bluuebunny/crossref_metadata_2025 huggingface dataset:
Scanning electron microscopy description of a new species of Demodex canis spp.
Authors: Tamura Yukio , Kawamura Yoko , Inoue Isamu , Ishino Seishi
Published: March 2003

Between 1997 and 1999, the prevalence of Demodex canis mites was determined in 150 dogs. In two dogs, we found two different species of mites; Demodex canis and another, unidentified, Demodex mite. The unidentified Demodex mite species had several different morphological features. First, it had a short opisthosoma and an obtuse end. In addition, the fourth coxisternal plate was rectangular and there was a band‐like segmental plate between the fourth coxisternal plate and opisthosoma. Although all of the morphology and the development of male mites could not be investigated in this study, the location of the opisthosoma and the genital pore clearly differed from Demodex canis, suggesting that this unidentified mite is a new species.
A method for isolating a high yield of Arabidopsis chloroplasts capable of efficient import of precursor proteins
Authors: Fitzpatrick Lynda M. , Keegstra Kenneth
Published: March 2003

Chloroplasts were isolated from Arabidopsis plants grown under different conditions, and using different protocols, to determine a method that would yield chloroplasts capable of binding and importing precursor proteins. Chloroplasts isolated from protoplasts and purified on a Percoll gradient were highly import‐competent, with little non‐specific binding of the precursor, and a high yield of intact chloroplasts (0.1 mg chlorophyll/g FW). Chloroplasts from plants grown on agar plates had a much higher rate of import than those from plants grown on soil. Protein import remained high at all of the ages tested for chloroplasts from plate‐grown plants, whereas it declined during the development of soil‐grown plants. Arabidopsis chloroplasts imported a range of precursor proteins and had nucleotide requirements for binding and import similar to those reported for pea chloroplasts.
Divalent cations and polyamines bind to loop 8 of 14‐3‐3 proteins, modulating their interaction with phosphorylated nitrate reductase
Authors: Athwal Gurdeep S. , Huber Steven C.
Published: March 2003

Binding of 14‐3‐3 proteins to nitrate reductase phosphorylated on Ser543 (phospho‐NR) inhibits activity and is responsible for the inactivation of nitrate reduction that occurs in darkened leaves. The 14‐3‐3‐dependent inactivation of phospho‐NR is known to require millimolar concentrations of a divalent cation such as Mg2+ at pH 7.5. We now report that micromolar concentrations of the polyamines, spermidine4+ and spermine3+, can substitute for divalent cations in modulating 14‐3‐3 action. Effectiveness of the polyamines decreased with a decrease of polycation charge: spermine4+ > spermidine3+ >>> cadavarine2+ ≈ putrescine2+ ≈ agmatine2+ ≈ N1‐acetylspermidine2+, indicating that two primary and at least one secondary amine group were required. C‐terminal truncations of GF14ω, which encodes the Arabidopsis 14‐3‐3 isoform ω, indicated that loop 8 (residues 208–219) is the likely cation‐binding site. Directed mutagenesis of loop 8, which contains the EF hand‐like region identified in earlier studies, was performed to test the role of specific amino acid residues in cation binding. The E208A mutant resulted in a largely divalent cation‐independent inhibition of phospho‐NR activity, whereas the D219A mutant was fully Mg2+‐dependent but had decreased affinity for the cation. Mutations and C‐terminal truncations that affected the Mg2+ dependence of phospho‐NR inactivation had similar effects on polyamine dependence. The results implicate loop 8 as the site of divalent cation and polyamine binding, and suggest that activation of 14‐3‐3s occurs, at least in part, by neutralization of negative charges associated with acidic residues in the loop. We propose that binding of polyamines to 14‐3‐3s could be involved in their regulation of plant growth and development.
A novel extinction screen in Arabidopsis thaliana identifies mutant plants defective in early microsporangial development
Authors: Sorensen A. , Guerineau F. , Canales‐Holzeis C. , Dickinson H. G. , Scott R. J.
Published: March 2003

Few Arabidopsis mutants defective in early male or female germline development have been reported. A novel extinction screen has been devised which permits the identification of mutants deficient in the earliest stages of anther development. Using mutagenized plants carrying GUS reporter constructs driven by tapetal‐specific promoters originally derived from Brassica genes, a wide spectrum of mutants have been identified in Arabidopsis, ranging from those defective in archesporial cell differentiation to others expressed later in development. Crosses between these lines and known anther development mutants have enabled the identification of lines carrying mutations in genes expressed during very early anther formation. Initial characterization reveals these early mutants fall into two classes, gne (GUS‐negative) 1‐like, and gne2‐like. Members of the gne1 mutant class initiate all four layers of the anther wall and an appropriate number of sporogenous cells; however, as development proceeds the tapetal and middle‐layer cells enlarge, eventually crushing the sporogenous cells. The gne2 class anthers are disrupted at an earlier stage, with the middle and tapetal layers failing to form, and an excess of sporogenous cells developing until the germline aborts late in meiosis II. Analysis of these mutants has already raised questions about the accuracy of current models of angiosperm anther development.
Direct delivery of bacterial avirulence proteins into resistant Arabidopsis protoplasts leads to hypersensitive cell death
Authors: Wu Yan , Wood Michelle D. , Tao Yi , Katagiri Fumiaki
Published: March 2003

