Gerhardtia tomentosa and Ossicaulis borealis (Agaricales, Lyophyllaceae)—Two new species from northeast China

Background

Gerhardtia and Ossicaulis are two genera within the family Lyophyllaceae, which show an apparently poor species diversity worldwide. During the field investigation on wild macrofungi, six interesting collections within Gerhardtia and Ossicaulis genera are discovered in the northeastern China.

Methods

To identify whether these collections of Gerhardtia and Ossicaulis are novel species, we performed phylogenetic analyzes using the following DNA regions: the internal transcribed spacer (ITS) region and the large subunit nuclear ribosomal RNA (nrLSU) region. Moreover, a traditional morphological method also be conducted based on both the macro-morphological and micro-morphological features.

Results

The results indicated that these collections tested formed two independent lineages in each genus with a high support. In addition, they can easily be separated from all other taxa of the two genera in morphology. Based on the combination of morphological and molecular data, Gerhardtia tomentosa and Ossicaulis borealis, are confirmed as two new species to science.

Discussions

This study provided a theoretical basis is for the two lyophylloid genera and indicated that the biodiversity resources of northeastern China might be underestimated.

Corrigendum: Detection and homology analysis of carbapenem resistant Acinetobacter baumannii resistance gene

[This corrects the article DOI: 10.3389/fcimb.2022.987260.].

Continuous positive airway pressure for treating hypoxemia due to pulmonary vein injury: A case report

BACKGROUND

Vascular injury during thoracoscopic surgery for esophageal cancer is a rare but life-threatening complication that can lead to severe hypotension and hypoxemia. Anesthesiologists need to provide rapid and effective treatment to save patients' lives.

CASE SUMMARY

A 54-year-old male patient was scheduled to undergo a thoracoscopic-assisted radical resection of esophageal cancer through the upper abdomen and right chest. While dissociating the esophagus from the carina through the right chest, unexpected profuse bleeding occurred from a suspected pulmonary vascular hemorrhage. While the surgeon attempted to achieve hemostasis, the patient developed severe hypoxemia. The anesthesiologist implemented continuous positive airway pressure (CPAP) using a bronchial blocker (BB), which effectively improved the patient’s oxygenation and the operation was completed successfully.

CONCLUSION

CPAP using a BB can resolve severe hypoxemia caused by accidental injury of the left inferior pulmonary vein during surgery.

Detection and homology analysis of carbapenem resistant Acinetobacter baumannii resistance gene

Objective

To explore the carrying status and homology of carbapenem resistant Acinetobacter baumannii (CRAB) in our hospital.

Methods

From January 2015 to December 2017, 52 strains of acinetobacter baumannii isolated from the bacteria room of the clinical laboratory of Baogang hospital in Inner Mongolia were selected as the research object. K-B disk diffusion method and Vitek-2 were used to determine the drug sensitivity of Acinetobacter baumannii. The drug resistance gene was detected by polymerase chain reaction (PCR) and its homology was analyzed by pulsed field gel electrophoresis (PFGE).

Results

Except for Cefoperazone/sulbactam, other antibiotics were resistant to ab. The detection rate of drug resistance gene class C β-lactamases (ADC) was 100%, and the higher detection rates of other drug resistance genes were class D β-lactamases (OXA)-51 (36 strains, 90.0%),disinfectant gene qacE△1-sull (32 strains, 80.0%), and klebsiella pneumoniae carbapenemase (KPC) gene was not detected. 2-8 drug resistance genes were detected in each CRAB strain, and the strains with 6 drug resistance genes were the most (15 strains, 37.5%); Among the detected drug-resistant gene combinations, ADC+OXA-23 + OXA-51 gene was detected at the same time (29 strains, 72.5%), followed by ADC+ intl1 + qacE △ 1-sull gene (26 strains, 65.0%), ADC + qacE △ 1-sull + ant (3 '') -i gene (19 strains, 47.5%), and 11 strains (27.5%). There were 19 different types in PFGE homology test, each type was 1-9 strains, including 9 strains of A5 type and 8 strains of A18 type, mainly from intensive care unit.

Conclusion

CRAB in the hospital is highly resistant to common clinical antibiotics. OXA-23 and OXA-51 genes are most likely to be the main factors causing drug resistance of Acinetobacter baumannii in the hospital. Homology analysis showed that there was CRAB nosocomial infection transmission in different wards of the hospital.

Melanoleuca subgriseoflava and M. substridula-two new Melanoleuca species (Agaricales, Basidiomycota) described from China

Two new Melanoleuca species, Melanoleuca subgriseoflava and M. substridula, are originally reported and described in China based on both morphological and molecular methods. Melanoleuca subgriseoflava, collected in Liaoning province, is mainly characterized by its greyish-brown to yellowish-grey pileus, creamy to light orange lamellae, greyish-yellow context, round and warted basidiospores and fusiform hymenial cystidia. Melanoleuca substridula, discovered in Sichuan province, is mainly characterized by its light brown to dark brown pileus, whitish lamellae, light brown to greyish-brown stipe, round and warted basidiospores and lack of any forms of cystidia. The phylogenetic relationships as well as divergence-time estimation were analyzed using the combined data set (ITS-nrLSU-RPB2), and the results showed that the two Melanoleuca species formed two distinct lineages. Based on the combination of morphological and molecular data, M. subgriseoflava and M. substridula are confirmed as two new species to science. A theoretical basis is provided for the species diversity of Melanoleuca.

Exosome-mediated transfer of MIF confers temozolomide resistance by regulating TIMP3/PI3K/AKT axis in gliomas

Temozolomide (TMZ) resistance is an important cause of clinical treatment failure and poor prognosis in gliomas. Increasing evidence indicates that cancer-derived exosomes contribute to chemoresistance; however, the specific contribution of glioma-derived exosomes remains unclear. The aim of this study was to explore the role and underlying mechanisms of exosomal macrophage migration inhibitory factor (MIF) on TMZ resistance in gliomas. We first demonstrated that MIF was upregulated in the exosomes of TMZ-resistant cells, engendering the transfer of TMZ resistance to sensitive cells. Our results indicated that exosomal MIF conferred TMZ resistance to sensitive cells through the enhancement of cell proliferation and the repression of cell apoptosis upon TMZ exposure. MIF knockdown enhanced TMZ sensitivity in resistant glioma cells by upregulating Metalloproteinase Inhibitor 3 (TIMP3) and subsequently suppressing the PI3K/AKT signaling pathway. Additionally, exosomal MIF promoted tumor growth and TMZ resistance of glioma cells in vivo, while IOS-1 (MIF inhibitor) promotes glioma TMZ sensitive in vivo. Taken together, our study demonstrated that exosome-mediated transfer of MIF enhanced TMZ resistance in glioma through downregulating TIMP3 and further activating the PI3K/AKT signaling pathway, highlighting a prognostic biomarker and promising therapeutic target for TMZ treatment in gliomas.

