexamethasone ranged from 4 mg to 120 mg (mean 32 mg, median 24 mg), given over 1-14 days (mean 2 days, median 1 day), and the majority had received corticosteroids for only 1-2 days. There was a trend for a larger diameter of lesional T1 contrast enhancement for patients who received steroids (39 mm vs. 34 mm, p = 0.11). In this series of cases with pathologically and clinically proven PCNSL, preoperative corticosteroids had been given in a third of cases, suggesting that they may be given for symptomatic relief without compromising pathologic diagnosis.

CONCLUSIONS

Despite the commonly held tenet that preoperative corticosteroids can obscure the pathologic diagnosis in PCNSL, this is likely not the case in the majority of patients who receive a short course preoperatively. Obtaining a second stereotactic scan to confirm continued presence of the lesion prior to tissue sampling may also mitigate these concerns.

P1026Risk factors for the occurrence of stroke after atrial fibrillation ablation

Background

Risk factors for the occurrence of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated. Our aim was to assess incidence of ES during long-term follow-up following AF ablation and to identify predicting factors associated with post-ablation ES.

Methods

We enrolled patients who experienced ES after AF ablation and body mass index-matched controls from AF ablation registries. Epicardial adipose tissue (EAT) was assessed using multislice computed tomography prior to ablation.

Results

A total of 3,464 patients who underwent AF ablation were recruited. During a mean follow-up of 47.2 months, ES occurred in 47 patients (1.36%) with a mean CHA2DS2-VAS score of 2.15 and overall incidence of ES was 0.34 per 100 patients/year. Compared with control group (n=190), ES group had more higher prior thromboembolic event and AF recurrence rates, larger LA size, lower creatinine clearance rate (CCr), and greater total and periatrial EAT volumes although no differences in AF type, CHA2DS2-VASc score, ablation extent, and anti-thrombotics use were found. On multivariate regression analysis, a prior history of thromboembolism, CCr, and periatrial EAT volume were independently associated with ES occurrence after AF ablation.

Cox regression analysis Risk factor Univariate Multivariate HR (95% CI) p value HR (95% CI) p value Age 1.017 (0.984–1.051) 0.31 Prior thromboembolism 2.488 (1.134–5.460) 0.023 2.916 (1.178–7.219) 0.021 CHA2DS2-VASc score 1.139 (0.899–1.445) 0.282 CCr 0.984 (0.970–0.999) 0.038 0.982 (0.996–0.998) 0.029 LA diameter (mm) 1.070 (1.012–1.130) 0.017 1.072 (0.999–1.150) 0.054 EAT_total (ml) 1.020 (1.010–1.029) <0.001 1.008 (0.993–1.023) 0.297 EAT_periatrial (ml) 1.085 (1.045–1.126) <0.001 1.065 (1.005–1.128) 0.032 PVI + additional ablation 0.846 (0.460–1.557) 0.592 No anticoagulant use 0.651 (0.346–1.226) 0.184 Recurrence 2.011 (1.007–4.013) 0.048 1.240 (0.551–2.793) 0.603 CCr, creatinine clearance rate; EAT, epicardial adipose tissue; LA, left atrium; PVI, pulmonary vein isolation.

K-M curve for stroke-free survival

Conclusions

Incidence of ES after AF ablation was lower than expected rate based on CHA2DS2-VASc score even though anticoagulants use was limited. Periatrial EAT volume, a prior thromboembolism event, and CCr were independent factors in predicting ES irrespective of AF recurrence and CHA2DS2-VASc score in patients who underwent AF ablation.

[Clinical analysis of 555 outpatients with hand, foot and mouth diseases caused by different enteroviruses]

Objective: To study the clinical characteristics of outpatients with hand, foot and mouth disease (HFMD) caused by different serotypes of enteroviruses. Methods: This was a prospective study. From February 2017 to March 2018, 563 outpatients with HFMD were enrolled by systematic sampling in the Department of Infectious Diseases, Henan Children's Hospital. Throat swabs were collected to determine the serotypes via PCR. Demographic, clinical, and laboratory data were collected by standard questionnaire. All cases were followed up twice at 2 and 9 weeks after the initial outpatient visit through telephone interview. A total of 563 cases were enrolled and 555 (98.6%) cases were positive for human enteroviruses, including 338 (60.9%) males. Analyses were stratified by enterovirus serotypes, Chi square test or Fisher's exact test, Rank sum test was used for comparison among different groups. Results: The age of 555 cases was 24.2 (16.4, 41.3) months. Among them 44.0% (224 cases) were identified as coxsackievirus (CV)-A6, while 189 cases, 35 cases, 14 cases and 73 cases were identified as CV-A16, enterovirus (EV)-A71, CV-A10 and other serotypes, respectively. Fever (≥37.5 ℃) was present in 51.4% (285/555) of laboratory confirmed cases. The proportions of fever in cases of CV-A6 (68.9%(168/244)) and CV-A10 (12/14) were significantly higher than those in cases of CV-A16 (31.7%(60/189),χ(2)=57.344,14.313,both P=0.000), other serotypes (43.8%(32/73),χ(2)=15.101 and 8.242, P=0.000 and 0.004) and EV-A71 (37.1%(13/35), χ(2)=13.506 and 9.441, P=0.000 and 0.002) respectively. There was no significant difference between CV-A6 and CV-A10 in presentation of fever (χ(2)=1.785, P=0.182). There were 359 cases (64.7%) with eruptions in mouth, hands, feet and buttocks. Cases infected with EV-A71 had the highest proportions (74.3%(26/35)) of rash emerging simultaneously in mouth, hands, feet, and buttocks. The proportion in cases of CV-A16, CV-A6, CVA10 and other serotype were 73.5% (139/189), 61.9% (151/244), 7/14 and 49.3% (36/73), respectively. The proportion of rash on other parts of body, such as face, limbs or torso in cases infected with CV-A6 (16.8% (41/244)) was the higherest and the proportion in cases of CV-A16, EV-A71, CV-A10 or other serotypes were 8.5% (16/189) , 5.7% (2/35) , 1/14, 6.8% (5/73) , respectively. None of these cases developed serious complications. Desquamation occurred in 45.5% (179/393) cases 7.5 (5.0, 9.0) days after disease onset and 13.5% (53/393) cases showed onychomadesis 31.0 (18.0, 33.5) days after disease onset. The proportion of desquamation and onychomadesis associated with CV-A6 (64.2% (95/148) and 31.8% (47/148)) was significantly higher than CV-A16 (31.8% (49/154) and 1.3% (2/154), χ(2)=33.601 and 52.482, both P=0.000) and other serotypes (38.0%(19/50) and 6.0%(3/50),χ(2)=10.236 and 12.988, P=0.001 and 0.000). Desquamation appeared more in cases of CV-A6 than in cases of CV-A10 (2/11,χ(2)=9.386, P=0.002), with the proportion of onychomadesis higher in CV-A6 than in EV-A71 (3.3% (1/30),χ(2)=11.088, P=0.001). Conclusion: Clinical manifestation such as fever, rash emerging parts, desquamation and onychomadesis are different among outpatient HFMD cases infected with CV-A16, CV-A6, EV-A71, CV-A10 and other enteroviruses.

