bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of phosphoramide mustard and acrolein, cytotoxic metabolites of cyclophosphamide, on mouse limb development in vitro
Authors: Hales Barbara F.
Published: June 2005

Phosphoramide mustard and acrolein are toxic and reactive metabolites of the widely used anticancer drug and known teratogen cyclophosphamide. To study the mechanism(s) involved and to determine which of the active metabolites of cyclophosphamide is responsible for the production of limb malformations, the effects of exposure of cultured limb buds to phosphoramide mustard and acrolein were investigated. Fore‐ and hindlimbs were excised from ICR mice on day 12 of gestation and cultured in roller bottles for 6 days. Limbs were exposed to either phosphoramide mustard or acrolein (10 or 50 μg/ml) for the first 20 hours of the culture period. Exposure to phosphoramide mustard produced limb reduction malformations in both the fore‐ and hindlimbs; total limb bone area was greatly reduced, while the relative contribution of the paw to this area in forelimbs was increased. There was a fourfold reduction in both DNA and RNA; protein content was reduced only by one‐half. Alkaline phosphatase activity was significantly decreased in fore‐ and hindlimbs exposed to phosphoramide mustard, whereas creatine phosphokinase activity was only reduced in hindlimbs in the limbs exposed to the higher concentration of phosphoramide mustard. Exposure to acrolein also produced malformed limbs with a mangled appearance; however, total limb bone area and the relative contribution of the long bones versus paw structures were not altered. Acrolein exposure had little effect on growth parameters such as DNA (decreased only in hindlimbs exposed to 50 μg/ml), RNA (increased in hindlimbs exposed to 50 μg/ml), or protein content. Alkaline phosphatase and creatine phosphokinase activities were not altered in acrolein‐exposed fore‐ or hindlimbs. Thus, phosphoramide mustard and acrolein have dramatically different effects on developing limbs in vitro; this observation may indicate that they have different targets and/or mechanisms of action as teratogens in the limb. The effects of phosphoramide mustard are very simlar to those of “activated” cyclophosphamide (4‐hydroperoxycyclophosphamide).
Lack of teratogenicity of trans‐2‐ene‐valproic acid compared to valproic acid in rats
Authors: Vorhees Charles V. , Acuff‐Smith Karen D. , Weisenburger Walter P. , Minck Daniel R. , Berry James S. , Setchell Kenneth D. R. , Nau Heinz
Published: June 2005

The teratogenicity of trans‐2‐ene‐valproic acid (300 and 400 mg/kg) was compared with that of valproic acid (VPA; 300 mg/kg) and controls (corn oil) administered by gavage to Sprague‐Dawley CD rats on embryonic (E) days 7–18. At the 300 mg/kg dose, trans‐2‐ene‐VPA produced no change in maternal weight, number of implantations, proportion of resorptions, proportion of malformations, or fetal weight. By contrast, the same dose of VPA (300 mg/kg) reduced maternal weight during gestation, increased malformations (12.0% vs. 0.7% in controls), and reduced fetal body weight by 25.1%. An even higher dose of trans‐2‐ene‐VPA (400 mg/kg) produced a reduction in maternal body weight during treatment and reduced fetal body weight (by 7.9%), but did not increase resorptions or malformations in the fetuses. On day E18, maternal serum drug concentrations of VPA were higher in the VPA‐treated group compared with those of trans‐2‐ene‐VPA in the trans‐2‐ene‐VPA‐treated groups at 1 hr posttreatment. At 6 hr posttreatment the reverse was seen. trans‐2‐ene‐VPA may be absorbed more rapidly and distributed differently than VPA. Overall, the data support the view that trans‐2‐ene‐VPA at equal or higher doses than VPA is not teratogenic in rats.
Relationship between fetal weight and malformation in developmental toxicity studies
Authors: Ryan Louise M. , Catalano Paul J. , Kimmel Carole A. , Kimmel Gary L.
Published: June 2005

Exposure to developmental toxicants may cause fetal malformations, increase prenatal death rates and reduce fetal weight at term. However, there has been little formal study of the relationship among these effects. Certainly, no statistical methods are currently available to jointly analyze these effects of exposure. As a preliminary step in developing such methods, simple exploratory analyses were conducted using a series of ten studies conducted for the National Toxicology Program. Because fetal weight and malformation status were both reported for all live fetuses, the data permitted an exploration of the correlation between these two outcomes. The data show a clear pattern wherein malformed fetuses tended to be lighter at term than nonmalformed fetuses. While these patterns cannot be used to draw inferences regarding the biological relationship between fetal weight and malformation, they do suggest the potential value in developing statistical models for the joint effect of exposure on fetal weight and malformations.
Craniofacial alterations in adult rats prenatally exposed to ethanol
Authors: Edwards Harold G. , Dow‐Edwards Diana L.
Published: June 2005

The rat was studied to determine whether gestational exposure to moderate amounts of ethanol produces permanent craniofacial malformations. Pregnant Long‐Evans rats were fed a liquid diet containing 35% ethanol‐derived calories or an isocaloric liquid diet between gestation days 6 and 20. Various dimensions of skulls and mandibles from adult male offspring were measured. All measurements taken in the parasagittal and coronal planes were significantly smaller in the ethanol‐exposed rats than in the offspring of pair‐fed controls. None of the vertical measurements was significantly altered. This report demonstrates that gestational exposure to ethanol in rats, at doses which produce lasting behavioral effects, also produces a specific constellation of craniofacial dysmorphisms without concomitant decreases in body weight.
Relationship between gestational cocaine use and pregnancy outcome: A meta‐analysis
Authors: Lutiger Beatrix , Graham Karen , Einarson Thomas R. , Koren Gideon
Published: June 2005

