276
|
Chang GQ, Gaitan A, Hao Y, Wong F. Correlation of DNA fragmentation and chromatin condensation in apoptotic nuclei of the Ser 6 mouse retina. Microsc Res Tech 1997; 36:123-9. [PMID: 9015258 DOI: 10.1002/(sici)1097-0029(19970115)36:2<123::aid-jemt5>3.0.co;2-q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The form of cell death known as apoptosis was first described in thymocytes. The hallmarks of apoptosis include chromatin condensation, membrane blebbing, formation of apoptotic bodies, and DNA fragmentation. DNA fragmentation can be visualized morphologically by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method that labels the cut DNA ends. However, at the light microscopic (LM) level, TUNEL-positive nuclei cannot readily be correlated with the other hallmarks of apoptosis. In the retina, chromatin condensation and DNA fragmentation are the major features of developmental cell death as well as photoreceptor degeneration. We performed TUNEL at the electron microscopic (EM) level, which permitted correlation of DNA fragmentation with chromatin condensation. We studied the retinas of transgenic mice (Ser 6) expressing the Pro347Ser mutant rhodopsin gene during developmental cell death (age 7 days) and photoreceptor degeneration (age 21 days). We found that 90% of the nuclei showing chromatin condensation were TUNEL positive as well. Our results demonstrated DNA fragmentation and chromatin condensation in the same cells as they underwent apoptosis in vivo, confirming the notion that these processes are concomitant events, and by implication, that activation of an endogenous endonuclease is an important step in the death process of retinal neurons.
Collapse
|
277
|
Tso MO, Li WW, Zhang C, Lam TT, Hao Y, Petters RM, Wong F. A pathologic study of degeneration of the rod and cone populations of the rhodopsin Pro347Leu transgenic pigs. TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 1997; 95:467-79; discussion 479-83. [PMID: 9440185 PMCID: PMC1298373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE Transgenic pigs with rhodopsin (Pro347Leu) mutation exhibited rod-cone degeneration. We compared the pathologic characteristics of the rod degeneration versus those of the cone cells. METHODS The posterior and peripheral retinas of these transgenic pigs of age 4, 6, 8, 12, 24 and 33 weeks and normal pigs of age 4 and 8 weeks were studied by light and EM and morphometry. RESULTS The pathologic changes observed in the posterior and peripheral retinas of the transgenic pigs could be conveniently described in 3 phases: I) an initial phase of rapid and extensive degeneration of the rod cells in the first 6 weeks of age; II) an acute phase of cone cell degeneration involving approximately half of the population and lingering rod degeneration in the 6 to 12 weeks of age; and III) a partial cone recovery to be followed by a chronic degenerative phase of the remaining cones cells from 12 to 33 weeks of age. CONCLUSION Our study showed that the degenerative changes of rod cells could be differentiated from those of the cone cells. Cone and rod populations degenerated along different time schedule with different pathologic features. Hence, treatment for retinitis pigmentosa might vary with the different stages of the disease.
Collapse
|
278
|
Abstract
PURPOSE This study aimed to assess the influence of the level of initial injury on the long-term recovery kinetics of radiation damage in the central nervous system using a rat spinal cord model. METHODS AND MATERIALS The adult rat spinal cord (C2-T2) was initially given two or three daily fractions of 9 Gy, or three daily fractions of 10.25 Gy. At day 4 or weeks 6, 8, 12, 20, 28, 40, or 52, animals were reirradiated with graded single doses of X rays. The end point was forelimb paralysis caused by white-matter necrosis. RESULTS Latent times to paralysis as measured from the date of the initial treatment increased with increasing time interval between initial treatment and reirradiation but decreased with increasing size of initial injury. Retreatment ED50s were 14.1, 14.8, 15.4, 16.3, and 16.2 Gy for animals reirradiated at day 4 and weeks 8, 12, 20, and 28, respectively, after an initial dose of 9 Gy x 2. After 9 Gy x 3, the retreatment ED50s at day 4 and weeks 6, 8, 12, 20, 28, 40, and 52 were 10.0, 9.9, 9.8, 12.0, 13.9, 14.6, 14.7, and 15.5 Gy, respectively. For an initial dose of 10.25 Gy x 3, the retreatment ED50s at day 4 and weeks 8, 12, 20, 28, and 40 were 5.8, 6.1, 8.4, 10.6, 12.2, and 13.3 Gy, respectively. Using the linear-quadratic (LQ) model, alpha/beta of 3.0 Gy, to quantitate the biological effect of the different retreatment schedules, the initial doses of 9 Gy x 2 or 3, or 10.25 Gy x 3 were found to represent 47, 71, and 89% of the extrapolated response dose (ERD), respectively, and no significant increase in tolerance was observed for retreatment given within 8 weeks of initial treatment. Significant long-term recovery was observed thereafter and increased with increasing time interval to retreatment. The retreatment tolerance and radiation damage recovered at different intervals were influenced by the initial dose. Using direct analysis, the recovery kinetics could be best described by introducing a time function consisting of a linear and quadratic time component dependent on initial dose to the LQ model. CONCLUSION These results are consistent with the presence of significant long-term recovery of radiation damage in rat spinal cord, and suggest that the size of the initial damage influences the recovery kinetics, and hence the retreatment tolerance.
