Biomedical subjects

Y Hu

Publications and source records attributed to Y Hu.

At least 199 records · Page 11Linked to original sources

PubMed2000

Hyperexpression and activation of extracellular signal-regulated kinases (ERK1/2) in atherosclerotic lesions of cholesterol-fed rabbits.

A hallmark of hyperlipidemia-induced atherosclerosis is altered gene expression that initiates cell proliferation and (de)differentiation in the intima of the arterial wall. The molecular signaling that mediates this process in vivo has yet to be identified. Extracellular signal-regulated kinases (ERKs) are thought to play a pivotal role in transmitting transmembrane signals required for cell proliferation in vitro. The present studies were designed to investigate the activity, abundance, and localization of ERK1/2 in atherosclerotic lesions of cholesterol-fed rabbits. Immunofluorescence analysis revealed abundant and heterogeneous distribution of ERK1/2, mainly localized in the cap and basal regions of atheromas. A population of ERK-enriched cells was identified as alpha-actin-positive smooth muscle cells (SMCs). ERK1 and 2 were heavily phosphorylated on tyrosyl residues and coexpressed with proliferating cell nuclear antigen in atherosclerotic lesions. ERK1/2 protein levels in protein extracts from atherosclerotic lesions were 2- to 3-fold higher than the vessels of chow-fed rabbits, and their activities were elevated 3- to 5-fold over those of the normal vessel. SMCs derived from atherosclerotic lesions had increased migratory/proliferative ability and higher ERK activity in response to LDL stimulation compared with cells from the normal vessel. Inhibition of ERK activation by PD98059, a specific inhibitor of mitogen-activated protein kinase kinases (MEK1/2), abrogated LDL-induced SMC proliferation in vitro. Taken together, our findings support the proposition that persistent activation and hyperexpression of ERK1/2 may be a critical element to initiate and perpetuate cell proliferation during the development of atherosclerosis.

Animals↗

PubMed2000

Mouse model of transplant arteriosclerosis: role of intercellular adhesion molecule-1.

Transplant-accelerated arteriosclerosis in coronary arteries is the major limitation to long-term survival of patients with heart transplantation. The pathogenesis of this disease is not fully understood. Herein, we describe a simplified model of artery allografts in the mouse that allows us to take advantage of transgenic, knockout, or mutant animals. Common carotid arteries or aortic vessels were end-to-end allografted into carotid arteries between C57BL/6J and BALB/c mice. Neointimal lesions were observed as early as 2 weeks after surgery and had progressed at 4 and 6 weeks postoperatively. The lumen of grafted arteries was significantly narrowed due to neointima hyperplasia 4 weeks after transplantation. Using this model, we studied the role of intercellular adhesion molecule-1 (ICAM-1) in the development of transplant arteriosclerosis in ICAM-1-deficient mice. Neointimal lesions of artery grafts from ICAM-1 -/- C57BL/6J to BALB/c mice were reduced up to 60% compared with wild-type controls. MAC-1 (CD11b/18)-positive cells adhering to the surface of ICAM-1 -/- artery grafts were significantly less as identified by en face immunofluorescence, and these positive cells were more abundant in intimal lesions of artery grafts in wild-type mice. Furthermore, the major cell component of neointimal lesions 4 weeks after surgery was found to be alpha-actin-positive smooth muscle cells, which were significantly reduced in lesions of ICAM-1 -/- artery grafts. Thus, this model has been proven to be useful for understanding the mechanism of transplant arteriosclerosis. Our findings demonstrate that ICAM-1 is critical in the development of allograft arteriosclerosis via mediation of leukocyte adhesion to, and infiltration into, the vessel wall.