Despite a growing number of studies that have investigated the reproductive effects of maternal cocaine use, a homogeneous pattern of fetal effects has not been established and there is little consensus on the adverse effects of the drug. We used meta‐analysis to evaluate the reproductive risks of cocaine. We reviewed the 45 scientific papers published in the English language dealing with effects of cocaine used during pregnancy on pregnancy outcome in humans, and identified 20 papers eligible for meta‐analysis (cocaine use in pregnancy, pregnancy/fetal outcome studies, human studies, original work, cohort or case control studies, control group present, English language). Our analysis revealed that very few adverse reproductive effects could be shown to be significantly associated with cocaine use by polydrug users when compared to control groups of polydrug users not using cocaine [genitourinary malformations; odds ratio of 6.08 (95% CI 1.18–31.3); gestation age: Cohen's d 0.37 (CI 0.2–0.55)]. When the control groups consisted of no drug users, the polydrug users abusing cocaine had a higher risk for spontaneous abortions [odds ration 10.50 (CI 11.74–64.1)]. Similarly, comparison of users of cocaine alone or no drug users revealed a higher risk for in utero death, in addition to genitourinary tract malformations. Analysis of continuous variables (head circumference, gestational age, birth weight and length) revealed that the effect size was dependent upon the nature of the comparison. Comparison of cocaine users to no drug users consistently yielded a medium effect size (Cohen's d) between 0.50 and 0.58, while comparison of polydrug/cocaine users to polydrug/no cocaine users provided effect sizes small to non existent (0.06–0.37). These discrepancies suggest that a variety of adverse reproductive effects commonly quoted to be associated with maternal use of cocaine may be caused by confounding factors clustering in cocaine users.
Long bone development in extrinsic fetal akinesia: An experimental study in rat fetuses subjected to oligohydramnios
Authors: Palacios José , Rodríguez José I. , Ruiz Antonio , Sanchez Miguel , Alvarez Ignacio , Demiguel Enrique
Published: June 2005

The transverse grwoth of long bones during intrauterine development was studied in rat fetuses subjected to experimental oligohydramnios in order to determine wheter the skeletal changes, if any, in extrinsic fetal akinesia were similar to those observed in curarized rat fetuses with the fetal akinesia deformation sequence. Oligohydramnios was induced by daily extraction of amniotic fluid from day 17 of gestation until term. Experimental fetuses were compared with a sham‐operated control group. The total area and perimeter, the absolute and relative amount of periosteum and bone trabeculae, the major and minor axes, and the elongation factor were measured in histological cross sections of the femoral metaphysis and diaphysis with an IBAS 1 image analysis system. Rat fetuses in the experimental group showed multiple articular contractures, redundant skin, and lung hypoplasia, a phenotype consistent with the oligohydramnios sequence. No alterations in femoral shape and transverse growth of the metaphysis and diaphysis were noted in these fetuses. These results suggest that the main mechanical factor related to fetal bone modeling is muscular strength, while motion would be mainly involved in fetal joint development. © 1992 Wiley‐Liss, Inc.
Strain‐dependent effect of ethanol on ventricular septal defect frequency in white leghorn chick embryos
Authors: Bruyere Harold J. , Stith Charles E.
Published: June 2005

We have tested the potential of a single dose of ethanol (0.20ml 50% ethanol in chick Ringer's saline (CRS) administered into the air sac) to produce ventricular septal defect (VSD) in three distinct commercially available strains of White Leghorn chick embryo: stress‐resistant Dekalb Delta strain, Hy‐Vac SPF type V, and Hy‐Vac SPF type L. Eggs were controlled for both size and developmental stage (Hamburger‐Hamilton stage 18–19) at time of injection. The frequency of VSD in Dekalb Delta embryos was 4.0% (1/25), in Hy‐Vac SPF type L embryos 9.1% (3/33), and in Hy‐Vac SPF type V embryos 38.9% (14/36). Statistical analysis with the two‐tailed Fisher Exact Test indicated that frequencies were not significantly different (P = 0.3215) when Dekalb Delta and Hy‐Vac type L embryos were compared. However, the frequency of VSD for Hy‐Vac type V embryos was significantly greater than that for either the Dekalb Delta or the Hy‐Vac type L embryos (P <0.005). All VSDs observed were located within the crista supraventricularis. When Hy‐Vac SPF type V embryos were exposed to either 0.20 ml 50% ethanol in CRS or to 0.20 ml CRS (controls), ethanol‐treated embryos showed a VSD incidence of 34.1% compared with a 3.6% incidence in the controls (P = 0.0017). These data suggest that ethanol is the cause of VSD in this strain. From the results of this study, we are led to conclude that different commercial strains of White Leghorn chick embryo show different susceptibilities to the induction of VSD by ethanol. © 1993 Wiley‐Liss, Inc.
Exercise at high temperature causes maternal hyperthermia and fetal anomalies in rats
Authors: Sasaki Junichi , Yamaguchi Akihiko , Nabeshima Yuichi , Shigemitsu Sadahiko , Mesaki Noboru , Kubo Takeshi
Published: June 2005

Hyperthermia is thought to be a teratogen in many animal species and also in humans. It has been reported that hyperthermia caused by sauna, hot tub, or fever during the early stages of pregnancy is related to an increased risk or neural tube defects. During exercise, especially in hot conditions, body temperature can also rise to fairly high levels. Thus, we can surmise that hyperthermia induced by exercise can also cause fetal malformation.

