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PubMed1997

Interactions between the ABI1 and the ectopically expressed ABI3 genes in controlling abscisic acid responses in Arabidopsis vegetative tissues.

In Arabidopsis, the abscisic acid (ABA)-Insensitive ABI1 and ABI3 genes have been proposed to act in separate ABA signalling cascades. Recessive mutations in ABI3 alter various physiological processes during seed development, whereas the dominant abi1 mutation inhibits ABA responses largely in vegetative tissues. The seed-specific ABI3 gene was ectopically expressed in the vegetative tissues of transgenic Arabidopsis plants carrying a transcriptional fusion between the CaMV 35S promoter and the ABI3 cDNA. Genetic interactions between the ectopically expressed ABI3 and endogenous ABI1 genes were investigated by monitoring diverse ABA responses in vegetative tissues. Ectopic expression of ABI3 conferred to plantlets the ability to accumulate the seed-specific At2S33 and AtEm1 mRNAs in response to ABA, and the abi1 mutation inhibited this ABI3-dependent induction of AtEm1 by ABA. Furthermore, ectopic expression of ABI3 also influenced ABI1-dependent responses that occur in wild-type vegetative tissues. Expression of ABI3 increased ABA induction of the Rab18 mRNA and ABA inhibition of root growth, and both responses were sensitive to the abi1 mutation in the presence as in the absence of ABI3. Finally, although ABI3 is thought to be a transcription activator and stomatal regulation is not known to involve transcriptional events, the ectopically expressed ABI3 gene suppressed the effect of the abi1 mutation on stomatal regulation. The present data demonstrate that ABI1 and ABI3 genetically interact in controlling diverse ABA responses in transgenic vegetative tissues. The possibility that the endogenous ABI1 and ABI3 genes may similarly act in a common ABA signalling pathway in seed is discussed with previous phenotypic studies of the abi1 and abi3 mutants.

Abscisic Acid↗

PubMed2001

Ectopic expression of ABI3 gene enhances freezing tolerance in response to abscisic acid and low temperature in Arabidopsis thaliana.

The plant hormone abscisic acid (ABA) regulates several physiological and developmental processes in plants, including stress adaptation and seed maturation. ABA-mediated processes appear to be central in plant cold acclimation and expression of cold acclimation-related genes. Ectopic expression of ABI3 encoding a seed-specific transcriptional activator confers on Arabidopsis vegetative tissues the ability to accumulate seed-specific transcripts in response to ABA, and also influences some ABA-mediated vegetative responses. In the present study we characterized the effect of ectopic expression of ABI3 on cold acclimation and development of freezing tolerance in Arabidopsis. We first determined the effect of ABI3 on ABA-induced expression of cold acclimation-related genes. Expression of ABI3 increased the ABA-induced accumulation of transcripts for several ABA/cold/drought-responsive genes such as RAB18 and LTI78. Enhanced expression of these genes was evident even after transient application of ABA, and the enhanced expression was correlated with increased freezing tolerance in ABI3 transgenic plants. Ectopic expression of ABI3 also appeared to modulate low temperature-induced freezing tolerance. The ABI3 transgenic plants acclimated faster than the wild-type plants, and the maximum tolerance obtained was significantly higher. These data showed that lower levels of ABA were needed to trigger the expression of the genes and to maintain the freezing-tolerant state in the ABI3 transgenic plants, and indicate that ectopic expression of ABI3 leads to enhanced responsiveness to ABA. The ectopic expression of ABI3 could provide a new strategy for engineering plant stress tolerance.

Abscisic Acid↗

PubMed2003

Ectopic activity in cutaneous regenerating afferent nerve fibers following nerve lesion in the rat.

