Epidemiology and strain variation of Cryptosporidium parvum.
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Animals↗
Biomedical subjects
L Xiao
Publications and source records attributed to L Xiao.
Molecular characterization of a Cryptosporidium isolate from a black bear.
To further validate the observation of the existence of host-adapted strains of Cryptosporidium parvum, we genetically characterized an isolate of Cryptosporidium parasite from a black bear. Sequence analysis of the ribosomal RNA small subunit and the 70-kDa heat shock protein (HSP70) showed that this parasite represents a new genotype of C. parvum and is related to the C. parvum dog genotype. This finding is helpful for clarifying Cryptosporidium taxonomy.
Animals↗
Detection of the Cryptosporidium parvum "human" genotype in a dugong (Dugong dugon).
The Cryptosporidium "human" genotype was identified in a paraffin-embedded tissue section from a dugong (Dugong dugon) by 2 independent laboratories. DNA sequencing and polymerase chain reaction/restriction fragment length polymorphism analysis of the 18S ribosomal RNA gene and the acetyl CoA synthethase gene clearly identified the genotype as that of the Cryptosporidium variant that infects humans. This is the first report of the human Cryptosporidium genotype in a nonprimate host.
Acetate-CoA Ligase↗
Expression of proinflammatory cytokines in four regions of the brain in Macaque mulatta (rhesus) monkeys infected with Plasmodium coatneyi.
We have characterized brain cytokine expression profiles in the Plasmodium coatneyi/rhesus (Macaque mulatta) malaria model. Eight rhesus monkeys were included in the study; four were infected with P. coatneyi, and four were used as uninfected controls. All inoculated animals became infected. Eleven days after parasite inoculation, the rhesus monkeys were killed and tissue samples from 4 regions of the brain (cortex and white matter of the cerebrum, cerebellum, and midbrain) were collected for quantitation of mRNA expression of cytokines, adhesion molecules, and inducible nitric oxide synthetase (iNOS) by reverse transcriptase-polymerase chain reaction (RT-PCR). The expression levels of tumor necrosis actor-alpha (TNF-alpha), gamma interferon (IFN-gamma), interleukin-1-beta (IL-1beta), intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synethetase (iNOS) were highest in the cerebellum of infected animals, correlating well with pathologic observations of sequestration of parasitized erythrocytes in this region of the brain. Infected animals also had higher TNF-alpha expression levels in the cortex and IL-1beta expression levels in the cortex, white matter, and midbrain. Thus, the expression of pro-inflammatory and T helper-1 (TH-1) cytokines, adhesion molecules, and iNOS appears to predominate in the cerebellum of infected rhesus monkeys.
Animals↗
[Perioperative changes of plasma ET-1 in patients undergoing coronary artery bypass grafting and the effect of nitroglycerin].
OBJECTIVE: To observe the dynamic changes of the plasma ET-1 and the effect of low dose nitroglycerin in patients with coronary artery bypass surgery. METHODS: 40 patients with coronary artery bypass surgery were divided into group A and B. Group B received intravenous nitroglycerin 1 microg x kg(-1) x min(-1) perioperatively. We used RIA to assay the plasma ET-1 level. All the hemodynamic parameters were recorded by the Swan-Ganz catheter. RESULTS: The preoperative plasma ET-1 level in patients with coronary artery disease was significantly higher than the normal level. Five minutes after cardiopulmonary bypass in these patients the plasma ET-1 level was increased significantly until 6 to 8 hours after operation. The increased plasma ET-1 level in group B was less than in group A. There was a positive correlation between the plasma ET-1 level and the mean pulmonary pressure in group A 2 and 8 hours after operation. CONCLUSION: In patients undergoing coronary artery bypass surgery, the increased plasma ET-1 level may be partly due to the influence of cardiopulmonary bypass. Low dose of nitroglycerin is beneficial to these patients.
Coronary Artery Bypass↗
[Antitumor activity of the lysates prepared from anti-CD3 antibody activated killer cells].
