Role of tyrosine phosphorylation in thrombin-induced endothelial cell contraction and barrier function

Thrombin-induced endothelial cell (EC) barrier dysfunction is highly dependent upon phosphorylation of serine and threonine residues present on myosin light chains (MLC) catalyzed by a novel EC myosin light chain kinase (MLCK) isoform. In this study, we examined the participation of tyrosine protein phosphorylation in EC contraction, gap formation and barrier dysfunction. We first determined that thrombin significantly increases protein tyrosine kinase activity and protein tyrosine phosphorylation in bovine pulmonary artery EC. Tyrosine kinase inhibitors, genistein and 2,5 DHC, reduced EC tyrosine kinase activities, however, only genistein significantly attenuated thrombin-mediated increases in albumin clearance and reductions in transendothelial electrical resistance. Similarly, genistein but not 2,5 DHC, decreased basal and thrombin-induced Ca2+ increases and MLC phosphorylation in the absence of alterations in Type 1 or 2A serine/threonine phosphatase activities. Immunoprecipitation of the EC MLCK isoform revealed a 214 kD immunoreactive phosphotyrosine protein and genistein pretreatment significantly reduced MLCK activity in MLCK immunoprecipitates. Although thrombin induced the translocation of p60src from the cytosol to the EC cytoskeleton, a detectable increase in the level of MLCK tyrosine phosphorylation was not noted after thrombin challenge. Taken together, our data suggest that genistein-sensitive tyrosine kinase activities are involved in thrombin-mediated EC MLCK activation, MLC phosphorylation, and barrier dysfunction.

A study of the relationship between caries activity and the status of dental caries: application of the Dentocult LB method

OBJECTIVE

To clarify the relationship between caries activity and the status of caries of primary teeth and the relationship between the quantity of Lactobacillus in the oral cavity and the status of dental caries.

METHODS

The status of caries of primary teeth in 164 children ages 3 to 5 was examined. Caries incidence, mean DFT, and Caries Severity Index (CSI) were calculated. Based on the quantity of Lactobacilli in the saliva of preschool children detected with the Dentocult LB method of caries activity, four grades were classified: Grade 0 = 10(3) CFU/mL, Grade I = 10(4) CFU/mL, Grade II = 10(5) CFU/mL, and Grade III = 10(6) CFU/mL.

RESULTS

The results showed that 34.15% of the children had caries status beyond Grade I. There were significant differences of caries status, DFT, and CSI among different grades, all of which increased with grades. There was a high correlation between grades and caries incidence, DFT, and CSI in the 164 preschool children.

CONCLUSION

As a Caries Activity Test (CAT), detection of Lactobacilli may reveal the status of dental caries and provide valuable information for the prevention and treatment of dental caries.

Phospholipase D activation in endothelial cells is redox sensitive

Reactive oxygen species (ROS) are implicated in the pathophysiology of a number of vascular disorders, including atherosclerosis. Recent studies indicate that ROS modulate signal transduction in mammalian cells. Previously, we have shown that ROS (hydrogen peroxide, fatty acid hydroperoxide, diperoxovanadate, and 4-hydroxynonenal) enhance protein tyrosine phosphorylation and activate phospholipase D (PLD) in bovine pulmonary artery endothelial cells (BPAECs). In the present study, our aim was to investigate the role of exogenous thiol agents on ROS-induced PLD activation in conjunction with the role of cellular thiols--glutathione (GSH) and protein thiols--on PLD activation and protein tyrosine phosphorylation. Pretreatment of BPAECs with N-acetyl-L-cysteine (NAC) or 2-mercaptopropionylglycine (MPG) blocked ROS-induced changes in intracellular GSH and PLD activation. Also, pretreatment with NAC attenuated diperoxovanadate-induced protein tyrosine phosphorylation. Pretreatment of BPAECs with diamide or L-buthionine-(S,R)-sulfoximine (BSO), agents that lower intracellular GSH and thiols, enhanced PLD activity. Furthermore, NAC blocked diamide- or BSO-mediated changes in GSH levels, PLD activity, and protein tyrosine phosphorylation. NAC also attenuated diamide-induced tyrosine phosphorylation of proteins between 69 and 118 KDa. These results support the hypothesis that modulation of thiol-redox status (cellular nonprotein and protein thiols) may contribute to the regulation of ROS-induced protein tyrosine phosphorylation and PLD activation in vascular endothelium.

[Primary experience in inframammary crease reconstruction]

OBJECTIVE

To improve the result of augmentation mammaplasty.

METHODS

The authors selected 15 patients whose primary breast volume was less than 70 ml. During augmentation mammaplasty on these patients, the inframammary creases were reconstructed by lifting and fixation under the pectorales major. The paper elaborated on the principle, design and method of the operation.

RESULTS

Postoperative follow-up for 6 to 12 months showed good results.

CONCLUSION

This method is simple, of rational design and leaving no scar on the skin.

The relationship between caries activity and the status of dental caries--application of the Dentocult SM method

OBJECTIVE

To study the relationship between caries activity and the status of dental caries in preschool children using a caries activity test (CAT).

MATERIALS AND METHODS

The status of primary tooth caries in 229 children ages 3 to 5 was examined. Caries incidence, DFT, and caries severity index (CSI) were calculated. Based on the quantity of Streptococcus mutans in the oral cavity detected with Dentocult SM, a caries activity test, four grades of caries activity were classified: Grade 0 (< 10(4) colony-forming units/mL), Grade I (10(4)-10(5) CFU/mL), Grade II (10(5)-10(6) CFU/mL), and Grade III (> 10(6) CFU/mL).

RESULTS

The results showed that 79.48% children had Grade I or higher caries severity. Significant differences of caries activity were found among different grades, which were highly correlated with caries incidence, DFT, and CSI (r = 0.22216, 0.31212, and 0.32276, respectively).

