Biomedical subjects

Bin Lu

Publications and source records attributed to Bin Lu.

At least 55 records · Page 3Linked to original sources

PubMed2005

Shedaoenase, a novel fibrinogenase from the venom of Agkistrodon shedaoenthesis Zhao.

Shedaoenase, a serine protease, was isolated from the venom of Agkistrodon shedaoenthesis Zhao with an apparent molecular mass of 36 kDa. It was purified by affinity chromatography on arginine Sepharose 4B column and anion exchange on Mono Q fast protein liquid chromatography. Shedaoenase preferentially cleaved the Aalpha-chain of human fibrinogen and slowly digested the Bbeta-chain. It also showed arginyl esterase activity using Nalpha-benzoyl-L-arginine ethyl ester as a substrate, and some synthetic chromogentic substrates, such as Chromozym PL, S-2266, and S-2160, could also be hydrolyzed. The enzyme activity of shedaoenase could be completely inhibited by phenylmethylsulphonylfluoride and could be little inhibited by the chelating reagent EDTA. The N-terminal sequence of shedaoenase was determined, and its full-length cDNA encoding a protein of 238 amino acid residues was cloned by reverse transcription-polymerase chain reaction from the total mRNA extracted from the snake venom gland. The deduced primary sequence of shedaoenase shares significant homology with other snake venom serine proteases.

Agkistrodon↗

PubMed2005

Improvement of influenza A/Fujian/411/02 (H3N2) virus growth in embryonated chicken eggs by balancing the hemagglutinin and neuraminidase activities, using reverse genetics.

The H3N2 influenza A/Fujian/411/02-like virus strains that circulated during the 2003-2004 influenza season caused influenza epidemics. Most of the A/Fujian/411/02 virus lineages did not replicate well in embryonated chicken eggs and had to be isolated originally by cell culture. The molecular basis for the poor replication of A/Fujian/411/02 virus was examined in this study by the reverse genetics technology. Two antigenically related strains that replicated well in embryonated chicken eggs, A/Sendai-H/F4962/02 and A/Wyoming/03/03, were compared with the prototype A/Fujian/411/02 virus. A/Sendai differed from A/Fujian by three amino acids in the neuraminidase (NA), whereas A/Wyoming differed from A/Fujian by five amino acids in the hemagglutinin (HA). The HA and NA segments of these three viruses were reassorted with cold-adapted A/Ann Arbor/6/60, the master donor virus for the live attenuated type A influenza vaccines (FluMist). The HA and NA residues differed between these three H3N2 viruses evaluated for their impact on virus replication in MDCK cells and in embryonated chicken eggs. It was determined that replication of A/Fujian/411/02 in eggs could be improved by either changing minimum of two HA residues (G186V and V226I) to increase the HA receptor-binding ability or by changing a minimum of two NA residues (E119Q and Q136K) to lower the NA enzymatic activity. Alternatively, recombinant A/Fujian/411/02 virus could be adapted to grow in eggs by two amino acid substitutions in the HA molecule (H183L and V226A), which also resulted in the increased HA receptor-binding activity. Thus, the balance between the HA and NA activities is critical for influenza virus replication in a different host system. The HA or NA changes that increased A/Fujian/411/02 virus replication in embryonated chicken eggs were found to have no significant impact on antigenicity of these recombinant viruses. This study demonstrated that the reverse genetics technology could be used to improve the manufacture of the influenza vaccines.

Adaptation, Physiological↗

PubMed2005

Grafting of ARPE-19 and Schwann cells to the subretinal space in RCS rats.

PURPOSE: To study the distribution of the human retinal pigment epithelium (hRPE) cell line ARPE-19 and human Schwann (hSC) cells grafted to the subretinal space of the Royal College of Surgeon (RCS) rat and the relation of graft cell distribution to photoreceptor rescue. METHODS: Cell suspensions of both donor types were injected into the subretinal space of 3-week-old dystrophic RCS rats through a transscleral approach, human fibroblast and medium were used as control grafts. All animals were maintained on oral cyclosporine. At 1, 2, 4, 6, 15, 28, and 36 weeks after grafting, animals were killed. Human cell-specific markers were used to localize donor cells. RESULTS: Both donor cell types, as revealed by antibodies survived for a substantial time. Their distribution was very different: hRPE cells formed a large clump early on and, with time, spread along the host RPE in a layer one to two cells deep, whereas hSCs formed many smaller clumps, mainly in the subretinal space. Both cells rescued photoreceptors beyond the area of donor cell distribution. The number of surviving cells declined with time. CONCLUSIONS: Both hRPE and hSC grafts can survive and rescue photoreceptors for a substantial time after grafting. The number of both donor cell types declined with time, which could be an immune-related problem and/or due to other factors intrinsic to the host RCS retina. The fact that rescue occurred beyond the area of donor cell distribution suggests that diffusible factors are involved, raising the possibility that the two cell types function in a similar manner to rescue photoreceptors.

