Biological characteristics of Escherichia coli phage and Staphylococcus aureus phage isolated from sewage / 西安交通大学学报(医学版)

【Objective】 Escherichia coli phage (ECP) and Staphylococcus aureus phage (SAP) isolated from sewage were used as research objects, and their biological characteristics were analyzed to provide new experimental materials for the application of phages. 【Methods】 ECP and SAP were purified and cultured by double-layer agar method. Then a series of biological characteristics of these two phages were preliminarily analyzed by electron microscope observation, optimal multiplicity of infection (MOI) test, one-step growth curve test, temperature, pH, chloroform and ultraviolet sensitivity tests, respectively. 【Results】 The results of biological characteristics showed that ECP and SAP were both virulent phages, belonging to myoviridac family. Their optimal MOI was 10-1, and they had strong resistance to ultraviolet light. The cleavage volume of ECP was 76.3 PFU/cell, while that of SAP was 8.3 PFU/cell. ECP had a wide range of temperature tolerance and could stably survive at 30-50 ℃, while SAP was more sensitive to temperature and could be completely inactivated at 50 ℃ for 1 h. ECP could maintain a good lysis activity in the range of pH 5-11, while SAP in the range of pH 6-9. ECP had strong resistance to chloroform and was non-membranous phage, while SAP was more sensitive to chloroform and was a membranous phage. 【Conclusion】 ECP and SAP are both virulent phages and have strong resistance to ultraviolet light. The lysability, temperature, pH, and chloroform tolerance of ECP are stronger than those of SAP.

The effects of varies osmotic pressure induced by adding fluoride into the medium on the biological characteristic of ameloblast / 西安交通大学学报(医学版)

Objective: To explore the effects of varies osmotic pressure induced by adding fluoride into the medium on the biological characteristic of ameloblast.Methods: Ameloblasts were cultured in vitro on the fifth day were seeded and purified. DMEM medium containing different concentrations of NaF (0, 42, 84 mg/L), NaCl (58.5 and 117 mg/L), glycerol (0.05 and 0.09 mg/L) and sorbitol (1 and 1.5 mg/L) was added into the cells, which were then cultured for 48 hours. The survival and proliferation of ameloblasts in different groups were detected by MTT. The apoptosis rate was measured by flow cytometry and the expressions of CK14 and KLK4 by Real-time PCR. Results: MTT showed that with the increase of osmolality, cell proliferation decreased; however, the most obvious one was in NaF group. Streaming apoptosis detection showed that with the increase of osmolality, the apoptosis rate of cells increased, which was most obvious in NaF group. Real-time PCR showed that the mRNA expressions of CK14 and KLK4 decreased with the increase of osmolality, and that they were lower in NaF 42 mg/L group than in the other control groups. Results: The change in osmotic pressure of the medium affects the proliferation, apoptosis and mRNA expression of ameloblasts. The biological change of ameloblasts cultured in medium containing different concentration of NaF is mainly due to the toxic effects of fluoride ions.

Study on biological characteristics: reproduction and viability of Biomphalaria glabrata as an intermediate host of Schistosoma mansoni / 中国血吸虫病防治杂志

