Biomedical subjects

R He

Publications and source records attributed to R He.

At least 37 records · Page 2Linked to original sources

PubMed1998

Linkage analysis of the genetic markers of the candidate genes with non-insulin dependent diabetes mellitus in Chinese families.

OBJECTIVE: To explore the relationship between the genetic markers of the candidate genes (insulin receptor, glucose transporter 2 and glucokinase) and non-insulin dependent diabetes mellitus (NIDDM) in Chinese pedigrees. METHODS: Genomic DNA of 87 members in 12 Chinese NIDDM pedigrees was amplified using PCR technique. Denaturing polyacrylamide gel electrophoresis was applied to detect short tandem repeat polymorphisms. The linkage program was used under the models of autosomal dominant and recessive. The individuals with impaired glucose tolerance (IGT) of age < or = 45 and age > 45 were counted as affected and unknown status respectively. RESULTS: Linkage of insulin receptor gene and NIDDM was strongly and significantly rejected with total LOD score of-infinity (theta = 0.000). Linkage analysis of glucose transporter 2 gave the result with total LOD score of 2.646 (theta = 0.000) in 4 pedigrees. Linkage of glucokinase and NIDDM was of significance with total LOD score reaching 3.150 in the integration of 6 pedigrees. CONCLUSIONS: Mutations in or near the insulin receptor gene are unlikely to be the major cause of inherited predisposition to NIDDM in Chinese pedigrees that are related in this study, not excluding the principal role in the other Chinese or populations, while the mutations/variations near or at the glucose transporter 2 gene locus might be something of the cause, which needs more data to be ascertained, of familial NIDDM in Chinese pedigrees. However, the variations in or near the glucokinase gene might play a dominant role in the development of NIDDM in some Chinese and represent a subgroup of common NIDDM.

Adult↗

PubMed1997

Kinetics of selenium incorporation into tissues of female mallard ducks.

Selenium is essential for both mammalian and avian species, although its metabolism in birds has been less thoroughly studied. Little information has been available on the kinetics of selenium in birds, especially as it relates to the teratogenicity seen in waterfowl consuming excessive amounts. This study describes the pharmacokinetics of small amounts of 75Se as selenious acid injected into female mallard ducks. Labeled selenium was injected into a wing vein of restrained animals and tissues taken at five different time points up to 24 h post-injection. Selenium levels as percent of injected dose were determined in liver, kidney, heart, lung, adrenals, thyroid, spleen, pancreas, ovaries, intestine, muscle and plasma. Estimates of kinetic parameters (uptake and elimination rates, time of maximum concentration and maximum concentration) were obtained with a non-linear kinetics computer program (PCNONLIN, SCI Software, Lexington, KY). Results showed four basic patterns of distribution, uptake and elimination. Visceral tissues exhibited a triphasic pattern with a rapid rise, a decline followed by a distinctive increase in levels between the last two time points. Brain uptake was continuous over the 24 h. Plasma rose rapidly and then declined to a constant level. The ovaries as a tissue of interest relating to the teratogenic effects of selenium showed the greatest relative increase at 24 h, suggesting kinetic mechanisms consistent with a pathway that might lead to accumulation of toxic levels and teratogenic effects during embryo development.

Animals↗

PubMed1997

Effect of thiols on fructosamine assay.

Fresh human serum, gGAPDH and beta-mercaptoethanol were used to examine the effect of thiols on fructosamine assay. The kinetics of the reaction with both fresh human serum and gGAPDH displayed biphasic behaviour (fast and slow). When the thiols were modified with IAA, the kinetics only demonstrated the slow phase. Since the absorbance increase in the interval from 9 to 10 min was used in the fructosamine assay of glycated human serum we studied the effect of thiols on that measurement. In the case of gGAPDH, the value was approximately one-half of the original after thiol modification, suggesting thiol interference. Nevertheless, gGAPDH may contain a fructosamine structure. beta-Mercaptoethanol itself gave a strong positive result in the fructosamine assay. Hence, thiol groups on glycated proteins should be modified before doing a fructosamine assay because of their substantial interference.

