bluuebunny/crossref_metadata_2025 huggingface dataset:
Different actin affinities of human cardiac essential myosin light chain isoforms
Authors: Morano I , Haase H
Published: July 2002

The N terminus of myosin light chain 1 (MLC‐1) of skeletal muscle bind to the C terminus of actin. We investigated whether the N termini of human cardiac MLC‐1 isoforms likewise bind to actin. Furthermore, we investigated whether the N‐terminal sequence 5–15 (P5–14) of MLC‐1 of human atrium (ALC‐1) and ventricle (VLC‐1) bind with different affinities to actin. Affinity beads were produced by covalently coupling a synthetic peptide corresponding to the N‐terminal sequence 4–14 of human VLC‐1 to aminohexylagarose in order to bind G‐actin. We found, that G‐actin specifically binds to the affinity beads. Furthermore, preincubation of G‐actin with P5‐14 of both ALC‐1 and VLC‐1 decreased the amount of G‐actin recovered from the affinity beads in a concentration‐dependent manner. The half‐maximal effective concentrations, however were significantly (p<0.01) different being 0.32±0.02 μM and 0.71±0.02 μM for the VLC‐1 and ALC‐1 peptide, respectively. The appropriate scrambled peptides were without effect up to 3 μM. These results demonstrate the specific interaction between the N‐terminal domains of human cardiac MLC‐1 isoforms and actin and reveal different actin affinities of MLC‐1 isoforms. Weak binding of ALC‐1 to actin could explain the higher cycling kinetics of cross‐bridges with ALC‐1 compared to those with VLC‐1.
Regulatory effects of aggregated LDL on apoptosis during foam cell formation of human peripheral blood monocytes
Authors: Kubo Nobuhiko , Kikuchi Jiro , Furukawa Yusuke , Sakai Toshihiko , Ohta Hatsunori , Iwase Satsuki , Yamada Hisashi , Sakurabayashi Ikunosuke
Published: July 2002

In order to investigate the mechanisms how modified lipoproteins enhance foam cell formation, we cultured peripheral blood monocytes with various stimulants and examined the effects of aggregated low‐density lipoprotein (agLDL) on cell viability and lipid metabolism. AgLDL could completely inhibit phorbol ester‐induced apoptosis, which was accompanied by intracellular cholesterol accumulation. Suppression of apoptosis‐promoting proteases, ICE and CPP32, was observed in agLDL‐treated cells. This indicates that agLDL accelerates foam cell formation through inhibition of apoptosis and enhancement of lipid accumulation in activated monocytes. By contrast, apoptosis was enhanced when monocytes were cultured with agLDL and M‐CSF. Intracellular cholesterol accumulation was not significant in M‐CSF treated cells. This suggests that M‐CSF may act anti‐atherogenic through apoptotic elimination of lipid‐baring macrophages and enhanced lipid turnover. Our observation supports the novel hypothesis that regulation of apoptosis may play an important role in the development of atherosclerosis.
An estrogen inducible 104 kDa chaperone glycoprotein binds ferric iron containing proteins: a possible role in intracellular iron trafficking
Authors: Poola Indra
Published: July 2002

We have previously described an estrogen inducible, intracellular, homodimeric membrane glycoprotein (subunit M
r 104 kDa) which is structurally related to ‘chaperone’ proteins (Poola, I. and Kiang J.G., J. Biol. Chem. 269 (1994) 21762–21769). In this report we describe a novel finding that the 104 kDa chaperone protein exhibits affinity for iron containing proteins such as transferrins from several species, human lactoferrin and microbial ferric binding protein (FBP). A single ferric ion in the above proteins appears to be sufficient for binding. It also binds to immobilized ferritin. However, it does not exhibit any affinity for apotransferrins, apolactoferrin, apoferritin and apoFBP. This is the first report of a chaperone protein that exhibits affinity for iron containing proteins.
Promoters of epithelialization induce expression of vascular endothelial growth factor in human gastric epithelial cells in primary culture
Authors: Takahashi Morio , Ogura Keiji , Maeda Shin , Mori Kiyoshi , Mafune Ken-ichi , Mikami Yasuyo , Terano Akira , Omata Masao
Published: July 2002

Both epithelialization and angiogenesis are indispensable processes in gastric ulcer healing. Coordination between these processes has not been well studied. In the present study, we have established a new primary culture system of human gastric epithelial cells and investigated the effect of epithelialization stimulants on a specific angiogenic factor, vascular endothelial growth characterized as epithelial cells. Both epithelialization stimulants, hepatocyte growth factor (HGF) and epidermal growth factor (EGF), significantly stimulated vascular EGF expression in gastric epithelial cells. HGF and EGF receptors were expressed by the cells, suggesting that regulation may be mediated through specific receptors.
Selective activation of JNK/SAPK by interleukin‐1 in rabbit liver is mediated by MKK7
Authors: Finch Andrew , Holland Pamela , Cooper Jonathan , Saklatvala Jeremy , Kracht Michael
Published: July 2002

Activation of jun N‐terminal kinase (JNK)/stress‐activated protein kinase (SAPK) by interleukin‐1 (IL‐1) has been reported in many cells and in rabbit liver. Here we report selective activation of JNK/SAPK, without activation of p38 or p42 mitogen‐activated protein kinases (MAPKs), by IL‐1 in rabbit liver. We identified an IL‐1 regulated JNK/SAPK activator present in rabbit liver using S Sepharose chromatography. It was purified and immunoprecipitated by two antisera to MAP kinase kinase 7 (MKK7). It was not recognised by an antibody to MKK4. We conclude that MKK7 is the activator of JNK/SAPK activated by IL‐1 in liver and that JNK/SAPK is the only MAPK activated by IL‐1 in liver.
Regulation of protein kinase C in the muscular layer of human placental stem villi vessels
Authors: Tertrin-Clary C , Fournier T , Ferré F
Published: July 2002

