Mitochondrial protective effects of PARP-inhibition in hypertension-induced myocardial remodeling and in stressed cardiomyocytes

AIMS

During oxidative stress mitochondria become the main source of endogenous reactive oxygen species (ROS) production. In the present study, we aimed to clarify the effects of pharmacological PARP-1 inhibition on mitochondrial function and quality control processes.

MAIN METHODS

L-2286, a quinazoline-derivative PARP inhibitor, protects against cardiovascular remodeling and heart failure by favorable modulation of signaling routes. We examined the effects of PARP-1 inhibition on mitochondrial quality control processes and function in vivo and in vitro. Spontaneously hypertensive rats (SHRs) were treated with L-2286 or placebo. In the in vitro model, 150 μM H2O2 stress was applied on neonatal rat cardiomyocytes (NRCM).

KEY FINDINGS

PARP-inhibition prevented the development of left ventricular hypertrophy in SHRs. The interfibrillar mitochondrial network were less fragmented, the average mitochondrial size was bigger and showed higher cristae density compared to untreated SHRs. Dynamin related protein 1 (Drp1) translocation and therefore the fission of mitochondria was inhibited by L-2286 treatment. Moreover, L-2286 treatment increased the amount of fusion proteins (Opa1, Mfn2), thus preserving structural stability. PARP-inhibition also preserved the mitochondrial genome integrity. In addition, the mitochondrial biogenesis was also enhanced due to L-2286 treatment, leading to an overall increase in the ATP production and improvement in survival of stressed cells.

SIGNIFICANCE

Our results suggest that the modulation of mitochondrial dynamics and biogenesis can be a promising therapeutical target in hypertension-induced myocardial remodeling and heart failure.

0878 Association of Obstructive Sleep Apnea with Internalizing Symptoms vs. Externalizing Behaviors in Adolescents with Attention Deficit Hyperactivity Disorder

Introduction

Attention deficit hyperactivity disorder (ADHD) in children has been associated with insomnia, obstructive sleep apnea (OSA), and abnormal periodic limb movements (PLMS). However, there is lack of data examining the contribution of OSA to ADHD-related internalizing symptoms and externalizing behaviors in adolescents.

Methods

We studied the Penn State Child Cohort, a random general population sample of 700 children (8.7±1.7y), of whom 421 were followed-up 8.3 years later during adolescence (17.0±2.3y, 53.9% male). All adolescents underwent a 9-hour PSG, clinical history and physical examination. ADHD was ascertained by a parent- or self-report of having been diagnosed with ADHD. OSA was defined as an apnea hypopnea index (AHI) of ≥2 events per hour of sleep, while a periodic limb movement index (PLMI) ≥5 events per hour of sleep was indicative of PLMS. Controls, OSA-alone, ADHD-alone and ADHD+OSA were identified. The Child or Adult Behavior Checklist were used to ascertain internalizing and externalizing behaviors. Multivariable-adjusted models controlled for sex, race, age, and body mass index (BMI) percentile.

Results

As compared to controls, adolescents with ADHD-alone or ADHD+OSA had significantly greater externalizing behaviors (p<0.001), inattention (p<0.001) and thought problems (p<0.001). While adolescents with ADHD-alone had higher internalizing symptoms (p=0.021), specifically withdrawn-depression (p<0.01), adolescents with ADHD+OSA had more somatic problems than controls (p=0.048). There were no statistically significant differences in behavioral outcomes between controls and adolescents with OSA-alone or between adolescents with ADHD-alone and ADHD+OSA.

Conclusion

Adolescents with comorbid ADHD and OSA do not present with worse behavioral outcomes than those with ADHD alone. Future studies should examine whether the progression of these adolescents into young adulthood differs in terms of their behavioral outcomes and development of mental health disorders.

Support

National Institutes of Health (R01HL136587, R01HL97165, R01HL63772, UL1TR000127)

Comparison of volarly and dorsally displaced distal radius fracture treated by volar locking plate fixation

INTRODUCTION

In case of distal radius fractures (DRF) the distal fragment generally displaces either dorsally or volarly. Scientific literature however, seldom differentiates between volarly and dorsally displaced DRFs when reporting results. It is no clear, if the direction of displacement has an influence on the clinical and radiological outcome. This study was intended to evaluate the influence of displacement direction in adult patients with surgically treated Colles or Smith type fractures.

PATIENTS AND METHODS

After a mean follow up (FU) time of above 5 years, 50 patients who underwent open reduction and internal fixation for DRFs (25 Smith type fractures, 25 Colles type fractures) were included. Upon FU, standard X-rays and a clinical evaluation as well as evaluation scores were raised and analysed.

RESULTS

Clinical evaluation showed no difference between the Colles and the Smith group. Radiologic and clinical results for the Colles group showed diminished flexion compared to the healthy wrist, decreased radial inclination and dorsal tilt during FU and progression of osteoarthritis. For the Smith group decreased grip strength compared to the healthy wrist and osteoarthritis-progression was found. For both groups there was no correlation between radiologic values, grip strength, arthrosis grading, disability of arm, shoulder and hand score and patient rated wrist evaluation score.

DISCUSSION

Decreased flexion in combination with a decreased dorsopalmar tilt might hint towards a mechanical inhibition in the Colles group. Altogether, the study showed good clinical outcome with satisfactory radiological result. As all patients showed arthrosis progression, the fracture per se is to be seen as a prearthrotic factor. It still remains unclear which measures could be taken to prevent this.

