AIS-based operational phase identification using Progressive Ablation Feature Selection with machine learning for improving ship emission estimates

The work status of ships' engines and boilers has a significant impact on emission estimates, which are closely related to ships' operational phases. To improve the accuracy of emission estimates, this study proposed a machine learning-based classification model for identifying operational phases. We proposed 12 operational phase relevance features by analyzing motion behavior-related and geospatial characteristics-related features from the Automatic Identification System (AIS) data from the two bulk carriers. The random forest (RF) model showed the best performance in identifying one of the bulk carrier's operational phases among the five machine models, with the accuracy, F1score and Area Under Curve (AUC) of 96.66%, 93.34% and 99.93%, respectively. By adopting the Progressive Ablation Feature Selection (PAFS) method with RF, the number of features was reduced from 12 to 8, and the accuracy (96.38%), F1score (92.70%), and AUC (98.81%) were almost same with that obtained from all 12 features. Additionally, the effectiveness of the RF model was validated on the other bulk carriers. Compared with the traditional algorithms, the RF model showed better performance in ship operational phase identification and improved the average accuracy of NOx emission estimation for the main engine and auxiliary engine by 57.83% and 93.89%, respectively, under different operational phases. These results provide the basis for port traffic management and ship emission control.Implications: A new ship operational phase identification approach was proposed in this study. If the proposed approach is adopted by International Maritime Organization, it will improve the accuracy of ship emission estimates and bring new insights into global shipping greenhouse gas (GHG) emissions and their impact on global change. The port authorities could benefit from the proposed approach, which can be extended to ship types with similar behavior to bulk carriers, such as containers and general cargoes. This can reveal patterns of ship behavior in specific areas, which helps to identify potential collision risks, channel blockages, and other safety issues and take appropriate management measures to ensure the safe operation of the port. The proposed approach can help shipping companies to accurately estimate the GHG emissions of their fleets and to accurately predict carbon tax costs. Base on that, carbon emissions and carbon tax burden can be reduced by adopting corresponding management control measures.

Profile of atmospheric VOC over the Yellow Sea, China: A tale of distribution, constraints, and sources

In the winter of 2018-2019, 75 air samples were collected through four ship-borne measurements in the Yellow Sea (YS) to assess the levels, confinement processes, and source distribution of volatile organic compounds (VOCs). A total of 41 were eventually detected, which mainly were non-methane hydrocarbons (NMHCs), volatile halogenated hydrocarbons (VHCs), oxygenated volatile organic compounds (OVOCs), and volatile organic sulfur compounds (VSCs). Aromatics (31.93 %) and alkenes (11.04 %) in the atmosphere of the YS accounted for a larger proportion of NMHCs compared with the coastal areas. C3-C5 alkanes, propylene, and chloroform exhibited strong latitudinal gradients and opposite latitudinal distributions in the North and South YS, highlighting the strong contribution of regional outflow to YS's atmosphere. The level of Σ41VOCs increased significantly during the heavy pollution period with some chemical monomers detected, which was further enhanced by the emissions from industrial parks near the Liaodong Peninsula and the Shandong Peninsula. Five main VOC sources were identified by the Positive matrix factorization (PMF) model, which were industrial emissions (13.33 %), fuel use and volatilization (6.67 %), Freon R-22 emissions (33.33 %), oil and gas production (20.00 %), and solvent volatilization (26.67 %). These observations revealed the strong causal relationship between coastal air mass transport and the atmosphere in the marginal sea and emphasized that full attention should be paid to the unintentional and unorganized emission of chemical monomers in the industrial process.

A228 WHEN ASCITES & VARICEAL BLEEDING ARE NOT FROM CIRRHOSIS: A CASE OF MUTIPLE ARTERIOPORTAL FISTULAE CAUSING PORTAL HYPERTENSION

Background

Portal hypertension is usually due to increased resistance from cirrhosis. However, pressures can also be elevated due to increased flow.

Aims

To describe a peculiar case of non-cirrhotic portal hypertension.

Methods

A case report and literature review was performed.

