Definitions matter: detection rates and perinatal outcome for infants classified prenatally as having late fetal growth restriction using SMFM biometric vs ISUOG/Delphi consensus criteria

OBJECTIVES

Fetal growth restriction (FGR) is often secondary to placental dysfunction and is suspected prenatally based on biometric or circulatory abnormalities detected on ultrasound. The aims of this study were to compare the screening performance of the Society for Maternal-Fetal Medicine (SMFM) biometric criteria (estimated fetal weight (EFW) or abdominal circumference (AC) < 10th centile) with that of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)-endorsed Delphi consensus criteria for late FGR for delivery of a small-for-gestational-age (SGA) infant at term, emergency Cesarean section (CS) for non-reassuring fetal status (NRFS), perinatal mortality and composite severe neonatal morbidity.

METHODS

We classified retrospectively non-anomalous singleton infants as having late FGR (diagnosed ≥ 32 weeks) according to SMFM and ISUOG/Delphi criteria in a cohort of women who had been referred to the Mater Mother's Hospital, Brisbane, Australia and who delivered at term between January 2014 and December 2020. The study outcomes were delivery of a SGA infant (birth weight (BW) < 10th or < 3rd centile), emergency CS for NRFS, perinatal mortality (defined as stillbirth or neonatal death within 28 days of a live birth) and a composite of severe neonatal morbidity. We assessed the screening performance of various ultrasound variables by calculating the sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, false-positive and false-negative rates, positive likelihood ratio (LR+) and negative likelihood ratio.

RESULTS

The SMFM and ISUOG/Delphi consensus criteria collectively classified 1030 cases as having late FGR. Of these, 400 cases were classified by both SMFM and ISUOG/Delphi criteria, whilst 548 cases were classified using only SMFM criteria and 82 cases were classified only by ISUOG/Delphi criteria. Prenatal detection of late FGR by SMFM and ISUOG/Delphi criteria was associated with increased odds of delivery of an infant with BW < 10th centile (SMFM: adjusted odds ratio (aOR), 133.0 (95% CI, 94.7-186.6); ISUOG/Delphi: aOR, 69.5 (95% CI, 49.1-98.2)) or BW < 3rd centile (SMFM: aOR, 348.7 (95% CI, 242.6-501.2); ISUOG/Delphi: aOR, 215.4 (95% CI, 148.4-312.7)). Compared with the SMFM criteria, the ISUOG/Delphi criteria were associated with lower odds (aOR, 0.5 (95% CI, 0.3-0.8)) of predicting a SGA infant with BW < 10th centile, but higher odds of predicting emergency CS for NRFS (aOR, 2.30 (95% CI, 1.14-4.66)) and composite neonatal morbidity (aOR, 1.22 (95% CI, 1.05-1.41)). Both SMFM and ISUOG/Delphi criteria were associated with high LR+, specificity, PPV and NPV for the prediction of infants with BW < 10th and BW < 3rd centile. However, both methods functioned much less efficiently for the prediction of composite severe neonatal morbidity or emergency CS for NRFS, with LR+ < 10. The SMFM biometric criteria alone, particularly AC < 3rd centile, had the highest LR+ values for the prediction of perinatal mortality.

CONCLUSION

Both the SMFM and ISUOG/Delphi criteria had strong screening potential for the detection of infants with BW < 10th or < 3rd centile but not for adverse neonatal outcome. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Colonic microbiota can promote rapid local improvement of murine colitis by thioguanine independently of T lymphocytes and host metabolism

OBJECTIVE

Mercaptopurine (MP) and pro-drug azathioprine are 'first-line' oral therapies for maintaining remission in IBD. It is believed that their pharmacodynamic action is due to a slow cumulative decrease in activated lymphocytes homing to inflamed gut. We examined the role of host metabolism, lymphocytes and microbiome for the amelioration of colitis by the related thioguanine (TG).

DESIGN

C57Bl/6 mice with or without specific genes altered to elucidate mechanisms responsible for TG's actions were treated daily with oral or intrarectal TG, MP or water. Disease activity was scored daily. At sacrifice, colonic histology, cytokine message, caecal luminal and mucosal microbiomes were analysed.

RESULTS

Oral and intrarectal TG but not MP rapidly ameliorated spontaneous chronic colitis in Winnie mice (point mutation in Muc2 secretory mucin). TG ameliorated dextran sodium sulfate-induced chronic colitis in wild-type (WT) mice and in mice lacking T and B lymphocytes. Remarkably, colitis improved without immunosuppressive effects in the absence of host hypoxanthine (guanine) phosphoribosyltransferase (Hprt)-mediated conversion of TG to active drug, the thioguanine nucleotides (TGN). Colonic bacteria converted TG and less so MP to TGN, consistent with intestinal bacterial conversion of TG to so reduce inflammation in the mice lacking host Hprt. TG rapidly induced autophagic flux in epithelial, macrophage and WT but not Hprt^-/- fibroblast cell lines and augmented epithelial intracellular bacterial killing.

CONCLUSIONS

Treatment by TG is not necessarily dependent on the adaptive immune system. TG is a more efficacious treatment than MP in Winnie spontaneous colitis. Rapid local bacterial conversion of TG correlated with decreased intestinal inflammation and immune activation.

PARP-2 sustains erythropoiesis in mice by limiting replicative stress in erythroid progenitors

Erythropoiesis is a tightly regulated process in which multipotential hematopoietic stem cells produce mature red blood cells. Here we show that deletion of poly(ADP-ribose) polymerase-2 (PARP-2) in mice leads to chronic anemia at steady state, despite increased erythropoietin plasma levels, a phenomenon not observed in mice lacking PARP-1. Loss of PARP-2 causes shortened lifespan of erythrocytes and impaired differentiation of erythroid progenitors. In erythroblasts, PARP-2 deficiency triggers replicative stress, as indicated by the presence of micronuclei, the accumulation of γ-H2AX (phospho-histone H2AX) in S-phase cells and constitutive CHK1 and replication protein A phosphorylation. Transcriptome analyses revealed the activation of the p53-dependent DNA-damage response pathways in PARP-2-deficient cells, culminating in the upregulation of cell-cycle and cell death regulators, concomitant with G2/M arrest and apoptosis. Strikingly, while loss of the proapoptotic p53 target gene Puma restored hematocrit levels in the PARP-2-deficient mice, loss of the cell-cycle regulator and CDK inhibitor p21 leads to perinatal death by exacerbating impaired fetal liver erythropoiesis in PARP-2-deficient embryos. Although the anemia displayed by PARP-2-deficient mice is compatible with life, mice die rapidly when exposed to stress-induced enhanced hemolysis. Our results pinpoint an essential role for PARP-2 in erythropoiesis by limiting replicative stress that becomes essential in the absence of p21 and in the context of enhanced hemolysis, highlighting the potential effect that might arise from the design and use of PARP inhibitors that specifically inactivate PARP proteins.