Objective To compare the difference of fertility of Biomphalaria glabrata snails between self-fertilization and cross-fertilization and to observe the circadian rhythm of laying eggs, the effect of light on laying eggs and the tolerance of the snail to water and food deficiency, so as to provide the evidence for control and elimination of B. glabrata snails in the field. Methods Under laboratory conditions, a single B. glabrata egg for self-fertilization was separated and hatched individually, and young snails were raised in different plastic boxes individually. The eggs for cross-fertilization were hatched and the young snails were fed in the same plastic box. The ability of spawn, the development of the eggs, and the number of snails growing from young to adult snails were compared between the self-fertilization and cross-fertilization. The snails were in the water under four environments, all day illumination, all day without illumination, daytime lighting and night without illumination, and daytime without illumination but night lighting. The eggs were collected and counted daily. The circadian rhythm of spawn and the effect of illumination on spawn were observed. The adult snails were divided into 6 groups and exposed to the environments with relative humidity of 0, 65%, 87% and 100%, respectively. The survival rates of the adult snails exposed to the different environments after different time were observed. The adult snails were placed at 25 °C in the oven to remove water content from the soft body of snails. When the dehydration rates of the soft bodies achieved 10%, 20%, 30%, 40%, 50%, 52%, 55%, 57%, 60%, and 70% respectively, the survival rates of the adult snails exposed to the oven were observed. Results In the 25 °C water, the average laying egg number for 15 days per snail was (8.77 ± 16.92) eggs/snail in the self-fertilization snail. The average laying egg number for 15 days per snail was (149.71 ± 142.28) eggs/snail in the cross-fertilization snails. There was a significant difference between the self-fertilization snail and cross-fertilization snail (t = 0.999 999, P < 0.01). The hatching rate and reproductive maturation rate of the self-fertilization snails and cross-fertilization snails were 50.1% and 78.9%, and 19.3% and 3.8%, respectively, There was a significant difference (the hatching rate: χ2 = 18.18, P < 0.01, the reproductive maturation rate: χ2 = 11.83, P < 0.01) . In the natural environment of daytime with illumination and nighttime with darkness, the amount of laying 20 eggs of B. glabrata snail was (944.07 ± 392.53) eggs/day during a whole day, among them the amount of laying eggs during daytime account for 10.1% and the amount of laying eggs during nighttime account for 89.9%, and the laying egg was given priority to with the night. The above results suggested that the dark environment was conducive to B. glabrata snails to lay eggs. The above results suggested that light can promote the increase of spawning of B. glabrata. When B. glabrata was exposed to the environments with the relative humidity of 0, 65%, 87% and 100% at 25 °C, respectively, and the longest survival times of snails were 7, 70, 150 d and 100 d, respectively. In the 25 °C water, the snails could survive for 50 days without food. The adult snails were placed at 25 °C in the oven to remove water content from the soft body of snails. When the dehydration rates of the soft bodies achieved 10%, 20%, 30%, 40%, 50%, 52%, 55%, 57%, 60%, and 70% respectively, the survival rates of the adult snails exposed to the oven were 100%, 100%, 100%, 100%, 70%, 30%, 0, 0, 0 and 0, respectively. Conclusions B. glabrata can achieve the reproductive process by cross-fertilization or self-fertilization. There is a significant difference in reproductive ability between the cross-fertilization snail and self-fertilization snail, cross-fertilization is stronger than self-fertilization, but the rate of reproduction in the self-fertilization is higher than that in the cross-fertilization. It is indicated that B. glabrata that survive after the dry season plays an important role in the maintenance of local snail populations and transmission of schistosomiasis mansoni.

Study on biological characteristics: reproduction and viability of Biomphalaria glabrata as an intermediate host of Schistosoma mansoni / 中国血吸虫病防治杂志