Spontaneous activity, and mechanical and thermal sensitivity were investigated in regenerating afferent nerve fibers within 4-21 days post sural nerve lesion (crush or transection and resuturing) in anaesthetized rats. About 33-40% of the myelinated (A) and 22-27% of the unmyelinated (C) fibers excited by electrical nerve stimulation exhibited at least one of these ectopic discharge properties. In total 177 A- and 169 C-fibers with ectopic activity were analysed. Most A-fibers (161/177) were mechanosensitive. Spontaneous activity (median 1 imp/s) was present in 23/177 and thermosensitivity in 14/177 A-fibers (13 of them being activated by heat stimuli). Almost all A-fibers (159/177) exhibited only one type of ectopic discharge property. Most C-fibers (94/169) were thermosensitive responding either to cold (n = 45) or to heat stimuli (n = 33) or to both (n = 16). Eighty-four of 169 C-fibers were spontaneously active (median 0.3 imp/s) and 75/169 C-fibers were mechanosensitive. Both the proportion and the discharge rate of spontaneously active C-fibers were significantly higher after crush than after section and resuturing of the nerve. About 60% of the C-fibers (101/169) had only one ectopic discharge property and 40% two or three. In conclusion, regenerating cutaneous afferent A- and C-fibers may develop mechano- and/or thermosensitivity as well as spontaneous activity. We suggest that spontaneous and evoked ectopic activity in regenerating cutaneous afferents are a function of the intrinsic functional properties of these neurons and of the interaction between the regenerating nerve fibers and non-neural cells during Wallerian degeneration in the nerve distal to the nerve lesion.

Action Potentials↗

PubMed1992

Changes in tubal blood flow in evaluating ectopic pregnancy.

Ectopic pregnancy is not recognized in 5523% of all cases using state-of-the-art diagnostic procedures. In this study, blood flow in tubal arteries was measured using a transvaginal duplex Doppler ultrasonography system. A 3.5 MHz Doppler transducer coupled to a 5 MHz imaging transvaginal sector probe was used to depict flow characteristics in the tubal branch of the uterine artery. This was performed in 102 patients. There was a significant increase in the blood flow on the tubal gestation side (p < 0.0001; z = -4.08). This between-side difference was determined using qualitative frequency shift analysis. The mean reduction in the resistance index on the side with the ectopic pregnancy as compared to the contralateral side was 15.6%. These changes appear to be due to trophoblast invasion. Between-side differences showed no dependence on gestational age (between gestational weeks 4 and 12 postmenstruation). We compared these data with those from three control groups ('early viable intrauterine pregnancy', 'early intrauterine pregnancy failure', 'non-gravid state'). In all these control groups, the impedance to flow, expressed as 'resistance index', showed no significant between-side difference. All control groups had significantly higher mean resistance index values than the ectopic pregnancy side, but did not differ from the contralateral side of the ectopic pregnancy group. The advantages of this new method in diagnosing ectopic pregnancy are early detection, non-invasivity, and immediate results.

Journal Article↗

PubMed1993

Ectopic pregnancy: transvaginal sonographic findings of 152 cases.

In a retrospective study performed on 152 cases of verified ectopic pregnancy, the features at transvaginal sonography were evaluated. A total of 146 (96%) of the patients had at least one abnormal sonographic feature and pelvic/cul-de-sac fluid was the most common finding, detected in all of the 146 patients. Pelvic/cul-de-sac fluid was particulate in 103 patients and simple in 43. Pelvic/cul-de-sac fluid together with extrauterine findings were found to be present in 93.8% (137/146) of the patients, suggesting the fact that if pelvic/cul-de-sac fluid was detected, every effort should be made to image the tube. The extrauterine transvaginal sonographic features included 102 (63.0%) patients with a mass, 60 (41.1%) with a gestational sac (with or without yolk sac or embryo), and eight (5.3%) with a living embryo. Comparison of the sonographic findings according to the status of the ectopic pregnancy revealed that particulate fluid (98.9%), and an extra-uterine mass (88.2%) were the features that aided in the diagnosis of ruptured and aborted ectopic pregnancies, whereas an extrauterine gestational sac (72.9%), and a living embryo (11.9%) were associated with intact ectopic pregnancies. Our findings support the practice of using transvaginal sonography, and ss-human chorionic gonadotropin measurements in the diagnosis and prediction of the status of ectopic pregnancy.