17-β-estradiol Decreases Neutrophil Superoxide Production through Rac1

Neutrophil granulocytes form the biggest free radical producing system of the human body. The importance of this system in atherosclerotic plaque formation and other free radical mediated disorders is confirmed by both in vivo and in vitro studies. Estrogen's effect on free radical production involves multiple estrogen receptors and occurs both on transcriptional and on protein phosphorylational level. Estrogen decreases the superoxide production of neutrophil granulocytes in such a short time frame it is unlikely to be mediated by transcription regulation. We investigated the underlying mechanism through which the mentioned estrogen effect takes place using an immunabsorption-based method. Phosphorylation data of 43 different messenger proteins were used for pathway analysis. The newly identified pathway involved largely second messengers from previously described non-genomic estrogen effects and affected superoxide production via Rac1 - an important regulator of free radical production and chemotaxis. Selective inhibition of the participating second messengers altered superoxide production in the predicted direction confirming that this pathway is at least partly responsible for the effect of 17-β-estradiol on chemoattractant induced superoxide production.

Linear spin wave theory for single-Q incommensurate magnetic structures

Linear spin wave theory provides the leading term in the calculation of the excitation spectra of long-range ordered magnetic systems as a function of 1/√S. This term is acquired using the Holstein-Primakoff approximation of the spin operator and valid for small δS fluctuations of the ordered moment. We propose an algorithm that allows magnetic ground states with general moment directions and single-Q incommensurate ordering wave vector using a local coordinate transformation for every spin and a rotating coordinate transformation for the incommensurability. Finally we show, how our model can determine the spin wave spectrum of the magnetic C-site langasites with incommensurate order.

Magnetic soft modes in the distorted triangular antiferromagnet α-CaCr2O4

In this Letter, we explore the phase diagram and excitations of a distorted triangular lattice antiferromagnet. The unique two-dimensional distortion considered here is very different from the "isosceles"-type distortion that has been extensively investigated. We show that it is able to stabilize a 120° spin structure for a large range of exchange interaction values, while new structures are found for extreme distortions. A physical realization of this model is α-CaCr(2)O(4), which has a 120° structure but lies very close to the phase boundary. This is verified by inelastic neutron scattering which reveals unusual rotonlike minima at reciprocal space points different from those corresponding to the magnetic order.

NADPH-diaphorase expression in the rat jejunum after intestinal ischemia/reperfusion

The purpose of this study was to analyze the nicotinamide adenine dinucleotide phosphate - diaphorase (NADPH-d) activity in the rat jejunum after a mesenteric ischemia/reperfusion injury. Nitric oxide, synthetised from L-arginine by the enzyme nitric oxide synthase, is a nonadrenergic noncholinergic relaxant neurotransmitter of the intestinal smooth muscle. It plays an important role in the process of plasticity after the ischemia/reperfusion injury. Experimental animals were divided in two groups: the control group and the ischemic/reperfusion group, with different period of the reperfusion. The NADPH-d histochemical method has been used as a marker for the nitric oxide synthase. NADPH-d activity has been rapidly decreased in the neurons of both enteric nervous systems in plexuses of the jejunum after 1 h mesenteric ischemia and 1 h reperfusion. Differences were predominantly detected in the myenteric plexus; they were seen in change of the neuronal shape, in the arrangement of neurons and in intensity of their staining. The NADPH-d positivity was absent in the intestinal crypts. After 1 h ischemia and 24 h reperfusion, the NADPH-d activity was gradually increased, but it was lower in comparison with the control group. On the 30^th day following the ischemia/reperfusion there were no changes in NADPH-d positivity compared with the control animals. These results indicated that the jejunal ischemia/reperfusion has affected the neurons of the enteric nervous system of adult rats and resulted in the early decrease of NADPH-d positivity 1 h of the reperfusion insult. The gradual increasing of NADPH-d activity in 24 h following the reperfusion could be considered as a result of the plasticity process. On the 30^th day after the ischemia/reperfusion all histochemical changes were returned to the control levels.

Histochemical detection of monoamine oxidases in rat female genital organs during preimplantation period of pregnancy

OBJECTIVE

Localization of monoamine oxidases (MAO) in rat female gonads during preimplantation period of pregnancy was determined.

MATERIAL AND METHODS

Pregnant females were killed on their first, third, and fifth days of pregnancy and animals were transcardially perfused with PBS and fixative solutions. Ovaries, oviducts and uteri were immediately removed and they served for the determination of MAO localization employing the method of enzymatic histochemistry.

RESULTS

MAO-A activity in ovary was visible in corpora lutea and in interstitial gland cells while MAO-B was detected predominantly in blood vessels. Both MAO enzymes were seen in the smooth muscle fibers of the ovarian hilum. The presence of MAO enzymes was however not detected in follicles at any stage of their development. In oviduct and uterus, both MAO enzymes were visible in similar places, namely in smooth muscle fibers, mast cells and blood vessels, with no MAO presence seen in the epithelium.

CONCLUSIONS

Potential physiological importance of MAO localization in different cells of female reproductive organs during early period of pregnancy is proposed (Fig. 6, Ref. 29).

Elevated CREB activity in embryonic fibroblasts of gene-targeted histamine deficient mice

OBJECTIVES

Histamine is a known inducer of cAMP-responsive element binding protein (CREB), which plays a key role in initiation of adipogenesis. Our present goal was to study how histamine deficiency impacts CREB signalling and adipogenesis.

METHODS

We used a histidine-decarboxylase gene-targeted (HDC KO) mice model lacking endogenous histamine. We measured CREB activity and expression by EMSA, Western blot and real-time RT-PCR, as well as cAMP levels by ELISA in primary embryonic fibroblasts derived from WT and HDC KO mice. The ability of these cells to form adipocytes was also tested in preliminary experiments.