Protein kinase C (PKC) activity in the muscular layer of stem villi vessels from the human term placenta was studied. Resting state PKC activity was distributed evenly between the cytosol and the particulate fractions. Upon stimulation by three different activators, phorbol 12‐myristate 13‐acetate, fluoride and endothelin‐1, a translocation of PKC activity from the cytosolic to the particulate fraction was observed. The expression and distribution of PKC isoforms were then examined by Western blot analysis using specific antibodies to PKC isoforms. At least four PKC isoforms, PKCα, PKCβ1, PKCβ2, PKCζ, and trace amounts of PKCϵ were detected in both fractions. Their relative responses to the different agonists were examined by quantifying their subcellular redistribution. No significant differential activation of the four mainly expressed PKC isoforms were observed in response to stimulation with any of the stimuli. Moreover, our results show that endothelin‐1 induced translocation/activation of PKC in this vascular smooth muscle.
Evidence for intrinsic DNA bends within the human cdc2 promoter
Authors: Nair T.Murlidharan
Published: July 2002

Cyclin‐dependent protein kinases (Cdks) are key regulatory proteins of the eukaryotic cell cycle. The product of the cdc2 gene, p34cdc2 (cdk1), is the catalytic subunit of a serine/threonine protein kinase that is expressed in S phase and functions in the G2 to M phase transition. Previous studies indicate that the human cdc2 gene expression is dependent on cell growth, and is transcriptionally regulated in a complex manner involving multiple transcription factors binding to specific sites in the promoter. One possible mechanism by which these transcription factors regulate transcription is that by binding to their cognate sites they induce bends in the DNA helix, thereby allowing their interaction with the basal transcription machinery through protein‐protein contacts. Such protein‐induced DNA bending is also influenced by intrinsic bends in the regulatory region. Using both theoretical and experimental approaches, the study reports that the human cdc2 promoter has an intrinsic DNA bend with a broad locus of curvature.
Analogs of farnesylcysteine induce apoptosis in HL‐60 cells
Authors: Pérez-Sala Dolores , Gilbert Bryant A , Rando Robert R , Cañada Francisco J
Published: July 2002

S‐Farnesyl‐thioacetic acid (FTA), a competitive inhibitor of isoprenylated protein methyltransferase, potently suppressed the growth of HL‐60 cells and induced apoptosis, as evidenced by the development of increased annexin‐V binding, decreased binding of DNA dyes and internucleosomal DNA degradation. FTA did not impair the membrane association of ras proteins, conversely, it brought about a decrease in the proportion of ras present in the cytosolic fraction. Farnesylated molecules which are weak inhibitors of the methyltransferase also induced DNA laddering and reduced the proportion of cytosolic ras. These findings suggest that neither inhibition of isoprenylated protein methylation nor impairment of ras membrane association are essential for apoptosis induced by farnesylcysteine analogs.
Identification of two forms of the γ subunit of G protein, γ10 and γ11, in bovine lung and their tissue distribution in the rat
Authors: Morishita Rika , Ueda Hiroshi , Kato Kanefusa , Asano Tomiko
Published: July 2002

Two forms of the γ subunit of G protein were purified from bovine lung, and were identified as γ10 and γ11 by analyses of partial amino acid sequences and reactivity with specific antibodies. The N‐terminal amino acid residue of γ11 was an unmodified Pro2, and the purified γ11 was freed from β even under non‐denaturing conditions. Western blots with specific antibodies against γ10 and γ11 showed that both γ subunits are present in a variety of tissues in the rat, with a particular abundance of γ11 in the platelets.
Intrahelical side chain interactions in α‐helices: poor correlation between energetics and frequency
Authors: Fernández-Recio J , Sancho J
Published: July 2002

Polypeptide sequences in proteins may increase their tendency to adopt helical conformations in several ways. One is the recruiting of amino acid residues with high helical propensity. Another is the appropriate distribution of residues along the helix to establish stabilising side chain interactions. The first strategy is known to be followed by natural proteins because amino acids with high helical propensity are more frequent in α‐helices. If proteins also followed the second strategy, stabilising amino acid pairs should be more frequent than others. To test this possibility we compared empirical energies of side chain interactions in α‐helices with statistical energies calculated from a data base of proteins with low homology. We find some correlation between the stability afforded by the pairs and their relative abundance in α‐helices but the realisation of energetic preferences into statistical preferences is very low. This indicates that natural α‐helices do not regularly use intrahelical side chain interactions to increase their stability.
Phospholipase cleavage of glycosylphosphatidylinositol reconstituted in liposomal membranes
Authors: Villar Ana Victoria , Goñi Félix M , Alonso Alicia , Jones David R , León Yolanda , Varela-Nieto Isabel
Published: July 2002

Glycosylphosphatidylinositol (GPI) purified from rat liver lipids was incorporated into lipid bilayers of defined compositions, in the form of large unilamellar vesicles. The GPI concentration in the bilayers was kept constant at 25 mole%, whereas the remaining lipids being phosphatidylcholine, phosphastidylethanolamine, sphingomyelin and/or cholesterol were varied. The resulting liposomes consisted of spherical vesicles, approximately 100 nm in diameter, that could keep their aqueous contents separated from the extravesicular medium. When these liposomes were treated with either Bacillus cereus phosphatidylinositol‐phospholipase C, Trypanosoma brucei GPI‐phospholipase C, or bovine serum GPI‐phospholipase D, GPI was hydrolyzed at different rates, depending on the enzyme and the bilayer lipid composition. These observations open the way to biophysical and biochemical studies of enzymic GPI cleavage under defined conditions. Extensive GPI hydrolysis was observed in certain cases that could allow the use of these systems for the preparation of inositol phosphoglycans, proposed second messengers of a wide variety of hormones, cytokines and growth factors.
Concomitant activation of Gi and Gq protein‐coupled receptors does not require an increase in cytosolic calcium for platelet aggregation
Authors: Pulcinelli Fabio M , Pesciotti Marzia , Pignatelli Pasquale , Riondino Silvia , Gazzaniga Pier Paolo
Published: July 2002