Animals↗

PubMed2005

[Immunohistochemical study on expression of iNOS and eNOS during skin incised wound healing in mice].

OBJECTIVE: To investigate the expressions of iNOS and eNOS during skin incised wound healing and the applicability of time-dependent expressions of iNOS and eNOS to timing of wound. METHODS: An incised wound was made in the dorsal skin of mouse. By using S-P method, the expression of iNOS and eNOS were studied in cutaneous incised wound as well as normal skin in control mice. RESULTS: iNOS and eNOS expressed in epidermis, hair follicle, sebaceous gland, and the eNOS were also found in vascular endothelium in control group. Three hours after injuryed, the expression of iNOS and eNOS were detected in polymorphonuclear cells (PMNs) in the wound and peripheral region. From 6h to 24h of wound interval, the expression of NOS isoforms were identified in a large number of infiltrating PMNs and part of mononuclear cells (MNCs), afterwards the MNCs and fibroblastic cells (FBCs) accounted for the most part of the iNOS and eNOS positive cells. In addition, during wound healing, the expressions of iNOS and eNOS were noticed in different level in vascular epithelial cells, especially neonatal capillary vessel in granulation tissue. CONCLUSION: The results suggest that iNOS and eNOS express in polymorphonuclear cells, macrophages and fibroblasts during healing process of skin incised wound in mice. Furthermore, iNOS and eNOS may play pivotal roles in all the events relating to wound healing, and the time-dependent expressions of iNOS and eNOS may possibly be used as new markers for the wound age determination.

Animals↗

PubMed2005

[The effects of polygoni multiflori total glycosides on the experimentally atherosclerotic formation in apoE-deficient mice].

OBJECTIVE: To study the effect of polygoni multiflori total glycosides (PMTG) on the expressions of ICAM-1 and VCAM-1 in the apoE-deficienct (ApoE-/-)mice with experimental atherosclerosis (AS) and underlying mechanism. METHOD: Thirty-two female apoE-deficienct mice were randomized into four groups: high dose PMTG group (150 mg x kg(-1) x d(-1)), low dose PMTG group (25 mg x kg(-1) x d(-1)), atorvastatin positive control group (5 mg x kg(-1) x d(-1)) and model group. At the end of the tenth week of treatment, all mice were killed. The serum levels of total cholesterol (TC), triglyceride(TG), high-density lipoprotein-cholesterol (HDL-C) were measured by enzyme dynamics method. Light microscopy were adopted to assess the degree of atherosclerotic plaque of aortic wall and image analysis was performed with computer. The expressions of ICAM-1 and VCAM-1 were studied by SABC imunohistochemistry. RESULT: In comparison with the model group, (1) PMTG reduced the levels of serum TC and TG significantly (P < 0.01), but elevated HDL level obviously (P < 0.01) . (2) PMTG increased the levels of serum NO and the anti-oxidation capacities significantly (P < 0.05 and P < 0.01), but reduced the levels of serum MDA markedly (P < 0.01). (3) PMTG reduced also the extent of atherosclerotic plaque of aorta areas were (P < 0.05). (4) PMTG deregulated the expressions of ICAM-1 and VCAM-1 in aortic wall. CONCLUSION: PMTG could inhibit the occurrence and development of atherosclerotic lesions by the regulating lipid metabolism and anti-oxidation and deregulating the of expressiona of ICAM-1 and VCAM-1 in AopE-/- mice in aortic wall.

Animals↗

PubMed2004

Increased c-fos-like immunoreactivity in the superior colliculus and lateral geniculate nucleus of the rd mouse.