Many bacterial avirulence (Avr) proteins, including the Pseudomonas syringae proteins, AvrRpt2 and AvrB, appear to be recognized inside the host plant cell by resistance mechanisms mediated by the cognate resistance (R) genes. It is thought that Avr proteins are either delivered directly into the host cell via the bacterial type III secretion system (TTSS) or taken up by the plant cell following secretion into the apoplast through the TTSS. Recently, it was shown that the Xanthomonas campestris AvrBs2 protein can be delivered directly into the host plant cell by the TTSS. However, it is not known whether other type III effectors of phytopathogens behave similarly. Here, using a novel protein transfection method, we demonstrate that AvrRpt2 and AvrB must enter the plant cell to be recognized by R gene‐mediated mechanisms. First, we established a hypersensitive cell death assay for protoplasts using the membrane‐impermeable, nuclear‐staining dye, YO‐PRO‐1, and transgenic Arabidopsis plants that carry an inducible avrRpt2 gene. Second, we transfected E. coli‐produced AvrRpt2 or AvrB proteins into Arabidopsis protoplasts using a protein transfection kit based on the carrier peptide Pep‐1, and demonstrated that hypersensitive cell death occurs in a gene‐for‐gene‐specific manner. In contrast, these Avr proteins failed to elicit hypersensitive cell death when they were applied to protoplasts without the carrier peptide. We conclude that our preparations of E. coli‐produced AvrRpt2 and AvrB are active, that AvrRpt2 and AvrB must be delivered into the plant cell to be recognized, and that a method based on a carrier peptide can be used to introduce proteins into plant cells.
A treatment decision‐making model for infraoccluded primary molars
Authors: Ekim S. L. , Hatibovic‐Kofman S.
Published: March 2003

The objective of this paper is to clarify the literature’s findings and provide guidelines for decision‐making during the long‐term treatment planning of infraoccluded primary molars. This paper presents a synopsis of findings concerning prevalence, aetiology, diagnostic methods, diagnostic criteria and treatment options. Treatment decisions are mainly guided by the clinical assessment of the presence or absence of succedaneous tooth, evaluation of onset, time of diagnosis, resorption rate, rate of progression of infraocclusion, risk of adverse effects over time, and predictive clinical patterns of infraoccluded primary molars. These models are a result of a comprehensive review of the literature and presents a compilation of findings in a format that is of practical use to the clinician.
Oral health in liver transplant children administered cyclosporin A or tacrolimus
Authors: Wondimu B. , Németh A. , Modéer T.
Published: March 2003

Background.

Immunosuppression by cyclosporin A (CsA) is associated with adverse side‐effects, including nephrotoxicity, neurotoxicity and gingival overgrowth. Tacrolimus (TAC/FK506) is a new immunosuppressive agent, recently approved for use in solid‐organ transplants. The mode of action of TAC is similar to that of CsA and the toxicity profile of CsA is duplicated by TAC. The effect of TAC on the gingival tissue is not yet conclusive.

Sample.

Gingival overgrowth was assessed in 30 liver transplant children, 20 boys and 10 girls, aged 2–19 years. Seventeen children (10 boys, seven girls) were on a CsA‐based immunosuppressive regimen whereas 13 children (10 boys, three girls) were on TAC for at least 1 year (mean 4·3 ± 2·7).

Results.

In the CsA group, 35% of children exhibited gingival overgrowth characterized by one or more units with increased sulcus probing depth (≥ 4 mm), i.e. pseudopockets. In contrast to the CsA group, none of the children in the TAC group exhibited gingival overgrowth. The occurrence of enamel hypoplasia was observed in 11 children (36%) and enamel opacities were found in 23 children (76%). Six of the 12 children (50%) with hyperbilirubinaemia biliary atresia exhibited a marked greenish discoloration of the teeth. Caries experience (dmft/DMFT) among these children was 2·0 ± 2·8.

Conclusion.

No difference in caries experience or enamel defect was observed between the CsA and TAC group.
Schinzel–Giedion syndrome: interesting facial and orodental features, and dental management
Authors: Cooke M. E. , Davidson L. E. , Livesey S. L.
Published: March 2003

Summary. Schinzel–Giedion syndrome comprises multiple congenital anomalies. The orofacial features include coarse facies, frontal bossing, ocular hypertelorism, anterior open bite and macrodontia. Two cases are presented in which the presence of specific craniofacial anomalies with bilateral hydronephrosis confirmed the diagnosis. In one patient, bottle‐feeding was associated with caries in maxillary central and lateral incisors, but the second patient was permanently tube fed and did not experience any dental caries. Clinical management of these patients requires a coordinated approach from a team of medical and dental specialists.
A new and simple Doppler method for measurement of fetal cardiac isovolumetric contraction time
Authors: Koga T. , Athayde N. , Trudinger B. , Nakano H.
Published: March 2003

Objectives

The fetal cardiac isovolumetric contraction time is defined as the interval between mitral valve closure and aortic valve opening. The objective of this study was to develop a simple and reliable Doppler method for measuring fetal isovolumetric contraction time using a digital filtering and processing system.