U46619 is a potent platelet agonist, its binding to the thromboxane A2 receptor resulting in Gq‐binding protein‐mediated responses; nevertheless, it is unable to cause platelet aggregation, unless released ADP is present. In this study we demonstrate that Gi activation is the step U46619 lacks to cause platelet aggregation; in fact, when platelets were treated with an ADP scavenger system, the response to U46619 was restored by the addition of epinephrine, which activates platelets via a Gi protein. The concomitant activation of Gi and Gq proteins does not require increased cytosolic calcium to cause aggregation, as assessed by the fact that platelets treated with the intracellular calcium chelator BAPTA were able to respond to U46619 provided ADP or epinephrine was present. Moreover, as the calcium ionophore ionomycin, at low concentrations, potentiated the response to U46619 but not to epinephrine, we may conclude that calcium influx preferentially activates a Gi downstream signalling pathway.
Transformed but not normal hepatocytes express UCP2
Authors: Carretero M.Victoria , Torres Luis , Latasa M.Ujue , Garcı́a-Trevijano Elena R , Prieto Jesús , Mato José M , Avila Matı́as A
Published: July 2002

Uncoupling protein 2 (UCP2) expression in liver is restricted to non‐parenchymal cells. By means of differential display screening between normal rat liver and H4IIE hepatoma cells we have isolated a cDNA clone encompassing part of UCP2 cDNA. Northern blot analysis revealed that UCP2 is expressed in some hepatocarcinoma cell lines, while it is absent in adult hepatocytes. UCP2 mRNA in H4IIE cells was downregulated when cells were cultured for 36 h in 0.1% serum and its expression was restored upon addition of 10% serum or phorbol esters. Hypomethylation of UCP2 was observed in transformed UCP2 expressing cells. Our results indicate that UCP2 is expressed in some hepatocarcinoma cell lines and that serum components may participate in maintaining elevated UCP2 levels.
Random coil conformation of a Gly/Ala‐rich insert in IκBα excludes structural stabilization as the mechanism for protection against proteasomal degradation
Authors: Leonchiks Ainars , Liepinsh Edvards , Barishev Mikhail , Sharipo Anatoly , Masucci Maria G , Otting Gottfried
Published: July 2002

Peptide segments of multiple glycine and alanine residues prevent the proteolytic degradation of ubiquitinated proteins by the proteasome. The structure of a Gly/Ala‐rich insert in IκBα was probed by nuclear magnetic resonance (NMR) spectroscopy, comparing IκBα samples with and without Gly/Ala‐rich insert. Narrow 1H‐NMR resonances at chemical shifts indicative of random coil conformations were observed in the difference spectrum. circular dichroism (CD) measurements further confirm that the mechanism of protection against proteolytic degradation is not based on structural transition or stabilization caused by the Gly/Ala‐rich segment. In addition, most of the N‐ and C‐terminal residues outside the ankyrin repeats in wild‐type IκBα were found to be flexibly disordered.
The CGRP receptor can couple via pertussis toxin sensitive and insensitive G proteins
Authors: Main Martin J , Brown Jason , Brown Susan , Fraser Neil J , Foord Steven M
Published: July 2002

Swiss 3T3 cell lines were constructed co‐expressing receptor activity modifying protein (RAMP) 1 with the calcitonin receptor‐like receptor (CRLR), and showed 125I‐calcitonin‐gene‐related peptide (CGRP) 1 binding indicative of a type I CGRP receptor. Application of CGRP1 led to an increase in cAMP, which in 2/5 cell lines was augmented following pertussis toxin (PTX) pre‐treatment. In Xenopus oocytes, expression of RAMP1, which potentiates an endogenous CGRP receptor, led to constitutive activation of co‐expressed GIRK potassium channels. This potassium current was increased following CGRP application or co‐expression of CRLR, but decreased by PTX or co‐expression of transducin. We conclude that the CGRP receptor can signal to both PTX sensitive and insensitive G proteins.
In vivo formation of Cu,Zn superoxide dismutase disulfide bond in Escherichia coli
Authors: Battistoni Andrea , Mazzetti Anna Paola , Rotilio Giuseppe
Published: July 2002

We have found that the in vivo folding of periplasmic Escherichia coli Cu,Zn superoxide dismutase is assisted by DsbA, which catalyzes the efficient formation of its single disulfide bond, whose integrity is essential to ensure full catalytic activity to the enzyme. In line with these findings, we also report that the production of recombinant Xenopus laevis Cu,Zn superoxide dismutase is enhanced when the enzyme is exported in the periplasmic space or is expressed in thioredoxin reductase mutant strains. Our data show that inefficient disulfide bond oxidation in the bacterial cytoplasm inhibits Cu,Zn superoxide dismutase folding in this cellular compartment.
Arachidonic acid induces the activation of the stress‐activated protein kinase, membrane ruffling and H2O2 production via a small GTPase Rac1
Authors: Shin Eun Ah , Kim Kyung Hee , Han Song Iy , Ha Kwon Soo , Kim Jae-Hong , Kang Kwang Il , Kim Han Do , Kang Ho Sung
Published: July 2002