Collapse
|
279
|
Chao H, Wang L, Wang J, Hao Y, Meng Q, Li K, Feng B. [Preliminary study on oncogene MDM2 in acute leukemias]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 1997; 18:13-6. [PMID: 15622743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To explore the causes of MDM2 gene overexpression. METHODS The amplification and overexpression of MDM2 gene in 41 acute leukemia patients and two leukemic cell lines (K051 and HL60) were studied by using Southern blot, dot hybridyzation and RT-PCR techniques. RESULTS Overexpression of MDM2 gene was found in 51.2% (21/41) of the patients and HL60 cell line, but no amplification of the gene was found in all the patients and the two cell lines. CONCLUSION The level of MDM2 gene expression was related to the prognoses of the patients but not to FAB subtypes of acute leukemias.
Collapse
|
280
|
Hao Y, Zhang J, Yi C, Qian W. Abnormal change of p53 gene in gastric and precancerous lesions and APC gene deletion in gastric carcinoma and near tissues. Curr Med Sci 1997; 17:75-8. [PMID: 9639793 DOI: 10.1007/bf02888238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/1995] [Indexed: 02/07/2023]
Abstract
p53 gene mutation (exon4, 5, 6, 7, 8 and intron6) in gastric cancer and precancerous lesions and p53 gene (exon4 and ontron6), APC gene deletion in gastric carcinomas were studied by PCR/SSCP and PCR/RFLP. Results showed mutation rate of p53 in metaplasia, dysplasia and gastric carcinoma was 37.5% (3/8), 42.17% (8/19), 53.33 (16/30) respectively. There was significant difference among groups of metaplasia, dysplasia, cancer and normal controls. No exon8 mutation was found in metaplasia and dysplasia, but 4 cases were found to have exon8 mutation in cancer group. It is suggested that exon8 mutation occurs at the late stage of gastric cancer, but exon 5, 6, 7 mutation occur in the course of precancerous lesion to cancer. Loss of heterozygosity (LOH) of exon4, intron6, APC was 47, 37% (9/19), 8.73% (2/23), 16.67% (3/18) respectively. LOH of exon4 had something to do with poor differentiation, lymph node metastasis, depth of invasion. LOH of exon4 may be of prognostic marker of gastric cancer. We are led to conclude that p53 gene mutation is an early event and perhaps work together with ras oncogene in gastric carcinogenesis.
Collapse
|
281
|
Hao Y. [Dislocation of intraocular lens inferior loop and ciliochoroidal detachment caused by blunt contusion: a report of two cases]. YAN KE XUE BAO = EYE SCIENCE 1996; 12:216. [PMID: 15508260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
|
282
|
Hui Y, Hao Y, Chen X, Jing S, Dai Z. Relationship between some humoral factors and left ventricular hypertrophy in essential hypertension. Chin Med J (Engl) 1996; 109:885-7. [PMID: 9275376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To evaluate the relationship between certain humoral factors and left ventricular hypertrophy (LVH) in essential hypertension. PATIENTS AND METHODS 62 essential hypertension (EH) patients (32 men, 30 women; mean age, 55 years) and 20 normotensive healthy subjects (10 men, 10 women: mean age, 52 years) were studied. EH patients were divided into LVH group and non-LVH group by echocardiography. After an overnight fast, blood samples were taken for the determination of parathyroid hormone (PTH), angiotensin II (ATII) and aldosterone (ALD) by radioimmunoassay. RESULTS There was a significant difference in PTH. AT II and ALD between the EH group and control group. Furthermore, in LVH group PTH, ATII and ALD elevated significantly as compared with non-LVH group. In addition, we found that LVMI (left ventricular mass index) correlated with ATII (r = 0.342, P < 0.01) and ALD (r = 0.356, P < 0.01). There was a more significant correlation between LVMI and PTH (r = 0.422, P < 0.0025). CONCLUSIONS Some humoral factors are important determinants of LV mass. Besides the reninangiotensin-aldosterone system, PTH might play an important role in cardiac hypertrophy.