To investigate this hypothesis, pregnant rats at 9 days of gestation were divided into four groups. In the first group, the animals were made to swim for 30 minutes in water at a temperature of 40.5°C. In the second group, they were restrained and immersed in water for the same time at the same temperature. In the third group, the rats were forced to swim in water at 36.0°C. The fourth group were controls. The core temperature of the rats was measured during these procedures. On the 18th gestational day, fetuses were extracted by cesarean section. The elevation of maternal core temperature was significantly greater in the first group than in the other groups. In the first group, 69% of fetuses had various external anomalies. No anomalies were found in the other groups.

Our results show that exercise in hot conditions caused the elevation of core temperature and resulted in fetal anomalies in rats. © 1995 Wiley‐Liss, Inc.
Seasonal changes in epididymis and the effects of FSH and testosterone in the spiny‐tailed lizard, Uromastix hardwicki
Authors: Arslan M. , Jalali S. , Nasreen T. , Qazi M. H.
Published: June 2005

Seasonal changes in epididymal weight and histology were studied in relation to testicular function in the adult spiny‐tailed lizard, Uromastix hardwicki, over a period of 1 year. The eipdidymal weights, tubular diameter, and epithelial height increased in March, reaching a peak in April. This peak coincided with sperm maturation, elevated plasma testosterone levels, and release of sperm into the epididymis. The epididymal weights decreased in May following a sudden regression of the testis early in the month. The epididymal weights decreased further during June and remained low until February. The diameter of the duct and the height of the epithelial cells also decreased in May and the epididymal epithelium maintained a low histological profile from June to February. The fall testicular recrudescence was not accompanied by a change either in the weight or the histological structure of the epididymis. Administration of oFSH (0.1 mg) daily for 7 days during the sexually quiescent period induced a significant increase in the weight of the epididymis and epithelial height of the duct. Administration of testosterone alone, (2.0 mg) daily for the same period and under identical conditions, did not induce a change in the weight of epididymis or its histology. A possible permissive role of gonadotrophin in the hormonal regulation of the lizard epididymis has been suggested.
Pulmonary aspergillosis in three species of dolphin
Authors: Joseph Brian E. , Cornell Lanny H. , Simpson John G. , Migaki George , Griner Lynn
Published: June 2005

The clinical history, laboratory data, and gross and histological findings are described and discussed for three cases of fatal pulmonary aspergillosis in three species of dolphins. Procedures for obtaining a definitive antemortem diagnosis, treatment, and pathogenesis are discussed.
Methods of semen collection in an ambulatory greater one‐horned rhinoceros (rhinoceros unicornis)
Authors: Schaffer N. E. , Beehler B. , Jeyendran R. S. , Balke B.
Published: June 2005

Illegal poaching and reduced habitats have led to the endangered status of rhinoceroses. Collection of semen for preservation and future artificial insemination would therefore increase the reproductive potential of the rhinoceros. Although various collection methods have been attemped with individual rhinos, comparison between methods on a single animal have not been reported. This report details the application of six semen collection techniques on an unsedated and unrestrained greater one‐horned rhino. The methods included different types of penile and/or rectal stimulation. Artificial vaginas and an inflatible probe for electroejaculation were specially constructed for semen collection. Of the various methods employed, penile massage consistently resulted in sperm‐poor seminal fluid, but when preceded by either rectal massage or electroejaculation, seminal fluid with high sperm concentration was obtained.
Gross anatomy of the reproductive tract of female black (Diceros bicornis michaeli) and white rhinoceros (Ceratotherium simum simum)
Authors: Godfrey R. W. , Pope C. E. , Dresser B. L. , Olsen J. H.
Published: June 2005

Reproductive tracts were collected from three black rhinoceros and two white rhinoceros at necropsy. All females were nulliparous, except for one primiparous white rhinoceros. The animals ranged in age from 7 days to 28 years. All nulliparous animals had a constriction in the vaginal canal, which appeared to be a hymen. The primiparous female had only remnants of a hymen. The total length of the tract averaged 102 cm in three adult animals (≥21 years old). The distance from the vulva to the external cervical os averaged 40 cm in these animals. The endometrium of a 28‐year‐old nulliparous black rhinoceros and a 27‐year‐old nulliparous white rhinoceros exhibited signs of hyperplasia, whereas this condition was not present in the other animals. It is not known if this condition was related to the fertility of these animals. The cervix of the rhinoceros was firm, and the lumen followed a very tortuous path through eccentric rings of tissue. Visual examination of the ovaries revealed the presence of surface follicles on the ovaries in both species. The overall size of the reproductive tract, especially the vagina and uterine horns, and the extremely tortuous cervical lumen will present obstacles that must be overcome when developing artificial insemination and embryo transfer proceduers for use in rhinoceros.
Feasibility of characterizing reproductive events in large nondomestic species by transrectal ultrasonic imaging
Authors: Adams G. P. , Plotka E. D. , Asa C. S. , Ginther O. J.
Published: June 2005