Three new Melanoleuca species (Agaricales, Basidiomycota) from north-eastern China, supported by morphological and molecular data

Three new Melanoleuca species, M.chifengense, M.griseoflava and M.pallidorosea, were discovered in the northeast of China. Melanoleucachifengense is morphologically characterised by its grey to yellowish-grey pileus, decurrent lamellae, grey to yellowish-brown stipe, yellowish-grey context, ellipsoid basidiospores with irregular warts and lack of hymenial cystidia. Melanoleucagriseoflava is mainly characterised by its greyish-brown pileus, adnexed to adnate lamellae, greyish-yellow context, fusiform cystidia and almost reticulate basidiospores. Melanoleucapallidorosea is characterised by its pinkish-white pileus, white and decurrent lamellae, ellipsoid basidiospores with round and scattered warts and lack of hymenial cystidia. The phylogenetic relationship of the three species was determined by the analyses of the ITS region and the combined data matrix (ITS-nrLSU-RPB2), respectively. The results showed that the three species formed three independent lineages. Based on the combination of both morphological and molecular data, M.chifengense, M.griseoflava and M.pallidorosea were confirmed to be new species. The morphological similarities of the three new species is also discussed.

Microstructure Dependence of Effective Thermal Conductivity of EB-PVD TBCs

Microstructure dependence of effective thermal conductivity of the coating was investigated to optimize the thermal insulation of columnar structure electron beam physical vapor deposition (EB-PVD coating), considering constraints by mechanical stress. First, a three-dimensional finite element model of multiple columnar structure was established to involve thermal contact resistance across the interfaces between the adjacent columnar structures. Then, the mathematical formula of each structural parameter was derived to demonstrate the numerical outcome and predict the effective thermal conductivity. After that, the heat conduction characteristics of the columnar structured coating was analyzed to reveal the dependence of the effective thermal conductivity of the thermal barrier coatings (TBCs) on its microstructure characteristics, including the column diameter, the thickness of coating, the ratio of the height of fine column to coarse column and the inclination angle of columns. Finally, the influence of each microstructural parameter on the mechanical stress of the TBCs was studied by a mathematic model, and the optimization of the inclination angle was proposed, considering the thermal insulation and mechanical stress of the coating.

[Screening and verification of proteins of Salvia miltiorrhiza polyphenol oxidase interaction]

Polyphenol oxidase(PPO) is an important antioxidant enzyme in plants. It has the functions of scavenging active oxygen and synthesizing phenols, lignin, and plant protection factors, and can enhance the plant's resistance to stress and resistance to pests and diseases. Our previous research found that Salvia miltiorrhiza PPO gene can positively regulate salvianolic acid B synthesis. In order to further explore the mechanism, a pGBKT7-PPO bait vector was constructed using the cloned S. miltiorrhiza polyphenol oxidase gene(SmPPO, GenBank accession number: KF712274.1), and verified that it had no self-activation and no toxicity. The titer of S. miltiorrhiza cDNA library constructed by our laboratory was 4.75 × 107 cfu·mL~(-1), which met the requirements for library construction. Through yeast two-hybrid test, 22 proteins that could interact with SmPPO were screened. Only yeast PAL1 and TAT interacted with SmPPO through yeast co-transformation verification. Further verification was performed by bimolecular fluorescence complementary detection(BiFC). Only TAT and SmPPO interacted, so it meant that TAT and SmPPO interacted. TAT and SmPPO were truncated according to the domain, respectively. The first 126 amino acids of SmPPO and tyrosine amino transferase(TAT) were obtained to interact on the cell membrane and chloroplast. SmPPO was obtained by subcellular localization test, which was mainly loca-lized on the nucleus and cell membrane; TAT was localized on the cell membrane. Real-time quantitative PCR results showed that the SmPPO gene was mainly expressed in roots and stems; the TAT gene was expressed in roots, and the expression level in stems and flowers was low. This article lays a solid foundation for the in-depth study of the molecular mechanism of the interaction of S. miltiorrhiza SmPPO and TAT to regulate the synthesis of phenolic substances.

Capacitance-Voltage Characteristics Analysis of Indium Zinc Oxide Thin Film Transistors Based Ultraviolet Light Irradiation

The mechanism of solution-processed indium zinc oxide (IZO) thin film transistors (TFTs) made by simultaneous spin coating and ultraviolet (UV) light irradiation was investigated by capacitance-voltage (C-V) measurement. The application of UV light on the IZO TFTs was found to improve the thin film surface structure, and pledge to receive low degree of roughness. Meanwhile, electrical characteristics indicated that the TFT prepared at the UV light irradiation with 90 s exhibits the best performance with field-effect mobility 5.6 cm²/Vs, threshold voltage ═ -0.13 V, subthreshold gate swing 0.64 V/decade and on/off ratio ═ 1.7 × 10⁶. In the C-V contrastive analysis with different UV light irradiation time by 60 s and 90 s, the frequency was varied from 100 Hz to 10 kHz to investigate low as well as high frequency C-V.

Indium Zinc Oxide Thin-Film Transistors with Ultraviolet Post-Annealing Treatment

Ultraviolet treatment (UV) light was performed for indium zinc oxide thin-film transistors (TFTs) for different time so as to study the effects of post-annealing on electrical characteristic of TFTs. Electrical characteristic results proved that the value of high mobility after UV post-annealing process (2 mW/cm². for 30 s was obviously enhanced, and it had an acceptable on/off ratio, reasonable threshold voltage, and subthreshold swing. Among them, the value of the electronic mobility is 2.41 cm²/Vs, the threshold voltage value is 8.31 V, the on/off current ratio value is 2×2 × 10⁵, and the subthreshold swing value is 1.13 V/dec.

