[Placental expression of epidermal growth factor receptor in pregnancy induced hypertension]

OBJECTIVE

To clarify the expression of epidermal growth factor receptor (EGFR) in placenta from women with pregnancy induced hypertension (PIH).

METHODS

EGFR of placenta was determined by immunohistological method and compared between normal pregnancies (34 cases) and pregnancies accompanied by PIH (30 cases).

RESULTS

Positive immunostain of EGFR was located on cytoplasm, and membrane of syncytiotrophoblast and a small part of cytotrophoblast. Compared with that of normal pregnancy, the expression of EGFR in placenta from pregnancies complicated with PIH decreased significantly (P < 0.05). No significant differences of EGFR expression in placenta were found among women with mild, moderate and severe PIH (P > 0.5). No significant correlation was found between expression of EGFR and neonatal birthweight, placental weight (P > 0.01, for both).

CONCLUSION

Decreased expression of placental EGFR was found in women with PIH, and that may play a role in the pathogenesis of PIH.

The transmembrane domain of syntaxin 1A is critical for cytoplasmic domain protein-protein interactions

Assembly of the plasma membrane proteins syntaxin 1A and SNAP-25 with the vesicle protein synaptobrevin is a critical step in neuronal exocytosis. Syntaxin is anchored to the inner face of presynaptic plasma membrane via a single C-terminal membrane-spanning domain. Here we report that this transmembrane domain plays a critical role in a wide range of syntaxin protein-protein interactions. Truncations or deletions of the membrane-spanning domain reduce synaptotagmin, alpha/beta-SNAP, and synaptobrevin binding. In contrast, deletion of the transmembrane domain potentiates SNAP-25 and rbSec1A/nsec-1/munc18 binding. Normal partner protein binding activity of the isolated cytoplasmic domain could be "rescued" by fusion to the transmembrane segments of synaptobrevin and to a lesser extent, synaptotagmin. However, efficient rescue was not achieved by replacing deleted transmembrane segments with corresponding lengths of other hydrophobic amino acids. Mutations reported to diminish the dimerization of the transmembrane domain of syntaxin did not impair the interaction of full-length syntaxin with other proteins. Finally, we observed that membrane insertion and wild-type interactions with interacting proteins are not correlated. We conclude that the transmembrane domain, via a length-dependent and sequence-specific mechanism, affects the ability of the cytoplasmic domain to engage other proteins.

Heterogeneic distribution of thymidine phosphorylase between primary tumors and metastatic lesions of human pancreatic ductal carcinoma: implications for the efficacy of chemotherapy with 5-FU or its derivatives

PURPOSE

It has been suggested that the expression of thymidine phosphorylase (TdRPase) correlates with the malignant potential of various cancers, but its involvement in human invasive ductal carcinoma (IDC) of the pancreas has not been reported. In the present study, the distribution and clinical significance of TdRPase in IDCs and benign diseases of the pancreas were assessed, especially in relation to the efficacy of chemotherapy with 5-FU or its derivatives.

METHOD

The expression of TdRPase in 148 specimens of pancreatic IDCs (66 primary lesions, 46 nodal lesions and 36 distant metastases from 126 patients) and in 24 specimens of benign diseases (4 cystadenomas, 3 hyperplasias, and 17 chronic pancreatitises) was examined by immunohistochemical staining with anti-TdRPase monoclonal antibody and evaluated in terms of three grades of immunoreactivity: negative 0, low 1, or high 2.

RESULTS

Positive TdRPase staining (low and high immunoreactivity) was detected in 71% (47/66) of the primary lesions, in 46% (21/46) of the involved nodes, in 53% (19/36) of various lesions of distant metastasis, and in 37% (9/24) of the benign diseases. The staining intensity was significantly higher in the IDC tissues than in the benign disease tissues, and significantly lower in the metastatic lesions than in the primary lesions. TdRPase reactivity did not correlate with the survival rate in both resectable and unresectable IDCs. In patients with both primary tumor and nodal involvement, however, high TdRPase activity in involved nodes was significantly associated with a poor prognosis. On the other hand, although adjuvant chemotherapy was found to improve the survival of patients, TdRPase activity in the tumor did not show any significant relationship with the efficacy of chemotherapy with 5-FU or its derivatives.

CONCLUSIONS

The present study suggested that in pancreatic IDC the activity of TdRPase in primary lesions is different from that in metastatic lesions, and that DNA is synthesized mainly through the salvage pathway in primary lesions and through a de novo pathway in metastatic lesions. This may be one of the reasons for the heterogeneity in chemosensitivity of human pancreatic IDC.

Quantitative assay of telomerase activity in head and neck squamous cell carcinoma and other tissues

OBJECTIVES

To confirm the applicability and use of a new technique to detect and quantify telomerase activity of specimens from head and neck malignant neoplasms and to explore whether the levels of telomerase activity can be a useful marker for cancer risk assessment in head and neck malignant neoplasms.

DESIGN

Ninety-six specimens from 39 patients with head and neck malignant neoplasms were obtained. The specimens included 39 from patients with primary tumors (25 with head and neck squamous cell carcinoma and 14 with others), 10 from patients with neck metastases, 10 from patients with dysplasias, and 37 from patients with normal tissue. HeLa cell lines were used as positive control samples.

MAIN OUTCOME MEASURE

The levels of telomerase activity were determined using a liquid scintillation counter.

RESULTS

The new method has a high rate of outcome reproducibility. The intrabatch and extrabatch variations were 15.6% and 16.4%, respectively. The linear relationship was good between the telomerase activity and the value within 700 radioactive cpm (rcpm) to approximately 7000 rcpm. The levels of telomerase activity determined by radioactive count were more than 1000 rcpm in 42 of the 49 malignant specimens and much more than that in the normal tissues, with the exception of 3 specimens. The levels of telomerase activity in normal tissues were less than 1000 rcpm in every sample and less than that in the malignant neoplasm samples, with the exception of 1 specimen (P < .000). Higher levels of telomerase activity in 2 of 10 tissues from patients who had dysplasias were detected (2 specimens from patients who had severe dysplasia). The differences in the levels of telomerase activity between the head and neck squamous cell carcinomas and the other tumors were not statistically significant (P > .05).

CONCLUSIONS

Detection of telomerase activity in head and neck malignant neoplasms can be a useful marker for the assessment of cancer. Telomerase reactivation may play an important role in tumorigenesis in head and neck squamous cell carcinoma. The quantification of telomerase activity may have clinical diagnostic value for head and neck malignant neoplasms.

[Expression of BDNF and FGF-2 following axotomy in rat facial motoneurons]

OBJECTIVE

To study the expression and distribution of brain derived neurotrophic factor (BDNF) and fibroblast growth factor-2 (FGF-2) in normal facial motoneurons (FMNs) and in FMNs following axotomy.

METHODS

The right facial nerves were transected 6 mm distal to the stylomastoid foraman in adult Wistar rats except the normal group. Serial 20 microns cryosections were cut through the whole brainstems. Expressions of BDNF and FGF-2 mRNA as well as BDNF and FGF-2 protein were studied by in situ hybridization, immunohistochemistry and image analysis.

RESULTS

BDNF mRNA and its protein were observed in widespread areas of normal rat facial nucleus, and those increased 1 day after axotomy. In addition to neurons, glial cells were also stained. FGF-2 mRNA and its protein were mainly localized in normal FMNs of ventral facial nucleus. After axotomy, expression of FGF-2 mRNA started to up-regulate in FMNs at 7 days, however FGF-2 protein drastically reduced at 3 and 7 days.

CONCLUSION

In addition to target-supporting, there may be BDNF autocrine and paracrine mechanisms as well as FGF-2 autocrine mechanisms in normal rat FMN. When target-derived BDNF is deprived, alternative sources of BDNF support may substitute immediately after axotomy. However, deprivating of target--derived FGF-2 may result in down-regulation of FGF-2 protein in adult rat FMNs at early stage after axotomy. These suggest that the exogenous FGF-2 might provide a supportive environment for the recovery of metabolism and function of FMNs at early stage following axotomy.