Actins↗

PubMed2000

Ras/Rac-Dependent activation of p38 mitogen-activated protein kinases in smooth muscle cells stimulated by cyclic strain stress

p38, a subfamily of the mitogen-activated protein kinases (MAPKs), is a crucial signal transducer between a variety of extracellular stimuli and gene expression in mammalian cells. This kinase is activated in cultured cells stimulated by heat shock, osmotic stress, and proinflammatory cytokines, but a similar activation of p38 MAPKs in vascular smooth muscle cells (SMCs) stimulated by mechanical stress has yet to be studied. We studied signal pathways leading to time- and strength-dependent p38 activation in rat SMCs in response to cyclic strain stress. p38 phosphorylation in stressed SMCs showed maximal activation at 10 minutes. This activation was significantly inhibited by pretreatment of the SMCs with pertussis toxin, a G-protein antagonist, and enhanced by treatment with suramin, a growth factor receptor antagonist, but opposite effects in the activation of extracellular signal-regulated kinases stimulated by mechanical forces were found. p38 activation was markedly reduced in stressed SMCs after protein kinase C depletion. Interestingly, SMC lines stably expressing dominant-negative ras (ras N17) or rac1 (rac1 N17) almost abolished p38 phosphorylation induced by cyclic strain stress. When p38 activation was inhibited by the specific inhibitor SB 202190, SMC migration, determined in a Boyden chamber in response to stimulation with platelet-derived growth factor-BB, and SMC proliferation, stimulated by cyclic strain stress, were abrogated. Thus, we provide the first evidence that cyclic strain stress rapidly activates p38 MAPKs via activation of protein kinase C ras/rac signal pathways, suggesting that p38 MAPKs are important signal transducers mediating the mechanical stress-induced cell responses essential for SMC migration and proliferation.

Journal Article↗

PubMed2000

Grasping after a delay shifts size-scaling from absolute to relative metrics.

We carried out three experiments designed to compare the effects of relative and absolute size on manual prehension and manual estimates of perceived size. In each experiment, right-handed subjects were presented with two different-sized 3-D objects in a virtual display and were instructed to pick up or estimate the size of one of them. In Experiment 1, subjects were requested to pick up the smaller one of two virtual objects under one condition and the larger one under the other condition. In fact, the target object was identical on all trials; it was simply paired with a smaller object on some trials and a larger object on others. To provide veridical haptic feedback, a real object was positioned beneath a mirror at the same location as the virtual target object. In Experiment 2, one of the virtual objects was marked with a red dot on its top surface. From trial to trial, the marked object was paired with a larger, smaller, or same-sized object. Subjects were instructed to always pick up the marked object on each trial. In both Experiment 1 and 2, half the subjects were tested in delayed grasping with a 5-sec delay between viewing the objects and initiating the grasp, and half in real-time grasping without a delay. Using the same display of virtual objects as in Experiment 2, subjects in Experiment 3 were requested to estimate the size of the marked object using their index finger and thumb (i.e., they showed us how big the object looked to them). After estimating the target object's size, they picked it up. All subjects gave their estimates either immediately or after a delay. Recording of hand movements revealed that when subjects in Experiments 1 and 2 picked up the target object in real time, their grip aperture in flight was not significantly affected whether the object was accompanied by a larger object or a smaller one. When subjects picked up the target object after a delay, however, their grip aperture in flight was larger when the target object was accompanied by a smaller object than when it was accompanied by a larger object. A similar size-contrast effect was also observed in Experiment 3 in which subjects gave manual estimates of the perceived size of the target object. This perceptual effect was observed both when the estimates were given immediately and when they were given after a 5-sec delay. These results suggest that normal (real-time) visuomotor control relies on absolute metrics, whereas delayed grasping utilizes the same relative metrics used by conscious perception.

Hand↗

PubMed2000

A new function of BMP4: dual role for BMP4 in regulation of Sonic hedgehog expression in the mouse tooth germ.

