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Biomedical subjects

E Roeder

Publications and source records attributed to E Roeder.

At least 19 recordsLinked to original sources
PubMed2003

Neuroprotective effects of hydroxysafflor yellow A: in vivo and in vitro studies.

Previous work has shown that hydroxysafflor yellow A (HSYA), extracted from Carthamus tinctorius L. markedly extended the coagulation time in mice and exhibited a significant antithrombotic effect in rats. The present study was conducted to demonstrate further its neuroprotective effects on cerebral ischemic injury in both in vivo and in vitro studies. In vivo, male Wistar-Kyoto (WKY) rats with middle cerebral artery occlusion (MCAO) were evaluated for neurological deficit scores followed by the treatment with a single dose of HSYA. Furthermore, the infarction area of the brain was assessed in the brain slices. In vitro, the effect of HSYA was tested in cultured fetal cortical cells exposed to glutamate and sodium cyanide (NaCN) to identify its neuroprotection against neurons damage. The results in vivo showed that sublingular vein injection of HSYA at doses of 3.0 mg/kg and 6.0 mg/kg exerted significant neuroprotective effects on rats with focal cerebral ischemic injury by significantly decreasing neurological deficit scores and reducing the infarct area compared with the saline group, HSYA at a dose of 6.0 mg/kg showed a similar potency as nimodipine at a dose of 0.2 mg/kg. Sublingular vein injection of HSYA at the dose of 1.5 mg/kg showed a neuroprotective effect, however, with no significant difference when compared with the saline group. Results in vitro showed that HSYA significantly inhibited neuron damage induced by exposure to glutamate and sodium cyanide (NaCN) in cultured fetal cortical cells. Noticeably, the neuroprotective action of HSYA on glutamate-mediated neuron injury was much better than that of HSYA on NaCN-induced neuron damage. All these findings suggest that HSYA might act as a potential neuroprotective agent useful in the treatment in focal cerebral ischemia. Abbreviations. HSYA:hydroxysafflor yellow A TTC:2,3,5-triphenyltetrazolium chloride MTT:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide DMEM:Dulbecco's modified Eagle medium FCS:Fetal calf serum MCAO:middle cerebral artery occlusion ECA:external carotid artery ICA:internal carotid artery LDH:lactate dehydrogenase NMDA: N-methyl- D-aspartate

Animals↗
PubMed2000

Trisomy 12 mosaicism confirmed in multiple organs from a liveborn child.

This patient, in whom trisomy 12 mosaicism was confirmed in multiple organs, is the fifth case diagnosed postnatally and the first reported for whom a meiotic origin of the trisomy, maternal meiosis I, was determined. Mosaic aneuploidy was suspected because of pigmentary dysplasia, a frequent but non-specific finding in chromosomal mosaicism. The severe phenotype of this child, who died in infancy with a complex heart malformation, was probably a result of the high percentage of trisomic cells. Cytogenetic and interphase fluorescent in situ hybridization analyses showed a highly variable distribution of aneuploid cells in the nine tissues studied, from none in blood and ovary to 100% in spleen and liver. The trisomy arose meiotically with apparent post-zygotic loss of one of the chromosomes 12; uniparental disomy for this chromosome in the diploid cell line was excluded. The phenotype of the cases reported in living or liveborn individuals has been extremely variable, ranging from the present case, in which the child died in infancy with multiple malformations and pigmentary dysplasia, to a fortuitous finding in an adult studied for infertility. The variation in severity is probably determined by the proportion and distribution of the trisomic cells, which is linked to the timing of the non-disjunctional error.

Abnormalities, Multiple↗
PubMed2000

Fronto-otopalatodigital osteodysplasia: clinical evidence for a single entity encompassing Melnick-Needles syndrome, otopalatodigital syndrome types 1 and 2, and frontometaphyseal dysplasia.

Otopalatodigital syndrome type 2 is an X-linked disorder with minimal expression in carrier females and comprises typical facial anomalies and a generalized bone dysplasia with osteodysplastic changes, brachydactyly, and impaired survival. Recently several other severe malformations were reported in the condition. Melnick-Needles syndrome is an X-linked dominant disorder. Affected males are usually sporadic cases. The exceptional males born to symptomatic women present with a lethal disorder comprising generalized osteodysplasia, deficiency of the first ray, and facial anomalies strikingly similar to those of otopalatodigital syndrome type 2. We report here on three boys with classical, severe, and lethal otopalatodigital type 2 syndrome, and three boys with severe (lethal) Melnick-Needles syndrome, born to affected mothers. We suggest that otopalatodigital type 1 and 2, Melnick-Needles syndrome and frontometaphyseal dysplasia, sharing many clinical manifestations and a similar mode of inheritance, are variants of the same condition: fronto-otopalatodigital osteodysplasia. The relationships to similar syndromes (i.e., Saint-Martin-Gardner-Morrisson syndrome, serpentine fibula syndrome, atelosteogenesis type 3, boomerang dysplasia, and Yunis-Varon syndrome) are discussed.