Results

A 47-year-old previously well man presented with a 6 month history of rapidly progressive weight loss, ascites and variceal bleed. Workup ruled out common causes of primary liver disease. Initial imaging demonstrated a heterogenous liver, splenomegaly, ascites, patent hepatic/portal veins and multiple poorly defined low-density hepatic lesions with the largest measuring 2.1 cm. Transient elastography was 7.3 kPa (F1-mild fibrosis). At transjugular liver biopsy, hepatic venogram ruled out Budd-Chiari and hepatic vein pressure gradient was normal at 3–4 mmHg. Histology unfortunately showed hemangioma. A percutaneous liver biopsy suggested nodular regenerative hyperplasia, minimal fibrosis and mild cholestasis. Given worsening ascites, hyponatremia and 7 months of rapidly progressive decline, transjugular intrahepatic portosystemic shunt (TIPSS) was inserted. Intra-procedure, portal vein pressure was noted to be 51 mmHg, with a portosystemic gradient of 42 mmHg. Although numerous abdominal CT and MRI did not show AV shunting, ultrasound post-TIPSS showed hepatic pseudoaneurysms & arterioportal fistulae (APF). Direct angiogram showed numerous hepatic pseudoaneurysms and intrahepatic fistulae making embolization impossible. CT showed no evidence of pseudoaneurysms or fistulae outside of the liver. Workup for autoimmune rheumatological diseases and congenital telangiectatic syndromes were negative. Given the high pressures being directed through the new TIPSS, right heart failure is an ongoing concern.

APF are rarely encountered causes of presinusoidal portal hypertension, with communications most commonly arising from the hepatic (65%) & splenic arteries (11%) & the portal vein. Causes include traumatic (28%), iatrogenic (16%), vascular/telangiectatic malformations (15%), tumors (15%), aneurysms (14%) & congenital disease. Endovascular embolization can be used to treat single lesions. In complex cases with mulitple APF, surgery and/or liver transplantation may be required.

Conclusions

We report a rare case of non-cirrhotic portal hypertension due to increased flow rather than increased resistance secondary to APF.

Funding Agencies

None

Rapid Qualitative and Quantitative Analysis of Caffeine and Sodium Benzoate in Annaca by Infrared Spectroscopy

Objective To establish an infrared spectroscopic method for the rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples. Methods Qualitative and quantitative modeling samples were prepared by mixing high-purity caffeine and sodium benzoate. The characteristic absorption peaks of caffeine and sodium benzoate in Annaka samples were determined by analyzing the infrared spectra of the mixed samples. The quantitative model of infrared spectra was established by partial least squares （PLS）. Results By analyzing the infrared spectra of 17 mixed samples of caffeine and sodium benzoate （the purity of caffeine ranges from 10% to 80%）, the characteristic absorption peaks for caffeine were determined to be 1 698, 1 650, 1 237, 972, 743, and 609 cm^-1. The characteristic absorption peaks for sodium benzoate were 1 596, 1 548, 1 406, 845, 708 and 679 cm^-1. When the detection of all characteristic absorption peaks was the positive identification criteria, the positive detection rate of caffeine and sodium benzoate in 48 seized Annaka samples was 100%. The linear range of PLS quantitative model for caffeine was 10%-80%, the coefficient of determination （ R²） was 99.9%, the root mean square error of cross validation （RMSECV） was 0.68%, and the root mean square error of prediction （RMSEP） was 0.91%; the linear range of PLS quantitative model for sodium benzoate was 20%-90%, the R² was 99.9%, the RMSECV was 0.91% and the RMSEP was 1.11%. The results of paired sample t test showed that the differences between the results of high performance liquid chromatography method and infrared spectroscopy method had no statistical significance. The established infrared quantitative method was used to analyze 48 seized Annaka samples, the purity of caffeine was 27.6%-63.1%, and that of sodium benzoate was 36.9%-72.3%. Conclusion The rapid qualitative and quantitative analysis of caffeine and sodium benzoate in Annaka samples by infrared spectroscopy method could improve identification efficiency and reduce determination cost.

Robotic Assisted Transvaginal Notes Hysterectomy

Study Objective

To demonstrate a novel approach to transvaginal natural orifice transluminal endoscopic surgery (vNOTES) hysterectomy with bilateral salpingectomy using robotic assistance

Design

Video presentation of the surgical procedure.

Setting

University hospital.

Patients or Participants

A 34-year-old G2P1011 with one prior cesarean section and myomectomy complained of dysmenorrhea and chronic pelvic pain and requested for the most minimally invasive form of hysterectomy.