Arachidonic acid (AA) is generated via Rac‐mediated phospholipase A2 (PLA2) activation in response to growth factors and cytokines and is implicated in cell growth and gene expression. In this study, we show that AA activates the stress‐activated protein kinase/c‐Jun N‐terminal kinase (SAPK/JNK) in a time‐ and dose‐dependent manner. Indomethacin and nordihydroguaiaretic acid, potent inhibitors of cyclooxygenase and lipoxygenase, respectively, did not exert inhibitory effects on AA‐induced SAPK/JNK activation, thereby indicating that AA itself could activate SAPK/JNK. As Rac mediates SAPK/JNK activation in response to a variety of stressful stimuli, we examined whether the activation of SAPK/JNK by AA is mediated by Rac1. We observed that AA‐induced SAPK/JNK activation was significantly inhibited in Rat2‐Rac1N17 dominant‐negative mutant cells. Furthermore, treatment of AA induced membrane ruffling and production of hydrogen peroxide, which could be prevented by Rac1N17. These results suggest that AA acts as an upstream signal molecule of Rac, whose activation leads to SAPK/JNK activation, membrane ruffling and hydrogen peroxide production.
Mutational analysis of subunit iβ2 (MECL‐1) demonstrates conservation of cleavage specificity between yeast and mammalian proteasomes
Authors: Salzmann Ulrike , Kral Sylvie , Braun Beate , Standera Sybille , Schmidt Marion , Kloetzel Peter-M , Sijts Alice
Published: July 2002

Proteasomes are the major protein‐degrading complexes in the cytosol and regulate many cellular processes. To examine the functional importance of the MC14/MECL‐1 proteasome active site subunits, cell lines expressing a catalytically inactive form of MECL‐1 were established. Whereas mutant MECL‐1 was readily incorporated into cytosolic proteasomes, replacing the constitutive MC14 subunit, removal of the prosequence was incomplete indicating that its processing required autocatalytic cleavage. Functional analyses showed that the absence of the MC14/MECL‐1 active sites abrogated proteasomal trypsin‐like activity, but did not affect other catalytic activities. Our data demonstrate a conservation of cleavage specificity between mammalian and yeast proteasomes.
Identification of a new gene encoding pericentromeric dodeca‐satellite binding protein in Drosophila melanogaster
Authors: De Felice B , Pontecorvo G , Carfagna M
Published: July 2002

Dodeca‐satellite (CCCGTACTCGGT)n is a type of tandemly repeated DNA sequence located in the pericentromeric region of the third chromosome of Drosophila melanogaster and that cross‐hybridizes with DNA from other species such as Arabidopsis, mouse and human. This evolutionary conservation suggests that dodeca‐satellite might play an important role in the centromeric function. Therefore, the aim of our research was the isolament of genes encoding proteins that might help stabilize these DNA structures, in vivo. To identify D. melanogaster sequence DNAs encoding dodeca‐satellite binding proteins, we used the in vivo yeast assay, known as ‘one‐hybrid system’. Here, we identified a novel gene sequence that encoded pericentromeric dodeca‐satellite binding protein and described its sequence characteristics.
N‐terminally truncated Vav induces the formation of depolymerization‐resistant actin filaments in NIH 3T3 cells
Authors: Kranewitter Wolfgang J , Gimona Mario
Published: July 2002

The Dbl family proto‐oncogene vav is a guanine nucleotide exchange factor (GEF) for Rho family GTPases. Deletion of the N‐terminus of Vav, harboring the single calponin homology (CH) domain, activates Vav's transforming potential, suggesting an important role of the CH domain in influencing Vav function. Since calponin binds actin, it has been suggested that the CH domain may mediate association with the actin cytoskeleton. In this study we have analyzed the subcellular localization and investigated the putative actin association of the Vav protein using enhanced green fluorescent protein (EGFP) fusion constructs. Our data show that both EGFP‐tagged full length Vav and the CH domain‐depleted EGFPvav 143–845 construct localize throughout the cytoplasm but fail to colocalize with F‐actin. However, the latter construct of Vav was more strongly retained in the Triton‐insoluble cytoskeleton fraction than full length Vav. Whereas removal of the CH domain had no apparent influence on the subcellular localization of Vav, deletion of the SH domains caused nuclear localization, indicating that Vav contains a functional nuclear localization signal. Expression of N‐terminally truncated Vav constructs caused depolarization of fibroblasts and triggered the bundling of actin stress fibers into parallel arrays in NIH 3T3 cells. Notably, the parallel actin bundles showed prolonged resistance to the actin polymerization antagonists cytochalasin B and latrunculin B. These data point towards a regulatory role for the CH domain in Vav and suggest an actin cross‐linking or bundling protein as a downstream effector molecule of vav‐mediated signalling pathways.
The human secretin receptor gene: genomic organization and promoter characterization
Authors: Ho Po-ki , Fong Rango S.M. , Kai Heidi S.T. , Lau Elisa H.Y. , Ngan Elly S.W. , Cotton Calvin U. , Chow Billy K.C.
Published: July 2002