[Numerical simulation study of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction]

Objective: To construct computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction, and evaluate the application of computational fluid model on aortic remodeling of type B aortic dissection. Methods: Consecutive computed tomographic angiograph data was acquired from a patient with type B aortic dissection at initial diagnosis, 1 week and 6 years after endovascular repair of primary tear entry and 3 months after endovascular repair of distal tear erosion. Three-dimensional model of aortic dissection was reversely reconstructed by Mimics, and then the model was smoothened by Geomagic. Computational fluid dynamic numerical simulation was performed in ANSYS by the means of two-way fluid-structure interaction, and the relation between blood dynamic characteristic and thrombosed remodeling of type B aortic dissection was evaluated. Results: The computational fluid model of type B aortic dissection using patient-specific reverse engineering and fluid-structure interaction method was successfully constructed. Local peak of blood pressure on the convex surface of junction at aortic arch and descending aorta was found. The wall stress was much higher at the false lumen than that at the true lumen, and the peak of wall stress converged on the edge and tear entry of false lumen. After the exclusion of proximal tear entry, the blood streamline was decreased significantly and flowed reversely. Blood flow in the remaining false lumen was retrograded from the entry at left iliac artery and formed turbulence at the top of false lumen, which was benefit for dissection thrombus remodeling. The higher pressure at the false lumen was associated with the new formation of aortic aneurysm at the distal tear. Conclusion: The computational fluid model of aortic dissection based on patient-specific reverse engineering and fluid-structure interaction method can successfully reveal the relatively truly blood dynamic and wall pressure characteristic of type B aortic dissection.

Genetic diversity of Lepista nuda (Agaricales, Basidiomycota) in Northeast China as indicated by SRAP and ISSR markers

Lepista nuda is a popular wild edible mushroom that grows in China. In this study, we used ISSR and SRAP molecular markers to analyze the genetic diversity of 72 samples of L. nuda from eight populations in Northeast China. In total, six ISSR primers and five pairs of SRAP primers that produced clear and polymorphic banding profiles were selected for assessing L. nuda genetic diversity. The results revealed a high level of genetic variation among the 72 samples (94.4% polymorphism) but a low degree of gene flow among the populations. Among L. nuda populations, genetic distance was not correlated significantly with geographic distance. The antioxidant activity of the samples from each population was also tested and the result showed that all the selected samples had more than 60% DPPH scavenging activities. Nonetheless, the antioxidant activity diversity is not coincident with both the genetic diversity and the geographic distribution. The results indicate that ISSR and SRAP molecular markers are useful for studying the genetic diversity of L. nuda. The results also suggest that L. nuda populations in Northeast China require protection.

Carrier-free, self-assembled pure drug nanorods composed of 10-hydroxycamptothecin and chlorin e6 for combinatorial chemo-photodynamic antitumor therapy in vivo

Carrier-free nanodrugs formulated from the supramolecular self-assembly of pure drug molecules have emerged as an innovative and promising strategy for tumor therapy. We report herein a new and simple method to directly assemble a small hydrophobic anticancer drug, 10-hydroxycamptothecin (HCPT), with a photosensitizer chlorin e6 (Ce6) to form stable, discrete nanorods (NRs), which not only circumvent the extreme hydrophobicity of HCPT but also incorporate two different modalities into one delivery system for combination therapy. Different ratios of HCPT to Ce6 were evaluated to afford the optimal nanoformulation. The as-prepared HCPT/Ce6 NRs were fully characterized, indicating a relatively uniform size of about 360 nm in length and 135 nm in width, and a surface charge of about -33 mV. Efficient internalization of the NRs by cancer cells was observed by using a confocal microscope and the generation of singlet oxygen species arising from the NRs under 655 nm laser irradiation was detected by DCFH-DA. As a result, very potent in vitro efficacy against several kinds of cancer cell lines was achieved through chemo-photodynamic dual therapy. The in vivo tumor suppression effect of HCPT/Ce6 NRs was verified on a subcutaneous xenograft mouse model, achieving almost complete inhibition of the tumor growth, which may benefit from the superiority of nanomedicine and combination therapy. The rationale of this facile and green strategy for carrier-free nanodrug formulation via the self-assembly approach might provide new opportunities for the development of combinatorial therapeutics for tumors.

Pinning effect of reactive elements on adhesion energy and adhesive strength of incoherent Al2O3/NiAl interface

The profound effects of reactive elements (REs) on the adhesion energy and adhesive strength of the α-Al2O3/β-NiAl interface in thermal barrier coating (TBC) systems have attracted increasing attention because RE-doping has played a significant role in improving the thermal cycling lifetime of TBCs. However, the fundamental mechanism is, so far, not well understood due to the experimental difficulty and theoretical complexity in interface modelling. For this purpose, in the present study we have performed comprehensive density functional theory calculations and information targeted experiments to underline the origin of the surprising enhancement of interface adhesion, stability and mechanical strength of the α-Al2O3/β-NiAl interface by different RE doping levels. Our results suggest that the interface failure firstly appears within the NiAl layer adjacent to the Al-terminated oxide under mechanical loading, while the formation of O-RE-Ni bond pairs at the interface can effectively hinder the interface de-cohesion, providing a higher mechanical strength. By comparing several typical REs, it is observed that Hf can emerge not only with the highest interface adhesion energy, but also the highest mechanical strength; in agreement with our experimental results. By continuously increasing the dopant concentration, the strengthening effect may increase correspondingly, but is limited by the solute solubility. These results shed light into the effect of REs on the stability and strength of the α-Al2O3/β-NiAl interface, providing theoretical guidance for interface design via a combinational analysis of bond topology and electronic structure.

Epidermal growth factor receptor tyrosine kinase inhibitors with conventional chemotherapy for the treatment of non-small cell lung cancer

We report a Chinese male patient with advanced stage lung squamous cell carcinoma who developed brain metastases after responding to treatment comprising six cycles of conventional chemotherapy with docetaxel and cisplatin. The patient was then treated with oral erlotinib (150 mg/day) and whole-brain radiation therapy followed by four cycles of docetaxel and carboplatin chemotherapy. The patient then received gefitinib (250 mg/day) as a maintenance therapy until the end of the follow-up period. In this patient, progression-free survival, defined as the interval from the initiation of first-line chemotherapy to the cessation of erlotinib due to progressive disease or death from any cause, was 3 months. Overall survival, defined as the interval from the initiation of first-line chemotherapy to death from any cause, was 75 months. Erlotinib was well tolerated in combination with whole-brain radiation therapy and a favorable objective response rate was observed. Furthermore, targeted drug treatment warrants consideration in patients with a negative epidermal growth factor receptor mutation status and male patients with a history of smoking.