Methods

Cardiac Doppler signals were recorded from 40 fetuses at 18–40 weeks' gestation using a continuous‐wave ultrasound transducer. The raw signal was digitized, filtered and divided into five different frequency ranges: 250–375, 375–500, 500–750, 750–1000 and 1000–1500 Hz. To determine the most suitable filter setting for detecting mitral valve closure and aortic valve opening signals, we examined whether they were detected clearly in each filter range.

Results

Both mitral valve closure and aortic valve opening signals were detected clearly in the 500–1000 Hz range. The atrioventricular flow and outflow noises in the 250–500 and 1000–1500 Hz ranges helped us to identify the signals. It was found that dividing the raw signals into three ranges of 250–500, 500–1000 and 1000–1500 Hz was the most suitable digital‐filter setting for measuring isovolumetric contraction time.

Conclusions

We have developed a simple Doppler method for measuring fetal isovolumetric contraction time. The advent of digital processing has simplified the equipment and the simultaneous multidisplay of three different filtered signals enables easy and accurate measurement. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Serial sonographic findings of four fetuses with homozygous alpha‐thalassemia‐1 from 21 weeks onwards
Authors: Leung W. C. , Oepkes D. , Seaward G. , Ryan G.
Published: March 2003

Objectives

To evaluate the potential usefulness of noninvasive ultrasound assessment of fetal anemia in the diagnosis and management of fetuses with homozygous alpha‐thalassemia‐1.

Methods

We describe four pregnancies complicated by fetal homozygous alpha‐thalassemia‐1. They presented with ultrasound abnormalities before the development of hydrops. As part of evaluating the fetal condition, we performed ultrasound and Doppler studies aimed at identifying fetal anemia. These studies included evaluation of intrahepatic umbilical venous maximum flow velocity, middle cerebral artery peak flow velocity, fetal liver length and spleen perimeter.

Results

In all four fetuses, ultrasound and Doppler studies suggested the presence of fetal anemia. Homozygous alpha‐thalassemia‐1 was diagnosed in all cases, with fetal blood sampling confirming anemia in three fetuses. The majority of the intrahepatic umbilical venous maximum flow velocity and middle cerebral artery peak flow velocity measurements were above the 95th centile. Two fetuses underwent intrauterine transfusion and fetal blood flow velocities returned to normal after correction of the fetal anemia. The fetal liver length and spleen perimeter measurements showed a similar trend, although they were less consistent before 28 weeks.

Conclusion

Non‐invasive ultrasound parameters, in particular quantification of intrahepatic umbilical venous maximum flow velocity and middle cerebral artery peak flow velocity, were found to be useful in the diagnosis and management of fetal anemia in pregnancies with fetal homozygous alpha‐thalassemia‐1. Copyright © 2002 ISUOG
A case of prenatally diagnosed fetal neurenteric cyst
Authors: Uludağ S. , Madazli R. , Erdoğan E. , Dervişoğlu S. , Çelik E. , Ocak V.
Published: March 2003

The combination of a thoracic cystic mass with vertebral anomalies on prenatal ultrasound suggests a neurenteric cyst. The outcome of such cysts mostly depends on the extent of the displacement and functional impairment of the adjacent organs and of the associated central nervous system defects. We present a case of a neurenteric cyst diagnosed on prenatal ultrasound at 34 weeks of gestation which was treated successfully in the early neonatal period. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
First‐trimester sonographic umbilical cord diameter and the growth of the human embryo
Authors: Ghezzi F. , Raio L. , Di Naro E. , Franchi M. , Brühwiler H. , D'Addario V. , Schneider H.
Published: March 2003

Objectives

Experimental and clinical evidence have shown that the morphometry of the umbilical cord in the second half of gestation might be useful in predicting adverse perinatal outcome. The purposes of this study were to generate a nomogram for the umbilical cord diameter in the first trimester and, in an observational study, to investigate whether the sonographic measurement of the umbilical cord diameter early in gestation has the same clinical value as that late in gestation.

Methods

The sonographic umbilical cord diameter, crown–rump length and biparietal diameter were measured in 439 fetuses at between 8 and 15 weeks of gestation. The perinatal outcome was recorded for all patients.

Results

The umbilical cord diameter increased steadily from 8 to 15 weeks of gestation. A significant correlation was found between umbilical cord diameter and gestational age (r = 0.78; P < 0.001), umbilical cord diameter and crown–rump length (r = 0.75; P < 0.001) and umbilical cord diameter and biparietal diameter (r = 0.81; P < 0.001). No correlation was found between umbilical cord diameter values and either birth weight or placental weight. Among patients who had a miscarriage (n = 7) and pre‐eclampsia (n = 8) the umbilical cord diameter was below 2 standard deviations from the mean in three cases (42.9%) and three cases (37.5%), respectively.

Conclusion

The measurement of the umbilical cord diameter in the first trimester is correlated with the growth of the embryo and may be a marker for identifying a subset of fetuses at risk of spontaneous miscarriage and pre‐eclampsia. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
The accuracy of antenatal ultrasound in the detection of facial clefts in a low‐risk screening population
Authors: Cash C. , Set P. , Coleman N.
Published: March 2003

Objectives

To evaluate the accuracy of prenatal ultrasound in the detection of facial clefts in a low‐risk screening population and to report on the outcome of these pregnancies.

