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2.
R Soc Open Sci ; 8(2): 201686, 2021 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-33972861

RESUMEN

The diverse living Australian lizard fauna contrasts greatly with their limited Oligo-Miocene fossil record. New Oligo-Miocene fossil vertebrates from the Namba Formation (south of Lake Frome, South Australia) were uncovered from multiple expeditions from 2007 to 2018. Abundant disarticulated material of small vertebrates was concentrated in shallow lenses along the palaeolake edges, now exposed on the western of Lake Pinpa also known from Billeroo Creek 2 km northeast. The fossiliferous lens within the Namba Formation hosting the abundant aquatic (such as fish, platypus Obdurodon and waterfowl) and diverse terrestrial (such as possums, dasyuromorphs and scincids) vertebrates and is hereafter recognized as the Fish Lens. The stratigraphic provenance of these deposits in relation to prior finds in the area is also established. A new egerniine scincid taxon Proegernia mikebulli sp. nov. described herein, is based on a near-complete reconstructed mandible, maxilla, premaxilla and pterygoid. Postcranial scincid elements were also recovered with this material, but could not yet be confidently associated with P. mikebulli. This new taxon is recovered as the sister species to P. palankarinnensis, in a tip-dated total-evidence phylogenetic analysis, where both are recovered as stem Australian egerniines. These taxa also help pinpoint the timing of the arrival of scincids to Australia, with egerniines the first radiation to reach the continent.

4.
Proc Natl Acad Sci U S A ; 106(49): 20646-51, 2009 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-19923428

RESUMEN

The ratite moa (Aves: Dinornithiformes) were a speciose group of massive graviportal avian herbivores that dominated the New Zealand (NZ) ecosystem until their extinction approximately 600 years ago. The phylogeny and evolutionary history of this morphologically diverse order has remained controversial since their initial description in 1839. We synthesize mitochondrial phylogenetic information from 263 subfossil moa specimens from across NZ with morphological, ecological, and new geological data to create the first comprehensive phylogeny, taxonomy, and evolutionary timeframe for all of the species of an extinct order. We also present an important new geological/paleogeographical model of late Cenozoic NZ, which suggests that terrestrial biota on the North and South Island landmasses were isolated for most of the past 20-30 Ma. The data reveal that the patterns of genetic diversity within and between different moa clades reflect a complex history following a major marine transgression in the Oligocene, affected by marine barriers, tectonic activity, and glacial cycles. Surprisingly, the remarkable morphological radiation of moa appears to have occurred much more recently than previous early Miocene (ca. 15 Ma) estimates, and was coincident with the accelerated uplift of the Southern Alps just ca. 5-8.5 Ma. Together with recent fossil evidence, these data suggest that the recent evolutionary history of nearly all of the iconic NZ terrestrial biota occurred principally on just the South Island.


Asunto(s)
Evolución Biológica , Extinción Biológica , Geografía , Paleognatos/genética , Paleontología , Animales , Biodiversidad , Calibración , ADN Mitocondrial/genética , Especiación Genética , Datos de Secuencia Molecular , Nueva Zelanda , Paleognatos/clasificación , Filogenia , Factores de Tiempo
5.
Calcif Tissue Int ; 81(1): 10-7, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17520163

RESUMEN

The murine arachidonate 15-lipoxygenase gene (Alox15) has recently been identified as a negative regulator of peak bone mineral density (BMD). The human ALOX15 gene shares significant sequence homology with the murine Alox15 gene; however, the human arachidonate 12-lipoxygenase gene (ALOX12) is functionally more similar to the mouse gene. Multiple single-nucleotide polymorphisms (SNPs) in the human ALOX15 and ALOX12 genes have previously been reported to be significantly associated with BMD in humans. On the basis of these data, we carried out our own investigation of the human ALOX15 and ALOX12 genes and their relationship with hip and spine BMD parameters. The study population consisted of 779 postmenopausal women with a mean (+/- standard deviation) age of 62.5 +/- 5.9 years at BMD measurement and was recruited from a single large general practice in Chingford, northeast London. Three SNPs from ALOX15 and five from ALOX12 were analyzed. None of the SNPs that we analyzed in ALOX15 were significantly associated with any of the BMD parameters or fracture data. However, we found that three SNPs from ALOX12, all previously associated with spine BMD in women, were significantly associated with spine and various hip BMD parameters in our cohort (P = 0.029-0.049). In conclusion, we found no association between polymorphism in ALOX15 and BMD phenotypes but were able to replicate previous findings that genetic variation in ALOX12 seems to play a role in determining bone structure in Caucasian women.


