[Collateral circulation compensation mode in patients with severe bilateral internal carotid artery stenosis/occlusion].

Objective: To investigate the correlation between collateral flow compensation mode and interventional treatment decision in patients with severe bilateral internal carotid artery stenosis/occlusion. Methods: According to the location of internal carotid artery lesions, patients with severe stenosis/occlusion of bilateral internal carotid artery were selected at the Second Affiliated Hospital, Qiqihar Medical University and the Sixth Medical Center of PLA General Hospital from May 2017 to June 2020. Results: A total of 42 patients were finally enrolled and divided into 4 types, including 34 males and 8 females with median age 61±8(48-82)years. The collateral circulation pathways manifested as following modes: anterior communicating artery collateral, posterior communicating artery collateral, ophthalmic artery collateral, posterior cerebral middle cerebral artery pial anastomosis collateral, posterior choroidal artery anterior choroidal artery collateral, external carotid internal carotid artery C4 segment collateral, pericallosal artery anastomosis collateral, dural and pial collateral and neovascularization. Type Ⅰ severe stenosis/occlusion of C1 segment was found in 20 cases (47.6%). There were 5 cases (11.9%) of type Ⅱ severe stenosis/occlusion from C2 to C6 prior to ophthalmic artery branch. Type Ⅲ severe stenosis/occlusion occurred in 2 cases (4.8%) after the split of ophthalmic artery. Type Ⅳ was mixed type in 15 cases (35.7%). Conclusions: The compensatory pathway of collateral circulation is closely related to the lesion location. To explore the compensatory pattern of collateral circulation is helpful for clinicians to accurately analyze the lesion characteristics and guide individualized interventional therapy.

[Association of thallium exposure during pregnancy with maternal blood pressure and hypertensive disorder complicating pregnancy].

Objective: To investigate the association of thallium exposure during pregnancy with pregnant blood pressure changing and hypertensive disorder complicating pregnancy(HDCP). Methods: A total of 3 240 pregnant women who had establish maternal health care manual in Ma'anshan Maternal and Child Health-Care Hospital and met the inclusion and exclusion criteria were included in this study between May 2013 and September 2014.We collected their general demographic characteristics and blood pressure through questionnaire and medical records. Meanwhile we measured serum thallium concentrations by experimental technology. We use multiple logistic regression to analyze the association between thallium exposure during pregnancy and HDCP. Mixed linear model were used to analyze the association between thallium concentration and maternal systolic blood pressure (SBP) or diastolic blood pressure(DBP) in different trimesters Results: The age of 3 240 pregnant woman was (26.61±3.64) years, and the detection rate of HDCP was 5.9%(191).The median (P25, P75) of thallium concentrations in first trimester, second trimester and third trimester were 62.96 (50.79, 77.04), 62.19 (50.87, 75.26), 48.84 (38.00, 66.00) ng/L, respectively. Multiple logistic regression results suggested after adjusting various confounding factors, the risk of HDCP in pregnant women with high concentrations of thallium (>77.04 ng/L) in the first trimester is 1.75 (95%CI:1.01-3.03) times higher than which with low concentrations(<50.82 ng/L). Mixed linear model results suggested there are positive correlation between thallium concentrations with maternal DBP in first trimester (ß=1.12, 95%CI: 0.39-1.85). Conclusion: Exposure to high levels of thallium during first trimester may increase the risk of HDCP, and the exposure of thallium may be effective to DBP of pregnant.

[Adverse maternal and infant health effects caused by thallium exposure during pregnancy].

Thallium is a highly toxic heavy metal. The adverse maternal and infant health effects caused by thallium exposure during pregnancy have also attracted more and more scholars' attention. This study focused on the sources of thallium exposure and its influencing factors, the association between thallium exposure during pregnancy and pregnancy complications and adverse birth outcomes in newborns, the effects of thallium exposure during pregnancy on children's growth and development after birth. In terms of potential mechanisms, the related research progress was reviewed in this study, which could provide a new basis for further research on the harm, prevention and control of thallium exposure during pregnancy.

