Biomedical subjects

Zhong-Hua Liu

Publications and source records attributed to Zhong-Hua Liu.

At least 19 recordsLinked to original sources

PubMed2006

Perioperative artificial nutrition in malnourished gastrointestinal cancer patients.

AIM: To investigate the potential role of perioperative nutrition in reducing complications and mortality in malnourished gastrointestinal cancer patients. METHODS: Four hundred and sixty-eight elective moderately or severely malnourished surgical patients with gastric or colorectal cancers defined by the subjective global assessment (SGA) were randomly assigned to 7 d preoperative and 7 d postoperative parenteral or enteral nutrition vs a simple control group. The nutrition regimen included 24.6+/-5.2 kcal /kg per d non-protein and 0.23+/-0.04 g nitrogen /kg per d. Control patients did not receive preoperative nutrition but received 600+/-100 kcal non-protein plus or not plus 62+/-16 g crystalline amino acids postoperatively. RESULTS: Complications occurred in 18.3% of the patients receiving nutrition and in 33.5% of the control patients (P=0.012). Fourteen patients died in the control group and 5 in those receiving nutrition. There were significant differences in the mortality between the two groups (2.1% vs 6.0%, P=0.003). The total length of hospitalization and postoperative stay of control patients were significantly longer (29 vs 22 d, P=0.014) than those of the studied patients (23 vs 12 d, P=0.000). CONCLUSION: Perioperative nutrition support is beneficial for moderately or severely malnourished gastrointestinal cancer patients and can reduce surgical complications and mortality.

Adult↗

PubMed2006

Primary reinforcing effects of nicotine are triggered from multiple regions both inside and outside the ventral tegmental area.

Nicotine is thought to be the key substance responsible for tobacco-smoking habits and appears to trigger reinforcement via the ventral tegmental area (VTA). Recently, multiple anatomical substrates for drug reinforcement have been identified in the vicinity of the ventral midbrain. In addition to the posterior portion of the VTA, the central linear nucleus raphé and the supramammillary nucleus of the posterior hypothalamus mediate drug reinforcement. Using intracranial self-administration procedures, we examined whether these regions mediate the reinforcing effects of nicotine. Rats learned to lever press for self-administration of nicotine into the posterior VTA, central linear nucleus, and supramammillary nucleus, suggesting a reinforcing action of nicotine in these regions. The rats did not self-administer nicotine into surrounding regions including the anterior VTA, substantia nigra, the region just dorsal to the posterior VTA, interpeduncular nucleus, or medial mammillary nucleus. The reinforcing effects of nicotine into the three brain regions were further confirmed by a two-lever discrimination procedure, in which rats learned to selectively respond between active and inactive levers. The reinforcing effects of nicotine administration into the posterior VTA, central linear nucleus, and supramammillary nucleus were blocked by coadministration of the nicotine receptor antagonist mecamylamine. The reinforcing effects of nicotine into the posterior VTA or central linear nucleus were attenuated by coadministration of the D2 receptor agonist quinpirole. These findings demonstrate that nicotine reinforcement involves multiple regions both inside and outside the VTA.

Animals↗

PubMed2006

Developmental competence of porcine parthenogenetic embryos relative to embryonic chromosomal abnormalities.