CONCLUSIONS

As a CAT, Dentocult SM is a reliable method for measuring the status of dental caries in preschool children. It is also a valuable tool in the prevention and treatment of dental caries.

[Malignant mixed mesodermal tumors of the ovary: a clinical analysis of 12 cases]

OBJECTIVE

To explore the clinical characteristics, treatment and prognostic factors of patients with malignant mixed mesodermal tumors of the ovary (MMMTO).

METHODS

Clinical data of 12 patients with MMMTO between 1983-1997 were reviewed retrospectively. The median age of the patients was 50.7 years. According to FIGO staging system (1985), there were 4 cases in stage II, 6 in stage III and 1 in stage IV. Staging was unclear in the remaining case. Heterologous and homologous elements were present in the primary ovarian tumors in 4 and 8 of the 12 patients, respectively. All patients received cytoreductive surgery. Eleven of them received postoperative chemotherapy and 3 of these eleven patients received additional radiotherapy of pelvic field.

RESULTS

The median survival of this group of 12 patients was 24 months. The 2- and 5-year survival rate was 33.3% (4/12) and 8.33% (1/12), respectively. The 2-year survival rate of stage II and III was 50% and 33.3% respectively. One patent in stage IV died within 1 year. Four of the 8 patients with homologous histology survived over 2 years while all the 4 cases with heterologous histology died within 2 years. Five of the 11 patients (45.5%) received combination therapy died within 1 year while 1 patient treated with surgery alone died within 6 months.

CONCLUSIONS

The prognosis of MMMTO is rather poor. Surgery combined with chemotherapy and/or radiotherapy seems to be a better choice of approach. The histological tpyes of tumor and stage of the disease are related to prognosis.

Regulation of endothelial cell myosin light chain phosphorylation and permeability by vanadate

The involvement of tyrosine protein phosphorylation in the regulation of endothelial cell (EC) contraction and barrier function is poorly understood. We have previously shown that myosin light chain (MLC) phosphorylation catalyzed by a novel 214 kDa EC myosin light chain kinase (MLCK) isoform is a key event in EC contraction and barrier dysfunction [Garcia et al. (1995): J Cell Physiol 163:510-522; Garcia et al. (1997): Am J Respir Cell Mol Biol 16:487-491]. In this study, we tested the hypothesis that tyrosine phosphatases participate in the regulation of EC contraction and barrier function via modulation of MLCK activity. The tyrosine phosphatase inhibitor, sodium orthovanadate (vanadate), significantly decreased electrical resistance across bovine EC monolayers and increased albumin permeability consistent with EC barrier impairment. Vanadate significantly increased EC MLC phosphorylation in a time-dependent manner (maximal increase observed at 10 min) and augmented both the MLC phosphorylation and permeability responses produced by thrombin, an agonist which rapidly increases tyrosine kinase activities. The vanadate-mediated increase in MLC phosphorylation was not associated with alterations in either phosphorylase A Ser/Thr phosphatase activities or in cytosolic [Ca2+] but was strongly associated with significant increases in EC MLCK phosphotyrosine content. These data suggest that tyrosine phosphatase activities may participate in EC contractile and barrier responses via the regulation of the tyrosine phosphorylation status of EC MLCK.

[Determination of posterior lens capsule status in traumatic cataract with B-ultrasonography]

OBJECTIVE

To determine the status of posterior lens capsule in traumatic cataract with B-ultrasonography.

METHODS

44 eyes of traumatic cataract were studied. The integrity of posterior lens capsule was evaluated with B-ultrasonography before surgery. Cataract extraction was performed under microscope and the status of posterior lens capsule was recorded.

RESULTS

21 eyes showed complete posterior lens capsule in B-ultrasonography. Of them, 19 eyes (90.5%) were confirmed by surgery. Other 23 eyes with posterior lens rupture determined before operation were all confirmed by surgery (100.0%).

CONCLUSION

B-ultrasonography is helpful in evaluating the integrity of posterior lens capsule and choosing the strategy of surgery.

[Effect of xueling on relating substances of renal hypertension in rats]

Xueling(p.o.) obviously reduces the aldosterone content of renal hypertension rats, but not affecting markedly the endothelin, atrial natriuretic factor, calcitonin gene-related peptide, thromboxane B2 and 6-keto-prostaglandin F1 alpha. The content reduction of aldosterone is one of the mechanisms to lower blood pressure.

[Differentiation of original plants of xihuangcao by using random amplified polymorphic DNA (RAPD) markers]

Four original plants of Xihuangcao have been differentiated from each other by random amplified polymorphic DNA polymorphism. The results show that RAPD technique is an effective method for identification and quality study of Chinese medicinal materials.

Phylogeny and biogeography of Aralia sect. Aralia (Araliaceae)

Aralia sect. Aralia (Araliaceae) consists of approximately eight species disjunctly distributed in Asia and North America. Phylogenetic and biogeographic analyses were conducted using sequences of the internal transcribed spacer regions of the nuclear ribosomal DNA. Aralia racemosa from eastern North America was sister to A. californica from western North America. Aralia cordata from eastern Asia did not form a species-pair relationship with the eastern North American A. racemosa. The two subspecies of A. racemosa formed a monophyletic group. Biogeographic analyses showed a close area relationship between eastern North America and western North America. The Himalayas were cladistically basal and eastern Asia was placed between the Himalayas and North America. The biogeographic analysis supported the origin of the eastern Asian and eastern North American disjunct pattern in Aralia sect. Aralia via the Bering land bridges. Comparisons with results of phylogenetic analyses of other genera suggested that (1) the floristic connection between eastern North America and western North America may be stronger than previously thought; and (2) the biogeographic patterns in the Northern Hemisphere are complex. Furthermore, a lack of correlation between sequence divergence values and phylogenetic positions was observed, suggesting the importance of a phylogenetic framework in biogeographic analyses.

[Protective role of endogenous nitric oxide to microcirculation of rats during burn shock]

OBJECTIVE

To investigate the role of nitric oxide (NO) in burn shock.