Apoptosis and expression of Bcl-2 and Bax proteins in invasive ductal carcinoma of the pancreas

The Bcl-2 family of genes plays important roles in the regulation of apoptosis. The present study was designed to assess the clinicopathologic significance of apoptosis and the expression of the apoptosis-inhibitory Bcl-2 protein (pBcl-2) and the apoptosis-promoting Bax protein (pBax) in human invasive ductal carcinomas (IDCs) of the pancreas. The present study included 66 IDCs that were resected between 1982 and 1998. Apoptosis was assessed by the in situ nick end labeling method and pBcl-2 and pBax were stained immunohistochemically. Apoptosis was quantified as the apoptotic index (AI, the percentage of apoptotic cells of the total tumor cells), and a high AI (>10%) was observed in 26 of the 66 (39%) IDCs. The AI correlated significantly with the extent of nodal involvement. pBax immunoreactivity was detected in 42 of 66 IDCs (64%), and pBax expression was significantly correlated with female gender and showed a significant negative correlation with the extent of nodal involvement. pBcl-2 was expressed in 16 IDCs (24%) but did not show any correlation with the clinicopathologic factors. The AI did not correlate with the expression of pBcl-2 or pBax, but there was a significant correlation between the expression of pBcl-2 and that of pBax; 15 of the 16 pBcl-2(+)IDCs were also pBax(+), and only one pBcl-2(+)IDC was pBax(-). Univariate analysis demonstrated that the degree of apoptosis had no significant influence on the patients' prognosis, pBax or pBcl-2 expression was significantly associated with a better prognosis, and in particular, the pBax(+)pBcl-2(+) group had a significantly higher survival than the other groups. On the other hand, the survival curve of the adjuvant chemotherapy (ACT) group was also higher than that of the surgery alone (SA) group, with borderline statistical signfiicance. The ACT group showed a significantly better survival rate than the SA group for the pBax(+)IDC patients, but the AI and pBcl-2 expression were not correlated with an improved survival rate in the ACT group. Multivariate analysis showed that the AI. pBcl-2 expression, and pBax expression by themselves did not represent significant variables for death owing to IDC, but pBax expression was significantly associated with the efficacy of ACT. In conclusion, pBax expression may be essential for pBcl-2 expression. pBcl-2 and pBax expressions are not significant prognostic factors for patients with IDC, but pBax expression may be beneficial in predicting the effects of ACT on patients with IDC.

Expression of Bcl-2 and p53 protein in resectable invasive ductal carcinoma of the pancreas: effects on clinical outcome and efficacy of adjuvant chemotherapy

BACKGROUND AND OBJECTIVES

p53 tumor suppressor gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair. The Bcl-2 can work to protect cells from apoptosis, which is induced by p53 gene. These facts suggest the significant role of these genes in the genesis and progression of various tumors. The present study was designed to assess the significance of p53 and Bcl-2 protein (pBcl-2) expression on resectable invasive ductal carcinoma (IDC) of the pancreas.

METHODS

The present study included 63 IDCs, which were resected between 1982 and 1998. pBcl-2 and p53 were stained immunohistochemically with monoclonal antibodies.

RESULTS

pBcl-2 was expressed in 16 (25.4%), and p53 was positively expressed in 32 out of 63 IDCs (50.8%); however, expression of pBcl-2 did not necessarily correlate with that of p53. Although p53 expression did not show any significant influence on the patients' survival, pBcl-2(+) patients showed a higher survival than pBcl-2(-) patients for both p53(+) and p53(-) patients, which suggested that pBcl-2 expression had a more significant effect on the survival of patients than p53 expression. On the other hand, there were no differences in the survival curve between the adjuvant chemotherapy (ACT) group and the surgery alone (SA) group. pBcl-2 expression had no influence on the effect of ACT, the ACT group showed a significantly better survival than the SA group for p53(+) IDC patients.

CONCLUSIONS

pBcl-2 expression is a beneficial prognostic factor for patients with IDC, whereas p53 expression may be beneficial in the prediction of the effects of adjuvant chemotherapy on patients with IDC. J. Surg. Oncol. 2001;76:188-196.

[Study on the relation between the cell cycle regulators and laryngeal carcinogenesis]

OBJECTIVE

To investigate the clinicopathological significance of the Cyclin E, p21WAF1/CIP1 and p53 expression in laryngeal carcinogenesis.

METHOD

The expression of Cyclin E, p21WAF1/CIP1 and p53 was examined by using immunohistochemical method in normal epithelia (20), dysplastic epithelia (40) and laryngeal cancers (60).

RESULT

1. In normal epithelium, dysplastic squamous epithelium and in squamous cell carcinoma of the larynx, the positive immunostaining rate of Cyclin E protein was 5.0%(1/20), 20.0%(8/40) and 45.0%(27/60) respectively (P < 0.001), and p21WAF1/CIP1 protein was 95.0%(19/20), 75.0%(30/40) and 63.3%(38/60) respectively (P < 0.01), while the rate of p53 was 0, 30.0%(12/40) and 61.7%(37/60)(P < 0.001) respectively. 2. p21WAF1/CIP1 positive expression in highly, moderately and poorly differentiated carcinomas were 76.2%(16/21), 66.5%(19/29) and 30.0%(3/10) respectively (P < 0.05), p21WAF1/CIP1 protein expression was significantly associated with tumour cell differentiation. 3. The positive expression of Cyclin E closely related with the positive expression of p53 (P < 0.05). No correlation was found between p21WAF1/CIP1 expression and p53 expression.

CONCLUSION

1. Cyclin E and p53 could be an early molecular event in the carcinogenesis of larynx. 2. p21WAF1/CIP1 expression is associated with tumour cell differentiation. 3. The mutual mechanism of cell cycle regulators (Cyclin E, p21WAF1/CIP1 and p53) play an important role in the laryngeal carcinoma.

Dual contacts between peptide agonist ligands and the secretin receptor directly established by photoaffinity labeling

Structural analysis of secretin in solution has demonstrated extended helical domains within both amino- and carboxyl-terminal halves, with a possible turn in between. However, the conformation of this peptide as it resides in its binding site within the receptor has not been established. In the work reported here, we performed affinity labeling of the secretin receptor with radioiodinated secretin analogues having photolabile benzoyl-phenylalanine residues positioned in each half of the peptide. The probes had sites of covalent attachment in positions 6 and 22, and have been recently synthesized and characterized to represent high affinity agonist ligands. Both covalently labeled the secretin receptor in a saturable, specific, and efficient manner. After purification of the labeled receptor, we used a series of chemical and enzymatic cleavage techniques to define the domain of labeling. We complemented this by receptor mutagenesis, followed by additional cleavage and Edman degradation sequencing to refine our insights into the labeled residues. This has allowed us to demonstrate that sites of attachment were both within the extracellular aminoterminal domain of the receptor. Of particular interest, both probes labeled residues within the amino-terminal thirty residues at the distal end of the receptor. It will be particularly interesting to use these molecular approximations to model the binding domain of this important receptor.

[Determination of protocatechualdehyde in yu xue bi granula]

The content of Protocatechualdehyde in YuXueBi granula was determined by HPLC. The chromatographic column was packed with ODS-2 (particle size 5 microns). The mobile phase was MeOH-H2O-H3PO4(17:83:0.003) adjusted to pH 3 with N(C2H5)3. The detection wavelength was 280 nm. The velocity of flow was 1.0 ml/min. The average recovery rate was 96.14%, RSD was 1.16%. The method was simple and stable.

[Isolation and identification of steroidal saponins from Dioscorea panthaica Prain et Burkill]

AIM

To investigate the chemical constituents of the rhizomes of Dioscorea panthaica Prain et Burkill and look for new active compounds.

METHODS

The compounds were isolated with silica gel and HPLC, and their structures were elucidated on the basis of chemical evidences and spectral analysis (IR, ESI-MS, 1HNMR, 13CNMR, DEPT, 1H-1H COSY, HMQC, HMBC, NOESY).

RESULTS

Three steroidal saponins were isolated from the rhizomes of Dioscorea panthaica. They were elucidated as 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-23(S)-methoxy-25(R)-delta 5,20(22)-diene-furosta-3-O-[alpha-L-rhamnopyranosyl-(1-->2)- O-alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (I), pseudoprotodioscin (II), 26-O-beta-D-glucopyranosyl-3 beta, 26-diol-25 (R)-delta 5,20(22)-diene-furosta-3-O-alpha-L-rhamnopyranosyl- (1-->2)-O-beta-D-glucopyranoside (III).

CONCLUSION

Compound I is a new steroidal saponin and was named as dioscoreside C. Compound II and III were obtained from this genus for the first time.