Abnormalities, Multiple↗
PubMed2000

Medicinal plants in China containing pyrrolizidine alkaloids.

Medicinal plants and remedies are widely used for various ailments throughout the world. Many of these plants contain pyrrolizidine alkaloids (PAs) which are hepatotoxic, pneumotoxic, genotoxic, neurotoxic, and cytotoxic. As a result of their use in Traditional Chinese Medicine (TCM), medicinal plants are becoming increasingly important not only in China but also in many other countries. This paper will therefore give, a critical overview of PA-containing plants belonging mainly to the families Boraginaceae, Leguminosae (Tribus Crotalarieae), and Asteraceae (Tribus Senecioneae and Eupatorieae). The PAs contained in the 38 plants described here differ widely in their structure and toxicity. Their metabolism and the resulting toxicity will be discussed, the dehydroalkaloids (DHAlk) produced in the liver playing a key role in cases of intoxications.

Animals↗
PubMed1999

Apparent cyclophosphamide (cytoxan) embryopathy: a distinct phenotype?

Cyclophosphamide (CP) is an alkylating agent widely used in treating cancer and autoimmune disease. CP is classified as a pregnancy risk factor D drug and is teratogenic in animals, but population studies have not conclusively demonstrated teratogenicity in humans. Six isolated reports of prenatally exposed infants with various congenital anomalies exist, but to date no specific phenotype has been delineated. The purpose of this report is to document a new case of in utero CP exposure with multiple congenital anomalies and to establish an apparent CP embryopathy phenotype. The mother had systemic lupus erythematosus and cyclophosphamide exposure in the first trimester. She also took nifedipine, atenolol, clonidine, prednisone, aspirin, and potassium chloride throughout pregnancy. The infant had growth retardation and multiple anomalies including microbrachycephaly, coronal craniosynostosis, hypotelorism, shallow orbits, proptosis, blepharophimosis, small, abnormal ears, unilateral preauricular pit, broad, flat nasal bridge, microstomia, high-arched palate, micrognathia, preaxial upper limb and postaxial lower limb defects consisting of hypoplastic thumbs, and bilateral absence of the 4th and 5th toes. Chromosomes were apparently normal. The reported cases of in utero exposure to cyclosposphamide shared the following manifestations with our patient: growth deficiency, developmental delay, craniosynostosis, blepharophimosis, flat nasal bridge, abnormal ears, and distal limb defects including hypoplastic thumbs and oligodactyly. We conclude that (a) cyclophosphamide is a human teratogen, (b) a distinct phenotype exists, and (c) the safety of CP in pregnancy is in serious question.

Abnormalities, Multiple↗
PubMed1999

Familial paragangliomas: the emerging impact of molecular genetics on evaluation and management.

HYPOTHESIS: Advancements in molecular genetics has direct impact on the evaluation and management of patients and family members with familial paragangliomas (FP). BACKGROUND: Familial paragangliomas. in contrast to sporadic cases, are commonly multiple, bilateral, and present at an earlier age. Familial tumors are inherited in an autosomal dominant pattern with genomic imprinting of the paternal allele. Mapping studies have identified regions on chromosome 11q as harboring the genetic defect responsible for paraganglioma formation. METHODS: A multigenerational family with five affected females with head and neck paragangliomas underwent clinical and genetic evaluation. Genetic mapping was performed with microsatellite markers froin chromosome 11q13 and q23. Nonaffected individuals were screened for carrying the affected haplotype. In addition, by using DNA obtained from an amniotic fluid sample. in utero screening of a fetus was performed. RESULTS: The most common complaints were hearing loss and neck masses that usually manifested by age 25. Genetic mapping identified loci 11q13 and q23 as sites likely responsible for tumorogenesis. Three unaffected family members, including a fetus, were identified as carriers of the affected haplotype. The genetic findings were used to design a screening protocol for family members at risk for developing glomus tumors. CONCLUSIONS: Genetic screening of unaffected family members can identify individuals harboring the mutated allele. Identification of family members at risk for developing FP by molecular genetic techniques may lead to early detection of head and neck paragangliomas and may directly impact morbidity from glomus tumors and their treatment.

Adult↗
PubMed1998

Pyrrolizidine alkaloids from Senecio nevadensis.

Two toxic pyrrolizidine alkaloids were isolated from Senecio nevadensis and their structures determined by spectroscopic methods. For the first time, a very complete structural assignment of all spectral data of alkaloid usaramine is given.

Magnetic Resonance Spectroscopy↗
PubMed1997

Ritscher-Schinzel (3C) syndrome: documentation of the phenotype.