METHODS

A model of 40% TBSA deep II burn injury in rats was used. The effects of L-NAME, the inhibitor of NO synthase, and L-Arg, the precursor of NO synthesis, on the mean arterial pressure (MAP), microcirculation of muscle, concentration of NO2(-)/NO3(-) in plasma and the survival time of animals were observed.

RESULTS

The results showed that the synthesis of nitric oxide was increased significantly, accompanied with the decrease of MAP and the disturbances of microcirculation of muscle after burn. L-NAME inhibited the decrease of MAP, but aggravated the disturbances of microcirculation and shortened the survival time of animals, while L-Arg produced the contrary effects.

CONCLUSION

The results indicated that the large amount of NO in blood after burn may play an early protective role to injury.

Identification and cloning of a truncated isoform of the cardiac sodium-calcium exchanger in the BALB/c mouse heart

A truncated isoform of the cardiac sodium-calcium exchanger (NCX1) was identified and cloned from BALB/c mouse heart. This cDNA clone has an AATAAA polyadenylation signal in the 3' untranslated region that caused the 3344-bp clone to stop at a premature termination site and encode for a 940-amino acid (AA) protein, in contrast to the wild-type C57BL/6 mouse, which has a 970-AA protein. Comparing the predicted AA sequence of NCX1 between the two mouse strains by hydropathic plot, we found that the BALB/c NCX1 protein has only 11 extracellular domains, missing one domain at the COOH terminal, while C57BL/6 mice have 12 extracellular domains, similar to other species. Using the mouse mapping gene panel BCB, the NCX1 gene was mapped to the distal end of mouse chromosome 17 (51.3 cM), confirming the data published from the rat probe.

[Fate of massive retrieved human bone allografts]

OBJECTIVES

To study retrieved massive human allograft specimen after they had been in situ for four to sixty-five months, and to investigate the changes union, bone replacement and degradation of articular cartilage.

METHOD

BMP gene expression in the specimen was also studied with in situ hybridization, immunohistochemical methods, and the observations were correlated with the clinical and isotope scan date.

RESULT

The union between the allograft and the host was achieved by the formation of an external callus derived from the cortex of the host. New bone replacement took place slowly. Analysis of the articular cartilage revealed evidence that some chondrocytes had survived in non bearing area of the articular. The expression of BMP in the surface of the cortex and united callus was positive 4 months after implantation. But it was negative in the center of cortex after it had been implanted for over 12 months. An external callus formed from the cortex of the host. Some chondrocytes survived in non-bearing area of the articular. Neovasculature penetrated into osteoarticular.

CONCLUSION

Bone absorption may be the cause of collapse of articular surface. The results suggest that large allografts in humans are osteo-conductive rather than inductive. Incomplete repair of osteon may be related to slowed replacement of massive human allograft.

[The immune activity of polysacharide of chuanniuxi]

It reported the immune activity of polysacharide of Chuanniuxi to mouce's RES, PFC, lymphocyte transformation and NK Cell. The results show that the polysacharide can improve the activity of RES, PFC and NK Cell, but can't increace the lymphocgte stimulation index.

Extrahepatic and intrahepatic replication and expression of hepatitis C virus

In order to determine the replication sites of hepatitis C virus, the in situ hybridization and immunohistochemical technique using digoxin-labeled 531 bp plus-strand and minus-strand HCVRNA probes were employed to detect HCVRNA in the liver tissues, bone marrow mononuclear cells and peripheral blood mononuclear cells (PBMCs) from the patients with chronic hepatitis C, and in HCV transfected COS cells. The results showed that both plus-strand and minus-strand HCVRNA were detected in 80% of liver tissues (4/5). Plus-strand HCVRNA could be detected in 90% of PBMCs and bone marrow mononuclear cells (18/20), minus-strand HCVRNA in 25% of PBMCs. In HCV transfected COS cells, plus-strand HCVRNA distributed evenly in 20% cellular nuclei and cytoplasms. No minus-strand HCVRNA was detected in the bone marrow mononuclear cells and HCV transfected COS cells. The positive signal appeared in more cells when the liver tissues, PBMCs and marrow mononuclear cells were hybridized by plus-strand probes than when hybridized by minus-strand probes. Our results suggested that the hepatocytic cytoplasms and PBMC cytoplasms were the replication sites of HCV, but the marrow mononuclear cells were not the replication sites of HCV although they were infected by HCV. HCV infection might be accounted for the pathogenesis of chronic hepatitis and relapse of hepatitis C after liver transplantation.

Identification of a novel missense mutation in Wilson's disease gene

OBJECTIVE

To investigate the allelic heterogeneity of the ATP7B gene in Chinese patients with Wilson's disease (WD).

METHODS

Exons of the ATP7B gene from 141 WD patients' DNA were amplified with polymerase chain reaction (PCR) 887-890. Mutations were then screened by single strand conformation polymorphism (SSCP) analysis and further identified by sequencing.

RESULTS

The molecular structure of exon 7 of the ATP7B gene from 141 WD patients was analyzed. The same band shift in electrophoretic pattern of 4 cerebral type patients was identified with SSCP and subsequently sequenced. The results showed missense mutation at the second base of the codon as Ser 662 Cys, which is caused by a C to G transversion.

CONCLUSIONS

Mutations of the ATP7B gene were investigated for the first time in China and a novel missense mutation was identified in four cases.