Secretin is the most potent regulator of pancreatic bicarbonate, electrolyte and volume secretion. In this report, the organization of the human secretin receptor (hSR) gene was characterized by overlapping genomic phage clones. The hSR gene consists of 13 exons and 12 introns with all the splice donor and acceptor sites conforming to the canonical GT/AG rule. By transient reporter gene assays, the wild‐type promoter, containing 3.0 kb of the hSR gene 5′ flanking region, was able to drive 5.8±0.6 and 6.6±0.2‐fold (P<0.01) increases in luciferase activities in pancreatic ductule‐derived PANC‐1 and BPD‐1 cells, respectively. By subsequent 5′ and 3′ deletion analysis, a promoter element was identified within −408 to −158, relative to the ATG codon. This promoter element was found to be cell‐specific since it could drive reporter gene expression in PANC‐1 and BPD‐1 cells but not in Hs 262.St, Hs 746T and αT3‐1 cells. The study of the transcriptional control of human secretin and its receptor should shed light on the pathological developments of pancreatic cancer and autism in the future.
Induction of myelin gene expression in Schwann cell cultures by an interleukin‐6 receptor‐interleukin‐6 chimera
Authors: Haggiag Shalom , Chebath Judith , Revel Michel
Published: July 2002

Expression of myelin basic protein (MBP) and Po gene products is induced during the final postnatal maturation of Schwann cells and reinduced during nerve regeneration. We show that a chimeric protein containing interleukin‐6 fused to its soluble receptor (IL6RIL6 chimera) induces MBP and Po RNAs and proteins in cultures of dorsal root ganglia (DRG) from 14 day old mouse embryos. Activation of gp130 signaling by IL6RIL6 appears comparable to cyclic AMP elevating agents to induce the myelin gene products in DRG and in pure Schwann cell cultures.
Role of the carboxyl‐terminal region, di‐leucine motif and cysteine residues in signalling and internalization of vasopressin V1a receptor
Authors: Preisser Laurence , Ancellin Nicolas , Michaelis Lucie , Creminon Christophe , Morel Alain , Corman Bruno
Published: July 2002

The structural requirements for internalization and signalling of the vasopressin V1a receptor were investigated in stably transfected HEK‐293 cells. Removal of the 51 C‐terminal amino acids did not affect vasopressin binding, calcium signalling, heterologous desensitization or internalization of the receptor. Deletion of 14 additional amino acids reduced vasopressin‐dependent calcium increase and impaired receptor internalization. Substitution of cysteines 371‐372 did not affect intracellular signalling, but decreased endocytosis by 26%. Substitution of the 361‐362 leucine by alanine residues reduced by 56% V1a receptor sequestration without affecting calcium signalling. These results indicate that di‐cysteine and mostly di‐leucine motifs present in the C‐terminal region of the V1a receptor are involved in its internalization.
Relationship between age, histological type, and size of ovarian tumors
Authors: Okugawa K , Hirakawa T , Fukushima K , Kamura T , Amada S , Nakano H
Published: July 2002

Objective: To clarify the relationship between age, histological type, and size of ovarian tumors. Method: A review was made of 1648 cases of histopathologically diagnosed ovarian tumors and tumor‐like lesions, and information on the age of the patients and size of the tumor was obtained. Statistical analysis was performed using Kruskal–Wallis tests or Mann–Whitney U‐tests. Results: There were 840 (51%) cases of benign tumors, 73 (4%) cases of tumors of low malignant potential (LMP), 268 (16%) cases of malignant tumors and 467 (28%) cases of tumor‐like lesions. The age of the patients was significantly different among tumor‐like lesions (34.6±8.1 years), benign tumors (39.8±16.4 years), LMP tumors (45.2±18.3 years) and malignant tumors (51.9±13.0 years) (P<0.0001). The maximum diameter of the tumors was significantly different among tumor‐like lesions (7.1±3.3 cm), benign tumors (10.9±5.6 cm), malignant tumors (13.6±6.5 cm) and LMP tumors (18.5±6.8 cm) (P<0.0001). Conclusion: The distribution of tumor histological type (tumor‐like lesions, benign, LMP and malignant) was correlated against patient age and lesion diameter, with tumors in older patients or larger tumors more likely to be malignant.
Pregnancy‐induced hypertension and hyaline membrane disease
Authors: Carvalho M.A. , Faúndes A. , Santos L.C.
Published: July 2002

Objectives: (1) To determine whether the incidence of hyaline membrane disease (HMD) is different among premature babies of pre‐eclamptic women and those of normotensive controls; (2) to determine the relative risk (RR) of HMD according to the severity of pre‐eclampsia and gestational age. Methods: A retrospective and prospective cohort of 271 pre‐eclamptic women and 271 normotensive controls, with gestational age between 28 and 34 weeks was studied, including only singleton pregnancies, live fetuses and well‐documented gestational age. Exclusion criteria were ruptured membranes > 24 h, other maternal diseases and previous use of corticosteroids. Statistical analysis included relative risk and multiple logistic regression model. Results: The RR of HMD for babies of pre‐eclamptic women was 0.96 (95% CI: 0.78–1.17), and remained unchanged after controlling for gestational age and multiple logistic regression analysis. Conclusion: Preterm babies of pre‐eclamptic mothers had the same probability of having HMD as newborns of normotensive mothers.
Maternal and neonatal outcome related to delivery time following premature rupture of membranes
Authors: Pajntar M. , Verdenik I.
Published: July 2002

Objective: To evaluate neonatal and maternal outcomes of PROM deliveries with regard to the time elapsed since preterm rupture of membranes (PROM) to delivery. Method: According to the time elapsed since PROM to delivery we divided all singleton deliveries with PROM after the completed 34th week of gestation (N = 35419), which occurred in Slovenia between 1988 and 1994, into four groups: within 12 h, within 13–24 h, within 25–48 h, and over 48 h after PROM. The analysis was focused on the management of labor, neonatal and maternal infections and perinatal hypoxia with regard to the elapsed time. The Kruskal‐Wallis analysis of variance, the Pearson chi‐square test, Spearman rank correlation test, and the logistic regression test were used. Results: With increasing time elapsed since PROM to delivery we found significantly increased incidences of induced labor, operative delivery, fetal distress, poorer fetal condition at birth, neonatal infections, and minor maternal infections. Conclusion: We may conclude that the best neonatal and maternal outcomes are obtained if delivery occurs within 12 h after PROM.
Radiographic aspects of office hysteroscopic tubal occlusion with siloxane intratubal devices (the Ovabloc® method)
Authors: van der Leij G , Lammes F.B
Published: July 2002