[The relationship of maternal and umbilical cord blood zinc level associated with newborn birth weight: a birth cohort study].

Objective: To study serum zinc level in pregnancy and umbilical cord blood and their association with newborn birth weight. Methods: Pregnant women accepting obstetric examination in Ma'anshan Maternal and Child Care Center were recruited from May 2013 to September 2014. The follow up was conducted during their first, second and third trimesters of pregnancy and the self-designed questionnaire was used to collect information of social and demographic characteristics. Blood samples in the first, second pregnancy period and umbilical cord blood samples were collected and serum concentrations of zinc were assayed. 3 239 mother-infant entered the final analysis. We divided serum zinc level into low (P(75)) groups according to their exposure concentrations at each trimesters. Non-conditional multivariate logistic regression model was conducted to evaluate the association between serum zinc level in first, second trimesters of pregnancy and umbilical cord blood with small for gestational age (SGA) and large for gestational age (LGA). Results: Serum zinc level in P(50) (P(25)-P(75)) during the first, second trimesters and cord blood were 1 016.18 (907.09-1 145.60), 813.36 (732.47-897.89) and 903.44 (808.71-1 015.64) µg/L, respectively. The prevalence of zinc deficiency during the first, second trimesters and cord blood were 1.5% (44/2 957), 15.9% (492/3 087) and 6.5% (176/2 707), respectively. The prevalence of total SGA and LGA were 9.7% (313/3 239) and 16.5% (536/3 239), respectively. Compared to high-level serum zinc group, the risk of SGA (OR (95%CI) in low-level serum zinc group during first trimesters was 1.51 (1.05-2.19)). Serum zinc level among second pregnancy period and umbilical cord blood had no statistically significant effect on SGA and LGA (both P values >0.05). Conclusion: Zinc nutritional status of pregnant women in Ma'anshan city was at a good level. The low serum zinc level in first trimester increased the risk of SGA.

[Study on the relationship of thallium exposure and outcomes of births].

Objective: To investigate the relationship of thallium exposure and outcomes of births. Methods: A total of 3 236 mothers who had visited in Ma'anshan Maternal and Child Health-Care Hospital between May 2013 and September 2014 were included in this study and their thallium concentrations measured from samples of maternal and umbilical cord blood by inductively coupled plasma mass spectrometry. The results were correlated and evaluated with birth outcomes of the infants, using the multiple linear regression method. Results: The median (P(25)-P(75)) of thallium levels in first trimester, second trimester and umbilical cord blood were 61.7 (50.8-77.0), 60.3 (50.8-75.2) and 38.5 (33.6-44.1) ng/L, respectively. After adjustment for potential confounders, the thallium levels showed an inversely significant association with birth head circumference (unstandardized ß coefficient=-0.41, 95%CI: -0.76- -0.06) in the first trimester blood, and associated with reduced birth length (unstandardized ß coefficient=-0.65, 95%CI: -1.25- -0.05) in umbilical cord blood. However, there appeared no significantly associations with birth weight, length and head circumference (P>0.05) in second trimester. On stratification by sex, in girls but not in boys, the thallium levels were adversely associated with birth head circumference (unstandardized ß coefficient=-0.53, 95%CI: -1.05--0.01) in the first trimester and were associated with decreased birth weight (unstandardized ß coefficient=-277.08, 95%CI: -485.13- -69.03) and length (unstandardized ß coefficient=-1.39, 95%CI: -2.26- -0.53) in umbilical cord blood thallium. Conclusions: Thallium exposure appeared a gender difference in newborn birth outcomes. In the first trimester, it was negatively associated with the birth head circumference, in the umbilical cord blood, and reduced birth weight and length in girls.

Predictive factors for inadequate colon preparation before colonoscopy.