In most subcortical visual centers in normal mice maintained for a period in the dark, very few neurons express fos-like immunoreactivity (FLI), most likely reflecting c-fos expression, but if an animal is exposed to a flashing light, there is transient increase in the number of FLI-expressing cells. In dark-maintained retinal degeneration (rd) mice, with an inherited photoreceptor defect, numbers of FLI-positive cells, identified immunohistochemically, are anomalously elevated in the superior colliculus (SC) and lateral geniculate nucleus (LGN). Eye removal largely prevents the elevated counts. The difference in number of FLI-positive cells in the SC of rd mice and nondystrophic controls is highly significant (p<0.001). Because we have previously found a similar phenomenon in Royal College of Surgeons (RCS) rats, in which photoreceptor loss is caused by a retinal pigment cell defect, it argues for an effect related to photoreceptor loss rather than its cause.

Animals↗

PubMed2004

Polymorphisms in the DNA repair gene XPD and susceptibility to esophageal squamous cell carcinoma.

Polymorphisms of the nucleotide excision repair gene XPD are candidates for influencing cancer susceptibility. To determine the effect of XPD genetic polymorphisms on the risk of esophageal squamous cell carcinoma (ESCC) and its interaction with carcinogen exposure, XPD polymorphisms at codon 312 (Asp-->Asn) and codon 751 (Lys-->Gln) were determined in 135 ESCC patients and 152 normal controls. Polymorphism at codon 312 made no contribution to genetic risk for ESCC. Our results showed that there was a significant difference between frequencies for XPD 751 Gln/Gln genotype in ESCC patients (8.9%) and normal cases (1.3%), and that Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio [OR] = 6.71; 95% confidence interval [CI]: 1.90-23.73). The results of the logistic regression model showed that XPD 751 Gln/Gln genotype and drinking were candidates for influencing the risk of ESCC. Among smokers, the risk of ESCC in XPD 751 Gln/Gln genotype increased 8-fold than that XPD 751 Lys/Lys genotype (OR = 8.42, 95% CI: 1.02-69.58). The results indicated that XPD 751 Gln/Gln genotype may be contributing factors in the risk of ESCC and may modify risk attributable to environmental exposures.

Aged↗

PubMed2004

Baseline heart rate-adjusted electrocardiographic triggering for coronary artery electron-beam CT angiography.

Conventional electrocardiographic (ECG) triggering (group 1, 53 patients) was compared with baseline heart rate-adjusted ECG triggering (group 2, 54 patients) for coronary artery electron-beam computed tomographic (CT) angiography. CT angiographic data sets were compared blindly with conventional angiograms according to segment. Nonassessability of coronary artery segments was reduced from 35% in group 1 to 13% in group 2 (P < .001). More motion-free coronary artery images were obtained in group 2 than in group 1, especially in the right coronary artery (95% vs 67%, P < .001). Overall sensitivity and specificity for luminal stenosis (> or =50%) were 69% and 82% (group 1) and 76% and 92% (group 2) (P > .05 and P < .001, respectively). Baseline heart rate-adjusted ECG triggering improves image quality at coronary artery CT angiography for detection of coronary artery disease.

Adult↗

PubMed2004

Abnormal c-fos-like immunoreactivity in the superior colliculus and other subcortical visual centers of pigmented Royal College of Surgeons rats.

Neurons in the central nervous system often show a transient up-regulation of expression of the immediate early gene c-fos when presented with precise novel stimuli. In normal rats, neurons in most subcortical visual centers show low levels of fos-like immunoreactivity (FLI) expression, but there is a substantial and transient increase in FLI expression if the animal is exposed to a flashing light. This is especially evident in the superior colliculus (SC). We have examined here FLI expression in the subcortical visual centers of the Royal College of Surgeons rat, focusing specifically on the SC. In this animal, as a result of a genetic defect, there is early loss of rod photoreceptors over the first few months of life, along with slower disappearance of cones. Although light stimulation showed that FLI expression was very similar to that seen in normal rats, the basal levels of FLI expression under dark-maintained conditions were much higher than normal, even exceeding the levels seen after visual stimulation. In the SC, the elevation of FLI expression was already evident by 6 weeks of age and reached a plateau by 17 weeks. Other subcortical visual centers also showed elevated basal levels of FLI expression, although in general the increases were less dramatic than the increase in the SC. The elevated FLI expression in dark-maintained condition seen in the SC was abolished by contralateral optic nerve section. It was also severely diminished by subretinal cell transplantation at 3 weeks of age with the objective of limiting photoreceptor loss over part of the retina. These results suggest that the elevated basal FLI expression is a retina-driven event. Although it correlates with the loss of rod photoreceptors, it is unlikely to reflect reduced photoreceptor drive but rather some form of bursting activity generated in the inner retina, as a result of circuit reorganization or receptor up-regulation.