[The role of PARP2 in DNA repair]

The genome stability of higher eukaryotes is mainly dependent on the functioning of the DNA repair systems. In turn, the precise regulation of each step of repair processes is required for efficient DNA repair. While at present the most pathways of DNA repair have been established already, but the mechanisms of DNA repair regulation are required further investigation. Poly(ADP-ribose)polymerases (PARPs) are widely considered as potential regulators of a DNA repair. The role of most prominent member of this protein family--PARP1--in DNA repair is intensively studied, while the literature data on participation in repair processes of PARP2--the closestPARP1 homolog--are poorly Sum- marized although a great body of information concerning PARP2 participation in DNA repair has accumulated.. Using PARP2-deficient model organisms and cell lines, their increased sensitivity to several DNA damage agents was elucidated. The accumulation of PARP2 at the DNA damage sites in cells was shown. There are data demonstrating protein-protein interaction of PARP2 with several base excision repair/single strand break repair and non-homologous end joining proteins. Most of the data on PARP2 role have been obtained in experiments with model organisms and cell lines so it is difficult to project the attribution of PARP2 influence to specific process in vivo. In this review, we tried to summarize data on PARP2 participation in DNA repair processes, including our recent results.

Diversity in HLA class I and class II in kidney donors and recipients according to race in KwaZulu-Natal (South Africa) implications for transplantation

HLA matching of donors and recipients plays a major role in the success of organ transplantation. Race differences in HLA have been reported elsewhere. Aim: To analyse the diversity of HLA Class I and Class II among kidney donors and recipients according to race. Methods: This is a retrospective study of HLA types of renal patients and kidney donors attending the Renal Unitat Addington and Inkosi Albert Luthuli Central Hospitals from 1985 to 2002. Class I HLA typing was done using serological methods while Class II HLA typing was done using serological or molecular methods at the Tissue Immunology Laboratory, South African National Blood Services, Durban, South Africa. Files for 470 individuals were reviewed. There were 143 Blacks, 169 Indians, 88 Whites and 70 Coloureds. All the files were included and analysed according to race. Results: HLA A locus, 18 distinct antigens were recorded in Black patients. In Indians, 17 antigens were recorded. In Whites, 16 antigens were observed and the most frequent were A2 (29%) and A1 (17%). For the HLA B locus, 29antigens were recorded in Blacks with the two most frequent being B58 (13%) and B44 (12.5%). In Indians, 28 antigens were recorded. For DR locus 29 distinct antigens were recorded. Conclusion: Race differences in the profile of HLA types are observed. This may render difficult HLA matching between donors and recipients in organ transplantation.

Recurrent intrahepatic dislocation of ventriculoperitoneal shunt

BACKGROUND

Dislocation of ventriculoperitoneal (VP) shunt catheters is a well known complication after treatment of cerebrospinal fluid disorders; however, secondary perforation of the liver capsule by the catheter is exceptional. The literature on VP shunt complications involving the liver, their possible pathomechanisms and minimally invasive recovery strategies in reference to our own experience is reviewed.

CASE REPORT

We present a patient who suffered penetration of the liver by the peritoneal catheter of her VP shunt. Causing intermittent epigastric pain, the shunt tip was found to have progressively dislocated into the liver, as documented by CT scans. A laparoscopic approach was indicated to recover the shunt. The peritoneal catheter was found to be covered by widespread adhesions, consistent with peritoneal fibrosis. After local adhesiolysis, it was successfully recovered without shunt dysfunction, hemorrhage of the liver, or biliary fistula. After 4 months, dislocation recurred with formation of a subdiaphragmatic pseudocapsule. Early formation of fibrosis was detected during laparoscopic revision surgery. Although bacterial smears from both laparoscopic surgeries did not show any pathological findings, the patient presented with an abscess in the Douglas pouch 4 months later. Coagulase-negative staphylococci were found on ultrasound-guided insertion of a pigtail catheter. The VP shunt had to be replaced by a ventriculoatrial shunt. The infection was treated successfully with piperacillin. The subsequent 6 months follow-up period was without adverse events.

CONCLUSION

The treatment of choice in this exceptional case of intrahepatic shunt dislocation was laparoscopic recovery of the catheter. Laparoscopy allowed good visualization during adhesiolysis, immediate exclusion of hemorrhage or bile fistula at the puncture site, as well as function control and safe deposition of the shunt tip. Chronic infection as an underlying cause of peritoneal fibrosis has to be ruled out.

No significant effect of orally administered chemokine receptor 1 antagonist on intercellular adhesion molecule-3 expression in relapsing—remitting multiple sclerosis patients

We investigated the expression of intercellular adhesion molecules ICAM-1 and ICAM-3 on peripheral blood mononuclear cells in a subgroup of 34 patients with relapsing-remitting multiple sclerosis who were treated orally with the chemokine receptor 1 antagonist BX 471 in a 16-week, randomised, double-blind, placebo-controlled phase II study. ICAM-1 and ICAM-3 expression was measured by flow cytometry at different time points during and after therapy and compared using multivariate analysis of variance and non-parametric Mann Whitney test. ICAM-3 expression on CD14 + peripheral blood mononuclear cells was increased in the verum group under therapy, but did not differ significantly between the verum and placebo groups. Most likely, this trend represents a small epiphenomenon only mediated by receptor cross-talk and feedback mechanisms.

Novel STAT3 target genes exert distinct roles in the inhibition of mesoderm and endoderm differentiation in cooperation with Nanog

Leukemia inhibitory factor (LIF) activates the transcription factor signal transducer and activator of transcription 3 (STAT3), which results in the maintenance of mouse embryonic stem cells in the pluripotent state by inhibiting both mesodermal and endodermal differentiation. How the LIF/STAT3 pathway inhibits commitment to both mesoderm and endoderm lineages is presently unknown. Using a hormone-dependent STAT3 and with microarray analysis, we identified 58 targets of STAT3 including 20 unknown genes. Functional analysis showed that 22 among the 23 STAT3 target genes analyzed contribute to the maintenance of the undifferentiated state, as evidenced by an increase in the frequency of differentiated colonies in a self-renewal assay and a concomitant elevation of early differentiation markers upon knockdown. Fourteen of them, including Dact1, Klf4, Klf5, Rgs16, Smad7, Ccrn4l, Cnnm1, Ocln, Ier3, Pim1, Cyr61, and Sgk, were also regulated by Nanog. Analysis of lineage-specific markers showed that the STAT3 target genes fell into three distinct categories, depending on their capacity to inhibit either mesoderm or endoderm differentiation or both. The identification of genes that harness self-renewal and are downstream targets of both STAT3 and Nanog shed light on the mechanisms underlying functional redundancy between STAT3 and Nanog in mouse embryonic stem cells.

Targeting of adenovirus vectors carrying a tumor cell-specific peptide: in vitro and in vivo studies

Previously, we have identified a tumor cell-specific peptide, HEW, by panning of phage display libraries on the human colorectal cancer cell line WiDr. In this report we demonstrate that this peptide can modify the infection properties of adenovirus vectors. Increased infectivity of replication-deficient adenovirus 5 vectors in WiDr cells was observed upon genetic insertion of the HEW peptide in the HI loop of the fiber knob. Moreover, whereas the coxsackie and adenovirus receptor (CAR)-ablating fiber mutation S408E abolished apparent infection in CAR-positive WiDr cells, the insertion of HEW completely restored infectivity toward these cells in vitro. To assess whether the de- and re-targeted infection profile was maintained in vivo, the fiber-modified adenovirus vectors were injected intratumorally or intravenously in WiDr tumor-bearing Swiss nu/nu mice. No significant differences in efficiency of infection could be observed suggesting alternative viral uptake mechanisms in vivo. Next, we have included the fiber shaft mutation S(*) in our studies, which was described to confer a de-targeted phenotype in vivo. Reduced gene transfer due to the S(*) mutation both in vitro and in vivo could be confirmed. Insertion of HEW in the HI knob loop of shaft-mutated fiber, however, did not rescue infectivity in target cells neither in vitro nor in vivo. We demonstrate the efficient ligand-mediated re-targeting of adenoviral vector infection to the human cancer cell line WiDr. The lack of apparent re-targeting in the in vivo situation is described.