Novel signal peptides improve the secretion of recombinant Staphylococcus aureus Alpha toxinH35L in Escherichia coli

Secretion of heterologous proteins into Escherichia coli cell culture medium offers significant advantages for downstream processing over production as inclusion bodies; including cost and time savings, and reduction of endotoxin. Signal peptides play an important role in targeting proteins for translocation across the cytoplasmic membrane to the periplasmic space and release into culture medium during the secretion process. Alpha toxin_H35L (AT_H35L) was selected as an antigen for vaccine development against Staphylococcus aureus infections. It was successfully secreted into culture medium of E. coli by using bacterial signal peptides linked to the N-terminus of the protein. In order to improve the level of secreted AT_H35L, we designed a series of novel signal peptides by swapping individual domains of modifying dsbA and pelB signal peptides and tested them in a fed-batch fermentation process. The data showed that some of the modified signal peptides improved the secretion efficiency of AT_H35L compared with E. coli signal peptides from dsbA, pelB and phoA proteins. Indeed, one of the novel signal peptides improved the yield of secreted AT_H35L by 3.5-fold in a fed-batch fermentation process and at the same time maintained processing at the expected site for signal peptide cleavage. Potentially, these new novel signal peptides can be used to improve the secretion efficiency of other heterologous proteins in E. coli. Furthermore, analysis of the synthetic signal peptide amino acid sequences provides some insight into the sequence features within the signal peptide that influence secretion efficiency.

Depression, Impulse Control Disorder, and Life Style According to Smartphone Addiction

We examined depression, impulse control disorder, and life style by degree of smartphone addiction. Chi-square tests and ANOVA were used to identify significant variables. CART was used to generate a decision making diagram of variables affecting smartphone addiction. The severe smartphone addiction group had rates of depression and impulse control disorder than the initial smartphone group.

HMGB1 in the pathogenesis of ultraviolet-induced ocular surface inflammation

High-mobility group box 1 (HMGB1) functions as a transcription-enhancing nuclear protein as well as a crucial cytokine that regulates inflammation. This study demonstrated that secretion of HMGB1 due to ultraviolet (UV) radiation inducing ocular surface inflammation-mediated reactive oxygen species (ROS) production. After treating conjunctival epithelial cells with UV radiation, HMGB1 was translocated from the nucleus to the cytoplasm and then eventually to the extracellular space. HMGB1 played a crucial role in UV-induced conjunctival neutrophil infiltration, which subsided when mice were pretreated with the HMGB1 inhibitors soluble receptor for advanced glycation endproducts (sRAGEs) and HMGB1 A box protein. In case of using ROS quencher, there was decrease in UV-induced HMGB1 secretion in conjunctival epithelial cells and mice. Considering that UV-induced chronic inflammation causes ocular surface change as pterygium, we have confirmed high HMGB1 translocation and ROS expression in human pterygium. Our findings therefore revealed a previously unknown mechanism of UV-induced ocular inflammation related to ROS and HMGB1 suggesting a new medical therapeutic target.

Mating system patterns of natural populations of Pinus koraiensis along its post-glacial colonization route in northeastern China

To understand the genetic mechanisms underlying the endangerment of Pinus koraiensis, we studied the mating system of 49 families of this species in 3 natural populations along its post-glacial colonization route across ~1500 km in northeastern China using the chloroplast simple sequence repeat technique. We analyzed 11 polymorphic loci with clear and repeating bands, and we calculated the multi-locus outcrossing rate (tm), single-locus outcrossing rate, inbreeding index, and fixation index (F). Intra-population variation was not observed, but a large inter-population variation was observed in the outcrossing rate, and the tm increased from 0.767 (the south population) to 0.962 (the north population) along the post-glacial colonization route. The tm values within a population did not change with time over 2 consecutive years. The F values for the 3 populations were <0, which indicates an excess of heterozygotes. The mean effective number of alleles, Shannon diversity index, and Nei's genetic diversity index did not show a south-north pattern. The north population had the highest outcrossing rate but the lowest genetic diversity. The average genetic differentiation of P. koraiensis populations was 0.1251, which was within the average range of woody plants with outcrossing and wind pollination. This study suggests that the current endangerment of P. koraiensis is not related to its genetic structure; perhaps it is mainly caused by man-made and natural disturbances such as deforestation and fire. Therefore, reducing disturbances and enhancing habitats, rather than the genetic aspects, play more important roles in the long-term protection of P. koraiensis.

Extracellular visfatin activates gluconeogenesis in HepG2 cells through the classical PKA/CREB-dependent pathway

Adipokines reportedly affect hepatic gluconeogenesis, and the adipokine visfatin is known to be related to insulin resistance and type 2 diabetes. However, whether visfatin contributes to hepatic gluconeogenesis remains unclear. Visfatin, also known as nicotinamide phosphoribosyltransferase (NAMPT), modulates sirtuin1 (SIRT1) through the regulation of nicotinamide adenine dinucleotide (NAD). Therefore, we investigated the effect of extracellular visfatin on glucose production in HepG2 cells, and evaluated whether extracellular visfatin affects hepatic gluconeogenesis via an NAD+-SIRT1-dependent pathway. Treatment with visfatin significantly increased glucose production and the mRNA expression and protein levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in HepG2 cells in a time- and concentration-dependent manner. Knockdown of SIRT1 had no remarkable effect on the induction of gluconeogenesis by visfatin. Subsequently, we evaluated if extracellular visfatin stimulates the production of gluconeogenic enzymes through the classical protein kinase A (PKA)/cyclic AMP-responsive element (CRE)-binding protein (CREB)-dependent process. The phosphorylation of CREB and PKA increased significantly in HepG2 cells treated with visfatin. Additionally, knockdown of CREB and PKA inhibited visfatin-induced gluconeogenesis in HepG2 cells. In summary, extracellular visfatin modulates glucose production in HepG2 cells through the PKA/CREB pathway, rather than via SIRT1 signaling.