Parthenogenetically activated (PA) embryos exhibit delayed development, a lower blastocyst rate, and less successful development in vitro compared to in vitro fertilized (IVF) embryos. To investigate the possible mechanisms for unsuccessful parthenogenetic development, this study analyzed the chromosome abnormalities and developmental potential of porcine PA embryos. Mature oocytes were electrically activated and cultured in Porcine Zygote Medium-3 (PZM3) supplemented with 3 mg/ml BSA for 6, 7, or 8 days. The percentage of PA blastocysts was lower than that of IVF embryos on days 6 and 7 (16.4 +/- 7.4 vs. 28.7 +/- 3.7; 10.9 +/- 2.8 vs. 21.5 +/- 4.7, P < 0.05; respectively), and the PA blastocysts had significantly fewer nuclei than IVF blastocysts (23.2 +/- 1.8 vs. 29.7 +/- 0.8; 29.7 +/- 3.3 vs. 32.0 +/- 2.4, P < 0.05). The percentage of abnormal PA embryos (including embryos with condensed nuclei, arrested embryos and fragmented embryos) was higher than that of IVF embryos (PA: 52.9 +/- 12.8 vs. 16.4 +/- 7.4 on day 6), and increased with culture time (71.9 +/- 12.1 vs. 10.9 +/- 2.8. on day 7,and 75.0 +/- 22.6 vs. 12.1 +/- 2.3 on day 8, P < 0.05). The Day-6 PA blastocysts (n = 147) were divided into three classes according to the total number of nuclei (<20, 20-39, >40) and into three groups according to the morphological diameter (<150, 150-180, >180 microm). Of the haploid blastocysts, 56.1% had less than 20 nuclei, and 71.5% were less than 150 microm in diameter. Of all (114) blastocysts suitable for analysis, 55.5% displayed chromosomal abnormalities. Among chromosomal abnormalities in PA blastocysts, haploid blastocysts were most prevalent (43.6%), while polyploidy (4.4%) and mixoploidy (7.7%) embryos were less prevalent. Chromosomal abnormalities of porcine PA embryos might contribute to a higher rate of abnormal embryonic development. We suggest that a careful consideration should be given when using the blastocysts with smaller size, and establishing the optimum culture condition for PA embryos development in vitro.

Animals↗

PubMed2005

Expression of gamma-aminobutyric acid A receptor subunits alpha1, beta1, gamma2 mRNA in rats with hepatic encephalopathy.

AIM: To investigate the mRNA expression of gamma-aminobutyric acid A (GABA(A)) receptor subunits alpha(1), beta(1), gamma(2) in different parts of the brain of rats with hepatic encephalopathy. METHODS: Twelve adult male Sprague-Dawley rats were randomly divided into two groups: (1) hepatic encephalopathy model group (n = 6), which was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg/kg) for three consecutive days; (2) control group (n = 6), in which the rats were treated with same dose of normal saline solution. After the freeze slice of cerebrum was made, in situ hybridization was used to detect the mRNA of GABAA receptor subunits alpha(1), beta(1), and gamma(2) in rat cerebral cortex, basal nuclei, substantia nigra and hippocampi. Image data were collected and analyzed quantitatively by QWin550CW model image signal gather and analysis system. RESULTS: In rats with hepatic encephalopathy, mRNA expression levels of GABA(A) receptor subunits alpha(1), beta(1) increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis and hippocampi (144.7+/-15.67/184.14+/-4.41, 60.61+/-33.66/113.07+/-32.44, 87.71+/- 21.25/128.40+/-18.85, 122.34+/-5.56/161.60+/-4.56, 123.29+/-5.21/140.65+/-4.15, 123.40+/-4.42/140.09+/-4.52, 124.76+/-4.18/140.09+/-4.12, 141.62+/-15.09/182.80 +/-5.20, 69.13+/-30.74/134.21+/-43.76, 87.87+/-25.16/151.01+/-19.49, 122.14+/-6.30 /162.33+/-3.92, 122.81+/-5.09/137.19+/-7.12, 123.00+/-4.63/138.11+/-5.92, 125.75 +/-2.43/138.81+/-6.10, P<0.01), but did not change in the cerebral cortex compared to the control group. Similar changes were found in the mRNA expression levels of GABA(A) receptor subunit gamma(2), which increased significantly in basal nuclei, substantia nigra pars compacta, substantia nigra pars reticularis (136.81+/-26.41/167.97+/-16.23, 51.00+/-36.14/113.18+/-36.52, 86.35+/-20.30/ 126.90+/-19.74, P<0.01), CA1 of hippocampal (162.15+/-9.05/178.62+/-6.45, P<0.05), and no changes were found in the cerebral cortex and CA2, CA3, CA4 of hippocampi. CONCLUSION: In rats with hepatic encephalopathy, mRNA expression levels of GABA(A) receptor subunits alpha(1), beta(1), gamma(2) increase significantly in basal nuclei, substantia nigra and hippocampi, suggesting that the changes of mRNA expression levels in GABA(A) receptor subunits may contribute to the pathogenesis of hepatic encephalopathy.