Collapse
|
283
|
Zhu Z, Hao Y, Gershon MD, Ambron RT, Gershon AA. Targeting of glycoprotein I (gE) of varicella-zoster virus to the trans-Golgi network by an AYRV sequence and an acidic amino acid-rich patch in the cytosolic domain of the molecule. J Virol 1996; 70:6563-75. [PMID: 8794291 PMCID: PMC190697 DOI: 10.1128/jvi.70.10.6563-6575.1996] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Previous studies suggested that varicella-zoster virus (VZV) envelope glycoproteins (gps) are selectively transported to the trans-Golgi network (TGN) and that the cytosolic domain of gpI (gE) targets it to the TGN. To identify targeting signals in the gpI cytosolic domain, intracellular protein trafficking was studied in transfected cells expressing chimeric proteins in which a full-length or mutated gpI cytosolic domain was fused to the gpI transmembrane domain and interleukin-2 receptor (tac) ectodomain. Expressed protein was visualized with antibodies to tac. A targeting sequence (AYRV) and a second, acidic amino acid-rich region of the gpI cytosolic domain (putative signal patch) were each sufficient to cause expressed protein to colocalize with TGN markers. This targeting was lost when the tyrosine of the AYRV sequence was replaced with glycine or lysine, when arginine was replaced with glutamic acid, or when valine was substituted with lysine. In contrast, tyrosine could be replaced by phenylalanine and valine could be substituted with leucine. Mutation of alanine to aspartic acid or deletion of alanine abolished TGN targeting. Exposure of transfected cells to antibodies to the tac ectodomain revealed that the TCN targeting of expressed tac-gpI chimeric proteins occurred as a result of selective retrieval from the plasmalemma. These data suggest that the AYRV sequence and a second signaling patch in the cytosolic domain of gpI are responsible for its targeting to the TGN. The observations also support the hypothesis that the TGN plays a critical role in the envelopment of VZV.
Collapse
|
284
|
He S, Hao Y, Li X. [New flexible open-loop anterior chamber lens in secondary implantation]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1996; 32:282-4. [PMID: 9590845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To determine the efficacy of new flexible open-loop anterior chamber intraocular lens (AC IOL) in secondary implantation. METHOD Secondary AG-IOL implantation in 35 eyes including 28 with traumatic cataract and 7 with senile cataract was performed 3 months to 2.5 years after primary cataract extraction. All patients were followed up for at least 6 months. RESULTS Of the 35 eyes, 27 (77.1%) had a final visual acuity of 0.5 or better and 11 (31.4%) had 1.0 or better. CONCLUSION New flexible open-loop AC IOL is safe and effective for secondary IOL implantation.
Collapse
|
285
|
Young SW, Qing F, Harriman A, Sessler JL, Dow WC, Mody TD, Hemmi GW, Hao Y, Miller RA. Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI. Proc Natl Acad Sci U S A 1996; 93:6610-5. [PMID: 8692865 PMCID: PMC39073 DOI: 10.1073/pnas.93.13.6610] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Gadolinium(III) texaphyrin (Gd-tex2+) is representative of a new class of radiation sensitizers detectable by magnetic resonance imaging (MRI). This porphyrin-like complex has a high electron affinity [E1/2 (red.) approximately = -0.08 V versus normal hydrogen electrode] and forms a long-lived pi-radical cation upon exposure to hydrated electrons, reducing ketyl radicals, or superoxide ions. Consistent with these chemical findings, Gd-tex2+ was found to be an efficient radiation sensitizer in studies carried out with HT29 cells in in vitro as well as in in vivo single and multifraction irradiation studies with a murine mammary carcinoma model. Selective localization of Gd-tex2+ in tumors was confirmed by MRI scanning.
