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1.
Proc Natl Acad Sci U S A ; 108(13): 5308-12, 2011 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-21402916

RESUMO

Conservation scientists, national governments, and international conservation groups seek to devise, and implement, governance strategies that mitigate human impact on the environment. However, few studies to date have systematically investigated the performance of different systems of governance in achieving successful conservation outcomes. Here, we use a newly-developed analytic framework to conduct analyses of a suite of case studies, linking different governance strategies to standardized scores for delivering ecosystem services, achieving sustainable use of natural resources, and conserving biodiversity, at both local and international levels. Our results: (i) confirm the benefits of adaptive management; and (ii) reveal strong associations for the role of leadership. Our work provides a critical step toward implementing empirically justified governance strategies that are capable of improving the management of human-altered environments, with benefits for both biodiversity and people.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/legislação & jurisprudência , Conservação dos Recursos Naturais/métodos , Ecossistema , Governo , Animais , Humanos
2.
J Comp Neurol ; 503(1): 110-27, 2007 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-17480013

RESUMO

Because the posterior limb of the rostral suprasylvian sulcus (RSp) of the cat resides in close proximity to representations of the somatosensory, auditory, and visual modalities, the surrounding cortices would be expected to be a region where a high degree of multisensory convergence and integration is found. The present experiments tested this notion by using anatomical and electrophysiological methods. Tracer injections into somatosensory, auditory, and visual cortical areas almost all produced terminal labeling within the RSp, albeit at different locations and in different proportions. Inputs from somatosensory cortices primarily targeted the inner portion of the anterior RSp; inputs from auditory cortices generally filled the outer portion of the middle and posterior RSp; inputs from visual cortices terminated in the inner portion of the posterior RSp. These projections did not have sharp borders but often overlapped one another, thereby providing a substrate for multisensory convergence. Electrophysiological recordings confirmed this anatomical organization as well as identifying the presence of multisensory (bimodal) neurons in the areas of overlap between representations. Curiously, however, the proportion of bimodal neurons was only 24% of the neurons sampled in this region, and the majority of these did not show multisensory interactions when combined-modality stimuli were presented. In summary, these experiments indicate that the RSp is primarily auditory in nature, but this representation could be further subdivided into an outer sulcal anterior auditory field (sAAF) and an inner field of the rostral suprasylvian sulcus (FRS).


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiologia , Vias Neurais/fisiologia , Percepção/fisiologia , Animais , Gatos , Córtex Cerebral/citologia , Vias Neurais/citologia , Neurônios/citologia , Neurônios/fisiologia
3.
Am J Med Genet ; 98(1): 103-6, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11426447

RESUMO

Familial transmission of cytogenetically visible autosome deletions is rare in humans. We describe here a case of mother to son transmission of an interstitial deletion of the distal long arm of chromosome one, breakpoints q42.1q42.3. This is the smallest described deletion of this region to date.


Assuntos
Anormalidades Múltiplas/genética , Deleção Cromossômica , Cromossomos Humanos Par 1/genética , Adulto , Sintomas Comportamentais , Criança , Aberrações Cromossômicas/genética , Transtornos Cromossômicos , Anormalidades Craniofaciais/genética , Análise Citogenética , Saúde da Família , Feminino , Humanos , Transmissão Vertical de Doenças Infecciosas , Masculino , Mães , Fenótipo
5.
Biochem Mol Med ; 58(1): 18-24, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8809352

RESUMO

Defects in the G (guanine nucleotide-binding)-protein subunit (G alpha s) which stimulates adenylyl cyclase may result in either loss or gain of endocrine function. Reduced G alpha s activity is found in the hormone resistance syndrome, pseudohypoparathyroidism type Ia (PHP-Ia), while constitutive activation of G alpha s is associated with endocrine organ overactivity, including the gonadotropin-independent sexual precocity seen in patients with McCune-Albright syndrome. We identified two unrelated boys presenting with concurrent PHP-Ia and gonadotropin-independent sexual precocity (testotoxicosis). Mutational screening by denaturing gradient gel electrophoresis and sequencing of PCR-amplified exons of the G alpha s gene revealed a point mutation which generates an alanine-to-serine substitution in codon 366 of one G alpha s allele (A366S), an alanine present at the homologous position in all G-proteins. We have previously shown in transfected testis cells that the A366S mutation activates G alpha s by decreasing affinity for GDP, thereby increasing the rate of nucleotide exchange in a receptor-independent fashion. In contrast to differential stability of the activated mutant G alpha s protein in Leydig cells, with stability at 32 degrees C but not at 37 degrees C, skin fibroblasts with the mutation had the same reduced G alpha s levels at both temperatures. Our findings explain the limitation of clinical manifestations of G alpha s overactivity to testis, without involvement of other body appendages which are generally at lower than core body temperature. This unique mutation at a critically conserved residue of G alpha s is the first mutant G-protein which affects guanine nucleotide affinity and is associated with human disease, producing widely divergent and tissue-specific effects.