A new sesquiterpene lactone glucoside from Ixeris sonchifolia

A new sesquiterpene lactone glucoside, Ixerin Z1 (1), was isolated from the whole plants of Ixeris sonchifolia (Bge.) Hance, along with 15 known compounds. The structure of 1 was elucidated as 1(10),3,11(13)-guaiatriene-12,6-olide-2-one-3-O-[6'-(p-hydroxyphenylacetyl)]-glucopyranoside by spectroscopic methods including 2D-NMR techniques.

[Changes of maternal and umbilical serum nitric oxide in patients with the intrauterine growth retardation]

OBJECTIVE

To determine whether the levels of maternal and umbilical serum nitric oxide (NO) were changed in cases of intrauterine growth retardation (IUGR).

METHODS

Fifteen pregnant women with fetuses of IUGR (IUGR group) and 25 normal pregnant women in late trimester (normal control group) were studied. Maternal and fetal umbilical venous blood were collected from all the cases. Serum NO2-/NO3-, the end products of NO, were measured with the Griess reaction after reduction with nitrate reductase.

RESULTS

Mean NO2-/NO3- values in maternal serum were (74.22 +/- 28.99) mumol/L in IUGR group and (56.71 +/- 22.81) mumol/L in the control. Umbilical serum NO2-/NO3- values were (39.73 +/- 24.65) mumol/L in IUGR group and (21.49 +/- 6.69) mumol/L in the control. Compared with the control, maternal as well as umbilical serum NO2-/NO3- in IUGR group were significantly higher (P < 0.05 and P < 0.001, respectively). The total nitrite levels in fetal circulation were lower than in maternal circulation in both groups (P < 0.05).

CONCLUSIONS

Changes of NO in the pregnant women and their fetuses were due to the result of secondary complementary response in the patients with IUGR. The metabolic disorder of nitric oxide in maternal and fetal circulation may play an important role in pathogenesis of IUGR.

Structural insights into the amino-terminus of the secretin receptor: I. Status of cysteine and cystine residues

The secretin receptor is prototypic of the class II family of G protein-coupled receptors, with a long extracellular amino-terminal domain containing six highly conserved Cys residues and one Cys residue (Cys(11)) that is present only in the most closely related family members. This domain is critical for function, with some component Cys residues believed to be involved in key disulfide bonds, although these have never been directly demonstrated. Here, we examine the functional importance of each of these residues and determine their involvement in disulfide bonds. Secretin binding was markedly diminished after treating cells with cell-impermeant reducing reagents, supporting the presence of important extracellular disulfide bonds. To determine whether the amino-terminal domain was covalently attached to the receptor body by disulfide linkage, a strategy was implemented that involved introduction of an acid-labile Asp-Pro sequence to enable specific cleavage at the boundary of these domains. Under nonreducing conditions, the amino terminus was released from the receptor body, supporting the absence of covalent association between these domains. Quantitative [(14)C]iodoacetamide incorporation into the isolated amino-terminal domain of the receptor in the absence and presence of chemical reduction established the ratio of free to total Cys residues as 1:7, consistent with three disulfide bonds. Mutagenesis of each of the amino-terminal Cys residues to Ala was tolerated only for Cys(11), suggesting that these bonds linked the conserved Cys residues. This was further supported by treatment of intact cells expressing wild-type or C11A mutant secretin receptor with a cell-impermeant sulfhydryl-reactive reagent. Thus, the functionally important amino terminus of the secretin receptor represents a structurally independent, highly folded, and disulfide-bonded domain, with a pattern that is likely critical and conserved throughout this receptor family.

Comparison of K-ras point mutations at codon 12 and p21 expression in pancreatic cancer between Japanese and Chinese patients

BACKGROUND AND OBJECTIVES

K-ras (Kirsten-ras) point mutation (PM) in codon 12 are suggested to be significantly associated with the tumorigenesis of pancreatic cancer. The incidences of K-ras PMs in human pancreatic cancer are reported to be different between Europeans and Japanese. The present study was designed to compare the incidences and profile of K-ras PMs and ras-p21 expression in primary invasive ductal carcinoma (IDC) of the pancreas between Japanese and Chinese.

METHODS

The specimens included 51 Japanese and 34 Chinese patients with the primary IDC of the pancreas. K-ras PMs were tested by allele specific oligonucleotide dot blot hybridization methods and ras-p21 expression was stained by the immunohistochemical method.

RESULTS

K-ras PMs were detected in 48 Japanese IDCs (94%) and in 24 Chinese ones (71%). There was a significant difference between the two groups. The GAT mutation was more frequent both in Japanese (61%, 33/54) and in Chinese (60%, 18/30) IDCs. The transitions/transversions ratio in the Japanese group was 2.4 in this study. By contrast, that in the Chinese group was 1.5. The expression of p21 was detected in 24 Japanese IDCs (47%) and in 24 Chinese IDCs (71%). There was a significant difference between the two groups. The expression of p21 and the patterns of K-ras PMs did not show any significant influence on the survival of the patients both in Japanese and Chinese. In the present study, Chinese IDC had a lower frequency of K-ras PMs in codon 12 than Japanese IDC. The pattern of K-ras PMs in Chinese IDC was different from that in Japanese and European IDC, respectively.

CONCLUSIONS

Ki-ras PM and p21 expression were frequently seen both in Japanese and Chinese patients with pancreatic cancer. Factors such as lifestyle and environment may have influences on pancreatic carcinogenesis in various populations.

Effect of Solution Gas in Oil on CO2 Minimum Miscibility Pressure

Abstract

In this study, a rising bubble apparatus (RBA) was used to determine the CO2 MMP for various oils. RBA tests permit direct observation of changes in bubble behaviour and thus offered insight into the phase behaviour for the CO2-reservoir fluid system. The CO2 MMPs were estimated for two Steelman reservoir fluids with a high gas-oil ratio, the partially flashed reservoir fluids, and the dead oils. The composition of solution gas of each partially flashed reservoir fluid was determined and the effects of different gas components were analysed. The MMP was also determined and discussed for Weyburn reservoir fluids which had a low gas-oil ratio with pure and impure CO2. The results of this study demonstrated that the effect of solution gas in oil on CO2 MP could be significant. Furthermore, achieving a miscible CO2 flood (in a reservoir with a Steelman-like reservoir fluid) could be possible at a lower operating pressure than the measured CO2 MMP, by partially depleting the reservoir. This may be the only option for some reservoirs which cannot sustain the relatively high pressure required for achieving miscibility.

Introduction

Carbon dioxide flooding is a proven oil recovery process(1). Over the last decade, carbon dioxide injection has become the leading enhanced oil recovery (EOR) process for light oils(2). CO2 injection can prolong, by 15 to 20 years, the production life of light oil fields nearing depletion under waterflood, and may recover 15 to 25% of the original oil in place. More than 20 years of field experience of CO2 injection has advanced the CO2 technology. CO2 injection can be introduced gradually and use some of the same equipment currently in place for waterflooding.

Saskatchewan's light and medium oil resource, representing nearly 45% of proven reserves, has been on waterflood for over 30 years and is fast approaching its economic limit of production(3). For the light and medium oil reservoirs in Saskatchewan, carbon dioxide or hydrocarbon injection is considered to be the most effective EOR process(4–6). These gases can be injected into the reservoir to develop miscible or immiscible conditions with the oil depending upon the operating pressure. Carbon dioxide is preferred over hydrocarbon gases (e.g., ethane, propane) because it is cheaper, has higher density, and offers environmental benefits by providing storage for CO2 in the reservoir. The Saskatchewan Research Council (SRC) is conducting a comprehensive research program to assess the suitability of miscible CO2 displacement for reservoirs in southeast Saskatchewan and to optimize the field operating procedures.

The first step in determining if a field is a viable CO2 flood candidate is to conduct a screening study to provide a reasonable estimate of CO2 injection performance. The minimum miscibility pressure (MMP) is a key parameter used in the assessment. It has been recognized that the CO2 MMP for a reservoir oil depends on the reservoir temperature, oil composition, and the purity of injected CO2. The minimum miscibility pressure increases with increasing reservoir temperature.