In situ compositional analysis of acidocalcisomes in Trypanosoma cruzi

We measured the elemental content of different compartments in Trypanosoma cruzi epimastigotes using quick freezing, ultracryomicrotomy, and electron probe microanalysis. Vacuoles identified by high electron density contained (in units of mmol/kg dry weight +/- S.E.) large amounts of phosphorus (1390 +/- 13), magnesium (646 +/- 19), calcium (171 +/- 5), sodium (161 +/- 18), and zinc (148 +/- 6). No other compartment had appreciable calcium or zinc content. Iron (128 +/- 16 mmol/kg) was detected only in vacuoles distinct from the electron-dense vacuoles and other organelles. Incubation of cells for 70 min in culture medium in the presence of ionomycin plus nigericin led to a very significant 3- or 2-fold increase in potassium in the electron-dense vacuoles and the iron-rich vacuoles, respectively, with no significant change in the other elements investigated. This indicated the acidic nature of the vacuoles and demonstrated that the electron-dense vacuoles correspond to what were described previously as acidocalcisomes, i.e. acidic compartments rich in Ca2+. The acidocalcisomes were investigated by separation of epimastigote fractions on Percoll gradients in combination with Triton WR-1339 treatment. This detergent caused a rapid vacuolation; these vacuoles were shown by electron microscopy to be largely transparent, with a diffuse matrix. Percoll gradient fractionation demonstrated decreases in the density of various organelle markers in detergent-treated cells compared with controls. Large decreases in the density of the acidocalcisome and the mitochondrion were seen, as well as smaller decreases in the density of the other markers. Conventional electron microscopy of epimastigotes loaded with gold-labeled transferrin indicated that the endosomal system was separate from vacuoles that probably corresponded to the calcium-containing organelles detected by electron probe microanalysis. The combined results provide evidence that acidocalcisomes are organelles different from lysosomes or other organelles previously described in these parasites.

Creation and removal of embedded ribonucleotides in chromosomal DNA during mammalian Okazaki fragment processing

Mammalian RNase HI has been shown to specifically cleave the initiator RNA of Okazaki fragments at the RNA-DNA junction, leaving a single ribonucleotide attached to the 5'-end of the downstream DNA segment. This monoribonucleotide can then be removed by the mammalian 5'- to 3'-exo-/endonuclease, a RAD2 homolog-1 (RTH-1) class nuclease, also known as flap endonuclease-1 (FEN-1). Although FEN-1/RTH-1 nuclease often requires an upstream primer for efficient activity, the presence of an upstream primer is usually inhibitory or neutral for removal of this 5'-monoribonucleotide. Using model Okazaki fragment substrates, we found that DNA ligase I can seal a 5'-monoribonucleotide into DNA. When both ligase and FEN-1/RTH-1 were present simultaneously, some of the 5'-monoribonucleotides were ligated into DNA, while others were released. Thus, a 5'-monoribonucleotide, particularly one that is made resistant to FEN-1/RTH-1-directed cleavage by extension of an inhibitory upstream primer, can be ligated into the chromosome, despite the presence of FEN-1/RTH-1 nuclease. DNA ligase I was able to seal different monoribonucleotides into the DNA for all substrates tested, with an efficiency of 1-13% that of ligating DNA. These embedded monoribonucleotides can be removed by the combined action of RNase HI, cutting on the 5'-side, and FEN-1/RTH-1 nuclease, cleaving on the 3'-side. After FEN-1/RTH-1 action and extension by polymerization, DNA ligase I can join the entirely DNA strands to complete repair.

Collecting duct carcinoma of the kidney

OBJECTIVE

To describe the clinical, pathologic and immunohistochemical characteristics of collecting duct carcinoma (CDC) of the kidney.

METHODS

Five cases of CDC (3 males and 2 females, aged 41 to 67 years) were identified between January, 1990 and December, 1994. Routine histopathologic study and immunohistochemical examinations of the surgical specimens were performed.

RESULTS

Four patients underwent radical nephrectomy; 3 have been alive without evidence of recurrence for 3 months, 2 years and 2.5 years, respectively after the operation. Bone metastasis was noted 2 months after the operation in 1 case. One patient was submitted to simple nephrectomy because of extensive regional node involvement and died of lung metastasis 14 months after the surgery. Grossly, the tumors were usually grey-whitish in color and located in the renal medulla. Microscopically, the characteristic structure of tubulo-papillary pattern could be identified. Marked desmoplastic reaction was noted and atypical hyperplastic changes were found in the adjacent collecting ducts. Immunohistochemical studies revealed positive results to epithelial membrane antigen, high molecular weight cytokeratin and peanut agglutinin.

CONCLUSION

CDC of the kidney is a rare disease with a poor prognosis. Radical nephrectomy is recommended even if the tumor is small.

Mineralized nodule formation by human dental papilla cells in culture

Human dental papilla cells were enzymatically separated from deciduous tooth germs of an 8-month-old embryo legally aborted. The second passage cells were cultured up to 35 days in 3 groups. The beta-GP group was cultured in the Dulbecco MEM containing ascorbic acid and beta-glycerophosphate supplemented with 15% fetal bovine serum. The Dex group was in the same medium, in addition containing dexamethasone. The control group contained none of the 3 chemicals. Mineralized nodules were formed after 15 days in the beta-GP and Dex groups. Only in the presence of ascorbic acid and organic phosphate did they mineralize. The addition of dexamethasone caused a significant increase in the number of nodules. By electron microscopy, the nodules contained needle-shaped crystals associated with a network of collagen fibrils. Calcium and phosphorus were detected by energy-dispersive X-ray microanalysis in the nodules. Furthermore, the crystalline material exhibited a pattern consistent with hydroxyapatite and dentin when examined by X-ray diffractometry. Cells showed high levels of alkaline phosphatase activity, which was increased 2-3 times in the presence of the 3 chemicals. These results indicated that human dental papilla cells have the ability to form dentin in culture. The formation of mineralized nodules by human dental papilla in vitro provides a useful model for studying the morphogenesis and differentiation of dental papilla ectomesenchyme.