Blood↗

PubMed1997

A synthetic lipopolysaccharide-binding peptide based on the neutrophil-derived protein CAP37 prevents endotoxin-induced responses in conscious rats.

The lipid A component of lipopolysaccharide (LPS) derived from Escherichia coli has been implicated as a significant mediator in the development of circulatory and metabolic dysfunction and lethality associated with sepsis. A synthetic peptide corresponding to amino acid residues 20 through 44 of the neutrophil-derived 37-kDa cationic antimicrobial protein (CAP37 P(20-44)) possesses lipid A binding characteristics which may be useful in attenuating in vivo responses induced during circumstances of endotoxemia, including sepsis. The E. coli LPS to be used in the in vivo study was shown to be attenuated by CAP37 P(20-44) in a dose-dependent manner in the in vitro reaction with Limulus amoebocyte lysate. Intravenous infusion of CAP37 P(20-44) (1.5 or 3.0 mg/kg of body weight) with E. coli LPS (250 microg/kg over 30 min) into conscious, unrestrained rats prevented LPS-induced hyperdynamic and hypodynamic circulatory shock, hyperlactacidemia, and leukopenia in a dose-related fashion. CAP37 P(20-44) (0.2, 1.0, and 5.0 mg/kg) administered intravenously to conscious, actinomycin D-sensitized rats following a lethal dose of LPS neutralized LPS toxicity, resulting in dose-dependent 7-day survival rates of 30, 50, and 80%, respectively. CAP37 P(20-44) (5.0 mg/kg) significantly inhibited the endotoxin-induced increase in circulating tumor necrosis factor alpha in sensitized rats. These data demonstrate that CAP37 P(20-44) has the capacity to abolish in vivo biological responses to LPS that are relevant to human sepsis and to significantly neutralize the toxicity of circulating E. coli LPS.

Amino Acid Sequence↗

PubMed1997

[Insulin receptors in diabetes mellitus].

We described the clinical significance of the measurement of insulin receptors and the mechanism of non-insulin dependent diabetes mellitus (NIDDM). Changes in insulin receptor (IR) of red blood cells in 47 patients with NIDDM were compared with those of 28 normal controls. The levels of high and low-affinity IR in the 47 patients with NIDDM were lower than those of normal controls and were prominent in untreated new NIDDM patients. Hyperinsulinemia was not found in these patients, indicating that the low IR is a primary defect not caused by the "down regulation" mechanism. In the IDDM patients the levels of high and low-affinity IR were higher than those of the normal controls, but decreased markedly after insulin therapy, indicating that the "up regulation" is attributable to the high IR levels, other than the primary IR defect.

Adolescent↗

PubMed1997

[nm23 expression and its correlation with lung metastasis in human salivary adenoid cystic carcinoma].

The nm23 gene products, nucleoside diphosphate kinase (NDPK), expression in salivary adenoid cystic carcinoma (ACC) was evaluted by using LSAB immunohistochemical method. Of 25 cases tested, 16 (64.0%) showed positive staining, in which, higher incidence of positive staining was found in ACC without lung metastasis (88.2%, 15/17) than in that with lung metastasis (12.5%, 1/8; P < 0.01). Expression of NDPK/nm23 was correlated with the P-TNM pattern (P < 0.05), otherwise it was not correlated with pathologic types (P > 0.05). The result suggest that the nm23/NDPK may play a role in suppressing the metastatic potential in ACC.

Carcinoma, Adenoid Cystic↗

PubMed1997

[Experimental study on antitumor effect in vitro of modified DNL of oral squamous cell carcinoma with TNF-alpha gene].

The gene coding for TNF-alpha was introduced into DNL of human oral squamous carcinoma by retroviral-mediated gene transduction, and experiments proved that the gene had been introduced into the DNL and the DNL could secrete TNF-alpha of high activity with PCR analysis, bioactivity analysis of TNF-alpha, selection test in G418. Cytotoxicity of gene-transduced and nontransduced DNL to Tca8113 cell was compared with MTT method. The result showed that cytotoxicity of the former was higher than that of the latter.

Carcinoma, Squamous Cell↗

PubMed1997

[Molecular biology studies on metalloproteinase and tissue inhibitor of metalloproteinase expression in salivary adenoid cystic carcinoma].