RESULTS

We found that in the absence of the histamine, cells show higher constitutive CREB activity and greatly increased intracellular cAMP levels, as well as that in contrast to WT cells, HDC KO fibroblasts are more prone to differentiate into adipocytes.

CONCLUSION

These data suggest a newly recognised inhibitory role for histamine in CREB activity and draws attention to the potential role of histamine in adipocyte differentiation.

Endobronchial actinomycosis presenting as haemoptysis

Actinomycosis is an infrequent chronic progressive granulomatous and suppurative disease caused by Actinomyces israelii, a natural inhabitant of the gastrointestinal tract. We report a rare case of a 68-year-old man with primary endobronchial actinomycosis who presented in the emergency respiratory ward with massive hemoptysis and dyspnea. An urgent fiberoptic bronchoscopy revealed hypertrophic mucosa and a narrowed lingular bronchus with a pale extruding exophyt. Diffuse bleeding from the mucosa adjacent to the exophyt was present. Histopathologic evaluation revealed chronic inflammation with abscess formation and clusters of Actinomyces colonies. Therapy with clindamycin maintained for 7 weeks prevented recurrence of the disease. In the light of our case and the review of literature we conclude that early recognition of primary endobronchial actinomycosis associated with hemoptysis and proper antibiotic treatment are essential to prevent undesirable complications including unwarranted surgery (Fig. 2, Ref. 30). Full Text (Free, PDF) www.bmj.sk.

Inhaled corticosteroids and survival in COPD patients receiving long-term home oxygen therapy

BACKGROUND

Several observational studies suggest that therapy with inhaled corticosteroids (ICS) is associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD). However, none of these has reported survival data in COPD patients with respiratory insufficiency who require domiciliary oxygen therapy. The present study was conducted to examine the association between ICS and all-cause mortality in patients with severe COPD and chronic hypoxemia.

PATIENTS AND METHODS

From a tertiary referral clinic, we identified 145 consecutive COPD patients who met the criteria for long-term oxygen therapy between 1996 and 2002. We compared the hazard ratio (HR) for all-cause mortality over 1 year between patients who were (n=55) and were not treated with ICS (n=90).

RESULTS

In a crude analysis, the use of ICS was associated with a HR of 0.38 (95% confidence interval (CI)=0.18-0.79). After adjustments for age, sex, use of oral steroids, and beta2-agonists, PaO2 and PaCO2, the HR was 0.46 (95% CI=0.21-0.98).

CONCLUSIONS

Our findings indicate that ICS may reduce all-cause mortality in patients with severe COPD and chronic hypoxemia, who require long-term domiciliary oxygen therapy. These data suggest that ICS may play an important role in improving clinical outcomes in patients with advanced COPD.

297A METHOD TO DRIVE CALCIUM SIGNALLING DYNAMICS IN FERTILIZED MOUSE EGGS

Following fertilization, eggs exhibit a series of repetitive increases in intracellular calcium that activate development. The developmental impact of the long-lasting series of Ca2+ signals is still a subject of controversy. Although several studies using parthenogenetically activated eggs suggest that Ca2+ dynamics affect post-implantation development, artificial stimulation of Ca2+ signaling after ICSI in bovine eggs shows that development still remains poor in comparison to fertilized eggs. Such divergence between parthenogenetic studies and those aimed at stimulating ICSI eggs makes it impossible to draw any conclusions regarding the function of Ca2+ signaling for two reasons. First, non-fertilized eggs do not release Ca2+ from intracellular stores and their development is compromised due to the absence of paternally-derived chromosomes. Second, because ICSI eggs are excitable, Ca2+ stimulation generates additional Ca2+ oscillations that might compromise their development. Moreover, in both cases, Ca2+ signaling is not physiological. To understand better the function of Ca2+ signaling at fertilization, we developed a new approach based on micro fluidic technology that makes it possible to drive Ca2+ signal dynamics of fertilized eggs with no apparent deleterious effects. This method relies on the fact that the properties of the IP3 receptor (IP3R) calcium channel are changed after fertilization, and IP3 and Ca2+ act as co-agonists to cause Ca2+-induced Ca2+ release (CICR) from intracellular stores. Because Ca2+ has both an inhibiting and a stimulating function, we exploited these opposing properties. First, we inhibited Ca2+ release by external washing with Ca2+-free medium;; this extra cellular washing decreases cytosolic [Ca2+]I, and facilitates dissociation of Ca2+ ions from the IP3R that in turn decreases the probability of IP3R channel opening. Second, once the IP3R is inhibited, a simple injection of Ca2+ ions by electropermeabilization triggers channel opening and induces Ca2+ release. Then, by just varying the time interval and the number of the electrical pulses, it is possible to drive the dynamics of the CICR process that initiates development. Intracellular Ca2+ imaging demonstrated that fertilized eggs subjected to 24 electrical pulses (1.45kVcm−1) every 8min for 3h in the microfluidic processor responded by exhibiting 24 induced-Ca2+ transients that are caused by calcium release from intracellular stores. All auto-regenerative responses between pulses were inhibited. Among 60 treated embryos transferred to pseudo-pregnant recipients, 40 (67%) developed to term, with birth of live offspring, thus demonstrating that this new methodology does not compromise development. Because the eggs are fertilized, it now becomes possible to study the function of Ca2+ signaling during egg activation and to evaluate its developmental impact, if any, in association with genomic approaches.