Assuntos
Proteínas de Ligação ao GTP/genética , Pseudo-Hipoparatireoidismo/genética , Puberdade Precoce/genética , Northern Blotting , Western Blotting , Códon , Eletroforese em Gel de Poliacrilamida , Éxons , Humanos , Lactente , Masculino , Linhagem , Reação em Cadeia da Polimerase , Mapeamento por Restrição
6.
Prenat Diagn ; 15(4): 363-7, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7617578

RESUMO

Mitochondrial acetoacetyl-coenzyme A (CoA) thiolase deficiency is an organic aciduria which affects isoleucine and ketone body catabolism. GK16 (the index patient) was affected with this disorder and previous studies had revealed that GK16 was a compound heterozygote with IVS8(+1) gt to tt and A301P mutations. In a subsequent pregnancy, prenatal diagnosis was performed and the fetus's amniocytes were analysed by the polymerase chain reaction (PCR) followed by the heteroduplex detection method on a Mutation Detection Enhancement gel. The fetus was identified as a carrier of the IVS8(+1) mutation. We confirmed the diagnosis by immunoblot analysis of extracted amniocytes and gene analysis with blood filter paper after delivery. This is the first report of prenatal diagnosis of this disorder at the gene level.


Assuntos
Acetil-CoA C-Acetiltransferase/deficiência , Mitocôndrias/enzimologia , Ácidos Nucleicos Heteroduplexes/análise , Reação em Cadeia da Polimerase/métodos , Diagnóstico Pré-Natal , Acetil-CoA C-Acetiltransferase/genética , Impressões Digitais de DNA , Análise Mutacional de DNA , Éxons , Feminino , Humanos , Mutação , Polimorfismo de Fragmento de Restrição , Gravidez
7.
Int J Pept Protein Res ; 42(6): 497-503, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8307680

RESUMO

The objective of this study was to determine whether the rates of deamidation of Asn8 in selected growth hormone releasing factor (GRF) analogs were related to the peptide's secondary structures in solution. Bovine or human [Leu27]GRF(1-32)NH2 (both having Gly at position 15), [Ala15Leu27]bGRF(1-32)NH2 and [Pro15Leu27]bGRF(1-32)NH2 were used as model peptides. The peptide helical content (assessed by CD) increased with the increasing methanol concentration and was as follows: 7, 12 and 18% in 0% MeOH; 24, 48 and 52% in 40% MeOH; and 41, 77 and 81% in 80% MeOH for Pro15Leu27 bGRF(1-32)NH2, [Leu27]hGRF(1-32)NH2 and Ala15Leu27 bGRF(1-32)NH2, respectively. 2D NMR studies done in the presence of 40% CD3OH indicated more helical structure for the Ala15 analog as compared to [Leu27]hGRF(1-32)NH2. In both these peptides Asn8 was included in the helical region. In contrast, the lack of conformational information for the Pro15 analog indicated little helical structure around Asn8. The peptides' deamidation rates decreased and their half-lives increased with increasing MeOH concentrations. At 40% MeOH, the least helical Pro15 bGRF analog (t1/2 = 10.78 h) deamidated 1.5 and 2 times faster than its Gly15 (t1/2 = 15.74 h) and Ala15 (t1/2 = 21.53 h) counterparts, respectively. This study indicates that helical environment around Asn8 in GRF makes this residue less prone to deamidation.


Assuntos
Asparagina/metabolismo , Hormônio Liberador de Hormônio do Crescimento/análogos & derivados , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Estrutura Secundária de Proteína , Sequência de Aminoácidos , Animais , Bioensaio , Bovinos , Dicroísmo Circular , Hormônio Liberador de Hormônio do Crescimento/química , Hormônio Liberador de Hormônio do Crescimento/farmacologia , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Hipófise/citologia , Hipófise/efeitos dos fármacos
8.
Int J Pept Protein Res ; 42(1): 24-32, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8370640

RESUMO

The solution structure and helical content of a human growth hormone releasing factor analog, Leu27 hGRF(1-32)NH2 (hGRF), and its deamidation products Asp8 Leu27 hGRF(1-32)NH2 and isoAsp8 Leu27 hGRF(1-32)NH2, were determined by CD and 2D NMR. Chemical-shift assignments of 1H NMR resonances were made from DQFCOSY, HOHAHA and NOESY spectra, and qualitative secondary structure was determined from NOESY spectra. 2D NMR studies in aqueous MeOH showed the Asn8, Asp8 and isoAsp8 hGRF analogs to have significant alpha-helical character. However, the beta-linked isoAsp8 analog did not retain helical structure in the N-terminal region, most likely because of disruption of the hydrogen bonding pattern upon substitution of the extra methylene into the peptide backbone. The helical content, as determined by CD, was approximately 12% in 0% MeOH for all three peptides, and 77, 72 and 69% in 80% MeOH for the Asn8, Asp8 and isoAsp8 hGRF analogs, respectively. However, 2D NMR solution structure data indicated a decrease in helicity in the N-terminal region for the isoAsp8 analog when compared with the other two analogs. In the Asn8 and Asp8 hGRF analogs, the helix began at Asp3 or Ala4, while the isoAsp8 analog helix was disrupted until Arg11. The higher helicity value for the Asn8 peptide over the isoAsp8 analog may be associated with reported biological activity, where the in vitro activity decreased from 100 to 4 and < 1% for Asn8, Asp8 and isoAsp8 hGRF, respectively.