Objective: To evaluate the importance of radiographs in women sterilized with hysteroscopically applied siloxane intratubal devices (ITDs). Methods: A retrospective study of the frequency of abnormal radiographs in 500 women was carried out. The agreement in judging these radiographs and the expected reliability of the sterilization was measured. Results: Abnormal radiographs were mostly documented in the first 100 sterilization procedures. Agreement in judging the radiographs is substantial. Different agreements on the expected reliability are due to the difference in experience with this sterilization method. Conclusions: Four types of abnormal radiographs can be categorized. Judgment of the radiographs can easily be learned. For the assessment of the reliability, training is necessary.
Induction of labor with intravaginal administration of misoprostol
Authors: Rodrigues R , Nunes F , Tiago D , Avillez T , Vieira A , Meirinho M
Published: July 2002

Objective: The purpose of this study was to evaluate the efficacy and safety of intravaginal misoprostol for labor induction. Methods: 110 singleton term pregnancies with or without rupture of membranes were enrolled. Fractionated doses of misoprostol were applied (50–100 μg), every 6 h until a maximum of three doses or beginning of labor. Results: The average interval (±S.D.) from vaginal application to the beginning of active labor and to delivery were, respectively, 9.5±5.7 h and 14.8±9.5 h. Failed labor induction was observed in two cases (2%). Cesarean section rate was 14%. The incidence of tachysystole was 18% and hypersystole 4%, but these situations were associated with abnormal fetal heart rate pattern (hyperstimulation) in only 3%. No maternal side effects and neonatal adverse effects were noted. Conclusions: Intravaginal misoprostol administration with low doses is an effective and safe method for labor induction in term pregnancies, with or without rupture of membranes.
Polymorphism of the β3‐adrenergic‐receptor gene associated with maternal body weight gain and fetal body weight
Authors: Arakawa M , Kurabayashi T , Tomita M , Yahata T , Takakuwa K , Tanaka K
Published: July 2002

Objective: To investigate whether the polymorphism of the β3‐adrenergic‐receptor (β3‐AR) gene was associated with the maternal and fetal conditions during pregnancy. Method: The association between the genotypes of β3‐AR and clinical phenotypes during pregnancy was analyzed in 92 women (a total of 126 pregnancies). Result: The overall frequency of the Trp64Arg β3‐AR allele in 92 pregnant Japanese women was 20.7%. In 125 pregnancies, excluding one homozygote (51 heterozygote group and 74 wild‐type group), a significant difference in the maternal body weight gain during pregnancy was observed between the heterozygote group and wild‐type group. The heterozygote group had significantly higher neonatal body weights, neonatal body weight index values and placental weights compared with the wild‐type group. Conclusion: The Trp64Arg heterozygous mutation in the β3‐AR gene is associated with not only the increase in the body weight of pregnant Japanese women but also the increase in the weights of their neonate and placentas.
Pregnancy following cardiac valve replacement surgery
Authors: Suri V , Sawhney H , Vasishta K , Renuka T , Grover A
Published: July 2002

Objectives: To study the outcome of pregnancy in women with artificial heart valves and to compare the maternal and perinatal outcome in mechanical and bioprosthetic valves. Method: Retrospective analysis of 34 pregnancies in 29 women who conceived after cardiac valve replacement was carried out. Results: The majority of women (76.4%) delivered within 5 years of valve replacement. Anticoagulants were administered in 79.4% of pregnancies. Maternal mortality was 2.9% and maternal morbidity in the form of heart failure, atrial fibrillation, valve thrombosis, thromboembolism, bleeding complications and non‐functioning prostheses were 2.9%, 5.8%, 2.9%, 2.9%, 11.7% and 2.9%, respectively. The incidence of prematurity was 5.8% and small for gestational age babies was 11.7%. There was no case of abortion. Two babies (5.8%) were still born, one of which had malformations. Maternal complications were significantly higher in women with bioprostheses, though the complications were more grave in the mechanical prostheses group. The perinatal outcome was almost similar in both the groups. Conclusion: The perinatal outcome was not different in women with bioprosthetic valves from the ones with mechanical prostheses, but the maternal morbidity was more in women with bioprosthetic valves. Coumarin derivatives were safe and effective and did not lead to embryopathy.
Effect of a half dose of tamoxifen on proliferative activity in normal breast tissue
Authors: Bernardes J.R.M. , Nonogaki S. , Seixas M.T. , Rodrigues de Lima G. , Baracat E.C. , Gebrim L.H.
Published: July 2002