Animals↗

PubMed2005

The functional divide for primary reinforcement of D-amphetamine lies between the medial and lateral ventral striatum: is the division of the accumbens core, shell, and olfactory tubercle valid?

When projection analyses placed the nucleus accumbens and olfactory tubercle in the striatal system, functional links between these sites began to emerge. The accumbens has been implicated in the rewarding effects of psychomotor stimulants, whereas recent work suggests that the medial accumbens shell and medial olfactory tubercle mediate the rewarding effects of cocaine. Interestingly, anatomical evidence suggests that medial portions of the shell and tubercle receive afferents from common zones in a number of regions. Here, we report results suggesting that the current division of the ventral striatum into the accumbens core and shell and the olfactory tubercle does not reflect the functional organization for amphetamine reward. Rats quickly learned to self-administer D-amphetamine into the medial shell or medial tubercle, whereas they failed to learn to do so into the accumbens core, ventral shell, or lateral tubercle. Our results suggest that primary reinforcement of amphetamine is mediated via the medial portion of the ventral striatum. Thus, the medial shell and medial tubercle are more functionally related than the medial and ventral shell or the medial and lateral tubercle. The current core-shell-tubercle scheme should be reconsidered in light of recent anatomical data and these functional findings.

Animals↗

PubMed2005

Elevated plasma tissue-type plasminogen activator (t-PA) and soluble thrombomodulin in patients suffering from severe acute respiratory syndrome (SARS) as a possible index for prognosis and treatment strategy.

OBJECTIVE: To detect the presence of endothelial injury in patients with severe acute respiratory syndrome (SARS) via enhanced levels of tissue-type plasminogen activator (t-PA) and soluble thrombomodulin (sTM). METHODS: Case patients were from Xuanwu Hospital (Capital University of Medical Sciences, Beijing, China), and all of them met clinical criteria for SARS. Healthy controls were some of the hospital employees. Endothelial injury bio-markers tPA and sTM were detected by commercial ELISA-methods. RESULTS: Classic plasma markers of endothelial injury, tPA and sTM significantly elevated in SARS patients in comparison to controls [t-PA: 1.48 +/- 0.16 nmol/L versus 0.25 +/- 0.03 nmol/L (P<0.0001), and sTM: 0.26 +/- 0.06 nmol/L versus 0.14 +/- 0.02 nmol/L (P<0.05)]. The only patient who died had extremely high levels of these endothelial injury markers (t-PA: 2.77 nmol/L and sTM: 1.01 nmol/L). The likelihood ratio analysis indicated the excellent discriminating power for SARS at the optimal cut-point of 0.49 nmol/L for tPA and 0.20 nmol/L for sTM, respectively. Significant numerical correlations were found among these endothelial injury markers in SARS patients. The numerical coefficient of correlation Pearson r between t-PA and sTM was 0.5867 (P<0.05). CONCLUSION: Increased plasma concentrations of tPA and sTM in patients with SARS suggest the possibility of endothelial injury. SARS patients might need anticoagulant therapy or fibrinolytic therapy in order to reverse intraalveolar coagulation, microthrombi formation, alveolar and interstitial fibrin deposition. It may not only provide a useful treatment and prognostic index but also allow a further understanding of the pathological condition of the disease.