Objective To compare the difference of fertility of Biomphalaria glabrata snails between self-fertilization and cross-fertilization and to observe the circadian rhythm of laying eggs, the effect of light on laying eggs and the tolerance of the snail to water and food deficiency, so as to provide the evidence for control and elimination of B. glabrata snails in the field. Methods Under laboratory conditions, a single B. glabrata egg for self-fertilization was separated and hatched individually, and young snails were raised in different plastic boxes individually. The eggs for cross-fertilization were hatched and the young snails were fed in the same plastic box. The ability of spawn, the development of the eggs, and the number of snails growing from young to adult snails were compared between the self-fertilization and cross-fertilization. The snails were in the water under four environments, all day illumination, all day without illumination, daytime lighting and night without illumination, and daytime without illumination but night lighting. The eggs were collected and counted daily. The circadian rhythm of spawn and the effect of illumination on spawn were observed. The adult snails were divided into 6 groups and exposed to the environments with relative humidity of 0, 65%, 87% and 100%, respectively. The survival rates of the adult snails exposed to the different environments after different time were observed. The adult snails were placed at 25 °C in the oven to remove water content from the soft body of snails. When the dehydration rates of the soft bodies achieved 10%, 20%, 30%, 40%, 50%, 52%, 55%, 57%, 60%, and 70% respectively, the survival rates of the adult snails exposed to the oven were observed. Results In the 25 °C water, the average laying egg number for 15 days per snail was (8.77 ± 16.92) eggs/snail in the self-fertilization snail. The average laying egg number for 15 days per snail was (149.71 ± 142.28) eggs/snail in the cross-fertilization snails. There was a significant difference between the self-fertilization snail and cross-fertilization snail (t = 0.999 999, P < 0.01). The hatching rate and reproductive maturation rate of the self-fertilization snails and cross-fertilization snails were 50.1% and 78.9%, and 19.3% and 3.8%, respectively, There was a significant difference (the hatching rate: χ2 = 18.18, P < 0.01, the reproductive maturation rate: χ2 = 11.83, P < 0.01) . In the natural environment of daytime with illumination and nighttime with darkness, the amount of laying 20 eggs of B. glabrata snail was (944.07 ± 392.53) eggs/day during a whole day, among them the amount of laying eggs during daytime account for 10.1% and the amount of laying eggs during nighttime account for 89.9%, and the laying egg was given priority to with the night. The above results suggested that the dark environment was conducive to B. glabrata snails to lay eggs. The above results suggested that light can promote the increase of spawning of B. glabrata. When B. glabrata was exposed to the environments with the relative humidity of 0, 65%, 87% and 100% at 25 °C, respectively, and the longest survival times of snails were 7, 70, 150 d and 100 d, respectively. In the 25 °C water, the snails could survive for 50 days without food. The adult snails were placed at 25 °C in the oven to remove water content from the soft body of snails. When the dehydration rates of the soft bodies achieved 10%, 20%, 30%, 40%, 50%, 52%, 55%, 57%, 60%, and 70% respectively, the survival rates of the adult snails exposed to the oven were 100%, 100%, 100%, 100%, 70%, 30%, 0, 0, 0 and 0, respectively. Conclusions B. glabrata can achieve the reproductive process by cross-fertilization or self-fertilization. There is a significant difference in reproductive ability between the cross-fertilization snail and self-fertilization snail, cross-fertilization is stronger than self-fertilization, but the rate of reproduction in the self-fertilization is higher than that in the cross-fertilization. It is indicated that B. glabrata that survive after the dry season plays an important role in the maintenance of local snail populations and transmission of schistosomiasis mansoni.

Biological characteristics of human bone marrow mesenchymal stem cells in the microenvironment of rabbit bladder acellular matrix graft / 西安交通大学学报(医学版)

Objective: To explore the effects of the microenvironment of rabbit bladder acellular matrix graft (BAMG) on proliferation, cell surface markers, and molecular protein level of human bone marrow mesenchymal stem cells (hBMSCs). Methods: We prepared BAMG immersion fluid medium and detected its effect on the proliferation of hBMSCs by MTT method. The expressions of CD44, CD45, CD73 and PDGFRβ were detected by flow cytometry. The expressions of PPAR, OCN and α-SMA were detected by RT-PCR, and the expression of OCT was detected by Western blot. Results: hBMSCs had good compatibility with BAMG. The MTT method showed that BAMG and BAMG immersion medium did not affect the proliferation capacity of hBMSCs. The surface of hBMSCs cells cultured with immersion fluid still expressed CD44, CD73 and PDGFRβ, but not CD45. RT-PCR showed that OCN, PPAR, and α-SMA were all expressed. Western blot test also showed the positive expression of OCT-4. Conclusion: hBMSCs can still keep their original biological characteristics in the microenvironment of rabbit BAMG. It can be the seed cells and combined substrate materials for urinary system tissue engineering.

Interspecific hybridization of Schistosoma and its significance / 中国血吸虫病防治杂志

Schistosomiasis is one of zoonoses (diseases that are naturally transmitted between vertebrate animals and human),and it is widespread in tropical and sub-tropical regions. It is one of the important infectious diseases that the World Health Organization plans to eliminate. Hybridization within Genus Schistosoma is an emerging public health concern in our changing world.Schistosoma spp. are dioecious trematode, in which there are lots of species infecting human and animals. Several schistosome species also overlap in their geographical and host range, which allows male and female schistosomes of different species to pair within their definitive hosts. The hybridization among different species and the production of dominant hybrid species and changes of their biological characteristics, such as host selectivity, fertility and infectivity, can lead to the evolution of schistosoma species, regional distribution of the population, the changes of epidemic patterns, and pathogenicity to human and animals, and all of them have an impact on the global schistosomiasis elimination plan.