Design

We retrospectively reviewed antenatal ultrasound records from the obstetric ultrasound department, postnatal records from the regional craniofacial unit and autopsy reports of fetuses over 16 weeks' gestational age from the regional pathology department over a 5‐year period (1993–97). Cross‐referencing between the three data sets identified all cases of facial clefts.

Results

Out of 23 577 live and still births, 30 had facial clefts; four were excluded from the study. Of the remaining 26 cases, 10 had associated major anomalies. There were 19 live births and seven terminations. Six of the seven terminations had other major abnormalities. Our detection rate for cleft lip and palate was 93% and the detection rate for isolated cleft palate was 22%. Isolated cleft lip was detected in 67% of cases. The overall detection rate for facial clefts was 65%.

Conclusion

From our results and a review of the literature it is clear that before standards can be set we need to define which facial clefts are sonographically demonstrable. Our data provide information for effective counseling and setting of standards for clinical practice. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Prenatal diagnosis of fetal tail and postabortum anatomical description
Authors: Grangé G. , Tantau J. , Pannier E. , Aubry M.‐C. , Viot G. , Fallet‐Bianco C. , Terrasse G. , Cabrol D.
Published: March 2003

Fetal ultrasound examination at 13 weeks of gestation demonstrated a homogeneously echogenic protrusion, or tail, 7 mm in length, in the sacral region. At 15 weeks, the ultrasound appearance was consistent with a regression of the tail and by 21 weeks it had completely disappeared. Severe intrauterine growth restriction with reduced uterine blood flow was diagnosed at 21 weeks and intrauterine death occurred at 24 weeks of gestation. Postmortem examination revealed a 4‐mm caudal appendage which contained no vertebrae on radiography. The appendage was located under and behind the last sacral vertebra suggesting a true vestigial tail with a delayed process of regression. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Uterine artery resistance and anxiety in the second trimester of pregnancy
Authors: Kent A. , Hughes P. , Ormerod L. , Jones G. , Thilaganathan B.
Published: March 2003

Objective

To investigate the association between maternal anxiety and uterine artery resistance index (RI) at 20 weeks of gestation.

Methods

Uterine artery blood flow was assessed using color Doppler ultrasound and maternal anxiety was measured using the Hospital Anxiety and Depression (HAD) scale in 96 healthy primigravid women attending consecutively for their routine 20‐week anomaly scan.

Results

The mean uterine artery RI was 0.54 (95% confidence interval, 0.52–0.56) and the median HAD anxiety score was 6 (range, 0–20). There was no association between RI and anxiety scores (r = 0.09, P = 0.36). Women scoring as definite cases of anxiety did not have a significantly elevated uterine artery RI or increased frequency of waveform notching compared to women with doubtful or no anxiety.

Conclusions

The data of this study do not suggest a significant association between maternal anxiety and uterine artery RI at 20 weeks of gestation in healthy primigravid women with normally developing pregnancies. A prospective cohort study would be useful to determine the nature of the relationship between maternal anxiety, alteration in uterine artery blood flow and abnormal pregnancy outcome. Copyright © 2002 ISUOG
A new fetal therapy for chylothorax: pleurodesis with OK‐432
Authors: Okawa T. , Takano Y. , Fujimori K. , Yanagida K. , Sato A.
Published: March 2003

We present a case of pleurodesis by intrapleural injection of OK‐432 for the treatment of fetal chylothorax at an early gestational age. OK‐432 injection achieved rapid and effective control of pleural effusion with no adverse effects. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Flecainide in the intrauterine treatment of fetal supraventricular tachycardia
Authors: Krapp M. , Baschat A. A. , Gembruch U. , Geipel A. , Germer U.
Published: March 2003

Objectives

To assess the efficacy of flecainide in the intrauterine treatment of fetal supraventricular tachycardia (SVT) with 1: 1 atrioventricular conduction.

Design

Twenty fetuses (21–35 weeks of gestation) with SVT ranging between 215 and 280 bpm were analyzed retrospectively. Fetuses received flecainide and digoxin as either first, second or third line therapy. Intracardiac blood flow, venous Doppler waveforms and cardiotocograms were evaluated before and after drug induced conversion to sinus rhythm.

Results

After initiation of combined flecainide and digoxin therapy, the median time interval until final conversion to sinus rhythm was 5 days (range, 0–14 days). The majority of fetuses (n = 15; 75%) converted to sinus rhythm within 7 days of treatment, whereas the remaining five (25%) showed initial reduction of the heart rate to 160–215 bpm over several days, with restoration of a triphasic venous blood flow pattern before late conversion within 7–14 days after initiation of flecainide treatment. One of these fetuses showed a decrease in fetal heart rate to 160–190 bpm without conversion to sinus rhythm but with resolution of hydrops. All fetuses survived.

Conclusions

Flecainide is safe and highly effective in the intrauterine treatment of hydropic fetuses with supraventricular tachycardia. Conversion into sinus rhythm can be expected 72 h after initiation of therapy but may take up to 14 days. Therefore therapy should be continued beyond 72 h, especially when an initial decrease of fetal heart rate is observed which may represent an early therapeutic response. Copyright © 2002 ISUOG
Maternal diastolic function in asymptomatic pregnant women with bilateral notching of the uterine artery waveform at 24 weeks' gestation: a pilot study
Authors: Valensise H. , Vasapollo B. , Novelli G. P. , Larciprete G. , Romanini M. E. , Arduini D. , Galante A. , Romanini C.
Published: March 2003

Objective

To study second‐trimester maternal cardiac adaptation in asymptomatic patients at risk, on the basis of abnormal uterine artery Doppler, for the development of gestational hypertension or having a small‐for‐gestational age fetus. Fetal and maternal outcomes were verified at the end of pregnancy.