Photochemically crosslinked collagen annulus plug: a potential solution solving the leakage problem of cell-based therapies for disc degeneration

Intra-disc injection of mesenchymal stem cells (MSCs) to treat disc degeneration may lead to unfavorable complications, particularly osteophyte formation. Development of an effective method to block the injection portal, prevent the leakage of injected cells and materials and, hence, prevent osteophyte formation is of the utmost importance before MSC-based therapies can be applied in a clinical setting. Here we seek to alleviate the cell leakage problem and the associated complication osteophyte formation by developing an injectable annulus plug to block the injection portal during intra-disc delivery. Specifically, we fabricated a needle-shaped collagen plug by photochemical crosslinking and successfully delivered it intra-discally, in association with MSCs in collagen microsphere carriers, using a custom-made delivery device. The mechanical performance of the plug and its effectiveness in reducing cell leakage were evaluated ex vivo under compression and in torsion push-out tests. The results demonstrate that the plug survived physiologically relevant loadings and significantly reduced leakage and enhanced retention of the injected materials. Finally, a pilot in vivo study in rabbits was conducted to evaluate the performance of the plug. Microcomputed tomography imaging and histology revealed that the plug significantly reduced osteophyte formation. This work suggests the potential of the annulus plug as an adjunct or annulus closure device for intra-disc delivery of cells and materials.

Does Near-Infrared Spectroscopy Provide an Early Warning of Low Haematocrit following the Initiation of Hypothermic Cardiopulmonary Bypass in Cardiac Surgery?

This study investigated 151 patients undergoing cardiac surgery to determine whether measurement of regional cerebral oxygen saturation (rScO2) using near-infrared spectroscopy (NIRS) can indicate a low haematocrit after initiation of hypothermic cardiopulmonary bypass (CPB). Haematocrit, rScO2, haemoglobin level, arterial partial pressures of carbon dioxide and oxygen, systemic blood pressure, and nasopharyngeal and rectal temperatures were determined 5 min after the initial administration of heparin for CPB and 90 s after completion of the first cardioplegic solution injection. Immediately after initiation of hypothermic CPB, rScO2, haemoglobin and haematocrit values were significantly lower than those before CPB. No significant correlations were found between the change in haematocrit and changes in left, right and mean rScO2; thus, changes in rScO2 before and after initiation of hypothermic CPB did not reflect changes in haematocrit values. This indicates that NIRS cannot provide early warning of a low haematocrit immediately after initiation of hypothermic CPB in cardiac surgery.

Identification of 11 novel mutations in 49 Korean patients with mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is a rare lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS). As MPS II is X-linked, patients are usually males with heterogeneous mutations ranging from point mutations to gross deletions and recombination. In 2003, we reported a mutation analysis of 25 patients with MPS II. In this study, 31 mutations in another 49 Korean patients (45 families) with MPS II are reported: 12 missense, nine deletions, four splicing, two nonsense, two insertions, one deletion/insertion, and IDS-IDS2 recombination mutations. Among these mutations, 11 were novel ones (4 missense mutations: Ser61Pro, Pro97Arg, Pro228Ala, and Pro261Ala; 5 deletions: c.344delA, c.420delG, c.768delT, c.1112delC and c.1402delC; 1 deletion/insertion: c.1222delinsTA; and 1 insertion mutation: c.359_360insATCC). The IDS-IDS2 recombination mutations were most frequently observed; all patients with this mutation had the severe MPS II phenotype. However, most of the patients (5/7) with the G374G splicing mutation had an attenuated phenotype, except for two sibling cases with the severe phenotype. Except for a few recurrent mutations such as the G374G, R443X, L522P, and recombination mutations, each patient had a unique individual mutation. Therefore, careful interpretation of genotype-phenotype correlations is warranted.

Mutational analysis of the latency-associated nuclear antigen DNA-binding domain of Kaposi's sarcoma-associated herpesvirus reveals structural conservation among gammaherpesvirus origin-binding proteins

The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus functions as an origin-binding protein (OBP) and transcriptional regulator. LANA binds the terminal repeats via the C-terminal DNA-binding domain (DBD) to support latent DNA replication. To date, the structure of LANA has not been solved. Sequence alignments among OBPs of gammaherpesviruses have revealed that the C terminus of LANA is structurally related to EBNA1, the OBP of Epstein-Barr virus. Based on secondary structure predictions for LANA(DBD) and published structures of EBNA1(DBD), this study used bioinformatics tools to model a putative structure for LANA(DBD) bound to DNA. To validate the predicted model, 38 mutants targeting the most conserved motifs, namely three alpha-helices and a conserved proline loop, were constructed and functionally tested. In agreement with data for EBNA1, residues in helices 1 and 2 mainly contributed to sequence-specific DNA binding and replication activity, whilst mutations in helix 3 affected replication activity and multimer formation. Additionally, several mutants were isolated with discordant phenotypes, which may aid further studies into LANA function. In summary, these data suggest that the secondary and tertiary structures of LANA and EBNA1 DBDs are conserved and are critical for (i) sequence-specific DNA binding, (ii) multimer formation, (iii) LANA-dependent transcriptional repression, and (iv) DNA replication.

Simulation on combined rapid gravity filtration and backwash models

Combined rapid gravity filtration and backwash models have been applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that an optimum air flow rate exists to maximise particle removal efficiency in the backwash operation for a certain backwash system. The simulation of combined rapid gravity filtration and backwash models suggests that the filter should not be completely cleaned up in the backwash and a certain amount of particles retained on filter grains after backwash can be beneficial for subsequent filtration runs. This is consistent with the experimental results in the literature.