Collapse
|
286
|
Hu M, Hao Y, Hui Y. [Promotion of c-fos oncogene expression in cultured rabbit lens epithelial cells by macrophages]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1996; 32:104-6. [PMID: 9206224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE This study was designed to test the hypothesis that inflammatory cells deposited on the surface of implanted intraocular lens stimulate the proliferation of residual lens epithelial cells. METHODS Immunocytochemical ABC methods with purified anti-human Fos protein serum antibody was used to stain the cultured rabbit lens epithelial cells incubated with rabbit macrophages and macrophage-conditioned medium (MCM). RESULTS The lens epithelial cell growth was faster in the cultures with macrophages and MCM than in the controls. Fos protein positive staining was found in the nuclei of epithelial cells cultured with macrophages for 4 hours, and of the cells with MCM for one hour; whereas the staining was negative in the cells of control cultures. CONCLUSION Macrophages promote c-fos oncogene expression in the lens epithelial cells, that might be mediated by bioactive factors secreted by macrophages.
Collapse
|
287
|
Li S, Hao Y, Gao S. [Changes in hematoporphyrin in patients with gastric and hepatic carcinoma and their clinical significance]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1996; 18:34-6. [PMID: 8732109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The fluorescence spectroscopy of porphyrin molecule in blood was determined with photoluminescence fluorescence spectroscope in 139 patients with gastric carcinoma, 76 with hepatic carcinoma, 110 with gastric ulcer and chronic gastritis, 168 with liver cirrhosis and 33 normals as controls. The results showed that the peaks of Zinc porphyrin and protoporphyrin in patients with cancer were significantly higher than those in patients with benign disease, the peak of protoporphyrin being two to three times higher in the former groups of patients than that in the latter (P < 0.01). Protoporphyrin could be used as a marker to screen and diagnose gastric and hepatic carcinoma.
Collapse
|
288
|
Brierley JD, Keane TJ, Cummings B, Hao Y. The absence of an adverse effect of prolongation of radiation treatment of primary rectal adenocarcinoma. Clin Oncol (R Coll Radiol) 1996; 8:97-101. [PMID: 8859606 DOI: 10.1016/s0936-6555(96)80114-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Many reports have shown a deleterious effect from the prolongation of radiation treatment duration on local control of squamous cell carcinomas in a variety of sites. To study whether a similar effect was found in adenocarcinoma of the rectum, a retrospective review was performed of 353 patients treated by external beam radiation therapy for primary adenocarcinoma of the rectum. At 4 years, the local control rate for mobile tumours was 25 percent; for fixed tumours it was 7 percent. By multiple Cox regression analysis, the only factor statistically significant for local control was tumour fixation (P=0.02). Neither treatment length (P=0.44), nor the presence of an interruption in treatment (P=0.41) was significant. The possible explanations for these observations are discussed.
Collapse
|
289
|
Kim J, Hao Y, Jang D, Wong C. 334Influence of sequence of top-up doses on repair kinetics in rat spinal cord. Radiother Oncol 1996. [DOI: 10.1016/s0167-8140(96)80343-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
290
|
Zhu Z, Gershon MD, Hao Y, Ambron RT, Gabel CA, Gershon AA. Envelopment of varicella-zoster virus: targeting of viral glycoproteins to the trans-Golgi network. J Virol 1995; 69:7951-9. [PMID: 7494308 PMCID: PMC189740 DOI: 10.1128/jvi.69.12.7951-7959.1995] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Previous studies suggested that varicella-zoster virus derives its final envelope from the trans-Golgi network (TGN) and that envelope glycoproteins (gps) are transported to the TGN independently of nucleocapsids. We tested the hypothesis that gpI is targeted to the TGN as a result of a signal sequence or patch encoded in its cytosolic domain. cDNAs encoding gpI wild type (wt) and a truncated mutant gpI(trc) lacking transmembrane and cytosolic domains were cloned by using the PCR. Cells transfected with cDNA encoding gpI(wt) or gpI(trc) synthesized and N glycosylated the proteins. gpI(wt) accumulated in the TGN, some reached the plasmalemma, but none was secreted. In contrast, gpI(trc) was retained and probably degraded in the endoplasmic reticulum; none was found on cell surfaces, but some was secreted. The distribution of gpI(trc) was not affected by deletion of potential glycosylation sites. To locate a potential gpI-targeting sequence, cells were transfected with cDNA encoding chimeric proteins in which the ectodomain of a plasmalemmal marker, the interleukin-2 receptor (tac), was fused to different domains of gpI. A chimeric protein in which tac was fused with the transmembrane and cytoplasmic domains of gpI was targeted to the TGN. In contrast, a chimeric protein in which tac was fused only with the gpI transmembrane domain passed through the TGN and concentrated in endosomes. We conclude that gpI is targeted to the TGN as a result of a targeting sequence or patch in its cytosolic domain.