Regulation of Nanog expression by phosphoinositide 3-kinase-dependent signaling in murine embryonic stem cells

Embryonic stem (ES) cell pluripotency is regulated by a combination of extrinsic and intrinsic factors. Previously we have demonstrated that phosphoinositide 3-kinase (PI3K)-dependent signaling is required for efficient self-renewal of murine ES cells. In the study presented here, we have investigated the downstream molecular mechanisms that contribute to the ability of PI3Ks to regulate pluripotency. We show that inhibition of PI3K activity with either pharmacological or genetic tools results in decreased expression of RNA for the homeodomain transcription factor Nanog and decreased Nanog protein levels. Inhibition of glycogen synthase kinase 3 (GSK-3) activity by PI3Ks plays a key role in regulation of Nanog expression, because blockade of GSK-3 activity effectively reversed the effects of PI3K inhibition on Nanog RNA, and protein expression and self-renewal under these circumstances were restored. Furthermore, GSK-3 mutants mimicked the effects of PI3K or GSK-3 inhibition on Nanog expression. Importantly, expression of an inducible form of Nanog prevented the loss of self-renewal observed upon inhibition of PI3Ks, supporting a functional relationship between PI3Ks and Nanog expression. In addition, expression of a number of putative Nanog target genes was sensitive to PI3K inhibition. Thus, the new evidence provided in this study shows that PI3K-dependent regulation of ES cell self-renewal is mediated, at least in part, by the ability of PI3K signaling to maintain Nanog expression. Regulation of GSK-3 activity by PI3Ks appears to play a key role in this process.

[Laparoscopic Janeway gastrostomy: an advantageous solution for self-sufficient enteral feeding]

INTRODUCTION

Laparoscopic gastrostomy according to Janeway (LGJ) is an alternative to percutaneous gastrostomy techniques.

METHODS

A series of 10 LGJ is reported. The laparoscopic technique involves an isoperistaltic tube of 6-7 cm of length and 10-12 mm of diameter is created by 2 applications of linear stapling and cutting device. The tube is led out, opened and fixed to the fascial and cutaneous planes and a Foley catheter is inserted.

RESULTS

Mean operation time was 35 minutes. There was no complication. The LGJ was indicated in 9 patients with tumour of the pharynx and 1 patient with encephalopathy.

CONCLUSION

The main drawback of the LGJ is the need of general anaesthesia. The main advantage is the creation by minimal invasive surgery of a permanent gastrostomy equipped with a removable catheter easily changeable by non specialized health professionals, and even by the patient himself.

[Two 150 years anniversaries: Claude Bernard's internal environment and Addison disease]

In 2005 two 150 years anniversaries, which essentially influenced the development of modern medicine will be celebrated. French physiologist Claude Bernard from College de France published his work "Lectures on Experimental Physiology, applied to medicine" and British medical doctor T. Addison described insufficiency of adrenal cortex, today known as Addison disease.

Intraperitoneal chemohyperthermia and attempted cytoreductive surgery in patients with peritoneal carcinomatosis of colorectal origin

BACKGROUND

Colorectal cancer with peritoneal carcinomatosis is usually considered incurable. The purpose of this study was to evaluate the efficacy of intraperitoneal chemohyperthermia (IPCH) following cytoreductive surgery in patients with colorectal carcinomatosis.

METHODS

Between January 1989 and August 2002, 53 patients (mean age 48.6 years) were treated by IPCH with mitomycin C. IPCH was performed in 34 patients following extensive cytoreductive surgery (more than two peritonectomy procedures). Five patients underwent two operations and one patient three operations.

RESULTS

Operative morbidity and mortality rates were 23 and 4 per cent respectively. At a median follow-up of 59.5 months, the overall median survival was 12.8 months. The extent of carcinomatosis, completeness of cytoreduction and histological differentiation were significant prognostic indicators by univariate analysis. The median survival was 32.9 months for patients whose resection was classified as completeness of cancer resection (CCR) 0 (complete cytoreduction), 12.5 months for those whose operation was CCR-1 (diameter of residual nodules 5 mm or less) and 8.1 months for patients who had a CCR-2 resection (diameter of residual nodules more than 5 mm) (P < 0.001). Completeness of cytoreduction was the only significant independent predictor of survival by multivariate analysis.

CONCLUSION

IPCH combined with cytoreductive surgery seems to be an effective therapy for carefully selected patients with carcinomatosis from colorectal cancer. This strategy was most effective in patients with carcinomatosis of limited tumour volume or when cytoreductive surgery allowed sufficient downstaging (residual tumour nodules smaller than 5 mm).

Cytoreductive surgery and intraperitoneal chemohyperthermia for peritoneal carcinomatosis arising from gastric cancer

HYPOTHESIS

The most common cause of palliative resection and recurrence in gastric cancer is peritoneal seeding. This study evaluates the efficacy of intraperitoneal chemohyperthermia after cytoreductive surgery in patients with peritoneal carcinomatosis arising from gastric cancer.

DESIGN

Prospective clinical trial.

SETTING

Surgical department at a university academic hospital.

PATIENTS

Forty-nine consecutive patients with peritoneal carcinomatosis treated between January 1, 1989, and February 29, 2000.

INTERVENTIONS

All patients underwent intraperitoneal chemohyperthermia with mitomycin C (40-60 mg); 21 patients had previously undergone extensive cytoreductive surgery.

MAIN OUTCOME MEASURES

Clinicopathologic factors that affect overall survival rates.

RESULTS

With median follow-up of 99 months, overall median survival was 10.3 months. Two factors were significant independent predictors of survival by multivariate analysis: preoperative ascites (P =.04) and completeness of cancer resection (CCR) by cytoreductive surgery (P<.001). Median survival was 21.3 months for patients with CCR-0 (macroscopic complete resection) or CCR-1 (diameter of residual nodules <5 mm) and 6.1 months for patients with CCR-2 (diameter of residual nodules >5 mm) (P<.001). Four patients survived longer than 5 years.

CONCLUSIONS

An aggressive management strategy combining intraperitoneal chemohyperthermia with cytoreductive surgery is effective for patients with peritoneal carcinomatosis arising from gastric cancer. In highly selected patients (good general status, resectable primary tumor, resectable peritoneal carcinomatosis), this therapy may result in long-term survival.