The murine tooth development is governed by sequential and reciprocal epithelial-mesenchymal interactions. Multiple signaling molecules are expressed in the developing tooth germ and interact each other to mediate the inductive tissue interactions. Among them are Sonic hedgehog (SHH), Bone Morphogenetic Protein-2 (BMP2) and Bone Morphogenetic Protein-4 (BMP4). We have investigated the interactions between these signaling molecules during early tooth development. We found that the expression of Shh and Bmp2 is downregulated at E12.5 and E13.5 in the dental epithelium of the Msx1 mutant tooth germ where Bmp4 expression is significantly reduced in the dental mesenchyme. Inhibition of BMP4 activity by noggin resulted in repression of Shh and Bmp2 in wild-type dental epithelium. When implanted into the dental mesenchyme of Msx1 mutants, beads soaked with BMP4 protein were able to restore the expression of both Shh and Bmp2 in the Msx1 mutant epithelium. These results demonstrated that mesenchymal BMP4 represents one component of the signal acting on the epithelium to maintain Shh and Bmp2 expression. In contrast, BMP4-soaked beads repressed Shh and Bmp2 expression in the wild-type dental epithelium. TUNEL assay indicated that this suppression of gene expression by exogenous BMP4 was not the result of an increase in programmed cell death in the tooth germ. Ectopic expression of human Bmp4 to the dental mesenchyme driven by the mouse Msx1 promoter restored Shh expression in the Msx1 mutant dental epithelium but repressed Shh in the wild-type tooth germ in vivo. We further demonstrated that this regulation of Shh expression by BMP4 is conserved in the mouse developing limb bud. In addition, Shh expression was unaffected in the developing limb buds of the transgenic mice in which a constitutively active Bmpr-IB is ectopically expressed in the forelimb posterior mesenchyme and throughout the hindlimb mesenchyme, suggesting that the repression of Shh expression by BMP4 may not be mediated by BMP receptor-IB. These results provide evidence for a new function of BMP4. BMP4 can act upstream to Shh by regulating Shh expression in mouse developing tooth germ and limb bud. Taken together, our data provide insight into a new regulatory mechanism for Shh expression, and suggest that this BMP4-mediated pathway in Shh regulation may have a general implication in vertebrate organogenesis.

Animals↗

PubMed2000

Biological effects of single and repeated swimming stress in male rats: beneficial effects of glucocorticoids.

We have examined the biological effects of single (45 min at 22 degrees C) and repeated swimming stress (45 min at 22 degrees C for 7 d) using male Sprague-Dawley rats. Repeated swimming for a week resulted in a significant inhibition in total body weight (25%) as compared to control unstressed animals. There was significant increase in adrenal and kidney relative weight and decreases in relative thymus weight in repeated swimming-stressed animals as compared to control animals. Repeated swimming stress resulted in almost threefold increase in plasma corticosterone levels with concomitant dramatic decrease in total glucocorticoid receptor (GR) levels in liver, thymus, and heart as compared to control unstressed animals. Interestingly, single swimming stress resulted in a significant elevation in lipid peroxidation levels in the liver and heart. In contrast, there was no change in the lipid per oxidation levels in the liver and heart between chronic stressed and control unstressed animals. Finally, both single and repeated swimming-stress animals had almost 50% reduction in plasma triglyceride levels as compared to control unstressed animals. It is concluded that elevated plasma corticosterone levels by downregulating GR during repeated swimming stress exerts beneficial effects in rats by retarding the total body weight gain and lowering plasma triglyceride levels without affecting free-radicals-induced oxidative stress.

Adrenal Glands↗

PubMed2000

Enantioselectivity of pregnanolone-induced gamma-aminobutyric acid(A) receptor modulation and anesthesia.