The feasibility of using transrectal ultrasonography for imaging the in situ morphology of the reproductive tract of females of several large nondomestic and endangered species was studied. Two black (Diceros bicornis) and 1 white (Diceros simus) rhinoceros, 2 Asian (Elaphus maximus) and 2 African (Loxodonta africana) elephants, 4 banteng (Bos javanicus), 1 gaur (Bos taurus), 1 giraffe (Giraffa camelopardalis), and 1 bactrian camel (Camelus bactrianus) were examined. Real‐time ultrasonic images were obtained for the following structures: 1) rhinoceros—corpus luteum, ovarian follicles, uterus, cervix, and early conceptus, 2) elephants—posterior uterus and cervix, 3) banteng and gaur—corpus luteum, ovarian follicles, uterus, cervix, and conceptus, 4) giraffe—posterior uterus, placentomes, and late conceptus, 5) camel—posterior uterus, fetal fluids, and fetal membranes. Individual ovarian follicles were identified and monitored over a 34 day observational period in 1 nontranquilized white rhinoceros. Difficulties and limitations in viewing the ovaries in the elephants were attributed to operator inexperience and to the size, positioning, and demeanor of the animals. Pregnancy was detected in 1 black rhinoceros (27 days), 1 banteng cow (48 days), the giraffe (13 months), and in the bactrian camel (approximately 3½ months). Impending embryonic loss was suspected in the banteng cow because a heartbeat was not detected in the embryo proper; the cow was subsequently diagnosed nonpregnant by transrectal palpation 20 days later. It is concluded that the ability afforded by transrectal ultrasonography to detect and measure ovarian structures and changes in morphology of the tubular genitalia and conceptus provides a research methodology for the elucidation of certain aspects of reproductive biology, and a clinical modality for reproductive management and assisted fertilization programs of large nondomestic species.
The effects of temporary cover on the behavior of socially housed stumptailed macaques (Macaca arctoides)
Authors: Estep Daniel Q. , Baker Suzanne C.
Published: June 2005

To examine the effects of the provision of temporary cover on the behavior of stumptailed macaques (Macaca arctoides), a single group of 26 animals was observed during 25 testing periods over 7.5 months. During each testing period, the group was observed under two conditions. In the Cover condition, two solid temporary walls 9.6 m in length, were erected within the animals' living compound. In the No‐Cover condition, the wall materials were stacked against one solid exterior wall of the compound. The provision of cover significantly reduced the levels of contact aggression, proximity between animals, and locomotion, and reduced the ability of the dominant male to monopolize copulations. It did not effect other measures of affiliation. Inconsistencies between these results and those of other published studies suggest that, while cover can have a significant influence on some kinds of social behavior in some situations, generalizations about the benefits of providing cover to captive animals may be premature.
Fecal progestagen evaluations to monitor the estrous cycle and pregnancy in the okapi (Okapia johnstoni)
Authors: Schwarzenberger Franz , Patzl Martina , Francke Richard , Ochs Andreas , Buiter Rob , Schaftenaar Willem , De Meurichy Walter
Published: June 2005

The present study was conducted to establish a noninvasive method of reproductive monitoring in the okapi (Okapia johnstoni). Fecal samples were collected three times a week from nonpregnant okapis (n = 3) for periods of 2, 9, and 23 months, respectively, and for 2 months each from pregnant okapis (n = 4) at different stages of gestation. Samples were analyzed with an enzyme‐immunoas‐say (EIA), using an antibody against pregnanediol, and the results are considered as measurements of unconjugated total immunoreactive progestagens (Pd‐Pgs). Mean values of Pd‐Pgs during the follicular (FP) and the luteal phases (LP) of the estrous cycles were 0.6 ± 0.1 μg/g and 6.1 −0.3 μg/g feces, respectively. Matings occurred at the terminations of the LP. By dividing the number of entire LPs into the time over which samples were available, average estrous cycle lengths in two okapis were estimated to be 15.5 (n = 11 LP) and 15.8 (n = 36 LP) days, respectively. In three animals, gestation lengths of 423, 424, and 431 days were calculated by observed matings. During days ‐280 to ‐220 before parturition, the fecal Pd‐Pgs constantly increased from about 20‐‐60 μg/g fecès. Values were 100‐‐350 μg/g during the last third of gestation. Values decreased in the week before parturition, and a continuous decline to FP values was observed within 3‐‐4 days postpartum. During the 2 months postpartum investigated in one animal, the Pd‐Pgs were in the FP range except one LP 3 weeks postpartum. It was concluded that fecal Pd‐Pgs in female okapis are present in a ratio of ∼1: 10:>100 during FP, LP, and late pregnancy, respectively. Their measurement by EIA enables noninvasive monitoring of the estrous cycle and pregnancy diagnosis. © 1993 Wiley‐Liss, Inc.
Electrophoretic and chromosomal variation in captive Asian elephants (Elephas maximus)
Authors: Hartl Günther B. , Kurt Fred , Hemmer Wolfgang , Nadlinger Karl
Published: June 2005

To investigate genetic diversity in captive Asian elephants (Elephas maximus), a total of 26 individuals from zoos in the German cities of Berlin, Hamburg, and Leipzig, and from Zürich, Switzerland, were investigated for electrophoretic variation at 44 presumptive blood protein and enzyme coding loci. The proportion of polymorphic loci (P = 4.6%) and average heterozygosity (H = 1.4%) in the specimens studied were very low. The distribution of alleles and genotypes suggested some genetic differentiation among the source populations of our elephants, most of which were wild born. Since our results are in accordance with those of a previous survey on wild populations, low genetic variation in the Asian elephant is not only associated with captive propagation. Together with differences in the incidence of alleles among populations, it is probably largely due to low effective sizes of wild Asian elephant stocks and to species‐specific breeding tactics. Standard karyotype analysis was carried out for 11 individuals, and in some cases, heterochromatin staining by Giemsa C‐banding and reverse fluorochrome staining were performed. Heterochromatin polymorphism was found in four chromosome pairs, including two satellited pairs, and is considered an important marker for population genetic investigations. One of the 11 individuals studied was found to be heterozygous for a centric fusion of two small acrocentrics. The implications of our results for breeding programs of Asian elephants are discussed. © 1995 Wiley‐Liss, Inc.
Clp upregulates transcription of engA gene encoding a virulence factor in Xanthomonas campestris by direct binding to the upstream tandem Clp sites
Authors: Hsiao Yi-Min , Liao Hsiu-Ying , Lee Mong-Chuan , Yang Tsuey-Ching , Tseng Yi-Hsiung
Published: June 2005