Effects of pioglitazone on promoting energy storage, not expenditure, in brown adipose tissue of obese fa/fa Zucker rats: comparison to CL 316,243

Recent advances in the treatment of non-insulin-dependent diabetes mellitus (NIDDM) include the use of thiazolidinediones (TZDs), agents that enhance insulin action, in part, through an activation of adipose tissue peroxisome proliferator-activated receptor gamma. Current evidence also indicates that these agents upregulate uncoupling protein 1 (UCP1) gene expression in brown adipocytes and increase interscapular brown adipose tissue (IBAT) mass in rodents, suggestive of a thermogenic component to their mechanism of action. In the present study, the TZD pioglitazone (PIO) and the beta3-adrenoceptor agonist CL 316,243 (CL), were used to determine whether the antidiabetic effects of PIO, like those of CL, may, in part, be mediated by an increase in either IBAT thermogenesis or whole-body energy expenditure. Treatment of obese, insulin resistant fa/fa Zucker rats with PIO for 10 days resulted in a 2- to 3-fold increase in IBAT mass, due largely to an increase in adipocyte size and number, and increased fatty acid biosynthesis. However, unlike the effects of CL, the PIO-induced IBAT changes were not associated with an increase in UCP1 expression or whole-body energy expenditure. In contrast to CL, PIO substantially increased body weight gains over the 10-day treatment period by increasing feeding efficiency. These data suggest that, unlike CL, the actions of PIO in the obese Zucker rat does not include increased energy expenditure, but rather strengthens its role as an adipogenic and lipogenic agent, which promotes energy storage.

Expression of transforming growth factor beta1 and its type II receptor in mouse colon tumors induced by azoxymethane

Alterations in transforming growth factor beta1 (TGF-beta1) and its type II receptor (TbetaR-II) have been implicated in the pathogenesis of a variety of human cancers and animal tumor models. We postulated that TGF-beta1 and TbetaR-II alterations may also be involved in mouse colon tumorigenesis induced by the chemical carcinogen, azoxymethane (AOM). In the present study, normal colon tissues and AOM-induced colon tumors from SWR/J mice were analyzed for mutational changes in the TbetaR-II gene, and the expression and localization of TGF-beta1 and TbetaR-II were examined by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemisty. Direct DNA sequencing of the coding sequence of the TbetaR-II gene revealed no mutational changes in tumors induced by AOM when compared with the sequence from normal colon tissue. However, TGF-beta1 and TbetaR-II mRNA levels in tumor samples were increased 1.8-fold (p<0.01) and 1.3-fold (p<0.01), respectively, when compared with control mouse colon tissue. The results of immunohistochemical analysis of TGF-beta1 and TbetaR-II were correlated with mRNA expression data. An increase in staining intensity of both TGF-beta and TbetaR-II were observed in colon tumors. These findings suggest that alterations in the expression of TGF-beta1 and TbetaR-II may be involved in the pathogenesis of colon tumors induced by AOM in mice.

Reduced invasiveness and metastasis of Chinese hamster ovary cells transfected with human interleukin-17 gene

Human IL-17 (hIL-17) stimulates epithelial, endothelial, fibroblastic cells and macrophages to secrete various cytokines. The present study was designed to assess the effects of the transfection of the hIL-17 gene in Chinese hamster ovary (CHO) cells. A complementary DNA (cDNA)-encoding hIL-17 was obtained by polymerase chain reaction (PCR) amplification from human CD4+ T-cell cDNA and inserted into the plasmid pRc/CMV to construct an expression vector for hIL-17. CHO cells were transduced with hIL-17 DNA-carrying cytomegalovirus (CMV)-based retroviral vectors. A clone with a high mRNA expression of hIL-17 (CHO/IL-17) was selected by Northem blotting. There was no significant difference in the in vitro growth of cells among parent CHO cells, vector-only transfected cells (CHO/neo) and CHO/IL-17 cells. A Matrigel invasion chamber assay, however, demonstrated significantly lower invasiveness by CHO/IL-17 cells than by either the parent CHO or the CHO/neo cells. There was no difference in the in vivo growth among the cells, when subcutaneously transplanted into nude mice. When injected into the tail vein, however, the number of metastatic nodules in the lungs of CHO/IL-17-injected mice was significantly smaller than that of CHO- or CHO/neo-injected mice. Furthermore, NK activity of spleen cells was significantly higher in nude mice transplanted with CHO/IL-17 cells than in mice transplanted with parent CHO or CHO/neo cells. In conclusion, the hIL-17-gene-transfected CHO cells showed a significantly lower metastatic potential to the lung by directly modulating the invasiveness and metastasis of CHO cells as well as by enhancing NK activity.

Identification of two pairs of spatially approximated residues within the carboxyl terminus of secretin and its receptor

The carboxyl-terminal domains of secretin family peptides have been shown to contain key determinants for high affinity binding to their receptors. In this work, we have examined the interaction between carboxyl-terminal residues within secretin and the prototypic secretin receptor. We previously utilized photoaffinity labeling to demonstrate spatial approximation between secretin residue 22 and the receptor domain that includes the first 30 residues of the amino terminus (Dong, M., Wang, Y., Pinon, D. I., Hadac, E. M., and Miller, L. J. (1999) J. Biol. Chem. 274, 903-909). Here, we further refined the site of labeling with the p-benzoyl-phenylalanine (Bpa(22)) probe to receptor residue Leu(17) using progressive cleavage of wild type and mutant secretin receptors (V13M and V16M) and sequence analysis. We also developed a new probe incorporating a photolabile Bpa at position 26 of secretin, closer to its carboxyl terminus. This analogue was also a potent agonist (EC(50) = 72 +/- 6 pm) and bound to the secretin receptor specifically and with high affinity (K(i) = 10.3 +/- 2.4 nm). It covalently labeled the secretin receptor at a single site saturably and specifically. This was localized to the segment between residues Gly(34) and Ala(41) using chemical and enzymatic cleavage of labeled wild type and A41M mutant receptor constructs and immunoprecipitation of epitope-tagged receptor fragments. Radiochemical sequencing identified the site of covalent attachment as residue Leu(36). These new insights, along with our recent report of contact between residue 6 within the amino-terminal half of secretin and this same amino-terminal region of this receptor (Dong, M., Wang, Y., Hadac, E. M., Pinon, D. I., Holicky, E. L., and Miller, L. J. (1999) J. Biol. Chem. 274, 19161-19167), support a key role for this region, making the molecular details of this interaction of major interest.

[Image and quantity analysis of blood-gas in rabbit's artery and Na(+)-K(+)-ATPase in their lungs during PE-SWD treated by HFJV]

This study was made to gain an insight into the mechanism of high-frequency jet ventilation(HFJV) treatment for the pulmonary edema after seawater drowning(PE-SWD). PaO2, PaCO2 and oxygen saturation (SaO2) of the rabbit and Na(+)-K(+)-ATPase in the rabbit's lungs in three groups--PE-SWD group(PE-SWD-G), HFJV group (HFJV-G) and control group(CG), were measured and analysed by the blood-gas analyser and computer image system. The results showed that, after 100 minutes' HFJV, the PaO2, SaO2 and the activity of Na(+)-K(+)-ATPase in the lung capillary endothelial cells in HFJV-G were significantly higher than those in PE-SWD-G(P < 0.01 or P < 0.05). Three parameters of Na(+)-K(+)-TAPase(G1, D1 and D2) in HFJV-G almost returned to their values in CG. The authors suggest that the increase of PaO2 and SaO2 in the rabbit's artery blood in HFJV-G is closely related to the rehabilitation of Na(+)-K(+)-ATPase activity in the lungs after HFJV. The mechanism of successful HFJV treatment for PE-SWD is that HFJV can better correct hypoxemia and improve the rehabilitation of Na(+)-K(+)-ATPase activity in the rabbit's lungs.

[Measurements of interleukin-6, interleukin-8 and transforming growth factor-beta 1 levels in peritoneal fluid of patients with endometriosis]

OBJECTIVE

To investigate the role of cytokines in peritoneal fluid on pathogenesis of endometriosis (EM).

METHODS

Interleukin-6 (IL-6), interleukin-8(IL-8) and transforming growth factor-beta 1 (TGF-beta 1) contents in peritoneal fluid (PF) of 31 cases with EM were detected by enzyme linked immunoabsorbent assay (ELISA) and compared with the counterparts of 22 cases without EM (controls). The correlation analyses between cytokine concentrations in peritoneal fluid of EM patients and the severity of EM or dysmenorrhea score were performed.

