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Biomedical subjects

Ying Han

Publications and source records attributed to Ying Han.

At least 37 records · Page 2Linked to original sources

[Trehalose loading red blood cells and freeze-drying preservation].

This study was aimed to investigate the feasibility of cryopreserving red blood cells (RBCs) by loading with trehalose and to evaluate the effect of trehalose on lyophilized RBCs. Based on the thermal properties of RBC plasma membrane, the RBCs were incubated in 0.8 mol/L trehalose solution at 37 degrees C for 7 hours, and RBCs incubated in phosphate-buffered saline were used as control. The morphology of RBCs was observed by light and scanning electron microscopy, the hemolysis rate of loaded RBCs was detected by using cyanohemoglobin kit, the intracellular trehalose levels were assayed by sulfate anthrone method, the intracellular ATP and 2, 3-DPG levels were determined by bioluminescence assay and 2, 3-DPG kit respectively, meanwhile the deformation and osmotic fragility of RBCs were measured. The results showed that the intracellular trehalose concentration was 36.56 +/- 7.95 mmol/L, the electronical microscopic images of trehalose-loaded RBCs showed the membrane integrity, the hemolysis rate in trehalose-loaded RBCs was 15.663 +/- 3.848%, while hemolysis rate in controlled RBC was 5.03 +/- 1.85% (P < 0.05). Maximum index of deformation in trehalose-loaded RBC was 0.0289 +/- 0.00738, while maximum index of deformation in control group was 0.1200 +/- 0.0121 (P < 0.05), The level of ATP in trehalose-loaded RBC was 2.67 +/- 0.54 micromol/gHb, while the level of ATP in control group was 5.22 +/- 1.10 micromol/gHb (P > 0.05). Osmotic fragility data showed that trehalose exerted osmotic protection on RBC. During loading period the level of 2, 3-DPG in trehalose-loaded RBC was maintained close to the level in control. When trehalose-loaded RBCs were lyophilized and rehydrated, the recovery rate of hemoglobin was about 46.44 +/- 4.14% and that in control was 8.33 +/- 2.34% (P < 0.001). The recovery rate of hemoglobin of trehalose-loaded RBC was higher than that of control. It is concluded that trehalose can be integrated in the membrane of RBC in lyophilization state, maintain the integrity of RBC membrane, and significantly enhance the recovery rate of hemoglobin of cryopreserved RBCs. Cryopreserving RBCs by loading with trehalose is feasible.

Blood Preservation↗

[Effects of electroacupuncture on GDNF positive cell immunoreactivity in local dermal tissue of the inflammatory pain focus in the rat of adjuvant arthritis].

OBJECTIVE: To study on the analgesic mechanism of electroacupuncture (EA) in the rat of adjuvant arthritis (AA). METHODS: Forty-eight SD rats were randomly divided into a blank control group (n = 8), an inflammatory group (n = 10), an acupoint EA group (n = 10), a non-acupoint EA group (n = 10) and a contralateral acupoint EA group (n = 10). Complete Freund's adjuvant (CFA) 50 microL were injected into the left malleolus' articular cavity in the rats except the blank control group for preparing single local adjuvant arthritis (AA) model. EA was given every other day to the acupoint EA group, the non-acupoint EA group and the contralateral acupoint EA group. The improving effects of EA at "Huantiao" (GB 30) and "Yanglingquan" (GB 34) on the dorsal flexion pain score and the swell of dorsum of hind paw were investigated, and effects of EA on Glial cell line-derived neurotrophic factor (GDNF) positive cells immunoreactivity in the inflammatory tissue of the AA rats on the 14th day after injection of adjuvant were observed with immunohistochemical technique. RESULTS: Hyperalgesia and local swell, and GDNF in the dermal and subcutaneous tissue around the inflammatory ankle joint in the inflammatory groups were significantly higher than those in the blank control group. EA on the ipsilateral and contralateral acupoints reduced the pain, promoted the recovery of swell, and decreased the positive area percentage and mean optical density of GDNF positive cells in the dermal and the subcutaneous tissues. However, the non-acupoint EA group did not have this action. CONCLUSION: EA can regulate expression of GDNF in local dermal tissue of the inflammatory focus in the AA rat, so as to exert the anti-inflammatory and analgesic effects.

Animals↗

[Long-term alteration of gamma-aminobutyric acid B receptor subunits in immature rats after recurrent febrile seizures].