In Xanthomonas campestris, the causative agent of black rot in crucifers, the endoglucanase level is greatly decreased in the mutant deficient in Clp, a homologue of cyclic AMP receptor protein (CRP). It is established that Clp has the same DNA binding specificity as CRP at positions 5, 6, and 7 (GTG motif) of the DNA half site. In this study, the engA transcription initiation site was determined by the 5′ RACE method, and two consensus Clp‐binding sites, site I and site II centered at −69.5 and −42.5, respectively, were located. Transcriptional fusion assays indicated that Clp greatly activates engA transcription. Site‐directed mutagenesis indicated that position 5 of GTG motif in site II is essential for both DNA‐protein complex formation in electrophoretic mobility shift assays and engA transcription in vivo. In addition, mutation at position 5 of site I drastically reduces the promoter activity, indicating that binding of Clp to site I exerts a synergistic effect on the transcription activation by site II. engA appears to be the first X. campestris gene known to be activated by Clp via a direct binding to the promoter.
Cross‐talk between the TGFβ and Wnt signaling pathways in murine embryonic maxillary mesenchymal cells
Authors: Warner Dennis R. , Greene Robert M. , Pisano M. Michele
Published: June 2005

The transforming growth factor beta (TGFβ) and Wnt signaling pathways play central roles regulating embryogenesis and maintaining adult tissue homeostasis. TGFβ mediates its cellular effects through types I and II cell surface receptors coupled to the nucleocytoplasmic Smad proteins. Wnt signals via binding to a cell surface receptor, Frizzled, which in turn activates intracellular Dishevelled, ultimately leading to stabilization and nuclear translocation of β‐catenin. Previous studies have demonstrated several points of cross‐talk between the TGFβ and Wnt signaling pathways. In yeast two‐hybrid and GST‐pull down assays, Dishevelled‐1 and Smad 3 have been shown to physically interact through the C‐terminal one‐half of Dishevelled‐1 and the MH2 domain of Smad 3. The current study demonstrates that co‐treatment of murine embryonic maxillary mesenchyme (MEMM) cells with Wnt‐3a and TGFβ leads to enhanced reporter activity from TOPflash, a Wnt‐responsive reporter plasmid. Transcriptional cooperation between TGFβ and Wnt did not require the presence of a Smad binding element, nor did it occur when a TGFβ‐responsive reporter plasmid (p3TP‐lux) was transfected. Overexpression of Smad 3 further enhanced the cooperation between Wnt and TGFβ while overexpression of dominant‐negative Smads 2 and 3 inhibited this effect. Co‐stimulation with TGFβ led to greater nuclear translocation of β‐catenin, providing explanation for the effect of TGFβ on Wnt‐3a reporter activity. Wnt‐3a exerted antiproliferative activity in MEMM cells, similar to that exerted by TGFβ. In addition, Wnt‐3a and TGFβ in combination led to synergistic decreases in MEMM cell proliferation. These data demonstrate a functional interaction between the TGFβ and Wnt signaling pathways and suggest that Wnt activation of the canonical pathway is an important mediator of MEMM cell growth.
The solution structure of an N‐terminally truncated version of the yeast CDC24p PB1 domain shows a different β‐sheet topology
Authors: Leitner Dietmar , Wahl Martin , Labudde Dirk , Krause Gerd , Diehl Anne , Schmieder Peter , Pires José Ricardo , Fossi Michele , Wiedemann Urs , Leidert Martina , Oschkinat Hartmut
Published: June 2005

Phox and Bem1 (PB1) domains mediate protein–protein interactions via the formation of homo‐ or hetero‐dimers. The C‐terminal PB1 domain of yeast cell division cycle 24 (CDC24p), a guanine‐nucleotide exchange factor involved in cell polarity establishment, is known to interact with the PB1 domain occurring in bud emergence MSB1 interacting 1 (BEM1p) during the regulation of the yeast budding process via its OPR/PC/AID (OPCA) motif. Here, we present the structure of an N‐terminally truncated version of the Sc CDC24p PB1 domain. It shows a different topology of the β‐sheet than the long form. However, the C‐terminal part of the structure shows the conserved PB1 domain features including the OPCA motif with a slight rearrangement of helix α1. Residues which are important for the heterodimerization with BEM1p are structurally preserved.
The secondary electron acceptor of photosystem I in Gloeobacter violaceus PCC 7421 is menaquinone‐4 that is synthesized by a unique but unknown pathway
Authors: Mimuro Mamoru , Tsuchiya Tohru , Inoue Hidetoshi , Sakuragi Yumiko , Itoh Yuka , Gotoh Takanori , Miyashita Hideaki , Bryant Donald A. , Kobayashi Masami
Published: June 2005

The secondary electron acceptor of photosystem (PS) I in the cyanobacterium Gloeobacter violaceus PCC 7421 was identified as menaquinone‐4 (MQ‐4) by comparing high performance liquid chromatograms and absorption spectra with an authentic compound. The MQ‐4 content was estimated to be two molecules per one molecule of chlorophyll (Chl) a′, a constituent of P700. Comparative genomic analyses showed that six of eight men genes, encoding phylloquinone/MQ biosynthetic enzymes, are missing from the G. violaceus genome. Since G. violaceus clearly synthesizes MQ‐4, the combined results indicate that this cyanobacterium must have a novel pathway for the synthesis of 1,4‐dihydroxy‐2‐naphthoic acid.
Three‐dimensional architecture of phycobilisomes from Nostoc flagelliforme revealed by single particle electron microscopy
Authors: Yi Zhi-Wei , Huang Hui , Kuang Ting-Yun , Sui Sen-Fang
Published: June 2005