Adult↗

PubMed2005

[The multi-level Meta analysis model combining individual level data with aggregative level data].

OBJECTIVE: To explore the multi-level Meta analysis model combining individual level data with aggregative level data and its application in medicine. METHODS: The difference in respect to "decreased hemoglobin A(1c)" between treatment with roglizatone and treatment without roglizatone was obtained by combining individual level data from clinical trial of roglizatone natrium with aggregative level data from literatures. This endeavor was regarded as an example to construct the multi-level Meta analysis model combining individual level data with aggregative level data. RESULTS: The baseline hemoglobin A(1c) was 9% and the dose of drug was 4 mg per day. The average difference in "decreased hemoglobin A(1c)" between treatment with and without roglizatone was 0. 464%, with a 95% CI from 0.168% to 0.760%. CONCLUSION: In case that individual data are available, the multi-level Meta analysis model combining individual level data with aggregative level data can utilize the data resources adequately and the results obtained should be more accurate.

Data Interpretation, Statistical↗

PubMed2005

[Sequencing and analysis of Vibrio cholerae typing phage VP3 genome].

DNA sequence and the genome of phage VP3 (a typing phage of V. cholera) were analyzed. A random library of VP3 DNA was constructed by shot-gun library method. The VP3 genome sequence was assembled with contigs sequences, the gaps between different contigs were filled with sequencing data from primer walking. ORFs were predicted; Phylogeny of DNA polymerase sequences was analyzed to determine the class of VP3; The activity of putative promoter genes were analyzed using lacZ report system. VP3 genome is a 39504bp of circular double-stranded DNA. Twenty-seven out of forty-nine putative ORFs were annotated; twenty gene products were homologous with T7-like phages, including DNAP, DNA replicative protein, capsid, tail tubular, tail fiber protein, and DNA packaged protein. The activity of the putative promoter regions was confirmed through cloning those regions to LacZ-fuse plasmid pRS1274 and analysis of the expression of beta galactosidase. The complete genomic sequence of VP3 and phylogenetic tree analysis suggests VP3 is a member of T7 phage family.

Bacteriophage T7↗

PubMed2004

Decrease of ventral tegmental area dopamine neuronal activity in nicotine withdrawal rats.

The present study was designed to examine the ventral tegmental area (VTA) dopamine neuronal activity in nicotine withdrawal rats by means of in vivo single-unit extracellular recordings. Animals were treated with nicotine base (6 mg/kg/day, s.c.) four times daily for 12 days. One day after the last nicotine administration, the firing rates of the VTA dopamine neurons were found to be significantly decreased. Following 2, 3, 5 and 10 days of nicotine withdrawal, however, the firing rates returned to the control levels. The number of spontaneously active dopamine cells was not altered at any time points. The results indicate that the VTA dopamine neuronal activity is reduced during the first day of nicotine withdrawal.

Animals↗

PubMed2004

Effect of chronic treatment of ohmefentanyl stereoisomers on cyclic AMP formation in Sf9 insect cells expressing human mu-opioid receptors.

The binding affinity of ohmefentanyl stereoisomers for mu-opioid receptors and the effect of chronic ohmefentanyl stereoisomers pretreatments on intracellular cAMP formation were investigated in Sf9 insect cells expressing human mu-opioid receptors (Sf9-mu cells). Competitive assay of [3H]ohmefentanyl binding revealed that these isomers had high affinity for micro-opioid receptors in Sf9-mu cells. Isomer F9204 had the highest affinity for mu-opioid receptors with the Ki value of 1.66 +/- 0.28 nM. After pretreated Sf9-mu cells with increasing concentrations of these isomers for 6 h, addition of naloxone (1 microM) precipitated an overshoot of foskolin-stimulated cAMP accumulation. The ability of these isomers to induce cAMP overshoot differed greatly with the order of F9202>F9205>F9208>F9206>F9204>F9207. Of these isomers, F9202 was 2.7-fold less potent than F9204 in receptor binding affinity, but 71.5-fold more potent in ability to induce cAMP overshoot. These results suggested that there was a significant stereo-structural difference among ohmefentanyl stereoisomers in ability to induce naloxone-precipitated cAMP overshoot in Sf9-mu cells.

