Chinese hamster ovary cells (CHO) are preferable to prokaryotic, yeast or insect cells as hosts for biopharmaceutical production due to the products are more similar to their natural conformation. However, CHO cells confront tremendous difficulties when cultured in large scale such as mal-adaptation to serum-free medium, apoptosis and over-growth without limitation. So in addition to optimizing CHO system in respect of medium, environment and expression vector, modification of CHO cells themselves has drawn more and more attention. Here the main progress in CHO-modification is reviewed.
Animals ; Apoptosis ; genetics ; CHO Cells ; drug effects ; metabolism ; Cell Cycle ; drug effects ; Cell Cycle Proteins ; drug effects ; Cell Division ; drug effects ; Cricetinae ; Genetic Vectors ; genetics ; Transfection

Mammalian cells are prone to apoptosis when cultured in large scale for production of biopharmaceuticals. And this will reduce production duration and result in high cost of production. Apoptosis is triggered by various factors, and delicately regulated by a set of genes. Bcl-2, a component integrated in mitochondria membrane, is an important member of these genes. By maintaining the integrity of mitochondria membrane, Bcl-2 keeps cytochrome C from releasing into cytoplasm, and thus blocks the activation of caspases, and subsequent onset of apoptosis. Over-expression of Bcl-2 has proven to be useful in blocking apoptosis in various cell lines, including CHO, hybridoma, myeloma, lymphoma and insect cells. Ammonia, a metabolite of cultured cells, however, showed apparent pro-apoptosis activity. In living cells, ammonia can be utilized by glutamine synthetase (GS) to synthesize glutamine, and thus lower the concentration of ammonia in medium, and its negative effects. Glutamine is essential to living cells. If not added into medium, glutamine can only be synthesized by GS, which makes GS a qualified selection marker. This marker can be used for gene amplification by adding into medium increased concentration of MSX, an inhibitor of GS. In this study, we over-expressed Bcl-2 using GS amplification in a recombinant CHO cell line stably expressing human interferon-beta. The modified cell line, with higher expression of Bcl-2 and lower production of ammonia, exhibited good anti-apoptosis quality and higher interferon-beta production in continuous culture.
Animals ; Apoptosis ; genetics ; physiology ; Biopharmaceutics ; CHO Cells ; cytology ; metabolism ; Cricetinae ; Cricetulus ; Glutamate-Ammonia Ligase ; genetics ; metabolism ; Interferon-beta ; metabolism ; Models, Genetic ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism

OBJECTIVETo study the morphology and functional character of blood-spleen barrier (BSB) and establish the concept of BSB.

METHODSThirty healthy Wistar rats were studied. Ten rats were injected with 1.5 ml mixed fluid of India ink and physiological saline through the tail vein. Histological changes of the spleen in all animals were observed with light and electron microscopy, including HE, Foot, Masson staining and immunohistochemistry of CD68 and CD34.

RESULTSMost of the carbon particles were within the splenic sinuses in marginal zone but not in the white pulp after 6 h. There was a characteristic distribution of the macrophagocytes, vessel endothelial cell, reticular tissue and collagen fiber in the BSB.

CONCLUSIONSBSB, surrounding the white pulp, is composed of macrophagocytes, marginal-sinus-endothelial cells and their basement membrane, the reticular tissue (reticular cells and reticular fibers) and collagen fibers. The role of BSB is to keep the microenvironment of white pulp stable. It becomes mature while the formation of germinal center of the white pulp. The permeability of BSB changes during its development.

Animals ; Basement Membrane ; ultrastructure ; Endothelial Cells ; ultrastructure ; Female ; Macrophages ; ultrastructure ; Male ; Rats ; Rats, Wistar ; Reticulocytes ; ultrastructure ; Spleen ; blood supply ; ultrastructure

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Biphenyl Compounds ; pharmacology ; Creatinine ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Hypertrophy ; Immunohistochemistry ; Kidney ; metabolism ; pathology ; Male ; Matrix Metalloproteinase 2 ; analysis ; genetics ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; Tetrazoles ; pharmacology ; Tissue Inhibitor of Metalloproteinase-2 ; analysis ; genetics

OBJECTIVETo assess the health effects of dusts in enzyme production plants.

METHODSThe concentration of enzyme-containing dusts, the enzyme and the wheat-containing dusts and their health effects on workers were investigated in three enzyme production plants. Air samples were collected by high volume sampler and personal sampler. Total dust was weighed and its content of enzyme was analyzed by enzyme activity method. Health effects were assessed by the questionnaire, the pulmonary function and the skin prick test.

RESULTSIt was found that the geometric mean of enzyme-containing dust was 8.91 mg/m(3), the industrial enzyme was 1.68 mg/m(3), and the wheat-containing dust was 6.93 mg/m(3). The enzyme-containing dust higher than 20 mg/m(3) caused eye symptoms. The wheat-containing dust at 6.93 mg/m(3) might result in skin and nose symptoms. The sensitization could be observed in enzyme and wheat exposed workers.