BACKGROUND: It could be helpful to ascertain which patients are at risk of poor bowel preparation prior to performing sedated colonoscopy. The aim of the present study was to identify the predictive factors for poor colon preparation prior to colonoscopy. METHODS: A prospective study was performed at Kaohsiung Chang Gung Memorial Hospital, Taiwan, from September 2011 to May 2013. Patient characteristics, food consumed within 2 days of colonoscopy, volume of polyethylene glycol (PEG) solution, interval between completing PEG and examination, number of bowel movements, and character of the last stool were evaluated. RESULTS: Seven hundred and three patients were enrolled (mean age 50.3 ± 11.6 years, 43 % female). In univariate analysis, character of the last stool (<0.001), body weight (p = 0.007), body mass index (p = 0.047), waist circumference (p = 0.008), buttock girth (p = 0.016), meal residue score (<0.001), and interval between end of PEG and colonoscopy (p = 0.01) were related to inadequate colon preparation. In multivariate analysis, waist circumference (p < 0.001), meal residue score (p < 0.001), and characteristics of last stool (p < 0.001) were variables that predicted poor colon preparation. CONCLUSIONS: Patients who have consumed a high residue diet and/or who report that their last stool is semisolid are likely to have poor bowel preparation, and consideration could be given to rescheduling the examination.

Note: Decoupling design for high frequency piezoelectric ultrasonic transducers with their clamping connections.

This work presents the flexure-mechanism based decoupling design between high frequency piezoelectric ultrasonic transducers and their clamping connections to improve ultrasonic energy transmission efficiency. The ring, prismatic beam, and circular notched hinge based flanges were presented, and the crucial geometric dimensions of the transducers with the flexure decoupling flanges were determined. Finite element analysis (FEA) was carried out to investigate the dynamic characteristics of the transducers. Finally, experiments were conducted to examine and verify the effects of the proposed decoupling flanges. FEA and experimental results show that smaller frequency deviations and larger tip displacement amplitudes have been achieved by using the transducers with the flexure flanges compared with the transducer with a rigid ring-type flange, and thus the ultrasonic transmission efficiency can be improved through the flexure flanges.

Role of hepatitis C virus substitutions and interleukin-28B polymorphism on response to peginterferon plus ribavirin in a prospective study of response-guided therapy.

Recent studies have indicated that amino acid (aa) substitutions in the core region and NS5A interferon sensitivity-determining region (ISDR) of hepatitis C virus (HCV) as well as genetic polymorphisms in the interleukin-28B (IL-28B) locus affect the outcome of interferon (IFN)-based therapies. We aimed to investigate the role of these factors on response to peginterferon plus ribavirin in a prospective study of response-guided therapy. The aa sequences in core region and ISDR and rs12979860 genotypes were analysed in 115 HCV-1 patients. The treatment was 24 weeks for patients achieving a rapid virological response (RVR), 48 weeks for those with an early virological response (EVR) and early terminated in those without an EVR. A sustained virological response (SVR) was achieved in 82% of 34 RVR patients, 45% of 74 EVR patients and 0% of seven non-EVR patients. Logistic regression analysis showed that ISDR mutation (≥2) [odds ratio(OR): 6.024], double core 70/91 mutations (OR: 0.136), and platelet counts≥15×10(4) /µL (OR: 3.119) were independent pretreatment factors associated with SVR. Apart from rs12979860 CC genotype, low viral load and ISDR mutation (≥2) were significant factors predictive of RVR. Combination of rs12979860 genotype and baseline viral characteristics (viral load and core/ISDR mutations) could predict RVR and SVR with positive predictive value of 100% and 91%, and negative predictive value of 80% and 54%, respectively. In conclusion, pretreatment screening rs12979860 genotype and aa substitutions in the core region and ISDR could help identifying patients who are good candidates for peginterferon plus ribavirin therapy.

Correlation between microRNA-34a levels and lens opacity severity in age-related cataracts.

