Analysis of KIT mutations and c-KIT expression in Chinese Uyghur and Han patients with melanoma.

BACKGROUND: The KIT gene plays an important role in the pathogenesis of malignant melanoma (MM). In recent years, activating mutations in KIT have been recognized as oncogenic. A number of therapies have been established, which provide significant clinical benefits for patients with MM with KIT mutations. Thus, detection of KIT mutations can have profound therapeutic implications. AIM: To investigate KIT gene expression in MMs in Chinese Uyghur and Han patients with mutations in KIT, and to identify the clinical features associated with KIT mutations and c-KIT expression. METHODS: In total, 105 MMs (56 from Uyghur and 49 from Han patients) were selected from patients in the Uyghur Autonomous region. Formalin-fixed, paraffin wax-embedded tumour sections were analysed for c-KIT expression using immunohistochemistry. Exons 11 and 13 of KIT were analysed for the presence of mutations using PCR amplification and DNA sequencing. RESULTS: Of the 105 MMs, 13 (10 Han and 3 Uyghur) were found to have mutations in KIT. Thus, the frequency of KIT mutations in Han patients was significantly higher than that in Uyghur patients (P = 0.02). We detected c-KIT expression in 71.4% and 42.9% of the tumour tissue samples collected from the Uyghur and Han patients, respectively. CONCLUSION: In the Xinjiang Uyghur Autonomous Region in China, chronic sun-induced damage MM is the most prevalent MM among Chinese Uyghur patients, whereas acral and mucosal MMs are the most prevalent in Uyghur patients. Mutations in the KIT gene do not correlate with c-KIT expression.

[Effect of Gastrodia on rotation induced motion sickness in mice].

OBJECTIVE: To observe the effect of Gastrodia on motion sickness induced by rotation in mice. METHOD: Clockwise and anticlockwise accelerated rotations up to 180 degrees/s for 10 min were used to induce symptoms of motion sickness such as condition taste aversion (CTA), decrease of spontaneous locomotion and impaired ability of space identification in water-maze. RESULT: Gastrodia could improve the response of CTA, increase spontaneous locomotion, and enhance the ability of learning and memory in water-maze in mice after the rotation. CONCLUSION: Symptoms of motion sickness induced by rotation could be improved by Gastrodia treatment.

Effects of extracellular products of Vibrio alginolyticus on penaeid prawn plasma components.

The effects of both crude extracellular products (ECP) and a partially purified protease of Vibrio alginolyticus on the plasma components of kuruma prawn (Penaeus japonicus) and tiger prawn (P. monodon) were studied using crossed immunoelectrophoresis (CIE). A component of the plasma, tentatively identified as coagulogen, apparently disappeared after incubation with the ECP, while the amount of a component tentatively identified as haemocyanin decreased. The coagulogen and an unknown component (component 1) in the penaeid plasma showed an increased migration rate after incubation with a partially purified 33 kDa protease of the bacterium. In contrast, incubation with protease had no detectable effect on the amount of haemocyanin. These events may significantly contribute to the pathogenicity of Vibrio alginolyticus in penaeids.

Alkaline serine protease is an exotoxin of Vibrio alginolyticus in kuruma prawn, Penaeus japonicus.

An extracellular lethal toxin produced by Vibrio alginolyticus strain Swy originally isolated from diseased kuruma prawn(Penaeus japonicus) was partially purified by Fast Protein Liquid Chromatography with hydrophobic interaction (Phenyl Sepharose Hig hPerformance) chromatography and gel filtration columns. The toxin is an alkaline serine protease, inhibited by phenyl-methylsulfonyl fluoride (PMSF),and showed maximal activity at pH 10, having a molecular weight of about 33kDa estimated by SDS-PAGE and gel filtration chromatography. In addition, the toxin was also completely inhibited by FeCl2 but partially inhibited by CaCl2, CuCl2, CoCl2,MnCl2, and ZnCl2, and not inhibited by ethylenediaminetetraacetic acid (EDTA), ethylene glycol-bis(beta-amino-ethyl ether)N,N,N',N'-tetraacetic acid (EGTA), iodoacetamide, pepstatin A, sodium dodecylsulfate (SDS), and N-tosyl-l-phenyl-alanine chloromethyl ketone (TPCK). Both the crude extracellular products (ECP) and the partially purified toxin are lethal for kuruma prawn at LD50 values of 0.30 and 0.27 microg protein/g body weight, respectively. The addition of PMSF completely inhibited the lethal toxicity of both the ECP and the partially purified toxin, indicating that this serine protease is a lethal factor produced by the bacterium. The 33-kDa protease is, therefore, suggested to be a new toxic protease produced by V. alginolyticus strain Swy.

Virulence of Vibrio alginolyticus isolated from diseased tiger prawn, Penaeus monodon.