This study reports the actions of enantiomer pairs of anesthetic steroids 3alpha5alphaP/ent-3alpha5alphaP and 3alpha5betaP/ent-3alpha5betaP as modulators of gamma-aminobutyric acid (GABA)(A) receptors and as anesthetics. The enantiomers of structurally related 17-carbonitrile analogs also are examined. These studies were aimed at 1) determining whether the steroid recognition site could distinguish between molecules differing in shape, but not other physical properties (enantioselectivity); 2) providing further insight into the structure-activity relationships of anesthetic steroids; and 3) determining whether modulation of GABA(A) receptor function correlates with anesthetic potency for anesthetic steroid enantiomers. Stereoselective actions of the compounds were evaluated in four different bioassays: 1) noncompetitive displacement of [(35)S]t-butylbicyclophosphorothionate from the picrotoxin site of GABA(A) receptors present in rat brain membrane preparations; 2) modulation of GABA currents in cultured rat hippocampal neurons; 3) loss of righting reflex in tadpoles; and 4) loss of righting reflex in mice. The data indicate that 5alpha-reduced steroids, but not 5beta-reduced steroids, show a high degree of enantioselectivity/enantiospecificity in their actions as modulators of GABA(A) receptors and as anesthetics. For all compounds studied, the effects on GABA(A) receptor function closely tracked with anesthetic effects. These data show that the anesthetic steroid recognition site is capable of distinguishing enantiomers, suggesting a protein-binding site of specific dimensions and shape. The results are compatible either with a structural model of the binding site that can accommodate 3alpha5alphaP, 3alpha5betaP, and ent-3alpha5betaP, but not ent-3alpha5alphaP, or with two different binding sites for steroid anesthetics.

Anesthetics↗

PubMed2000

IkappaB kinase alpha is essential for development of the mammalian cornea and conjunctiva.

PURPOSE: To determine the requirement of IkappaB kinase alpha (Ikkalpha) for differentiation of the mammalian cornea and conjunctiva. METHODS: Newborn mice or surgically removed embryonic day (E)18 to E19 fetuses of wild-type and IKK:alpha(-/-) mice were analyzed by light microscopy and electron microscopy or immunocytochemistry using anti-keratin (K)12, K4, K5, IkappaB, or nuclear factor (NF)-kappaB (p50) antibody. RESULTS: In the IKKalpha(-/-) eyes, the epithelium of the cornea and the conjunctiva consisted of poorly differentiated cells with round nuclei. K5 was much stronger in the conjunctiva of the IKKalpha(-/-) mice. Expression of K12 in the cornea and K4 in the conjunctiva was impaired in the IKKalpha(-/-) mice. IkappaB expression was low in epithelium of the cornea and conjunctiva of the wild type mice but was very strong in that of the IKKalpha(-/-) mice. During normal development of the conjunctiva, nuclear localization of p50 was seen in areas where basal undifferentiated cells give rise to differentiated cell types, marked by expression of cK4. However, in the IKK++alpha(-/-) tissues, no nuclear p50 staining was detected. CONCLUSIONS: IKKalpha is specifically required for formation of cornea and conjunctiva. This function may be exerted through an effect on NF-kappaB activity.

Animals↗

PubMed2000

Effects of carbon tetrachloride-injured hepatocytes on hepatic stellate cell activation and salvianolic acid A preventive action in vitro.

OBJECTIVE: To investigate the effects of carbon tetrachloride (CCl(4))-injured hepatocyte on hepatic stellate cell (HSC) activation, the relation between lipid peroxidation and liver fibrosis, and the action mechanisms of salvianolic acid A (SA-A), one of water soluble components extracted from radix salvia miltiorrhizae, against HSC activation and liver fibrosis. METHODS: The hepatocytes were isolated from the normal rats, incubated with SA-A at different concentrations, respectively, and vitamin E severed as control. At the same time the cells were fumigated with CCl(4) for 24h, and ALT activities in the medium were measured. After the cell medium was changed and cultured for another 24h, the medium was collected as "hepatocyte conditioned medium" (HCM) and measured for malondiadehyde (MDA) content. Then HCM was incubated with primary cultured HSC for 48h, and HSC proliferation, type I collagen gene expression and protein production were observed. RESULTS: ALT activity and MDA content in the hepatocyte medium were increased remarkably after the cell was injured. HCM could obviously promote HSC proliferation, type I collagen mRNA expression and protein production. SA-A could markedly inhibit ALT activity and MDA content in hepatocytes, and decreased collagen gene expression and protein production. CONCLUSION: The secretion from the peroxidative injured hepatocyte could stimulate HSC activation, SA-A could decrease activation by alleviation of hepatocyte peroxidation.