Animals↗

PubMed2004

Insulin expression in livers of diabetic mice mediated by hydrodynamics-based administration.

AIM: Transfer and expression of insulin gene in vivo are an alternative strategy to improve glycemic control in type 1 diabetes. Hydrodynamics-based procedure has been proved to be very efficient to transfer naked DNA to mouse livers. The basal hepatic insulin production mediated by this rapid tail vein injection was studied to determine its effect on the resumption of glycemic control in type 1 diabetic mice. METHODS: Engineered insulin cDNA was inserted into plasmid vectors under a CMV promoter, and transferred into STZ induced diabetic mice by hydrodynamic procedure. Glucose levels, body weight of treated mice, insulin levels, immunohistology of the liver, and quantity of insulin mRNA in the liver were assayed to identify the improvement of hyperglycemic complication after plasmid administration. Sleeping Beauty, a transposon system, was also used to prolong the insulin expression in the liver. RESULTS: After plasmid administration, Plasma insulin was significantly increased in the diabetic mice and the livers were insulin-positive by immunostaining. At the same time the hyperglycemic complication was improved. The blood glucose levels of mice were reduced to normal. Glucose tolerance of the treated diabetic mice was improved. Body weight loss was also ameliorated. The rapid tail vein injection did not cause any fatal result. CONCLUSION: Our results suggested that insulin gene could be efficiently transferred into the livers of diabetic mice via rapid tail vein injection and it resulted in high level of insulin expression. The basal hepatic insulin production mediated by hydrodynamics-based administration improved the glycemic control in type 1 diabetes dramatically and ameliorated diabetic syndromes. Hydrodynamics-based administration offers a simple and efficient way in the study of gene therapy for type 1 diabetes.

Animals↗

PubMed2004

DNA and RNA binding by the mitochondrial lon protease is regulated by nucleotide and protein substrate.

The ATP-dependent Lon protease belongs to a unique group of proteases that bind DNA. Eukaryotic Lon is a homo-oligomeric ring-shaped complex localized to the mitochondrial matrix. In vitro, human Lon binds specifically to a single-stranded GT-rich DNA sequence overlapping the light strand promoter of human mitochondrial DNA (mtDNA). We demonstrate that Lon binds GT-rich DNA sequences found throughout the heavy strand of mtDNA and that it also interacts specifically with GU-rich RNA. ATP inhibits the binding of Lon to DNA or RNA, whereas the presence of protein substrate increases the DNA binding affinity of Lon 3.5-fold. We show that nucleotide inhibition and protein substrate stimulation coordinately regulate DNA binding. In contrast to the wild type enzyme, a Lon mutant lacking both ATPase and protease activity binds nucleic acid; however, protein substrate fails to stimulate binding. These results suggest that conformational changes in the Lon holoenzyme induced by nucleotide and protein substrate modulate the binding affinity for single-stranded mtDNA and RNA in vivo. Co-immunoprecipitation experiments show that Lon interacts with mtDNA polymerase gamma and the Twinkle helicase, which are components of mitochondrial nucleoids. Taken together, these results suggest that Lon participates directly in the metabolism of mtDNA.

ATP-Dependent Proteases↗

PubMed2004

Methodology for improved detection of coronary stenoses with computed tomographic angiography.

BACKGROUND: Noninvasive angiography is a promising technique for visualization of the coronary lumen; however, current methodologies lead to limited accuracy. We assessed the accuracy of electron beam computed tomographic angiography (EBA) for detection of coronary stenoses, using improved triggering techniques and thinner slice collimation. METHODS: Eighty-six patients with suspected coronary disease were studied with EBA and conventional invasive coronary angiography. Electrocardiographic triggering was performed at a fixed time in end systole to reduce cardiac motion. Thin (1.5 mm) slices were obtained with 1.5 mm table incrementation. In axial (2-dimensional) EBA images and 3-dimensional reconstructions, all coronary arteries and side branches with a diameter of >or=1.5 mm were assessed for the presence of stenoses with >50% diameter reduction. Both EBA and invasive angiographic images were assessed in a blinded manner. RESULTS: In comparison to invasive coronary angiography, EBA correctly classified 49 of 53 patients (92%) as having at least 1 coronary stenosis. Overall, 103 stenoses with >50% diameter reduction were present, and 93 of these lesions were correctly detected by EBA (sensitivity 90%, specificity 93%, positive predictive value 84%, and negative predictive value 96%). Only 5% of vessels could not be assessed, predominantly due to significant calcification. CONCLUSIONS: Thinner slice collimation and end-systolic electrocardiographic triggering improves accuracy and assessment of coronary EBA for the detection of obstructive coronary artery disease, making this study clinically useful in the evaluation of obstructive coronary artery disease.