Isolation, biological characteristics and genomic safety assessment of drug-resistant Klebsiella pneumoniae phage JD902 / 上海交通大学学报（医学版）

Objective • To screen for a bacteriophage of a drug-resistant Klebsiella pneumoniae strain and assess its eligibility to be incorporated into the Klebsiella bacteriophage library. Methods • A drug-resistant Klebsiella pneumoniae strain isolated from a patient with urinary infection was used as the host strain. Phage screening was carried out in environmental sewage, and the bacteriophage was isolated, purified, characterized and sequenced. Safety evaluation was also conducted based on the genome sequence. Results • A drug-resistant Klebsiella pneumoniae bacteriophage was isolated and designated as JD902, which belonged to Caudovirales. The burst size was 88 pfu/cell, and it could maintain good activity in pH range 4.0-11.0. Genomic analysis demonstrated that it did not carry any antibiotic resistance genes and virulence factor genes. Conclusion • JD902 is a virulent phage with high stability and safety in vitro. It can be incorporated into bacteriophage library for clinical treatment.

Serotypes of duck Escherichia coli and strain selection for vaccine / 中国人兽共患病学报

In order to obtain the serotype distribution of E.coli from duck and to screen the vaccine bacterial strains,the serotype identifications and biological characteristics of E.coli were analyzed in recent years from Shandong,Hebei and other areas of commercial duck field;selections of vaccine strains were detected by the virulence and immunogenicity.Totally 44 isolated bacterial strains of E.coli from duck were identified to a total of six serotypes:O78,O93,O76,O2,O92 and O32.The O78 serotype was the dominant serotype,accounting for 56.8％ (25/44);O93 serotype for 15.9％ (7/44) according to bacterial Oantigen typing.The strain SD (O78 serotype) was confirmed to have strong virulence and good immunogenicity.The O78,O93 and O76 are the dominant serotypes of duck E.coli in the study areas.The SD strain could be used as the candidate for the next development of inactivated vaccine.

Culture and characterization of spontaneous ascites cells isolated from Mi-crotus fortis / 中国血吸虫病防治杂志

Objective To isolate and culture the spontaneous ascites cells from Microtus fortis under artificial conditions, so as to investigate the molecular mechanism at the cell level. Methods The cells were isolated from spontaneous ascites of M. fortis artificially bred for 90 d,and were cultured and observed under a microscope. The differences of ascites cells among nor?mal,spontaneous ascites and schistosomiasis infected samples of M. fortis were compared. The lesion of tissue was observed si?multaneously. Results There were no obvious organ tissue lesions in M. fortis with spontaneous ascites,and the number and types of cells in peritoneal fluid were irregular and significantly changed. With the extension of culture time ,the colonies ap?peared and there were a large number of vacuole?like cells in the cultured medium and sequentially presenting proliferation ,de?formation,disintegration and the fiber?like changes and could be passaged 3-4 d only. Conclusion The cells from M. fortis with spontaneous ascites are similar to its abdominal cavity cells after infection of Schistosoma japonica.

Experimental Life History and Biological Characteristics of Fasciola gigantica (Digenea: Fasciolidae)

This study was conducted to investigate the life history, morphology, and maturation of larval stages and adult worms of Fasciola gigantica in experimental mice. Lymnaea auricularia rubiginosa was used as the intermediate host, and Oryza sativa was used for encystment of the metacercariae, while Mus musculus was used as the definitive host for maturation study. Fresh eggs from the gall bladder of water buffaloes fully developed into embryonated ones and hatched out at days 11-12 after incubation at about 29masculineC. Free-swimming miracidia rapidly penetrated into the snail host, and gradually developed into the next larval stages; sporocyst, redia, and daughter redia with cercariae. Fully-developed cercariae were separated from the redia and shed from the snails on day 39 post-infection (PI). Free-swimming cercariae were immediately allowed to adhere to rice plants, and capsules were constructed to protect metacercariae on rice plants. Juvenile worms were detected in intestines of mice at days 3 and 6 PI, but they were found in the bile duct from day 9 PI. Juvenile and adult flukes were recovered from 16 mice experimentally infected with metacercariae, with the average recovery rate of 35.8%. Sexually mature adult flukes were recovered from day 42 PI. It could be confirmed that experimentally encysted metacercariae could infect and develop to maturity in the experimental host. The present study reports for the first time the complete life history of F. gigantica by an experimental study in Thailand. The obtained information can be used as a guide for prevention, elimination, and treatment of F. gigantica at environment and in other hosts.