Asunto(s)
Araquidonato 12-Lipooxigenasa/genética , Araquidonato 15-Lipooxigenasa/genética , Densidad Ósea , Estudios de Cohortes , Densitometría , Femenino , Fracturas Óseas , Haplotipos , Cadera/patología , Humanos , Desequilibrio de Ligamiento , Osteoporosis , Posmenopausia , Columna Vertebral/patología , Población Blanca
6.
Trends Ecol Evol ; 8(12): 433-7, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21236223

RESUMEN

It is 150 years since Sir Richard Owen announced the former existence of large flightless ostrich-like birds in New Zealand based on a fragment of femur presented to him in England. Numerous studies of this extinct group of giant birds, now known by the Polynesian (plural) name 'moa', have provided much information about their effects on the flora, their recent extinction, and the evolutionary history of New Zealand and its endemic biota. Significant revision of moa taxonomy and ecology continues, and recent molecular phylogenetic analyses have stimulated new hypotheses about moa evolution.

7.
J Anal Toxicol ; 9(1): 1-5, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-2984463

RESUMEN

A non-invasive saliva sample delta 9-THC radioimmunoassay has been applied to 352 samples from 25 male and 10 female marijuana users after administration of one-half to two standard cigarettes (27 mg delta 9-THC/cigarette) and 72 control negative subjects who ingested a large variety of foods, condiments, or medications in an attempt to demonstrate interferences. The shortest duration of a positive was 2 hrs and the longest was 5 hrs after administration of the cannabis. No positives occurred in control subjects.


Asunto(s)
Dronabinol/análisis , Abuso de Marihuana , Radioinmunoensayo/métodos , Saliva/análisis , Adulto , Femenino , Humanos , Masculino
8.
Clin Radiol ; 35(6): 447-9, 1984 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6499381

RESUMEN

Thirty-five patients with Hodgkin's disease were staged with the aid of chest radiographs, bipedal lymphograms and computed tomography (CT) scans. Computed tomographic findings altered management in only two patients (6%) by indicating enlargement of their radiotherapy fields. After lymphography, five patients (14%) were changed from Stage II (clinical and CT staging) to Stage III, so altering their management. Because either technique may show more extensive disease, CT and lymphography are complementary. Computed tomography should be performed initially. If it reveals no abnormality in the lymphogram area, lymphography, too, should be undertaken. Inverted Y fields are easier to visualise and design from lymphograms than from CT sections.


Asunto(s)
Enfermedad de Hodgkin/diagnóstico por imagen , Linfografía , Tomografía Computarizada por Rayos X , Terapia Combinada , Enfermedad de Hodgkin/patología , Enfermedad de Hodgkin/terapia , Humanos , Laparotomía , Estadificación de Neoplasias , Radiografía Torácica
11.
Somatic Cell Genet ; 4(3): 265-98, 1978 May.
Artículo en Inglés | MEDLINE | ID: mdl-694721

RESUMEN

Acetylcholinesterase (AchE) is reported to have a narrowly restricted distribution among human tissues. Three strains of human fibroblasts which are trisomic for chromosome 2 had an average level of AchE activity over 28 times higher than the average level in 19 control strains of human fibroblasts. In contrast, the mean pseudocholinesterase activity of the trisomy-2 strains did not differ appreciably, or significantly, from the mean for the control strains. The 19 control strains included 10 strains trisomic for autosomes other than 2, and 9 euploid strains. Our estimate of the mean AchE activity in the control strains did not differ significantly from zero and might, in any case, have originated from a minute amount of activity contributed to the cells by an esterase in our culture medium. Despite the striking elevation of AchE activity in fibroblasts trisomic for chromosome 2, extracts of these cells had only about 1.5% of the specific AchE activity (per microgram DNA) present in extracts of human cerebral cortex. None of the 22 strains studied had detectable activity for two other enzymes which, like AchE, have a restricted distribution among human tissues: xanthine oxidase and choline acetyltransferase.