[Association factors analysis of diarrhea in patients receiving kidney transplantation]

OBJECTIVE

To investigate the factors in association with colorectal disorders in adult renal transplant recipients.

METHODS

A retrospective cohort study was carried out with clinical, microbiological and management data regarding diarrhea in 513 renal transplant recipients from Jan. 2007 to Dec. 2012.

RESULTS

Of the 513 patients, 118(23.00%) with no history of ulcerative colitis, were found to have diarrhea after kidney transplantation. In the 118 patients, diarrhea was probably caused by administration of immunosuppressive agents in 65 cases (55.08%), in 30 cases (25.42%) diarrhea was antibiotics associated, and in 23 cases (19.49%) it was due to infections, including bacterial, fungal and viral infections. Diarrhea occurred soon after transplantation in most cases. Of the 118 patients, the symptom of diarrhea occurred in the first 1 month in 84 cases (71.19%), and in the next 5 months in 16 cases (13.56%), and the other 18 cases (15.05%) occurred after 180 days after transplantation. Of the 118 patients, 84 cases (71.19%) were relieved or cured after proper diets, the symptomatic therapy or the adjust meat of the doses of immunosuppressive agents: 18 cases (15.25%) needed to use or adjust the antibiotics , 16 cases (13.56%) had to stop mycophenolate mofetil and convert to other drugs.

CONCLUSION

Immunosuppressive agents, antibiotics and infection are the common causes of diarrhea after kidney transplantation. The outcome is good with appropriate conservative management.

Efficient isolation of high-quality RNA from lotus Nelumbo nucifera ssp nucifera tissues

Nelumbo nucifera is widely used as food, as an ornamental, in medicine, and as packing material; it is also reported to have anti-HIV effects and antioxidant capacity. We sought an improved method for extracting high-quality total RNA from different tissues of N. nucifera. Four methods for RNA extraction were assessed for their ability to recover high-quality RNA applicable for evaluation of polyphenol oxidase (PPO) gene expression profiles. The recovery and quality of the RNA obtained from five different tissues by the best CTAB-LiCl method were evaluated through UV light absorbance. Both A(260)/A(280) and A(260)/A(230) absorbance ratios were more than 2.0; the yield ranged from 59.87 to 163.75 μg/g fresh weight. The brightness of the 28S band was approximately twice that of 18S; the latter was also considered as high-quality RNA. The PPO gene fragment (606 bp) was successfully amplified by RT-PCR, demonstrating the integrity of the isolated RNA. The relative expression levels of the PPO gene based on RT-PCR in five tissues of lotus were: rhizome buds (2.66), young leaves (2.42), fresh cut rhizome (2.02), petals (1.80), and petiole (1.65), using housekeeping gene β-actin as an internal control. We concluded that the total RNA isolated by this protocol is of sufficient quality for molecular applications.

[Characteristics of human metapneumovirus respiratory tract infection in children and the relationship between the infection and meteorological conditions]

OBJECTIVE

To study the epidemiology of human metapneumovirus (hMPV) infection in children and its relations with meteorological conditions in Suzhou.

METHOD

Samples obtained from 6655 children hospitalized with acute respiratory tract infections (ARIs) during the period from 2006 to 2009, were tested for virus pathogens. Nasopharyngeal aspirates were obtained from the children according to a standard protocol and were tested for respiratory syncytial virus (RSV), influenza viruses (IFV) A and B, parainfluenza virus (PIV) types 1, 2, and 3 and adenovirus (ADV) with direct immunofluorescence assay. Samples were tested for hMPV with reverse transcription polymerase chain reaction (RT-PCR). Meteorological conditions including mean temperature, relative humidity, rainfall amount, sum of sunshine and mean wind velocity were collected monthly. The relationship between activity of the virus and meteorological conditions was analyzed by linear regression and stepwise regression analysis.

RESULT

Viral pathogens were identified in 32.2% of 6655 specimens. The positive rate of hMPV was 8.9%, RSV was 15.7%, IFV, PIV and ADV detection rates were less than that of hMPV. The annual positive rate of hMPV from 2006 to 2009 was 8.2%, 8.1%, 12.7%, 7.4% respectively (χ(2) = 33.23, P < 0.05). The hMPV positive rate of the four seasons was 11.6%, 7.6%, 4.7% and 11.7%, respectively, detection rate in winter and spring was significantly higher than those in summer and autumn (χ(2) = 74.67, P < 0.001). The positive rate of hMPV and the monthly mean temperature was moderately correlated (r = -0.43), and the monthly average rainfall (r = -0.29), monthly mean relative humidity (r = -0.27), monthly average sunshine duration (r = -0.11), the monthly average wind speed (r = -0.13) had low correlations.

CONCLUSION

hMPV was the second most common viral pathogen of acute respiratory tract infection in children in Suzhou, which prevailed predominantly in the winter and spring. Climatic factors, especially temperature and rainfall may affect the prevalence of hMPV.

Up-regulation of the transient A-type K+ current (IA) in the differentiation of neural stem cells of the early postnatal rat hippocampus

BACKGROUND

Neural stem cells (NSCs) not only are essential to cell replacement therapy and transplantation in clinical settings, but also provide a unique model for the research into neurogenesis and epigenesis. However, little attention has been paid to the electrophysiological characterization of NSC development. This work aimed to identify whether the morphological neuronal differentiation process in NSCs included changes in the electrophysiological properties of transient A-type K(+) currents (I(A)).

METHODS

NSCs were isolated from early postnatal rat hippocampus and were multiplied in basic serum-free medium containing basic fibroblast growth factor. Potassium currents were investigated and compared using whole-cell patch-clamp techniques and one-way analysis of variance (ANOVA), respectively.

RESULTS

Compared with NSC-derived neurons, cloned NSCs (cNSCs) had a more positive resting membrane potential, a higher input resistance, and a lower membrane capacitance. Part of cNSCs and NSC-derived neurons possessed both delayed-rectifier K(+) currents (I(DR)) and I(A), steady-state activation of I(A) in cNSCs (half-maximal activation at (21.34 +/- 4.37) mV) occurred at a more positive voltage than in NSC-derived neurons at 1-6 days in vitro (half-maximal activation at (12.85 +/- 4.19) mV).

CONCLUSIONS

Our research revealed a developmental up-regulation of the I(A) component during differentiation of postnatal NSCs. Together with the marked developmental up-regulation of I(DR) in vitro neuronal differentiation we have previously found, the voltage-gated potassium channels may participate in neuronal maturation process.