Simulation of combined rapid gravity filtration and backwash models

Combined rapid gravity filtration and backwash models are applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that air flow rate can be optimised to maximise particle removal efficiency in the backwash for a particular system. The simulation of combined rapid gravity filtration and backwash models suggests that efficient backwash operation is essential for maintaining the life time of a filter. However, the filter is not advised to be completely cleaned up in the backwash and the particles retained on filter grains after the backwash can be beneficial for subsequent filtration runs.

Monte Carlo simulation of the photon beam characteristics from medical linear accelerators

The MCNPX code has been employed on a personal computer to calculate the dosimetric characteristics of the photon beams from the 6 MV Siemens MX2 and the 10 MV Varian Clinac 2100C linear accelerators. A model of the treatment head includes the major geometric structure within the beam path. The model was used to calculate the energy spectra of the photon beam, percentage depth dose and the dose profiles. The accuracy of the calculated results is examined by comparing them with the measured dose distributions for the two machines. The computed and measured depth dose curves agree to within 2% for all the depths beyond the build-up region for both treatment machines. The calculations agree to within 2% of the measured profiles within the 100-50% dose level. It has been found that the MCNPX code is an effective tool for simulating the clinical photon beam.

Expression and characterization of a novel enantioselective lipase from Acinetobacter species SY-01

A novel lipase gene, lipase A, of Acinetobacter species SY-01 (A. species SY-01) was cloned, sequenced, and expressed in Bacillus subtilis 168. The deduced amino acid (aa) sequences for the lipase A and its chaperone, lipase-specific chaperone, were found to encode mature proteins of 339 aa (37.2 kDa) and 347 aa (38.1 kDa), respectively. The aa sequence of lipase A and lipase-specific chaperone shared high homology 82 and 67% identity with the lipase A and the lipase B of A. species RAG-1. This new lipase was defined as a group I Proteobacterial lipase family. The expressed lipase A was purified through sequential treatment with Q-Sepharose, Resource Q, and Superdex-S75 columns. The maximal activity was observed at 50 degrees C for hydrolysis of p-nitrophenyl monoesters and found to be stable at pH 9-11, with optimal activity at pH 10. Lipase A hydrolyzed wide range of fatty acid esters of p-nitrophenyl, but preferentially hydrolyzed short length acyl chains (C2 and C4). Moreover, lipase A from A. species SY-01 catalyzed hydrolysis of the two acetate isomers of cis-(+/-)-2-(bromomethyl)-2-(2,4-dichloro phenyl)-1,3-dioxolane-4-methyl acetate, an intermediate required for the synthesis of Itraconazole which was an anti-fungal drug, at different rate and yielded cis-(-)-isomer in 81.5% conversion with 91.9% enantiomeric excess.

The development of fetal surgery

The history of fetal surgery features an absolute dependency upon the possibility of diagnosis before birth. Powerful new imaging methods, the techniques of sampling amniotic fluid and fetal tissue, and modern molecular genetics for the prenatal diagnosis of various congenital diseases have removed the veil of secrecy from the fetus. Even though most prenatally detected congenital malformations can be managed after maternal transport, a few simple anatomic defects require fetal surgery, albeit with predictably poor results. The understanding of intrauterine physiology and pathophysiology in several congenital malformations has been worked out in animal model study, and the natural history of congenital defects revealed by prenatal observations on human fetuses. Selection criteria for intrauterine intervention have been developed. Over the last two decades, surgical techniques for open and endoscopic fetal surgery have been defined and anesthesia and tocolysis for fetal surgery improved. As we enter the 21st century, this field of surgery will surely expand.

The structural and functional organization of the yeast mediator complex

The Mediator complex of Saccharomyces cerevisiae is required for diverse aspects of transcription by RNA polymerase II (pol II). Mediator is composed of two functionally distinct subcomplexes, Rgr1 and Srb4. To identify the structures and functions of each subcomplex, we expressed recombinant proteins for each subunit and assayed their interactions with each other and with basal transcription proteins. The Rgr1 subcomplex is composed of the Gal11 module, which binds activators, and the Med9/10 module. The Med9/10 module is required for both transcriptional activation and repression, and these activities appear to be carried out by two submodules. Proteins in the Med9 submodule interact physically and genetically with Srb10/11, suggesting that the Med9 submodule mediates the repression of pol II. Purified recombinant Srb4 subcomplex stimulated basal transcription of pol II but had little effect on activated transcription and phosphorylation of the C-terminal domain of the Rpb1 subunit of pol II. Both subcomplexes of Mediator interacted with a distinct set of basal transcription factors and pol II. The modular organization of Mediator and the associated functions suggest that the Mediator complex may recruit and/or stabilize the preinitiation complex through several points of contact with transcriptional regulators and basal transcription factors.

Med9/Cse2 and Gal11 modules are required for transcriptional repression of distinct group of genes

The yeast Mediator is composed of two subcomplexes, Rgr1 and Srb4, known to be required for diverse aspects of transcriptional regulation; however, their structural and functional organizations have not yet been deciphered in detail. Biochemical analyses designed to determine the subunit composition of the Rgr1 subcomplex revealed that the regulator-interacting subcomplex has a modular structure and is composed of the Gal11, Med9/Cse2, and Med10/Nut2 modules. Genome-wide gene expression and Northern analyses performed in the presence or absence of the various Mediator modules revealed a distinct requirement for the Gal11, Med9/Cse2, and Med10/Nut2 modules in transcriptional repression as well as activation. GST pull-down analysis revealed that the transcriptional repressor Tup1 binds to distinct but overlapping regions of the Gal11 module that were shown previously to be transcriptional activator binding sites. These data suggest that competition between transcriptional activators and repressors for a common binding site in the Mediator and distinct conformational changes in the Mediator induced by repressor binding may underlie the mechanism of transcriptional repression in eukaryotes.

Biliary atresia associated with meconium peritonitis caused by perforation of small bowel atresia

BACKGROUND/PURPOSE

This report describes our experiences with 5 cases of biliary atresia associated with meconium peritonitis caused by perforation of small bowel atresia.

METHODS

A review of medical records was undertaken in an effort to recognize cases of biliary atresia associated with meconium peritonitis.