Journal Article↗

PubMed2001

Electrocardiographic analysis of ectopic atrial activity obscured by ventricular repolarization: P wave isolation using an automatic 62-lead QRST subtraction algorithm.

INTRODUCTION: Atrial activity on the surface ECG during premature beats and supraventricular arrhythmias frequently is obscured by the superimposed QRST complex of the previous cardiac cycle. This study examines the performance of a newly developed automatic QRST subtraction algorithm to isolate ectopic P waves from the preceding T-U wave. METHODS AND RESULTS: The 62-lead ECG recordings were obtained during (1) sinus rhythm and programmed right atrial stimulation in 12 patients (group A); and (2) sinus rhythm and atrial premature beats, atrial tachycardia, or paroxysmal atrial fibrillation in 5 patients (group B). Pacing in group A patients was conducted at a slow drive cycle length to generate an ectopic P wave not obscured by the previous QRST complex and by delivering single premature extrastimuli at progressively shorter coupling intervals to produce an ectopic P wave obscured by the upsloping (early T-U wave), peak (middle T-U wave), and downsloping component of the T-U wave (late T-U wave). All ectopic P waves in group B patients were concealed by the preceding T-U wave. Automatic QRST subtraction was attained using an adaptive template constructed from averaged QRST complexes (mean 83 +/- 25 complexes) obtained during sinus rhythm (groups A and B) or atrial overdrive pacing (group A). P wave integral maps subsequently were computed, visually compared, and mathematically correlated. A high correspondence in spatial map pattern was observed between integral maps of "nonobscured" and previously "obscured" paced P waves obtained in group A patients (mean r = 0.88 +/- 0.07) as well as between integral maps of two to three previously obscured P waves with the same atrial arrhythmia morphology obtained in group B patients (mean r = 0.94 +/- 0.05). Improved morphologic P wave replication in group A patients was acquired when concealment occurred in the early (mean r = 0.90 +/- 0.08) or late part of the T-U wave (mean r = 0.90 +/- 0.06) as opposed to the middle T-U wave (mean r = 0.85 +/- 0.07) (P = NS and P < 0.05 for early vs middle and late vs middle T-U wave, respectively). CONCLUSION: This novel automatic 62-lead QRST subtraction algorithm enables discrete isolation of T-U wave obscured ectopic atrial activity on the surface ECG while retaining the intricate spatial detail in P wave morphology. Future clinical application of the algorithm may enable improved ECG localization of focal triggers of paroxysmal atrial fibrillation, atrial tachycardia, and the atrial insertion of accessory pathways.

Adult↗

PubMedDate not supplied

Massive bleeding from an ectopic lingual thyroid follicular adenoma during pregnancy.

Ectopic thyroid is a rare developmental anomaly. It can be found anywhere between the foramen cecum and the normal position of the thyroid gland. Massive bleeding from an ectopic lingual thyroid is unusual and occasionally fatal. We present a case of a 22-year-old woman who had a large mass at the base of the tongue for over 6 years. In the sixth month of pregnancy, the patient experienced massive bleeding from the tongue base mass. A thyroid scan revealed that this mass was the only functioning thyroid tissue. Because of massive bleeding and her shock status, the patient received an emergent embolization of the bilateral lingual arteries. Then the huge lingual thyroid was subsequently excised via a mandible swing approach to prevent further episodes of bleeding. Pathology analysis indicated ectopic thyroid tissue with follicular adenoma. She delivered without complications in the 36th week and had a normal baby. This case was a very rare one in our review. Although ectopic lingual thyroid usually is not managed surgically, excision of ectopic lingual thyroid can be life-saving when it is causing bleeding or airway obstruction.

Adenoma↗

PubMed2006

Salvage of amputated upper extremities with temporary ectopic implantation followed by replantation at a second stage.