This study was directed at the antitumor activity of the lysates prepared from CD3McAb activated killer cells. We separated the peripheral blood monocytes(PBMC) from normal adults. The PBMC were induced by monoclonal antibody specific for CD3(CD3McAb) and activated by rIL-2. The CD3McAb-activated killer cells (CD3AK) were smashed by ultrasonic wave, along with frozen and thawed three times, then the lysates were obtained by centrifugation. The lysates were tested for antitumor activity in vivo and in vitro. The results revealed that the inhibition rate of the lysates that acted on mice solid tumor hepatoma 22(H22) was 68.20% and the killing activity of the lysates on K562 and Raji were 83.32%, and 66.83% respectively. The results of this experiment suggested that the lysates prepared from CD3McAb-activated killer cells is one of probable agents that might apply to biotherapy for tumors.
Animals↗
[A study of the immune in formation of calcium bilirubinate gallstones in different rabbit models--the changes of the immunoglobulins in serum and bile and the immunoglobulins forming cells in the gallbladder mucoderm].
The changes of Ig-forming cells in the gallbladder mucoderm and the immunoglobulins in serum and bile were studied in the rabbit models. One hundred rabbits were randomly divided into the control group (Con, n = 10), simple biliary obstruction group (BO, n = 45) and biliary obstruction and infection group (BOI, n = 45). The results showed that the concentrations of serum immunoglobulin A (IgA) in BO and BOI groups increased remarkably in all phases (P < 0.001), The concentrations of serum IgG in both groups increased with the formation of gallstones. The IgA and IgG contents of bile samples in BO and BOI groups with negative bacterial culture were much higher than those of control group (P < 0.05), but the Ig content of bile with positive culture was slightly lower than that of the control group. Only a few Ig-forming cells were found in the gallbladder mucoderm of normal rabbits. The counts of Ig-forming cells in the mucoderm in BO group remained unchanged, but increased much higher in BOI group (P < 0.001), especially in IgG formation. This experiment demonstrates the immunoglobulins of serum and bile change significantly during the formation of gallstones. The Ig content of bile has a relationship with bacterial infection. IgA plays an important role in gallstone formation. The gallbladder of rabbit may be an important place of Ig-formation. The quantity of Ig forming cells in biliary tract may have a close relationship with the gallstone formation.
Animals↗
[Changes of lipoprotein lipase and hepatic lipase and their significance in gallstone formation in rabbit model].
This experiment was made to investigate the changes of lipoprotein lipase(LPL) and hepatic lipase (HL) activity and their effects on gallstone formation in rabbit model in which the stones were induced by high cholesterol diet. Activities of plasma LPL and HL were determined; other data including concentration of plasma lipoprotein cholesterol, concentration of bile cholesterol and bile acids were also obtained. The results showed that with the rabbits continuously fed on high cholesterol diet, LPL activity heightened markedly (P < 0.05), and HL activity increased gradually (3 and 4 weeks groups vs control group, P < 0.05). The changes of concentration of plasma VLDL-C and LDL-C were the same as that of LPL activity, but the concentration of plasma HDL-C, HDL2-C, HDL3-C and bile acids showed no significant changes (P > 0.05). These results suggest that the heightened activities of LPL and HL might make the liver take up more cholesterol, secrete it into the bile duct and hence accelerate gallstone formation.
Animals↗
[Relationship of p53 gene mutation with pathological characteristics and prognosis of thyroid carcinoma].
This study was directed to the role of p53 gene in the carcinogenesis of thyroid carcinomas and to the correlation between p53 gene and the clinicopathological characteristics of the cancer. Single-stranded conformation polymorphism of PCR was used in detecting p53 gene point mutations in exons 7, 8. The result showed that ten of thirty-one thyroid carcinomas had mutations in exons 7 and 8 (32.3%). The frequency of p53 gene mutations was significantly higher in relapse group than in no relapse group (P < 0.01). No statistically significant differences in p53 mutation were found relating to metastasis, histological type and differentiation (P > 0.05). These data suggest that the mutation of p53 gene may play an important role in thyroid carcinoma and the mutations of p53 gene be associated with the prognosis of thyroid carcinoma.
Adenocarcinoma, Follicular↗
[Study on lipids and other volatile constituents in Pheretima aspergillum].