RESULTS

The peritoneal fluid from patients with EM contained significantly greater amounts of IL-6 [(1.8 +/- 0.4) ng/L] and IL-8 [(1.7 +/- 0.5) ng/L] than those in controls [(1.2 +/- 0.2) ng/L and (1.4 +/- 0.3) ng/L respectively, P < 0.05]. However, in the amounts of TGF-beta 1 there were no significant difference (P > 0.05) between the two groups. The highest PF IL-6 and IL-8 concentrations were found in stage II, III and stag I, II EM respectively. A significant correlation between PF IL-6 content and the severity of disease was noted but there were no evidences of a relationship between concentrations of IL-8 and TGF-beta 1 and the severity of EM as well as between concentrations of three cytokines and dysmenorrhea score.

CONCLUSION

Unusual levels of IL-6 and IL-8 in PF of EM patients partly account for imbalance of the immunologically dynamic environment in peritoneal cavity of EM patients.

Indirect neurotrophic effect of neuropeptide ZNC(C)PR on PC12 cells via peptide-stimulation of C6 cells

AIM

To understand the mechanism of neurotrophic action of neuropeptide ZNC(C)PR and its effect on which could affect both growth and apoptosis of C6 cells.

METHODS

Effects of ZNC(C)PR-treated C6 conditioned medium was observed on on culture of PC12 cells. The development of PC12 cells was determined by ratio of neurite-bearing cells in the total cells. The specific binding of ZNC(C)PR on C6 cells was determined by radioligand binding assay (RBA).

RESULTS

ZNC(C)PR-treated C6 conditioned medium increased the ratio of neurite-bearing PC12 cells by 36% compared to the untreated C6 conditioned medium or to a mixture of ZNC(C)PR with the untreated C6 conditioned medium. RBA showed a specific binding site of ZNC(C)PR on C6 cells with Kd value of 2.74 nmol.L-1 and Bmax value of 19 pmol.g-1 protein.

CONCLUSION

ZNC(C)PR enhanced C6 cells induced secretion of some neurotrophic factors which acted as enhancers for PC12 cells differentiation, through its specific receptor sites on the neuroglioma cell.

(10E,12Z,15Z)-9-hydroxy-10,12,15-octadecatrienoic acid methyl ester as an anti-inflammatory compound from Ehretia dicksonii

The methanol extract of Ehretia dicksonii provided (10E, 12Z, 15Z)-9-hydroxy-10,12,15-octadecatrienoic acid methyl ester (1) which was isolated as an anti-inflammatory compound. Compound 1 suppressed 12-Otetradecanoyl-phorbol-13-acetate (TPA)-induced inflammation on mouse ears at a dose of 500 microg (the inhibitory effect (IE) was 43%). Linolenic acid methyl ester did not inhibit this inflammation at the same dose. However, the related compounds of 1, (9Z,11E)-13hydroxy-9,11-octadecadienoic acid (5) and (9Z,llE)13-oxo-9,11-octadecadienoic acid (6), showed potent activity (IE500 microg of 63% and 79%, respectively). Compounds 1, 4 ((9Z, 12Z, 14E)-16-hydroxy-9,12,14-octadecatrienoic acid), 5 and 6 also showed inhibitory activity toward soybean lipoxygenase at a concentration of 10 microg/ml.

Ki-ras point mutation and p53 expression in human pancreatic cancer: a comparative study among Chinese, Japanese, and Western patients

The aim of this study was to clarify features of Ki-ras point mutation (PM) and p53 expression in Chinese pancreatic cancer and to compare those with that in other countries. Dot blot hybridization and immunohistochemical methods were performed in 59 Chinese patients. The results showed that Ki-ras PMs at codon 12 and p53 expression were frequent in this group. No relationships were found between Ki-ras PM alone and p53 expression alone, and clinicopathological parameters, including age, gender, clinical stage, and histological grade and classification in Chinese patients. However, their cooperation was significantly associated with a poor prognosis in this group. Comparison showed that there were significant differences in the overall frequency and substitution of Ki-ras PM and in the ratio of transition:transversion in pancreatic cancer among various countries. In addition, the effect of Ki-ras PM and p53 expression on a poor prognosis of pancreatic cancer may be different among various countries. These findings suggested that not only Ki-ras PM and p53 expression are frequent in Chinese pancreatic cancer, but also a gene component to pancreatic cancer may be different between Asian and Western pancreatic cancer. In addition, it seems that cooperation of Ki-ras PM and p53 expression may predict a poor prognosis in Chinese patients with pancreatic cancer.

[The effects of PDGF-AB on pro alpha 1 (III). mRNA expression of fibroblasts]

OBJECTIVE

To investigate the mechanism of PDGF-AB to promote wound healing and its role during the process of scar formation.

METHODS

In vitro cultured fibroblasts of human normal skin and hypertrophic scar were treated with PDGF-AB. The expression of Pro alpha 1 (III) mRNA of the fibroblasts was evaluated by in situ hybridization technique.

RESULTS

PDGF-AB could increase Pro alpha 1 (III) mRNA expression of fibroblasts of both normal skin and hypertrophic scar in a dose-dependent manner. However, the effect of PDGF-AB on hypertrophic scar fibroblasts was stronger.

CONCLUSIONS

PDGF-AB may promote wound healing by stimulating extracellular matrix synthesis, e.g. collagen. PDGF-AB may also play a role in scar formation through collagen deposition.

Laboratory Investigation of Weyburn CO2 Miscible Flooding

Abstract

Weyburn reservoir, located in southeast Saskatchewan and operated by PanCanadian Petroleum Ltd., has reached its economic limit of production by waterflooding. The reservoir is a target for tertiary CO2 miscible flooding to enhance oil recovery and extend its production life. A comprehensive study has been conducted by the Saskatchewan Research Council and PanCanadian to assess the suitability of the process for Weyburn.

This paper presents a technical evaluation of CO2 near-miscible injection for Weyburn reservoir. This is based on laboratory studies conducted with three Weyburn oils collected from different regions of the reservoir. These studies included:measurement of minimum miscibility pressure for the reconstituted reservoir fluids for pure and impure CO2,determination of PVT properties for reservoir fluid-CO2 mixtures, andassessment of recovery behavior from uniquely designed laboratory core-flood tests representing the permeability contrast of the reservoir.

The studies indicated that the CO2 minimum miscibility pressure for the Weyburn reservoir oils varied from about 11.5 to 14.5 MPa, indicating suitability for CO2 miscible flooding. PVT data generated for the three Weyburn reservoir fluid-CO2 mixtures showed that viscosity reduction and oil swelling by CO2 also contributed to oil recovery. A slight manipulation of the measured PVT properties of the mixtures made it possible to obtain single property curves for the three Weyburn oils. This feature can be used to estimate the PVT behavior for any Weyburn oil from the reservoir. Core-flood studies showed that CO2 injected into the Vuggy zone could rise to the upper Marly zone and help enhance oil recovery. A separate simulation and modelling study conducted by PanCanadian Petroleum Ltd. satisfactorily matched the experimental PVT properties, MMP values and recovery mechanism suggested by the core-flood behaviour.

Introduction

The total oil reserves of Saskatchewan are estimated at over 3 billion m3 of initial oil-in-place (IOIP). The light and medium oil reserves contribute approximately 1.6 billion m3 IOIP(1). Over 10﹪ of the light and medium reserves, or 178 million m3 IOIP, are held in Weyburn reservoir. The Weyburn field is located approximately 130 km southeast of Regina in Saskatchewan and covers over 180 km2 of production area. The field was discovered in 1955 and PanCanadian Petroleum (PCP) Ltd. is the major operator. It has over 627 producing wells and 162 water injection wells on approximately 24 ha spacing(2).

The oil production from the Weyburn field comes from Midale beds of the Mississippian Charles Formation in the Williston Basin at a depth of 1,310 to 1,500 m. The field was produced by primary depletion for about nine years until 1964. Waterflood was started thereafter using a nine-spot pattern. In 1985, to optimize the waterflood performance, both horizontal and vertical infill drilling programs were initiated. The combined oil recovery by primary and secondary production was approximately 28﹪ IOIP by 1994. Waterflooding has almost reached its economic limit for the Weyburn reservoir. The ultimate conventional recovery is expected to be 31﹪ IOIP, leaving a large target for tertiary recovery techniques(3). A similar situation exists for the majority of Saskatchewan's light and medium reservoirs(1,4).