Outbreaks of mass mortality among cultured tiger prawns (Penaeus monodon) with white spotted syndrome (WSS) in the carapace occurred in the summer of 1994 in I-Lan, Taiwan. A swarming strain Val was isolated from hemolymph of the moribund prawns with tryptic soy agar (TSA, supplemented with 1% NaCl, Oxoid) and/or thiosulfate citrate bile salt sucrose (TCBS, Difco) agar. This strain was characterized and identified to be Vibrio alginolyticus. The strain was susceptible to antibiotics such as chloramphenicol, ciprofloxacin, doxycycline hydrochloride, nalidixic acid, oxolic acid, and oxytetracycline while resistant to ampicillin, novobiocin, penicillin G, sulfisoxazole, and sulfonamide. The bacteria and their extracellular products (ECP) were lethal to both tiger prawns (P. monodon) and kuruma prawns (P. japonicus) with LD50 values of 1.13 x 10(5), 2.46 x 10(5) CFU/g, and 0.23, 0.63 micrograms protein/g prawn body weight, respectively.

Isolation and characterization of Vibrio alginolyticus isolated from diseased kuruma prawn, Penaeus japonicus.

Outbreaks of serious mortality among cultured kuruma prawns (Penaeus japonicus) with white spotted syndrome in the carapace occurred in the summer of 1993 in I-Lan, Taiwan. A swarming bacterium, strain Swy, was isolated from the hepatopancreas of the moribund prawns using tryptic soy agar supplemented with 1% NaCl and/or thiosulphate citrate bile salt sucrose agar. This strain was characterized and identified as Vibrio alginolyticus on the basis of a number of biochemical tests. The Swy strain was virulent to both kuruma prawns (P. japonicus) and tiger prawns (P. monodon) with LD50 values of 4.43 x 10(4) and 1.57 x 10(5) cfu g body weight-1, respectively.

A survey of moniliformin contamination in rice and corn from Keshan disease endemic and non-KSD areas in China.

Keshan Disease (KSD) is an endemic heart disease and moniliformin (MF) has been suggested as one of the etiological factors. In this paper, thin layer chromatographic (TLC) and high pressure liquid chromatographic (HPLC) methods were used for the determination of MF in the rice and corn samples collected from KSD areas and non-KSD areas. One hundred and twenty-three rice samples were analyzed and showed MF contamination in only 8 samples (KSD areas: 8.4% positive; non-KSD areas: 2.5% positive) ranging from 73.6 to 265.3 ng/g (mean concentration: KSD areas 156.3 ng/g; non-KSD areas 179.5 ng/g). One hundred and four corn samples in KSD areas and non-KSD areas were determinated by HPLC method, 45.2% samples were contaminated with MF (KSD areas: 81.4%; non-KSD areas: 19.7%) ranging from 52.3 to 1116.0 ng/g (mean concentration: KSD areas 488.9 ng/g; non-KSD areas 457.4 ng/g). The results showed that the contamination of MF in grains were significantly different between rice and corn, but not between the grains from the KSD areas and non-KSD areas, then casting doubt on the role of MF as an etiological factor of KS.

Protective immunity induced by 67 K outer membrane protein of phase I Coxiella burnetii in mice and guinea pigs.

A 67 K outer membrane protein (OMP) isolated from phase I Coxiella burnetii QiYi strain was purified with monoclonal antibodies (MoAb) coupled to CNBr-Sepharose 4B. Chemical analyses of the 67 K protein showed that it contained seventeen kinds of amino acids and no LPS. The immunogenicity and protectivity of the 67 K protein against C. burnetii was evaluated in mice and guinea pigs by in vitro lymphocyte proliferation assay, delayed-type skin test, antibody conversion rate, and immunization and challenge tests. Intraperitoneal injection of the 67 K protein resulted in antibody production against phase I and II whole cell antigens. The anti-67 K antibody conversion rate was found to be 100% in mice and guinea pigs as well. Lymphocytes were responses in vitro to specific antigen. In addition, delayed-type hypersensitivity appeared two weeks after immunization with the 67 K protein. Moreover, 100% of mice and guinea pigs inoculated with the 67 K protein were protected against a challenge with 10(3) ID50 virulent C. burnetii. In conclusion, these results demonstrate that the 67 K OMP elicits in vivo and in vitro both B cell-mediated and T cell-mediated immunity in mice and guinea pigs. Thus the 67 K protein is a candidate for an effective subunit vaccine against Q fever.

Molecular characterization of cloned variants of Coxiella burnetii isolated in China.