[Influence of the interruption of arteria iliaca interna distal end on penile vascularity and erectile function in male renal transplant recipients]

OBJECTIVE

It is controversial whether unilateral interruption of the arteria iliaca interna distal end affects penile hemodynamics and erectile function. The purpose of this study was to prospectively evaluate this influence by detecting the blood flow of the penile artery before and after renal transplantation.

METHODS

Thirty-three patients with chronic renal failure (CRF) on maintenance hemodialysis (MHD) received renal transplantation, the grafts revascularized by end-to-end anastomosis to the right internal iliac artery. Six months before and after the surgery, we obtained the IIEF scores of the patients, recorded their penile blood flow on color Doppler ultrasonography and the levels of serum creatinine, hemoglobin and serum cholesterol, and analyzed post-transplantation immunosuppressive medication.

RESULTS

The patients ranged in age from 21 to 55 years, of whom 36% had erectile dysfunction (ED) during MHD, and 33% after renal transplantation. A total of 67% of the renal transplant recipients (RTR) complained of unchanged and 15% deteriorated ED, while 18% admitted improved erectile function. The patients showed a significantly stronger sexual desire after the transplantation than before it (6.2 +/- 1.6 vs 8.9 +/- 0.9, P < 0.01). There was a significant decrease in peak systolic velocity (PSV) in the cavernous arteries after transplantation as compared with pre-transplantation (P < 0.01). Penile arterial blood flow insufficiency was found in none of the RTRs.

CONCLUSION

Unilateral interruption of the internal iliac artery decreases penile arterial blood flow, but not to such a degree as to result in ED. Unilateral interruption of the arteria iliaca interna distal end does not affect the erectile function of RTRs.

[Significance of dual-time-point 18F-FDG PET imaging in evaluation of hilar and mediastinal lymph node metastasis in non-small-cell lung cancer]

OBJECTIVE

To explore the diagnostic value of dual-time-point 18F-FDG PET-CT imaging in detecting hilar and mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC).

METHODS

Forty-six patients with NSCLC underwent standard whole body single-time 18F-FDG PET-CT scans and a delayed imaging for the thorax alone before surgery, meanwhile, the standard uptake value (SUV) and retention index (RI) were calculated.

RESULTS

A total number of 584 lymph nodes were excised in the 46 patients. Of these, 134 metastatic lymph nodes were pathologically confirmed in 31 patients. There were 189 lymph nodes detected and suspected to be metastatic by standard single-time 18 F-FDG PET-CT imaging, and 161 by dual-time-point imaging. Therefore, the sensitivity, specificity, diagnostic accuracy, positive predictive value and negative predictive value in the detection of hilar and mediastinal lymph node metastasis were 87.3%, 84.0%, 84.8%, 61.9% and 95.7% by standard single-time 18F-FDG PET-CT imaging, versus 94.8%, 92.2%, 92.8%, 78.9% and 98.1%, respectively, by dual-time-point imaging. There was a statistically significant difference in the detection of lymph node metastasis between the standard single-time imaging and dual-time-point 18F-FDG PET-CT imaging.

CONCLUSION

Dual-time-point 18F-FDG PET-CT imaging is more sensitive, specific and accurate than standard single-time 18F-FDG PET-CT imaging in the detection of hilar and mediastinal lymph node metastasis, and may provide more information for diagnosis, staging and treatment of non-small cell lung cancer.

[Electrophysiological properties of outward voltage-gated potassium channels of neural stem cells from adult rat hippocampus]

OBJECTIVE

To explore the electrophysiological properties of outward voltage-gated potassium channels of neural stem cells (NSCs) from adult rat hippocampus.

METHODS

NSCs were isolated from the hippocampus of adult SD rats with serum-free incubation and single-cell cloning technique. Immunochemistry technique was employed to identify the clone cells and clone cell-derived progeny. Electrophysiological recordings of various outward voltage-gated potassium channels were performed at room temperature using whole-cell patch clamp.

RESULTS

The floating neural spheres from the hippocampus showed the expression of nestin antigen, and were able to differentiate into neural cells expressing Yuj1 antigen and glial fibrillary acidic protein (GFAP) respectively in vitro. Three type specialized ion channels were find in cultured NSCs: The outward delayed rectifier outward K(+) currents (I(DR)) was characterized by a slow activation with depolarization and a sensitivity to tetraethylammonium (TEA). The current density of transient A type K(+) currents (I(A)) was 11 pA/pF +/- 3 pA/pF and 29 pA/pF +/- 7 pA/pF (n = 11) at +20 mV and +50 mV respectively, which was characterized by a rapid activation with depolarization and could be blocked by 4-AP. The large conductance calcium activated potassium (BKCa) channels was identified by the inhibition of iberiotoxin (IbTX). The current density of this channel at +80 mV was 56 pA/pF +/- 4 pA/pF and 45 pA/pF +/- 4 pA/pF (n = 6, P < 0.05) before and after application of 100 nM IbTX respectively.

CONCLUSION

The cultured NSCs of adult rat hippocampus express at least three kinds of outward voltage-gated potassium channels, I(DR), I(A), and BKCa in vitro.

[Preliminary study of 18F-FDG PET-CT in defining lymph node radiation target volume for non-small-cell lung cancer patients]

OBJECTIVE

To investigate the value of 18F-FDG PET-CT in detecting metastatic lymph node and radiation planning for patient with non-small-cell lung cancer (NSCLC).

METHODS

The data of 58 NSCLC patients were retrospectively analyzed. Preoperatively, Both 18F-FDG PET-CT and CT scan were performed for all patients. Blinded interpretation of these images was then carried out. The gross tumor volume defined by radiation oncologist based on imaging results of either PET-CT or CT alone was compared with pathological results eventually.

RESULTS

The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of detecting metastatic lymph node in the mediastinum was 56.0%, 54.2%, 54.8%, 38.9%, 70.3% by CT alone, and 88.0%, 85.4%, 86.3%, 75.9%, 93.2% by PET-CT, respectively. There was a statisticalty significant difference between two methods(P < 0.05). However, statisticalty no significant difference in detecting hilar lymph nodes was observed. The radiation target volume defined by CT was identical to that by PET-CT in 31(53.5%) cases, but changed in the other 27 (46.5%) cases when 18F-FDG PET data was added. The accuracy was 75.9% in detecting metastatic lymph nodes in the radiation target volume defined by PET-CT, while it was much lower by CT alone (48.3%) with a statistically significant difference between two methods (P < 0.05).