Methods

Thirty‐six normotensive women with abnormal uterine artery waveforms underwent maternal echocardiographic examination at 24 weeks' gestation.

Results

Twenty‐one women (58.3%) subsequently showed normal outcome; 12 patients developed gestational hypertension (33.3%) and three (8.3%) had small‐for‐gestational age newborns. Left ventricular outflow tract, left ventricular diastolic dimensions and atrial and ventricular function were significantly lower in the pathological outcome group. Diastolic function parameters were significantly different between the two groups: peak mitral E‐wave and A‐wave and A‐wave duration showed lower values in the pathological outcome group. Isovolumetric relaxation time of the left ventricle was significantly longer in the pathological outcome group. The prevalence of an altered geometric pattern was 14.3% (3/21) in the normal and 80% (12/15) in the pathological outcome groups (P < 0.001).

Conclusions

Women who subsequently develop a complication of pregnancy tend to display abnormal cardiac adaptation. An abnormal placentation process, expressed by an elevated resistance index and the presence of notches in the uterine artery waveform, are likely to cause an adaptative mechanism involving the whole cardiovascular system. A pathological outcome of pregnancy is associated with the failure of this process. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Screening for trisomy 21 by fetal nuchal translucency and maternal age: a multicenter project in Germany, Austria and Switzerland
Authors: Gasiorek‐Wiens A. , Tercanli S. , Kozlowski P. , Kossakiewicz A. , Minderer S. , Meyberg H. , Kamin G. , Germer U. , Bielicki M. , Hackelöer B. J. , Sarlay D. , Kuhn P. , Klapp J. , Bahlmann F. , Pruggmayer M. , Schneider K. T. M. , Seefried W. , Fritzer E. , von Kaisenberg C. S.
Published: March 2003

Objective

To examine the effectiveness of screening for trisomy 21 by a combination of maternal age and fetal nuchal translucency thickness at 10–14 weeks of gestation in Germany, Austria and Switzerland.

Methods

This was a multicenter study of screening for trisomy 21 by a combination of maternal age and fetal nuchal translucency thickness at 10–14 weeks of gestation. All the sonographers involved in the study had received The Fetal Medicine Foundation Certificate of Competence in the 10–14‐week scan. Fetal nuchal translucency thickness and crown–rump length were measured in 23 805 singleton pregnancies with live fetuses. In each case the risk for trisomy 21 was estimated on the basis of maternal age and fetal nuchal translucency thickness for crown–rump length with the use of The Fetal Medicine Foundation's software. The distribution of estimated risk was determined and the sensitivity and false‐positive rate for a risk cut‐off of 1 in 300 was calculated.

Results

Fetal nuchal translucency thickness was successfully measured in all 23 805 pregnancies and outcome was available in 21 959. The median maternal age was 33 (range 15–49) years and in 7935 (36.1%) the age was 35 years or greater. The median gestation at screening was 12 (10–14) weeks and the median fetal crown–rump length was 61 (range 38–84) mm. The estimated risk for trisomy 21 based on maternal age and fetal nuchal translucency thickness for crown–rump length was 1 in 300 or greater in 13.0% (2800 of 21 475) normal pregnancies, in 87.6% (184 of 210) of those with trisomy 21 and in 87.2% (239 of 274) with other chromosomal defects.

Conclusions

In Germany, Austria and Switzerland the results of screening for chromosomal defects by measurement of fetal nuchal translucency thickness, in centers with appropriately qualified sonographers and using The Fetal Medicine Foundation's software, are similar to those reported in the UK using the same methodology.Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Normal cardiac flow velocities at 14–16 weeks of gestation measured by transvaginal ultrasound
Authors: Ben‐Ami M. , Peleg D. , Haddad S. , Perlitz Y.
Published: March 2003

Objective

Doppler ultrasound has been used to study the flow velocities through the valves and arteries of the fetal heart. Using transvaginal sonography, we sought to determine normal values for flow velocities through the fetal heart valves at 14–16 weeks of gestation.

Methods

Eighty‐seven normal fetuses were examined. The flow velocity waveforms were visualized using Doppler ultrasound with the sample volume calipers placed just distally to the four fetal valves. Peak E‐ and A‐wave velocities were recorded for the tricuspid and mitral valves and peak systolic flow velocities were recorded for the ascending aorta and pulmonary arteries. Linear regression for comparison of flow velocities with gestational age was performed.

Results

There was no significant correlation between any of the velocities and gestational age.