Asunto(s)
Acetilcolinesterasa/genética , Cromosomas Humanos 1-3 , Genes , Trisomía , Alelos , Encéfalo/enzimología , Butirilcolinesterasa/genética , Células Cultivadas , Colina O-Acetiltransferasa/genética , Mapeo Cromosómico , Fibroblastos , Humanos , Xantina Oxidasa/genética
12.
Recent Results Cancer Res ; 64: 180-9, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-366696

RESUMEN

Vertical studies indicate that, in general, acute phase reactant proteins (APRP) reflect disease activity in both Hodgkin's disease and non-Hodgkin's lymphoma. Longitudinal studies of the selected APRP profile demonstrate the following: 1. The stable profile is characteristic of remission. 2. Considerable elevation of APRPs coincides with relapsed disease. 3. An unstable profile is a feature of relapsing disease and may give early warning of relapse. 4. Patients responding inadequately to treatment frequently have unstable APRP profiles.


Asunto(s)
Enfermedad de Hodgkin/sangre , Linfoma/sangre , Adulto , Proteína C-Reactiva/análisis , Quimotripsina/antagonistas & inhibidores , Femenino , Glicoproteínas/sangre , Humanos , Linfoma de Células B Grandes Difuso/sangre , Linfoma no Hodgkin/sangre , Masculino , Persona de Mediana Edad , Orosomucoide/análisis , alfa 1-Antitripsina/análisis
14.
Mol Gen Genet ; 138(3): 179-92, 1975 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-1102927

RESUMEN

The properties of minicell producing mutants of Escherichia coli deficient in gentic recombination were examined. Experiments were designed to test recombinant formation in conjugal crosses, survival following UV-irradiation in cells, and the state of DNA metabolism in minicells. The REC- phenotypes are unaffected by min+/- genotypes in whole cells. In contrast to minicells produced by rec+ parental cells, minicells from a recB21 strain have limited capacity to degrade linear, Hfr transfereed DNA. The lack of a functional recA gene product, presumably involved in inhibiting the recBC nuclease action(s), permits unrestricted Hfr DNA breakdown in minicells produced by a recA1 strain. This results in an increase in TCA soluble products and in the formation of small DNA molecules that sediment near the top of an alkaline sucrose gradient. Unlike the linear DNA, circular duplex DNA from plasmids R 64-11 or lambdadv, segregated into the minicells, is resistant to breakdown. By using in vitro criteria, and [32P]-labelled linear DNA from bacteriophage T7 for substrate, we found that the ATP-dependent exonuclease of the recBC complex (exo V) is present in rec+ and recA- minicells, and is lacking in the recB21 mutant. In fact, the absence of a functional exo V in recBC- minicells results in isolation of larger than average Hfr DNA from minicells. We suggest that recombination (REC) enzymes segregate into the polar minicells at the time of minicell biogenesis. This system should be useful for studies on DNA metabolism and functions of the recBC and recA gene products.


Asunto(s)
ADN Bacteriano/metabolismo , Escherichia coli , Exonucleasas/análisis , Mutación , Recombinación Genética , ADN Bacteriano/efectos de la radiación , Mitosis , Genética de Radiación , Rayos Ultravioleta
16.
Proc Natl Acad Sci U S A ; 71(8): 3031-5, 1974 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-4528586

RESUMEN

Orotic aciduria is a rare autosomal recessive disease in man due to a deficiency of orotate phosphoribosyltransferase (EC 2.4.2.10; orotidine-5'-phosphate:pyrophosphate phosphoribosyltransferase) and orotidine-5'-phosphate decarboxylase (EC 4.1.1.23; orotidine-5'-phosphate carboxy-lyase). We have compared certain physicochemical properties of orotidine-5'-phosphate decarboxylase from normal and mutant fibroblasts grown under identical conditions. Orotidine-5'-phosphate decarboxylase from homozygous mutant cells was more thermolabile and exhibited a different electrophoretic mobility when compared to the enzyme from normal cells; orotidine-5'-phosphate decarboxylase from one heterozygous cell strain exhibited an intermediate thermolability while the other heterozygote displayed a thermal inactivation curve indistinguishable from normal. The enzyme from both normal and mutant cells exhibited biphasic kinetics with the same apparent Michaelis constants. These data suggest that the molecular defect in the enzyme of this patient with orotic aciduria is due to a mutation in a gene that affects the structure of either orotate phosphoribosyltransferase or orotidine-5'-phosphate decarboxylase and cannot be attributed to a mutation in a regulatory gene, as previously suggested.