Poly(ADP-ribose) polymerase-1 (PARP-1) is required in murine cell lines for base excision repair of oxidative DNA damage in the absence of DNA polymerase beta

Oxidative DNA base damage is mainly corrected by the base excision repair (BER) pathway, which can be divided into two subpathways depending on the length of the resynthetized patch, either one nucleotide for short patch BER or several nucleotides for long patch BER. The role of proteins in the course of BER processes has been investigated in vitro using purified enzymes and cell-free extracts. In this study, we have investigated the repair of 8-oxo-7,8-dihydroguanine (8-oxoG) in vivo using wild-type, polymerase beta(-/-) (Polbeta(-/-)), poly(ADP-ribose) polymerase-1(-/-) (PARP-1(-/-)), and Polbeta(-/-)PARP-1(-/-) 3T3 cell lines. We used non replicating plasmids containing a 8-oxoG:C base pair to study the repair of the lesion located in a transcribed sequence (TS) or in a non-transcribed sequence (NTS). The results show that 8-oxoG repair in TS is not significantly impaired in cells deficient in Polbeta or PARP-1 or both. Whereas 8-oxoG repair in NTS is normal in Polbeta-null cells, it is delayed in PARP-1-null cells and greatly impaired in cells deficient in both Polbeta and PARP-1. The removal of 8-oxoG and presumably the cleavage at the resulting apurinic/apyrimidinic site are not affected in the PARP-1(-/-)Polbeta(-/-) cell lines. However, 8-oxoG repair is incomplete, yielding plasmid molecules with a nick at the site of the lesion. Therefore, PARP-1(-/-)Polbeta(-/-) cell lines cannot perform 5'-dRP removal and/or DNA repair synthesis. Furthermore, the poly(ADP-ribosyl)ation activity of PARP-1 is essential for 8-oxoG repair in a Polbeta(-/-) context, because expression of the catalytically inactive PARP-1 (E988K) mutant does not restore 8-oxoG repair, whereas an wild type PARP-1 does.

Ghrelin -- a new endogenous growth hormone secretagogue

Ghrelin is a new endogenous peptide, discovered in 1999 by Kojima et al., as the result of a search for an endogenous ligand for an orphan receptor of known structure and function. Ghrelin is composed of 28 amino acids and is produced mostly by cells of the stomach, hypothalamus, and hypophysis, but it has also been detected in other tissues. Its discovery is related to the development of a new hypothesis regarding the regulation of growth hormone secretion. It is an antagonist of somatostatin. Ghrelin activates the release of growth hormone from the somatotrophic cells of the hypophysis. It participates in the regulation of energy homeostasis, increases food intake, decreases energy output and exerts a lipogenetic effect. Its metabolic effects do not depend on the GH/IGF-I system, but are mediated by the NPY/Y1 and AGRP receptor system. Ghrelin influences the secretion and motility of the gastrointestinal tract, especially the stomach. The presence of ghrelin and its receptors has also been demonstrated in many other tissues. Its function in these tissues has not yet been studied, thus providing many possibilities for further research.

Tumor cell-targeting by phage-displayed peptides

We isolated cancer cell-specific phages by subtracting and selecting complex peptide display phage libraries on cultured human cancer cells. The best candidate was selected by performing three rounds of subtraction before each of five selections on the human colorectal WiDr cell line. The phage showed more than 1000-fold higher binding efficiency for WiDr cells when compared to five other human cancer cell lines, including two of colorectal origin, and when compared to wild-type M13 phage. Fifty-fold higher binding efficiency was also seen for a human breast cancer cell line. We show that the WiDr cell binding of the selected phage was efficiently competed by the synthetic peptide HEWSYLAPYPWF, predicted from the phage sequence. This confirms that the specificity of the peptide is independent of the display by the phage coat proteins. The identified peptide may target biomarkers linked to colorectal cancer, and thus be useful for designing gene transfer vectors as well as diagnostic and prognostic tools for this disease.

The role of dopamine in methylene blue-mediated inhibition of estradiol benzoate-induced anterior pituitary hyperplasia in rats

Recently, we demonstrated that methylene blue partially inhibited estradiol-benzoate-induced anterior pituitary hyperplasia in rats. Since central dopaminergic systems participate in the regulation of estrogen-induced anterior pituitary growth and tumor transformation, this study examined whether a 3-week treatment with methylene blue could affect anterior pituitary levels of dopamine (DA), dihydroxyphenylalanine (DOPA), and dihydroxyphenylacetic acid and dopamine (D-2) receptors in male rats. Compared to controls, methylene blue significantly decreased anterior pituitary weight, increased basal anterior pituitary DA levels, and inhibited estradiol benzoate-induced decreases in anterior pituitary DA concentrations. Furthermore, we found that methylene blue alone decreased anterior pituitary D-2 receptor number. Methylene blue given in combination with estradiol benzoate partially inhibited estradiol benzoate-induced anterior pituitary growth and estradiol benzoate-induced increases in D-2 receptor number. Estradiol benzoate-treated rats had significantly lower anterior pituitary DOPA accumulation after intraperitoneal administration of 3,4-hydroxybenzyl-hydrazine dihydrochloride (NSD-1015), an irreversible inhibitor of L-aromatic amino acid decarboxylase whereas methylene blue did not affect anterior pituitary DOPA accumulation when compared to controls. Methylene blue decreased anterior pituitary prolactin levels and inhibited increases in anterior pituitary prolactin after estradiol benzoate administration. The present results suggest that anterior pituitary DA may play an important role in estrogen-induced anterior pituitary hyperplasia and tumor formation and that antioxidant drugs such as methylene blue may attenuate estrogen-induced pituitary growth. This may occur via increases in anterior pituitary DA levels associated with down-regulation of anterior pituitary D-2 receptors.

A bidirectional promoter connects the poly(ADP-ribose) polymerase 2 (PARP-2) gene to the gene for RNase P RNA. structure and expression of the mouse PARP-2 gene

Poly(ADP-ribose) polymerase 2 (PARP-2) is a DNA damage-dependent enzyme that belongs to a growing family of enzymes seemingly involved in genome protection. To gain insight into the physiological role of PARP-2 and to investigate mechanisms of PARP-2 gene regulation, we cloned and characterized the murine PARP-2 gene. The PARP-2 gene consists of 16 exons and 15 introns spanning about 13 kilobase pairs. Interestingly, the PARP-2 gene lies head to head with the gene encoding the mouse RNase P RNA subunit. The distance between the transcription start sites of the PARP-2 and RNase P RNA genes is 114 base pairs. This suggested that regulation of the expression of both genes may be coordinated through a bi-directional promoter. The PARP-2/RNase P RNA gene organization is conserved in the human. To our knowledge, this is the first report of a RNA polymerase II gene and an RNA polymerase III gene sharing the same promoter region and potentially the same transcriptional control elements. Reporter gene constructs showed that the 113-base pair intergenic region was indeed sufficient for the expression of both genes and revealed the importance of both the TATA and the DSE/Oct-1 expression control elements for the PARP-2 gene transcription. The expression of both genes is clearly independently regulated. PARP-2 is expressed only in certain tissues, and RNase P RNA is expressed in all tissues. This suggests that both genes may be subjected to multiple levels of control and may be regulated by different factors in different cellular contexts.