Interventions

A robotic-assisted transvaginal hysterectomy with bilateral salpingectomy was performed. The surgery began as a conventional transvaginal hysterectomy. An anterior and posterior colpotomy were performed, as which point, a camera was inserted to improve visibility. This allowed for confirmation of suspected adhesions from the patient's surgical history, most notably present in the anterior cul-de-sac between the bladder and uterus. Wristed instruments of the robot, the monopolar scissors and bipolar grasper, were also placed which enabled better navigation in the narrow surgical space. The remainder of the surgery, including the lysis of the dense adhesions, was completed smoothly with robotic assistance. The vaginal cuff was closed with a continuous running v-loc. The pelvis was inspected upon conclusion of the procedure and hemostasis was observed throughout.

Measurements and Main Results

The surgery was completed in 90 mins without complications. The patient was discharged on the same day. On follow-up, the patient noted that her post-operative pain was significantly less than what she had experienced after her previous myomectomy.

Conclusion

We showed that robotic-assisted NOTES is a novel and feasible option for transvaginal hysterectomy in indicated patients, particularly those with abnormal pathologies such as dense adhesions. In addition to image-guidance, robotic surgery allows for full articulation of instruments required for this surgery, which improves ease and access over other methods like laparoscopic surgery.

Sex-Based Diverse Plaque Microbiota in Children with Severe Caries

Severe early childhood caries (S-ECC) is a multifactorial disease that can lead to suffering and reduced oral health-related quality of life in young children. The bacterial and fungal composition of dental plaque and how children's sex is associated with S-ECC are largely unknown. In this study, V4-16S rRNA and ITS1 rRNA gene amplicon sequencing was used to compare the plaque bacteriome and mycobiome of children <72 mo of age: 40 with S-ECC (15 males, 25 females) and 40 caries-free (19 males, 21 females). Health- and nutrition-related questionnaire data were also investigated. This study aimed to analyze potential sex-based differences in the supragingival plaque microbiota of young children with S-ECC and those caries-free. Behavioral and nutritional habit differences were observed between children with S-ECC and those caries-free and between male and female children. Overall, higher levels of Veillonella dispar, Streptococcus mutans, and other bacterial species were found in the S-ECC group as compared with caries-free controls (P < 0.05). A significant difference in the abundance of Neisseria was observed between males and females with S-ECC (P < .05). Fungal taxonomic analysis showed significantly higher levels of Candida dubliniensis in the plaque of children with S-ECC as compared with those caries-free (P < 0.05), but no differences were observed with Candida albicans (P > 0.05). Significant differences in the relative abundance of Mycosphaerella, Cyberlindnera, and Trichosporon fungal species were also observed between the caries-free and S-ECC groups (P < 0.05). Machine learning analysis revealed the most important bacterial and fungal species for classifying S-ECC versus caries-free. Different patterns of crosstalk between microbial species were observed between male and female children. Our work demonstrates that plaque microbiota and sex may be important determinants for S-ECC and could be factors to consider for inclusion in caries risk assessment tools.

Preparation and mechanical property of poly(ε-caprolactone)-matrix composites containing nano-apatite fillers modified by silane coupling agents

This study aims to improve the tensile strength and elastic modulus of nano-apatite/poly(ε-caprolactone) composites by silane-modification of the nano-apatite fillers. Three silane coupling agents were used to modify the surfaces of nano-apatite particles and composites of silanized apatite and PCL were prepared by a technique incorporating solvent dispersion, melting-blend and hot-pressing. The results showed that the silane coupling agents successfully modified the surfaces of nano-apatite fillers, and the crystallization temperatures of the silanized apatite/PCL composites were the higher than that of the non-silanized control material, although the melting temperature of the composites remained almost unaffected by silanization. The ultimate tensile strength and elastic modulus of the silanized composites reached 22.60 MPa and 1.76 GPa, as a result of the improved interfacial bonding and uniform dispersion of nano-apatite fillers. This study shows that the processing technique and silanization of nano-apatite particles can effectively improve the tensile strength and elastic modulus of nano-apatite/PCL composites.