To study chemical constituents in Pheretima aspergillum, three kinds of fractions were obtained from this drug by soxhlet extraction with different solvents, and the chemical structures of thirty-six volatile components were identified by means of GC-MS. The eleven in ether fraction were all lipids and the relative content of non-saturated fatty acid was the highest(27.70%) such as oleic acid, linoleic acid, arachidonic acid and eicosatrienoic acid; There were eight lipids in acetone fraction (35.75%), which included one kind of nonsaturated fatty acid (linoleic acid); There were thirteen lipids in ethanol fraction (72.09%), which non-saturated fatty acid has never been detected. This study has determined the lipid composition in Pheretima aspergillum, especially non-saturated fatty acid, and afforded chemical base to cardio-cerebro-vascular therapy.
Animals↗
[Impact of glutamine of gut permeability and clinical prognosis on the aging patients undergoing gastric-intestinal operation].
OBJECTIVE: To evaluate the impact of parenteral nutrition supplemented glutamine on aging patients undergoing gastric-intestinal operation. METHODS: 30 patients above 60 years old undergoing gastric-intestinal operation, a randomized double-blind protocol was designed, divided into two groups, received impact isocaloric parenteral nutrition. The study group received alanyl-glutamine [0.5 g/(kg.d)]. To observe plasma amino acids profile, nitrogen balance, intestinal permeability and clinical prognosis, examine clinical chemistry variables and observe the adverse reactions in order to find out its safety. RESULTS: The patients in both groups were comparable prior to the operation. The plasma glutamine level of study group is higher than the control group, it's cumulative nitrogen balance values were prior to the control group, L/M ratio was lower than the control group. The complications related to infection was observed more in the control group. No adverse reaction was observed in both groups. CONCLUSIONS: Ala-Gln-supplemented PN improved nitrogen balance and maintained intestinal permeability, reduced complications.
Aged↗
[Pharmacological action and health protection function of Pheretima].
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Amino Acids, Essential↗
[Application of UV spectrophotometry in the detection of magnetization effect].
Compared the UV absorption spectra of some magnetized samples with them of unmagnetized samples(the pure solvents and unmagnetized solutions as the reference substances separately), we found the wavelength of absorption didn't change, but strength of absorption of all magnetized compounds changed. When unmagnetized solutions is selected as reference substances, there may be a peak of magnetic effect in UV absorption spectra. Furthermore, the different magnetization time made the absorbance change in varying degrees. This research will play an important role for the study of possible mechanism of magnetic field effect on chemical reaction.
Magnetics↗
Partial resistance to infection by R5X4 primary HIV type 1 isolates in an exposed-uninfected individual homozygous for CCR5 32-base pair deletion.
It is known that certain individuals remain persistently seronegative despite repeated exposure to HIV-1. Studies have shown that some exposed uninfected (EU) individuals who are homozygous for a 32-bp deletion in the CCR5 gene are resistant to infection with non-syncytium-inducing (R5) viruses. In the present investigation, we provide evidence that a highly exposed-uninfected individual with the CCR5 32-bp deletion (EUdelta32-1) also has partial resistance to syncytium-inducing (R5X4) HIV-1 viruses, when compared with unexposed-uninfected individuals with (UUdelta32-1 and UUdelta32-2) and without (UU-1 and UU-2) the 32-bp deletion. The partial resistance of EU cells was due neither to altered coreceptor expression, nor to specific mutation or deletion in the coding region of chemokine coreceptors CXCR4 and CCR3. While SDF-1, the ligand for CXCR4, blocked entry of R5X4 viruses to a similar extent in EUdelta32 and UUdelta32, there was a differential production of soluble factors by EUdelta32. Both CD4+ and CD8+ cells from EUdelta32-1 produced soluble factors that efficiently suppressed infection by HIV-1 R5X4 viruses when compared with supernatant from UUdelta32. These data provide evidence that additional soluble factors are involved in resistance to infection with R5X4 viruses.
CD4-Positive T-Lymphocytes↗
Prolonged expression of IFNgamma induced by protective blood-stage immunization against Plasmodium yoelii malaria.