133SUBOPTIMAL OOCYTE ACTIVATION CAUSES METHYLATION CHANGE IN TWO IMPRINTED GENES IN THE MOUSE

In mammals, the dynamic of Ca2+ oscillations induced by fertilization causes the remodeling of the parental chromosomes and activates the developmental processes. The objective of the present study was to evaluate whether the modulation of the regime of Ca2+ oscillations during the process of egg activation is capable of inducing specific chromatin modification. The sensitivity of chromatin modification during oocyte activation was evaluated by comparison of the methylation profile of Igf2r, the maternal allele of which is methylated, and H19, the maternal allele of which is unmethylated. Freshly ovulated mouse oocytes were parthenogenetically activated by a series of repetitive Ca2+ ion influxes induced by electropermeabilization of the plasma membrane in a microfluidic processor. The first treatment (T1) consisted of 24 electrical pulses (1.45kVcm−1) given every 8min for 3h in the presence of 100μM of Ca2+. The treated oocytes were almost all activated, 98% (328/338), and formed pronuclei 3 or 4h after the first pulse. The second treatment (T2) was made up of 16 electrical pulses of lower amplitude (1.12kVcm−1), given every 8 min for 2h under the same conditions. The rate of egg activation dropped to 29%, (86/298), and the time course of pronucleus formation was completed 7h after the first pulse. The remaining oocytes, 71% (212/298), extruded the second polar body, but their chromatin did not undergo full decondensation and then did not proceed further to pronucleus formation. The methylation profiles of the two imprinted genes were analyzed by using the bisulfite sequencing method. Oocytes that formed pronuclei after being subjected to either the T1 or the T2 treatment displayed methylation profiles of the two alleles similar to those of the non-treated oocytes. The Igf2r-DMR was found fully methylated on all 13 copies examined, and the H19 DMR was found mostly unmethylated (13 out of 19 copies; 6 were partially methylated). Thus, when parthenogenetic activation results in formation of a pronucleus the methylation profile of these two genes is maintained. In contrast, those from oocytes that responded by PB extrusion showed the following: fully unmethylated Igf2r-DMR copies (9/9) and partially methylated H19-DMR copies (4/11). These results reveal that rapid de novo methylating and demethylating activity are present when cells are subjected to partial activation. Thus, when the biological response of the oocyte is incomplete, that is to say, when the chromatin remains partially decondensed after suboptimal activation, both active demethylation and de novo methylation can be remarkably dynamic. While the molecular mechanism needs to be clarified, these results reveal that modulation of the process of egg activation might give new opportunities to better understand the epigenetic chromatin changes caused by fertilization.

299OOCYTE ACTIVATION IS THE RESULT OF CALCIUM SIGNAL SUMMATION

Egg activation in mammals is caused by a series of cytosolic Ca2+ oscillations that are essential for development. However, the specific functional significance of the number or the frequency of the Ca2+ signals is not clear. The objective of this study was to determine whether the efficiency of egg activation relies on the frequency or on the number of signals. Given the repetitive nature of the signal, it is nearly impossible to discriminate the specific effect of the frequency from the number because increasing the time interval between signals directly reduces their number in a given time unit and vice versa. To bypass such difficulty, we subjected non-fertilized mouse oocytes, which are not capable of releasing Ca2+ from intracellular stores, to a coherent series of four treatments. Repetitive intracellular Ca2+ signals were introduced into freshly ovulated mouse oocytes by electropermeabilisation of Ca2+ ions by means of a microfluidic processor . The first regime (T1) was a monotonic [Ca2+]i increase lasting about 10min and provoked by 4 consecutive electrical pulses (1.45kVcm−1) given at 2-min intervals. This large calcium signal gave a poor activation rate: 6% (4/67). The second regime (T2) was made up of six lower pulses (1.12kVcm−1) given at 30-min intervals. The rate of egg activation reached 38% (75/195). The third treatment (T3) consisted in subjecting oocytes consecutively to the T1 and the T2 treatments. In that case, the egg activation reached 88% (121/138). The remarkable increase in egg activation efficiency can be attributed to the increase in the total [Ca2+]i load, which is the only change in T3. Thus, it appears that the large monotonic increase (T1) potentiates the response as revealed by the periodic stimulation delivered by T2. It therefore seems that the process downstream of the signal is incremental in nature, and entrance in interphase of the cell cycle is reached when the summation of individual signals reaches a sufficient level. We next evaluated whether the putative summation effect makes it possible to regularly get 100% of egg activation by increasing the cytosolic Ca2+load. Oocytes were subjected to a last treatment (T4) that consisted of T1 and then 24 pulses (1.45kVcm−1) given every 8min. In that case 100% of the oocytes were activated (80/80). Thus, it appears that all oocytes are subject to egg activation if they receive a sufficient amount of calcium signal. Moreover, the frequency does not seem to play a crucial role for entrance into interphase because reducing the time interval from 30min (T3) to 8min (T4) resulted in high activation rates in both cases (88% and 100%, respectively). The question remains as to whether the distribution of the Ca2+ signal throughout the process of egg activation might affect some epigenetic modifications that impact developmental processes.