Experimental Life History and Biological Characteristics of Fasciola gigantica (Digenea: Fasciolidae)

This study was conducted to investigate the life history, morphology, and maturation of larval stages and adult worms of Fasciola gigantica in experimental mice. Lymnaea auricularia rubiginosa was used as the intermediate host, and Oryza sativa was used for encystment of the metacercariae, while Mus musculus was used as the definitive host for maturation study. Fresh eggs from the gall bladder of water buffaloes fully developed into embryonated ones and hatched out at days 11-12 after incubation at about 29masculineC. Free-swimming miracidia rapidly penetrated into the snail host, and gradually developed into the next larval stages; sporocyst, redia, and daughter redia with cercariae. Fully-developed cercariae were separated from the redia and shed from the snails on day 39 post-infection (PI). Free-swimming cercariae were immediately allowed to adhere to rice plants, and capsules were constructed to protect metacercariae on rice plants. Juvenile worms were detected in intestines of mice at days 3 and 6 PI, but they were found in the bile duct from day 9 PI. Juvenile and adult flukes were recovered from 16 mice experimentally infected with metacercariae, with the average recovery rate of 35.8%. Sexually mature adult flukes were recovered from day 42 PI. It could be confirmed that experimentally encysted metacercariae could infect and develop to maturity in the experimental host. The present study reports for the first time the complete life history of F. gigantica by an experimental study in Thailand. The obtained information can be used as a guide for prevention, elimination, and treatment of F. gigantica at environment and in other hosts.

Study on biological characteristics of cypermethrin-resistant and-suscepti-ble strains of Aedes albopictus at different temperatures / 中国血吸虫病防治杂志

Objective To study the biological characteristics of cypermethrin?resistance strain and?susceptible strain of Ae?des albopictus under different controlled temperatures in the laboratory. Methods The two strains were raised at three different temperatures 20 25℃and 28℃respectively and the biological characteristics of the two mosquito strains such as reproduc?tion development and life expectancy were observed and recorded in the laboratory. Results The life expectancy of both strains became shorter as the temperature raised and the resistant strain 69.37%± 0.01% 77.04%± 0.07% lived shorter than the susceptible strain 85.24%±0.03% 88.23%±0.05% in average. Under 25℃ the hatching rate of resistant strain decreased by 25.88% and the pupation rate decreased by 11.18%. In the three temperatures all the life expectancy expanded as the tem?perature went up the periods for the susceptible strain were 19.75±0.10 23.65±0.07 d and 25.08±0.08 d under 28 25℃and 20℃. While life expectancy for the resistant strain decreased to 17.21±0.09 20.95±0.09 22.58±0.10 d. Under the same tem?perature the development timing of the resistance strain was longer than that of the susceptible strain and the period was the longest under 28 ℃ 156.2 h 137.1 h . In the three temperatures all the development periods expanded as the temperature went up the susceptible and resistant larvae developed 137.1 d and 163.3 d 247.7 d and 156.2 d 182.3 d and 263.2 d under 28 25℃and 20℃. The differences show statistic significance P<0.05 . Conclusion The resistance of A. albopictus to cy?permethrin results in the decrease of adaptability to the environment change and the disadvantage of reproduction at different temperatures.

