Clinical study on simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy for synchronous colorectal cancer liver metastasis

PURPOSE

This study aimed to analyze the clinical effect of simultaneous resection of liver metastases combined with hyperthermic intraperitoneal chemotherapy (HIPEC) on synchronous colorectal cancer liver metastasis.

METHODS

A total of 144 patients with synchronous colorectal cancer liver metastasis who were admitted to our hospital between January 2018 and January 2019 were randomly assigned into a control group and an intervention group. The patients in the control group received simultaneous resection of liver metastases. The patients in the intervention group obtained simultaneous resection of liver metastases combined with HIPEC. The recent total effective rate of the 2 groups was compared, and the disease control rate of the 2 groups was calculated at 3 months after treatment. The patients were followed up for 3 years. The survival time of the 2 groups was observed and compared. Fasting venous blood was collected from patients in the 2 groups, and the carcinoembryonic antigen (CEA) level was compared. The level of quality of life scale (Short Form 36-item Health Survey) and the occurrence of adverse reactions were compared between the 2 groups.

RESULTS

The R0 complete resection rate in the intervention group was significantly higher than that in the control group (P < .05). The recent total effective rate in the intervention group (87.50%) was significantly higher than that in the control group (59.72%) (P < .05). The negative change of CEA in the intervention group was 72.22%, which was prominently higher than that in the control group of 43.06% (χ2 = 12.542, P < .001). After a 36-month follow-up, the overall survival rate of the observation group was significantly higher than that of the control group (hazard ratio, 2.54; 95% CI, 1.05-5.48; P < .001). The patients in the intervention group had significantly higher life quality scores of health status, social function, emotional function, physical function, and mental health than in the control group (P < .05). There was no significant difference in the incidence of complications between the 2 groups (P > .05). Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were risk factors affecting the occurrence of complications after treatment and were closely correlated with the prognosis and survival of patients (P < .05). Patients with age ≤ 60 years, no preoperative comorbidities, low tumor differentiation, intraoperative blood loss ≤ 150 mL, more experienced surgeons, and complete R0 resection had a longer survival time. Age > 60 years, preoperative comorbidities, moderate and high differentiation of tumors, intraoperative blood loss > 150 mL, and less experienced surgeons were independent risk factors affecting the prognosis of patients with colorectal cancer liver metastases (P < .05), whereas R0 surgery was an independent protective factor for the prognosis (P < .05).

CONCLUSION

In the treatment of synchronous colorectal cancer liver metastases, simultaneous resection of liver metastases in conjunction with HIPEC demonstrated superior efficacy. This approach may potentially extend patient survival and enhance quality of life and deserve to be extensively used in clinical practice.

[Analysis of fast-growing culturable bacteria and pathogenic bacteria in the surface water of the northeast coast of Hainan Island in China]