Chemical constituents of roots ofEpimedium wushanenseand evaluation of their biological activities

Seven flavonoids named diphylloside A, epimedoside A, epimedin C, icariin, epimedoside C, icarisoside A, desmethylanhydroicaritin, as well as the oleanolic acid, were isolated from the roots of Epimedium wushanense for the first time. These flavonoids manifested significant antioxidant activity in vitro. Scavenging effects of two flavonoids were comparable to that of Vitamin C. Antibacterial experiment has shown that the diphylloside A, icarisoside A and desmethylanhydroicaritin have significant activity towards Pseudomonas aeruginosa.

[The expression of PCNA and NOR in carcinogenesis procession of hamster buccal pouch mucosa]

OBJECTIVE

To investigate the expression of proliferating cell nuclear antigen (PCNA) and nucleolar organizer regions (NOR) with the carcinogenesis model of hamster buccal pouch mucosa.

METHODS

48 Syrain hamsters with 6-8 weeks old and 70-80 g weight were selected. The material used for inducing cancer is 0.5% DMBA (7,12-dimethylbenzanthracene) in acetone. 0.5% DMBA was applied in the right buccal pouch of the hamster 3 times a week for 12 weeks. The control received no treatment. The time for collecting specimens was 3, 6, 9 and 12 weeks. The specimens were immediately fixed with 10% formalin, dyed with HE, and then two doctors major in histopathology evaluated with the WHO criterion (1986). The wax of immunohistochemical specimen was cut and placed on the APES pieces of glass, treated with 50 degrees C for 2 hours and preserved under the indoor temperature. The PCNA was examined with the LSAB technique of immunohistochemistry. The company called Zymed provided the MonAb. The positive control was a sample of human inflammatory hyperplastic lymphoma, and the negative was PBS replacing the MonAb. NOR count was determined in a method of silver nitrate staining. The test condition should be at 45 degrees C without light.

RESULTS

1. AgNOR was usually located in the basal-cell layer of normal epithelium, mainly in a single form. High dysplasia was mainly in an aggregated form, however, carcinoma in infiltration appeared to be in a mixed form. 2. PCNA expression was similar to that of the normal control in hyperplastic epithelia (3 weeks) at a moderate level in dysplasia epithelia (6-9 weeks). PCNA expressed highly in squamous cell carcinoma. The expression of the PCNA in line with malignant progress became stronger increasingly. The positive cell was perceivable in all epithelia of high dysplasia.

CONCLUSION

PCNA has been significantly positive and correlative with AgNOR (r = 0.635, P < 0.001), however, the film of PCNA is much clearer and the practical value is greater.

Atrophin-1, the dentato-rubral and pallido-luysian atrophy gene product, interacts with ETO/MTG8 in the nuclear matrix and represses transcription

Dentato-rubral and pallido-luysian atrophy (DRPLA) is one of the family of neurodegenerative diseases caused by expansion of a polyglutamine tract. The drpla gene product, atrophin-1, is widely expressed, has no known function or activity, and is found in both the nuclear and cytoplasmic compartments of neurons. Truncated fragments of atrophin-1 accumulate in neuronal nuclei in a transgenic mouse model of DRPLA, and may underlie the disease phenotype. Using the yeast two-hybrid system, we identified ETO/MTG8, a component of nuclear receptor corepressor complexes, as an atrophin-1-interacting protein. When cotransfected into Neuro-2a cells, atrophin-1 and ETO/MTG8 colocalize in discrete nuclear structures that contain endogenous mSin3A and histone deacetylases. These structures are sodium dodecyl sulfate-soluble and associated with the nuclear matrix. Cotransfection of ETO/MTG8 with atrophin-1 recruits atrophin-1 to the nuclear matrix, while atrophin-1 and ETO/MTG8 cofractionate in nuclear matrix preparations from brains of DRPLA transgenic mice. Furthermore, in a cell transfection-based assay, atrophin-1 represses transcription. Together, these results suggest that atrophin-1 associates with nuclear receptor corepressor complexes and is involved in transcriptional regulation. Emerging links between disease-associated polyglutamine proteins, nuclear receptors, translocation-leukemia proteins, and the nuclear matrix may have important repercussions for the pathobiology of this family of neurodegenerative disorders.