[Endocrinology 1999-2000]

Long-lasting problem on the differentiation of adenohypophyseal cell, which prepares them for their specific tasks (somatotropic, lactotropic ect.), becomes elucidated after recognition of the differentiational effect of transcription factor Pit-1. Expression of that factor in somatotrops results in STH secretion, contrary to lactotrops producing prolactin. Subclinical hypothyreosis (increased TSH with normal T3 and T4) endangers vessel not because of hypercholesterolemia, but because of changes in the dynamics of the blood flow. The idea of cardiotropic effect of thyroidal hormones is supported by the finding that administration of trijodthyronine to children after the surgical correction of heart malformations (cardiopulmonary bypass) improves myocardial function--it elevates cardiac output and decreases requirements on the intensive care. Receptors for hormones in tissues are flexible, they can be "heterooligomers" for dopamine and somatostatin. Mutations of mineralocorticoid receptor may cause hypertension in pregnancy and progesterone receptors have several isoforms. Receptors can be also activated by short exposition to a hormone. Glucocorticoids have probably also membrane receptors. Diabetes mellitus "type I" needn't to be immunogenic and DM type II not only results from down-regulation of receptors and subsequent insulin resistance, but it can be also caused by defects in insulin secretion. Insulin has receptors in the brain and participates in the appetite regulation. The attempt to use "desensibilisation" by peroraly administered insulin in patients with immunogenic DM had no effect. Stress affects memory mechanisms, heavy emotional stress during gravidity can bring congenital malformations. The decrease of mental functions in aged women depends on the level of free estradiol (the fraction, which is not bound to plasma proteins). Activation of dopaminergic neurons can be achieved by neurotropic growth factors. Nesiritide is a recombinant brain natriuretic hormone successfully tested in heart failure. The role of leptin in the appetite regulation in man is still not clear, other signalling molecules may have also an effect, e.g., ghrelin, which primarily stimulates STH secretion and brings about weight gain. Sildenafil influences nitrergic neurons elsewhere than in penis, for example it has positive effects in patients with oesophageal achalasia.

[Pharmacologic control of hypophyseal tumors: interactions of estrogens, thyroid hormones, growth and anti-growth factors]

Estrogens are involved in anterior pituitary (AP) growth and tumor transformation of AP. Central dopaminergic and noradrenergic systems are probably most important systems in regulation of AP growth. Estrogen-induced AP growth is associated with decreased metabolism of central catecholamines and increased dopaminergic DA-2 receptors. Application of thyroid hormones or methylene blue prevents both estrogen-induced catecholaminergic inhibition and dopamine DA-2 receptors increment in the AP. The alone given methylene blue increases the dopaminergic activity and the binding sites for dopamine. The study of interaction of natural regulators or synthetic compounds with estrogen-induced pituitary growth will be of value to understand better mechanisms of pituitary tumor formation and possibly find new approaches towards treating patients with these tumors.

[Jugular lymph node metastasis of papillary thyroid gland carcinoma 10 years later]

We present a patient with occult papillary thyroid carcinoma, in whom a single nodal metastasis had been excised. Ten years later a nodal recurrence was diagnosed by ultrasound and fine needle aspiration cytology. The diagnosis of recurrence was erroneous, and we discuss the differential diagnostic problems, the natural course, and the adequate treatment of occult papillary microcarcinoma.

Base excision repair is impaired in mammalian cells lacking Poly(ADP-ribose) polymerase-1

In mammalian cells, damaged bases in DNA are corrected by the base excision repair pathway which is divided into two distinct pathways depending on the length of the resynthesized patch, replacement of one nucleotide for short-patch repair, and resynthesis of several nucleotides for long-patch repair. The involvement of poly(ADP-ribose) polymerase-1 (PARP-1) in both pathways has been investigated by using PARP-1-deficient cell extracts to repair single abasic sites derived from uracil or 8-oxoguanine located in a double-stranded circular plasmid. For both lesions, PARP-1-deficient cell extracts were about half as efficient as wild-type cells at the polymerization step of the short-patch repair synthesis, but were highly inefficient at the long-patch repair. We provided evidence that PARP-1 constitutively interacts with DNA polymerase beta. Using cell-free extracts from mouse embryonic cells deficient in DNA polymerase beta, we demonstrated that DNA polymerase beta is involved in the repair of uracil-derived AP sites via both the short and the long-patch repair pathways. When both PARP-1 and DNA polymerase beta were absent, the two repair pathways were dramatically affected, indicating that base excision repair was highly inefficient. These results show that PARP-1 is an active player in DNA base excision repair.

Interaction between serum leptin levels and hypothalamo-hypophyseal-thyroid axis in patients with anorexia nervosa

The main objective of the study was to evaluate the endocrinological picture of anorexia. Serum leptin levels are low in untreated anorexia nervosa (AN), but studies of the exact relationship between leptin, body weight and hormones of hypothalamo-hypophyseal-thyroid axis and the impact of refeeding in anorectics are limited. The sample consistent of 15 patients with anorexia nervosa before and 1 month after partial weight recovery, and 15 age-matched control subjects. The body mass index (BMI), leptin, plasma neuropeptide Y (NPY), serotonin, thyroxine (T4), triiodothyronine (T3) and reverse triiodothyronine (rT3) in serum were evaluated for each subject. The mean serum levels of leptin, T4, and T3 were significantly lower before weight recovery in 15 patients with AN than they were in control subjects. After partial weight recovery, basal T3 levels were unchanged and significantly lower than in controls. Basal T4 was even still more reduced, but we observed significantly elevated ratio of T3/T4 and reduced ratio rT3/T4 of in AN patients after gain recovery, indicating increased conversion of T4 to T3 than to rT3. The levels of serum leptin were low in AN, but after partial weight recovery slightly increased, and correlated with BMI. No differences were observed in serum NPY. Serum levels of IGF-1 and serotonin were lower in AN than in controls before and after partial weight gain. IGF-1 was slightly increased after partial weight gain. We did not find correlation between serum levels of leptin and serum T4. The low serum levels of T3 associated with chronic starvation were thought to be the result of impaired peripheral conversion of T4 to T3. However, decreased levels of T3 were still apparent even after a partial weight gain, and the concentration of T4 was even lower. The diminished serum level of TSH in AN, however, appeared to return to the level of controls. On the basis of these results, we assume that low serum levels of thyroid hormones in AN reflect a dysfunction of the HPT axis in AN patients. It is known that in man serum serotonin levels correlate positively with T3 levels. It is possible that the low serum levels of thyroid hormones in AN subjects result in low serum serotonin and its product, melatonin. While IGF-1 reflects the energy intake of the previous few weeks, the serum leptin concentration reflects the true status of the adipose stores, a fact that has useful clinical implications.

[Endocrinology 1998-1999]

In the cascade hormone--second messenger--cellular G-proteins (GTP binding proteins), impairment can occur also at the last step: Mutant G-proteins may amplify the response (e.g. hypophyseal and thyroid adenomas) or reduce it (pseudohypoparathyreosis, testitoxicosis). Other new group of diseases appears to be anexinopathy: Among anexins belong also lippocortins and impairments occur in the hemocoagulation. "Reverse endocrinology" is a process description when the recognition of receptor (called an "orphan receptor") comes earlier than that of the hormone: Such receptors are known for several steroid hormones, retinoids and eicosanoids and it appears they are important also in the metabolism of cholesterol. A single antigen--glutamic acid decarboxylase (GAD), can cause autoimmune disease as the immuno-dependent diabetes (IDDM). Treatment of the skin T-cell lymphoma by some retinoids can result in hypothyroidism. Retrotransposones are example of the human genome modification with yet unknown clinical manifestations. Hepatocytal growth factor reveals to be the hope for treatment of cirrhosis. Search for effective peroral insulin substitutes is at present based on testing of various metabolites of fungi. Antibodies against TNF (tumor necrosis factor) become tested as "anti-cytokine therapy" in patients with rheumatoid arthritis. Some other suggestions for new ways of treatment is also listed, including the intranasal administration of estradiol.