OBJECTIVE: Febrile seizure (FS) is closely related to an altered transmission of gamma-aminobutyric acid (GABA). GABA exerts its effects through ionotropic receptors (GABA(AR) and GABA(CR)) and metabotropic receptors (GABA(BR)). GABA(BRs) are located at pre- and postsynaptic sites. Stimulation of postsynaptic receptors generates long-lasting inhibitory postsynaptic potentials (IPSPs) that are important for the fine-tuning of inhibitory neurotransmission and caused by an increase in K(+) conductance. At presynaptic sites, GABA(BRs) mediate a suppression on the release of neurotransmitters such as of GABA or glutamate by inhibiting voltage-sensitive Ca(2+) channels. The present study aimed to explore the long-term changes of GABA(B) receptor subunits in immature rats after recurrent febrile seizures. METHODS: Rats were randomly divided into control group and hyperthermia treatment group. The control rats (n = 64) were put into 37 degrees C water for 5 minutes. Rats with hyperthermia treatment were put into 44.8 degrees C water for 5 minutes. If a rat in hyperthermia treatment group showed seizure within 5 min, the rat was taken out of the water as soon as the seizure occurred. Water-immersion was carried out 10 times, once every 2 days. Rats showing 10 seizures (FS(10), n = 64) were studied. Rats exposed to hyperthermia for 10 times without seizure were also studied as hyperthermia-only (H, n = 64) group. Rats showing one seizure at the last time of 10 times of hyperthermia treatment were studied as one-seizure group (FS(1), n = 64). The other rats were studied for other research. The changes of GABA(B)R(1) and GABA(B)R(2) co-localization were detected by double fluorescence;the quantitative alteration of GABA(B)R(1) and GABA(B)R(2) were detected by quantitative RT-PCR; the binding of GABA(B)R(2) to GABA(B)R(1) was detected by immunoprecipitation/Western blot. RESULTS: GABA(B)R(1), GABA(B)R(2), and the binding of GABA(B)R(2) to GABA(B)R(1) decreased after the last febrile seizure in FS(10) group, the expression of GABA(B)R(1) returned to normal in later phase while GABA(B)R(2) and the binding of them did not. CONCLUSION: Recurrent FS down-regulated the expression of GABA(B)R subunits in a long term.

Age Factors↗

[Expression and clinical value of SHP-1 and c-kit in acute leukemia].

The aim of study is to investigate the expression of hematopoietic cell phosphatase (SHP-1) gene and c-kit pro-oncogene in acute leukemia (AL) and its impact on prognosis in AL. Semi-quantity reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of SHP-1 mRNA and c-kit mRNA in 60 AL patients and 33 normal controls (NC). The results showed that the positive rates of SHP-1 expression from high to low level were found orderly in complete remission group, newly diagnosed group and relapsed group, there was significance difference between each group and NC group (P < 0.05). The positive rates of c-kit expression were opposite order in each groups as compared with SHP-1. there was also significance difference between each group and NC group (P < 0.05). The positive rate of SHP-1 and c-kit expressions in AML was higher than that in ALL (P < 0.05), there was negative correlation between expressions of SHP-1 and c-kit (r = -0.502, P < 0.05); The difference between the complete remission rate in SHP-1 positive and in SHP-1 negative patients from 30 newly diagnosed AML patients was significant (P < 0.05), the same result was found between c-kit(+) complete remission and c-kit(-) complete remission. It is concluded that SHP-1 gene is a potentially anti-oncogene and inhibits the growing of tumor by negatively modulating c-kit gene. Simultaneous detection of SHP-1 and c-kit gene may act as a factor for predicting prognosis in AL.

Adolescent↗

[Advances in the studies of the clearance mechanism of transfused platelet concentrates: review].

Platelet clearance has already been studied in physiological and pathological conditions and shown its occurrence mainly in the liver and the spleen. It is still not clear what mechanisms are responsible for recognition and removal of either aged or damaged platelets by the scavenging system. So study of the clearance mechanism will be useful to prolong the survival time of platelets in vivo. And it may be related to a new strategy to store platelets. This article focuses on the advances in studies of the clearance mechanism of transfused platelet concentrates, including roles of P-selectin, GPI balpha and its receptor Mac-1 in platelet clearance, and effect of endogenous metalloproteinase in platelet clearance.

Blood Platelets↗

Successive alterations of hippocampal gamma-aminobutyric acid B receptor subunits in a rat model of febrile seizure.