Alanine Transaminase↗

PubMed2000

Complete sequence and organization of Periplaneta fuliginosa densovirus genome.

The replicative form (RF) of the Periplaneta fuliginosa densovirus (PfDNV) genome was cloned and its complete nucleotide sequence was determined. The PfDNV genome is 5454 nucleotides (nt) in length with distal 201-nt long inverted terminal repeats (ITRs). The first 122 nt at the 5'-end and the terminal 122 nt at the 3'-end of both strands are palindromes with identical sequences, of which each can fold into a typical U-shaped hairpin structure. The coding regions of PfDNV genome are evenly distributed in the 5'-halves of both strands. PfDNV genome contains seven major open reading frames (ORFs), four of which on the plus DNA strand may encode non-structural (NS) proteins, while the others on the minus DNA strand may encode structural proteins. Two potential functional promoters (P3 and P97) were found within the ITRs on both strands. The ORF2 polypeptide contains a highly conserved NTP-binding domain of NS proteins of parvoviruses. The ORF5 polypeptide has significant homology to the conserved PGY region of coat proteins of parvoviruses. The ORF6 polypeptide has distinct homology to the structural polypeptides of insect parvoviruses. The organization of PfDNV genome was compared to those of other parvoviruses.

Amino Acid Sequence↗

PubMed2000

[Increased radiosensitivity of lung cancer cell lines related with the functionally replaced p14ARF gene].

OBJECTIVE: To assess the possibility that whether restored or enforced function of p14ARF could influence the radiosensitivity of lung cancer cells in vitro. METHODS: Human lung cancer cell lines with various endogenous backgrounds in INK4a, p53 and Rb genes were used as the recipients of the wild-type p14ARF gene. The expression of p14ARF mRNA and protein was detected with RT-PCR, immunohistochemistry and Western immunoblot after G418 selection. Clones expressing both p14ARF mRNA and protein were identified and selected for further experiments. By comparing with the parental and negative control cells prepared with empty vector, the effects of exogenously transfected p14ARF on cell cycle distribution, cell survival fraction and radiation-induced proportion of apoptosis were analyzed. RESULTS: The cell cycles of three wild-type p53 cell lines were arrested in G1 phase or G1 and G2-M phases. A significant decline in the proportion of S phase was observed in H460-p14ARF and A549-p14ARF cells, with decreased survival fraction and prolonged G2 delay after irradiation. We also observed in A549-p14ARF cells an increased percentage of apoptosis when radiated. CONCLUSION: The exogenously transfected wild-type p14ARF could increase the radiosensitivity of some lung cancer cells. It appears that cell cycle redistribution of cells after acquiring p14ARF may be the main explanation for the enhanced sensitivity. The increased apoptosis proportion of A549-p14ARF cells in response to radiation indicates a fortified p53 function and might partly contribute to the increased sensitization.

Carcinoma, Non-Small-Cell Lung↗

PubMed2000

[Wetland ecosystems formation and its protection in Yellow River Delta].

Site investigation, satellite photo analysis and historic material analysis show that the vast neonatal wetlands in Yellow River Delta were created by high concentration sediment of the river and the land-sea evolution. Affected by the regional climate, landform, geological deposition, soil, vegetation and their interactions, the wetlands covered 4.5 x 10(5) hm2, 6.84 x 10(4) hm2 of which were artificial wetlands. The wetland ecosystems changed with the waving of the Yellow River Mouth and the land development in the Delta area. From ocean to land, the sublittoral aquatic wetland, eulittoral wetland, eplittoral salt wetland, bulrush-quitch wetland, meadow wetland and land agroecosystem were developed. The wetland ecosystems had abundant biological resources, including 1524 wild animals, 300 birds and 1040 fishes, which were changed recently by the oil development and affected by the interruption of Yellow River. Wetland protection should be strengthened in resources utilization.

Conservation of Natural Resources↗

PubMed2000

Safety and immunogenicity of lyophilized, live attenuated hepatitis A vaccine in non-human primate model.