Mechanisms of ionomycin-induced endothelial cell barrier dysfunction

Myosin light chain (MLC) phosphorylation catalyzed by the Ca(2+)- calmodulin-dependent MLC kinase (MLCK) is critical to thrombin-mediated endothelial cell gap formation and barrier dysfunction. We have tested the hypothesis that the Ca2+ ionophore ionomycin stimulates MLCK-dependent endothelial cell contraction and permeability. Ionomycin significantly increased albumin clearance and decreased electrical resistance across confluent bovine pulmonary microvascular and macrovascular endothelial cell monolayers in a concentration-dependent manner that was temporally similar to that produced by thrombin. In contrast, however, ionomycin produced a significant Ca(2+)-dependent reduction in the levels of phosphorylated MLC with evidence of serine/threonine phosphatase activation. Potential MLCK-independent mechanisms of endothelial cell permeability were examined with little evidence to support a role for stimulated nitric oxide synthase or phospholipase A2 activities. Importantly, ionomycin produced 1) reductions in the activities of the barrier protective adenylate cyclase and the adenosine 3',5'-cyclic monophosphate-dependent protein kinase A, 2) dramatic dose- and time-dependent inhibition of endothelial cell tyrosine kinase activities, and 3) marked decreases in the phosphotyrosine content of the p125 focal adhesion kinase. These data indicate that ionomycin produces endothelial cell barrier dysfunction by mechanisms that are independent of MLCK activation and may involve reductions in endothelial cell tethering forces via inhibition of protein kinase A and tyrosine kinase activities, especially the p125 focal adhesion kinase.

[The expression of AT1A receptor and its modulation by benazepril in the renal tubulointerstitial lesions induced by ureteral obstruction]

OBJECTIVE

To study the expressions of angiotensin II 1A receptor (AT1A) both at the mRNA level and the protein level and their modulation by an angiotensin converting enzyme inhibitor, benazepril, in the renal tubulointerstitial injuries induced by unilateral ureteral obstruction (UUO) in rats.

METHODS

Six SD rats (UUO-T) were administered benazepril in the drinking water (50mg/L). Additional 6 rats were used as untreated controls (UUO-C). Mean arterial Prossure (MAP) was measured at the 10th day after UUO, and then all animals were sacrificed. The expressions of AT1A were examined both at the mRNA level by in situ hybridization using a subtype-specific probe and at the protein level by an immunohistochemistry methods using AT1 receptor antibody in normal rat kidneys and the obstructed rat kidneys.

RESULTS

MAP was 14.2 +/- 0. 6kPa in the UUO-T and 16.6 +/- 0.7kPa in the UUO-C (P < 0.05). Benazepril slowed the tubulointerstitial fibrosis (TIF) and reduced the expression of AT1A in the renal tubular epithelial cells, the interstitial areas, and the walls of renal arteriole in the UUO-T group.

CONCLUSION

The increased expressions of AT1A were found in the acute renal tubulointerstitial pathogenesis induced by UUO. Benazepril may retard the progression of TIF and decrease the expression of AT1A in the obstructed kidneys. We conclude that the effects of Ang II on the obstructed kidneys may be due to its binding with AT1A.

[The analysis of clinical dental crown of primary molar teeth]

For providing the anatomical data of primary molar teeth in China and using for the reference of clinical orthodontics, we measured and analysed the clinical crown of first and second primary molar teeth in 167 children of 4-6 years old finely. Each tooth was measured for 7 items with 9,228 in total. The heights of teeth crowns on buccal site were much taller than that on glossopalatal site except E. The mesial, distal and buccoglossal lenths were much longer on the enlarged part of crown than on the occlusive part. The mean values of symmetric teeth on both sites almost were of no difference. The mean values were not different in age groups (4.5 or 6 years old) either.

The role of type I collagen in the regulation of the osteoblast phenotype

Evidence from a variety of sources indicates that the extracellular matrix forms an important part of a feedback loop governing the migration, proliferation, and differentiation of the cells that produce it. In keeping with this, we showed previously that the extracellular matrix of a multipotential mesenchymal clonal cell line (ROB-C26) induced to differentiate into a more osteoblastic cell type by the addition of exogenous retinoic acid produces an extracellular matrix capable of osteoinductive activity in vivo and of stimulating alkaline phosphatase activity in vitro. Since type I collagen is the major structural component of this extracellular matrix, we sought to determine whether and to what extent this protein is responsible for the previously observed inductive/stimulatory activity. To this end, C26 cells are cultured on plastic, in the presence of retinoic acid, on a type I collagen film, or on an extracellular matrix from retinoic acid-treated C26 cells, and cell differentiation is assessed by measuring changes in the abundance of a number of osteoblast-related mRNAs. These determinations are made by RNAse protection assay after 3 or 6 days of incubation and include measurements of the RNAs for type I collagen, alkaline phosphatase, osteopontin, transforming growth factor alpha 1 and beta 2, and Vgr-1/BMP-6. In addition, C26 cells are incubated in the presence of retinoic acid and several established inhibitors of the synthesis or assembly of extracellular matrix components and the effects on induced alkaline phosphatase activity determined. Our data show that while the collagen substrate mimics some of the effects of retinoic acid and the extracellular matrix, it cannot reproduce all of them. Specifically, while the latter two culture conditions increase the abundance of all six mRNAs, type I collagen film increases the levels of only three of the six (collagen I, alkaline phosphatase, and osteopontin). Moreover, while type I collagen film produces an increase in alkaline phosphatase message, it falls to produce a similar change in alkaline phosphatase activity, an effect seen with both retinoic acid and extracellular matrix. However, interruption of collagen I synthesis by cis-4-hydroxy-L-proline blocks the increase in alkaline phosphatase activity associated with retinoic acid treatment. Thus, it appears likely that type I collagen is a necessary but, by itself, insufficient factor to elicit the comprehensive expression of the osteoblastic phenotype in immature mesenchymal cells.

[A simplified theory of protrusive balanced occlusion in complete denture and its application]

Based the study of the theory of protrusive balanced occlusion in complete denture construction and clinical experience the author established a new simplified theory named "the three principle factors and three laws for protrusive balanced occlusion in complete denture" to guide us to arrange teeth for balanced occlusion in complete denture construction. Based this theory the phenomena of protrusive occlusal disharmony appeared in the process of teeth arrangement and denture insertion can be corrected easily.