CONCLUSIONAdverse effects may arise for the health of the workers if the concentration of enzyme-containing dusts and the wheat-containing dusts is up to a certain limit and it is necessary to make the limit of these indexes.

Adolescent ; Adult ; Albumins ; adverse effects ; Dust ; analysis ; Enzymes ; analysis ; Female ; Health Surveys ; Humans ; Male ; Middle Aged ; Occupational Exposure ; Respiratory Function Tests ; Skin Tests ; Surveys and Questionnaires ; Triticum

OBJECTIVETo identify more effective and less toxic drugs to treat animal toxoplasmosis.

METHODSEfficacy of seven kinds of sulfonamides against Toxoplasma gondii (T. gondii) in an acute murine model was evaluated. The mice used throughout the study were randomly assigned to many groups (10 mice each), which either remained uninfected or were infected intraperitoneally with tachyzoites of T. gondii (strains RH and CN). All groups were then treated with different sulfonamides and the optimal treatment protocol was determined candidates. Sulfadiazine-sodium (SD) was used for comparison.

RESULTSThe optimal therapy involved gavaging mice twice per day with 250 mg/kg bw of sulfachloropyrazine-sodium (SPZ) for five days. Using this protocol, the average survival time and the time-point of 50% fatalities were prolonged significantly compared with SD treatment. Treatment with SPZ protected 40% of mice from death, and the heart and kidney tissue of these animals was parasite-free, as determined by nested-PCR. SPZ showed excellent therapeutic effects in the treatment of T. gondii in an acute murine model and is therefore a promising drug candidate for the treatment and prevention of T. gondii in animals.

CONCLUSIONSIt can be concluded that the effective drug sulfachloropyrazine may be the new therapeutic options against animal toxoplasmosis.

Administration, Oral ; Animals ; Antiprotozoal Agents ; administration & dosage ; DNA, Protozoan ; analysis ; isolation & purification ; Disease Models, Animal ; Female ; Heart ; parasitology ; Kidney ; parasitology ; Mice ; Polymerase Chain Reaction ; Sulfanilamides ; administration & dosage ; Survival Analysis ; Toxoplasma ; drug effects ; genetics ; isolation & purification ; Toxoplasmosis ; drug therapy ; Treatment Outcome

OBJECTIVETo evaluate the protective efficacy of plague subunit vaccine, BALB/c mice, guinea pigs and rabbits were used in this study.

METHODSGroups of mice (10 per group), guinea pigs (14 per group) and rabbits (6 per group) were immunized with F1 + rV270 vaccine, EV76 vaccine and alum adjuvant by intramuscular route, respectively. Serum antibody titres of mice, guinea pigs and rabbits were determined by ELISA and the immunized animals were challenged with 10(6) CFU of Y. pestis strain 141 at the 8th week after the primary immunization.

RESULTSThe immunized mice, guinea pigs or rabbits with subunit vaccine developed anti-F1 IgG titre of 41 587.3 +/- 2.1, 11 543.7 +/- 2.1 or 522.4 +/- 22.4 and elicited statistical anti-F1 IgG titre difference among them (F = 17.58, P < 0.01). The immunized mice, guinea pigs or rabbits with subunit vaccine had anti-rV270 IgG titre of 15 748.7 +/- 1.6, 12.6 +/- 1.4 or 1648.0 +/- 5.0 and induced statistical anti-rV270 IgG titre difference among them (F value was 16.34, P < 0.01). There was significant anti-F1 IgG titre difference among mice, guinea pigs and rabbits immunized with EV76 vaccine that developed anti-F1 IgG titre of 913.4 +/- 4.5, 937.0 +/- 2.0 or 342.0 +/- 12.0 (F = 23.67, P < 0.01), whereas the immunized mice, guinea pigs and rabbits with EV76 vaccine developed anti-rV270 IgG titre of 12.0 +/- 1.0, 447.0 +/- 10.0, 40.0 +/- 11.0 and there was no anti-rV270 IgG titre difference between them (F = 2.20, P = 0.1314). The immunized mice with subunit vaccine developed significantly higher anti-F1 IgG titres than immunized guinea pigs and rabbits (q value was 30.57 and 19.04, respectively, P < 0.01), and there were no anti-F1 IgG titre differences between the immunized guinea pigs and rabbits (q = 0.04, P = 0.8485). The immunized mice with subunit vaccine developed significantly higher anti-rV270 IgG titres than immunized guinea pigs and rabbits (q value was 27.10 and 19.49, respectively, P < 0.01), and there were no anti-rV270 IgG titre differences between the immunized guinea pigs and rabbits with the subunit vaccine (q = 0.25, P = 0.6187). The immunized mice with EV76 elicited higher anti-F1 IgG titres than immunized guinea pigs and rabbits (q value was 40.67 and 29.10, respectively, P < 0.01), whereas there was no difference of F1 IgG titer between immunized guinea pigs and rabbits (q = 0.06, P = 0.8098). The immunized mice, guinea pigs and rabbits with subunit vaccine provided 100% (10/10), 86% (12/14) and 100% (5/5) protection against 10(6) CFU Y. pestis of challenge, respectively. The immunized mice, guinea pigs and rabbits with EV76 vaccine gave 100% (6/6), 93% (13/14) and 100% (6/6) protection against 10(6) CFU Y. pestis of challenge respectively.