Objective: To obtain the diversity and abundance of fast-growing bacteria in the surface water of the northeast coast of Hainan Island in China, different cultivation methods were employed. This study also aims to provide a reference for isolating bacterial samples from seawater sources and preventing marine-derived pathogens. Methods: Based on the principles of taxonomic design, surface seawater samples were collected from six locations along the northeast coast of Hainan Island in China in March, June, October, and December 2021. Then, bacterial enrichment was performed based on traditional cultivation methods for Salmonella, Vibrio, Burkholderia pseudomallei, Actinomycetes, and general marine bacteria. After that, bacterial species identification was conducted by 16S rDNA amplicon sequencing and metagenomic sequencing. Results: A total of 1 151 fast-growing cultivable bacteria belonging to 66 genera and 213 species were identified using five different culture protocols. In different cultivation protocols, Bacillus and Klebsiella demonstrated extensive discriminatory advantages and ranked among the top genera in terms of abundance. Protocol 1 had Escherichia, Klebsiella, and Citrobacter as dominant genera. Pathogenic bacteria detected by protocol 1 included Klebsiella pneumoniae and Escherichia coli, with 37 and 29 strains respectively, while Salmonella enterica was uniquely detected with seven isolates. Proteus, Enterococcus, and Providencia were the dominant genera in protocol 2, and Proteus mirabilis was the most abundant pathogenic bacteria detected with 66 isolates. Vibrio cholerae was uniquely detected with six isolates at a higher abundance. Klebsiella, Escherichia, and Acinetobacter were the dominant genera in protocol 3, and Klebsiella pneumoniae was the most abundant pathogenic bacteria detected with 53 isolates, while Acinetobacter nosocomialis was uniquely detected with seven isolates. Vibrio and Pseudoalteromonas were the dominant genera in protocol 4, and they showed advantages in isolating and cultivating Marine-derived Vibrio. Exiguobacterium, Staphylococcus, and Bacillus were the dominant genera in protocol 5. Bacillus cereus and Lactococcus lactis were the most abundant pathogenic bacteria detected with 20 and 15 isolates, respectively, while Lactococcus lactis was uniquely detected at higher abundance. Metagenomic sequencing showed that Klebsiella pneumoniae was significantly dominant with a gene abundance of 51.11%, followed by Alcanivorax sp. at 12.57%. Conclusion: The surface water of the northeast coast of Hainan Island in China exhibits a rich diversity of bacteria, with Klebsiella pneumoniae being highly abundant in the studied area. Different cultivation methods demonstrate distinct selective advantages in culturing bacterial genera and pathogens. Therefore, it is necessary to optimize cultivation conditions for specific marine bacteria.

Regulation of Tumorigenesis in Hepatocellular Carcinoma via the AKT3 Pathway in Cell Lines

BACKGROUND

The estimation of hepatocellular carcinoma (HCC) is tremendously inferior because of the formation of chemoresistance, integrated with essentially increased stemness belongings. At present, the relevance between miR-122 and cancer development was mostly undisclosed with single study reflecting its importance in glioblastoma. Material and Methods. The research here was focused to investigate the task of miR-122 to modulate tumorigenesis in hepatocellular carcinoma by aiming AKT3 in the management of hepatocellular carcinoma stemness and chemosensitivity. The method of QRT-PCR was performed to investigate the aspect of miR-122 and AKT3 in tissue sample and cell lines. The evaluation was done using gain- or loss-of-function in order to retrieve the function of miR-122 in the hepatocellular carcinoma cells, including cell multiplication and stemness effects. The properties of hepatocellular carcinoma were discovered by the development of sphere development, cell feasibility, and the emergence of colony. RNA immunoprecipitation (RIP), luciferase reporter, and the RNA pull down evaluation were conducted to investigate the communication between the miR-122 and AKT3. Therefore, a naked mouse xenograft specimen was set up for the in vivo analysis.

RESULTS

Here, we determined the new role of AKT3 and unmediated target of miR-122. The reimposition of miR-122 appearance in the hepatocellular carcinoma cell lines reduces the levels of AKT3 and also hinders the relocation and expansion of cells by prompting apoptosis. These phenotypes are antitumor in nature and can be retrieved by the reorganization of the AKT3 expression which signals the crucial role of AKT3 in the miR-122 arbitrated HCC modification. The in vivo analysis demonstrated the reimposition of miR-122 entirely obstructing the xenograft expansion to manage tumorigenesis in hepatocellular carcinoma and a prospective remedial entrant for the liver cancer.

CONCLUSION

In this study, it was observed that miR-122 encourages the stemness role of hepatocellular carcinoma and diminishes the chemosensitivity by cleaning the miR-122 in order to initiate the AKT3. The in vivo study reflected the restoration of miR-122 which completely hinders the xenograft growth to regulate the tumorigenesis in the HCC.