PURPOSE: MicroRNA 34a (miR-34a) is involved in regulating tissue senescence. However, the role of miR-34a in age-related cataracts is unclear. In this study, we evaluated the correlations among the severity of lens opacity, patient age, and miR-34a expression level in the lens epithelium of age-related cataracts for clarifying the role of miR-34a in the lens senescence. METHODS: This study was carried as a case control study in the Department of Ophthalmology, Taipei Veterans General Hospital, Taiwan. We recorded age of each patient at the time of their cataract surgery and information regarding lens opacity according to a modified version of the Lens Opacities Classification System III. Correlations among age, lens opacity, and miR-34a expression levels were evaluated. RESULTS: This study evaluated 110 patients with a mean age of 73.19 years (SD±10.2). Older patients had higher nuclear cataract (NC), cortical (C), and posterior subcapsular cataract (P) scores (one-way analysis of variance (ANOVA), P<0.05). miR-34a expression levels were significantly different between each age group (ANOVA post hoc Bonferroni's test, P<0.001), and there were moderate correlations between high NC, C, and P cataract scores and high miR-34a levels (Pearson correlation coefficient; R=0.606, 0.575, and 0.515, respectively). CONCLUSIONS: The current study demonstrated positive correlations between high miR-34a levels and high lens opacity severity in NC, C, or P cataracts. These results suggest that miR-34a expression has a role in lens senescence.

Raf activation by Ras and promotion of cellular metastasis require phosphorylation of prohibitin in the raft domain of the plasma membrane.

Prohibitin (PHB) is indispensable for Ras-induced Raf-1 activation, cell migration and growth; however, the exact role of PHB in the molecular pathogenesis of cancer metastasis remains largely unexamined. Here, we found a positive correlation between plasma membrane-associated PHB and the clinical stages of cancer. The level of PHB phosphorylated at threonine 258 (T258) and tyrosine 259 (Y259) in human cancer-cell membranes correlated with the invasiveness of cancer cells. Overexpression of phosphorylated PHB (phospho-PHB) in the lipid-raft domain of the cell membrane enhanced cell migration/invasion through PI3K/Akt and Raf-1/ERK activation. It also enhanced epithelial-mesenchymal transition, matrix metalloproteinase-2 activity and invasiveness of cancer cells in vitro. Immunoprecipitation analysis demonstrated that phospho-PHB associated with Raf-1, Akt and Ras in the membrane and was essential for the activation of Raf-1 signaling by Ras. Mice implanted with cancer cells stably overexpressing PHB in the plasma membrane showed enlarged cervical tumors, enhanced metastasis and shorter survival time compared with mice implanted with cancer cells without PHB overexpression. Dephosphorylation of PHB at T258 by site-directed mutagenesis diminished the in vitro and in vivo effects of PHB. These results suggest that increase in phospho-PHB T258 in the raft domain of the plasma membrane has a role in the Ras-driven activation of PI3K/Akt and Raf-1/ERK-signaling cascades and results in the promotion of cancer metastasis.

Intermediate outcomes of Ahmed glaucoma valve surgery in Asian patients with intractable glaucoma.

OBJECTIVE: To evaluate the efficacy and safety of Ahmed glaucoma valve (AGV) implantation in Asian patients with refractory glaucoma. METHODS: The study was a retrospective interventional case series conducted at a single institution between January 2004 and January 2006. The study population included 91 patients (91 eyes). RESULTS: A total of 70 patients were successfully treated (74.5%). Postoperatively, the median intraocular pressures declined significantly to 13 mm Hg (interquartile range: 10-20 mm Hg) on day 1 (P<0.001) and 17 mm Hg (interquartile range: 12-19 mm Hg) at the last follow-up examination (P<0.001). The cumulative probability of success according to Kaplan-Meier life-table analysis was 74% at 12 months and 43% at 2 years. Hazard of failure increased slightly with age, HR: 1.03 (95% confidence interval (CI)=1.00-1.05; P=0.044). The most common complication was hyphaemia at 12.77%. There were no serious complications involving loss of visual acuity or sight. CONCLUSIONS: AGV implantation is an acceptable treatment for refractory glaucoma in high-risk patients with few additional options.

Effect of solvent state and isothermal conditions on gelation of methylcellulose hydrogels.