OBJECTIVE: To evaluate the safety and immunogenicity of lyophilized, live attenuated hepatitis A vaccine (H2 strain) in rhesus monkeys. METHODS: Nine adult rhesus monkeys were used as experimental animals. The rhesus monkeys without anti-HAV were divided randomly into the aqueous vaccination group (4 rhesus monkeys), the lyophilized vaccination group (3 rhesus monkeys), and the control group (2 rhesus monkeys). Monkeys were inoculated by intramuscular injection, with control monkeys being inoculated with Minimum Essential Medium Eagle (MEM). Following vaccination, the monkeys were observed for the development of diarrhoea and other adverse side-effects, such as changes in appetite, frequency of defaecation and stool consistency for seven days. At the weeks 2, 3, 4, 6, 8, 10 and 12 positnoculation, the peripheral blood was collected from all animals and assayed for anti-HAV and alanine aminotransferase (ALT) and aspartate aminotransferase (AST), at weeks 0, 4 and 8 postinocuation, needle-biopsy specimens were taken at weeks 0, 4, 8 and 12, all monkeys were sacrificed and tissue samples were taken from liver, lung, heart, kidney and brain for pathological examination at week 12. RESULTS: Animals were immunized with a dose of 7.0 logTCID50/ml which is stable after freeze-drying. During the 12-week observation, no animals showed abnormal elevations of liver enzymes (ALT and AST) and no change in appetite or activity. Two monkeys (one in the aqueous group and the other in lyophilized group) showed possible lesions at week 8. The lyophilized vaccine, in addition to eliciting an anti-HAV IgG response similar to aqueous vaccine (P > 0.05), also showed IgM anti-HAV response at week 2 which was not observed with aqueous vaccine. CONCLUSIONS: These results demonstrate that lyophilized, live hepatitis A vaccine is safe and highly immunogenic in primates, supporting its further evaluation in human clinical studies.

Animals↗

PubMed2000

[The association between A1166-->C of angiotensin II type 1 receptor gene and pregnancy induced hypertension].

OBJECTIVE: To determine the distribution of gene type of A1166 polymorphism site of the angiotensin II type 1 receptor gene (AT1RG) and whether it might be implicated in pregnancy induced hypertension (PIH) woman. METHODS: We used polymerase chain reaction (PCR), restriction enzyme analysis and electrophoresis for this study. RESULTS: 1. The gene types of A1166 polymorphism site of AT1R gene on normal control and PIH and essential hypertension subjects were in accordance with Hardy-Weinberg laws. 2. The C allele frequencies of AT1R gene (A1166-->C) in control, PIH, and essential hypertension subjects was 3.7%, 11.4%, and 9.4%, respectively. 3. The frequency of variants(AC, CC) of AT1R gene A1166 polymorphism site in PIH (20.5%) was significantly higher than that of control subjects (7.4%). 4. The gene type of variants (AC, CC) and C allele frequency of AT1R gene A1166 polymorphism site in essential hypertension (18.8%, 9.4%, respectively) was higher than those of control subjects. There is no statistical difference in A1166-->C variants between PIH and essential hypertension. CONCLUSIONS: 1. The variants(A-->C) of 1166 polymorphism site of AT1RG predisposes increased risk of PIH. 2. The PIH patients are at the risk of suffering from essential hypertension.

Adult↗

PubMed2000

[Prognostic value of serum CA125 level in patients with advanced non-small cell lung cancer].

OBJECTIVE: To judge the prognostic value of serum CA125 level in patients with advanced non-small cell lung cancer. METHODS: Sixty-six untreated patients with advanced non-small cell lung cancer (NSCLC) confirmed histologically were studied. They received two to four cycles of chemotherapy, some of them combined with radiotherapy. All these patients were assayed for serum CA125 before treatment. The cut-off value of serum CA125 level was 35 U/ml. RESULTS: Increased serum CA125 levels were observed in 24 out of 66 patients (36.4%). Patients with increased serum CA125 levels had an average survival rate of 12.5% at 1 year and 0 at 2 years, whereas that of patients with normal serum CA125 levels was of 57.1% at 1 years, 14.3% at 2 years and 7.1% at 3 years. Cox proportion hazard multivariate analysis showed that the prognosis of patients was related to serum CA125 levels (P = 0.000) and effects of treatment (P = 0.046). CONCLUSION: CA125 can be used as an independent prognostic parameter in advanced NSCLC.