Febrile seizure (FS) is a frequently encountered seizure type in childhood. Changes of brain function following FS have clinical importance. The recently identified gamma-aminobutyric acid B receptor (GABA(B)R) is a metabotropic receptor of GABA. In this study, we used a rat model of recurrent FS to investigate the changes of GABA(B)R1a and GABA(B)R2 subunits in hippocampus after recurrent FS by using Western blot, quantitative RT-PCR, double immunofluorescence, in situ hybridization and immunoprecipitation/Western blot. After treatment of hyperthermia and the presence of induced seizures once every 2 days for 10 times, GABA(B)R1a and GABA(B)R2 subunits in hippocampus were decreased after 24 h of the last treatment. The decrease of GABA(B)R1a lasted for 15 days but that of GABA(B)R2 persisted for more than 30 days. The binding of GABA(B)R1a to GABA(B)R2 in hippocampus was also decreased significantly after 24 h of the last treatment and lasted for more than 30 days. In situ hybridization showed that GABA(B)R1a mRNA was significantly decreased in dentate gyrus, and GABA(B)R2 mRNA was considerably reduced in CA3 region. In H10 and FS1 groups in which hyperthermia treatment was the same but no (H10 group) or only one seizure (FS(1) group) was induced, the decrease of GABA(B)R1a and GABA(B)R2 subunits and the reduced binding capability between GABA(B)R1a and GABA(B)R2 subunits were also detected but with less severity, and the time recovering from these abnormalities was shorter. We conclude that GABA(B)R1a and GABA(B)R2 subunits and the binding of the 2 subunits decrease in hippocampus for a relatively long period of time after recurrent FS in immature rats. These changes may result in long-lasting imbalance of excitation/inhibition function in hippocampus, and are derived from the consequences of recurrent febrile seizures.

Animals↗

Diversity of function in the isocitrate lyase enzyme superfamily: the Dianthus caryophyllus petal death protein cleaves alpha-keto and alpha-hydroxycarboxylic acids.

The work described in this paper was carried out to define the chemical function a new member of the isocitrate lyase enzyme family derived from the flowering plant Dianthus caryophyllus. This protein (Swiss-Prot entry Q05957) is synthesized in the senescent flower petals and is named the "petal death protein" or "PDP". On the basis of an analysis of the structural contexts of sequence markers common to the C-C bond lyases of the isocitrate lyase/phosphoenolpyruvate mutase superfamily, a substrate screen that employed a (2R)-malate core structure was designed. Accordingly, stereochemically defined C(2)- and C(3)-substituted malates were synthesized and tested as substrates for PDP-catalyzed cleavage of the C(2)-C(3) bond. The screen identified (2R)-ethyl, (3S)-methylmalate, and oxaloacetate [likely to bind as the hydrate, C(2)(OH)(2) gem-diol] as the most active substrates (for each, k(cat)/K(m) = 2 x 10(4) M(-)(1) s(-)(1)). In contrast to the stringent substrate specificities previously observed for the Escherichia coli isocitrate and 2-methylisocitrate lyases, the PDP tolerated hydrogen, methyl, and to a much lesser extent acetate substituents at the C(3) position (S configuration only) and hydoxyl, methyl, ethyl, propyl, and to a much lesser extent isobutyl substituents at C(2) (R configuration only). It is hypothesized that PDP functions in oxalate production in Ca(2+) sequestering and/or in carbon scavenging from alpha-hydroxycarboxylate catabolites during the biochemical transition accompanying petal senescence.

Amino Acid Sequence↗

[Alteration of hydrogen sulfide/cystathionine-beta-synthase system in rats with recurrent febrile seizures].

OBJECTIVE: To study the alteration of hydrogen sulfide (H(2)S)/ cystathionine-beta-synthase (CBS) system during recurrent febrile seizures (FS) in the hippocampus of developing rats. METHODS: The rats were randomly divided into control group (n=8) and hyperthermia-treated group (n=22). Which was subdivided into FS group (n=8) and H group(no seizure occurred, n=9) according to whether seizures occurred. The plasma level of H(2)S was detected by the spectrophotometer. The expression levels of CBS gene and protein were examined by in situ hybridization and immunohistochemistry respectively. RESULTS: The plasma levels of H(2)S were increased significantly in FS group compared with those of control group or H group. The expression levels of CBS gene and protein were enhanced in FS group compared with those of control group or H group. CONCLUSION: The expression levels of H(2)S/ CBS system were up-regulated during recurrent FS.

Animals↗

Regulation of multidrug resistance by MGr1-antigen in gastric cancer cells.