To study the molecular properties of Coxiella burnetii phase variants we cloned the phase variants of C. burnetii Qiyi (CBQY) strain by the red plaque technique. Three cloned strains, CBQYIC3 (phase I), CBQYIIC7 (phase II) and CBQYIIC5 (semirough-phase) were analysed by SDS-PAGE, immunoblot assay, plasmid isolation and agarose gel electrophoresis of DNA restriction fragments. The results suggest that the unique phase-dependent substance is a lipopolysaccharide and that most protein components of phase I and phase II cells are shared. No significant differences of DNA restriction fragments were found between clonal isolates of phase I and phase II C. burnetii CBQY strains. A plasmid of approximately 56 Kb was isolated from both phase I and phase II variants indicating that phase variation probably could not be attributed to its presence or absence.

Analysis of proteins and lipopolysaccharides from Chinese isolates of Coxiella burnetii with monoclonal antibodies.

Four Coxiella burnetii isolates in China and two reference strains were compared by SDS-PAGE and immunoblotting. The SDS-PAGE profiles of whole cells and LPS of Chinese isolates Qiyi, Xinqiao, and YS-8 were found closely related to Henzerling strain, and different from the Grita strain. In immunoblot assay of LPS and proteinase K-digested whole rickettsiae minor differences were seen in polysaccharide structure among the Chinese isolates by phase I monoclonal antibody. The present results suggest that the strains reported here may be divided into three groups according to the polysaccharide structure: Xinqiao and Henzerling strains (1), YS-8 and Grita (2), and Qiyi (3).

The reemergence of dengue in China.

In 1978, dengue was reported in China for the first time in 32 years. Since then, epidemics involving hundreds of thousands of people have occurred in Guangdong and Guangxi provinces and on Hainan Island. These epidemics were caused by all four types of dengue virus. Aedes aegypti was the vector in coastal areas, while Aedes albopictus was the vector in inland regions. During these epidemics, case rates were very high (greater than 50%) in some areas. Case-fatality rates were generally less than 0.1% except during the 1986 outbreak on Hainan Island, when the rate was 0.25%. Hemorrhagic disease occurred in both children and adults. On Hainan Island, hemorrhagic disease was more than three times as common in the 1986 outbreak as in the 1980 outbreak; the 1980 outbreak was caused by dengue virus type 3 and the 1986 outbreak by dengue virus type 2. The weight of the evidence suggests that the reemergence of dengue in China resulted from the introduction of the infection by travelers and refugees from areas of Asia where dengue is endemic.

Red plaque formation of Coxiella burnetii and reduction assay by monoclonal antibodies.

A red plaque technique for C. burnetii which utilizes primary chicken embryo cells, is described. Red plaques could be consistently detected as early as 6 days, usually 8 days post inoculation (p.i.), reflecting that C. burnetii proliferated within the phagolysosomes of host cells. Incubation with phase II monoclonal antibodies or inactivated immune sera containing phase I and phase II antibodies or phase II antibodies only, markedly reduced phase II C. burnetii red plaques. On the other hand, red plaques from phase I organisms increased several times when phase I cells were mixed with phase I monoclonal antibodies or inactivated immune sera containing phase I and phase II antibodies. By indirect red plaque reduction assay red plaque production by phase II cells could be reduced as well.

Antigen-specific circulating immune complexes in Coxiella burnetii-infected guinea pigs.

An antigen-specific conglutinin-binding assay was developed with artificial immune complexes of Coxiella burnetii and an enzyme-linked immunosorbent assay for the detection of circulating immune complexes. Sera from guinea pigs infected with C. burnetii were examined by this assay, and the percentages of infected guinea pigs with C. burnetii antigen-specific circulating immune complexes were 71, 93, 74, 65, 49, and 27%, respectively, from the first to sixth week after infection. C. burnetii antigen eluted from circulating immune complexes by acid dissociation was detected by counterimmunoelectrophoresis. The antigen-specific conglutinin binding assay was specific, sensitive, and reproducible for assay of circulating immune complexes.

Epidemiology and ecology of rickettsial diseases in the People's Republic of China.

Since 1949, information on rickettsial diseases in the People's Republic of China has been virtually nonexistent in the West. This is the first comprehensive review of the ecology and epidemiology of Chinese rickettsial diseases to be published outside the People's Republic. At least five rickettsioses exist in China: scrub typhus, murine typhus, epidemic typhus, Q fever, and one or more spotted fever-group (SFG) rickettsioses. Although epidemic typhus has been controlled and scrub typhus has abated in many areas, murine typhus, Q fever, and SFG rickettsiosis are important public health problems. Serologic surveys indicate high prevalences of antibodies to Coxiella burnetii, Rickettsia tsutsugamushi, and SFG rickettsiae in some regions; these rickettsiae have been isolated from humans, arthropods, and animals. Doxycycline has emerged as the best treatment for murine typhus, epidemic typhus, and scrub typhus. China offers both opportunities and challenges for the investigation and alleviation of the problems of rickettsial diseases.