Adult↗

PubMed2000

[The value of STIR pulse sequence MR imaging in patients with pulmonary carcinoma].

OBJECTIVE: To evaluate the value of short TI inversion-recovery (STIR) MR imaging technique in diagnosing pulmonary carcinoma. METHODS: One hundred and eight patients with pathologically confirmed pulmonary carcinoma were examined by STIR pulse sequence and the results were compared with these by SE pulse sequence. RESULTS: STIR MR imaging was superior to conventional SE pulse sequences in significantly increasing the detection rate of lesions, improving images along the edge of the lesion, tumor invasion to adjacent structures, and demonstrating lymph node enlargement. CONCLUSION: STIR, with its sensitivity, is particularly useful to reveal metastatic lymph nodes and invasion to the pleura and chest wall.

Adult↗

PubMed2000

[Studies on vaccination schedule of inactivated hepatitis A vaccine].

OBJECTIVE: To evaluate three vaccination schedules of inactivated hepatitis A vaccine in rhesus monkeys (Macaca Mulatta). METHODS: Seventeen rhesus monkeys were divided randomly into four groups. The first group of five monkeys was immunized with vaccination schedule 1 (one immunization at week 0); The second group of five monkeys was immunized with vaccination schedule 2 (first injection at week 0, and booster one at week 4); the third group of five monkeys was immunized with vaccination schedule 3 (first injection at week 0, and booster one at week 24); and the fourth group of two monkeys with MEM as control. Rhesus monkeys were inoculated by intramuscular injections to detect the ALT (alanine aminotransferase), liver pathology and anti-HAV at different time. RESULTS: During the 52-week observation, no abnormal elevation of ALT or liver pathology appeared. The IgG response for vaccination schedule 1 reached the highest level (13 219 mIU/ml), and decreased gradually to 2 056 mIU/ml at week 52. After booster immunization at week 4, the IgG response for vaccination schedule 2 was 13 863 mIU/ml at week 12, and decreased to 6 285 mIU/ml. The highest level of IgG (40 638 mIU/ml) for vaccination schedule 3 appeared at week 28 after booster injection at week 24. Further more, at week 52 the IgG level for vaccination schedule 3 was also the highest among the three vaccination schedules. CONCLUSIONS: The inactivated hepatitis A vaccine is safe and well immunogenic. The vaccination schedule 3 showed the best immune response among the three vaccination schedules.

Adult↗

PubMed2000

[Detection of remnants after removal of medullary thyroid carcinoma].

OBJECTIVE: To assess whether calcium stimulation test or somatostain-receptor (SS-R) imaging could early detect remnants after removal of medullary thyroid carcinoma (MTC). METHODS: Calcitonin stimulation (calcium element 3 mg/kg weight, i.v. 10 min), carcino-embryonic antigen (CEA), gastrin (GST) and vasoactive intestinal peptide (VIP) were tested in 14 patients with postoperative MTC. SS-R imaging was used to localize the remnants after removal of MTC in patients with elevated calcitonin. RESULTS: Calcitonin stimulation test showed that the peak value of serum calcitonin was elevated in all patients, of whom 7 had the elevated vatue of basic calcitonin and peak calcitonin. In the 7 patients, SS-R imaging showed normal CEA, GST and VIP. CONCLUSIONS: It is necessary for patients after removal of MTC to perform calcitonin stimulation test for detecting remnants early. SS-R imaging may be useful for localizing remnants and metastatic foci. CEA, GST and VIP are not significant in monitoring MTC after operation.

Adult↗