Phycobilisomes are protein complexes that harvest light and transfer energy to the photo system. Here, the three dimensional structure of intact phycobilisomes from Nostoc flagelliforme is studied by a combination of negative stain electron microscopy and cryo‐electron microscopy. Results show that the intact phycobilisomes are composed of a tricylindrical core and six rods. Each allophycocyanin cylinder presents a double‐layered structure when viewed from the side and a triangular shape when viewed from the top. These characteristics indicate that allophycocyanin trimers in the intact phycobilisomes are arranged into hexameric oligomers in a parallel manner.
Evaluation of a Skilled Birth Attendant pilot training program in Bangladesh
Authors: Bhuiyan A.B. , Mukherjee S. , Acharya S. , Haider S.J. , Begum F.
Published: June 2005

Objectives: An evaluation of the pilot project of the Skilled Birth Attendant (SBA) training program has been undertaken to assess the strengths and weaknesses of the training program, the after training performances of the selected SBAs and to ascertain the sustainability of the program. Methods: The study was conducted in three phases adopting both qualitative and quantitative methods: assessment of training program; evaluation of after training performances of SBAs; and evaluation of performance of providers in non‐SBA areas. Results: During the post‐training period it was observed that on an average the SBAs performed 3–4 deliveries per month. They were able to perform different life saving skills. In the areas served by the SBAs, they performed 29% deliveries and 47% were performed by the TBAs. In control areas TBAs performed 61% deliveries. Conclusion: Overall, the study points to the efficacy of SBAs over traditional hands and the societal need for SBAs.
Use of the De La Caffinière Prosthesis in Rheumatoid Trapeziometacarpal Destruction
Authors: SKYTTÄ E. T. , BELT E. A. , KAUTIAINEN H. J. , LEHTINEN J. T. , IKÄVALKO M. , MÄENPÄÄ H. M.
Published: June 2005

This study evaluated the outcome of the de la Caffinière prosthesis in patients with an inflammatory arthropathy affecting the trapeziometacarpal joint. The procedure was performed in 57 thumbs for rheumatoid arthritis (41 cases), juvenile chronic arthritis (ten cases), psoriatic arthritis (four cases) and other inflammatory joint diseases (two cases). Survival analysis with a revision procedure or radiographic implant failure as end points was performed. Five loosened cups and two permanently dislocated prostheses underwent revision surgery. These were managed with a bone graft and tendon interposition technique. Radiographic follow-up yielded four additional implant failures (two loosened cups, one loosened metacarpal stem and one permanent dislocation). The implant survival rate based on revision operation was 87% (95% CI 73–94) at 10 years, and the total radiographic and implant failure rate based on radiographic findings was 15% (95% CI 7–29) at 10 years.
Pulsed electromagnetic field treatments enhance the healing of fibular osteotomies
Authors: Midura Ronald J. , Ibiwoye Michael O. , Powell Kimerly A. , Sakai Yoshitada , Doehring Todd , Grabiner Mark D. , Patterson Thomas E. , Zborowski Maciej , Wolfman Alan
Published: June 2005

This study tested the hypothesis that pulsed electromagnetic field (PEMF) treatments augment and accelerate the healing of bone trauma. It utilized micro‐computed tomography imaging of live rats that had received bilateral 0.2 mm fibular osteotomies (∼0.5% acute bone loss) as a means to assess the in vivo rate dynamics of hard callus formation and overall callus volume. Starting 5 days post‐surgery, osteotomized right hind limbs were exposed 3 h daily to Physio‐Stim® PEMF, 7 days a week for up to 5 weeks of treatment. The contralateral hind limbs served as sham‐treated, within‐animal internal controls. Although both PEMF‐ and sham‐treatment groups exhibited similar onset of hard callus at ∼9 days after surgery, a 2‐fold faster rate of hard callus formation was observed thereafter in PEMF‐treated limbs, yielding a 2‐fold increase in callus volume by 13–20 days after surgery. The quantity of the new woven bone tissue within the osteotomy sites was significantly better in PEMF‐treated versus sham‐treated fibulae as assessed via hard tissue histology. The apparent modulus of each callus was assessed via a cantilever bend test and indicated a 2‐fold increase in callus stiffness in the PEMF‐treated over sham‐treated fibulae. PEMF‐treated fibulae exhibited an apparent modulus at the end of 5‐weeks that was ∼80% that of unoperated fibulae. Overall, these data indicate that Physio‐Stim® PEMF treatment improved osteotomy repair. These beneficial effects on bone healing were not observed when a different PEMF waveform. Osteo‐Stim®, was used. This latter observation demonstrates the specificity in the relationship between waveform characteristics and biological outcomes. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Decadal-scale changes in the climate and biota of the Pacific sector of the Southern Ocean, 1950s to the 1990s
Authors: AINLEY DAVID G. , CLARKE ELIZABETH D. , ARRIGO KEVIN , FRASER WILLIAM R. , KATO AKIKO , BARTON KERRY J. , WILSON PETER R.
Published: June 2005