Coronary Angiography↗

PubMed2004

DNA repair gene XRCC1 polymorphisms, smoking, and esophageal cancer risk.

To investigate the effect of X-ray repair cross complementing 1 (XRCC1) genetic polymorphisms on esophageal cancer risk, we determined XRCC1 polymorphisms at codon 194 (Arg --> Trp) and codon 399 (Arg --> Gln) in 135 patients with esophageal squamous cell carcinoma (ESCC) and 152 normal controls from hospitals. Although polymorphism at codon 194 was not associated with risk for ESCC, we found that the frequency of XRCC1 399 Gln/Gln genotype in ESCC patients (14.1%) was significantly higher than that in normal controls (3.3%), and that XRCC1 399 Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio (OR) = 5.15, 95% confidence interval (CI): 2.42-0.93). In addition, we found that the risk for smoker increased 4.2-fold than non-smokers in the 399 Gln/Gln genotype (OR = 4.20, 95% CI: 2.37-7.44). These results suggest that XRCC1 399 Gln/Gln genotype may contribute to the risk of ESCC and modify risk associated with smoking.

Age Distribution↗

PubMed2004

Inhibiting progression of coronary calcification using Aged Garlic Extract in patients receiving statin therapy: a preliminary study.

BACKGROUND: Aged Garlic Extract (AGE) reduces multiple cardiovascular risk factors, including blood pressure, cholesterol, platelet aggregation and adhesion, while stimulating nitric oxide generation in endothelial cells. However, no study has evaluated the ability of AGE to inhibit vascular calcification, a marker of plaque formation in human coronary arteries. OBJECTIVE: To assess the efficacy of Aged Garlic Extract (AGE) on changing the rate of atherosclerosis progression as compared to placebo. DESIGN: A placebo-controlled, double-blind, randomized pilot study to determine whether the atherosclerotic plaque burden detected by electron beam tomography (EBT) will change at a different rate under the influence of AGE as compared to placebo. Twenty-three patients were enrolled, and 19 patients completed the study protocol. AGE 4 ml or the equivalent amount of placebo was given to subjects. Duration of the study was 1 year. S-allylcysteine (SAC), one of the active compound of AGE, was measured in the blood as a compliance marker. RESULTS: The mean change of the calcium score (volumetric method) for the AGE group (n = 9) was 7.5 +/- 9.4% over 1 year. The placebo group (n = 10) demonstrated an average increase in calcium scores of 22.2 +/- 18.5%, significantly greater than the treated cohort (P = 0.046). There were no significant differences in individual cholesterol parameters or C reactive protein between the groups. In patients randomized to AGE, there was a nonsignificant trend for improving cholesterol/high-density lipoprotein ratio (P = 0.07) and homocysteine level (P = 0.08). CONCLUSIONS: This small pilot study indicates the potential ability of AGE to inhibit the rate of progression of coronary calcification, as compared to placebo over 1 year. Should these findings be extended and confirmed in larger studies, garlic may prove useful for patients who are at high risk of future cardiovascular events.

Arteriosclerosis↗

PubMed2004

Purification, gene cloning and expression of an acidic phospholipase A2 from Agkistrodon shedaoensis Zhao.