In order to research the relation between metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) and metastasis of salivary adenoid cystic carcinoma (ACC). We use dot blotting to analyse the expression of MMP-2, MMP-9 and TIMP-2 in ACC-2, a cell line of ACC in palate and ACC-M, a high lung metastasis clone which cloned from ACC-2. The result showed the expression of MMP-2 and MMP-9 were higher in ACC-M than that in ACC-2, but the expression of TIMP-2 were higher in ACC-2 than that in ACC-M This suggest MMP-2 and MMP-9 can promote ACC metastasis, TIMP-2 can suppress ACC metastasis. MMP and TIMP maybe a key mechanism of ACC metastasis.

Carcinoma, Adenoid Cystic↗

PubMed1997

[Role of type IV collagene and type IV collagenase in the invasion and metastasis of salivary adenoid cystic carcinoma].

Using immunohistochemical ABC method, the authors studied the distribution of type IV collagen and type IV collagenase in 25 cases ACC. The result showed type IV collagen was found in vascular and epithelial basement membrance, and in partly cyst of sieve-like and tubular pattern, and in cytoplasm of tumor cell. Type IV collagenase was detected in membrance and cytoplasm of tumor cell. Expression of type IV collagen and type IV collagenase were correlated with pathologic type, TNM stage and metastasis. Much positive staining of type IV collagen was found in sieve-tubular pattern, early stage of TNM and without metastasis, but much positive staining of type IV collagenase was found in solid pattern, later stage of TNM and metastasis. The result suggested that the loss of type IV collagen and over-expression of type IV collagenase may be markers of malignance of ACC.

Biomarkers, Tumor↗

PubMed1997

[Effects of SAD on cytogenetics of mouse embryonic cells and its embryo development].

We report here that SAD may not only suppress transcription activity of rRNA genes, but also increase SCE frequency of mouse embryonic cells, leading to bloching of the embryo development and fetal death, and finally significant decrease of birth percentage of the new born offsprings. Ata concentration of SAD in 10(-5)mol/L, the transcription activity of rRNA genes was decreased to 15% of the normal level, and the SCE frequency was increased doubly, leading to that the birth percentage was decreased to 50% of normal one. When SAD concentration of 10(-3)mol/L was used the transcription activity of rRNA genes was completely suppressed and SCE frequency was increased to as 4.8 times high as normal, leading to that the birth percentage dropped to 4% from 100%. Our results indicates that both the cytogenetic effects and the inhibition of the embryonic cells are directly proportional to the SAD concentration used. The relationship between the change of both the rRNA gene transcription and SCE frequency and the degree of embryo development are also discussed preliminarily.

Aldehydes↗

PubMed1996

The central distribution of adrenomedullin and its effects on blood pressure and heart rate in rats.

The present study was designed to make certain whether there exists adrenomedullin (ADM) in the rat central nervous system and evaluated the hemodynamic actions of intracerebroventricular administration (ICVA) of human ADM[13-52]. By immunohistochemistry (ABC method). We found that there was a discrete localization of ADM-positive immunoreactivity in the rat central system including cerebral cortex, paraventricular tissues, hypothalamus, cerebella cortex, mesencephalon and medulla oblongata. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, rat ADM mRNA was found to be expressed in rat brain. These above results of immunohistochemistry and RT-PCR suggest that ADM exists in the rat brain. We also found that centrally administered ADM[13-52] in a dose of 0.4 to 3.2 nmol/kg provoked marked, prolonged and dose-dependent increases in mean arterial blood pressure (MABP) and heart rate (HR). To clarify the mechanisms of the hemodynamic changes induced by centrally administered ADM [13-52], the effect of centrally administered ADM[13-52] on renal sympathetic nerve activity (RSNA) was studied. The result showed that centrally administered ADM [13-52] (1.6 nmol/kg) provoked a marked increase in RSNA, therefore, the increases in MABP and HR induced by centrally administered ADM [13-52] might be due to the stimulation of central sympathetic mechanism. In addition, we also compared the relationship of activity and structure among the different fragments of ADM. In conclusion, ADM exists in the rat brain, and it may play an important role in the central control of cardiovascular system.