Mice vaccinated with whole blood-stage antigens of Plasmodium yoelii develop protective, antibody-mediated immune responses to homologous challenge infection. In this model the level of protection induced by whole parasite antigen vaccination is dependent on antibody isotype, which can be influenced by adjuvant formulations. In this study the ability adjuvant formulations to affect cytokine production and protection against P. yoelii blood-stage infection was investigated. Survival of mice in groups vaccinated with P. yoelii antigens in an aqueous mix of copolymer P1005 + RaLPS was 100%. Mice vaccinated with either P. yoelii antigens alone or combined with a water-in-oil emulsion of copolymer P1005 + RaLPS demonstrated 83 or 50% survival, respectively. The fully protective aqueous vaccine group produced higher levels of interferon gamma (IFNgamma) and interleukin 4 (IL-4) than the water-in-oil vaccine group following a live parasite challenge infection. Furthermore, mice vaccinated with the aqueous vaccine displayed prolonged IFNgamma and IL-4 response as compared to mice that received the same antigens without adjuvants. These data support the hypothesis that both the Th1 cytokine IFNgamma, and the Th2 cytokine IL-4 are modulated by the vaccine vehicle and adjuvant used for vaccination, thus possibly affecting expression of protective immune responses. However, it is the long-lasting IFNgamma response following blood-stage P. yoelii parasite challenge that is associated with enhanced survival.
Adjuvants, Immunologic↗
Electrostatic contributions to the stability of hyperthermophilic proteins.
Electrostatic contributions to the folding free energy of several hyperthermophilic proteins and their mesophilic homologs are calculated. In all the cases studied, electrostatic interactions are more favorable in the hyperthermophilic proteins. The electrostatic free energy is found not to be correlated with the number of ionizable amino acid residues, ion pairs or ion pair networks in a protein, but rather depends on the location of these groups within the protein structure. Moreover, due to the large free energy cost associated with burying charged groups, buried ion pairs are found to be destabilizing unless they undergo favorable interactions with additional polar groups, including other ion pairs. The latter case involves the formation of stabilizing ion pair networks as is observed in a number of proteins. Ion pairs located on the protein surface also provide stabilizing interactions in a number of cases. Taken together, our results suggest that many hyperthermophilic proteins enhance electrostatic interactions through the optimum placement of charged amino acid residues within the protein structure, although different design strategies are used in different cases. Other physical mechanisms are also likely to contribute, however optimizing electrostatic interactions offers a simple means of enhancing stability without disrupting the core residues characteristic of different protein families.
Amino Acid Sequence↗
Variation in Cryptosporidium: towards a taxonomic revision of the genus.
Cryptosporidium is an important cause of enteric disease in humans and other animals. Limitations associated with conventional diagnostic methods for cryptosporidiosis based on morphological features, coupled with the difficulty of characterising parasites isolated in the laboratory, have restricted our ability to clearly identify species. The application of sensitive molecular approaches has obviated the necessity for laboratory amplification. Such studies have found considerable evidence of genetic heterogeneity among isolates of Cryptosporidium from different species of vertebrate, and there is now mounting evidence suggesting that a series of host-adapted genotypes/strains/species of the parasite exist. In this article, studies on the molecular characterisation of Cryptosporidium during the last 5 years are reviewed and put into perspective with the past and present taxonomy of the genus. The predictive value of achieving a sound taxonomy for the genus Cryptosporidium with respect to understanding its epidemiology and transmission and controlling outbreaks of the disease is also discussed.
Animals↗
Sequence comparison of the L2 and S10 genes of bluetongue viruses from the United States and the People's Republic of China.
Bluetongue virus (BTV) infection of ruminants is endemic throughout much of the US and China. The S10 and a portion of the L2 gene segments of Chinese prototype strains of BTV serotypes 1, 2, 3, 4, 12, 15, and 16 were sequenced and compared to the same genes of prototype and field strains of BTV from the US. Phylogenetic analysis of the S10 gene segregated the Chinese viruses into a monophyletic group distinct from the US viruses, whereas similar analysis of the L2 gene segregated strains of BTV according to serotype, regardless of geographic origin.
Bluetongue virus↗