Conclusions

Flow velocities through the fetal cardiac valves remain unchanged at 14–16 weeks of gestation as measured by transvaginal Doppler sonography. Copyright © 2002 ISUOG
Identification of a novel gene, Mblk‐1, that encodes a putative transcription factor expressed preferentially in the large‐type Kenyon cells of the honeybee brain
Authors: Takeuchi Hideaki , Kage Eriko , Sawata Miyuki , Kamikouchi Azusa , Ohashi Kazuaki , Ohara Maya , Fujiyuki Tomoko , Kunieda Takekazu , Sekimizu Kazuhisa , Natori Shunji , Kubo Takeo
Published: March 2003

Mushroom bodies (MBs) are considered to be involved in higher‐order sensory processing in the insect brain. To identify the genes involved in the intrinsic function of the honeybee MBs, we searched for genes preferentially expressed therein, using the differential display method. Here we report a novel gene encoding a putative transcription factor (Mblk‐1) expressed preferentially in one of two types of intrinsic MB neurones, the large‐type Kenyon cells, which makes Mblk‐1 a candidate gene involved in the advanced behaviours of honeybees. A putative DNA binding motif of Mblk‐1 had significant sequence homology with those encoded by genes from various animal species, suggesting that the functions of these proteins in neural cells are conserved among the animal kingdom.
Characterization of genomic DNA encoding cecropins from an Aedes albopictus mosquito cell line
Authors: Sun D. , Fallon A. M.
Published: March 2003

We used cDNA probes from Aedes albopictus mosquito cecropins AalCecA, B, and C to obtain genomic DNA copies and flanking DNA. Two gene copies (AalCecA1 and A2, AalCecB1 and B2, AalCecC1 and C2) encoding each of the three mature cecropin peptides were recovered. All these genes had a similar organization, into two exons interrupted by a single short intron. AalCecA1 and AalCecA2 encode mature protein products that differ by one amino acid residue, while AalCecB1 and AalCecB2, AalCecC1 and AalCecC2 encode identical mature cecropin peptides, respectively. The AalCecB and C gene pairs each share a common intergenic region of approximately 1 kb, with the two coding regions transcribed in opposite directions. With the exception of small insertions/deletions, the intergenic spacer region was highly conserved between the B1/C1 and B2/C2 clones. In transfected cells, 0.8 kb of upstream sequence was sufficient for inducible expression of AalCecA1. Within this region, a 28 bp sequence at positions –192 to –165 upstream of the transcription initiation site was found to contain a potential regulatory element. In electrophoretic mobility shift assays, synthetic double‐stranded DNA containing this 28 bp sequence retarded protein in cytoplasmic and nuclear extracts from C7‐10 cells.
Geographical patterns of genetic variation in two species ofStylosanthesSw. using amplified fragment length polymorphism
Authors: Sawkins M. C. , Maass B. L. , Pengelly B. C. , Newbury H. J. , Ford‐Lloyd B. V. , Maxted N. , Smith R.
Published: March 2003

Understanding the extent and distribution of genetic diversity within a species is essential for the development of effective conservation strategies. The objective of this study was to assess genetic variation using amplified fragment length polymorphisms (AFLP) in two species of the tropical legume genusStylosanthesSw. Annual,S. humilis(2n = 20) and perennial,S. viscosa(2n = 20) are found throughout tropical America, and are sympatric for much of their range of distribution. One hundred and eleven accessions, covering a wide geographical range, were selected for AFLP analysis. Binary data matrices derived from DNA banding patterns were analysed using the software programsntsys‐pcandarlequin. Several accessions were found to be misidentified. Of theS. humilisaccessions, the overall average similarity value was (0.72) slightly higher than the value obtained forS. viscosa(0.67). Cluster analysis and principal coordinate analysis grouped accessions from both species by geographical origin, with a few exceptions. Analysis of molecular variance (amova) inS. humilisrevealed 59.4% of the variation among groups formed from the cluster analysis. This was highly significant (P < 0.001). ForS. viscosaamovaalso revealed more variation among than within groups (66.5%). This was also highly significant (P < 0.001). The majority of accessions of both species conservedex situare of Brazilian and Venezuelan origin. This study has identified areas in Central America and Mexico for which novel genetic variation may be found and where conservation activities should be focused.
Parentage assignment and extra‐group paternity in a cooperative breeder: the Seychelles warbler (Acrocephalus sechellensis)
Authors: Richardson D. S. , Jury F. L. , Blaakmeer K. , Komdeur J. , Burke T.
Published: March 2003

We describe the development and initial application of a semiautomated parentage testing system in the Seychelles warbler (Acrocephalus sechellensis). This system used fluorescently labelled primers for 14 polymorphic microsatellite loci in two multiplex loading groups to genotype efficiently over 96% of the warbler population on Cousin island. When used in conjunction with the programcervus, this system provided sufficient power to assign maternity and paternity within the Seychelles warbler, despite the complications associated with its cooperative breeding system and a relatively low level of genetic variation. Parentage analyses showed that subordinate ‘helper’ females as well as the dominant ‘primary’ females laid eggs in communal nests, indicating that the Seychelles warbler has an intermediate level of female reproductive skew, in between the alternative extremes of helper‐at‐the‐nest and joint nesting systems. Forty‐four per cent of helpers bred successfully, accounting for 15% of all offspring. Forty per cent of young resulted from extra‐group paternity.
Microsatellite analysis of medfly bioinfestations in California
Authors: Bonizzoni M. , Zheng L. , Guglielmino C. R. , Haymer D. S. , Gasperi G. , Gomulski L. M. , Malacrida A. R.
Published: March 2003