CONCLUSIONBALB/c mice is the best small animal model for valuation of protective efficacy of plague subunit vaccine. The guinea pigs showed a high individual variation for this purpose. The rabbits can be used as an alternative model for evaluating plague subunit vaccine.

Animals ; Antibodies, Bacterial ; blood ; Dose-Response Relationship, Immunologic ; Female ; Guinea Pigs ; Immunization ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Models, Animal ; Plague ; prevention & control ; Plague Vaccine ; immunology ; Rabbits ; Vaccines, Subunit ; immunology

OBJECTIVETo describe the epidemiology of neural tube defects (NTDs) in high- and low-prevalence areas of China.

METHODSBirth defects surveillance data, collected from 1992 through 1994 was analyzed. These data were collected as part of the Sino-American cooperative project on NTDs prevention. We classified NTDs as anencephaly, encephalocele, high-level and low-level spina bifida (SB) according to location of the lesion (high vs low) and whether the defect was isolated or occurred in association with other birth defects. Rates were compared in the high-prevalence (North) region and the low-prevalence (South) region, after adjusted for classification, urban and rural, season and sex, and calculated the adjusted rate of NTDs.

RESULTSAmong seven hundred and eighty-four NTDs cases in 326 874 recorded births (include in livebirth, stillbirth and fetal death with a gestational age of at least 20 weeks), the overall NTDs prevalence in the North was 5.57/1,000 births, and in the South was 0.88/1 000. There were also significant differences in the prevalence of anencephaly, encephalocele, high-level and low-level SB between North (0.97, 0.49, 2.75 and 1.11/1,000 birth) and South (0.36, 0.15, 0.21 and 0.14/1,000 birth) (P < 0.01), with adjusted prevalences in the North 3 - 7 times higher than those in the South. There were significant difference between urban (2.04) and rural areas (6.57/1,000 birth) in the North (P < 0.01), urban (0.52) and rural areas (0.95/1,000 birth) in the South (P < 0.05). Adjusted prevalence rates in the rural were 3 - 4 times higher than those of urban in the North and 1.6 - 1.9 times higher than in the South; The seasonal rate of high-level SB increased between September and November in the North (3.44/1,000 birth), while the seasonal rate of anencephaly decreased between September and November (0.18/1,000 birth) in the South. However there were no seasonal changes in other classified NTDs both in the South and North.

CONCLUSIONSThe birth prevalence of NTDs in the North of China was the highest in the world. There were significant differences between the North and the South, urban and rural. There was seasonal change in high-level SB in the North, which was in accordance to the phenotype of NTDs. It was suggested that there might exist etiological heterogeneity among anecephalus, low- and high-level SB.

China ; epidemiology ; Female ; Humans ; Incidence ; Male ; Neural Tube Defects ; epidemiology ; Seasons

Acute upper respiratory tract infection is the most common infectious disease in children's respiratory system. The pathogen to the main virus, can account for more than 90% of the primary upper respiratory tract infectio. However, there is no specific anti-viral drugs specifically for the disease, in addition to the existence of excessive, widespread use or even abuse of antibiotics.Long-term clinical practice has confirmed that Chinese medicine is safe and effective in treating acute upper respiratory tract infection in children. The author reviews the literatures of multiple databases, and analyzes the advantages of Chinese patent medicine in the treatment of acute upper respiratory tract infection in children from the perspective of clinical research and experimental basic research. It also puts forward the existing problems and possible research directions of Chinese patent medicine in the treatment of acute upper respiratory tract infection in children.

The nanosuspension of quercetin (QT-NS) was prepared by a miniaturized milling method, and the process was optimized by Box-Behnken response surface method. Then the accumulative release rate of QT-NS in vitro was determined. The results showed that the optimal process parameters were as follows: ZrO2 4.5 mL, milling speed 690 r•min⁻¹ and milling time 1.5 h; the particle size of QT-NS was (169±5) nm, polydispersity index of 0.204±0.006 and stability index of 0.827±0.014, respectively. There was a little deviation between the theoretically predicted value and the measured value, indicating that this model had a good prediction effect. The accumulative release rate in vitro of QT-NS in 120 min was significantly higher than that of the raw drug and physical mixture. This simple low-cost miniaturization approach could prepare QT-NS successfully, and could provide reference for the formulation of the nanosuspension.