Exchange bias and Verwey transition in Fe5C2/Fe3O4 core/shell nanoparticles

This report presents new findings of exchange bias and related structural and magnetic properties in iron carbide/magnetite (Fe₅C₂/Fe₃O₄) core/shell nanoparticles. The exchange bias emerges from an energetic landscape, namely a first-order phase transition-the Verwey transition at 125 K, during which the Fe₃O₄ shell changes from the cubic to monoclinic structure. The phase transition leads to the exchange bias because it results in abrupt changes in magnetocrystalline anisotropy and exchange coupling. Another unique phenomenon identified in this composite system is enhanced magnetic coercivity due to the uniaxial anisotropy of the monoclinic phase. An analysis of the correlations between the observed phenomena is given based on the temperature dependence of the coercivity, the exchange bias field values, and the Verwey transition temperature.

[Serological study of Lyme disease antibody in 2 311 patients with arthritis symptoms in Hainan Province]

Objective: To understand the infectious status of Lyme disease among patients with arthritis symptoms in Hainan Province, and to provide a theoretical basis for prevention and control of Lyme disease. Methods: From 2013 to 2018, sampling surveys had been conducted in medical institutions in 8 cities in Hainan Province(Haikou, Sanya, Danzhou, Dongfang, Wenchang, Qionghai, Qiongzhong, Wuzhishan), 2 311 patients serum samples were collected with arthritis symptoms, and descriptive research were conducted base on the collected clinical data. The Indirect Fluorescent-Antibody Test (IFA) method was used for preliminary screening of Lyme disease antibody, the Western Blot (WB) method was used for IFA positive samples confirmation. Statistical analysis using χ² test. Results: 2 311 serum samples were tested by IFA, and 166 were positive with the positive rate of 7.18%. Further confirmed by WB method, 62 samples were positive, the positive rate of Lyme disease antibody was 2.68%(62/2 311). The positive rate of Lyme disease antibody among patients with arthritis in different regions of Hainan was statistically significant (χ²=40.636,P<0.001), and the positive rate in Qiongzhong city was the highest (8.81%, 14/159). Danzhou's positive rate was the second highest, 5.62%(5/89). Dongfang city had the lowest positive rate (0.51%, 2/394). The positive rates of Lyme disease serum antibody in men and women were 2.79% (33/1 182) and 2.57% (29/1 129), respectively; the positive rates of antibodies between each age groups were in the range of 1.74% to 3.64%. The antibody positive rate of Lyme disease showed no significant difference between gender and age (χ²=0.110,P=0.740 ;χ²=1.938,P=0.747). Conclusion: Patients with arthritis symptoms caused by Borrelia burgdorferi infection were found in 8 cities in Hainan province, but the Lyme disease antibody positive rate was different among cities, with Qiongzhong County being the highest.

Magnetic-field-induced self-assembly of FeCo/CoFe2O4 core/shell nanoparticles with tunable collective magnetic properties

Self-assembly of nanoparticles into ordered patterns is a novel approach to build up new consolidated materials with desired collective physical properties. Herein, nanoparticle assemblies of composition-modulated bimagnetic nanoparticles have been produced via slow evaporation of their colloidal suspension in the absence or presence of magnetic fields. The assemblies obtained in the presence of the magnetic fields exhibit oriented nanoparticle chains in face-centered cubic superlattice structures, compared with the hexagonal closed-packed superlattice obtained without the magnetic field. The oriented structure has an alignment of the easy magnetization axis along the chains. This alignment leads to enhanced intra-superlattice interactions. As a result, the field-induced assembly displays collective magnetic properties with significantly enhanced magnetic anisotropy, remanent magnetization and coercivity. It is also found that the bimagnetic FeCo/CoFe2O4 core/shell nanostructure enhances the intra-particle interaction and thus is beneficial for the growth of oriented assembly of nanoparticles. Furthermore, the collective magnetic behavior is evidenced by the observation of a superferromagnetic-like magnetization relaxation in the ac-susceptibility curves.

MiR-520b inhibits proliferation, migration and invasion in gallbladder carcinoma by targeting RAB22A

INTRODUCTION

Previous studies have reported that miR-520b exhibited inhibitory effects on various human tumors, whereas the effects of miR-520b on gallbladder carcinoma (GBC) have remained unclear. To investigate the effects of miR-520b on GBC progression and reveal the underlying mechanisms, this study was performed.