Salvage of the complex amputation of extremities, such as combined with devastating segmental injuries, extensive soft tissue defect, and multiple important organ injuries, continues to be a challenge for plastic surgeons. Temporary ectopic implantation of the amputated part to a healthy recipient site allows the patient to recover from critical combined injuries, radical debridements, and soft tissue repair. In this article, the authors report two cases of temporary ectopic implantation of complexly amputated forearms, followed by successful replantation to their anatomic positions at a second stage. The contralateral upper extremity is an acceptable recipient site for temporary ectopic implantation. In secondary replantation, a cross-arm flap can be designed to carry the vascular pedicle from the ectopic implantation recipient to improve blood supply to the replanted part when the second blood supply is established. The authors validated that temporary ectopic implantation of amputated parts provides an alternative procedure for the salvage of amputated extremities under special circumstances.

Adult↗

PubMed2002

Hemorrhagic shock from a ruptured ectopic pregnancy in a patient with a negative urine pregnancy test result.

Ectopic pregnancy has been increasing in frequency over the past 2 decades. The sudden rupture of a fallopian tube caused by ectopic pregnancy can lead to hemorrhagic shock and death if not diagnosed and treated in a timely fashion. The emergency physician is often the health professional that is called on to make the diagnosis and coordinate timely and effective intervention. The first step in the diagnosis of ectopic pregnancy is demonstration of pregnancy by means of a rapidly performed and sensitive qualitative urine test for the beta-subunit of human chorionic gonadotropin (beta-hCG). A negative urine pregnancy test result will generally be used to exclude ectopic pregnancy from further consideration. The following is a report of a patient presenting to an emergency department with hypovolemic shock in conjunction with 2 negative urine beta-hCG analysis results and a quantitative serum beta-hCG level of 7 mIU/mL, a value less than the lower limit of detection for the highly sensitive qualitative urine and serum tests. This case report demonstrates the importance of further consideration of the diagnosis of ectopic pregnancy in the setting of a negative urine pregnancy test result.

Adult↗

PubMed2002

The RecA intein of Mycobacterium tuberculosis promotes cleavage of ectopic DNA sites. Implications for the dispersal of inteins in natural populations.

The RecA intein of Mycobacterium tuberculosis, a novel double-stranded DNA endonuclease, requires both Mn(2+) and ATP for efficient cleavage of the inteinless recA allele. In this study, we show that Mg(2+) alone was sufficient to stimulate PI-MtuI to cleave double-stranded DNA at ectopic sites. In the absence of Mg(2+), PI-MtuI formed complexes with topologically different forms of DNA containing ectopic recognition sequences with equal affinity but failed to cleave DNA. We observed that PI-MtuI was able to inflict double-strand breaks robustly within the ectopic recognition sequence to generate either a blunt end or 1-2-nucleotide 3'-hydroxyl overhangs. Mutational analyses of the presumptive metal ion-binding ligands (Asp(122), Asp(222), and Glu(220)) together with immunoprecipitation assays provided compelling evidence to link both the Mg(2+)- and Mn(2+) and ATP-dependent endonuclease activities to PI-MtuI. The kinetic mechanism of PI-MtuI promoted cleavage of ectopic DNA sites proceeded through a sequential mechanism with transient accumulation of nicked circular duplex DNA as an intermediate. Together, these data suggest that PI-MtuI, like group II introns, might mediate ectopic DNA transposition and hence its lateral transfer in natural populations.

Adenosine Triphosphate↗

PubMed2000

Current trends in management of ectopic pregnancy in the United Kingdom.

The potential advantages of laparoscopic management of ectopic pregnancy include lower morbidity, faster return to work, and less impact on reproductive health. This study aimed to investigate the current management of ectopic pregnancy in the United Kingdom. Thirty-five per cent of ectopic pregnancies are currently managed laparoscopically. Units that tended to operate laparoscopically were more likely to attempt to preserve the fallopian tube at surgery. Ninety per cent of units in the UK feel that they potentially could manage ectopic pregnancies laparoscopically but in practice only 60% managed any of the last three ectopic pregnancies by this technique.