Analgesics↗

PubMed2004

Mitochondrial DNA heteroplasmy in calves cloned by using adult somatic cell.

Adult somatic cell cloned calves were produced by somatic cell nuclear transfer prepared by fusion of cultured ear fibroblast from a Holstein cow into enucleated oocytes of Luxi Yellow cow. In order to determinate the source of mitochondrial DNA of cloned calves, we designed the breed-specific PCR primers by aligning the known D-loop sequences of Bos taurus and analyzed the displacement loop sequences of five live cloned calves by breed-specific primers PCR. The results demonstrated that mtDNA originated from Holstein breed and that from Luxi breed co-exist in all five live calves.

Animals↗

PubMed2003

Opioid activity of C8813, a novel and potent opioid analgesic.

Compound trans-4-(p-bromophenyl)-4-(dimethylamino)-1-(2-thiophen-2-yl-ethyl)-cyclohexanol (C8813), structurally unrelated to morphine, is a novel analgesic. The present study examined the antinociception, opioid receptor selectivity and in vitro activity of C8813. The antinociceptive activity was evaluated using mouse hot plate and acetic acid writhing tests. In mouse hot plate test, the antinociceptive ED(50) of C8813 was 11.5 microg/kg, being 591 times and 3.4 times more potent than morphine and fentanyl respectively. In mouse writhing test, the antinociceptive ED(50) of C8813 was 16.9 microg/kg, being 55 times and 2.3 times more active than morphine and fentanyl respectively. In the opioid receptor binding assay, C8813 showed high affinity for mu-opioid receptor (K(i) = 1.37 nM) and delta-opioid receptor (K(i) = 3.24 nM) but almost no affinity for kappa-opioid receptor (at 1 microM). In the bioassay, the inhibitory effect of C8813 in the guinea-pig ileum (GPI) was 16.5 times more potent than in the mouse vas deferens (MVD). The inhibitory effects of C8813 in the GPI and MVD could be antagonized by mu-opioid receptor antagonist naloxone and delta-opioid receptor antagonist ICI174,864 respectively. However, the inhibitory effect of C8813 in the rabbit vas deferens was very weak. These results indicated that C8813 was a potent analgesic and a high affinity agonist for the mu- and delta-opioid receptors.

Analgesics, Opioid↗

PubMed2003

Comparison of developmental capacity for intra- and interspecies cloned cat (Felis catus) embryos.

Interspecies nuclear transfer is an invaluable tool for studying nucleus-cytoplasm interactions; and at the same time, it provides a possible alternative to clone animals whose oocytes are difficult to obtain. In the present study, we investigated the possibility of cloning cat embryos using rabbit oocytes, and compared the developmental capacity; the timing of embryogenesis of the cat-rabbit cloned embryos with that of the cat-cat or the rabbit-rabbit cloned embryos. When cultured in M199, the rate of blastocyst formation of the cat-rabbit embryos was 6.9%, which was not significantly different than that of the cat-cat embryos (10.5%). However, the rate of blastocyst formation of rabbit-rabbit embryos (22.9%) was significantly greater than that of both the cat-rabbit and the cat-cat embryos (P < 0.05). The timing of the first three cleavages for the cat-rabbit embryos was similar to that of the rabbit-rabbit embryos, but significantly faster than that of the cat-cat embryos (P < 0.05), while the time to form blastocysts was similar to that of cat-cat embryos, but significantly slower than that of the rabbit-rabbit embryos (P < 0.05). Both M199 and SOF medium were evaluated for culturing cat-rabbit embryos; the rate of blastocyst formation in SOF (14.5%) was significantly greater than that in M199 (6.9%) (P < 0.05). These results demonstrate that: (1) the cat-rabbit embryos possess equal developmental capacity as cat-cat embryos; (2) the timing of the first three cleavages for the cat-rabbit embryos is recipient-specific, while the time to form blastocysts is donor nucleus-specific; and (3) SOF medium may be beneficial to overcome the morula-to-blastocyst block for cat-rabbit cloned embryos.