Accumulation of the proteolytic marker peptide ubiquitin in the trophoblast of mammalian blastocysts

Ubiquitination is a universal protein degradation pathway in which the molecules of 8.5-kDa proteolytic peptide ubiquitin are covalently attached to the epsilon-amino group of the substrate's lysine residues. Little is known about the importance of this highly conserved mechanism for protein recycling in mammalian gametogenesis and fertilization. The data obtained by the students and faculty of the international training course Window to the Zygote 2000 demonstrate the accumulation of ubiquitin-cross-reactive structures in the trophoblast, but not in the inner cell mass of the expanding bovine and mouse blastocysts. This observation suggests that a major burst of ubiquitin-dependent proteolysis occurs in the trophoblast of mammalian peri-implantation embryos. This event may be important for the success of blastocyst hatching, differentiation of embryonic stem cells into soma and germ line, and/or implantation in both naturally conceived and reconstructed mammalian embryos.

Glucocorticoid receptor signaling in the intestinal epithelial cell lines IEC-6 and Caco-2: evidence of inhibition by interleukin-1beta

BACKGROUND AND AIMS

Glucocorticoids are potent anti-inflammatory drugs widely used in the treatment of inflammatory bowel disease, but many patients do not benefit from glucocorticoid therapy (glucocorticoid resistance) or need inappropriately high doses to retain remission (glucocorticoid dependency). Because of the role of intestinal epithelial cells in inflammatory bowel disease we examined glucocorticoid receptor signaling and the effect of interleukin-1beta as one of the main proinflammatory cytokines in the intestinal epithelial cell lines IEC-6 and Caco-2.

METHODS

Dexamethasone effects on transcriptional activation was measured by reporter gene assay using a construct containing glucocorticoid-responsive elements. The transrepressive effect was monitored by a nuclear factor (NF) kappaB inducible reporter construct. In addition in IEC-6 cells immuncytochemistry was used to monitor glucocorticoid receptor translocation.

RESULTS

Dexamethasone induced receptor-mediated reporter gene transcription and receptor translocation, while interleukin-1beta significantly inhibited dexamethasone effects. Dexamethasone inhibited interleukin-1beta induced, NF-kappaB driven gene transcription only in IEC-6 and not in Caco-2 cells. However, in Caco-2 cells glucocorticoid receptor overexpression resulted in a marked decrease in NF-kappaB activity even in absence of dexamethasone.

CONCLUSIONS

These studies demonstrate that glucocorticoid receptor driven gene regulation in intestinal epithelial cells may contribute to the anti-inflammatory effects of glucocorticoids in inflammatory bowel disease. Our data are consistent with the notion that interleukin-1beta produced during inflammatory response induces steroid resistance, which is a common clinical problem in treating patients with inflammatory bowel disease.

A novel and rapid prediction assay for the effectiveness of IL-6 receptor specific antisense oligonucleotides by proliferation inhibition of an interleukin-6 dependent cell line

Interleukin-6 (IL-6) belongs to a family of cytokines that use receptors consisting of a common signal-transducing chain (gp130). Baf/3 cells transfected with the human IL-6 receptor (IL-6R) and gp130 (Baf/3-gp130/IL-6R) can only grow in medium containing IL-6. We attempted to interrupt the signal transducing pathway of IL-6 with the help of antisense oligonucleotides (ASOs) designed against the IL-6R. We used 18 different kinds of antisense oligonucleotides of overlapping sequences around the translational start codon of the human IL-6R. Sense ASOs were used as a control. The proliferation of cells was analysed by H-thymidine incorporation. Cell surface expression of the IL-6R was assessed by FACS analysis. We identified three ASOs which strongly inhibited the proliferation of IL-6 dependent transfected Baf/3 cells. Flow cytometric studies on the suppression of surface expression of IL-6R by ASOs showed a similar pattern. These results should help to clarify the structural requirements of functionally effective ASOs in the inhibition of IL-6R.

Long-term impact on a closed household of pet cats of natural infection with feline coronavirus, feline leukaemia virus and feline immunodeficiency virus

A closed household of 26 cats in which feline coronavirus (FCoV), feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) were endemic was observed for 10 years. Each cat was seropositive for FCoV on at least one occasion and the infection was maintained by reinfection. After 10 years, three of six surviving cats were still seropositive. Only one cat, which was also infected with FIV, developed feline infectious peritonitis (FIP). Rising anti-FCoV antibody titres did not indicate that the cat would develop FIP. The FeLV infection was self-limiting because all seven of the initially viraemic cats died within five years and the remainder were immune. However, FeLV had the greatest impact on mortality. Nine cats were initially FIV-positive and six more cats became infected during the course of the study, without evidence of having been bitten. The FIV infection did not adversely affect the cats' life expectancy.

Molecular basis of variant pseudo-hurler polydystrophy (mucolipidosis IIIC)

Mucolipidosis IIIC, or variant pseudo-Hurler polydystrophy, is an autosomal recessive disease of lysosomal hydrolase trafficking. Unlike the related diseases, mucolipidosis II and IIIA, the enzyme affected in mucolipidosis IIIC (N-Acetylglucosamine-1-phosphotransferase [GlcNAc-phosphotransferase]) retains full transferase activity on synthetic substrates but lacks activity on lysosomal hydrolases. Bovine GlcNAc-phosphotransferase has recently been isolated as a multisubunit enzyme with the subunit structure alpha(2)beta(2)gamma(2). We cloned the cDNA for the human gamma-subunit and localized its gene to chromosome 16p. We also showed, in a large multiplex Druze family that exhibits this disorder, that MLIIIC also maps to this chromosomal region. Sequence analysis of the gamma-subunit cDNA in patients from 3 families identified a frameshift mutation, in codon 167 of the gamma subunit, that segregated with the disease, indicating MLIIIC results from mutations in the phosphotransferase gamma-subunit gene. This is to our knowledge the first description of the molecular basis for a human mucolipidosis and suggests that the gamma subunit functions in lysosomal hydrolase recognition.