[Constituents of essential oil of imported myrrh and gum opoponax]

The constitutents of essential oil in two kinds of Myrrha were analyzed by GC-MS. Fifteen compounds in Myrrh and thirty-three compounds in Gum opoponax were identified with their percent contents given. The main constituent of Myrrh is furanoeudesma-1,3-diene, and the main constituent of Gum opoponax is beta-trans-ocimene.

[Effects of aspirin and nifedipine alone or in combination on mesenteric microcirculation of rats]

AIM

To study the effects of the combination of aspirin (Asp) and nifedipine (Nif) on mesenteric microcirculation of rats.

METHODS

Acute microcirculation disturbance (AMD) was produced by high molecular weight dextran (M(r) 480,000, 360 mg.kg-1 i.v.). Arteriole and venule blood flow velocity and diameter (ABFV, VBFV, AD, VD) and blood flow state (BFS) were observed by intravital microcirculation method.

RESULTS

Asp 2.5, 5 mg.kg-1, Nif 0.05, 0.1 mg.kg-1, Asp + Nif (1 + 0.025), (2.5 + 0.05) mg.kg-1, i.v. had the significant increase of 11.1%, 31.3%, 18.5%, 19.3%, 30.5%, 39.8% of ABFV and 12.5%, 25.7%, 12.6%, 15.2%, 29.6%, 36.1% of VBFV respectively, the marked improvement of BFS, and the distinctive increase of 4.3%, 17.9%, 35.9%, 39.7%, 15.2%, 42.8% of AD and 2.2%, 4.2%, 26.2%, 27.4%, 3.4%, 28.9% of VD separately, and got a raise in the number of capillaries. Asp + Nif (1 + 0.025), 2.5 + 0.05) mg.kg-1 i.v. could reverse AMD.

CONCLUSION

Asp was superior to Nif in the increase of BFV, but Nif was superior to Asp in expansion of blood vessel. Asp in combination with Nif produced marked synergistic action and protection againist AMD.

Thickness measurement of hydrated and dehydrated cryosections by EELS

Electron energy-loss spectroscopy (EELS) provides a useful method for determining the thickness of frozen-hydrated and dehydrated cryosections in terms of the inelastic mean free path. Cryosection thickness is an important parameter because plural inelastic scattering limits the sensitivity of elemental microanalysis based on core-loss EELS, and because overlapping structures can affect interpretation of microanalytical data as well as the quality of electron images. The purpose of this work was to establish the minimum practical thickness for cutting cryosections and to explain the measured values for hydrated and dehydrated specimens. Hydrated sections were typically found to be between 1.5-2.5 times thicker than expected from the nominal microtome setting; this difference can be largely explained by compression during cutting. Comparison of micrographs from hydrated and dehydrated cryosections of rapidly-frozen, vitrified liver revealed a lateral shrinkage of approximately 20% on drying. The measured compression and shrinkage factors are consistent with dark-field scanning transmission electron microscopy (STEM) mass measurements on freeze-dried sections. Freeze-dried cryosections, cut to a nominal thickness of 90 nm and supported on thin Formvar/carbon films, had a relative thickness t/lambda i in the range of 0.5 for cytoplasm to 0.9 for mitochondria when analyzed at 100 keV beam energy. Mass loss of approximately 30% occurring at high electron dose enabled useful core-loss spectra to be recorded even from high-mass compartments such as mitochondria without excessive plural scattering.

[Effects of aspirin and nifedipine alone or in combination on hemodynamics in anesthetized dogs]

AIM

To study the effects of the combination of aspirin (Asp) and nifedipine (Nif) on hemodynamics in 8 anesthetized dogs.

METHODS

Tension time index (TTI), left ventricular work index (LVWI), mean arterial pressure (MAP), and total peripheral vascular resistance (TPVR), femoral artery blood flow (FBF), ventricular systolic pressure (LVSP), maximum of its first derivative (dp/dt(max)), left ventricular end diastolic pressure (LVEDP) and heart rate (HR) were recorded on polygraph and electromagnetic flowmeter.

RESULTS

Asp 5, 10 mg.kg-1, i.v. exerted a significant effect on the hemodynamic indices, wheras Nif 15 micrograms.kg-1, i.v. decreased TTI, LVWI, MAP, and TRVR, increased FBF distinctively, and slightly affected LVSP, dp/dt(max), LVEDP, and HR. The effects of Asp in combination with Nif on hemodynamics were similar to those of Nif alone.

CONCLUSION

The improvement of cardiovascular function caused by Nif was not affected by the presence of Asp.

[Uterine papillary serous carcinoma and papillary endometrial carcinoma: analysis of clinical biological behaviors of 56 cases]

OBJECTIVE

To characterize the clinical biological behavior and the pathological morphology of uterine papillary serous carcinoma and papillary endometrial carcinoma.

METHODS

This is a retrospective analysis of 56 patients with papillary endometrial cancer treated at Cancer Hospital. Chinese Academy of Medical Sciences from January, 1981 to December, 1993. Of the 56 cases, 15 were uterine papillary serous carcinomas (UPSC), 41 papillary endometrial carcinomas (PEC). One hundred and sixty patients with endometrial adenocarcinoma (AC) were submitted as control group.

RESULTS

26.7% of UPSC, 14.6% of PEC and 5.6% of AC patients had stage III or IV by clinical examination (P < 0.05), whereas 53.3% of UPSC, 20.8% of PEC and 12.1% of AC patients has extrauterine disease at surgery (P < 0.01). Deep myometrial invasion occurred in 75.0% of UPSC, 41.7% of PEC, and 32.3% of AC patients (P < 0.01). An increasing gradient of 5 year survival rate (life table method) was observed from UPSC (45.7%) to PEC (61.9%) to AC (90.3%) in their early stage (stage I-II) (P < 0.01). Upper abdominal spread was a common finding in UPSC which had a high rate of persistent disease (46.2%). The pelvis was the predominant involving site in PEC with a high frequency of recurrence and metastasis (31.0%).