Simultaneous, but contrary, decadal-scale changes in population trajectories of two penguin species in the western Pacific and Ross Sea sectors of the Southern Ocean, during the early/mid-1970s and again during 1988–89, correspond to changes in weather and sea ice patterns. These in turn are related to shifts in the semi-annual and Antarctic oscillations. Populations of the two ecologically dissimilar penguin species - Adélie Pygoscelis adeliae and emperor Aptenodytes forsteri - have been tallied annually since the 1950s making these the longest biological datasets for the Antarctic. Both species are obligates of sea ice and, therefore, allowing for the demographic lags inherent in the response of long-lived species to habitat or environmental variation, the proximate mechanisms responsible for the shifts involved changes in coastal wind strength and air and sea temperatures, which in turn affected the seasonal formation and decay of sea ice and polynyas. The latter probably affected such rates as the proportion of adults breeding and ultimately the reproductive output of populations in ways consistent with the two species' opposing sea ice needs. Corresponding patterns for the mid-1970s shift were reflected also in ice-obligate Weddell seal Leptonychotes weddelli populations and the structure of shallow-water sponge communities in the Ross Sea. The 1988–89 shift, by which time many more datasets had become available, was reflected among several ice-frequenting vertebrate species from all Southern Ocean sectors. Therefore, the patterns most clearly identified in the Pacific Sector were apparently spread throughout the high latitudes of the Southern Ocean.
Abiotic characterization and epilithic communities of a naturally enriched stream at Cierva Point, Antarctic Peninsula
Authors: MATALONI GABRIELA , VINOCUR ALICIA , de TEZANOS PINTO PAULA
Published: June 2005

Pingüinera Stream is one of the two main lotic environments of Cierva Point (Antarctic Specially Protected Area No. 134) on the Danco Coast, Antarctic Peninsula. It originates in a large snowfield, flows through a penguin rookery, moss and grass banks, discharging into Cierva Cove. During late Antarctic summer 2003, we sampled the stream at six locations along its course. Abiotic features characterize it as a clear water system, yet receiving a very high amount of PO4-P and NH4-N from the rookery. These nutrients decrease downstream mainly due to uptake by epilithic algae and oxidation of NH4+ to NO3-, consequently lowering pH and dissolved O2, which was always under-saturated. Strong correlations between all these parameters support these findings. The epilithic algal community shows both temporal and spatial changes in biomass, composition and relative frequencies. Dominant species at the higher reach of the stream are cyanobacteria, mainly Chamaesiphon subglobosus (Rostafinski) Lemm. and a mesh of Leptolyngbya spp. filaments. The chlorophyta Prasiola calophylla (Carmich.) Menegh. dominates the community in oxygenated, fast-flowing reaches. Comparison with the other main stream from Cierva Point, which is not influenced by the rookery, shows that growth and survival of the epilithic community in this area is limited by factors other than nutrient concentrations.
Biogeochemical cycle of organic matter in a subtidal benthic environment in Marian Cove, King George Island, Antarctica
Authors: SHIM JEONGHEE , HAN MYUNG WOO , KANG YOUNG CHUL , KIM DONGSEON
Published: June 2005

The flux and composition of settling particles were measured in a subtidal benthic environment of Marian Cove, King George Island, from February 1998–January 2000. The total mass flux ranged between 2.47 g m−2 d−1 (August and September 1998) and 21.97 g m−2 d−1 (February 1999), and showed distinct seasonal variation: high in the summer and low in winter. Lithogenic particles constituted 70–95% of the total particles, while biogenic particles represented only 10%, except in spring when biogenic particles made up more than 30%. The fluxes of organic carbon, biogenic silica, nitrogen, and organic phosphorus all peaked in spring rather than in summer, with ranges of 4.4–34.0, 1.2–23.5, 0.48–5.56, and 0.01–0.15 mmol m−2 d−1, respectively. Fluxes of metals (Al, Ti, Cu, Cd, and Pb) showed temporal variability, similar to that of the total mass flux, but each metal had different enrichment factor (EF) values. The EF value of Cu correlated positively with fluxes in lithogenic components, while the EF value of Cd correlated with biogenic particle fluxes. The Cu flux is mainly related to substantial inflows of melt water laden with Cu- enriched lithogenic particles. The Cd flux is probably associated with organic matter deposition following phytoplankton blooms in the water column.
Sea ice changes inferred from methanesulphonic acid (MSA) variation in East Antarctic ice cores: are krill responsible?
Authors: KAWAGUCHI SO , KASAMATSU NOBUE , WATANABE SHUICHI , ODATE TSUNEO , FUKUCHI MITSUO , NICOL STEPHEN
Published: June 2005

Dimethyl sulphide (DMS) and its oxidation products (e.g. methanesulphonic acid, MSA) are known to play important roles in atmospheric chemistry (Liss et al. 1997). They act as source of atmospheric particles, and affect the radiative balance of the atmosphere directly by absorbing and scattering solar radiation or indirectly by forming cloud condensation nuclei, which enhance cloud albedo (Charlson et al. 1987, Curran & Jones 2000).
Upper crustal structure of Deception Island area (Bransfield Strait, Antarctica) from gravity and magnetic modelling
Authors: MUÑOZ-MARTÍN A. , CATALÁN M. , MARTÍN-DÁVILA J. , CARBÓ A.
Published: June 2005

Deception Island is a young, active volcano located in the south-western part of Bransfield Strait, between the Antarctic Peninsula and the South Shetland archipelago. New gravity and magnetic data, from a marine geophysical cruise (DECVOL-99), were analysed. Forty-eight survey lines were processed and mapped around Deception Island to obtain Bouguer and magnetic anomaly maps. These maps show well- defined groups of gravity and magnetic anomalies, as well as their gradients. To constrain the upper crustal structure, we have performed 2+1/2D forward modelling on three profiles perpendicular to the main anomalies of the area, and taking into account previously published seismic information. From the gravity and magnetic models, two types of crust were identified. These were interpreted as continental crust (located north of Deception Island) and more basic crust (south of Deception Island). The transition between these crustal types is evident in the Bouguer anomaly map as a high gradient area trending NE–SW. Both magnetic and gravity data show a wide minimum at the eastern part of Deception Island, which suggests a very low bulk susceptibility and low density intrusive body. With historical recorded eruptions and thermal and fumarolic fields, we interpret this anomaly as a partially melted intrusive body. Its top has been estimated to be at 1.7 km depth using Euler deconvolution techniques.
Cenozoic glaciogenic sedimentary record in the Grove Mountains of East Antarctica
Authors: FANG AIMIN , LIU XIAOHAN , LI XIAOLI , HUANG FEIXIN , YU LIANGJUN
Published: June 2005