CONCLUSION

18F-FDG PET-CT is more accurate than CT alone in assessment of mediastinal lymph nodes for NSCLC patients. It may be recommended as a method in defining the radiation target volume.

Nonequilibrium Solid Phase Formation Studied by Lattice Dynamics Calculation and Ion Beam Mixing in an Immiscible Co−Ag System

For the equilibrium immiscible Co-Ag system, a proven realistic ab initio derived n-body potential is applied to study the nonequilibrium solid phase formation at three chemical stoichiometries of Co/Ag = 1:3, 1:1, and 3:1. To predict the structural stability, the elastic constants and the phonon spectra are calculated at the chosen stoichiometries with a total of eight hypothetical crystalline structures. The calculated results suggest that four compounds, that is, D0(3) CoAg3, B1 CoAg, B2 CoAg, and D0(3) Co3Ag, are unstable, as they all feature negative elastic constants as well as imaginary phonons, and that another four compounds of both fcc-type L1(2) and hcp-type D0(19) structures at chemical stoichiometries of Co/Ag = 1:3 and 3:1, respectively, may elastically be favored and therefore obtainable under some specific conditions. It is also found that all the calculated elastic constants and phonon spectra are coincident within the framework of the elastic theory. Moreover, the calculated elastic constants are in good agreement with those acquired directly from ab initio calculations, lending support to the validity of the ab initio derived n-body Co-Ag potential as well as its resultant elastic constants and the phonon spectra. Interestingly, some of the predicted nonequilibrium solid phases, that is, two hcp-type compounds at chemical stoichiometries of Co/Ag = 1:3 and 3:1, respectively, are indeed obtained in ion beam mixing experiments and their lattice constants determined by diffraction analysis are in good agreement with those from calculations.

N-acetylglucosaminyltransferase V modifies the signaling pathway of epidermal growth factor receptor

Transfection of sense cDNA of N-acetylglucosamyltransferase V (GnTV-S) into human H7721 hepatocarcinoma cells resulted in an increase in the N-acetylglucosaminebeta1,6mannosealpha1,3- branch (GnT-V product) on the N-glycans of epidermal growth factor (EGF) receptor (EGFR), and promotion of its EGF binding and tyrosine autophosphorylation, but showed little effect on the expression of EGFR protein. The phosphorylation at T308, S473 and tyrosine residue(s) and the activity of protein kinase B (Akt/PKB) as well as the phosphorylation of p42/44 mitogen-activated protein kinase (MAPK) and MAPK kinase (MEK) before and after EGF stimulation were concomitantly increased. Conversely, in the antisense GnT-V (GnTV-AS)-transfected H7721 cells, all the results were the reverse of those with GnTV-S-transfected cells. After the cells were treated with 1-deoxymannojirimycin, an inhibitor of N-glycan processing at high mannose, or antibody against the extracellular glycan domain of EGFR, the differences in PKB activity, p42/44 MAPK and MEK phosphorylation among GnTV-S-, GnTV-AS- and mock-transfected cells were significantly attenuated. These findings indicate that the altered expression of GnT-V will change the glycan structure and function of EGFR, which may modify downstream signal transduction.

Relationship between metastasis-associated phenotypes and N-glycan structure of surface glycoproteins in human hepatocarcinoma cells

PURPOSE

To study the relation of N-glycan structure on cell surface glycoproteins to the metastatic phenotypes.

METHODS

Two human hepatocarcinoma 7721 cell lines transfected with sense or antisense cDNA of GnT-V, named GnT-V/7721 and GnT-V-AS/7721, respectively, were adopted, because GnT-V can change the antennary number and the content of the beta 1,6 GlcNAc branch in N-glycans. The effects of over- and under-expression of GnT-V on the metastasis-associated phenotype of the transfected cells were investigated and compared with the cells mock-transfected with the plasmid vector.

RESULTS

In GnT-V/7721 cells, GnT-V activity was increased by 92% compared with the mock cells. HRP-labeled lectin staining of transfected cells showed elevated intensity with HRP-L-PHA and reduced intensity with HRP-ConA, suggesting the increased antennary number and content of the beta 1,6 GlcNAc branch in N-glycans. Analysis of the N-glycan structure of [3H]-labeled glycopeptides prepared from cell-surface [3H] glycoproteins using DSA-affinity chromatography also revealed the above change of the N-glycan structure in a more quantitative manner. GnT-V/7721 cells showed a suppressed cell attachment to fibronectin (Fn) or laminin (Ln), and increased cell migration and invasion through matrigel. In contrast, GnT-V-AS/7721 cells showed reduction of both GnT-V activity and content of the beta 1,6 branch in N-linked glycans, elevation of cell attachment to Fn or Ln, and decline of cell migration and invasion through matrigel. These changes were just the opposite to those in GnT-V/7721 cells.

CONCLUSIONS

The alteration of N-glycan structure in surface glycoproteins resulting from the activity change of GnT-V contributes to the alterations in metastasis-associated phenotypes. The product of GnT-V, the beta 1,6 GlcNAc branch in N-linked glycans, is a structural factor of adhesion inhibition and invasion promotion. GnT-V is, therefore, closely related to cancer metastasis and its over-expression is an important molecular mechanism of metastasis.

Down-regulation of N-acetylglucosaminyltransferase V by tumorigenesis- or metastasis-suppressor gene and its relation to metastatic potential of human hepatocarcinoma cells