Collapse
|
291
|
Weiss ER, Hao Y, Dickerson CD, Osawa S, Shi W, Zhang L, Wong F. Altered cAMP levels in retinas from transgenic mice expressing a rhodopsin mutant. Biochem Biophys Res Commun 1995; 216:755-61. [PMID: 7488190 DOI: 10.1006/bbrc.1995.2686] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Transgenic mice expressing the rhodopsin mutant Pro347Ser (Serine 6) display retinal degeneration through apoptosis that is characteristic of the disease retinitis pigmentosa. By 5 weeks after birth, these mice have lost approximately 35% of their photoreceptor cells. Retinas from these mice showed higher levels of cAMP compared to the levels in retinas of normal mice. Our studies provide evidence that elevated cAMP is common to the apoptotic process that occurs in retinitis pigmentosa. In addition, in vitro studies demonstrate no differences in the ability of the mutant and the wild-type rhodopsin to activate transducin, the rod cell G protein, to be phosphorylated by rhodopsin kinase or to bind arrestin. Mutants of rhodopsin, including Pro347Ser, are mistargeted to the rod inner segment, raising the possibility that rhodopsin triggers apoptosis through activation of signaling pathways not normally under its control.
Collapse
|
292
|
Hu M, Hao Y, Hui Y. [Lens epithelial proliferation induced by macrophages after intraocular lens implantation in rabbits]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1995; 31:457-9. [PMID: 8762578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To approach the effect of intraocular lens implantation on the mechanism of posterior capsular opacification, the pathological changes of posterior lens capsule after intraocular lens implantation in rabbits were observed by transmission electron microscopy. The results were as follows: In the control group, 1 week after the operation and the injection of the medium of the macrophage suspension, the lens posterior capsule was covered by a layer of lens epithelium and until post-operative 6 months, the lens epithelium remained normal. In the experimental group, 1 week after the operation and the injection of the macrophage suspension into the anterior chamber, microfilaments appeared in the cytoplasm of lens epithelial cells, after 2 weeks, the lens epithelial cells produced collagen fibrils in the extracellular matrix and until postoperative 3 months, 2-3 layers of the lens epithelium proliferated in front of the posterior capsule and a large amount of collagenous fibers were formed around the cells. It is suggested that the macrophage promote the lens epithelial proliferation and the posterior capsular opacification.
Collapse
|
293
|
Yang R, Yang C, Hao Y. [Study on the reversing effect of tripiperaquine on human multidrug resistant leukemic cell line K562/A02]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1995; 17:340-2. [PMID: 8697970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
K562/A02 is a Cell line with multi-drug resistance established in our laboratory bey long term induction with adriamycin. In this paper, reversal of MDR in K562/A02 cell line by tripiperaquine is reported. The cytotoxicity and intracellular concentration of daunorubicin (DNR) in K562/A02 were measured by MTT colorimetric assay and spectrofluorimetry. The results showed that the sensitivity of K562/A02 to DNR was greatly enhanced by tripiperaquine at 10 micrograms/ml, with an 11-fold increase in cytotoxic activity. The intracellular concentration of DNR in K562/A02 was significantly increased after coincubation with 20 mumol/L tripiperaquine for 3 hours. Our results suggest that tripiperaquine might be used in clinical trial to reverse MDR.