During fieldwork of the 1998–99 and 1999–2000 Chinese National Antarctic Research Expedition (CHINARE), three different kinds of Cenozoic sedimentary record were found in the Grove Mountains, which are in East Antarctica about 450km inland of Prydz Bay. These consist of (1) glaciogenic sedimentary erratics found in the moraine banks in the central area of Grove Mountains, which can be subdivided into four types according to different degrees of lithification as well as differences in inner structure and include in-situ diamicts; (2) palaeosols found in several small depressions in the southern slope of the Mount Harding; and (3) different kinds of glacial moraine floating on the surface of blue ice or around the foot of some nunataks. Preliminary results suggest that the in situ glaciogenic sediments were formed in the ice-sheet frontal area by the interaction of glacial movement and ice sheet melt water under climatic conditions warmer than today.
The Permian–Triassic boundary in Antarctica
Authors: RETALLACK G.J. , JAHREN A.H. , SHELDON N.D. , CHAKRABARTI R. , METZGER C.A. , SMITH R.M.H.
Published: June 2005

The Permian ended with the largest of known mass extinctions in the history of life. This signal event has been difficult to recognize in Antarctic non-marine rocks, because the boundary with the Triassic is defined by marine fossils at a stratotype section in China. Late Permian leaves (Glossopteris) and roots Vertebraria), and Early Triassic leaves (Dicroidium) and vertebrates (Lystrosaurus) roughly constrain the Permian–Triassic boundary in Antarctica. Here we locate the boundary in Antarctica more precisely using carbon isotope chemostratigraphy and total organic carbon analyses in six measured sections from Allan Hills, Shapeless Mountain, Mount Crean, Portal Mountain, Coalsack Bluff and Graphite Peak. Palaeosols and root traces also are useful for recognizing the Permian–Triassic boundary because there was a complete turnover in terrestrial ecosystems and their soils. A distinctive kind of palaeosol with berthierine nodules, the Dolores pedotype, is restricted to Early Triassic rocks. Late Permian and Middle Triassic root traces are carbonaceous, whereas those of the Early Triassic are replaced by claystone or silica. Antarctic Permian–Triassic sequences are among the most complete known, judging from the fine structure and correlation of carbon isotope anomalies.
Major eruption-induced changes to the McDonald Islands, southern Indian Ocean
Authors: STEPHENSON JON , BUDD G.M. , MANNING J. , HANSBRO P.
Published: June 2005

The McDonald Islands (53°S, 73°E) originally comprised three small islands that lie on the Kerguelen Plateau, 44 km west of Heard Island. No volcanic activity was observed since their discovery in 1874 until 1997, when two passing ships recorded major changes and eruptive behaviour. A 2001 satellite image showed that the main island had doubled its area. This paper reports observations made from a cruise ship in November 2002, supplemented by a high-resolution satellite image acquired in March 2003. A new volcanic complex comprises lava domes, spines and flows, all assumed to be phonolitic, similar to the older volcanic rocks. The complex shows dormant volcanic activity, with numerous fumaroles, recent spine evolution and lava flows. Changes in relative sea level have connected Flat and McDonald Islands. A spit about 1km long with extensive shoals beyond, now extends eastward from McDonald Island and presents new hazards to shipping. Biological changes include colonization by king penguins (Aptenodytes patagonica), previously absent, and a large reduction in numbers of formerly widespread macaroni penguins (Eudyptes chrysolophus chrysolophus).
Nautilids from the Upper Cretaceous of the James Ross Basin, Antarctic Peninsula
Authors: CICHOWOLSKI MARCELA , AMBROSIO ALFREDO , CONCHEYRO ANDREA
Published: June 2005

To date, Cretaceous nautilids from the Antarctic Peninsula have received little attention and only a single species had been reported, Eutrephoceras simile Spath, from Seymour, Snow Hill, and James Ross islands. Currently, it is considered a synonym of Eutrephoceras subplicatum (Steinmann), which has also been described from the Upper Cretaceous of central Chile, southern Argentina and Angola. Here, we report and describe E. subplicatum in detail, based on specimens from the Lower Campanian–Maastrichtian of Vega, Seymour and James Ross islands, presenting, for the first time, embryonic conch features related to the palaeoecology of these organisms. The nauta of this species had a diameter of approximately 30 mm with 5–6 septa. In addition, we describe a new species, Eutrephoceras antarcticum, and one specimen assigned to the same genus in open nomenclature, both recovered from the Lower Campanian beds of James Ross Island.
Exploring Antarctica - a centennial perspective
Authors: WALTON DAVID
Published: June 2005

We are embarked on a decade of celebrations of the national expeditions of what is now termed the Heroic Age. Exploring the Antarctic – the great unknown continent – a hundred years ago was great adventure and, given what we now know of the primitive state of their equipment, it is surprising that more of these explorers did not die. The tragic death of Captain Scott's polar party must be taken as a key talisman for the title “Heroic Age” but we should not underestimate the courage and fortitude of all the others – British, Swedish, Norwegian, French, German, Belgian, Argentinean, Polish, Romanian, American etc – who sailed, walked and sledged into the unknown for the greater good of their nation.