In this study, thermal behavior of aqueous solutions of methyl cellulose (MC) at a constant temperature of 50 degrees C was analyzed. Various samples were studied for two consecutive heating-cooling cycles. The experiments with the solutions prepared using cold de-ionized (DI) water showed that the rate of gelation was higher for higher MC concentrations. However, the rate was slower during the first heating-cooling cycle than during the second cycle. The possible reasons behind such observations are discussed. Various MC solutions prepared using hot DI water were studied for understanding the role of the solvent state in the isothermal gelation process. The gelation of these MC solutions started at a lower MC concentration and resulted in a higher gelation rate. The gelation mechanism responsible for such effects is explored and presented. Finally, a gel-indexing method is proposed to provide a quantitative measure of the gelation state of all the MC gels.

Sweet hyperopia: refractive changes in acute hyperglycemia.

PURPOSE: A prospective study was performed to evaluate refractive and ocular biometric changes in acute hyperglycemic status in patients with diabetes mellitus. METHODS: From January to August 2002, 48 eyes of 24 patients with persistent diabetes and a plasma glucose level>or=17 mmol/L or HbA1c>or=10.0% on admission were enrolled in this prospective study. Upon admission to Tri-Service General Hospital in Taipei, Taiwan, these patients underwent intensive glycemic control. The basic ophthalmic examinations, including visual acuity, intraocular pressure measurement, slit lamp, and fundus examinations, were conducted. The ocular parameters including refraction, anterior chamber depth, lens thickness, axial length, mean keratometry, and thinnest corneal thickness were evaluated by A-mode scan and Orbscan II. Each patient underwent clinical follow-up visits at 1, 2, and 4 weeks after the acute hyperglycemic episode. RESULTS: Of the 24 patients, 18 were male and 6 were female. The mean age of the patients was 55 years (range: 38 to 69). Comparing the refractive status on admission and at week 4, the authors found that 8 cases (16 eyes, 33%) showed hyperopia during hyperglycemia (+1.9+/-0.8 D), but in the other 16 cases (32 eyes, 67%), there were no significant changes. In addition, there were also no significant changes in anterior chamber depth, lens thickness, axial length, thinnest corneal thickness, or mean keratometry in the follow-up period. CONCLUSIONS: Transitory hyperglycemia produces hyperopia. The alteration in refractive index in the lens may contribute to the hyperopic change, but no change of ocular biometrics in lens or cornea is observed.

Enhancement of the immunity to foot-and-mouth disease virus by DNA priming and protein boosting immunization.

Subunit vaccination is effective in eliciting humoral responses to a variety of viral antigens, however, it has not generated persistent protective immunity to foot-and-mouth disease virus (FMDV). In this study, we observed that priming mice with a DNA plasmid encoding VP1 of the FMDV O/Taiwan/97 capsid protein followed by boosting with a VP1 peptide conjugate (P29-KLH) resulted in production of not only high titers of antibodies but also antibodies with FMDV neutralizing activities. Moreover, the mice immunized in this manner cleared the virus from their sera in FMDV challenge experiments. Mice subjected to DNA plasmid priming and P29-KLH protein boosting had relatively higher ratio of IgG2a/IgG1 than those primed and boosted with P29-KLH conjugate. Addition of an oligodeoxynucleotide (ODN) containing immunostimulatory cytosine-phosphate-guanosine (CpG) motifs to P29-KLH conjugate also induced a higher ratio of IgG2a/IgG1 and significantly higher titer of neutralizing antibodies. These results indicate that treating animals with DNA plasmids priming and FMDV antigen(s) boosting may elicit immunity to FMD and this immune response may be augmented by CpG ODN.

Enhanced oxidative stress and accelerated cellular senescence in glucose-6-phosphate dehydrogenase (G6PD)-deficient human fibroblasts.

Glucose-6-phosphate dehydrogenase (G6PD) is involved in the generation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) and the maintenance of the cellular redox balance. The biological effects of G6PD deficiency in nucleated cells were studied using G6PD-deficient human foreskin fibroblasts (HFF). In contrast to that of normal HFF, the doubling time of G6PD-deficient cells increased readily from population doubling level (PDL) 15 to 63. This was accompanied by a significant increase in the percentage of G(1) cells. The slow-down in growth preceded an early entry of these cells into a nondividing state reminiscent of cellular senescence. These cells exhibited a significant increase in level of senescence-associated beta-galactosidase (SA-beta-gal) staining. The importance of G6PD activity in cell growth was corroborated by the finding that ectopic expression of active G6PD in the deficient cells prevented their growth retardation and early onset of senescence. Mechanistically, the enhanced fluorescence in dichlorofluorescin (H(2)DCF)-stained G6PD-deficient cells suggests the possible involvement of reactive oxygen species in senescence. Taken together, our results show that G6PD deficiency predisposes human fibroblasts to retarded growth and accelerated cellular senescence. Moreover, G6PD-deficient HFF provides a useful model system for delineating the effects of redox alterations on cellular processes.