RESULTS

Five patients of 171 with biliary atresia (2.9%) were detected to have meconium peritonitis caused by perforation of small bowel atresia. The biliary atresia was not suspected during the initial operation for meconium peritonitis. Total parenteral nutrition (TPN) made it difficult to make an early differential diagnosis of biliary atresia because of the presence of TPN-associated cholestatic jaundice, and the Roux-en-Y limb used for hepatic portoenterostomy could not be made long enough to prevent cholangitis caused by preexisting short bowel. The main complications were severe, intractable cholangitis, short bowel syndrome with malnutrition; TPN-associated liver injury; and wound problems. Two patients died of ascending cholangitis, 1 patient of liver failure that was exacerbated by TPN-associated liver injury, and 1 patient is awaiting a liver transplant. Only 1 patient is in good health, being anicteric and showing normal growth and development.

CONCLUSIONS

Biliary atresia is evidently closely associated with meconium peritonitis caused by perforation of small bowel atresia. The management of these patients is more difficult than that of patients with the usual form of biliary atresia, because of the necessity for a long period of TPN and the combined short bowel syndrome. The ideal management of these conditions has yet to be determined.

Fistula-in-ano in infants: is nonoperative management effective?

PURPOSE

Recently, a number of studies have reported positive results from the nonoperative management of fistula-in-ano in infancy, although it has not been of use in all patients. The purpose of this study was to discern the effective treatment methods of fistula-in-ano in infants.

METHODS

A retrospective review was done of 310 children who required operative management for fistula-in-ano or perianal abscess between January 1991 and July 2000. Eighteen patients displayed an onset of symptoms at less than 1 year of age and a duration of symptoms longer than 12 months. The authors analyzed these patients' medical records.

RESULTS

All patients were boys. The mean duration of the symptoms was 26.6 +/- 27.5 months. Fourteen patients had shown an onset of symptoms at less than 6 months of age. The longest duration was 10 years. The patients showed conservative periods of over 12 months because their parents did not want them to undergo surgery. The disease in these patients followed 2 patterns. One (6 patients) was an onset of symptoms followed by a silent fistula-in-ano state. The other (12 patients) was an onset of symptoms followed by an intermittent relapse of inflammation. All patients underwent fistulotomy, and none of them had recurrent fistula during the follow-up period.

CONCLUSIONS

Although the advantages of a nonoperative management of fistula-in-ano in infants include the avoidance of general anesthesia and surgical intervention, the lesions cannot be cured by a period of conservation. Surgical management is more effective in respect to the time factor.

Molecular cloning and characterization of thermostable DNA ligase from Aquifex pyrophilus, a hyperthermophilic bacterium

A DNA ligase gene from the hyperthermophilic bacterium Aquifex pyrophilus (Ap) was cloned and sequenced. An open reading frame of 2,157 bp that codes for a 82-kDa protein showed 40%-60% homology with a series of NAD+-dependent DNA ligases from different organisms. The recombinant enzyme Ap DNA ligase expressed in Escherichia coli was purified to homogeneity and characterized. The activity of Ap DNA ligase gradually increased in proportion to the concentration of monovalent salt up to 200 mM NaCl, 150 mM KCl, 200 mM NH4Cl, and 350 mM potassium glutamate. The optimum temperature and pH of Ap DNA ligase were greater than 65 degrees C and 8.0-8.6, respectively, for nick-closing activity. More than 75% of the ligation activity was retained after incubation at 95 degrees C for 60 min, whereas the half-lives of Thermus aquaticus and Escherichia coli DNA ligases at 95 degrees C were < or =15 min and 5 min, respectively. Thermostable Ap DNA ligase was applied to repeat expansion detection (RED) and could be a useful enzyme in DNA diagnostics.

Characterization of an oxygen-dependent inducible promoter, the nar promoter of Escherichia coli, to utilize in metabolic engineering

The nar promoters, whose transcription is maximally induced under microaerobic conditions in the presence of nitrate ion, were characterized in fed-batch culture to determine whether they can be used for metabolic engineering, by which overall production of valuable chemicals can be increased. For this purpose, we tested whether the expression level of a reporter gene, the lacZ gene from the nar promoter, could be maintained constant throughout the induction period by manipulation of dissolved oxygen (DO) levels at a given nitrate ion concentration. First, E. coli was grown under aerobic conditions (DO 80%) to absorbance at 600 nm (OD(600)) of 35, then the nar promoter was induced by reduction of DO to different levels, combined with different frequencies and duration of alternating microaerobic and aerobic conditions throughout the entire induction period. For a wild-type nar promoter (pMW61) in a mutant host E. coli with a mutation in the narG gene on the chromosome of the host (RK5265), it was possible to maintain production of beta-galactosidase activity per cell (specific beta-galactosidase activity) at a constant rate at 5000, 10,000, 15,000, and 20,000 Miller units, using different combinations of nitrate ion concentrations (0.1%, 0.5%, and 1%) and DO levels. In addition, it was possible to maintain production of specific beta-galactosidase activity at a constant rate at about 10,000 Miller units in the absence of nitrate ion when a nitrate-independent nar promoter (pMW618) in the narL(-) mutant of the W3110 E. coli strain (W3110narL(-)) was used. Based on these results, we conclude that the nar promoter system provides a convenient expression system for metabolic engineering as well as for maximal production of recombinant proteins under conditions of fed-batch culture.

[Anatomical study and clinical application of medial femoral condylar bone flap pedicled with the saphenous vessels]

OBJECTIVE

To investigate a new operative method for repairing nonunion and defect of tibia.

METHODS

First, observe the relation between the joint branches of descending genicular artery and the saphenous branch of descending genicular artery in 10 cadevers. Then the medial femoral condylar bone flap pedicled with the saphenous vessels was prepared in 4 cadavers for simulated purpose. Clinically, two patients with tibial nonunion were treated by transplantation of this pedicled bone flap.

RESULTS

In the 4 simulated operations, the ink which was injected into the femoral artery could be released from the joint branches. And in the clinical operation, the area of the pedicled bone flaps were 5.0 cm x 2.0 cm x 1.5 cm and 4.5 cm x 1.5 cm x 1.5 cm respectively. Followed up for 8 to 12 weeks, the fracture unioned well.

CONCLUSION

This operation is simple and reliable, it is characterised by 1. unnecessary to anastomosis the vessels 2. reliable blood supply 3. high quality of bone flap 4. either bone flap or bone-skin flap can be chosen 5. long vessel pedicle.