A protein with the activity of phospholipase A(2) named asAPLA(2) was purified to homogeneity from the venom of Agkistrodon shedaoensis Zhao through DEAE-Sepharose CL-6B anion exchange column, Source S, and Mono Q FPLC. Its molecular weight was estimated to be 19 kD by SDS-PAGE, and its pI was about 3.5 by IEF analysis. It inhibited the platelet aggregation that was induced by 1 micromol/ L ADP, and the IC(50) was determined to be 6 micromol/L. Degenerating primer was designed and synthesized according to the N-terminal amino acid sequence of asAPLA(2). Its full-length cDNA was cloned by RT-PCR from the total RNA extracted from the snake venom gland. Its molecular weight and the pI are determined to be 13,649 and 4.39 respectively as calculated by DNAclub and DNAstar software according to the deduced amino acid sequence. Then the gene was cloned into the expression plasmid pET-40b(+) and expressed in E. coli BL21(DE3). Western blot analysis indicated that the expressed protein cross-reacted with the antibody against the native enzyme.

Agkistrodon↗

PubMed2004

Improved accuracy of noninvasive electron beam coronary angiography.

OBJECTIVES: We investigated the effect of electrocardiographic (ECG) triggering on the accuracy of coronary electron-beam angiography (EBA) as compared with invasive angiography. METHODS: One hundred thirty-three patients with suspected coronary disease were studied with intravenous coronary EBA and conventional coronary angiography. Patients were divided into 2 groups based upon ECG triggering on the EBA study. Patients were divided into 2 groups based upon different ECG triggering used: 80% R-R interval trigger method (group 1, n = 53) and end-systolic triggering (group 2, n = 80). End-systolic ECG triggering, which started at the end of the T wave in each study, was based on baseline heart rate. RESULTS: Overall sensitivity to detect a > or = 50% luminal stenosis was 69% in group 1 and 91% in group 2 (P = 0.002); specificity was 82% and 94% in group 1 and group 2, respectively (P < 0.001). Using newer triggering techniques (group 2) with EBA, the sensitivity, specificity, and accuracy for patients with disease of the left main coronary artery or 3 vessel disease was 100%, 94%, and 98%, respectively. Nonassessability of coronary segments on 3D-EBA images was reduced from 35% in group 1 to 9% in group 2 patients (P < 0.001). The number of motion-free coronary images increased from 67% to 95% from group 1 to group 2 (P < 0.0001). CONCLUSION: End-systolic ECG triggering improves accuracy, image quality, and assessability of segments of coronary EBA for the detection of angiographic coronary artery disease.

Algorithms↗

PubMed2004

Conditions affecting hydrodynamics-based gene delivery into mouse liver in vivo.

1. It has been demonstrated that the hydrodynamics-based procedure has high efficiency to deliver foreign genes into the liver. The widespread use of this procedure in gene function studies and as a treatment option for liver and other organ diseases puts considerable importance on the investigation of various conditions that affect hydrodynamics-based gene delivery into mouse liver in vivo. 2. Various conditions, including the volume, speed and solution of the injection and the state, gender and strain of the animal were manipulated to evaluate their effect on the expression levels in mice of human factor IX (hFIX) 8 h after tail vein injection of the plasmid pCMV-hFIX. 3. It was found that an injection volume of 2-2.5 mL and an injection speed of 5-7 s were very effective in delivering DNA into the mouse liver. Using Ringer's solution as an injection fluid increased the efficiency of hFIX expression. 4. Anaesthetized mice expressed higher hFIX than conscious mice. Males expressed higher hFIX than females. The ICR mouse strain demonstrated higher expression of the foreign gene than did the C57 strain. 5. The effects of these specific factors on hFIX expression may be caused by variations in hydrostatic pressure, the degree of liver damage and liver size. 6. It can be concluded that there are optimal conditions for hFIX expression in the liver. This information may be helpful for the application of hydrodynamics-based procedures in the investigation of gene expression and gene therapy.

Animals↗

PubMed2004

Imparting temperature sensitivity and attenuation in ferrets to A/Puerto Rico/8/34 influenza virus by transferring the genetic signature for temperature sensitivity from cold-adapted A/Ann Arbor/6/60.

The four temperature-sensitive (ts) loci identified in the PB1 and PB2 gene segments of cold-adapted A/Ann Arbor/6/60 influenza virus, the master donor virus for influenza A virus (MDV-A) FluMist vaccines, were introduced into a divergent A/Puerto Rico/8/34 influenza virus strain. Recombinant A/Puerto Rico/8/34 virus with these four introduced ts loci exhibited both ts and att phenotypes similar to those of MDV-A, which could be used as a donor virus for manufacturing large quantities of inactivated influenza virus vaccine against potential pandemic strains.

Animals↗