Animals↗

PubMed2003

Suppression of morphine-induced conditioned place preference by l-12-chloroscoulerine, a novel dopamine receptor ligand.

The effect of l-12-chloroscoulerine (l-CSL), a novel ligand with dual dopamine D1 receptor agonistic and D2 receptor antagonistic actions, on the development of morphine-induced conditioned place preference (CPP) was investigated in mice. Morphine (10 mg/kg)-induced place preference was dose dependently suppressed by coadministration of l-CSL (5, 10 and 20 mg/kg), which induced neither place preference nor place aversion when administered alone at a dose of 20 mg/kg. The D1 receptor antagonist SCH23390 (0.1 mg/kg) suppressed, whereas the D2 receptor agonist (+/-)-2-(N-phenylethyl-N-propyl)-amino-5-hydroxytetralin (PPHT) (0.5 mg/kg) had no influence on the development of morphine-induced place preference. However, SCH23390 (0.1 mg/kg) did not affect, whereas PPHT (0.5 mg/kg) reversed the suppressive effect of l-CSL on the development of morphine-induced place preference. These results indicate that l-CSL suppresses the development of place preference of morphine by blocking D2 receptors.

Animals↗

PubMed2003

The effects of different donor cells and passages on development of reconstructed embryos.

In order to study the effects of different donor cells and passages on development of nuclear transfer embryos, we constructed embryos by electrofusing several kinds of donor cells into enucleated M II oocytes from Kun Ming (KM) mouse. These cells include 2-cell embryonic blastomeres, KMW embryonic stem (ES) cells, fetal fibroblast, ear fibroblast, tail tip fibroblast, sertoil cells and spermatogonia. Meanwhile, we compared the effects of passage numbers of fetal fibroblast cells on developmental competency after nuclear transfer. We found that 7.4% of reconstructed embryos from 2-cell embryonic blastomeres and 0.7% from ES cell could develop to blastocyst in vitro; embryos from fetal fibroblast could only develop to morula stage with the rate of 0.2%; embryos from spermatogonia could only develop to 8-cell stage and the rate was 0.3%; embryos respectively from ear fibroblast, sertoli cell and tail tip fibroblast could only develop to 4-cell stage. Although 2-cell development rate of embryos reconstructed from fetal fibroblast in first passage was significantly lower than those from the 2nd, the 3rd and the 4th passage, embryos from different passages could develop to 8-cell stage except the 3rd passage. The result indicated that it is more difficult for terminally differentiated cell nuclei to be reprogrammed in enucleated M II oocytes than for low differentiated cell nuclei. The reason of low development rate from ES cells maybe that most of ES cells was at S stage of the cell cycle, which out of coordination with M II oocytes. We could conclude that culture and passage of donor cells might be benefit to nucleus reprogramming.

Animals↗

PubMed2003

Binding affinity to and dependence on some opioids in Sf9 insect cells expressing human mu-opioid receptor.