Cellular glucose-6-phosphate dehydrogenase (G6PD) status modulates the effects of nitric oxide (NO) on human foreskin fibroblasts.

Glucose-6-phosphate dehydrogenase (G6PD) plays an important role in cellular redox homeostasis, which is crucial for cell survival. In the present study, we found that G6PD status determines the response of cells exposed to nitric oxide (NO) donor. Treatment with NO donor, sodium nitroprusside (SNP), caused apoptosis in G6PD-deficient human foreskin fibroblasts (HFF1), whereas it was growth stimulatory in the normal counterpart (HFF3). Such effects were abolished by NO scavengers like hemoglobin. Ectopic expression of G6PD in HFF1 cells switched the cellular response to NO from apoptosis to growth stimulation. Experiments with 1H-¿1,2,4oxadiazolo¿4, 3-aquinoxalin-1-one and 8-bromo-cGMP showed that the effects of NO on HFF1 and HFF3 cells were independent of cGMP signalling pathway. Intriguingly, trolox prevented the SNP-induced apoptosis in HFF1 cells. These data demonstrate that G6PD plays a critical role in regulation of cell growth and survival.

Human neutrophils secrete gelatinase B in vitro and in vivo in response to endotoxin and proinflammatory mediators.

Bacterial sepsis is characterized by a systemic inflammatory state, with activation of numerous cell types. Phagocytes participate in this phenomenon by secreting various proinflammatory cytokines and enzymes. Matrix metalloproteinases (MMPs) such as gelatinases are produced by phagocytes and are thought to play an important role in processes of cell transmigration and tissue remodeling. In this work, we show that endotoxin (lipopolysaccharide [LPS]) and other inflammatory mediators, such as tumor necrosis factor (TNF), interleukin-8, and granulocyte colony-stimulating factor, induce a rapid (within 20 min) release of gelatinase-B (MMP-9) zymogen in whole human blood, as determined by gelatin zymography. The polymorphonuclear neutrophil was identified as the cell responsible for this rapid secretion, as a result of the release of preformed enzymes stored in granules. Normal human subjects given LPS intravenously showed a similar pattern of proMMP-9 secretion, with maximum plasma levels reached 1.5 to 3 h after LPS administration (P = 0.0009). Prior administration of TNF receptor:Fc, a potent TNF antagonist, to subjects given LPS, only partially blunted the release of proMMP-9 (P = 0.033). Ibuprofen, a cyclooxygenase inhibitor, did not alter this pattern of release. Increased levels of proMMP-9 and proMMP-2, as well as activated forms of MMP-9, were found in plasma from two patients with gram-negative sepsis. The levels of MMPs paralleled the severity of clinical condition and a marker of the severity of sepsis, plasma procalcitonin. These data indicate that MMPs are released in whole blood in response to various inflammatory mediators and that they could serve as sensitive and early markers for cell activation during the course of bacterial sepsis.

Enhanced expression of tissue inhibitor of metalloproteinase-2 (TIMP-2) in the stroma of breast carcinomas correlates with tumor recurrence.