Objectives: To investigate the proliferative activity of the mammary gland epithelium and plasma levels of progesterone, estradiol, prolactin, luteinizing hormone (LH), follicle‐stimulating hormone (FSH) and sex hormone‐binding globulin (SHBG) in premenopausal women treated with 10 and 20 mg of tamoxifen (TAM) for 22 days. Patients and methods: A randomized double‐blind study was performed with 43 premenopausal women with a diagnosis of fibroadenoma of the breast. The patients were divided into three groups: A (n=15, placebo); B (n=15, TAM 10 mg/day) and C (n=13, TAM 20 mg/day). They started taking an oral dose of TAM or placebo on the very first day of the menstrual cycle. Lumpectomy was performed on the 22nd day of therapy. Normal breast tissue samples were collected during surgery, immediately immersed in 10% buffered formalin, processed for routine histology and immunohistochemistry for proliferating cell nuclear antigen (PCNA) detection. Two peripheral blood samples were collected, both on the 22nd day of the menstrual cycle, in order to evaluate the hormone levels. PCNA expressing epithelial cells were quantified by using a digital program Kontron Image System KS‐300 in 1000 cells (400×). Results: The percentage of cells expressing PCNA was significantly higher in the group receiving placebo (group A, 50.3%) when compared to groups receiving TAM 10 or 20 mg/day (group B, 24.1%; and group C, 23.2%, respectively) (P<0.001). Differences between groups B and C were not significant. Levels of progesterone, estradiol and SHBG were significantly higher in B and C groups compared to group A. Increasing concentrations of FSH (P<0.0045) and lower levels of prolactin (P<0.0055) were only found in the group receiving 20 mg/day of TAM (group C). Conclusions: A 22‐day TAM therapy, either with 10 or 20 mg/day, significantly reduced the PCNA expression and therefore the proliferative activity of the normal human breast tissue. Increasing levels of estradiol, progesterone and SHBG were associated with TAM therapy at 10 or 20 mg/day. However, a significant change of the level of FSH and prolactin was reached only with a 20‐mg/day dose.
Role of dihydropyridine‐sensitive calcium channels in meiosis and fertilization in the bivalve molluscs Ruditapes philippinarum and Crassostrea gigas
Authors: Leclerc Catherine , Guerrier Pierre , Moreau Marc
Published: July 2002

Prophase‐arrested oocytes of Ruditapes philippinarum can not be fertilized or stimulated by a depolarizing agent such as an excess of KCl, in contrast to the situation found in Crassostrea gigas. We have performed a comparative study between the two situations found in these species. In vitro, both of these oocytes can be triggered to reinitiate meiosis following a treatment by serotonin which promotes an intracellular calcium surge. Ruditapes and Crassostrea oocytes further arrest in metaphase I, at which stage they can be either activated by sperm or by excess KCl. These treatments trigger an intracellular calcium increase. This suggests that functional voltage‐operated Ca2+ channels are expressed in Ruditapes during the course of maturation between prophase and metaphase I. Results obtained using pharmacological tools and direct binding of specific dihydropyridines, strongly suggest that these channels are dihydropyridine‐sensitive calcium channels. In Ruditapes they become functional after 5‐HT stimulation, their number increasing before GVBD. In Crassostrea the dihydropyridine‐sensitive Ca2+ channels are already present at prophase stage and their density is constant from prophase to metaphase I. Moreover, we have shown for Ruditapes and Crassostrea that: 1) the addition of 10 μM of S(‐)BayK8644, an agonist of dihydropyridine‐sensitive calcium channels to metaphase‐arrested oocytes releases them from metaphase block; and 2) incubating these oocytes with nicardipine, a potent blocker of dihydropyridine‐sensitive Ca2+ channels, inhibits both their activation by excess KCl or fertilization. Taken together these data suggest that the absence of dihydropyridine‐sensitive Ca2+ channels in the membrane of prophase‐arrested oocytes of Ruditapes may account for their inability to be fertilized at this stage, while the presence of dihydropyridine‐sensitive Ca2+ channels in prophase‐arrested oocytes of Crassostrea may explain their fertilizability at this stage.
Reorganization of chromatin in Xenopus egg extracts: electron microscopic studies
Authors: Pyne Chandra K.
Published: July 2002

Summry— The structural basis of mitotic condensation of chromosomes is one of the problems of cell biology yet to be elucidated. A variety of approaches have been used to study this problem and a large number of hypotheses have been proposed to explain the different levels of compaction of chromatin. Xenopus egg extracts, now widely used to study various aspects of cell biology, provide a valuable tool to study mitotic condensation of chromosomes. No detailed study has however yet been reported on the submicroscopic organization of condensed chromosomes in vitro in egg extracts. We present here the results of our electron microscopic studies on the organization of condensed chromosomes in vitro, using demembranated sperm nuclei and mitotic (CSF‐arrested) extracts of Xenopus laevis eggs, clarified by high speed centrifugation. Upon introduction of sperm nuclei in egg extracts, the nuclei swell and the chromatin undergoes a rapid decondensation; at this stage the chromatin is formed of 10 nm fibrils. After longer incubation, the chromatin condenses, and by 2 h chromosomal structures can be visualized by staining with DAPI or Hoechst 33258. Our results on the organization of chromosomes in different stages of condensation are discussed in relation to the different hypotheses proposed to explain the process of mitotic condensation of chromosomes. Finally, this study demonstrates the feasibility of high‐resolution analysis of the process of chromosome condensation.
New observations of the nuclear division in Entamoeba histolytica. The chromosomes
Authors: Solis Francisco J. , Adams Henry P.
Published: July 2002

The morphologic organization of the nucleus and DNA during the nuclear division of Entamoeba histolytica was examined. The DNA of dividing amebic trophozoites was visualized with the fluorescent probe, Hoechst 33258 for light microscopy, and a DNA‐specific antibody and phosphotungstic acid for electron microscopy. These techniques demonstrated features of the dividing amebic nuclei and the presence of spherical DNA‐containing bodies corresponding to the condensed chromosomes. Based on light microscopy observations the number of chromosomes in E histolytica is five. Microtubules (MT) radiating from the microtubule organizing center (MTOC) were observed attached to the putative chromosomes.
Peripheral nerve lengthening by controlled isolated distraction: a new animal model
Authors: Kroeber Markus W. , Diao Edward , Hida Shin‐Ichi , Liebenberg Ellen
Published: July 2002