MATERIAL AND METHODS

MiR-520b and RAB22A mRNA levels were analyzed by quantitative real-time PCR (qPCR). RAB22A protein level was analyzed via Western blot and immunohistochemical (IHC) analysis. The proliferation, colony formation ability, migration and invasion of NOZ cells were measured via MTT, colony formation, wound healing and transwell invasion assay respectively.

RESULTS

MiR-520b expression level was lower in human GBC tissues than that in neighboring normal tissues. MiR-520b mimic repressed NOZ cell proliferation, colony formation ability, migration and invasion, whereas miR-520b inhibitor exhibited opposite effects. Dual luciferase reporter assay confirmed that miR-520b could bind to the 3'-untranslated regions of RAB22A mRNA. Moreover, RAB22A overexpression significantly abolished the anti-tumor effects of miR-520b in a NOZ cell model. Western blot, qPCR and IHC analysis proved that human GBC tissues showed a higher RAB22A expression level than neighboring normal tissues. Additionally, there was a negative association between miR-520b and RAB22A expression.

CONCLUSIONS

MiR-520b had suppressive effects on GBC via targeting RAB22A in vitro.

[Cross-sectional study of family drug stockpile and children medication in China]

OBJECTIVE

To investigate the current situation of family medicine stockpile and children medication in China, analyze the existing problems and provide the rationalized suggestions.

METHODS

The questionnaire was designed and convenient sampling survey was performed in 20 children hospitals in China. Descriptive analysis was conducted on the survey results.

RESULTS

A total of 13 940 completed questionnaires were returned, 98.33% of the families had medicine stockpile, the top three types of the medicine for children were cold medicine(73.95%), oral paregoric/febrifuge(48.01%)and external used drugs for skin disease(wound)(41.10%). The medicine was bought according to physician's prescription and guide(71.18%). Drug poisoning occurred in children of 238 families(1.71%), overdose use was the first cause(44.96%). 22.33% of the parents didn't read the specification carefully before medicine use. The non-appropriate medication for children were mainly the use of adult medicine(32.70%), untimely medication(30.90%), non-rational or unneeded use of febrifuge(26.35%).

CONCLUSIONS

In China, the families mainly store common medicine for their children. The parents bought medicine mainly according to physician' s prescription and paid attention to the safety and efficiency of the medicine, but non-appropriate use of medicine was still common. It is necessary to improve the rational use of medicine for children through expert counsel and guidance.

Repetitive transcranial magnetic stimulation enhances spatial learning and synaptic plasticity via the VEGF and BDNF-NMDAR pathways in a rat model of vascular dementia

This study aimed to evaluate the effects of repetitive transcranial magnetic stimulation (rTMS) on learning and memory in a rat model of vascular dementia (VaD) and to analyze the associated mechanisms. Bilateral carotid artery occlusion (2-VO) was used to establish a rat model of VaD. High-frequency (5Hz) rTMS was performed on rats for four weeks. Spatial learning and memory abilities were evaluated using the Morris water maze (MWM), and synaptic plasticity in the hippocampus was assessed via long-term potentiation (LTP). Hippocampal expression of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF) and three subunits of the N-methyl-D-aspartic acid receptor (NMDAR), NR1, NR2A and NR2B, was analyzed by Western blotting. Compared with the VaD group, escape latency was decreased (P<0.05) and the time spent in the target quadrant and the percentage of swimming distance within that quadrant were increased (P<0.05) in the rTMS group. LTP at hippocampal CA3-CA1 synapses was enhanced by rTMS (P<0.05). VEGF expression was up-regulated following 2-VO and was further increased by rTMS (P<0.05). BDNF, NR1 and NR2B expression was decreased in the VaD group and increased by rTMS (P<0.05). There were no significant differences in NR2A expression among the three groups. These results suggest that rTMS improved learning and memory in the VaD model rats via the up-regulation of VEGF, BDNF and NMDARs. In addition, NR2B may be more important than NR2A for LTP induction in the hippocampus during rTMS treatment of VaD.