Previously, a novel protein, MGr1-Ag, was associated with tumor multidrug resistance (MDR), and the role and the underlying mechanisms of MGr1-Ag in MDR of gastric cancer cells were characterized. Initial studies using the introduction of sense or antisense vectors for MGr1-Ag resulted in the genetical up- or downregulation of MGr1-Ag in gastric cancer cells, respectively. Subsequent studies revealed the expression of MGr1-Ag, P-glycoprotein (P-gp), MDR-associated protein (MRP), Bcl-2 and Bax in gastric cancer cells via Western blot analysis. The sensitivity of gastric cancer cells to chemotherapeutic drugs was assessed using the colony-forming assay, and Adriamycin (ADM) accumulation was evaluated by flow cytometry. Further study of ADM-induced apoptosis was detected by annexin-V/propidium iodide staining. The expression level of MGr1-Ag in MDR gastric cancer cells is much higher than that in their parental cells. Overexpression of exogenous MGr1-Ag may promote the MDR phenotype of gastric cancer cells, decrease intracellular ADM accumulation and protect gastric cancer cells from ADM-induced apoptosis, whereas downregulation of MGr1-Ag had reverse effects. Western blot analysis suggested that MGr1-Ag may regulate the expression of P-gp, MRP, Bcl-2 and Bax. In conclusion, MGr1-Ag may promote MDR of gastric cancer cells via a decrease in intracellular drug accumulation and inhibition of drug-induced apoptosis.

Antibiotics, Antineoplastic↗

Reactive oxygen species in paraventricular nucleus modulates cardiac sympathetic afferent reflex in rats.

Our previous studies showed that angiotensin II (Ang II) in the paraventricular nucleus (PVN) potentiated the cardiac sympathetic afferent reflex (CSAR) in rats. This study investigated whether the reactive oxygen species (ROS) in the PVN modulated the CSAR and contributed to the effect of Ang II on the CSAR in rats. Under alpha-chloralose and urethane anesthesia, renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate were recorded in sinoaortic-denervated and cervical-vagotomized rats. The CSAR was evaluated by the RSNA response to epicardial application of bradykinin (0.04 and 0.4 microCompared with microinjection of saline into the PVN, superoxide anion scavenger, either tempol (20 nmol) or tiron (10 nmol), significantly decreased the CSAR (P < 0.05). Conversely, superoxide dismutase (SOD) inhibitor diethyldithio-carbamic acid (DETC, 10 nmol) potentiated the CSAR (P < 0.05). Microinjection of Ang II (0.3 nmol) into the PVN resulted in an enhanced CSAR (P < 0.05). The effect of Ang II on the CSAR was completely inhibited by pretreatment with either tempol or tiron (P < 0.05) but was not affected by DETC. On the other hand, either tempol or tiron decreased the RSNA (P < 0.05), but DETC increased the RSNA (P < 0.05). Ang II increased the RSNA (P < 0.05) and MAP (P < 0.05). The effect of Ang II on the RSNA and MAP was abolished by pretreatment with either tempol or tiron but was not affected by DETC. These results indicated that the ROS in the PVN modulated the CSAR and contributed to the effect of Ang II in the PVN on the CSAR.

Action Potentials↗

[Influence of nitric oxide on heme oxygenase/carbon monoxide system in hippocampus of febrile seizures rats].

OBJECTIVE: Febrile seizures (FS) are the most common type of seizure disorders. Studies have found that there have respective changes of heme oxygenase (HO)/CO system and nitric oxide synthase (NOS)/NO system during FS. The present study was to explore the influence on expression of HO-1 mRNA and protein and content of CO after recurrent FS by NOS inhibitor N(omega)-nitro-L-arginine Methyl ester (L-NAME), in order to demonstrate a regulating role in HO/CO system by NO. METHODS: Forty-eight SD rats were randomly divided into 3 equal groups: FS group, undergoing intraperitoneal injection of normal saline (NS) and then bath in 45.2 degrees C hot water for 5 minutes every other day for 10 times, FS + L-NAME group, undergoing intraperitoneal injection of NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) and then FS for 10 times, and control group, undergoing intraperitoneal injection of NS and then bath in 37.0 degrees C water. Twenty-four hours after the last bath blood was collected from the abdominal cardinal vein to measure the concentrations of plasma nitric oxide and carbon monoxide with spectrophotometer. The brains were taken out to be made into frozen slices to undergo HO-1 in situ hybridization to measure the mRNA expression of HO-1. The hippocampus was taken out to undergo Western blotting to measure the expression of HO-1 protein. RESULTS: The plasma CO concentration was higher by 94.5% in the FS group in comparison with that in the control group (P < 0.01). The plasma CO concentration of the FS + L-NAME group was higher by 63.18% than that of the control group (P < 0.05) and lower by 16.14% than in the FS group (P < 0.05). The HO-1 mRNA expression was significantly higher in the FS group than in the control group. The HO-1 mRNA expression of the in hippocampal neurons of the L-NAME was lower than that of the FS group, however, still higher than that of the control group. Western blotting showed that HO-1 protein was expressed in all 3 groups; the HO-1 protein expression of the FS group was higher by 208% than that of the control group; and the HO-1 protein expression of the FS + L-NAME group was higher by 115% than that of the control group (P < 0.01) and lower by 30.19% than that of the FS group (P < 0.01).