A new mechanism for the control of a prokaryotic transcriptional regulator: antagonistic binding of positive and negative effectors

MalT, the transcriptional activator of the Escherichia coli maltose regulon, self-associates, binds promoter DNA and activates initiation of transcription only in the presence of ATP and maltotriose, the inducer. In vivo studies have revealed that MalT action is negatively controlled by the MalY protein. Using a biochemical approach, we analyse here the mechanism whereby MalY represses MalT activity. We show that MalY inhibits transcription activation by MalT in a purified transcription system. In vitro, a constitutive MalT variant (which is partially active in the absence of maltotriose) is less sensitive than wild-type MalT to repression by MalY, as observed in vivo. We demonstrate that MalY forms a complex with MalT only in the absence of maltotriose and that, conversely, MalY inhibits maltotriose binding by MalT. Together, these results establish that MalY acts directly upon MalT without the help of any factor, and that MalY is a negative effector of MalT competing with the inducer for MalT binding.

Self-association of the Escherichia coli transcription activator MalT in the presence of maltotriose and ATP

MalT, the transcriptional activator of the Escherichia coli maltose regulon, binds the MalT-dependent promoters and activates transcription initiation only in the presence of maltotriose and ATP (or adenylyl imidodiphosphate (AMP-PNP)). Cooperative binding of MalT to the array of cognate sites present in the MalT-dependent promoters suggests that promoter binding involves MalT oligomerization. Gel filtration and sedimentation experiments were used to analyze the quaternary structure of MalT in solution in the absence or presence of maltotriose and/or AMP-PNP, ATP, or ADP. The protein is monomeric in the absence of ligands and in the presence of ADP. In the presence of maltotriose, AMP-PNP, or ATP only, the protein self-associates, but a large fraction of the protein remains monomeric. In the presence of both maltotriose and AMP-PNP (ATP or ADP), the protein is essentially oligomeric, with the difference being that the oligomerization is less favored in the presence of ADP + maltotriose than in the presence of AMP-PNP + maltotriose. We present evidence that the association pathway comprises the following steps: monomers --> dimers --> (MalT)(n) --> aggregates, where 3 </= n </= 6. From these data, we conclude that the role of maltotriose and ATP as positive effectors is to induce the multimerization of MalT, and hence its cooperative binding to the mal promoters.

PARP-2, A novel mammalian DNA damage-dependent poly(ADP-ribose) polymerase

Poly(ADP-ribosylation) is a post-translational modification of nuclear proteins in response to DNA damage that activates the base excision repair machinery. Poly(ADP-ribose) polymerase which we will now call PARP-1, has been the only known enzyme of this type for over 30 years. Here, we describe a cDNA encoding a 62-kDa protein that shares considerable homology with the catalytic domain of PARP-1 and also contains a basic DNA-binding domain. We propose to call this enzyme poly(ADP-ribose) polymerase 2 (PARP-2). The PARP-2 gene maps to chromosome 14C1 and 14q11.2 in mouse and human, respectively. Purified recombinant mouse PARP-2 is a damaged DNA-binding protein in vitro and catalyzes the formation of poly(ADP-ribose) polymers in a DNA-dependent manner. PARP-2 displays automodification properties similar to PARP-1. The protein is localized in the nucleus in vivo and may account for the residual poly(ADP-ribose) synthesis observed in PARP-1-deficient cells, treated with alkylating agents or hydrogen peroxide.

[Endocrinology 1997-1998]

The author presents an account on advances in endocrinology in 1997-1998, starting by mentioning the Nobel prize for physiology and medicine in 1998 and the discovery of nitric oxide as an active substance. Subsequently the author discusses data on "new gerontology", i.e. hormonal aspects of the menopause, andropause, adrenopause and somatopause. Endocrinological contributions to oncology pertain in particular to the discovery of active substances which inhibit neovascularization (endostatins) and some new aspects of the action of antioestrogens and oestrogens. The possible action of hormonal factors in neurodegenerative processes are obvious in ubiquitine, CREB and "heat shock proteins". New types of Ca-channels were detected, in particular "promiscuous" channels, conveying Ca as well as Na, which can be influenced by endogenous ouabain. Subsequently attention is paid to ryanodine receptors and compounds acting as Ca on the sensor for Ca in the parathyroid bodies and inhibition parathormone secretion. The greatest future advances will be achieved obviously in the sphere of oncology, gerontology and hormonal analogues with unforeseen effects.

Involvement of poly(ADP-ribose) polymerase in base excision repair

Poly(ADP-ribose) polymerase (PARP) is a zinc-finger DNA binding protein that detects and signals DNA strand breaks generated directly or indirectly by genotoxic agents. In response to these lesions, the immediate poly(ADP-ribosylation) of nuclear proteins converts DNA interruptions into intracellular signals that activate DNA repair or cell death programs. To elucidate the biological function of PARP in vivo, the mouse PARP gene was inactivated by homologous recombination to generate mice lacking a functional PARP gene. PARP knockout mice and the derived mouse embryonic fibroblasts (MEFs) were acutely sensitive to monofunctional alkylating agents and gamma-irradiation demonstrating that PARP is involved in recovery from DNA damage that triggers the base excision repair (BER) process. To address the issue of the role of PARP in BER, the ability of PARP-deficient mammalian cell extracts to repair a single abasic site present on a circular duplex plasmid molecule was tested in a standard in vitro repair assay. The results clearly demonstrate, for the first time, the involvement of PARP in the DNA synthesis step of the base excision repair process.

Estrogenic effect of estradiol-sulfamate on the male rat anterior pituitary

Estrogen sulfamates (ES) are used for a new treatment strategy to avoid liver-hormone and hormone-liver interactions. ES represent new synthetic steroids having an increased systemic and reduced hepatic estrogenicity when given orally [1,2]. In the present study effects of ES and estradiol-benzoate (EB) on adenohypophyseal (AP) and serum concentrations of prolactin (PRL), luteinizing hormone (LH), and pituitary contents of cAMP and cGMP in the male rat are demonstrated. The weight gain of experimental animals treated by ES, EB or both hormones simultaneously was significantly lower compared to controls. EB but not ES significantly increased the weight of the AP. The amounts of PRL in the AP and serum were significantly increased after EB administration. ES significantly increased only AP content of PRL. EB administered simultaneously with ES exhibited an additive effect on the AP plasma concentrations of PRL. The EB or ES significantly decreased AP and serum concentrations of LH. ES given simultaneously with EB further decreased AP and serum concentrations of LH. After administration of either ES or EB, AP contents of cAMP and cGMP were significantly increased. An additive effect of these estrogens on the cGMP content was found. ES given simultaneously with EB further increased cGMP content in the AP but partially inhibited the effect of EB on the AP cAMP content. The present results demonstrate that the effects of ES on the AP content of PRL, LH, cAMP, and cGMP differ from the effects of EB. Whether this is due to lower levels of estradiol after the administration of ES secondary to its different absorption when compared to EB is unknown. Thus, our data support the concept that the ES has a lesser estrogenic effect on the AP function.