Adrenomedullin↗

PubMed1996

[Observation of proliferative capacity of rat salivary gland cells].

Proliferative potentiality of adult rat salivary gland cells was studied by means of bromodeoxyuridine (BrdU) labeling in different time and ABC immunohistochemistry. The labeling rate of intercalated cells in different time after BrdU injection manifest the character of stem cell which is concordant with the theory of semipluripotential bicellular reserve cell suggested by Eversole and Batsakis. This initial labeling rate of intercalated cell is very low and it rises very rapidly to 78 times within 5 days. On the other hand, it also goes down very fast. We proved that the acinar cells and striated cells have the capacity of proliferation which is not so high as intercalated cells for self renewal that can complete the theory of semipluripotential bicellular reserve cell and is beneficial to explain why there is a variety of salivary gland neoplasms.

Animals↗

PubMed1996

[The selection of highly lung metastatic salivary adenoid cystic carcinoma clone].

After 5 times repeated selection in vivo, combined with cloning technique in vitro and analysing of platelet aggregation activity, we had selected a highly lung metastatic salivary adenoid cystic carcinoma clone M-5clone24 (Acc-M). Compared with Acc-2, its metastatic rate was 96% vs. 18%; the weight of metastatic lung was 0.88 g vs. 0.31 g. The metastatic rate and the weight of metastatic lung positively correlated with platelet aggregation activity. The aggregation activity might be used as a useful parameter to assess Acc metastasis potential.

Animals↗

PubMed1996

[Observations of cellular differentiation behaviour in adenoid cystic carcinoma of human salivary gland in vitro].

The celluar differentiation behaviour of adenoid cystic carcinoma (ACC) of salivary gland was investigated in vitro with immunohistochemistry. The results showed that the cells of ACC-2 and ACC-3 cell lines can express some marker proteins in vitro including S-100 protein, actin, myosin which is characterized as a feature of myoepithelial cells. When differentiation inducer, dB-cAMP, was added to the monolayer cells cultured in dishes, the marker protein expression increased and the CEA changed to positive. The cellular differetiation behaviour of ACC cells is related to the proliferate speed of cells. Some cells manifested finger ring-like when the culture condition was changed, it means that these cells have the secretory function. If the ACC cells were suspended singly in collagen gels which performed as an extracellular matrix they grew and formed the tubule-like structure. The results will help us to understand the histogenesis of ACC, the source of myoepithelial cells in ACC and the variety of histological structures of ACC.

Actins↗

PubMed1996

[Protective effect of angiotensin coverting enzyme inhibitor on renal function in normotensive non-insulin dependent diabetes mellitus patients with early diabetic nephropathy and microalbuminuria].

Fourty six cases of non-insulin dependent diabetes mellitus (NIDDM) with normotension and microalbuminuria (< 30 mg/24 h) were divided into groups A and B, and observed for about 2 years. Only group A was treated with perindopril 2 mg a day. We found that 2 years later glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and filtration fraction (FF) in the two groups decreased markedly, but GFR and FF decreased more markedly in group B than in group A. Meanwhile, in group A urinary albumin excretion rate (UAER) and insulin sensitivity index (SI) decreased significantly and blood pressure was stable, but in group B UAER and blood pressure elevated significantly and SI was only slightly ameliorated (P > 0.05). The levels of serum triglycerides and cholesterol were not markedly different between the two groups during the 2 years. These results indicate that ACEI may play a role in protecting the renal function in diabetic nephropathy, reduce the risk factors of atherosclerosis and improve SI. It is beneficial to retard the development of diabetic nephropathy and to protect in renal function with small dose of ACEI.

Adult↗

PubMed1995

Extracellular epitopes of platelet glycoprotein Ib alpha reactive with serum antibodies from patients with chronic idiopathic thrombocytopenic purpura.