The 72-kDa (MMP-2, gelatinase A) and the 92-kDa (MMP-9, gelatinase B) matrix metalloproteinases have been associated with tumor cell invasion and metastasis. Immunohistological staining of MMP-2 and MMP-9, basal lamina collagen IV and TIMP-2 were performed on frozen sections of 83 invasive breast carcinomas. MMP-2 and MMP-9 were associated with neoplastic cell plasma membrane in 72% of cases and exhibited inter-tumoral variability of staining intensity. MMP-2 and MMP-9 staining was not correlated with presence of metastases at time of diagnosis or with disease outcome. TIMP-2 was detected in the peri-tumoral stroma and was present in 87% of cases. Residual benign breast tissue was negative for TIMP-2 staining. Neoplasms with diffuse TIMP-2 staining (24%) recurred significantly more frequently (75% recurred) than cases with focal (42% recurred) or absent (27% recurred) TIMP-2. Presence of collagen IV was negatively correlated with gelatinase staining. We conclude that up-regulation of MMP-2 and MMP-9 expression in breast tumor cells is reciprocally correlated to collagen IV staining. Clinical outcome, however, is more closely related to the presence of TIMP-2 than the corresponding MMPs. Enhanced TIMP-2 expression, therefore, may denote a stromal response to tumor invasion, indicative of aggressive behavior in a subset of breast carcinomas.

Immunohistochemical localization of matrix metalloproteinase 2 and its specific inhibitor TIMP-2 in neoplastic tissues with monoclonal antibodies.

Matrix metalloproteinase-2 (MMP-2), synthesized as a 631 amino-acid proenzyme, is activated by cleavage of the first 80 amino acids and naturally inhibited by tissue inhibitor of metalloproteinase-2 (TIMP-2). We report here the production of MAbs against MMP-2 and TIMP-2 and their use in localizing the respective antigens on tumor tissues. The anti-MMP-2 MAb recognized the latent and activated MMP-2 mutant protein (mutein) with C-terminal deletion at amino acid 425, indicating that both N- and C-terminal amino acids of MMP-2 are not important for its binding. The binding study of anti-TIMP-2 MAb, using several C-terminally truncated TIMP-2 muteins, showed that the amino acids 111-126 of TIMP-2 are essential for the binding of this antibody. Besides their respective antigens, both MAbs also recognized the MMP-2/TIMP-2 complex. On frozen sections of breast tumor, anti-MMP-2 MAb stained mainly tumor-cell cytoplasm with varying intensity, while anti-TIMP-2 MAb gave a stromal staining of varying intensity and a weak or absent staining of tumor-cell cytoplasm, suggesting different localization of the proteins in these tumors. In addition, in 1/3 of the breast cases both antibodies also localized on tumor-cell membranes. Similar cytoplasmic and stromal but not membrane staining patterns were observed in colon, gastric, endometrial, squamous-cell, prostatic and ovarian carcinoma as well. Since MMP-2 degrades type-IV collagen, the major component of basement membranes, the differences between MMP-2 and TIMP-2 levels and localization in individual tumors may relate to the invasiveness of the tumor and thus provide predictive information. However, this aspect could not be discussed in this study because no biological and clinical parameters such as lymph-node involvement or Dukes' stage of the tumors were available.

Conformational changes of human beta 1 thyroid hormone receptor induced by binding of 3,3',5-triiodo-L-thyronine.

To understand the structural basis in the hormone-dependent transcriptional regulation of human beta 1 thyroid hormone receptor (h-TR beta 1), we studied the conformational changes of h-TR beta 1 induced by binding of 3,3',5-triiodo-L-thyronine (T3). h-TR beta 1 was treated with trypsin alone or in the presence of T3, thyroid hormone response element (TRE) or T3 together with TREs. Without T3, h-TR beta 1 was completely digested by trypsin. Binding of TREs had no effect on the tryptic digestion pattern. However, T3-bound h-TR beta 1 became resistant to tryptic digestion and yielded trypsin-resistant peptide fragments with molecular weight of 28,000 and 24,000. Chymotryptic digestion also yielded a T3-protected 24 Kd peptide fragment. Using anti-h-TR beta 1 antibodies and amino acid sequencing, the 28 Kd fragment was identified to be Ser202-Asp456. The 24 Kd tryptic fragments were found to be Lys239-Asp456 and Phe240-Asp456. The 24 Kd chymotryptic fragment was identified to be Lys235-Asp456. The structural changes as a result of T3 binding could serve as a transducing signal to modulate the gene regulating activity of h-TR beta 1.