Biological characteristics and probiotic effect of Leuconostoc lactis strain isolated from the intestine of black porgy fish

A strain of lactic acid bacteria, Leuconostoc lactis, was isolated from the intestinal tract of black porgy, Sparus macrocephalus, and identified by conventional biochemical characteristics and 16S rDNA gene sequence analysis. The isolated strain had the ability of bile tolerance and resistance to low pH, and survived well in the trypsinase and pepsin solution. But the highly concentrated dose of trypsinase and pepsin affect the viability of the isolated strain. The isolate was resistant to several antibiotics, including Cephalothin, Ceftriaxone, Imipenem and Tobramycin. The isolate could autoaggregate itself and coaggregate with other bacteria in vitro. The autoaggregation percentage increased to 23.29% after 20 h of incubation. The percentage of coaggregation were respectively 31.21%, 29.44%, 10.74%, 16.49%, 24.36%, 24.41% and 20.99% for Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli O157, Salmonella typhimurium, Shigella, Staphylococcus aureus and Proteusbacillus vulgaris after 20 h incubation of a mixed suspension. The supernatant of the strain inhibited the growth of several pathogens, such as V.parahaemolyticus, Vibrio harveyi, Vibrio alginolyticus, Staphylococcus aureus, Escherichia coli O157, Salmonella typhimurium, Bacillus subtilis, Proteusbacillus vulgaris and Shigella. These results indicated that the isolate, Leuconostoc lactis, might be an attractive candidate for perspectival strain for probiotics in marine aquaculture.

HIV prevalence in suspects attending Sir Sunder Lal Hospital

<p><b>OBJECTIVE</b>To assess the sero-positivity rate of HIV infection among clinically suspected subjects of reproductive age group (15-49 years), biological and behavioral characteristics of the subjects gender specific variation of sero-positivity rate, and the differentials of the sero-positivity rate for the history of blood transfusion or blood products or other organs, history of needle exposure and symptoms of morbidity.</p><p><b>METHODS</b>Study is based on the retrospective data of the calendar year 2005 obtained from Voluntary Counseling and Testing Centre (VCTC) (now renamed as ICTC), Department of Microbiology, I.M.S., B.H.U., Varanasi. These cases were either referred by the consultants of different OPD'S of Sir Sunderlal Hospital or came voluntarily for knowing their HIV status. About 2-3 mL of blood samples were collected in a plain vial and tested for HIV status by strategy II/III as per WHO/NACO guidelines.</p><p><b>RESULTS</b>Overall sero-positivity of HIV was 15.3% (18.1% in males and 12.2% in females) which increased 6-7 folds in the age group 35-49 years as compared to 15-24 years in both the sexes. Sero-positivity rate in male migrants was 43.1%, while in female migrants it was 18.7%. The history of multiple sexual contacts was about 3 times higher in males as compared to females; predominantly it was very high in male migrants (67.7%) as compared to male non-migrants (15.8%). History of multiple sexual contacts was not uncommon in females and it was 25.0% in female migrants and 9.7% in non-migrant females. The sero-positivity rate with the history of multiple sexual contacts was 45.4% in males and 60.3% in females, while without history of multiple sexual contacts these were only 2.8% and 5.3% respectively. Sero-positive cases had on an average 3.6±1.7 various morbidity symptoms as compared to 0.7±1.1 in sero-negatives. It is to be noted that sero-positivity rate was more in those females who seemed apparently healthy compared to those presenting with some of the symptoms; vice versa, in males presenting with some symptoms HIV infection was 7 times higher than those without symptoms.</p><p><b>CONCLUSIONS</b>The findings indicate a high sero-positivity among both the genders. Multiple heterosexual contacts, especially, in migrants are the main root of transmission of HIV. These are causing spread of HIV to their spouses. The multiple sexual contacts in the society, especially, among non migrant females of this region are indicating the distortion of traditions and cultures which are a serious concern and may lead to HIV infection on the rise. Awareness program to the susceptible group is the need to reduce further spread of HIV.</p>

Observation on several biological characteristics of Eperythrozoon / 中国人兽共患病学报

Some biological properties of eperythrozoon, such as the influence of low temperature on their viability, their infectivity in different kinds of animals and their changes in amount of organisms in vivo were investigated in the present study. The experimental results showed that the viability of eperythrozoon could be maintained at -20 ℃ for 835 days and at 4 ℃ for 205 days. Small rats could be infected by Eperythrozoon suis, while chickens were not infected. The basic regulation on the changes in amount of organisms in animals was expressed by the fact that the percentages of erythrocytes being infected increased rapidly up to 96-98% 2-4 hours after infection, then it dropped down and followed by dropping and re-rising, attaining its climax up to 8 hours after infection. Finally, it reflected a fluctuating cycle of 14-16 hours. This results showed that eperythrozoons can maintain their viability at -20℃ for a long time and they possess relative species specificity to host with a reproduction cycle of 14-16 hours in animal body.