Journal Article↗

PubMed1998

An analysis of ectopic pregnancies following in vitro fertilisation treatment in a 10-year period.

Of clinical pregnancies in our in vitro fertilisation (IVF) programme, 5.4% were ectopic and 0.85% of clinical pregnancies (15% of ectopic pregnancies) were heterotopic. Ectopic pregnancies were more common after IVF/embryotransfer (ET) than frozen embryotransfer (FET). Although there was a suggestion that tubal factors were more common in those with ectopic pregnancies, the difference did not reach statistical significance. No relationship existed with regard to the ovarian stimulation regimen, the dosage/ duration of human menopausal gonadotrophin used, the details of embryo transfer and number of embryos transferred. Patients who develop ectopic pregnancies after IVF can be counselled that they have a good chance of achieving a normal pregnancy with subsequent attempts.

Journal Article↗

PubMed1999

Ectopic pregnancy - laparoscopic management in a district general hospital.

A 2-year retrospective study was carried out in a district general hospital to review the outcome of laparoscopic management versus laparotomy for the management of ectopic pregnancy. Outcome measures included operating time, postoperative analgesia requirements, complications, length of hospital stay, the post-ectopic intrauterine pregnancy rates and the recurrent ectopic pregnancy rates over an observational period of 16 months. Forty-nine consecutive women were seen. Twenty-six were managed laparoscopically and 23 were managed by laparotomy. There was no significant difference between the operating times and complications but the laparoscopy group had significantly fewer doses of opiate analgesia (P<0.05), shorter length of stay (P<0.05), and significantly higher post-ectopic intrauterine pregnancy rates (P<0.05) compared with the laparotomy group. Laparoscopic management of ectopic pregnancy is a viable alternative to conventional laparotomy in district general hospitals.

Journal Article↗

PubMed1999

Difference in mRNA expression and occurrence of plasminogen activator inhibitors in intrauterine decidua of normal and ectopic human pregnancies.

The objective of this study was to elucidate the mechanisms involved in the formation of a functional decidua. The concentrations of plasminogen activators and plasminogen activator inhibitors in intrauterine decidua from normal and ectopic pregnancies were compared. Intrauterine decidua was obtained by curettage from 17 women with ectopic pregnancies and from five women with normal pregnancies. The gestational age was similar in the two groups. The antigen concentrations of plasminogen activators and plasminogen activator inhibitors in decidua homogenate were determined by ELISA and fibrinolytic activity was measured on fibrin plates. Localization was determined by immunohistochemical staining and mRNA was identified by in situ hybridization. Fibrinolytic activity was absent in decidua from normal pregnancies but present in the intrauterine decidua from ectopic pregnancies. High antigen concentrations of the inhibitors of fibrinolysis, PAI-1 and PAI-2, were found in normal decidua in contrast to low concentrations in decidua from ectopic pregnancies. Staining for PAI-1 as well as PAI-2 was positive in decidual cells. In situ hybridization resulted in high intensity signals for PAI-1 as well as for PAI-2 mRNA in decidua from normal pregnancies in contrast to very low intensity signals in decidua from ectopic pregnancies. The absence of proteolytic activity and high expression of PAI-1 and PAI-2 in normal decidua might facilitate attachment of the fertilized ovum and might also prevent detachment of the decidua.

Journal Article↗

PubMedDate not supplied

Repair of osteochondral defects in rabbits with ectopically produced cartilage.

Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal cartilage defects. Ectopic cartilage was produced by dissecting a piece of periosteum from the tibia of rabbits. After 14 days the reactive tissue at the dissection site was harvested and a graft was cored out and press-fit implanted in an osteochondral defect in the medial condyle of the femur with or without addition of hyaluronan. After 3 weeks and 3 months the repair reaction was evaluated by histology. Thionine- and collagen type II-stained sections were evaluated for graft viability, ingrowth of the graft, and joint surface repair. Empty defects remained empty 3 weeks after implantation, ectopic cartilage filled the defect to the level of the surrounding cartilage. Histologically, the grafts were viable, consisting mainly of cartilage, and showed a variable pattern of ingrowth. Three months after implantation empty defects with or without hyaluronan were filled primarily with fibrocartilaginous tissue. Defects treated with ectopic cartilage contained mixtures of fibrocartilaginous and hyaline cartilage. Sometimes a tidemark was observed in the new articular cartilage and the orientation of the cells resembled that of healthy articular cartilage. Subchondral bone repair was excellent. The modified O'Driscoll scores for empty defects without and with hyaluronan were 12.7 +/- 6.4 and 15.3 +/- 3.2; for treated defects scores were better (15.4 +/- 3.9 and 18.2 +/- 2.9). In this conceptual study the use of ectopic cartilage derived from periosteum appears to be a promising novel method for joint surface repair in rabbits.

Animals↗

PubMed1999

Graves' disease and recurrent ectopic thyroid tissue.

Ectopic thyroid tissue is the result of abnormal migration of the gland as it travels from the floor of the primitive foregut to its destined pretracheal position. The prevalence of ectopic thyroid tissue ranges between 7%-10%. Patients with ectopic thyroid tissue are usually euthyroid, but can present with signs and symptoms of upper aerodigestive tract obstruction. We report a case in which ectopic mediastinal thyroid tissue was removed surgically because of substernal chest pain. It recurred 9 years later when the patient developed Graves' disease. We propose that the recurrence of the ectopic thyroid tissue was due to the influence of thyroid stimulating immunoglobulins (TSI).

Choristoma↗

PubMed1984

Ventricular ectopic activity and its relevance to aircrew licensing.

Ventricular ectopic complex ( VEC ) activity is seen frequently, both in patients with cardiovascular disease and in normal subjects. It has been claimed to be predictive of cardiovascular disease but in the asymptomatic individual it may be benign. Unifocal ventricular ectopic complexes with activity greater than 2 per 100 on the resting electrocardiogram of an applicant for a flying licence should be assessed. Further investigation including exercise electrocardiography and tape monitoring may be indicated. Even following investigation, empirically high counts may be acceptable only for multi-crew operation. Complex ventricular ectopic activity including multiformity, pairs, ventricular tachycardia, R-on-T ectopic beats, bigeminy and trigeminy, and parasystole, are incompatible with unrestricted certification and most are incompatible with any form of certification as individual risk-stratification is not yet possible. Of these, bigeminal arrhythmias are, however, likely to be the most benign, while R-on-T ectopic complexes and ventricular tachycardia are the most malignant.

Adult↗

PubMed1991

Allelic and ectopic interactions in recombination-defective yeast strains.

Ectopic recombination in the yeast Saccharomyces cerevisiae has been investigated by examining the effects of mutations known to alter allelic recombination frequencies. A haploid yeast strain disomic for chromosome III was constructed in which allelic recombination can be monitored using leu2 heteroalleles on chromosome III and ectopic recombination can be monitored using ura3 heteroalleles on chromosomes V and II. This strain contains the spo13-1 mutation which permits haploid strains to successfully complete meiosis and which rescues many recombination-defective mutants from the associated meiotic lethality. Mutations in the genes RAD50, SPO11 and HOP1 were introduced individually into this disomic strain using transformation procedures. Mitotic and meiotic comparisons of each mutant strain with the wild-type parental strain has shown that the mutation in question has comparable effects on ectopic and allelic recombination. Similar results have been obtained using diploid strains constructed by mating MATa and MAT alpha haploid derivatives of each of the disomic strains. These data demonstrate that ectopic and allelic recombination are affected by the same gene products and suggest that the two types of recombination are mechanistically similar. In addition, the comparison of disomic and diploid strains indicates that the presence of a chromosome pairing partner during meiosis does not affect the frequency of ectopic recombination events involving nonhomologous chromosomes.

Alleles↗