In vivo requirement of activator-specific binding targets of mediator

There has been no unequivocal demonstration that the activator binding targets identified in vitro play a key role in transcriptional activation in vivo. To examine whether activator-Mediator interactions are required for gene transcription under physiological conditions, we performed functional analyses with Mediator components that interact specifically with natural yeast activators. Different activators interact with Mediator via distinct binding targets. Deletion of a distinct activator binding region of Mediator completely compromised gene activation in vivo by some, but not all, transcriptional activators. These demonstrate that the activator-specific targets in Mediator are essential for transcriptional activation in living cells, but their requirement was affected by the nature of the activator-DNA interaction and the existence of a postrecruitment activation process.

REP1, a basic helix-loop-helix protein, is required for a branch pathway of phytochrome A signaling in arabidopsis

Phytochromes are primary photoreceptors mediating diverse responses ranging from induction of germination to floral induction in higher plants. We have isolated novel recessive rep1 (reduced phytochrome signaling 1) mutants, which exhibit a long-hypocotyl phenotype only under far-red light but not under red light. Physiological characterization showed that rep1 mutations greatly reduced a subset of phytochrome A-regulated responses, including the inhibition of hypocotyl elongation, cotyledon expansion, modulation of gravitropic growth of hypocotyl, and induction of the CAB (encoding chlorophyll a/b binding protein) gene, without affecting the accumulation of anthocyanin, far-red-preconditioned blocking of greening, induction of germination, and induction of CHS (encoding chalcone synthase) and FNR (encoding ferredoxin-NADP(+) oxidoreductase) genes. These results suggest that REP1 is a positive signaling component, functioning in a branch of the phytochrome A signaling pathway. Molecular cloning and characterization of the REP1 gene revealed that it encodes a light-inducible, putative transcription factor containing the basic helix-loop-helix motif.

Gram-negative bacteria-binding protein, a pattern recognition receptor for lipopolysaccharide and beta-1,3-glucan that mediates the signaling for the induction of innate immune genes in Drosophila melanogaster cells

Pattern recognition receptors, non-clonal immune proteins recognizing common microbial components, are critical for non-self recognition and the subsequent induction of Rel/NF-kappaB-controlled innate immune genes. However, the molecular identities of such receptors are still obscure. Here, we present data showing that Drosophila possesses at least three cDNAs encoding members of the Gram-negative bacteria-binding protein (DGNBP) family, one of which, DGNBP-1, has been characterized. Western blot, flow cytometric, and confocal laser microscopic analyses demonstrate that DGNBP-1 exists in both a soluble and a glycosylphosphatidylinositol-anchored membrane form in culture medium supernatant and on Drosophila immunocompetent cells, respectively. DGNBP-1 has a high affinity to microbial immune elicitors such as lipopolysaccharide (LPS) and beta-1,3-glucan whereas no binding affinity is detected with peptidoglycan, beta-1,4-glucan, or chitin. Importantly, the overexpression of DGNBP-1 in Drosophila immunocompetent cells enhances LPS- and beta-1,3-glucan-induced innate immune gene (NF-kappaB-dependent antimicrobial peptide gene) expression, which can be specifically blocked by pretreatment with anti-DGNBP-1 antibody. These results suggest that DGNBP-1 functions as a pattern recognition receptor for LPS from Gram-negative bacteria and beta-1, 3-glucan from fungi and plays an important role in non-self recognition and the subsequent immune signal transmission for the induction of antimicrobial peptide genes in the Drosophila innate immune system.

Selective involvement of reactive oxygen intermediates in platelet-activating factor-mediated activation of NF-kappaB

Although it has been suggested that some biological activities of platelet-activating factor (PAF) are mediated by, at least in part, reactive oxygen intermediates (ROI), the precise mechanisms underlying the interaction between the two remains to be elucidated. Antioxidants, such as alpha-tocopherol acid succinate, N-acetyl-L-Cysteine, pyrrolidinedithiocarbamate failed to inhibit PAF-induced immediate systemic reactions such as lethality, symptoms of disseminated intravascular coagulation, and histological changes such as pulmonary edema and hemorrhage in renal medullae 10 min following PAF injection. In contrast. antioxidants significantly inhibited both the in vivo and in vitro PAF-induced NF-kappaB activation and NF-kappaB-dependent TNF-alpha expression. The effects of the antioxidants were due to their inhibition of PAF-induced degradation of IkappaBalpha, a protein responsible for keeping NF-kappaB in an inactive form. A protein tyrosine kinase and N-tosyl-L-phenylalanine chloromethyl ketone sensitive serine protease were involved in both PAF- and H2O2-induced NF-kappaB activation. Collectively, these data indicate that the PAF-induced NF-kappaB activation is selectively mediated through the generation of ROI.

Viscosity of Nonionic Polymer/Anionic Surfactant Complexes in Water

The polymer-micelle model, formerly established by Cabane, is revised to develop a new viscosity equation to describe the dependence of dilute solution viscosity on polymer concentration in PEG/SDS aqueous solutions. Two parameters inthe new equation were proposed to characterize the influence of the polymer solution viscosity on the added surfactant. The viscosity data of polyethylene glycol (PEG) solutions containing sodium dodecyl sulfate (SDS) were measured by the Ubbelohde dilution viscometer and the new equation proved to be in good agreement with the experimental data. Copyright 2000 Academic Press.

Behavior of lanthanides in countercurrent chromatography using dihexyl-N,N-diethylcarbamoyl methylene phosphonate as stationary phase

Counter-current chromatography is a real liquid-liquid chromatography. The retention volume of the solute can be calculated from the batch distribution ratio in organic separations. In the separations of metal ion, there are several complex and dissociation reactions involved in the two phases, and the retention volume cannot be always predicted from the batch distribution ratio. A mass transfer model is proposed in this paper and an expression of V(R) is derived. The retention volume of metal ion is determined not only by the batch distribution ratio but also by the mechanism of the extraction reaction. When 25% dihexyl-N,N-diethylcarbamoyl methylenephosphonate in cyclohexane is used as stationary phase and 2.91 mol/l HNO3 as mobile phase, the dynamic distribution ratios obtained from the chromatogram are not equal to but proportional to the batch distribution coefficients. These results are in agreement with the theoretical expression.