The effects of transfection of the metastasis suppressor gene nm23-H1 and cell-cycle related tumor-suppressor gene p16 on the activity of N-acetylglucosaminyltransferase V (GnT-V) and their relations to cancer metastatic potential were investigated. After transfection of nm23-H1 into 7721 human hepatocarcinoma cells and A549 human lung cancer cells, the activities of GnT-V were decreased by 28%-42% in the cells. In contrast, when p16 was transfected into these two cell lines, the decrease of GnT-V activity was only observed in A549 cells. This was probably to be due to the obvious expression of p16 gene in parental 7721 cells and the deletion of p16 in A549 cells. The decrease of GnT-V mRNA was only observed in nm23-H1-transfected cells, but not in p16-transfected A549 cells, suggesting that these two genes regulated GnT-V via different mechanisms. Horseradish peroxidase (HRP)-lectin staining showed that the 7721 cells transfected with nm23-H1 or the A549 cells transfected with p16 displayed a decreased intensity with HRP-leucoagglutinating phytohemagglutinin and increased intensity with HRP-concanavalin A, indicating the decline of beta1,6 N-acetylglucosamine branching structure on the asparagine-linked glycans of cell-surface and intracellular glycoproteins. The nm23-H1 transfected 7721 cells also displayed some changes in metastasis-related phenotypes, including the increase in cell adhesion to fibronectin (Fn), the decline in cell adhesion to laminin (Ln), and the decreased cell migration and invasion through matrigel. Transfection of antisense GnT-V cDNA into 7721 cells resulted in a decrease of GnT-V activity, an increase of cell adhesion to Fn or Ln, and a decrease in cell migration and invasion through matrigel. These phenotypes bore similarity to those of the 7721 cells transfected with nm23-H1. Our findings indicate that the down-regulation of GnT-V by nm23-H1 contributes to the alterations in metastasis-related phenotypes, and is an important molecular mechanism of metastasis suppression mediated by nm23-H1.

Modulation of the basal activity of phosphatidylinositol-3-kinase/protein kinase B signaling pathway in human hepatocarcinoma cells

The modulation of GnT-V activity by signaling molecules in PI-3-K/PKB pathway in human hepatocarcinoma cell line 7721 was studied. GnT-V activity was determined after the transfection of sense or antisense cDNA of PKB into the cells, as well as the addition of activators, specific inhibitors, and the antibodies to the enzyme assay system or culture medium. It was found that the basal activity of GnT-V was up regulated by the sense and down regulated by the antisense cDNA of PKB transfected into 7721 cells. GnT-V was activated by PIP2, PIP3 or GTPgamma[S] added to the assay system, and the activation of PIP2 or GTPgamma[S] was abolished by LY2940002, a specific inhibitor of PI-3-K, but the activation of PIP3 was not attenuated by LY2940002. In addition, GnT-V activity in cultured parental or H-ras transfected cells was inhibited by the antibody against PKB or PI-3-K. These findings demonstrated the involvement of PI-3-K/PKB signaling pathway in the regulation of GnT-V. Moreover, ET18-OCH3, an inhibitor of Raf translocation and PI-PLC enzyme, which produces the activator of PKC, as well as the antibodies against Raf-1 or MEK also inhibited GnT-V activity in the parental and H-ras transfected cells. The inhibitory rates, however, were less in the transfected cells than those in the parental cells. These results reveal that in parental and H-ras transfected 7721 cells, the basal activity of GnT-V is also regulated by the Ras/Raf-1/MEK/MAPK cascade in addition to PI-3-K/PKB signaling pathway. The significance of these two pathways in the regulation of GnT-V and their relations to the activation of PKC previously reported by our laboratory (Ju TZ et al., 1995 Glyconjugate J 12, 767-772) was discussed.

Effects of H-ras and v-sis overexpression on N-acetylglucosaminyltransferase V and metastasis-related phenotypes in human hepatocarcinoma cells

Oncogenes and N-acetylglucosaminyltransferase (GnT-V) are both commonly associated with carcinogenesis and metastasis. In order to elucidate the relationship between oncogenes and GnT-V, two oncogenes, H-ras and v-sis/PDGF (platelet-derived growth factor), were selected, and the effects of their overexpression on GnT-V in 7721 human hepatocarcinoma cells were investigated. The results showed that the over expression of H-ras or v-sis/PDGF-B up-regulated the activities of GnT-V to various degrees in the transfected cells. In H-ras- and PDGF-B-overexpressing cells, the activity of GnT-V was up-regulated to double the normal value. The transient expression of v-sis, which produces a protein almost identical to PDGF-B, stimulated the GnT-V activity by 80.3%, and the effect was more pronounced (increased by 182.5%) in 7721 cells with stable expression of v-sis. The stimulating effect was entirely abolished by treatment with PDGF-B antibody. The staining of asparagine-linked glycans (N-glycans) in the H-ras- and v-sis-overexpressing 7721 cells was intensified when horseradish peroxidase-labeled leucoagglutinating phytohemogglutinin was used as a probe, indicating the increased content of beta1,6GlcNAc branching on the N-glycans. The enhancement of GnT-V mRNA expression was also observed in H-ras- and v-sis- overexpressing cells, indicating that H-ras and v-sis regulated GnT-V via the transcription of GnT-V mRNA and the synthesis of GnT-V protein. The cells overexpressing H-ras and v-sis displayed some changes in metastasis-related phenotypes, including acceleration of cell growth, decline of cell adhesion to fibronectin, and an increase of cell adhesion to laminin, as well as increased invasiveness through Matrigel. These results indicated that the alteration of cell adhesion and invasion induced by oncogenes is closely related to the up-regulation of GnT-V activity and its product, beta1,6GlcNAc branching in N-glycans on the cell surface.

Opposing changes in N-acetylglucosaminyltransferase-V and -III during the cell cycle and all-trans retinoic acid treatment of hepatocarcinoma cell line

The changes in N-acetylglucosaminyltransferase-V and -III (GnT-V, GnT-III) during the cell-cycle of synchronized 7721 human hepatocarcinoma cell line were investigated. Using an HPLC method to assay GnT and flow cytometry (FCM) for cell cycle analysis, it was found that GnT-V showed the highest activity, but GnT-III reached the lowest activity when G(2)/M cells were most abundant. In contrast, GnT-V declined to the minimum while GnT-III elevated to maximum when G(0)/G(1) cells were most predominant. The opposing changes were more obvious when the activities of GnT-V and GnT-III were expressed as relative activities (activity of GnT-V or GnT-III/the sum of activities of GnT-V plus GnT-IV plus GnT-III). These opposing changes of GnT-V and GnT-III during the cell cycle might result from the different regulatory mechanisms of GnT-V and GnT-III expression in the cell cycle. The alterations in the structures of cell surface N-glycans were compatible with the changes of the activities of GnTs. The results from immunocytochemistry and Northern blot showed that the protein and mRNA contents of GnT-V were not significantly changed during the cell cycle. The activity of a cell cycle regulating protein kinase, p34(cdc2) kinase, correlated to the activity of GnT-V. These findings suggested that the change of GnT-V activity in cell cycle was not the consequence of the alteration of gene transcription or enzyme protein synthesis, but might be caused by the post-translational regulation. The decrease in GnT-V and the corresponding increase in GnT-III activities were also found after the cells were treated with all-trans retinoic acid (ATRA), and the mechanism of this might be different from that in the cell cycle.