We have developed a simple and effective animal model to study the distraction neurogenesis utilizing the sciatic nervelengthening technique in rats. The model allows macroscopic, physiological, and histological evaluation of the distraction site. Fourteen adult Harlan Sprague Dawley rats (300–350 g) were used in this study. A 10 mm segment of the right sciatic nerve of each animal in the nerve‐lengthening group was resected. Gradual nerve lengthening was performed by advancing the proximal nerve stump at a rate of 1 mm/day. The proximal stump neuroma was then resected and a direct nerve anastomosis was performed. On the left side a standard autogenous nerve‐grafting procedure was performed with a 10 mm segment of sciatic nerve used as an in situ nerve graft. Three months after the second surgery, the sciatic nerves were exposed and investigated by gross observation and EMG followed by histological processing and tissue analysis. Neomicrovascularization was observed surrounding the sciatic nerve anastomosis in all five specimens of the nerve‐lengthening group as compared to the more white‐colored scar tissue that was observed in the nerve‐grafting group. The EMG results were similar for both groups. Histological studies of the lengthened nerves showed axon morphology equivalent to the grafted nerves. This study demonstrated a clear evidence of the successful nerve regeneration within a segmental nerve gap by nerve lengthening. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Adrenergic responses in human small arteries isolated from the femoral neck
Authors: Lundgaard Annette , Aalkjær Christian , Bünger Cody , Hansen Ebbe Stender
Published: July 2002

Many pathological bone conditions are accompanied by changes in bone perfusion. However, no method has yet allowed investigation of vascular reactivity in human bone tissue. In the present study, arterial segments (diameter ≈ 0.25 mm) were isolated from human bone biopsies and mounted as ring preparations in vitro. The viability of the arteries and the effects of adrenoceptor stimulations were investigated. Combined α‐ and β‐adrenoceptor stimulation (noradrenaline 10−8–10−5 M) and specific α1‐adrenoceptor stimulation (phenylephrine, 10−8–10−4.5 M) induced concentration‐dependent contractions in all arteries. Selective stimulation of α2‐receptors (B‐HT 933, 10−8–10−3.5 M) only induced contraction in three of eight arteries. Stimulation of β‐receptors with isoprenaline (10−6 M) resulted in vasorelaxation in 3 of 10 arteries. In all arteries, acetylcholine (10−10–10−5 M) induced vasorelaxation, demonstrating preserved function of the endothelium. The results suggest that primarily α1‐receptors are responsible for adrenoceptor induced vasoconstriction in human bone while functional α1‐ and β‐receptors may not be consistently expressed. The model is the first to allow investigations on vascular reactivity in human bone tissue and may become valuable for assessment of both normal and pathological bone physiology. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Expression of β‐ADRENERGIC receptors inthe rat uterus : effects of puberty and oestrogen treatmentduring prepubertal development
Authors: Brauer M.Mónica , Burnstock Geoffrey
Published: July 2002

The expression of β‐adrenoceptors in the rat uterus has been analysed duringthe peripubertal transition and following acute and chronic oestradiol treatment duringprepubertal development. The distribution and density of β‐adrenoceptors was assessedautoradiographically on cryostat tissue sections using [3H]‐dihydroalprenolol ([3H]‐DHA). Binding sites were localised in all the ages andexperimental situations examined and showed the following intensity of labelling : endometrialepithelium > longitudinal muscle layer > circular myometrial layer > endometrial stroma.Competition experiments with the selective antagonists ICI 118,551 and atenolol, showed thatmost of the β‐adrenoceptors in the uterus belong to the β2 receptorsubclass. In prepubertal animals, the density of [3H]‐DHA binding sites was extremelylow. Following puberty the density of binding sites showed a generalised increase. Acuteadmininstration of oestradiol at the end of the prepubertal period provoked an increase in thedensity of [3H]‐DHA binding sites in all uterine regions, but the levels of labelling werelower than in peripubertal animals at proestrus and oestrus. Following chronic oestrogentreatment during postnatal development, oestradiol increased further the density of [3H]‐DHA binding sites. Results are discussed considering both the endocrine and neuralchanges accompanying puberty and oestradiol treatment.
Morphological and morphometrical changes in dorsal root ganglion neurons innervating the regenerated lizard tail
Authors: Geuna Stefano , Borrione Paolo , Poncino Alessandro , Giacobini‐Robecchi Maria G.
Published: July 2002

The variations occurring in neurons from dorsal root ganglia that provide innervation to the regenerated tail of the lizard (vicarious ganglia) are analysed. Vicarious ganglion neurons, when compared to control ganglion neurons (i.e. ganglia from the same animal that were not involved in the reinnervation process), show a size increase of the soma (cell hypertrophy) which applies to all cell types and sub‐types. No statistically significant differences in the relative percentage of neurofilament‐poor (type D) and neurofilament‐rich (type L) neurons were found between vicarious dorsal root ganglia compared to controls in all animals. On the contrary, within L neuron sub‐types, a statistically significant increase in sub‐type L2 (very rich in neurofilaments), and the appearance of sub‐type L3 neuron which is not detectable in controls, were demonstrated in vicarious dorsal root ganglia. In spite of these variations in size and percentage distribution, no structural and ultrastructural differences of the various cell types and sub‐types are detectable, except for the appearance of the sub‐type L3 neurons. However, this neuron sub‐type might not be considered specific of hypertrophy since the same morphological features have been observed, in normal conditions, in lizard dorsal root ganglia from cervical and lumbar spinal levels that provide innervation to limb plexuses.