Inhibition of mitogen-activated protein kinase by a Drosophila dual-specific phosphatase

The Drosophila extracellular signal-regulated kinase (DERK) mitogen-activated protein kinase (MAPK) is involved in the regulation of multiple differentiation and developmental processes. Tight control of MAPK activity is critical for normal cell behaviour. We identified a novel Drosophila MAPK phosphatase (DMKP) cDNA from the expressed-sequence-tag database and characterized it. Analysis of the nucleotide sequence revealed an open reading frame encoding the 203-amino acid protein, with a calculated molecular mass of 23 kDa, which has a high amino acid sequence similarity with 'VH1-like' dual-specific phosphatases at the broad region near the catalytic sites. The expression of DMKP mRNA occurs from the late larval stages to adulthood in Drosophila development. The recombinant DMKP protein produced in yeast retained its phosphatase activity. When expressed in Schneider cells, DMKP dose-dependently inhibited DERK and Drosophila c-Jun N-terminal kinase activities with high selectivity towards DERK. However, DMKP did not have any affect on Drosophila p38 activity. When DMKP was expressed in yeast, it down-regulated the fus1-lacZ trans-reporter gene of the pheromone MAPK pathway without any significant effect on the high-osmolarity-glycerol-response pathway.

Conformational study of asialo-GM1 (GA1) ganglioside

In order to investigate the significance of preferred conformations of the saccharide for the steric orientation and recognition of glycosphingolipids at the membrane surface, the conformational free energy calculations were carried out on the asialo-GM1 [GA1; beta-D-Gal (1-->3) beta-D-GalNac(1-->4) beta-D-Gal(1-->4) beta-D-Glc-O-ceramide) using a new program CONCARB (CONformational study program for CARBohydrate) in the unhydrated and hydrated states. The overall backbone conformational of GA1 appears to be extended with a little bent at the glycosidic II-III linkage, in which two pyranose rings of Gal(IV)-GalNAc-(III) moiety orient approximately perpendicular to those of Gal(II)-Glc(I) moiety. This is consistent with the structures deduced from high-sensitivity differential scanning calorimetry experiments and the nmr study on GA1. The calculated glycosidic torsion angles of the lowest free energy conformation of GA1 in the hydrated state are in accord with the structures of relevant oligosaccharides deduced from nmr experiments and hard sphere exoanomeric calculations. A comparison of the values of glycosidic torsion angles phi and psi of GA1 and its constituent oligosaccharides indicates that the overall backbone conformation of each oligosaccharide is retained when the oligosaccharide chain becomes longer. This implies that the short-range interactions between the nearest-neighbored saccharides are of significant importance in stabilizing the overall backbone conformation of GA1 in both the unhydrated and hydrated states. The different orientation and hydrogen bonds of hydroxymethyl and hydroxyl groups from one oligosaccharide to another suggest that the medium- and long-range interactions are also of consequence. Hydration seems to affect significantly the confirmation of these groups, but not to perturb remarkably the overall backbone conformation of GA1.

Biliary atresia in neonates and infants: triangular area of high signal intensity in the porta hepatis at T2-weighted MR cholangiography with US and histopathologic correlation

PURPOSE

To correlate a triangular area of high signal intensity in the porta hepatis on T2-weighted magnetic resonance (MR) cholangiograms of biliary atresia with ultrasonographic (US) and histopathologic findings in a portal mass observed during a Kasai procedure.

MATERIALS AND METHODS

Twenty-one consecutive neonates and infants (age range, 13-88 days; mean age, 59 days) with cholestasis underwent US and single-shot MR cholangiography. In 12 patients with biliary atresia diagnosed at histopathologic examination, MR cholangiographic findings in the porta hepatis were correlated with US and histopathologic findings in the portal mass.

RESULTS

At US, eight of the 12 patients had round, linear, or tubular hypoechoic portions within a triangular cord; MR cholangiography revealed a triangular area of high signal intensity confined to the porta hepatis. Histopathologic examination of the portal mass revealed a cystic or cleftlike lesion surrounded by loose myxoid mesenchyme and platelike fetal bile ducts. Neither the large cystic lesion without ductal epithelium nor the small cleftlike lesion with scanty epithelium demonstrated bile staining. Similar areas of high signal intensity were not seen on T2-weighted images in the remaining patients (four with biliary atresia and nine with neonatal hepatitis).

CONCLUSION

In biliary atresia, T2-weighted single-shot MR cholangiography can show a triangular area of high signal intensity in the porta hepatis that may represent cystic dilatation of the fetal bile duct.

Development and characterization of an oxygen-dependent inducible promoter system, the modified nar promoter in a mutant Escherichia coli

A nar promoter system (a modified nar promoter in a mutant host Escherichia coli (pMW618/W3110narL(-))), which is maximally induced under microaerobic conditions, was developed and characterized through batch and fed-batch culture to see whether the modified nar promoter can be used as an oxygen-dependent inducible promoter in the absence of nitrate ion. The modified nar promoter (pMW618) derived by mutations at -10 and -35 regions of the wild-type nar promoter does not require nitrate ion for the full induction, while a mutant host E. coli, W3110narL(-), does not express nitrate-dependent regulatory protein, NARL, from the host chromosome. In this study, it was found from fed-batch culture that the specific beta-galactosidase activity expressed from the lacZ gene fused to the modified nar promoter in the absence of nitrate ion was maximal when E. coli was grown under aerobic conditions (dissolved oxygen (DO) at 80%) to absorbance at 600 nm (OD(600)) of 35, and then the modified nar promoter was induced by lowering DO to 1-2% with alternating microaerobic and aerobic conditions. The maximal specific beta-galactosidase activity became 58,000 Miller at OD(600) of 160 with an induction ratio of 20. On the basis of these results, we conclude that the modified nar promoter system (pMW618/W3110narL(-)), requiring only reduction of DO for the full induction, provides a convenient and effective high-level expression system under conditions of fed-batch culture.