Exon-intron organization of the human gp130 gene

The exon-intron organization and sequences of the exon-intron boundaries of the human gp130 transmembrane receptor gene have been determined using genomic DNAs as samples. The gp130 gene comprises 17 exons and 16 introns. The positions of the exon-intron boundaries show good correlation to the functional/homology regions of gp130. Exons 3-17 code for the gp130 protein, and each subdomain of the receptor is encoded by a set of exons. The coding potential of exons and the intron phasing of the human gp130 gene conform to the patterns observed previously for other cytokine receptor genes. This supports the notions that the gp130 gene evolved from the same ancestral gene that gave rise to other members of the cytokine receptor family.

Detection of feline parvovirus in dying pedigree kittens

Feline parvovirus (FPV) was detected in the intestinal tract contents of 13 pedigree kittens which were fading or died suddenly by the use of a new chromatographic test strip for canine parvovirus (CPV) and FPV. The test appeared to be sensitive and specific for the detection of FPV and was a useful diagnostic aid. In three cases in which virus was grown in cell culture, the isolates were characteristic of FPV and not CPV. Cats in the households in which the kittens were reared were regularly immunised with FPV vaccines. The most likely explanation for the occurrence of FPV-associated disease was exposure of the young kittens to large doses of virus contaminating the environment.

Structural Organization of the WD repeat protein-encoding gene HIRA in the DiGeorge syndrome critical region of human chromosome 22

The human gene HIRA lies within the smallest critical region for the DiGeorge syndrome (DGS), a haploinsufficiency developmental disorder associated with instertitial deletions in most patients in a juxtacentromeric region of chromosome 22. The HIRA protein sequence can be aligned over its entire length with Hir1 and Hir2, two yeast proteins with a regulatory function in chromatin assembly. The HIRA transcription unit was found to spread over approximately 100 kb of the DGS critical region. The human transcript is encoded from 25 exons between 59 and 861 bp in size. Domains of highest conservation with Hir1 and Hir2 are encoded from exons 1-11 and 13-25, respectively. The amino- and carboxy-terminal regions of homology are separated from each other by a domain unique to HIRA that is encoded from a single exon. Seven WD repeats are conserved between yeast and man in the amino-terminal region of the HIR proteins. Individual repeats were found to be encoded from one, two, or three exons of the HIRA gene. End sequences have been obtained for all 24 introns, opening the way to PCR amplification of the entire coding sequence starting from genomic DNA. Point mutations can also be sought in 16 of the 24 introns that are readily PCR-amplifiable.

A prospective risk analysis of contemporary thoracic surgery

OBJECTIVE

The results of surgical therapy can only be accurately judged if the patients' characteristics and their impact on the outcome are known. The purpose of this study was to identify the risk factors of contemporary thoracic surgery, which could serve as a basis for a risk-matched comparison of different surgical techniques.

METHODS

The data of 15 patients' undergoing thoracic surgery were prospectively documented. The outcome of the various operative procedures applied was statistically correlated with the access procedure, sex, age, body mass, dignity of underlying disease and six concomitant diseases.

RESULTS

Four patients died within 30 days of surgery (mortality: 2.6%). Morbidity comprising all complications (class I) and morbidity comprising only complications of consequence for postoperative therapy (class II) rose with the number of concomitant diseases (50%/0% with no concomitant disease, 89%/33% with more than three concomitant diseases). Univariate testing identified malignant disease (P = 0.002), male sex (P = 0.003), body mass index of less than 20 and more than 27 kg/m of the expected level according to the Quetelet rule (P = 0.013) and a combination of concomitant respiratory and cardiocirculatory disease (P = 0.022) as being associated with class I morbidity. Male sex was significantly coincident with class II morbidity (P = 0.020). Logistic regression analysis demonstrated that these characteristics also had independent influence on class I morbidity (P = 0.022, P = 0.001, P = 0.023, P = 0.028).

CONCLUSION

It is concluded that these characteristics are important predictors of morbidity of thoracic surgery. If a non-randomized comparison of the outcome of thoracic operations or different access strategies like thoracotomy or thoracoscopy is intended, at least these patient features should be documented and used as a basis for matching pairs.

Risk of feline infectious peritonitis in cats naturally infected with feline coronavirus

A longitudinal survey of 820 cats in 73 households was conducted over a period of 6 years to establish the fate of pet cats that were seropositive after natural exposure to feline coronavirus (FCoV). In particular, their risk of developing feline infectious peritonitis (FIP) was determined. The seropositive cats were assigned to 1 of 3 groups: cats from households in which FIP had recently been diagnosed; cats from households in which FIP had not been diagnosed, but from which kittens had been relocated and subsequently died of FIP; and cats from households in which FIP had not been diagnosed. Cats in the first group were not at greater risk of developing FIP than were cats in the other 2 groups. Consequently, any household in which seropositive cats live must be considered a potential source of FCoV that can cause FIP. There was no evidence that the enhanced disease, which has been described after experimentally induced infection of seropositive cats, exists in nature. Thus, analysis of the survival of the seropositive cats over periods of up to 36 months indicated that their risk of developing FIP decreased with time, suggesting the development of immunity rather than increased susceptibility to disease. In addition, of 56 cats deemed to have been naturally reinfected because their anti-FCoV antibody titers decreased and subsequently increased, only 3 developed FIP.