Human huntingtin-associated protein (HAP-1) gene: genomic organisation and an intragenic polymorphism

The huntingtin-associated protein (HAP-1) interacts with the Huntington disease gene product, huntingtin. It is predominantly expressed in the brain and shows an increased affinity for mutant huntingtin. We have sequenced an 18,656bp genomic region encompassing the entire human HAP-1 gene and determined its genomic organisation, with 11 exons spanning 12.1kb. We have also found an intragenic polymorphism within intron 6 of HAP-1. We have recently shown that HAP-1 maps to a region of the genome which has been implicated in a variety of neurological conditions, including progressive supranuclear palsy (PSP), a late-onset atypical parkinsonian disorder. The detailed characterisation of the genomic organisation of HAP-1 and the presence of an intragenic polymorphism will be helpful in evaluating its role in different disorders, using candidate gene approaches.

RegA, iron, and growth phase regulate expression of the Pseudomonas aeruginosa tol-oprL gene cluster

The tol-oprL region in Pseudomonas aeruginosa appears to be involved in pyocin uptake and required for cell viability. The complete nucleotide sequences of the tolQRA and oprL genes as well as the incomplete sequences of tolB and orf2 have been previously reported. In addition, the sequence of a P. aeruginosa iron-regulated gene (pig6) has been described and found to share homology with an open reading frame located upstream of the Escherichia coli tolQRA genes (U. A. Ochsner and M. L. Vasil, Proc. Natl. Acad. Sci. USA 93:4409-4414, 1996). In this study, we cloned the remainder of the P. aeruginosa tol-oprL gene cluster and determined its nucleotide sequence. This cluster was found to consist of seven genes in the order orf1 tolQ tolR tolA tolB oprL orf2. Transcriptional analysis of this gene cluster was performed by detecting the presence of mRNAs spanning adjacent genes as well as by using a promoterless lacZ reporter gene fused to each of the seven genes contained in the tol-oprL locus. The results show that there are three major transcriptional units or operons in this region, orf1-tolQRA, tolB, and oprL-orf2, in contrast to the E. coli tol-pal region, where there are only two operons, orf1-tolQRA and tolB-pal-orf2. Analysis of gene expression indicated that the tol-oprL genes of P. aeruginosa are both iron and growth phase modulated. The first operon, orf1-tolQRA, is iron regulated throughout growth, but iron-regulated expression of tolB and oprL fusions occurs only in late log phase. The expression of the three operons was significantly less repressed by iron in fur mutants than in the wild-type strain, suggesting the involvement of Fur in the iron regulation of all three operons. RegA is a positive yet nonessential regulator of tol-oprL expression.

Nucleotide sequence and thermostability of pND324, a 3.6-kb plasmid from Lactococcus lactis

A 3.6-kb plasmid, designated pND324, was isolated from Lactococcus lactis subsp. lactis LL57-1. Sequence analysis revealed the presence of three open reading frames, rep324, orfX1 and orfX2, which are flanked by two non-coding regions, ori324 and cisE. The minimal replication region of pND324 consists of ori324 and rep324, which is closely related to the lactococcal theta-type replicons of the pWV02/pCI305 family. pND324 was stable at both 30 degrees C and 37 degrees C, whereas derivatives that lack cisE were highly unstable at 37 degrees C, indicating that cisE is essential for thermostability. Sequences that are similar to orfX1 are commonly present in the lactococcal theta-type plasmids. The orfX2 product is homologous to TrfA, a 43-kDa protein of the E. coli theta-type plasmid RK2 required for replication and maintenance. Plasmid deletion and stability analyses showed that orfX2 is involved in the thermostability of pND324. Based on the minimal replication region of pND324, an integrative cloning vector, designated pND421, was constructed. In L. lactis LM0230, cells that carried pND421 integrated into its host chromosomal DNA could be recovered readily following incubation at 37 degrees C for 40 generations. The integrated plasmid was totally stable for at least 100 generations without selection at 30 degrees C.

Nuclear accumulation of truncated atrophin-1 fragments in a transgenic mouse model of DRPLA

Dentatorubral and pallidoluysian atrophy (DRPLA) is a member of a family of progressive neurodegenerative diseases caused by polyglutamine repeat expansion. Transgenic mice expressing full-length human atrophin-1 with 65 consecutive glutamines exhibit ataxia, tremors, abnormal movements, seizures, and premature death. These mice accumulate atrophin-1 immunoreactivity and inclusion bodies in the nuclei of multiple populations of neurons. Subcellular fractionation revealed 120 kDa nuclear fragments of mutant atrophin-1, whose abundance increased with age and phenotypic severity. Brains of DRPLA patients contained apparently identical 120 kDa nuclear fragments. By contrast, mice overexpressing atrophin-1 with 26 glutamines were phenotypically normal and did not accumulate the 120 kDa fragments. We conclude that the evolution of neuropathology in DRPLA involves proteolytic processing of mutant atrophin-1 and nuclear accumulation of truncated fragments.