The Mediterranean fruit fly, Ceratitis capitata, is a destructive agricultural pest with a long history of invasion success. This pest has been affecting different regions of the United States for the past 30 years, but a number of studies of medfly bioinfestations has focused on the situation in California. Although some progress has been made in terms of establishing the origin of infestations, the overall status of this pest in this area remains controversial. Specifically, do flies captured over the years represent independent infestations or the persistence of a resident population? We present an effort to answer this question based on the use of multilocus genotyping. Ten microsatellite loci were used to analyse 109 medflies captured in several infestations within California between 1992 and 1998. Using these same markers, 242 medflies from regions of the world having ‘established’ populations of this pest including Hawaii, Guatemala, El Salvador, Ecuador, Brazil, Argentina and Peru, were also analysed. Although phylogenetic analysis, amova analysis, the immanc assignment test and geneclass exclusion test analysis suggest that some of the medflies captured in California are derived from independent invasion events, analysis of specimens from the Los Angeles basin provides support for the hypothesis that an endemic population, probably derived from Guatemala, has been established.
Population genetic structure of the malaria mosquito Anopheles arabiensis across Nigeria suggests range expansion
Authors: Onyabe D. Y. , Conn J. E.
Published: March 2003

Ten microsatellite loci, four located within and six outside chromosome inversions, were employed to study the genetic structure of Anopheles arabiensis across the ecological zones of Nigeria (arid savannah in the north gradually turns into humid forest in the south). Regardless of location within or outside inversions, genetic variability at all loci was characterized by a reduction in both the number of alleles per locus and heterozygosity from savannah to forest. Across all loci, all but one allele in the forest also occurred in the savannah, whereas at least 78 alleles in the savannah were missing in the forest. Genetic differentiation increased with geographical distance; consequently, genetic distances between zones exceeded those within zones. The largest genetic distances were between localities at the extremes of the transect (range FST = 0.196–0.258 and RST = 0.183–0.468) and were as large as those between A. arabiensis and Anopheles gambiae s.s. Gene flow across the country was very low, so that Nm between the extremes of the transect was < 1. These data suggest that A. arabiensis has extended its range from the savannah into the forest during which it experienced a reduction in effective population size due to sequential founder effects. Gene flow post range expansion appears too restricted by geographical distance to homogenize the gene pool of A. arabiensis across Nigeria.
Random amplified polymorphic DNA and amplified fragment length polymorphism assessment of genetic variation in Nicaraguan populations of Pinus oocarpa
Authors: Díaz V. , Muñiz L. M. , Ferrer E.
Published: March 2003

Pinus oocarpa is the most widely distributed pine species of Mexico and Central America. The natural populations of Nicaragua have been affected by extensive human activities. As a consequence, their size has been reduced, and there is a serious threat to the development of mature woodland. Knowledge of population structures and the genetic diversity of the species is required for the design of sustainable use and conservation strategies. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers were used to assess the genetic variation among 10 populations from three geographical regions of Nicaragua. Both markers revealed high levels of diversity in these populations. GST values and analyses of molecular variance (amova) found that most variation was within populations but there is still a significant differentiation between populations indicating that the populations sampled cannot be considered a single panmictic unit. The partitions created by amova also showed that there was little differentiation between populations of different regions, although cluster analyses based on RAPDs and AFLPs indicated a closer relationship among most of the populations from a same geographical region. Management of P. oocarpa in Nicaragua should be aimed to maintain the high degree of genetic variation within individual populations that is still observed even in some of these highly degraded populations.
Organelle DNA phylogeography of Cycas taitungensis, a relict species in Taiwan
Authors: Huang S. , Chiang Y. C. , Schaal B. A. , Chou C. H. , Chiang T. Y.
Published: March 2003

The phylogegraphic pattern of Cycas taitungensis, an endemic species with two remaining populations in Taiwan, was investigated based on genetic variability and phylogeny of the atpB‐rbcL noncoding spacer of chloroplast DNA (cpDNA) and the ribosomal DNA (rDNA) internal transcribed spacer (ITS) of mitochondrial DNA (mtDNA). High levels of genetic variation at both organelle loci, due to frequent intramolecular recombination, and low levels of genetic differentiation were detected in the relict gymnosperm. The apportionment of genetic variation within and between populations agreed with a migrant‐pool model, which describes a migratory pattern with colonists recruited from a random sample of earlier existing populations. Phylogenies obtained from cpDNA and mtDNA were discordant according to neighbour‐joining analyses. In total four chlorotypes (clades I–IV) and five mitotypes (clades A–E) were identified based on minimum spanning networks of each locus. Significant linkage disequilibrium in mitotype–chlorotype associations excluded the possibility of the recurrent homoplasious mutations as the major force causing phylogenetic inconsistency. The most abundant chlorotype I was associated with all mitotypes and the most abundant mitotype C with all chlorotypes; no combinations of rare mitotypes with rare chlorotypes were found. According to nested clade analyses, such nonrandom associations may be ascribed to relative ages among alleles associated with the geological history through which cycads evolved. Nested in networks as interior nodes coupled with wide geographical distribution, the most dominant cytotypes of CI and EI may represent ancestral haplotypes of C. taitungensis with a possible long existence prior to the Pleistocene glacial maximum. In contrast, rare chlorotypes and mitotypes with restricted and patchy distribution may have relatively recent origins. Newly evolved genetic elements of mtDNA, with a low frequency, were likely to be associated with the dominant chlorotype, and vice versa, resulting in the nonrandom mitotype–chlorotype associations. Paraphyly of CI and EI cytotypes, leading to the low level of genetic differentiation between cycad populations, indicated a short period for isolation, which allowed low possibilities of the attainment of coalescence at polymorphic ancestral alleles.
Adult habitat preferences, larval dispersal, and the comparative phylogeography of three Atlantic surgeonfishes (Teleostei: Acanthuridae)
Authors: Rocha Luiz A. , Bass Anna L. , Robertson D. Ross , Bowen Brian W.
Published: March 2003