Lasp-1, a novel type of actin-binding protein accumulating in cell membrane extensions

The Lasp-1 gene, which has been localized to the q12-q21 region of human chromosome 17, is amplified and overexpressed in human breast cancers. In addition to the previously reported LIM and SH3 domains of Lasp-1, we report here the identification of an actin-binding domain in the core of the protein. This domain is functional as we demonstrate that Lasp-1 binds actin in vivo and in vitro. In addition, confocal analysis of the Lasp-1 subcellular distribution shows that the protein is colocalized with actin at peripheral cell extensions in individual epithelial cancer cells and in transformed fibroblastic cells. Moreover, Lasp-1 is tyrosine phosphorylated in fibroblast cell lines transformed by a constitutively active form of c-Src (c-SrcY527F). Altogether, our results show that Lasp-1 defines a new type of actin-binding protein and suggest that the protein may play a role in a signaling pathway involved in the organization of the cytoskeleton.

Possible participation of EDRF-NO in the hormonal regulation of bone blood flow in rats

An increase in bone blood flow (BBF) was observed in rats after castration whereas a decrease in BBF occurred after oestradiol or testosterone. The possible participation of prostaglandins in these changes was demonstrated. The present results show that the endothelium-derived relaxing factor, i. e. nitric oxide (EDRF-NO), might play a role in these hormonal actions on BBF. Until now, almost nothing is known about the possible action of NO on bone circulation. Methylene blue (MB) as a substance blocking EDRF-NO was administered to sham-operated or oophorectomized (OOX) female rats. We determined local blood flow (85Sr-microsphere uptake), cardiac output, blood pressure, heart rate, density of the tibia and ash weight, as well as 24-h incorporation of 45Ca and 3H-proline into the tibia. The administration of MB (0.5% in the food for 4 weeks) significantly lowered both 85Sr-microsphere uptake and blood flow values in the tibia and distal femur of sham-operated and OOX rats. MB lowered cardiac output and blood pressure to the same extent, indicating no change in the vascular resistance. After the administration of MB (0.1% in the food), 85Sr-microsphere uptake decreased significantly in the tibia of OOX females while no significant change was found in soft tissues. Bone density and ash weight were significantly lower in OOX rats and in sham-operated rats after MB treatment. Finally, the 24-h incorporation of both 45Ca and 3H-proline decreased significantly in OOX females after MB administration (0.04% in the food). It can be concluded that 1) MB lowers BBF, suggesting the participation of EDRF-NO in BBF regulation, 2) MB does not influence or may even suppress cardiac output and blood pressure in high dosage, 3) MB lowers 24-hour incorporation of 45Ca and 3H-proline into the tibia of OOX rats, which is in agreement with the circulatory effect, 4) MB lowers bone density and ash weight of the tibia in non-castrated female rats. The effects of MB observed in our experiments partially differ from those of arginine-derived blocking agents. This requires further elucidation.

The decrease of serum leptin levels in oestrogen-treated male mice

Adipocyte hormone leptin (OB protein) is considered to be an "adiposity signal" regulating body weight homeostasis and energy balance. We have previously reported that oestrogens (oestradiol-benzoate) significantly decrease the body weight in male rats, increase anterior pituitary and serum levels of the intracellular messenger cAMP, which activates cAMP-dependent protein kinase A, their targets include hormone-sensitive lipase and they influence the brain sympathetic system. The present study tested our hypothesis that oestrogens could influence serum leptin levels in male mice. We found that chronic administration of oestradiol-benzoate significantly attenuated serum levels of leptin, in the dependence on the duration of its administration, and simultaneously decreased body weight. We suppose that oestrogens affect leptin levels interacting with the signal transmission system of cAMP, possibly at the genome level. Our observations that the food consumption of mice with simultaneously decreased body weight and levels of serum leptin support the idea that there exists a satiety factor that counters the effect of low leptin.

Independence of estrogen-induced pituitary proliferation on local IGF-I mRNA and EGF mRNA expression. Modifying effects of tamoxifen and terguride

Pituitary hyperplasia as well as proliferation of the endometrium are typical responses to estrogen administration in rodents. Both insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) have been implicated as paracrine mediators and amplifiers of estrogen action in the rodent uterus. The auto/paracrine role of IGF-I, EGF, their receptors and IGF binding proteins in pituitary proliferation has not yet been solved. Here we have used a semi-quantitative reverse transcription polymerase chain reaction (RT PCR) assay to demonstrate the changes in IGF-I mRNA and EGF mRNA abundance in the proliferating male rat pituitary in response to estradiol benzoate (EB; 1 mg/kg b.w. twice weekly i.m. for 3 weeks) and modifying effect of drugs antagonizing the pituitary enlargement - antiestrogen tamoxifen (TAM, 5 mg/kg b.w. daily) and also the dopaminergic agonist terguride (TER, 0.66 mg/kg b.w. daily, routinely used for the treatment of prolactinomas). In three separate experiments, EB induced a 2.2-2.5 fold increase in pituitary weight. The abundance of IGF-I and EGF mRNAs in pituitaries of EB-treated animals did not differ from the controls in two experiments and in the third series with the most marked pituitary hyperplasia mRNAs of both growth factors were even significantly decreased. Antiestrogen TAM administered with EB partially blocked the EB-induced proliferation and significantly stimulated IGF-I mRNA (p=0.003) and EGF mRNA (p=0.023) expression, while EB or TAM alone did not stimulate mRNAs of the studied growth factors. Significant antiproliferative effect of dopaminergic agonist TER on EB-induced pituitary proliferation (p=0.006) was accompanied with decreased IGF-I mRNA (p=0.025), but not EGF mRNA abundance. Our results suggest that the estrogen-induced pituitary proliferation is independent of the local expression of IGF-I and EGF mRNAs.

[The effect of an NO-synthase inhibitor, methylene blue, on the function of certain endocrine glands]

Methylene blue is a thiazine dye, which has been used in the clinical medicine as disinfection agent and in treatment of methemoglobinemia. The recent investigations showed that this dye is able to inhibit the activation of guanylate cyclase pathway in the guanylate cyclase or in the NO-synthase level. This paper summarizes the experimentally obtained results concerning the influence of methylene blue on the hypothalamic, hypophyseal, thyroid and testicular function in rats. The possible mechanism of its influence with potential role of nitric oxide in the modulation of regulating pathways in these endocrine glands is discussed.