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.

Mussel-inspired nanofibrous sheet for suture-less stomach incision surgery

We report a dopamine-based crosslinker-conjugated gelatin/polycaprolactone nanofibrous sheet. The nanosheet was then employed to treat stomach incisions without sutures during surgery.

Radiological and clinical characterization of the lysosomal storage disorders: non-lipid disorders

Lysosomal storage diseases (LSDs) are a large group of genetic metabolic disorders that result in the accumulation of abnormal material, such as mucopolysaccharides, glycoproteins, amino acids and lipids, within cells. Since many LSDs manifest during infancy or early childhood, with potentially devastating consequences if left untreated, timely identification is imperative to prevent irreversible damage and early death. In this review, the key imaging features of the non-lipid or extralipid LSDs are examined and correlated with salient clinical manifestations and genetic information. Disorders are stratified based on the type of excess material causing tissue or organ dysfunction, with descriptions of the mucopolysaccharidoses, mucolipidoses, alpha-mannosidosis, glycogen storage disorder II and cystinosis. In addition, similarities and differences in radiological findings between each of these LSDs are highlighted to facilitate further recognition. Given the rare and extensive nature of the LSDs, mastery of their multiple clinical and radiological traits may seem challenging. However, an understanding of the distinguishing imaging characteristics of LSDs and their clinical correlates may allow radiologists to play a key role in the early diagnosis of these progressive and potentially fatal disorders.

A simplified paraffin embedding method for small botanical samples

We present a simplified paraffin embedding method suitable for unsuberized or unlignified small botanical samples (diameter < 0.3 cm). Only 2 h are required to yield plant tissues embedded in paraffin for anatomical observation and molecular analysis. Our method achieved morphological preservation of cell structures and conservation of nucleic acids that were equivalent to the traditional protocol. Fourier transform infrared spectrometry showed that the degree of degradation of the cytoplasmic components (e.g., protein) resulting from our simplified protocol was similar to that of the traditional protocol. The DNA samples embedded using the simplified method was extractable and could be used for PCR analysis. The DNA quality was equivalent to that embedded using the traditional method.

Localization of Per a 3 allergen in the gut and faecal pellets of the American cockroach (Periplaneta americana)

Cockroach-derived materials are known to be a major source of potent aeroallergens, causing allergic respiratory diseases such as asthma and allergic rhinitis. The aim of this study was to determine the localization of the major allergen, Per a 3 (Cr-PI), within the American cockroach (Periplaneta americana), which might reveal the relative importance of excreted materials and nonexcreted cockroach components as allergen sources. American cockroaches (P. americana) and their faecal pellets were embedded in paraffin, and serial sections were cut and collected on glass slides. After being stained with mouse polyclonal antiserum against Per a 3, the sections were incubated sequentially with biotin-labelled sheep antimouse immunoglobulin G (IgG) and a preformed fluorescent isothiocyanate (FITC)-avidin complex. Finally, the sections were mounted and examined under a fluorescent microscope. Examination of Per a 3 immunoreactivity on the sections of the American cockroaches (P. americana) revealed that the midgut mucosa, gut contents and faecal pellets were all strongly labelled. Per a 3 immunoreactive products were not detected in any other internal organs of the American cockroaches. These results suggest that Per a 3 allergen might be synthesized in and secreted from the epithelia of the midgut mucosa and excreted from the body in the faecal pellets.

Quantitative assessment of promoter methylation profiles in thyroid neoplasms

CONTEXT

Cancer-specific molecular markers are needed to supplement the cytopathological assessment of thyroid tumors, because a majority of patients with cytologically indeterminate nodules currently undergo thyroidectomy without a definitive diagnosis.