Collapse
|
294
|
Li Y, Hao Y, Owyang C. Evidence for autoregulation of cholecystokinin secretion during diversion of bile pancreatic juice in rats. Gastroenterology 1995; 109:231-8. [PMID: 7797020 DOI: 10.1016/0016-5085(95)90289-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND & AIMS The mechanism regulating cholecystokinin (CCK) secretion during prolonged diversion of bile pancreatic juice (BPJ) is unknown. We examined the hypothesis that the decrease of plasma CCK levels after prolonged diversion of BPJ is mediated by an increase in plasma somatostatin levels evoked by hypercholecystokinemia and somatostatin in turn inhibits CCK-releasing peptide (CCK-RP) bioactivity and decreases plasma CCK levels. METHODS Pancreatic secretion, plasma CCK levels, and somatostatin levels were monitored for 7 hours after diversion of BPJ in anesthetized rats. Secretion of CCK-RP bioactivity during diversion of BPJ was examined in the presence or absence of somatostatin. RESULTS Diversion of BPJ for 2 hours caused a 13- and 2.5-fold increase in plasma CCK and somatostatin levels. The increase in somatostatin levels was blocked by the CCK antagonist L364,718. At 5 hours after diversion of BPJ, plasma CCK and somatostatin levels and luminal CCK-RP bioactivity decreased to basal levels. The decrease in plasma CCK levels was prevented by the administration of a specific somatostatin antagonist. We also showed that the stimulatory effect of the CCK-RP bioactivity was eliminated when the donor rat was pretreated with somatostatin. CONCLUSIONS Autoregulation of CCK secretion occurs during the diversion of BPJ and this is mediated by somatostatin, which inhibits the secretion of CCK-RP bioactivity and decreases plasma CCK levels.
Collapse
|
295
|
Wang J, Xiao Z, Hao Y. [Rearrangements and fusion gene of AML1 and MTG8 in acute myeloid leukemia M2b]. ZHONGHUA YI XUE ZA ZHI 1995; 75:399-402, 445. [PMID: 7553157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The t(8;21) reciprocal chromosomal translocation is frequently associated with M2b type of acute myeloid leukemia (AML). Recently, two genes, MTG8 on chromosome 8 and AML1 on chromosome 21, were found. The t(8;21) translocation resulted in rearrangements of the two genes and formation of AML1/MTG8 fusion gene. To clarify the molecular characteristics of AML-M2b, we studied 41 patients with AML-M2b. By Southern blot and hybridization, the rearrangements of AML1 and MTG8 genes were detected in 24 of 30 and 22 of 28 patients, respectively. By means of reverse transcription and polymerase chain reaction (RT-PCR), the AML1/MTG8 chimeric transcript was found in all 37 patients. In 4 patients with AML-M2b of normal karyotype, AML1/MTG8 fusion mRNA and/or rearrangements of AML1 and MTG8 genes were detected. However, among 31 patients with other types of AML, these abnormalities were found in only one patient with AML-M6. These results suggest that rearrangements of AML1, MTG8 genes and/or AML1/MTG8 fusion gene could be regarded as gene marker of AML-M2b that can be applied in the diagnosis and monitoring of therapy and minimal residual disease.
Collapse
|
296
|
Wong CS, Hao Y, Hill RP. Response of rat spinal cord to very small doses per fraction: lack of enhanced radiosensitivity. Radiother Oncol 1995; 36:44-9. [PMID: 8525024 DOI: 10.1016/0167-8140(95)01558-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Our previous work with rat spinal cord demonstrated that the linear quadratic (LQ) model based on data for large fraction sizes (alpha/beta of 2.4 Gy) failed to predict isoeffective doses between 1 and 2 Gy per fraction, and under-estimated the sparing effect of small doses per fraction given once daily. In contrast, data from mouse skin and kidney, and recent in vitro results revealed a paradoxical increase in radiosensitivity at below 1 Gy per fraction. To assess whether enhanced radiosensitivity is present in the spinal cord below 1 Gy per fraction, the rat spinal cord (C2-T2) was irradiated initially with three daily doses of 10.25 Gy (top-up doses representing 90% of tolerance), followed by graded single doses or fractionated doses in 1.5, 1.0, 0.8, 0.6 or 0.4 Gy fractions given once daily. To limit the overall treatment time to < or = 8 weeks, a small number of the 0.6- and 0.4-Gy fractions were given twice daily with an interfraction interval of 16 h. The end-point was forelimb paralysis secondary to white matter necrosis, confirmed histologically. The ED50 values, excluding the top-up doses, were 5.8, 10.6, 14.8, 15.2, 15.9 and 19.1 Gy for a single dose and doses in 1.5-, 1.0-, 0.8-, 0.6- and 0.4-Gy fractions, respectively. The data gave an alpha/beta of 2.1 Gy (95% CI, 1.4, 2.7 Gy). Pooling the data separately, the alpha/beta value was 2.3 Gy (95% CI, 0.82, 3.7 Gy) for fraction sizes > or = 1 Gy, and 1.2 Gy (95% CI, 0.16, 2.3 Gy) for the 0.8-, 0.6- and 0.4-Gy experiments.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
297
|
Hu M, Hao Y, Hui Y. [The influence of macrophage on the rates of cultured rabbit lens epithelial cell proliferation and DNA synthesis]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1995; 31:296-8. [PMID: 8745528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cell and H3-TDR liquid scintillation countings were adopted to investigate the influence of macrophage on the proliferative rate of cultured rabbit lens epithelial cells, in vitro. After 24 hours of the action of macrophage opsonic fluid on the cell culture, the rates of cell proliferation and DNA synthesis in the experimental group were higher than those of the control group (P < 0.05) and maintained so to the fifth day. It is demonstrated that the macrophage and its active factors can promote the proliferation of the lens epithelial cells, that is possibly related to the posterior capsular opacification after extracapsular cataract extraction.