XRCC1 is specifically associated with poly(ADP-ribose) polymerase and negatively regulates its activity following DNA damage

Poly(ADP-ribose) polymerase (PARP; EC 2.4.2.30) is a zinc-finger DNA-binding protein that detects and signals DNA strand breaks generated directly or indirectly by genotoxic agents. In response to these breaks, the immediate poly(ADP-ribosyl)ation of nuclear proteins involved in chromatin architecture and DNA metabolism converts DNA damage into intracellular signals that can activate DNA repair programs or cell death options. To have greater insight into the physiological function of this enzyme, we have used the two-hybrid system to find genes encoding proteins putatively interacting with PARP. We have identified a physical association between PARP and the base excision repair (BER) protein XRCC1 (X-ray repair cross-complementing 1) in the Saccharomyces cerevisiae system, which was further confirmed to exist in mammalian cells. XRCC1 interacts with PARP by its central region (amino acids 301 to 402), which contains a BRCT (BRCA1 C terminus) module, a widespread motif in DNA repair and DNA damage-responsive cell cycle checkpoint proteins. Overexpression of XRCC1 in Cos-7 or HeLa cells dramatically decreases PARP activity in vivo, reinforcing the potential protective function of PARP at DNA breaks. Given that XRCC1 is also associated with DNA ligase III via a second BRCT module and with DNA polymerase beta, our results provide strong evidence that PARP is a member of a BER multiprotein complex involved in the detection of DNA interruptions and possibly in the recruitment of XRCC1 and its partners for efficient processing of these breaks in a coordinated manner. The modular organizations of these interactors, associated with small conserved domains, may contribute to increasing the efficiency of the overall pathway.

[Endocrinology 1996-1997]

Post-traumatic stress-induced disorders are still the focus of interest and most recently discussions are under way whether stress-induced cortisol excess leads to atrophy of the brain. In investigation on carcinogenesis the first reports were published on the use of antisense-oligonucleotides during inhibition of the development of tumours by a humoral mechanism and on the gene-based neuroendocrine differentiation of the lungs, perhaps associated with the basis for the development of small cell carcinoma. The oncogenic action of superoxides has also humoral mediators. Interest in nitrogen oxide is focused on two areas: inflammations and hypertension. Intraluminal NO concentrations increase in asthma 2-10x, in cystitis 30-100x, in Crohn's disease 20-200x. Humoral mechanisms in asthma offer new drugs--inhibitors of the development or action of leucotrienes. The basal NO production is reduced in "essential" hypertension but it is not known whether it is the cause or consequence. IGF-I increases the formation of NO in the vascular wall and thus perhaps reduces vascular contractility. As far as IGF is concerned, it is obvious that if recombinant preparations will be available, they will be tested in amyotrophic lateral sclerosis, myotonic dystrophy, multiple sclerosis, catabolic conditions, osteoporosis, in renal failure and to promote wound healing. STH may also prove useful in cardiac failure, in particular in cardiac cachexia. That TRH has receptors in the gut is not surprising, it acts, however, even there via TSH. Thrombopoietin is being tested in clinical trials. Neocytolysis is a new phenomenon: when erythropoietin secretion declines new erythrocytes disappear and only old ones remain in the blood stream. Alpha-adducin is a renal tubular protein, regulating the sodium balance.

The changes of the thyroid function and serum testosterone levels after long-term L-NAME treatment in male rats

Nitric oxide is a highly reactive gas that is produced by many tissues and exerts a series of physiological and pathophysiological effects. We studied the changes of the serum testosterone, thyroxine and thyrotropin levels, thyroid and anterior pituitary weights and thyroid cGMP concentrations in male Wistar strain rats treated with estradiol benzoate (EB) (1 mg/kg, im twice a week) and nonselective NO-synthase inhibitor L-NAME (N-omega-nitro-L-arginine methyl ester) alone and with combination of these substances. We have found that L-NAME in a dose 100 mg/kg/day but not in a dose 50 mg/kg/day increased the serum thyroxine and testosterone levels and in the case of testosterone in a higher dose partially blocked its drop when administered simultaneously with EB. The serum thyrotropin levels significantly fell after L-NAME and EB treatment. The cGMP thyroid levels changed only slightly in groups treated EB and L-NAME alone and were significantly decreased in group treated with combination of these substances. The nitric oxide thus seems to be an important modulator of thyroid and testicular function. The cGMP activation cascade is not probably involved in the nitric oxide induced changes of thyroid function.

[Hormonally active peptides]

The article reviews hormonally active peptides, mechanisms of their biosynthesis and chemical synthesis. Special attention is given to achievements of the Czech school of peptidology. Mechanisms of activity of peptidergic hormones is based mainly on the activation of adenylatcyclase and formation of the "second messenger", cAMP. Other three possible mechanisms are also reviewed. Main groups of peptidergic hormones (neurohypophyseal hormones, hypothalamic regulatory hormones, gastrointestinal hormones, natriuretic peptides, and many others) are described and their therapeutic and diagnostic significance is summarised. Future prospects of peptidology in the clinical praxis are briefly reviewed.

[The effect of phytogenic brassinosteroid steroidal hormones on transport of 86Rb+ ions into human erythrocytes]

The uptake of 86Rb+ ions by human erythrocytes as the measure of inhibition or stimulation of Na+, K(+)-ATPase by synthetic brassinolides, steroid fytohormonal promotors, was determined. No compound of the 12 tested brassinosteroids exerted higher inhibition of ATPase than digitoxin. A lower but significant inhibition of ion transport by 3 of tested derivatives, and a stimulation by 4 compounds was found. All active compounds were steroids with a 7-membered B-ring with an oxygen atom in the position 7a and with an oxogroup in position 6, i.e. they contained an lactone ring which is characteristic for natural brassinosteroids.

[Changes in thyroid function in rats after administration of methylene blue and interactions with estrogens and acetylsalicylic acid]

We have studied the thyroxine and triiodothyronine concentrations in male rats--the control, groups treated separately with estradiol benzoate, acetylsalicylic acid and methylene blue and with combinations of these substances. We have found out that the treatment with acetylsalicylic acid significantly lowers the thyroxine and triiodothyronine serum concentrations. The estradiol benzoate as well as methylene blue inhibited the drop in the serum thyroxine level when administered simultaneously with acetylsalicylic acid. The serum triiodothyronine decrease after acetylsalicylic acid treatment was inhibited by methylene blue and estradiol benzoate only in one of our two experiments. The simultaneous treatment with estradiol benzoate, acetylsalicylic acid and methylene blue did not change the triiodothyronine concentration comparing to control group and decreased the thyroxine serum concentration.

Chromosomal assignment and expression pattern of the murine Lasp-1 gene

The human Lasp-1 (LIM and SH3 protein) gene was previously identified by differential screening of a breast cancer-derived metastatic lymph node cDNA library. It was located on the q12-q21 region of human chromosome 17 and was shown to be amplified and overexpressed in 12% of breast tumors. Lasp-1 defines a new LIM-protein subfamily, as it associates a C-terminal Src homology 3 (SH3) domain to a N-terminal LIM motif. In this study, the isolation and characterization of the cDNA encoding the mouse Lasp-1 protein are described, and it is shown to be highly conserved with its human counterpart. In addition to the LIM and SH3 domains, both human and mouse Lasp-1 contain an actin-binding domain. The mouse gene was mapped by in situ hybridization to the 11C-11D region of chromosome 11. Northern blot analysis shows that this gene is expressed from 7.5 to 17.5 days post-coitum of mouse embryogenesis and in almost all adult tissues.