Ritscher-Schinzel syndrome or 3C (craniocerebello-cardiac) syndrome is characterized by cardiac defects, cerebellar vermis hypoplasia, and cranial defects. Nineteen cases were reported previously; however, the full spectrum of this disorder has not been determined. We have evaluated two unrelated males with this condition. Both had defects of the endocardial cushion and vermis hypoplasia with hypotonia. In addition, both had hypospadias, a previously undescribed finding of this disorders. Review of the previously reported cases and those described herein demonstrate: 1) Although varying degrees of vermis hypoplasia are accompanied by hypotonia, delayed gross motor function improves with advancing age leaving speech delay as the major neurodevelopmental handicap. 2) Two different types of cardiac anomalies occur: defects of the endocardial cushion ranging from anomalies of the mitral or tricuspid valves to complete AV canal, and/or conotruncal defects. 3) Postnatal growth deficiency was seen in most patients in whom longitudinal information was available. In our review of patients with vermis hypoplasia we ascertained a patient diagnosed as having "Joubert syndrome" who had most findings of the Ritscher-Schinzel syndrome and several other patients with "Dandy-Walker syndrome" who likely have had Ritscher-Schinzel syndrome, suggesting that Ritscher-Schinzel syndrome is more common than has been appreciated. Careful search for the subtle facial changes characteristic of this disorder as well as coloboma, cleft palate/bifid uvula, short neck, syndactyly, and hypoplasia of the nails is warranted when evaluating children with Dandy-Walker malformation with or without clinical signs of Joubert syndrome.

Abnormalities, Multiple↗
PubMed1996

New pentapeptides from Aster tataricus.

Three pentapeptides have been isolated from the roots of Aster tataricus and their structures elucidated on the basis of spectroscopic analysis as well as chemical and enzymatic methods.

Amino Acid Sequence↗
PubMed1996

Pentapeptides from the roots of Aster tataricus.

Asterinin D and E, pentapeptides, have been isolated from the roots of Aster tataricus L.f. (Compositae, syn. Asteraceae, subtribe Asteroideae) and their structures have been elucidated on the basis of spectroscopic analysis, as well as chemical and enzymatic methods.

Amino Acid Sequence↗
PubMed1995

Effect of myotonic dystrophy trinucleotide repeat expansion on DMPK transcription and processing.

The myotonic dystrophy (DM) mutation has been identified as an unstable, expanded (CTG)n repeat in the 3' untranslated region of a gene designated DM protein kinase (DMPK). Both decreased and increased levels of mutant DMPK mRNA as well as decreased levels of protein have been variously reported and invoked to explain disparate molecular bases of this dominantly inherited disease. Most recently, increased nucleosome binding to such expanded repeats has been interpreted as support for transcriptional repression. A quantitative allele-specific RT-PCR procedure was developed and applied to a spectrum of patient tissue samples and cell lines. Equal levels of unprocessed pre-mRNA were produced by the wildtype (+) and disease (DM) alleles in skeletal muscle and cell lines of heterozygous DM patients. Thus, any increased nucleosome binding had no effect at the level of transcriptional initiation and transcription of the mutant DMPK locus. In contrast, processed mRNA levels from the DM allele were reduced relative to the+allele as the size of the expansion increased. The unstable repeat, therefore, impairs post-transcriptional processing of DM allele transcripts. This phenomenon has profound effects on overall DMPK locus steady-state transcript levels in cells missing a wildtype allele and does not appear to be mediated by imprinting, decreased mRNA stability, generation of aberrant splice forms, or absence of polyadenylation of the mutant allele.

Adolescent↗
PubMed1995

Analysis of pyrrolizidine alkaloids: a competitive enzyme-linked immunoassay (ELISA) for the quantitative determination of some toxic pyrrolizidine alkaloids.

A highly sensitive and specific competitive enzyme-linked immunoassay (ELISA) for the determination of retrorsine, senecionine, and integerrimine in the nanogram range has been developed. Pyrrolizidine alkaloids were detected in Senecio rupestris. No cross-reactivity was seen with either retrosine N-oxide, otonecine alkaloids, or other macrocyclic pyrrolizidine alkaloids.

Animals↗
PubMed1994

Diterpene glycosides from Iphiona aucheri.

Iphiona aucheri is responsible for poisoning racing camels (Camelus dromedarius) in the United Arab Emirates U. A. E. Terpenoids, a non-toxic pyrrolizidine alkaloid and two diterpene glycosides, atractyloside and carboxyatractyloside, were isolated and their structures determined by spectroscopic methods. Atractyloside and carboxyatractyloside were identified as the toxic principle of the plant.

Animals↗
PubMed1994

Differing embryotoxic effects of senecionine and senecionine-N-oxide on the chick embryo.

The embryotoxic properties of pyrrolizidine alkaloids senecionine (water insoluble) and senecionine-N-oxide (water soluble) were examined using the CHEST method (Chick Embryotoxicity Screening Test). The beginning of the embryotoxicity range for senecionine was found to be between 3-30 micrograms; senecionine-N-oxide, on the other hand, showed no effect even with 100 micrograms dose. On the basis of the theoretical calculation, it can be expected that senecionine embryotoxicity for mammals ranges between 10-100 mg/kg maternal body weight, overlapping in this way the known adult toxicity range. The rat LD50 of most alkaloids known to be significant for human health are in the range of 34-300 mg/kg.

Animals↗