Increased susceptibility to apoptosis of human hepatocarcinoma cells transfected with antisense N-acetylglucosaminyltransferase V cDNA

The antisense cDNA of N-acetylglucosaminyltransferase V (GnT-V, EC 2. 4.1.155) was constructed as pcDNA3/GnT-V-AS plasmid and transfected into 7721 cells, a human hepatocarcinoma cell line. The transfection was confirmed with Northern blot. By using HPLC and HRP-lectin staining, it was found that the cells transfected with pcDNA3/GnT-V-AS (GnT-V-AS/7721) expressed less GnT-V activity and beta-1,6-GlcNAc branching in the cell glycoproteins compared with the cells mock-transfected with the vector pcDNA3 (pcDNA3/7721). The growth rate of GnT-V-AS/7721 was decreased in serum-containing medium, while the cell death was accelerated in serum-free medium. The GnT-V-AS/7721 cells were more susceptible to the apoptosis induced by ATRA than the mock-transfected cells. This was evidenced by the obvious appearance of a hypoploid sub-G(1) fraction in the DNA histogram using FCM analysis, the more condensed new moon-type nuclei under morphological observation, and the more intensive TUNEL reaction for assaying the fragmented DNA. At the same time as GnT-V down-regulation by GnT-V-AS, an increase of another N-aceylglusaminyltransferase, GnT-III (EC 2.4.1.144), was observed, and the biological significance of this finding was discussed.

[Changes with cell cycle of N-acetylglucosaminyl transferase III, IV and V in 7721 human hepatocarcinoma cells]

In order to investigate the changes of N-acetylglucosaminyl transferase (GlcNAc-T) III, IV and V in cell cycle, the synchronization of 7721 human hepatocellular carcinoma cells was performed using serum hunger method. The percentages of cells in different phases during cell cycle were measured by flow cytometry (FCM) and the cell cycle was checked by determining the activity of cellular p34cdc2 kinase. It was found that the activities of GlcNAc-T III increased in G0/G1 cell peak phase and had correlation with the cell percentage of G0/G1 phase (r = 0.760, P < 0.05), while GlcNAc-T V showed the highest activity when G2/M cells were most abundant and had an apparent correlation with the cell percentage of G2/M phase (r = 0.868, P < 0.001). The changes of GlcNAc-T IV activity seemed not related to the cell cycle. The changes in opposite directions of relative activities (percentage of total GlcNAc-T III, IV, V) of GlcNAc-T III and GlcNAc-T V were observed during cell cycle (r = -0.951, P < 0.001), suggesting that these two enzymes might be regulated differently and functioned oppositely in the cells: GlcNAc-T V may be related to the proliferation of 7721 cells, while GlcNAc-T III may be related to the non-mitotic silence phase of the cells, or, it may be a factor against proliferation. Immunohistochemical results showed that the protein content of GlcNAc-T V was not significantly changed during cell cycle, and had no correlation with the activity of GlcNAc-T V, suggesting that the changes of GlcNAc-T V activity in cell cycle might not be resulted from the alteration of enzyme protein synthesis. The correlation between the activities of GlcNAc-T V and p34cdc2 kinase (r = 0.752, P < 0.05) was observed in cell cycle, implicating that GlcNAc-T V might possibly be regulated by p34cdc2 kinase.

Clinical significance of serum S100 in metastatic malignant melanoma

The clinical significance of serum S100 was assessed in comparison to neuron-specific enolase (NSE) in 126 patients with malignant melanoma: 80 patients with clinical stage I/II, 23 patients with stage III and 23 patients with stage IV according to the criteria of the American Joint Committee on Cancer (AJCC). Using cut-off values of 0.15 microgram/l for S100 and 12.5 micrograms/l for NSE, the sensitivity was found to be 1.3% (1/80) for S100 and 8.75% (7/80) for NSE in patients with stage I/II, 8.7% (2/23) for S100 and 13% (8/23) for NSE in patients with stage III, and 73.9% (17/23) for S100 and 34.8% (8/23) for NSE in patients with stage IV disease (P < 0.05). In 6 patients with stage III/IV tumours, serial measurement of serum S100 and NSE was performed. A rise of serum S100 indicated progression of the disease; a decline indicated response to treatment. Our preliminary results support the value of serum S100 as an adjunct to the clinical staging and monitoring of metastatic malignant melanoma.

Clinical significance of serum S100 in metastatic malignant melanoma

The clinical significance of serum S100 was assessed in comparison to neuron-specific enolase (NSE) in 126 patients with malignant melanoma: 80 patients with clinical stage I/II, 23 patients with stage III and 23 patients with stage IV according to the criteria of the American Joint Committee on Cancer (AJCC). Using cut-off values of 0.15 micrograms/l for S100 and 12.5 micrograms/l for NSE, the sensitivity was found to be 1.3% (1/80) for S100 and 8.75% (7/80) for NSE in patients with stage I/II, 8.7% (2/23) for S100 and 13% (8/23) for NSE in patients with stage III, and 73.9% (17/23) for S100 and 34.8% (8/23) for NSE in patients with stage IV disease (P < 0.05). In 6 patients with stage III/IV tumours, serial measurement of serum S100 and NSE was performed. A rise of serum S100 indicated progression of the disease; a decline indicated response to treatment. Our preliminary results support the value of serum S100 as an adjunct to the clinical staging and monitoring of metastatic malignant melanoma.

[Leptotrombidium (L.) scutellare as the transmitting vector of tsutsugamushi disease of autumn-winter type in Jiangsu Province]

In 1986, epidemic of tsutsugamushi disease of autumn-winter type was found in Jiangsu province. To clarify the vector of this disease, we carried out a series of studies in 1986-1992. Leptotrombidium (L.) scutellare was found to be a dominant species of chigger mite on rats in the endemic areas and its seasonal distribution was correlated with the incidence of tsutsugamushi disease in inhabitants. This mite could naturally be infected by Rickettsia tsutsugamushi, and R. tsutsugamushi could be transmitted via biting and transovarial transmission. Specific antibodies could be detected in the sera of mice bitten by the mites or inoculated with the suspension of mites. Serological typing of the sera of mice was of Gilliam type. The above results demonstrate that L. (L.) scutellare can serve as transmitting vector of tsutsugamushi disease of autumn-winter type.