Thoracoscopic treatment of recurrent pneumothorax by pleurabrushing and argon beam coagulation

There is no consensus in treating relapsing pneumothorax and pleural effusion. Various types of treatment exist. While open chest surgery with mechanical pleurodesis or pleurectomy is effective, with a recurrence rate close to zero, for patients in poor conditions this treatment may be disadvantageous because of its invasiveness. Therefore minimally invasive techniques using antibiotics, fibrin glue, talcum, kaolin, blood and silver nitrate have been described. Several side effects accompany these agents, and the recurrence rate is between 5-39%. New video-assisted thoracoscopic techniques have enabled surgeons to combine the effectiveness of pleurectomy with minimal invasiveness. Results using these techniques are encouraging. As with open pleurectomy, bleeding complications have been reported, Further disadvantages have to be considered, such as the effect of destroying the parietal layer of the pleura, which may complicate subsequent operations in the thoracic cavity. A technique for avoiding this pleural injury, while maintaining the same efficiency as open pleural abrasion and coagulation is described below.

An aggressive philosophy in controlled ovarian stimulation cycles increases pregnancy rates

To assess the effect of timing of human chorionic gonadotrophin (HCG) administration in ovarian stimulation cycles, the serum oestradiol concentration and follicle profile were compared with the clinical pregnancy rate in 582 ovarian stimulation-intra-uterine insemination (OS-IUI) cycles and 3917 in-vitro fertilization-embryo transfer (IVF-ET) cycles. The pregnancy rates increased exponentially with increasing oestradiol in both OS-IUI and IVF-ET cycles (R2 = 0.720, P < 0.001) but then decreased in OS-IUI cycles when the oestradiol concentration exceeded 5000 pmol/l (R2 = 0.936, P < 0.004) at HCG administration. In OS-IUI cycles the percentages of cycles with three or more mature follicles (> or = 18 mm diameter) increased up to an oestradiol concentration of 5000 pmol/l then declined, mirroring the pregnancy rate (R2 = 0.900, P = 0.01). The exponential increase in pregnancy rate with increasing oestradiol concentration in IVF-ET cycles suggests that high oestradiol concentration does not have a deleterious effect on endometrial receptivity. The decrease in pregnancy rate in OS-IUI cycles when oestradiol concentration exceeded 5000 pmol/l reflected fewer mature follicles, resulting from premature administration of HCG to avoid severe ovarian hyperstimulation syndrome (OHSS). We recommend that HCG administration be delayed until multiple follicles have reached maturity, and reducing the risk of severe OHSS by converting high risk OS-IUI cycles to IVF-ET, or if funds or facilities are unavailable, transvaginally draining all but four or five mature follicles.

Conditional expression and oncogenicity of c-myc linked to a CD2 gene dominant control region

Over-expression of the c-myc gene is widely implicated in the genesis of lymphoid neoplasia, including tumours of the T-cell lineage. To study the effects of deregulated c-myc expression on T-cell development and oncogenesis, we sought to generate a transgenic mouse model in which c-myc expression was targeted specifically to the T-cell lineage. A plasmid construct containing a dominant control region (DCR) from the human CD2 locus linked 5' to the human c-myc gene was used to generate 2 lines of transgenic mice. Both strains developed thymic lymphoma at low frequency, but thymic development and peripheral T-cell numbers were otherwise apparently normal. Low tumour penetrance was consistent with the observed lack of stable CD2-myc transgene mRNA in tissues of healthy transgenic mice. In contrast, transgene RNA was detected in all malignant tumours as well as in early lymphomatous lesions. RNase protection analyses confirmed these findings and showed that the PI human c-myc promoter was active in all neoplastic tissues but not in the thymus or other tissues of healthy transgenic mice. Despite the low spontaneous tumour incidence, the presence of the transgene markedly and uniformly accelerated the onset of tumours after neonatal infection with Moloney murine leukaemia virus. All tumours were rearranged for T-cell receptor beta-chain genes and were of T-cell origin from their surface phenotype (Thy-1+, CD3+, CD4+/-, CD8+, sIg-). Virus-accelerated tumours contained clonal integrations of Moloney murine leukaemia virus, suggesting that proviral insertional mutagenesis may have played a role in tumour development. Analysis of several candidate myc-cooperating genes failed to reveal any rearrangements apart from a low frequency involving proviral insertion at the pim-1 locus. The CD2-myc mouse should therefore be a valuable system in screening for novel myc-collaborating genes involved in T-cell lymphoma.

Subtentorial subdural empyema: Case report

We present a case of an extensive subtentorial subdural empyema of otorhinological origin. Although 3%-6% of all intracranial suppurations are infratentorial, there is no report on extensive multiloculated subtentorial empyema so far.

Developmentally programmed induction of differentiation inhibiting activity and the control of stem cell populations

Differentiation inhibiting activity/leukemia inhibitory factor (DIA/LIF) is a glycoprotein that controls differentiation of pluripotential stem cells. Alternative transcription generates both diffusible and matrix-associated forms of DIA/LIF. Transcriptional analysis using a sensitive ribonuclease protection assay revealed that the two messages are expressed independently, consistent with the proposition that the two forms of DIA/LIF have distinct biological roles. DIA/LIF expression was found to be activated early during differentiation of embryonic stem (ES) cells, providing a mechanism for feedback regulation of stem cell renewal. Expression of DIA/LIF by mesenchymal cells was shown to be controlled in a paracrine manner by polypeptide regulatory factors. Specific expression of the two forms of DIA/LIF was also demonstrated in the egg cylinder-stage mouse embryo. The combination of cell type-specific and signal-specific regulation enables very precise control over DIA/LIF expression and may represent an important component of the regulatory networks that govern stem cell proliferation and differentiation during mammalian development.