Animals↗

Regulation of apoptosis by the papillomavirus E6 oncogene.

Infection with human papillomaviruses is strongly associated with the development of multiple cancers including esophageal squamous cell carcinoma. The HPV E6 gene is essential for the oncogenic potential of HPV. The regulation of apoptosis by oncogene has been related to carcinogenesis closely; therefore, the modulation of E6 on cellular apoptosis has become a hot research topic recently. Inactivation of the pro-apoptotic tumor suppressor p53 by E6 is an important mechanism by which E6 promotes cell growth; it is expected that inactivation of p53 by E6 should lead to a reduction in cellular apoptosis, numerous studies showed that E6 could in fact sensitize cells to apoptosis. The molecular basis for apoptosis modulation by E6 is poorly understood. In this article, we will present an overview of observations and current understanding of molecular basis for E6-induced apoptosis.

Amino Acid Sequence↗

Hydrogen sulfide may improve the hippocampal damage induced by recurrent febrile seizures in rats.

The aim of the present study was to investigate the possible role of hydrogen sulfide (H(2)S) in the pathogenesis of recurrent febrile seizures (FS) in rats. On a rat model of recurrent FS, the ultrastructure of hippocampal neurons, the plasma level of H(2)S, the expressions of cystathionine b-synthase (CBS) and c-fos, and the development of mossy fiber sprouting (MFS) in hippocampus were examined after treatment with NaHS, a donor of H(2)S, or hydroxylamine (HA), an inhibitor of CBS. We found that the plasma level of H(2)S increased significantly, the expressions of CBS and c-fos increased markedly, and MFS was evident in hippocampus in FS group. NaHS alleviated the neuronal damage of recurrent FS rats, decreased the expression of c-fos, and inhibited MFS obviously. HA aggravated the neuronal damage of recurrent FS rats, further increased the expression of c-fos, and enhanced the mossy fiber outgrowth. The results showed that endogenous H(2)S system was involved in the development of FS. Exogenous H(2)S may exert beneficial effect on the pathogenesis of FS-related brain damage.

Animals↗

Improved preservation of human red blood cells by lyophilization.

The lyophilization of human red blood cells has important implications for blood transfusion in clinical medicine. In this study, sugars, human serum albumin, polyvinylpyrrolidone, and dimethyl sulfoxide were used as protective reagents for the lyophilization of red blood cells. Freezing temperature, shelf temperature, and the rehydration conditions were optimized. The results showed that extracellular disaccharides, especially trehalose, did not increase the recovery of hemoglobin. However, when the concentration of human serum albumin was higher than 25%, it had a considerable protective effect on the recovery of lyophilized red blood cells; the cellular hemoglobin recovery was over 70%, which was significantly higher than that in the group without human serum albumin (P<0.01). As the concentration of polyvinylpyrrolidone was increased, the extent of vitrification also increased. But when the concentration of polyvinylpyrrolidone was over 40%, the resulting concentration of free hemoglobin was over 1g/L, which was significantly higher than that with 40% (P<0.01). When lyophilization was carried out after freezing at different temperatures, the recovery of cells and hemoglobin was 70-80% and there were no significant differences among the five groups. When the shelf temperature was higher than -30 degrees C, the samples were partly collapsed, but when the shelf temperature was lower than -30 degrees C, the recovery of cells in the -40 and -45 degrees C groups was significantly higher than in the -30 and -35 degrees C groups (P<0.05). The recovery of cells and hemoglobin after lyophilization and rehydration in solutions containing low concentrations of polymers was over 80%, which is significantly higher than the other groups (P<0.01). In addition, when the temperature was higher than 25 degrees C, the concentration of free hemoglobin was significantly lower than it was at 4 degrees C (P<0.01). In conclusion, our study showed the lyophilization of red blood cells is feasible. Disaccharides have no protective effect on lyophilized cells when they are only extracellular and extensive vitrification may be not beneficial. Although the recovery of cells after lyophilization and rehydration by our method was over 70%, the ultrastructure of the cells may be compromised and some hemolysis does still exist. Further research is required.