CONCLUSIONS

The presence of papillary features in endometrial carcinoma is an important prognostic indicator. The prognosis of PEC is better than UPSC, but worse than AC.

[Mammaplasty immediately after mastectomy for breast cancer]

From March 1990 to March 1994, 7 cases of one stage breast reconstruction with silicone prosthesis after mastectomy for breast cancer were performed in our hospital. All the operations were successful and no operative complication observed. They were followed up for three months to four years. The contour was good, symmetrical, soft to touch and the patients did not complain uncomfortable sensation. The authors propose that immediate reconstruction of the breast be recommended. In this paper, the indications, methods, selection of opportune time for operation and precautions are discussed.

[Surgical treatment of avascular necrosis of the femoral head]

71 patients (83 hips) with avascular necrosis of the femoral head were followed up. The patients had bilateral necrosis (12), and unilateral (59). Their ages ranged from 19 to 71 years. Ficat classification showed stage I for 1 hip, stage II 19 hips, stage III 35 hips, and stage IV hips. According to the severity, the range of motion, the age, and the X-ray appearances, 6 kinds of procedures were used including decompression with bone grafting (32 hips), surface arthroplasty with cartilage (4), surface arthroplasty with fascia (4), replacement of femoral head (7), THA (20), and obturator neuroetomy (16). The follow-up period ranged from 2 years and 3 months to 10 years and 5 months. Postoperative improvement included pain (39.7%), range of motion (21.7%), and walking (33.7%). Among the procedures, decompression with bone grafting showed best results. Treatment revealed better results in stage I, II than in stage III, IV. We emphysize the early diagnosis and management, and choice of procedure should base on the clinical classification.

[Effects of lead on neurobehavior and neurochemistry in rats]

Effects of exposure to lead on neurobehavioral function, content of monoamine neurotransmitter in hippocampus, and brain level of lipid peroxide were studied in 45 SD rats. Results showed learning and memory abilities of the rats were affected in exposure to lead of 1333.3 mg/kg (with their blood lead level of 6.23 mumol/L), their motor activities changed and emotional status became unsteady with 266.7 mg/kg of lead (with blood lead of 4.20 mumol/L) and 1333.3 mg/kg of lead, respectively, and levels of dopamine neurotransmitter and its metabolites declined and those of lipid peroxide increased with increasing exposure to lead. It is postulated changes in levels of neurotransmitter, such as monoamine and lipid peroxide, could explain the mechanism for damage in neurobehavioral function caused by lead exposure.

cDNA cloning, sequencing and in situ localization of a transcript specific to both sublingual demilune cells and parotid intercalated duct cells in mouse salivary glands

A cDNA clone derived from mouse sublingual gland was isolated from lambda-phage cDNA library. Northern blot hybridization indicated that the transcript from which it was derived was approx. 700 nucleotides in length. This mRNA encoded a protein of about 20 kDa, as determined by hybrid selection and cell-free translation. Conceptual translation of the cDNA clones showed that p20 is 170 amino acids in length. The putative protein is hydrophobic in nature, is neither a mucin-like protein nor does its amino acid sequence or composition resemble the other known mouse proteins. However, the amino acid sequence of p20 suggests that it may be from a gene or gene family homologous to rat common salivary protein 1. The p20 mRNA also appears to share a non-random degree of sequence homology with the cysteine-rich domains of bovine and porcine submandibular mucins. The p20 mRNA is abundant in the mouse sublingual gland, and its expression is approx. nine times greater than in the parotid gland. In situ hybridizations localized the p20 mRNA exclusively in the demilune cells of the sublingual gland and in the intercalated duct cells of the parotid gland. It is detectable in the neonatal and adult submandibular gland at very low levels, but is absent from liver, heart, brain, thymus, spleen, lens and lacrimal glands.

[Correction of severe epicanthus using the square-flap method]

The square-flap method has been adopted gradually in plastic surgery because of lengthening effectively the distance between two points on the skin surface. Good results have been obtained in the treatment of severe epicanthus in 14 cases of 26 eyes by using modified square flap since 1990. This paper describes the operation design, advantages and key points of the surgery.

Levels of expression of the genes for glutathione reductase, glutathione peroxidase, catalase and CuZn-superoxide dismutase in rat lens and liver

Oxidative mechanisms are thought to play a major role in several biological phenomena, including cataract formation. In the following studies we determined the relative levels of expression of the genes for the mRNAs for glutathione peroxidase (GPx), glutathione reductase (GR), CuZn-superoxide dismutase (CuZn-SOD) and catalase, in both the rat lens and liver. Northern blot hybridization methods were used to determine the mRNA size. The RNase protection method was used to determine levels of expression for these mRNAs plus levels of expression for alpha A-crystallin and gamma-crystallin mRNAs in the lens, and gamma-actin mRNAs in both the lens and the liver; using [32P]-labeled specific cRNA probes transcribed from the various cDNA clones for the mRNAs being studied. The data was normalized relative to the level of expression of alpha A-crystallin and gamma-actin mRNAs in the lens, and to gamma-actin mRNA in the liver. We find the levels of the mRNAs in the lens fall in the following descending order: GPx > GR > CuZn-SOD > catalase, in the same order as has been reported for the activities of the enzymes in the lens. In the liver, levels of these mRNAs were as follows: GPx > CuZn-SOD > GR > catalase. In the liver, CuZn-SOD mRNA was expressed at about four times the level found in the lens, GPx at three times, catalase at three times and GR at about the same level.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal expression of aldose reductase mRNA in fiber cells of cataractous rat lens. Analysis by in situ hybridization