OBJECTIVE

The aim of this study was the quantitative assessment of promoter hypermethylation and its relation to the BRAF mutation in thyroid tumors.

DESIGN

Quantitative hypermethylation of Rassf1A, TSHR, RAR-beta2, DAPK, S100, p16, CDH1, CALCA, TIMP3, TGF-beta, and GSTpi was tested on a cohort of 82 benign and malignant thyroid tumors and five thyroid cancer cell lines.

SETTING

The study was conducted at a tertiary research hospital.

PATIENTS

Patients underwent surgical resection for a thyroid tumor from 2000 to 2003 at our institution.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURE

Final surgical pathology diagnosis was the main outcome measure.

RESULTS

Thyroid tumors showed hypermethylation for the following markers: Rassf1A, TSHR, RAR-beta2, DAPK, CDH1, TIMP3, and TGF-beta. A trend toward multiple hypermethylation was evident in cancer tissues, with hypermethylation of two or more markers detectable in 25% of hyperplasias, 38% of adenomas, 48% of thyroid cancers, and 100% of cell lines. A rank correlation analysis of marker hypermethylation suggests that a subset of these markers is epigenetically modified in concert, which may reflect an organ-specific regulation process. Furthermore, a positive correlation was found between the BRAF mutation and RAR-beta2, and a negative correlation was found between the BRAF mutation and Rassf1A.

CONCLUSIONS

Methylation-induced gene silencing appears to affect multiple genes in thyroid tissue and increases with cancer progression. Additional markers with better discriminatory power between benign and malignant samples are needed for the diagnostic assessment of cytologically indeterminate thyroid nodules.

BRAF mutation in thyroid cancer

Genetic alteration is the driving force for thyroid tumorigenesis and progression, based upon which novel approaches to the management of thyroid cancer can be developed. A recent important genetic finding in thyroid cancer is the oncogenic T1799A transversion mutation of BRAF (the gene for the B-type Raf kinase, BRAF). Since the initial report of this mutation in thyroid cancer 2 years ago, rapid advancements have been made. BRAF mutation is the most common genetic alteration in thyroid cancer, occurring in about 45% of sporadic papillary thyroid cancers (PTCs), particularly in the relatively aggressive subtypes, such as the tall-cell PTC. This mutation is mutually exclusive with other common genetic alterations, supporting its independent oncogenic role, as demonstrated by transgenic mouse studies that showed BRAF mutation-initiated development of PTC and its transition to anaplastic thyroid cancer. BRAF mutation is mutually exclusive with RET/PTC rearrangement, and also displays a reciprocal age association with this common genetic alteration in thyroid cancer. The T1799A BRAF mutation occurs exclusively in PTC and PTC-derived anaplastic thyroid cancer and is a specific diagnostic marker for this cancer when identified in cytological and histological specimens. This mutation is associated with a poorer clinicopathological outcome and is a novel independent molecular prognostic marker in the risk evaluation of thyroid cancer. Moreover, preclinical and clinical evaluations of the therapeutic value of novel specific mitogen-activated protein kinase pathway inhibitors in thyroid cancer are anticipated. This newly discovered BRAF mutation may prove to have an important impact on thyroid cancer in the clinic.

BRAF T1796A transversion mutation in various thyroid neoplasms

A high prevalence of activating mutation of the B type Raf kinase (BRAF) gene was recently reported in papillary thyroid cancer (PTC). However, the frequency of this mutation in several other types of thyroid neoplasms was not thoroughly investigated. In the present study, in addition to PTC, we evaluated various thyroid tumor types for the most common BRAF T1796A mutation by direct genomic DNA sequencing. We found a high and similar frequency (45%) of the BRAF T1796A mutation in two geographically distinct PTC patient populations: one composed of sporadic cases from North America, and the other from Kiev, Ukraine, that included individuals who were exposed to the Chernobyl nuclear accident. In contrast, we found BRAF mutation in only 20% of anaplastic thyroid cancers and no mutation in medullary thyroid cancers and benign thyroid hyperplasia. We also confirmed previous reports that the BRAF T1796A mutation did not occur in benign thyroid adenomas and follicular thyroid cancers. Specific analysis of the Ukraine patients with confirmed history of radiation exposure failed to show a higher incidence of BRAF mutation. Our results suggest that frequent occurrence of BRAF mutation is inherently associated with PTC, irrespective of geographic origin, and is apparently not a radiation-susceptible mutation. The lack or low prevalence of BRAF mutation in other thyroid neoplasms is consistent with the notion that other previously defined genetic alterations on the same signaling pathway are sufficient to cause tumorigenesis in most thyroid neoplasms.