Differentiation inhibiting activity is produced in matrix-associated and diffusible forms that are generated by alternate promoter usage

The differentiation of embryonic stem (ES) cells is controlled by the regulatory factor differentiation inhibiting activity/leukemia inhibitory factor (DIA/LIF). Examination of feeder cell-mediated suppression of ES cell differentiation revealed that DIA/LIF is produced both as a diffusible protein and in an immobilized form associated with the extracellular matrix. This alternative localization arises from the expression of alternate transcripts that diverge throughout exon 1. The effect of alternate first exon usage is to change the amino terminus of the primary translation product and to direct incorporation of mature, biologically active DIA/LIF into the extracellular matrix. The production of a potent regulatory factor in both diffusible and immobilized forms may be an important element of developmental control mechanisms.

The identification and management of drug-seeking behavior in a medical center

We describe the development of a quality assurance program that monitors prescription medication misuse in a medical setting. The program focuses on patient activities that influence physician prescribing of abusable medications. Seven defining criteria have been developed to judge the presence of drug seeking by patients. When appropriate, a drug-seeking label is attached to the patient's chart and the hospital computer information system. The warning informs the physician and protects the patient from excessive medications.

The rhythmic properties of the motor system

The resonance properties of the motor control circuits are basic features of the motor system. From our results, it can be concluded that, when the normally existing suppression mechanism weakens, external stimuli or internal impulses may elicit oscillations in the circuits according to the resonant frequency, and tremor will appear. It seems that the resonant frequency is between 5 and 8 Hz, as demonstrated by rhythmic voluntary movement, rhythmic elicited reflex movement and rhythmic modulated voluntary movement modulated by the stimulation of the central motor system.

Separation of the tumor and brain surface by "water jet" in cases of meningiomas

In the surgery of meningiomas one of the most delicate problems is the separation of the tumor from the brain surface. The authors generally recommend microsurgery to preserve the brain surface anatomically and functionally. For this purpose we have developed a new surgical technique according to our concepts of tissue care. After excavating the tumor from inside the tumor brain surface was separated by repeated "water jets" into the tumor arachnoideal space. The "water jet" was produced by an ordinary bulb syringe. The front pressure of the jets was 300-1000 mm of water and the side pressure 100-300 mm of water. In the tumor-arachnoideal space the spreading water (phys. NaCl) separates the brain from the tumor with utmost care. We operated on 55 meningiomas of different types with the "water jet" technique. The immediate results were anatomically excellent. Intraoperative and postoperative acute and late edemas appeared only in a few cases. The functions of the nearby brain were generally preserved. The surgery was uneventful when the tumor surface was smooth and the tumor was spherical. When the tumor surface was uneven, one part of the tumor extended under the dura as a thin layer or the tumor was multilobulated with expanded vessels between the lobules, more microseparation was necessary. We compared the results of the "water jet" technique with the results of the "pre-water jet" series. The surgery with the "water jet" technique was much shorter and its results were better than those of microsurgery alone.

Prevalence of positive epicutaneous tests among infants, children, and adolescents

We studied 314 otherwise healthy children younger than 18 years of age with epicutaneous testing, and found that 20% of those tested had at least one positive epicutaneous test result. Neomycin, nickel, and potassium dichromate were the most prevalent allergens detected in our study group. We found that sensitization occurred at less than 5 years of age for all but fragrance allergens. Aluminum chambers and the American Academy of Dermatology Patch Test Kit were found to be safe for use in infants, children, and adolescents.

Therapist's management of tendon transfers

Rehabilitation of the tendon transfer patient is a challenge to the hand therapist, given the variety of transfers performed and the level of skill, knowledge, and creativity needed to treat them adequately. Careful preoperative evaluation and treatment increase the prospects for a successful result. The postoperative care of the tendon transfer is a team effort by the surgeon, therapist, and patient; each must have a clear understanding of the goals and precautions of each stage of treatment. Restrictions are initially placed upon the patient's mobility to allow healing; these are then reduced as he activates the transfer and then begins to incorporate the new motion into daily activity. Resistance is added gradually to the patient's tolerance, and care is taken throughout the rehabilitation process not to overwork the muscle in its new function. Tendon transfer is never completely restorative, but often makes a striking difference in the patient's functional abilities. The outcome can be very gratifying for the patient and for those who collaborate in his treatment.

Interaction between feline leukaemia virus subgroups in the pathogenesis of erythroid hypoplasia

The interaction of feline leukaemia virus (FeLV) of subgroups A and C in the pathogenesis of erythroid hypoplasia in cats was studied. Weanling kittens infected with FeLV-A became permanently viraemic but remained haematologically normal over a period of 36 weeks. Similar kittens inoculated with FeLV-C, which produces erythroid hypoplasia when administered to newborn kittens, neither became viraemic nor developed the disease. However, weanling kittens inoculated with a mixture of FeLV-A and C became viraemic, first with FeLV-A and then additionally with FeLV-C, and the emergence of FeLV-C into the blood coincided with the advent of erythroid hypoplasia. When FeLV-C was inoculated into five older cats which had been viraemic with FeLV-A for several months previously, it appeared in the plasma of three of the cats and erythroid hypoplasia was diagnosed in two of these, 16-20 weeks after infection with FeLV-C. These results show that FeLV-A enhances the growth of FeLV-C in cats and overcomes their age-related resistance to FeLV-C. Also, the appearance of FeLV-C in the plasma of cats viraemic with FeLV-A indicates that erythroid hypoplasia will subsequently occur rapidly. These findings are relevant to the origin of FeLV-C isolates and their occurrence in nature.