[Analysis for the titer of plasma antibody to heat stress protein 70 in workers exposed to benzene]

OBJECTIVE

To explore the titer of plasma antibody against heat stress protein 70 (HSP70) in workers exposed to benzene and its possible relationship to their health.

METHODS

Forty-two workers exposed to more than 40 mg/m(3) of benzene were selected as a high exposure group, 50 of workers exposed to less than 40 mg/m(3) as a low exposure group, and 42 unexposed as a control group. Their plasma antibody against HSP70 was determined with enzyme-linked immunosorbent assay (ELISA). Analysis was conducted to study the relationship between it and other factors.

RESULTS

Proportion of plasma positive antibody to HSP70 with a titer of 1:20 was significantly higher in high exposure group (26.2%) than that in controls (9.5%). Moreover, prevalence of adverse symptoms and positive signs, and level of lipid peroxide were all significantly higher in high exposure group with positive antibody to HSP70 than those with negative antibody.

CONCLUSION

It was concluded that the titer of plasma antibody to HSP70 had close relation with the health of workers exposed to benzene.

[The clinic features of human immunodeficiency virus (HIV) on ear, nose, throat head and neck]

OBJECTIVE

To identify the clinic features of HIV infection on ENT-Head and neck area and to explore its treatment.

METHOD

68 HIV cases in zambia were analysed.

RESULT

The ages of the patients are from 3 months to 46 year old. Among them 12 cases with Lump of neck, 9 with ulcer of oral-pharynx, 9 with parctid gland enlarged, 2 with submaxillary plleymon, 5 with nasal bleeding, 17 with purulent otitis Media, 4 with atrophic rhinitis. 18 cases in 58 HIV patients had tubericulosis, diarhea and anemia. 51 cases improved after treatment while 15 cases didn't improve and 2 died.

CONCLUSION

It is very important to find and treat HIV patients and to prevent transmission as early as possible.

[Immunohistochemical study of safe resection margin in the surgical treatment of laryngeal carcinoma]

OBJECTIVE

To study safe resection margin of laryngectomy according to the level of protein of gene expression.

METHOD

Using citric-LSAB-immunochemical technique, the expressions of ras, c-myc and P53 were studied in different regions of larynx including 30 cases laryngeal carcinoma, border area, adjacent mucosa which was 0.5, 1.0, 1.5, 2.0 cm away from cancer and four normal laryngeal mucosa.

RESULT

The results showed that both single expression and co-expression of p21, p62 and p53 increased as tissue progressed in sequence from normal mucosa, 2.0, 1.5, 1.0, 0.5 cm distant mucosa adjacent to carcinoma, border area and carcinoma. A significant different expression in most of them can be seen at regions of 0.5 cm and 1.0 cm distant from the tumor (P < 0.05).

CONCLUSION

The tissue 0.5 cm adjacent to the tumor should be regarded as precancerous lesion. It is appropriate to regard 0.5 cm away from tumors as resection margins for surgical treatment of laryngeal carcinoma.

3-Geranyl-4-hydroxy-5-(3'-methyl-2'-butenyl)benzoic acid as an anti-inflammatory compound from Myrsine seguinii

Bioassay-guided isolation of anti-inflammatory compounds from the methanol extract of Myrsine seguinii yielded an anti-inflammatory compound (1). The structure of compound 1 was elucidated to be 3-geranyl-4-hydroxy-5-(3'-methyl-2'-butenyl)benzoic acid on the basis of its spectroscopic data. Compound 1 strongly suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation on mouse ears at a dose of 500 micrograms (inhibitory effect (IE): 65%). The acetate and the methyl ether of 1 showed moderate activity at a 500-microgram application, with IE 38% and 27%, respectively. However, the methyl ester and the dimethyl derivative of 1 did not show activity at the same dose. The related compounds of 1, o-, m- and p-hydroxybenzoic acids also did not exhibit notable activity. These results indicate that the carboxylic acid and lipophilic terpene moieties of 1 were significant structural features for anti-inflammatory activity.

Effects of the configuration of a multi-epitope chimeric malaria DNA vaccine on its antigenicity to mice

OBJECTIVE

Four B and Th cell epitopes were selected from conservative domain of Plasmodium falciparum antigens to construct two groups of chimeric malaria DNA vaccines with different configurations and their antigenicities were studied.

METHODS

The partially synthesized oligonucleotide was annealed, PCR amplified and cloned into a mammalian cell expression vector. By using a pair of isocaudamers on the vector, different single copies of B epitopes were multiplied and were tenderly stringed into two groups of chimeric DNA vaccine with different configurations. BALB/c mice were immunized with these DNA plasmids by either intramuscular or intradermal injections.

RESULTS

The antisera from the immunized mice tested by ELISA showed that only the configuration which had a single copy of universal T helper cell epitope, CS. T3, located at the C terminal of the multi-copy B cell epitopes induced a high antibody response. The T helper cell epitope at any other position of the peptide, or the double T helper cell epitopes configured with the B cell epitopes did not enhance antibody response, and some configurations even decreased the humoral response to a B cell epitope.

CONCLUSION

This study demonstrated that both combination and configuration of the epitope may affect the antigenicity of a chimeric multiple antigen.

Identification of an interaction between residue 6 of the natural peptide ligand and a distinct residue within the amino-terminal tail of the secretin receptor

Photoaffinity labeling is a powerful tool for the characterization of the molecular basis of ligand binding. We recently used this technique to demonstrate the proximity between a residue within the carboxyl-terminal half of a secretin-like ligand and the amino-terminal domain of the secretin receptor (Dong, M., Wang, Y., Pinon, D. I., Hadac, E. M., and Miller, L. J. (1999) J. Biol. Chem. 274, 903-909). In this work, we have developed another novel radioiodinatable secretin analogue ([Bpa6,Tyr10]rat secretin-27) that incorporates a photolabile p-benzoyl-L-phenylalanine (Bpa) residue into position 6 of the amino-terminal half of the ligand and used this to identify a specific receptor residue proximate to it. This probe specifically bound to the secretin receptor with high affinity (IC50 = 13.2 +/- 2.5 nM) and was a potent stimulant of cAMP accumulation in secretin receptor-bearing Chinese hamster ovary-SecR cells (EC50 = 720 +/- 230 pM). It covalently labeled the secretin receptor in a saturable and specific manner. Cyanogen bromide cleavage of this molecule yielded a single labeled fragment that migrated on an SDS-polyacrylamide gel at Mr = 19,000 that shifted to 10 after deglycosylation, most consistent with either of two glycosylated fragments within the amino-terminal tail. By immunoprecipitation with antibody directed to epitope tags incorporated into each of the two candidate fragments, the most distal fragment at the amino terminus was identified as the domain of labeling. The labeled domain was further refined to the first 16 residues by endoproteinase Lys-C cleavage and by cyanogen bromide cleavage of another receptor construct in which Val16 was mutated to Met. Radiochemical sequencing of photoaffinity-labeled secretin receptor fragments established that Val4 was the specific site of covalent attachment. This provides the first residue-residue contact between a secretin ligand and its receptor and will contribute substantially to the molecular understanding of this interaction.

The relationship between affect expression and affect recognition in schizophrenia

To examine the relationship between affect expression and affect recognition, we assessed 30 clinically stable, medicated schizophrenic inpatients. Affect expression was assessed using both a standard clinical rating scale (SANS) and a computerized acoustic voice analysis (VOXCOM). Affect recognition was assessed using the Florida Affect Battery (FAB). The schizophrenics' performance on the FAB was impaired, indicating broad deficits in affect recognition (p<0.05). There were no significant correlations between measures of affect expression and affect recognition, suggesting that the expressive impairment in schizophrenia is not related to their ability to discern emotions in others. SANS Inappropriate Affect, however, was negatively correlated with facial affect recognition (p = 0.001), suggesting that raters' impression of inappropriate affect may indicate a failure in the process of affect attunement.

[79 cases: a clinical analysis of hoarseness in children]

OBJECTIVE

To research the clinical characters of the hoarseness in children.

METHOD

79 cases are analysed retrospectively.

RESULT AND CONCLUSION

Age for this disease is usually 3 years old. People with irritable character are more easy to get it. Vocal nodule is the main cause to chronic hoarseness in children. Conservative treatment is important.