[Somatic embryogenesis and plant regeneration in vitro from young shoots of Aralia elate (Miq.) Seem]

Explants excised from the young shoots of Aralia elata (Miq.) Seem. were cultured on MS media. Calli were induced from the explants on MS medium supplemented with 0.5 mg/L 2, 4-D, 0.5 mg/L BA and 0.5 mg/L NAA. Then these calli were transferred onto the MS medium containing 2.0 mg/L 2,4-D + 0.5 mg/L BA + 0.5 mg/L NAA and 0.2% activated charcoal. Under these conditions the somatic embryoids were observed and regenerated plants were obtained from somatic embryogenesis. Then, a experimental system with stability and high regenerating efficiency has been set up for the propagation of the young plants, the cell breeding technology and the control of somatic embryogenesis of Aralia elata (Miq.).

Species- and agonist-dependent differences in the deactivation-kinetics of P2X7 receptors

In this study we have expressed recombinant P2X7 receptors in HEK293 cells and examined the reasons for the species- and agonist-dependent differences in the time taken for the closure of the P2X7 receptor ion-channels after agonist removal. Channel closure times, measured in electrophysiological studies or by measuring cellular permeability to ethidium cations, were slower at rat than at human or mouse P2X7 channels following washout of the P2X7 agonist 2'- and 3'-O-(4-benzoylbenzoyl)-ATP (BzATP). In contrast, there were no species differences in channel closure times when ATP was the agonist. BzATP was more potent than ATP at the three species homologues and exhibited highest potency for rat P2X7 receptors suggesting that channel closure time was related to agonist potency. Furthermore, BzATP potency for the P2X7 receptor could be modified by changing extracellular ionic concentrations or by mutating the receptor and modifications which increased agonist potency also increased the time taken for channel closure. The dependence of channel closure time on agonist potency suggests it reflects agonist dissociation from the P2X7 receptor rather being an intrinsic property of the ion-channel. Consistent with this, our previous studies have shown that agonist potency increases after repeated agonist applications and in this study channel closure time at rat P2X7 receptors increased after repeated agonist applications. Overall these results suggest that the species differences in channel closure times reflect differences in agonist dissociation rates which arise as a consequence of the marked species differences in agonist potency.

[Actin is located in the nucleus and nuclear matrix of HeLa cells]

HeLa cell nuclei were isolated and the nuclear matrix specimens were prepared. After labelled with an anti-actin antibody and FITC-conjugated secondary antibody, both the nuclei and nuclear matrix specimens were observed to emanate specific yellow-green fluorescence. The fluorescent signals in the nuclear matrix were much stronger than that in the nuclei, and the signals in former were widespread throughout the whole structure while that in the latter were mainly defined to their peripheral regions. A 43 kD band was revealed in nuclei and nuclear matrix specimens by SDS-PAGE, and was then proved to be actin by Western blot, confirming the immuno-fluorescence observations. When stained with TRICT-conjugated phalloidin, both the nuclei and nuclear matrix specimens were found to give off specific, red fluorescent signals which represent the location of F-actin (filamentous actin), and the pattern of TRITC signals distribution in the nuclei and nuclear matrix showed similarity with that of FITC signals. The existence and significance of actin and F-actin in the nuclei and nuclear matrix were discussed.