Blood Preservation↗

Modulating effect of hydrogen sulfide on gamma-aminobutyric acid B receptor in recurrent febrile seizures in rats.

Hydrogen sulfide (H2S) is recognized as a new neuromodulator in regulating various brain functions. Some of our recent studies showed that H2S alleviates the hippocampal damage induced by recurrent febrile seizures (FS). In the present study, we used a rat model of recurrent FS and found that sodium sulfhydrate (NaHS, a donor of H2S) down-regulated the expression of c-fos and increased the expression of gamma-aminobutyric acid B receptor subunits 1 (GABA(B)R1) and 2 (GABA(B)R2). Hydroxylamine (an inhibitor of cystathionine b-synthase) up-regulated the expression of c-fos and down-regulated the expression of GABA(B)R2, but did not change the expression of GABA(B)R1. These results suggest that H2S plays a regulatory role through modulating GABA(B)R function in the pathogenesis of recurrent FS.

Animals↗

Modulation of multidrug resistance by andrographolid in a HCT-8/5-FU multidrug-resistant colorectal cancer cell line.

OBJECTIVE: To develop an HCT-8/5-FU multidrug-resistant colorectal cancer cell line and to elucidate the effect of Andrographolid (AG), an extract from Andrographis paniculate, a medicinal herb on the HCT-8/5-FU multidrug-resistant colorectal cancer cell line. METHODS: An HCT-8 colorectal cancer cell line was used and a high concentration of 5-Fluorouracid (5-FU) was introduced at the beginning to induce drug resistance, then the concentration of 5-FU was increased in gradients. Approximately 7 months later, the cells grew stably in 2.0 microg/mL of 5-FU, and the cell line was named HCT-8/5-FU multidrug-resistant colorectal cancer cell line. The resistant index of HCT-8/5-FU cells to 5-FU, adriamycin (ADM), cisplatin (DDP) was checked by MTT test, and a growth curve was drawn. The morphological changes were observed by both light and electron microscope. The function of P-170 was detected by rhodamine staining. After the application of AG and co-administration of 5-FU, ADM and DDP, the growth curves and inhibition rate as well as apoptosis rate of HCT-8/5-FU at different concentrations of AG were evaluated by MTT and flow cytometry. Rhodamine staining was used to investigate the possible mechanism involved by AG. RESULTS: The resistance index of HCT-8/5-FU to 5-FU was 16.6, and a cross-resistance to ADM and DDP was noticed. Compared with parental cells, HCT-8/5-FU cell's growth rate did not change significantly but the cell's morphology was remarkably changed as compared with parental cells. Overexpression of P-170 by HCT-8/5-FU cell was indicated through rhodamine staining. AG at a low concentration showed weak inhibitory effect on HCT-8/5-FU. However, a remarkable inhibitory and apoptosis rate was shown when AG was co-administered with 5-FU, ADM and DDP, respectively. Interestingly AG alone could not induce apoptosis and change the cell cycles. AG might affect the expression of P-170, which was indicated by rhodamine staining. CONCLUSIONS: The HCT-8/5-FU multidrug-resistant colorectal cancer cell line has been successfully developed and because it has cross-resistance to 5-FU, ADM and DDP, it might serve as an ideal multidrug resistance (MDR) model for colorectal cancer research. The mechanism of HCT-8/5-FU resistance to chemotherapeutic agents might be related to the overexpression of P-170. Low concentrations of AG alone have no significant inhibition on HCT-8/5-FU and fail to induce apoptosis and to change cell cycles. AG might act as a chemosensitizer when co-administered with 5-FU, ADM and DDP, and the mechanism of reversal modulation of multidrug resistance by AG in the HCT-8/5-FU resistant cell line might be related to its downregulation of overexpression of P-170.

Adenocarcinoma↗

Fixation stability in normal children.

Fixation stability was found to increase with increasing age (4-15 years) in normal children, but there was no directional preponderance in fixation location.

Adolescent↗