Lipopolysaccharide-activated kinase, an essential component for the induction of the antimicrobial peptide genes in Drosophila melanogaster cells

Eukaryotic organisms use a similar Rel/NF-kappaB signaling cascade for the induction of innate immune genes. In Drosophila, lipopolysaccharide (LPS) signal-induced activation of the Rel/NF-kappaB family transcription factors is an essential step in the transcriptional activation of inducible antimicrobial peptide genes. However, the mechanism by which the LPS-induced signaling pathway proceeds remains largely unknown. Here we have cloned a novel Drosophila LPS-activated kinase (DLAK) that is structurally related to mammalian IkappaB kinases. DLAK is expressed and transiently activated in LPS-responsive Drosophila cells following LPS stimulation. Furthermore, DLAK can interact with Cactus, a Drosophila IkappaB and phosphorylate recombinant Cactus, in vitro. Overexpression of dominant-negative mutant DLAK (DLAK(K50A)) blocks LPS-induced Cactus degradation. DLAK-bound Cactus can be degraded in a LPS signal-dependent fashion, whereas the DLAK(K50A) mutant-bound Cactus is completely resistant to degradation in the presence of LPS. The DLAK(K50A) mutant also inhibits nuclear kappaB binding activity and kappaB-dependent diptericin reporter gene activity in a dose-dependent manner, but the kappaB-dependent diptericin reporter gene activity can be rescued by overexpression of wild type DLAK. Moreover, mRNA analysis of various kappaB-dependent antimicrobial peptide genes shows that LPS inducibility of these genes is greatly impaired in cells overexpressing DLAK(K50A). These results establish that DLAK is a novel LPS-activated kinase, which is an essential signaling component for the induction of antimicrobial peptide genes following LPS treatment in Drosophila cells.

Caenorhabditis elegans mediator complexes are required for developmental-specific transcriptional activation

Mediator proteins are required for transcriptional regulation of most genes in yeast. Mammalian Mediator homologs also function as transcriptional coactivators in vitro; however, their physiological role in gene-specific transcription is not yet known. To determine the role of Mediator proteins in the development of complex organisms, we purified putative Mediator complexes from Caenorhabditis elegans and analyzed their phenotypes in vivo. C. elegans Mediator homologs were assembled into two multiprotein complexes. RNA interference assays showed that the CeMed6, CeMed7, and CeMed10/CeNut2 gene products are required for the expression of developmentally regulated genes, but are dispensable for expression of the ubiquitously expressed genes tested in this study. Therefore, the gene-specific function of Mediator as an integrator of transcriptional regulatory signals is evolutionarily conserved and is essential for C. elegans development.

Genomic structure and ecdysone regulation of the prophenoloxidase 1 gene in the malaria vector Anopheles gambiae

Prophenoloxidase, a melanin-synthesizing enzyme, is considered to be an important arthropod immune protein. In mosquitoes, prophenoloxidase has been shown to be involved in refractory mechanisms against malaria parasites. In our study we used Anopheles gambiae, the most important human malaria vector, to characterize the first arthropod prophenoloxidase gene at the genomic level. The complete nucleotide sequence, including the immediate 5' flanking sequence (-855 bp) of the prophenoloxidase 1 gene, was determined. The gene spans 10 kb and is composed of five exons and four introns coding for a 2.5-kb mRNA. In the 5' flanking sequence, we found several putative regulatory motifs, two of which were identified as ecdysteroid regulatory elements. Electrophoretic mobility gel-shift assays and supershift assays demonstrated that the Aedes aegypti ecdysone receptor/Ultraspiracle nuclear receptor complex, and, seemingly, the endogenous Anopheles gambiae nuclear receptor complex, was able to bind one of the ecdysteroid response elements. Furthermore, 20-hydroxyecdysone stimulation was shown to up-regulate the transcription of the prophenoloxidase 1 gene in an A. gambiae cell line.

Interleukin (IL)-5 downregulates tumor necrosis factor (TNF)-induced eotaxin messenger RNA (mRNA) expression in eosinophils. Induction of eotaxin mRNA by TNF and IL-5 in eosinophils

An eotaxin is a chemoattractant specific for eosinophils that are known to play a role in helminth infection and allergic responses. Although several cellular sources have been reported to produce eotaxin, it would be interesting to know whether eosinophils are able to produce their own eotaxin and participate in recruitment of themselves in response to inflammation. To this end, a cloned eotaxin complementary DNA was transcribed in vitro to use as a probe for detecting eotaxin messenger RNA (mRNA), and eotaxin protein levels were determined by enzyme-linked immunosorbent assay. Eotaxin mRNA was, as analyzed by in situ hybridization, rarely detectable in unstimulated eosinophils, but was strongly induced in eosinophils when stimulated with tumor necrosis factor (TNF). Interleukin (IL)-5, which is known to be a major factor of eosinophil survival in vivo and in vitro, was also able to induce a modest level of eotaxin mRNA but inhibited TNF-induced eotaxin mRNA expression in a dose-response manner. Dexamethasone inhibited TNF-induced eotaxin mRNA expression. This result was consistent with that from reverse transcription/polymerase chain reaction followed by Southern blot analysis. Unlike the little expression of eotaxin mRNA in the absence of stimuli, the measurement of eotaxin protein revealed that a considerable amount of eotaxin protein was constitutively produced in unstimulated eosinophils. Its expression was upregulated by TNF and IL-5 as well. However, the inhibitory effect of IL-5 on TNF-mediated eotaxin protein production was not as pronounced as that on eotaxin mRNA induction. Collectively, these data reflect the complex physiology of eosinophils in the expression of eotaxin gene upon the exposure to their survival and/or death factors.

Gene silencing-mediated resistance in transgenic tobacco plants carrying potato virus Y coat protein gene

Unlike other pathogens, plant viruses are hardly controlled by chemical agents. Potato virus Y (PVY) is distributed around the world, and causes a great loss economically. In an attempt to minimize the damage by viruses, the PVY coat protein (CP) gene was introduced into tobacco by Agrobacterium-mediated transformation. A significant proportion of the transgenic plants displayed resistance to PVY and showed substantially decreased CP transgene expression at both protein and steady-state mRNA levels compared to susceptible transgenic or nontransgenic plants. A resistant plant was selected and self-fertilized for several generations until T4 progenitor lines were obtained. Most of these T4 plants accumulated extremely low levels of CP protein and steady-state mRNA, and exhibited almost complete resistance to PVY. DNA gel blot analysis revealed that the transgenic plants typically had two or three copies of the transgene. These results are characteristic of pathogen-derived resistance, in which the resistance against virus is the consequence of post-transcriptional gene silencing directed by homologous transgenes. To uncover factors that may play roles in gene silencing, sequences in the 3' part of the transcribed region of the CP gene were transcribed in vitro and the RNA fragments were incubated with cell extracts from transgenic plants. A ribonuclease activity was detected that appeared to be specific for this transcript in the PVY-resistant transgenic plants.