[Wavelet application to reduction of stimulus artifact in transient evoked otoacoustic emissions testing]

Otoacoustic emissions(OAEs) are presently considered as an objective clinical test for assessing the integraity of peripheral hearing. Owing to the adding of the reflex waves of the stimuli, recordings of emissions evoked in response to transient stimuli are contaminated by an initial artifact, which inhibits the examination of high frequency cochlear responses that have short latencies. So OAEs testing is of serious limitation in most clinical environments. We propose an artifact reduction technique based on discrete wavelet transform pre-processing method and demonstrate empirically that the method not only improves artifact reduction but also enhances signal-to-noise ratio in the response region.

Expression and characterization of HIV type 1 envelope protein associated with a broadly reactive neutralizing antibody response

We have studied envelope protein from a donor with nonprogressive HIV-1 infection whose serum contains broadly cross-reactive, primary virus NA. DNA was extracted from lymphocytes, which had been collected approximately 6 and 12 months prior to the time of collection of the cross-reactive serum, and env genes were synthesized, cloned, expressed on pseudoviruses, and phenotyped in NA assays. Two clones from each time point had identical V3 region nucleotide sequences, utilized CCR5 but not CXCR4 for cell entry, and had similar reactivities with reference sera. Analysis of the full nucleotide sequence of one clone (R2) demonstrated it to be subtype B and have normal predicted glycosylation. R2 pseudovirus was compared with others expressing env genes of various clades for neutralization by sera from U.S. donors (presumed or known subtype B infections), and from individuals infected with subtypes A, C, D, E, and F viruses. Neutralization by the U.S. sera of R2 and other clade B pseudoviruses was low to moderate, although R2 was uniquely neutralized by all. R2 was neutralized by 3/3, 3/3, 2/5, 5/8, and 3/4 clade A, C, D, E, and F sera, respectively. R2 and a clade E pseudovirus were neutralized by largely complementary groups of sera, potentially defining two antigenic subgroups of HIV-1. The results suggest that the epitope(s) that induced the cross-clade reactive NA in donor 2 may be expressed on the R2 envelope.

[The effect of insulin-like growth factor I and insulin on intrauterine fetal growth retardation]

OBJECTIVE

To evaluate the role of insulin-like growth factor I (IGF-I) and insulin (Ins) in the occurrence of intrauterine fetal growth retardation (IUGR).

METHODS

The study group included 17 women with IUGR, and 38 normal third trimester pregnant women were served as control. Maternal venous blood samples were collected from all cases before cesarean section. Umbilical venous blood and amniotic fluid were collected at the time of operation. The concentrations of Ins were measured by radioimmunoassay and concentrations of IGF-I were assayed by ELISA.

RESULTS

The maternal serum IGF-I in IUGR group (117.29 micrograms/L) was significantly lower than that in the control group (207.07 micrograms/L) (P < 0.002). The umbilical serum IGF-I in IUGR group (16.73 micrograms/L) was significantly lower than that in the control (44.89 micrograms/L) (P < 0.001). There was no significant difference of maternal serum Ins between IUGR group (12.18 mIU/L) and control group (7.13 mIU/L).

CONCLUSIONS

The change of IGF-I and Ins levels in maternal and umbilical serum may play an important role in the pathophysiological changes in IUGR.

[Post-operative respiratory failure in lung cancer patients.]

BACKGROUND

To explore the reasons , prevention and treatment measures of post-operative respiratory failure in lung cancer patients.

METHODS

Mechanical ventilation was given to 26 lung cancer patients with post-operative respiratory failure in our hospital fromJanuary 1990 to October 1997 , and 19 out of them received tracheotomy.

RESULTS

The incidence of post-operative respiratory failure was 4. 7 %(26/558) . Twenty cases were cured and 6 died (23. 1 %) .

CONCLUSIONS

Respiratory tract infection , operative wound , incision pain , abnormal pre-operative cardio-pulmonary function , etc , are the major reasons which caused post-operative respiratory failure. Correct diagnosis , tracheotomy as early as possible and mechanical ventilation are the most efficient ways to save lifes. Strengthening management on respiratory tract in peri-operative period and avoiding post-operative complications are the keys of preventing post-operative respiratory failure.

[Study on the relationship between epidermal growth factor and fetal growth retardation]

OBJECTIVE

To evaluate the significance of epidermal growth factor (EGF) in the development of fetal growth retardation (IUGR).

METHODS

EGF concentrations in amniotic fluid, maternal and fetal blood from 86 pregnant women in the third-trimester were determined by radioimmunoassay (RIA). These subjects were divided into control, large-for gestational age (LGA) group and IUGR group according to neonatal birth weights. EGF concentrations in blood samples taken from umbilical vein and artery of 11 controls were also analyzed.

RESULTS

No significant differences of EGF concentrations existed in amniotic fluid, maternal and fetal blood between control and LGA group (P > 0.2 for all). Compared to the control, EGF concentration of IUGR group in amniotic fluid decreased but those in maternal and fetal blood increased significantly (P < 0.05 for all). EGF concentration of cord serum in IUGR group was significantly higher than that in LGA group (P < 0.05), but no differences of EGF levels in amniotic fluid and maternal blood existed between the two groups (P > 0.05, for all). EGF in blood samples taken from umbilical vein and artery were at the same level (P > 0.1).

CONCLUSIONS

EGF in amniotic fluid, maternal and fetal blood may originate from different sources, and EGF may play a role in the development of IUGR.

Comparative significance of p53 and WAF/1-p21 expression on the efficacy of adjuvant chemotherapy for resectable invasive ductal carcinoma of the pancreas

p53 tumor-suppressor gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair. The cyclin-dependent kinase inhibitor WAF/1-p21 is induced by wild-type p53 and has been implicated as a downstream mediator of the growth-suppressing and apoptosis-promoting function of wild-type p53, suggesting an impact on the effectiveness of chemotherapy. This study was designed to assess the significance of p53 and WAF/1-p21 expression in the prognosis of patients and the efficacy of adjuvant chemotherapy for resectable invasive ductal carcinoma (IDC) of the pancreas. A total of 58 patients with primary IDC of the pancreas underwent pancreatectomy between 1982 and 1996: 28 patients underwent surgery alone, and 30 patients received postsurgical adjuvant chemotherapy. p53 and WAF/1-p21 were stained immunohistochemically with anti-p53 monoclonal antibody (mAb) and anti-WAF/1-p21 mAb. p53 was positively expressed in 29 (50%) of 58 primary lesions, and p21 was expressed in 24 (41%) lesions; however, p21 expression did not necessarily correlate with p53 expression. The survival curve of the patients with p53(+) IDC was significantly lower than that of those with p53(-) IDC, and p21(+) patients showed a higher survival curve than did p21(-) patients, but this difference was not statistically significant. When p53 and p21 expression were analyzed in combination, the patients with p53(+)p21(-) IDC were found to have a significantly poorer prognosis than others. On the other hand, the survival curve of the adjuvant chemotherapy group was also higher than that of the surgery-alone group, but this difference was not significant. In a multivariate analysis, p21 expression was a significantly low risk factor for death due to IDC overall, and adjuvant chemotherapy was found to decrease the risk of death from IDC in p53(+) patients. Evaluation of expression of p53 and WAF/1-p21 may be beneficial in the prediction of the patient's prognosis as well as prediction of the effects of adjuvant chemotherapy in pancreatic cancer patients.

Structurally related peptide agonist, partial agonist, and antagonist occupy a similar binding pocket within the cholecystokinin receptor. Rapid analysis using fluorescent photoaffinity labeling probes and capillary electrophoresis

The molecular basis of ligand binding to receptors provides important insights for drug development. Here, we explore domains of the cholecystokinin (CCK) receptor that are critical for ligand binding, using a novel series of fluorescent photolabile probes, receptor proteolysis, and rapid high resolution separation of peptide fragments by capillary electrophoresis. Each probe incorporated the same fluorophore and a photolabile p-benzoylphenylalanine at the amino terminus of the pharmacophoric domain (residue 24 of CCK-33) of CCK analogues representing full agonist, partial agonist, and antagonist of this receptor. Each was used to label the CCK receptor expressed on Chinese hamster ovary-CCKR cells, with the labeled domain then released by cyanogen bromide cleavage. Capillary electrophoresis with laser-induced fluorescence detection achieved an on-capillary mass sensitivity of 1.6 attomoles (10(-18) mol), with an excellent signal-to-noise ratio. Each of the biologically divergent, but structurally similar probes saturably and specifically labeled the same receptor domain, consistent with conservation of "docking" determinants. This had an apparent mass of 2.9 kDa, most consistent with the first extracellular loop domain. An additional probe having its site of covalent attachment in a different region of the probe (residue 29 of CCK-33) labeled a distinct receptor fragment with differential migration on capillary electrophoresis (third extracellular loop). Identification of the specific receptor residue(s) covalently linked to the amino-terminal probes must await further fragmentation and sequence analysis.