[The abnormal expression of pRb during DMBA-induced hamster buccal pouch carcinogenesis]

OBJECTIVE

To study the expression and role of pRb in 7,12-dimethylbenzanthracene(DMBA) induced hamster buccal pouch carcinogenesis.

METHODS

DMBA (0.5%) in acetone was applied to the right buccal pouch 3 times per week for up to 12 week. Paraffin-embedded sections were used for pRb immunohistochemical determination (ISAB technipue, polyclonal antibody c-15 for pRb). The density of staining was analysed by rank sum test.

RESULTS

The positive staining of pRb was strong in normal buccal epithelium, no alteration of pRb staining in 3 week (hyperplastic epithelium) and somewhat reduced between 6 and 9 week (dysplastic lesion), but it was marked reduced in 12 week (carcinoma). Statistical analysis found that changes of pRb were associated with stages of carcinogenesis.

CONCLUSION

These results indicate that abnomal expression of Rb gene product could be related to oral carcinogenesis and may serve as a biomarker for supervising oral malignancy.

Intranuclear inclusions and neuritic aggregates in transgenic mice expressing a mutant N-terminal fragment of huntingtin

Huntington's disease (HD) is an inherited, neurodegenerative disorder caused by the expansion of a glutamine repeat in the N-terminus of the huntingtin protein. To gain insight into the pathogenesis of HD, we generated transgenic mice that express a cDNA encoding an N-terminal fragment (171 amino acids) of huntingtin with 82, 44 or 18 glutamines. Mice expressing relatively low steady-state levels of N171 huntingtin with 82 glutamine repeats (N171-82Q) develop behavioral abnormalities, including loss of coordination, tremors, hypokinesis and abnormal gait, before dying prematurely. In mice exhibiting these abnormalities, diffuse nuclear labeling, intranuclear inclusions and neuritic aggregates, all immunoreactive with an antibody to the N-terminus (amino acids 1-17) of huntingtin (AP194), were found in multiple populations of neurons. None of these behavioral or pathological phenotypes were seen in mice expressing N171-18Q. These findings are consistent with the idea that N-terminal fragments of huntingtin with a repeat expansion are toxic to neurons, and that N-terminal fragments are prone to form both intranuclear inclusions and neuritic aggregates.

Involvement of antisense RNA in replication control of the lactococcal plasmid pND324

pND324 belongs to a family of closely related theta-type plasmids from Lactococcus lactis. An antisense RNA, termed countertranscript (ctRNA), was identified which is complementary to the leader sequence of the mRNA that encodes RepB, a protein essential for plasmid replication. When the synthesis of ctRNA was abolished by site-directed mutagenesis within its promoter region, the mutant replicon showed a 1.8-fold increase in copy number. Similar ctRNA promoter sequences are readily identifiable in 12 other published lactococcal theta-type plasmids, suggesting that they all encode a similar ctRNA-mediated regulatory mechanism.

Gene structure and map location of the murine homolog of the Huntington-associated protein, Hap1

Huntington's Disease (HD) is an inherited progressive neurodegenerative disorder associated with a mutation in a gene expressed in both affected and non-affected tissues. The selective neuropathology in HD is thought to be mediated in part through interactions with other proteins including the Huntington Associated Protein, HAP-1, which is predominantly expressed in the brain. We have mapped its murine homolog, Hap1, to mouse Chr 11 (band D), which shares extensive synteny with human Chr 17 including the region 17q21-q22, where the gene for 'frontotemporal dementia and parkinsonism linked to chromosome 17' has bee mapped. In addition, we have sequenced a 21,984 base pair (bp) genomic clone encompassing the entire Hap1 gene. It is organized as 11 exons and flanked by exons from potentially one or more novel genes. At least three Hap1 transcripts (Hap1-A; Hap1-B; Hap1-C) can be formed by alternative splicing at the 3' end of the gene leading to protein isoforms with novel C-termini.