Collapse
|
298
|
Hao Y. Chinese women's programs provide numerous opportunities. ASIAN FORUM NEWSLETTER : OFFICIAL ORGAN OF THE ASIAN FORUM OF PARLIAMENTARIANS ON POPULATION AND DEVELOPMENT 1995:11. [PMID: 12290526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
|
299
|
Perlman M, Claris O, Hao Y, Pandit P, Whyte H, Chipman M, Liu P. Secular changes in the outcomes to eighteen to twenty-four months of age of extremely low birth weight infants, with adjustment for changes in risk factors and severity of illness. J Pediatr 1995; 126:75-87. [PMID: 7815231 DOI: 10.1016/s0022-3476(95)70507-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES To analyze secular changes in the rates of death and of major impaired outcome in surviving outborn infants who weighted < or = 800 gm at birth and were admitted in 1980 to 1989, with adjustment for changes in risk factors and severity of illness around the time of birth; and to identify changes in these factors that might explain changes in outcomes. DESIGN Retrospective cohort study with follow-up to a minimum of 18 months of postterm age. After preliminary screening, multivariate models of association between risk/severity of illness factors and outcomes were constructed, validated, and used to adjust outcomes (death and major impairment to 18 to 24 months of age). SETTING Regional neonatal intensive care unit for referral of "outborn" infants. PATIENTS Two hundred eighty-seven consecutively admitted infants who weighted < or = 800 gm at birth (97% follow-up). RESULTS The death rate during the 1980s did not fall significantly (p adjusted for risk factors = 0.115). The major impairment rate fell (odds ratio, 0.24 (95% confidence interval, 0.10, 0.60); p = 0.002, adjusted for delivery route and respiratory failure measures), mainly because of a reduced rate of blindness, not attributable to cryotherapy. The risk factors that improved and were possibly related to the reduced impairment rate were blood pH and glucose concentration, and serum sodium concentration in the first 48 hours of life. CONCLUSIONS Despite an increasing selection for referral of less mature and more severely ill outborn babies near the "limit of viability," and despite more aggressive care, the rate of major impairment fell significantly during the 1980s. This trend was enhanced by adjustment for severity of illness. The fall was attributable to a reduced rate of blindness, and was associated with evidence of improved control of physiologic balance after birth.
Collapse
|
300
|
Yao G, Gao H, Hao Y. [Histopathological and immunohistochemical study of ovarian polyembryoma]. ZHONGHUA FU CHAN KE ZA ZHI 1995; 30:18-21. [PMID: 7538460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A case of polyembryoma which is rare in ovarian malignant germ cell tumors was reported. Microscopically, numerous and variable embryoid bodies, surrounded by embryonic hepatoid tissues, trophoblastic cells and multiple elements, were observed. The results of immunohistochemical analysis were: (1) alpha fetoprotein (AFP) was not only shown positive in yolk sac cells among the embryoid bodies, in the endoderm and in the margins of the ectodermal cells, but also in multiple elements in the mucinous matrix. (2) Hepatoid tissues reacted positively to AFP and alpha antitrypsin (AAT) as well as to hCG. (3) By using hCG and human placental lactogen (hPL) as markers it is proven that among trophoblastic cells of the tumor, not only syncytiotrophoblastic cells but also the intermediate cells and the cytotrophoblastic cells could be identified.
Collapse
|