Aldose reductase (AR), an enzyme of the polyol pathway, has been implicated in the pathogenesis of diabetic and galactosemic cataracts. AR mRNA is a specific transcript of the lens epithelial cells. However, in addition to its presence at high levels in the epithelial cells at the equator, it is also found at significant concentrations in fiber cells at the lens bow. In this study we extended our previous work, and examined the distribution of AR mRNA by in situ hybridization in lens of rats maintained on a 50% galactose diet for up to 20 days, then reversed to a normal diet for an additional 20 days. It was found that within 8 days on galactose the posterior AR mRNA dissipated, with no clear increase in this transcript in the lens epithelial cells. By 16 to 17 days on galactose, the surviving fiber cells in the equatorial region appeared to express AR mRNA; these cells in the normal lens contain insignificant amounts of AR mRNA, as we have previously demonstrated. AR mRNA in the fiber cells of the cataractous lens appears to be of the same base length as that found in the control, indicating that the AR mRNA in these cells may not represent a degraded transcript. Upon reversal of the cataracts, the posterior AR mRNA re-accumulates, and the fiber cells at the equator appear to have lost the AR mRNA that accumulated during the period of exposure to galactose. The data demonstrate that during formation of galactose-cataract, surviving cortical fiber cells express significant levels of AR mRNA, while following withdrawal from galactose these fiber cells lose that activity.

[The trend of mortality of lung cancer and its association with air pollution]

A death retrospective survey of all causes from 1985 to 1989 was carried out in thirteen districts of Shandong Province in 1990. The total population investigated was 8.10 million that accounted for nearly ten percent of the whole population of Shandong. The death rate of lung cancer (adjusted by Chinese population in 1964) was 12.0 per 100,000 population. As compared with that in 1970-1974, it increased by 96.7%, of which 102.5% for male and 85.7% for female. In each district the mortality of lung cancer also went up. In Qingtao, Jinan, and Zibo with high-mortality in 1970-1974, the rates of lung cancer death increased by 213%, 291%, and 260%, respectively. At the same time, in Zhaozhuang, Jining, Hezie with low-mortality in 1970-1974, the mortality rates of lung cancer increased by 303%, 284% and 285%, respectively. The results of correlational analysis showed that the increasing rate of lung cancer was related to the air pollution.

Water distributions of hydrated biological specimens by valence electron energy loss spectroscopy

A technique has been developed for measuring the water distribution in thin frozen hydrated biological specimens by means of electron energy loss spectroscopy (EELS). The method depends on the quantification of subtle changes in the valence electron excitation spectrum as a function of composition. It involves determining the single-scattering intensities, calculating oscillator strengths and applying a multiple-least-squares fitting procedure to reference spectra for water and the organic constituents. The direct EELS approach has an important advantage over other indirect methods that are based on X-ray generation or elastic scattering measurements since these are applied to freeze-dried specimens where differential shrinkage between compartments may produce errors. Precision and accuracy of the EELS method have been tested on cryosectioned solution of bovine serum albumin; data have also been obtained from cryosections of rapidly frozen erythrocytes. Results suggest that a precision of better than +/- 5% (s.d.) is attainable from a single measurement and the accuracy may be as high as +/- 2% if repeated measurements are made. The lateral spatial resolution of the water determinations is limited by radiation damage to approximately 100 nm which is of the same order as the specimen thickness.

Profile of messenger RNA decay in the Emory mouse lens in cataractogenesis and in aging

The Emory mouse is presumed to be a model for studies on human senile cataracts. The cataract develops in 5-8 months after birth, and it does not appear to have an osmotic component. To date, no specific metabolic lesion has been uncovered as a probable cause to this cataract. Several studies have shown that the Emory mouse undergoes accelerated aging changes, possibly leading to development of senile-type cataracts. In this study we quantitated changes that might occur in the population of various mRNAs for proteins presumed to be essential for lens transparency, and for proteins that may contribute to development of cataracts. By Northern blot hybridization analysis we quantitated the mRNAs for: alpha A-crystallin, beta B1-crystallin, gamma-crystallin, the main lens intrinsic membrane protein, MP26, and aldose reductase; all in lenses of Emory mouse early cataract strain (EMEC), and of an age-matched cataract resistant strain (CR). These measurements were done in increments of 1 month over a 6-month period, then at both 9 and 12 months. The results show that all of these mRNAs decrease with age and with development of cataracts; although in some cases the initial concentrations at 1 month appear to be lower in the EMEC than in the CR strain. The most dramatic change occurred with the MP26 mRNA. In the CR strain, MP26 mRNA maintained its high concentration for a period of about 6 months before it began its decline to the 12 month level (about 25% of the 1 month level).(ABSTRACT TRUNCATED AT 250 WORDS)

Transient elevation of aldose reductase mRNA in lens of rats developing galactose cataracts

Aldose reductase (AR), a major enzyme in the polyol pathway, is thought to be responsible for accumulation of polyols in lenses exposed to high doses of galactose or glucose, and it may be linked to some of the complications found in diabetes. In this report we examined the level of expression of AR mRNA in lens epithelia undergoing development of galactose cataracts in vivo. The AR mRNA was quantitated by Northern blot hybridization with a [35S]-RNA transcript from a previously described AR cDNA clone. This was done on normal lens epithelia and on epithelia from lens of rats fed a diet of Purina Chow containing 50% galactose for periods of from 6 hr to 20 days. We found AR mRNA to elevate to about 5-fold the control levels by 12-24 hr on galactose, then decrease to the control levels by day 4. The increase in AR mRNA appears to be transitory. The high abundance in AR mRNA by 24 hr on galactose was confirmed by in situ hybridization. At later periods, from 8 to 20 days on galactose, a slow increase in AR mRNA took effect, as we have previously reported. Changes in the levels of galactose and dulcitol between 0 and 96 hr were also quantitated by gas chromatography, showing that there was a significant increase in both galactose and dulcitol occurring throughout the experimental period.(ABSTRACT TRUNCATED AT 250 WORDS)