AIM: To investigate the receptor binding affinity and naloxone-precipitated cAMP overshoot of dihydroetorphine, fentanyl, heroin, and pethidine in Sf9 insect cells expressing human mu-opioid receptor (Sf9-mu cells). METHODS: Competitive binding assay of [3H]ohmefentanyl was used to reveal the affinity for mu-opioid receptor in Sf9-mu cells. [3H]cAMP RIA was used to determine cAMP level. Antinociceptive activity was evaluated using degree 55 mouse hot plate test. Naloxone-precipitated withdrawal jumping was used to reflect physical dependence in mice. RESULTS: All drugs displayed antinociceptive activity and produced physical dependence in mice. The K(i) values of dihydroetorphine, fentanyl, heroin, and pethidine in competitive binding assay were (0.85+/-0.20) nmol, (59.1+/-11.7) nmol, (0.36+/-0.13) micromol, and (12.2+/-3.8) micromol respectively. The binding affinities of these drugs for mu-opioid receptor in Sf9-mu cells were paralleled to their antinociceptive activities in mice. After chronic pretreatment with these drugs, naloxone induced cAMP withdrawal overshoot in Sf9-mu cells. The dependence index in Sf9-mu cells was calculated as K(i) value in competitive binding assay over EC(50) value in naloxone-precipitated cAMP assay. The physical dependence index in mice was calculated as antinociceptive ED(50)/withdrawal jumping cumulative ED(50). There was a good linear correlation between dependence index in Sf9-mu cells and physical dependence index in mice. CONCLUSION: The Sf9-mu cells could be used as a cell model to evaluate the receptor binding affinity and physical dependent liability of analgesic agents.

Analgesics, Opioid↗

PubMed2003

Purification and characterization of a neurotoxic peptide huwentoxin-III and a natural inactive mutant from the venom of the spider Selenocosmia huwena Wang (Ornithoctonus huwena Wang).

A novel neurotoxic peptide, named huwentoxin-III, and a natural mutant have been isolated from the venom of the spider Selenocosmia huwena Wang (Ornithoctonus huwena Wang). The average molecular weights of the two peptides were determined as 3853.35 and 3667.40 by mass spectrometry, respectively. Huwentoxin-III has 33 amino acid residues containing 6 cysteine residues. Its natural mutant is only truncated a tryptophan residue from C-terminals of huwentoxin-III. The sequences of the two peptides show 70.5% sequence similarity with that of lectin-like peptide SHL-I previously isolated from the venom of the same spider, while they cannot agglutinate human erythrocytes. Huwentoxin-III can reversibly paralyze cockroaches for several hours with an ED(50) of (192.95 +/- 120.84) microg/g (P=0.95) (mean +/- SD) and can enhance the muscular contractions elicited by stimulating the nerve of the isolated rat vas deferens, however, the mutant of huwentoxin-III has no such effect, which suggests that Trp33 was an important residue related to the biological function of huwentoxin-III.

Amino Acid Sequence↗

PubMed2002

Interspecies implantation and mitochondria fate of panda-rabbit cloned embryos.

Somatic cell nuclei of giant pandas can dedifferentiate in enucleated rabbit ooplasm, and the reconstructed eggs can develop to blastocysts. In order to observe whether these interspecies cloned embryos can implant in the uterus of an animal other than the panda, we transferred approximately 2300 panda-rabbit cloned embryos into 100 synchronized rabbit recipients, and none became pregnant. In another approach, we cotransferred both panda-rabbit and cat-rabbit interspecies cloned embryos into the oviducts of 21 cat recipients. Fourteen recipients exhibited estrus within 35 days; five recipients exhibited estrus 43-48 days after embryo transfer; and the other two recipients died of pneumonia, one of which was found to be pregnant with six early fetuses when an autopsy was performed. Microsatellite DNA analysis of these early fetuses confirmed that two were from giant panda-rabbit cloned embryos. The results demonstrated that panda-rabbit cloned embryos can implant in the uterus of a third species, the domestic cat. By using mitochondrial-specific probes of panda and rabbit, we found that mitochondria from both panda somatic cells and rabbit ooplasm coexisted in early blastocysts, but mitochondria from rabbit ooplasm decreased, and those from panda donor cells dominated in early fetuses after implantation. Our results reveal that mitochondria from donor cells may substitute those from recipient oocytes in postimplanted, interspecies cloned embryos.

Abdominal Muscles↗