Atrophin-1, the DRPLA gene product, interacts with two families of WW domain-containing proteins

Atrophin-1 contains a polyglutamine repeat, expansion of which is responsible for dentatorubral and pallidoluysian atrophy (DRPLA). The normal function of atrophin-1 is unknown. We have identified five atrophin-1 interacting proteins (AIPs) which bind to atrophin-1 in the vicinity of the polyglutamine tract using the yeast two-hybrid system. Four of the interactions were confirmed using in vitro binding assays. All five interactors contained multiple WW domains. Two are novel. The AIPs can be divided into two distinct classes. AIP1 and AIP3/WWP3 are MAGUK-like multidomain proteins containing a number of protein-protein interaction modules, namely a guanylate kinase-like region, two WW domains, and multiple PDZ domains. AIP2/WWP2, AIP4, and AIP5/WWP1 are highly homologous, each having four WW domains and a HECT domain characteristic of ubiquitin ligases. These interactors are similar to recently isolated huntingtin-interacting proteins, suggesting possible commonality of function between two proteins responsible for very similar diseases.

[Effect of taixian tablet on hamster buccal pouch carcinogenesis]

Eighty syrian hamsters were divided into 4 equal groups. The right buccal pouches of hamsters in group I and group II were painted three times weekly with 0.5% DMBA dissolved in acetone, but the hamsters in group I received 0.45 g Taixian tablet daily by mouth. The animals in group III only received 0.45 g Taixian tablet daily and group IV was control group. After 9, 12 weeks, animals were killed with their pouches excised, and tumors were counted and measured. The results showed; 1. Comparing with group II, the malignant rate of group I was lower after 9 weeks and the tumor volume was smaller after 12 weeks (P < 0.01); 2. It was found histologically many inflammatory cells locating in the epithelial layer and lamina propria of group I after 9 weeks, while only a few inflammatory cells in group II. The high differentiated squamous cell carcinoma could be seen in group I and group II after 12 weeks, but no abnormal changes in cervical lymphnodes and organs (lung, liver, spleen, et al) of all animals in 4 groups. It suggests that Taixian tablet can restrain the development of oral carcinogenesis.

Huntingtin-associated protein 1 (HAP1) binds to a Trio-like polypeptide, with a rac1 guanine nucleotide exchange factor domain

Huntington's disease (HD) occurs when the widely expressed protein huntingtin contains an expanded glutamine repeat. The selective degeneration and neuronal morphologic abnormalities of HD may involve interactions with proteins that bind to huntingtin, such as HAP1. The biological significance of this interaction is unclear because neither HAP1 nor huntingtin have significant homology to known proteins. Therefore, we sought to identify HAP1-binding proteins. Using the yeast two-hybrid system, we isolated a rat cDNA encoding part of a protein that interacts with HAP1, and we confirmed the specificity of this interaction using an in vitro protein-binding assay. We called the protein Duo because it is closely related to the human protein Trio but is shorter. Northern blot analysis indicates brain-specific expression of Duo. Human Duo contains a guanine nucleotide exchange factor (GEF) domain that is likely to be rac1-specific, a pleckstrin homology (PH) domain and spectrin-like repeat units. These data support the hypothesis that huntingtin is involved in vesicle trafficking and cytoskeletal functions, and raise the possibility of a role for huntingtin in the regulation of a ras-related signaling pathway.

Identification and characterization of a mobilizing plasmid, pND300, in Lactococcus lactis M189 and its encoded nisin resistance determinant

A 60 kb conjugative plasmid, pND300, which encodes nisin resistance, was identified in Lactococcus lactis ssp. lactis (L. lactis) M189. pND300 was found to mobilize the transfer of some other plasmids as indicated by the mobilization of plasmids encoding lactose utilization. The nisin resistance determinant from pND300 was initially subcloned on a 12 kb DNA fragment and subsequently reduced to 10.4 kb. Restriction analysis, PCR, Southern hybridization and sequencing illustrated that the nisin resistance of pND300 is very similar to that encoded by the transposon involved in nisin production. pND300 encodes nisR as well as nisK and the recently reported nisF, nisE and nisG, but does not encode nisI. The DNA fragment encoding the nis genes is flanked by IS946 with a copy at each end in reverse orientation. The expression of these nis genes is probably controlled by a putative promoter upstream of nisR, which is composed of the TTGCAA hexanucleotide on the insertion sequence IS946 and the TATAAT sequence 21 bp downstream.