Demonstration of a direct interaction between residue 22 in the carboxyl-terminal half of secretin and the amino-terminal tail of the secretin receptor using photoaffinity labeling

An understanding of the molecular basis of hormonal activation of receptors provides important insights for drug design. Toward this end, intrinsic photoaffinity labeling is a powerful tool to directly identify the ligand-binding domain. We have developed a new radioiodinatable agonist ligand of the secretin receptor that incorporates a photolabile p-benzoyl-L-phenylalanine (Bpa) into the position of Leu22 and have utilized this to identify the adjacent receptor domain. The rat [Tyr10,Bpa22]secretin-27 probe was a fully efficacious agonist, with a potency to stimulate cAMP accumulation by Chinese hamster ovary SecR cells similar to that of natural secretin (EC50 = 68 +/- 22 pM analogue and 95 +/- 25 pM secretin). It bound specifically and with high affinity (Ki = 5.0 +/- 1.1 nM) and covalently labeled the Mr = 57,000-62,000 secretin receptor. Cyanogen bromide cleavage of the receptor yielded a major labeled fragment of apparent Mr = 19,000 that shifted to Mr = 9,000 after deglycosylation. This was most consistent with either of two glycosylated domains within the amino-terminal tail of the receptor. Immunoprecipitation with antibody directed to epitope tags incorporated into each of the candidate domains established that the fragment at the amino terminus of the receptor was the site of labeling. This was further localized to the amino-terminal 30 residues of the receptor by additional proteolysis of this fragment with endoproteinase Lys-C. This provides the first direct demonstration of a contact between a secretin-like agonist and its receptor and will contribute a useful constraint to the modeling of this interaction.

[The expression of ICAM-1 on the keratinocytes in second degree human burn skin]

OBJECTIVE

To investigate the significance of changes in intercellular adhesion molecule-1 (ICAM-1) expression on keratinocytes(KCs) during wound healing of second degree burn.

METHODS

With immunohistochemistry technique, the ICAM-1 expression in second degree burn wounds in patients were investigated at four different postburn periods. The normal skins from 6 burn patients (BNG), the normal skins from 8 healthy volunteers (HVG) and the scar tissues (SG) from 8 patients served as controls.

RESULTS

There was poor expression of ICAM-1 on basal cells in normal skins of healthy volunteers, while the expression of ICAM-1 enhanced in normal skins of burn patients. On basal cells in second degree burn wounds, the expression of ICAM-1 slightly increased in the first week postburn, obviously enhanced in the second week, and in the third or fourth week, the expression continued to keep strong. In addition, the ICAM-1 in KCs showed polar distribution, and the expression of ICAM-1 markedly enhanced on the multilayer KCs in neogenetic epithelium and the positive cells arranged columnarly.

CONCLUSION

The enhanced expression of ICAM-1 on KCs in second degree burn wounds might be related to invasion of inflammatory cells beneath wound. It might play a role in inducing proliferation and migration of KCs and accelerating epithelization.

Epidermal growth factor and its receptor as prognostic indicators in Chinese patients with pancreatic cancer

The expression of epidermal growth factor (EGF) and its receptor (EGFR) was studied immunohistochemically in fifty-seven Chinese patients with primary invasive ductal carcinoma (IDC) of the pancreas. The frequency of expression of EGF and EGFR was 73.7% and 68.4%, respectively. The frequency of their co-expression was 61.4%. No significant relationships were seen between the expression of EGF and its receptor and the patients' age, gender, site of the tumor, stage, and grade. Positive co-expression of EGF and EGFR was significantly associated with the poor prognosis. The median survival of the EGF(-)EGFR(-) group for 17.2 months was longer than that of the EGF(+)EGFR(+) group for 9.7 months (p = 0.02), as well as that of the other groups of EGR(+)EGFR(-), EGF(-)EGFR(+), and EGF(+)EGFR(+) for 9.9 month (p = 0.03). These results suggested that EGF and EGFR were frequently expressed in Chinese patients with IDC of the pancreas. Their co-expression may be a useful prognostic indicator for pancreatic cancer.

In vitro and in vivo reversal of cancer cell multidrug resistance by the semi-synthetic antibiotic tiamulin

A large number of multidrug resistance (MDR) modulators, termed chemosensitizers, have been identified from a variety of chemicals, but most have been proven to be clinically toxic. Low concentrations of the pleuromutilin-derived semi-synthetic antibiotic tiamulin (0.1 to 10 microM) sensitized the three highly resistant P-glycoprotein (Pgp)-overexpressing tumor cell lines P388 (murine lymphoid leukemia), AS30-D (rat hepatoma), CEM (human lymphoblastic leukemia), and the barely resistant AS30-D/S cell lines to several MDR-related anticancer drugs. Flow cytometric analysis showed that tiamulin significantly increased the intracellular accumulation of daunomycin. When compared to reference modulating agents such as verapamil and cyclosporin A, tiamulin proved to be 1.1 to 8.3 times more efficient in sensitizing the resistant cell lines. Moreover, when given i.p. (1.6 microg/mg body weight), tiamulin increased the survival rate of adriamycin-treated mice bearing the P388/ADR25 tumor line by 29%. In the presence of an anticancer drug, tiamulin inhibited both ATPase and drug transport activities of Pgp in plasma membranes from tumor cells. Tiamulin is thus a potent chemosensitizer that antagonizes the Pgp-mediated chemoresistance in many tumor cell lines expressing the MDR phenotype at different levels and displays no toxic effects on contractile tissues at active doses, therefore providing the promise for potential clinical applications.

[A specific property of microvasomotion in the guinea pig cochlea]

OBJECTIVE

To investigate specific property of vasomotion in cochlear microvessels and its response to the endothelium-derived relaxation factor (EDRF).

METHODS

The dynamic changes of cochlea microvessels were observed using intravital microscopy and measured by the microcirculatory image processing system. The frequency and amplitude of vasomotion were analyzed with fast Fourier transform (FFT) according to the diameter changes.

RESULTS

The vasomotion of cochlear arteriole with a small amplitude existed in normal condition. The diameter changed from (10.41 +/- 3.03) microns to (12.29 +/- 1.9) microns with a mean value of (11.2 +/- 2.7) microns. The specific property of vasomotion was characterized by a frequency (0.021 +/- 0.002) Hz and amplitude of (0.37 +/- 0.11) micron. The contraction index was determined as 0.42 +/- 0.17. The vasomotion was significantly enhanced after the administration of EDRF.

CONCLUSION

The vasomotion existed in the cochlea and EDRF can increase the cochlear blood flow by improving the vasomotion.

Comparative study of p53 expression in primary invasive ductal carcinoma of the pancreas between Chinese and Japanese

Previous studies reported different frequencies of p53 expression between Japanese and Americans or Europeans. The present study was designed to clarify whether there is a significant difference in p53 expression and its clinical implications between Chinese and Japanese patients with primary invasive ductal carcinoma (IDC) of the pancreas. p53 expression was studied in 39 Chinese and 47 Japanese patients, and immunostaining with the SAB method was performed using anti-p53 monoclonal antibody (DO-1) in formalin-fixed and paraffin-embedded specimens. Clinical data were analyzed according to the International Union Against Cancer classification. p53 expression was seen in 71.8% of Chinese and in 48.9% of Japanese patients with IDCs of the pancreas (p < 0.05). The Chinese patients were significantly younger than the Japanese ones (p < 0.05), but there were no significant correlations between p53 immunoreactivity and age, gender, stage, and histopathological grade in separate analyses of the Chinese and Japanese patients. A comparison between them showed that in patients younger than 55 and 65 years old, the incidence of p53 expression was markedly lower in Japanese than in Chinese (p < 0.05). In Japanese patients, those with a p53-positive pancreatic cancer had a significantly lower survival rate than those with a p53-negative tumor, but there was no correlation between p53 expression and the prognosis of Chinese patients. The frequency of p53 expression in IDC of the pancreas is higher in Chinese than in Japanese patients, and the effect of p53 expression on prognosis is different between Chinese and Japanese patients.