Glycoproteins (GPs) IIb/IIIa and Ib/IX are principal targets of autoantibodies (autoAbs) in idiopathic thrombocytopenic purpura (ITP). Platelet-associated Abs against GPIIb/IIIa primarily recognize discontinuous or nonlinear epitopes (Fujisawa et al, Blood 81:1284, 1993). This study focused on whether Abs against the extracellular domain of GPIb/IX might react with short linear amino acid (aa) sequences of GPIb alpha. Complementary DNAs (cDNAs) coding for two overlapping fragments of GPIb alpha were amplified, cloned into pFLAG.2 plasmids, and expressed in Escherichia coli DH5 alpha competent cells as FLAG fusion proteins, which were purified by anti-FLAG immunoaffinity chromatography. Of 16 selected ITP sera containing anti-GPIb/IX, 6 reacted in microtiter radioimmunoassays (RIAs) with recombinant protein fragment 2 (aas 240 to 485); 1 also with fragment 1 (aas 1 to 247). When synthetic peptides corresponding to 4 segments of fragment 2 with high antigenic indices (P1 to P4) were used as targets in RIAs, all 6 sera reacted with P2 (aas 326 to 346); 1 also reacted with P4 (aas 389 to 412). P2 was shown to be present on the surface of intact platelets by adsorption studies, and anti-P2 was detected in direct eluates of platelets from ITP patients. Glycocalicin in solution effectively competed with immobilized P2 for anti-P2; P2 in solution was a less effective competitor. Epitope scanning with a panel of synthetic 15-mer peptides localized the P2 epitope to the sequence, TKEQTTFPP. Epitope definition may offer insight into the pathophysiology of and more specific treatments for ITP.

Amino Acid Sequence↗

PubMed1995

Antibody-enhanced binding of dengue-2 virus to human platelets.

The mechanisms underlying severe thrombocytopenia in dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) are not completely understood. We present here the first evidence that dengue type 2 virus binds to human platelets only in the presence of virus-specific antibody, supporting a role for immune-mediated clearance of platelets in the pathogenesis of thrombocytopenia in DHF/DSS. Antibody-enhanced binding of virus of platelets was also demonstrated with a panel of eight murine monoclonal antibodies specific for the dengue E protein. The degree of binding was dependent on the antibody used but not on the antibody IgG subclass, indicating that factors other than the platelet Fc receptor are involved in binding of virus-antibody complexes to the platelet surface. Confirmation that antibody-dependent virus binding to platelets is not primarily mediated by the platelet Fc receptor was obtained by demonstrating good binding even when platelets were pretreated with the Fc gamma RII-specific antibody IV.3.

Animals↗

PubMed1995

Isolation of a gene encoding a human reduced folate carrier (RFC1) and analysis of its expression in transport-deficient, methotrexate-resistant human breast cancer cells.

Our laboratory has previously reported the isolation of a murine cDNA which restores reduced folate carrier (RFC) activity and methotrexate (MTX) sensitivity to a MTX-resistant, transport-deficient human breast cancer cell line (MTXR ZR-75-1) (K. H. Dixon et al., J. Biol. Chem., 269: 17-20, 1994). Using this murine cDNA as a probe, we have isolated two homologous overlapping partial cDNAs from a human testis cDNA library. In addition, using human cDNA as a probe, we have isolated a 20-kb human genomic fragment which contains RFC coding regions. Analysis of the nucleotide sequence of these clones revealed that the human RFC gene, RFC1, is approximately 65% homologous to the murine and hamster genes. Using a human genomic P1 plasmid clone containing RFC1, we mapped the location of RFC1 by fluorescence in situ hybridization to the end of the long arm of chromosome 21 (21q22.2-q22.3). Fluorescence in situ hybridization analysis also showed that two copies of RFC1 were present in MTXR ZR-75-1 cells, and showed no evidence of rearrangement of this gene. Northern blot analysis of MTXR ZR-75-1 cells demonstrated a marked decrease in the level of the 3-kb RFC1 transcript relative to the parental cell line, and Western blot analysis using a polyclonal antibody raised against a peptide generated from the RFC1 sequence showed decreased expression of an approximately M(r) 56,000 protein in MTXR ZR-75-1 cells. Finally, MTXR ZR-75-1 cells transfected with an RFC1 gene showed increased MTX uptake, which was more sensitive to competition by folinic acid than by folic acid. Therefore, decreased RFC1 expression appears to be the molecular mechanism of decreased MTX uptake in this MTX-resistant cell line.

Amino Acid Sequence↗