Biological Characteristics of Acid Sensing Ion Channels (ASICs) and Their Modulations / 生物化学与生物物理进展

ASICs are H+-gated novel cation ion channels, which belong to the epithelial sodium channels (NaC/DEG) superfamily. As recent studies focus, ASICs are expected to be pharmacological targets on protecting the neuron from ischemia and damage, improving the ability of memory and study, curing epilepsy and analgesia. It is not until the most recentness that the subunits of ASICs have been cloned. Now, researchers have paid more attention to the distribution, expression, function and modulation of ASICs in the organism.

Study on biological characteristic and conservation of tuniclike psammosilene root / 中华中医药杂志

Objective: To study the endangered mechanism of tuniclike psammosilene root and put forward the conservation ways,so as to provide basis for resources conservation.Methods: Wild on-site inspection was used to study the natural distribution,living condition,biological characteristic,growing adaptability of tuniclike psammosilene root.Results: Tuniclike psammosilene root can grow well in barren,dry and cold circumstances but wetting.The population quantity of tuniclike psammosilene root was reduced largely for destroy of biogeocoenosis.Conclusion: To conserve resources,the exploitation of tuniclike psammosilene root should follow the pattern of planting and finish machining.

Some biological characteristics of China strain of anopheles dirus in laboratory

The eggs of Anopheles dirus originated from China and currently colonized at the National Institute of Malariology, Parasitology and Entomology kept at 24 - 26°C on wet cotton for 20 - 25 days gave hatching rate approximately of 40%. The suitable food for Anopheles dirus larvae consisted of 6g bread powder, 2g green bean powder and 0.5mg vitamin B 1. The appropriate density for rearing An. dirus larvae is 0.4 larva per square centimetre of water surface

Establishment of a novel epithelial cell line from laterally spreading tumor of colon / 解放军医学杂志

Objectives In order to further investigate the biological characteristics and the developmental mechanisms of laterally spreading tumor, a cell line from the primary culture of human colon LST tissue was isolated. After 70 passages, we identified the cells by morphologic, genetic and immunohistochemistry analysis. Results (1) The origin of LST cells is epithelial, and the majority of which were multiform epithelial cells. It displayed an approximately similar growth characteristics of tumor cells. The nest corpus doubling time was 36 hours. (2) The number of chromosome is 42-66. Eighty-five percent of chromosomes were triploid, showing abnormal karyotypes. (3) Immunohistochemistry showed that ESA and CK20 were expressed. (4) The ultrastructure of LST was almost the same as that of a tumor cell. Conclusion A novel LST cell line has been established and named as LST-R1. It facilitates further study of the biological characteristics of LST cells and the development of colon cancer.

In vitro culture and biological characteristics of rat cementoblasts / 实用口腔医学杂志

Objective: To investigate the feasibility of culturing and identifying the cementoblasts in vitro and to study the biological characteristics of rat cementoblasts.Methods: Osteoblasts, PDL fibroblasts and cementoblasts were obtained from alveolar bone and the root surface of rat first molars and cultured with a 2-step method of enzyme digestion/explant technique. Bone osteocalcin(OCN) and alkaline phosphatase(ALP) were detected by quantitative immunohistochemical examination. Alizarin Red S was used to examine the formation of calcified nodules under conditional culture. Results: Primarily cultured cells could be subcultured. Osteoblasts were identified by the expression of OCN and ALP at heigh level, cementoblasts by OCN , PDL fibroblasts by ALP at moderate level, cell clusters/nodules of cementoblasts were observed as the cells approached confluence.Conclusion: Cementoblast-like cells may be cultured in vitro.