Although many reef fishes of the tropical Atlantic are widely distributed, there are large discontinuities that may strongly influence phylogeographical patterns. The freshwater outflow of the Amazon basin is recognized as a major barrier that produces a break between Brazilian and Caribbean faunas. The vast oceanic distances between Brazil and the mid‐Atlantic ridge islands represent another formidable barrier. To assess the relative importance of these barriers, we compared a fragment of the mitochondrial DNA (mtDNA) cytochrome b gene among populations of three species of Atlantic surgeonfishes: Acanthurus bahianus, A. chirurgus and A. coeruleus. These species have similar life histories but different adult habitat preferences. The mtDNA data show no population structure between Brazil and the mid‐Atlantic islands, indicating that this oceanic barrier is readily traversed by the pelagic larval stage of all three surgeonfishes, which spend ~45–70 days in the pelagic environment. The Amazon is a strong barrier to dispersal of A. bahianus (d = 0.024, ΦST = 0.724), a modest barrier for A. coeruleus (ΦST = 0.356), and has no discernible effect as a barrier for A. chirurgus. The later species has been collected on soft bottoms with sponge habitats under the Amazon outflow, indicating that relaxed adult habitat requirements enable it to readily cross that barrier. A limited ability to use soft bottom habitats may also explain the low (but significant) population structure in A. coeruleus. In contrast, A. bahianus has not been collected over deep sponge bottoms, and rarely settles outside shallow reefs. Overall, adult habitat preferences seem to be the factor that differentiates phylogeographical patterns in these reef‐associated species.
Social structure in migrating humpback whales (Megaptera novaeangliae)
Authors: Valsecchi Elena , Hale Peter , Corkeron Peter , Amos William
Published: March 2003

Although largely solitary, humpback whales exhibit a number of behaviours where individuals co‐operate with one another, for example during bubble net feeding. Such cases could be due to reciprocal altruism brought on by exceptional circumstances, for example the presence of abundant shoaling fish. An alternative explanation is that these behaviours have evolved through kin selection. With little restriction to either communication or movement, diffuse groups of relatives could maintain some form of social organization without the need to travel in tight‐nit units. To try to distinguish between these hypotheses, we took advantage of the fact that migrating humpback whales often swim together in small groups. If kin selection is important in humpback whale biology, these groups should be enriched for relatives. Consequently, we analysed biopsy samples from 57 groups of humpback whales migrating off Eastern Australia in 1992. A total of 142 whales were screened for eight microsatellite markers. Mitochondrial DNA sequences (371 bp) were also used to verify and assist kinship identification. Our data add support to the notion that mothers travel with their offspring for the first year of the calf’s life. However, beyond the presence of mother‐calf/yearling pairs, no obvious relatedness pattern was found among whales sampled either in the same pod or on the same day. Levels of relatedness did not vary between migratory phases (towards or away from the breeding ground), nor between the two sexes considered either overall or in the north or south migrations separately. These findings suggest that, if any social organization does exist, it is formed transiently when needed rather than being a constant feature of the population, and hence is more likely based on reciprocal altruism than kin selection.
Steroid hormone levels and bi‐directional sex change in Gobiodon histrio
Authors: Kroon F. J. , Munday P. L. , Pankhurst N. W.
Published: March 2003

Sex change in the coral‐dwelling goby Gobiodon histrio was induced by placing two adult fish of the same sex on a coral colony. The sex change of individual fish was confirmed using histology, and whole‐body concentrations of the gonadal steroids testosterone (T), 11‐ketotestosterone (11‐KT), and 17β‐oestradiol (E2) were examined. The results show that T, 11‐KT and E2 occurred in both female and male G. histrio. E2 concentration in females was twice that in males, while concentrations of T did not differ between the sexes. Contrary to predictions, concentrations of T and E2 did not differ between fish that changed sex and those that did not. Most samples had 11‐KT concentrations below minimum levels of detection ( i.e. <0·15 ng ml−1) and were therefore not analysed statistically. The results suggest that: (i) specific activation or de‐activation of the T–E2 (aromatase) pathway is a probable candidate for mediating serial adult sex change in G. histrio, and (ii) low levels of 11‐KT may be important in allowing serial adult sex change in G. histrio.
Presence of 1 year‐old dusky groupers along the French Mediterranean coast
Authors: Bodilis P. , Ganteaume A. , Francour P.
Published: March 2003

One year‐old dusky groupers Epinephelus marginatus have been recently and regularly observed in different areas along the French Mediterranean coast.