Asunto(s)
Carboxiliasas/deficiencia , Genes , Mutación , Ácido Orótico/orina , Pentosiltransferasa/deficiencia , Errores Innatos del Metabolismo de la Purina-Pirimidina/genética , Azauridina/farmacología , Radioisótopos de Carbono , Carboxiliasas/metabolismo , Células Cultivadas , Centrifugación por Gradiente de Densidad , Electroforesis en Gel de Poliacrilamida , Femenino , Fibroblastos/enzimología , Genes Reguladores , Calor , Humanos , Masculino , Ácido Orótico/metabolismo , Pentosiltransferasa/metabolismo , Errores Innatos del Metabolismo de la Purina-Pirimidina/enzimología , Errores Innatos del Metabolismo de la Purina-Pirimidina/orina , Estimulación Química
18.
J Bacteriol ; 115(2): 498-505, 1973 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-4269375

RESUMEN

The excision of pyrimidine dimers from the deoxyribonucleic acid (DNA) of Neurospora crassa was examined. Postirradiation incubation in the presence of several chemicals known to inhibit various repair systems indicated that caffeine reduced the rate of excision twofold, but did not inhibit excision completely as did proflavine and quinacrine. Examination of the time course of excision showed that repair occurs at a relatively rapid rate: approximately 60 dimers excised per min after 500 ergs/mm(2). Further evidence for rapid excision was obtained by sedimentation analysis of DNA; the maximal number of breaks introduced during repair was three, suggesting that breaks are repaired almost as fast as they are made and that only a few dimers are repaired at a time. Repair synthesis was measured by prelabeling the DNA with (15)N and D(2)O, and then subjecting the DNA to equilibrium density gradient centrifugation after postirradiation incubation with (32)P. Accumulation of single-strand breaks with increasing dose of ultraviolet radiation suggested that the limiting step was subsequent to the incision and excision steps of repair. Equilibrium CsCl centrifugation demonstrated that the limiting step in excision was repair synthesis.


Asunto(s)
ADN/biosíntesis , Neurospora/metabolismo , Acridinas/farmacología , Cafeína/farmacología , Centrifugación por Gradiente de Densidad , ADN/análisis , ADN/aislamiento & purificación , Reparación del ADN/efectos de los fármacos , ADN de Cadena Simple/análisis , Deuterio , Desinfectantes/farmacología , Peso Molecular , Neurospora crassa/análisis , Neurospora crassa/metabolismo , Neurospora crassa/efectos de la radiación , Isótopos de Nitrógeno , Isótopos de Fósforo , Quinacrina/farmacología , Efectos de la Radiación , Rayos Ultravioleta
19.
J Bacteriol ; 110(3): 1010-6, 1972 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-4260557

RESUMEN

A method is described for labeling a specific pyrimidine in the deoxyribonucleic acid (DNA) of Neurospora crassa. In cells grown in the presence of [5-(3)H]-uridine, more than 97% of the radioactivity associated with the DNA had been incorporated into cytosine. The specific activity of the labeled DNA was approximately 3 x 10(3) counts per min per mug. The DNA was isolated by elution from hydroxyapatite columns with sodium phosphate buffer (0.40 m, pH 6.8). This procedure was used to demonstrate that in vegetative cells of N. crassa both photoreactivation and excision repair are operative, as measured by the removal of ultraviolet light-induced cytosine-containing dimers.


Asunto(s)
ADN/biosíntesis , Neurospora/metabolismo , Rayos Ultravioleta , Isótopos de Carbono , Cromatografía por Intercambio Iónico , Citosina/biosíntesis , ADN/aislamiento & purificación , ADN/efectos de la radiación , Reparación del ADN , Hidroxiapatitas , Neurospora crassa/metabolismo , Neurospora crassa/efectos de la radiación , Estimulación Luminosa , ARN/biosíntesis , Efectos de la Radiación , Tritio , Uridina/metabolismo
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