Assuntos
Hormônio Liberador de Hormônio do Crescimento/análogos & derivados , Sequência de Aminoácidos , Animais , Bovinos , Dicroísmo Circular , Hormônio Liberador de Hormônio do Crescimento/química , Hormônio Liberador de Hormônio do Crescimento/farmacologia , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Adeno-Hipófise/efeitos dos fármacos , Conformação Proteica , Estrutura Secundária de Proteína , Soluções , Relação Estrutura-Atividade
9.
Biophys J ; 63(5): 1185-209, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1477272

RESUMO

Looking at proteins is an active process of interpretation and selection, emphasizing some features and deleting others. Multiple representations are needed, for such purposes as showing motions or conveying both the chain connectivity and the three-dimensional shape simultaneously. In studying and comparing protein structures, ideas are suggested about the determinants of tertiary structure and of folding (e.g., that Greek key beta barrels may fold up two strands at a time). The design and synthesis of new proteins "from scratch" provides a route toward the experimental testing of such ideas. It has also been a fruitful new perspective from which to look at structures, requiring such things as statistics on very narrowly defined structural categories and explicit attention to "negative design" criteria that actively block unwanted alternatives (e.g., reverse topology of a helix bundle, or edge-to-edge aggregation of beta sheets). Recently, the field of protein design has produced a rather unexpected general result: apparently we do indeed know enough to successfully design proteins that fold into approximately correct structures, but not enough to design unique, native-like structures. The degree of order varies considerably, but even the best designed material shows multiple conformations by NMR, more similar to a "molten globule" folding intermediate than to a well ordered native tertiary structure. In response to this conclusion, we are now working on systems that test useful questions with approximate structures (such as determining which factors most influence the choice of helix-bundle topology) and also analyzing how natural proteins achieve unique core conformations (e.g., for side chains on the interior side of a beta sheet, illustrated in the kinemages).


Assuntos
Proteínas/química , Sequência de Aminoácidos , Fenômenos Biofísicos , Biofísica , Desenho de Fármacos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Molecular , Conformação Proteica , Proteínas/ultraestrutura
10.
J Biomol NMR ; 2(5): 407-20, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1422154

RESUMO

The solution conformation of human big endothelin-1, a 38-residue peptide which serves as the putative precursor to the potent vasoconstrictor endothelin-1 has been examined by 1H NMR. NOEs were utilized as distance restraints in the distance geometry program DSPACE to generate initial structures. Further refinement of these structures was accomplished through molecular mechanics/molecular dynamics in an iterative process involving the incorporation of stereospecific assignments of prochiral centers and the use of back-calculation of NOESY spectra. A family of structures consisting of a type II beta-turn for residues 5-8 and an alpha-helix extending from residues 9-16 constitute a well-defined region, as reflected by the atomic root-mean-square (RMS) difference of 1.56 A about the mean coordinate positions of the backbone atoms (N, C, C alpha and O). This core region (residues 1-15) is very similar to the core residues of endothelin-1 (Donlan, M. et al. (1991) J. Cell. Biochemistry, S15G, 85). While the evidence from NOESY and coupling constant data suggests that the C-terminal region, residues 17-34, is not a mixture of randomly distributed chain conformations, it is also not consistent with a single chain conformation. Under the conditions studied, residues 17-38 in human big endothelin-1 in water at pH 3.0 between 20-30 degrees C appear to be represented by a series of conformers in dynamic equilibrium.


Assuntos
Endotelinas/química , Conformação Proteica , Precursores de Proteínas/química , Sequência de Aminoácidos , Endotelina-1 , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Soluções/química
11.
Nucleic Acids Res ; 20(3): 525-32, 1992 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-1311077

RESUMO

A dynamic heterogeneity which correlates with the function of the operator DNA in the lactose operon of E. coli. was previously observed (1) as a local minimum in the thymine imino proton T1 centered at a GTG/C-CAC sequence. Since this triplet occurs frequently in DNA regulatory regions, it was proposed that these sequences may be part of a structural element for specific protein interaction. We examine here three additional biologically significant 17 base pair duplexes containing GTG/CAC triplets: (1) a sequence from the mouse heavy chain immunoglobulin enhancer, (2) a sequence from the critical core of the Simian Virus 40 (SV40) enhancer, and (3) a sequence from pBR322 plasmid used as control for experiments with the SV40 DNA sequences. The 1H NMR resonance assignment for nearly all the nonexchangeable protons for both eukaryotic enhancer duplexes with the exception of the H5'/H5" protons was accomplished to use for structural analysis of these duplexes. The data presented show several NOE's associated with the GTG/CAC triplets which suggest structural variation from uniform B-DNA. In addition, anomalous broad crosspeaks for the fixed thymine methyl to its own H6 proton in combination with the imino proton kinetics associated with these triplets reinforces the original observation of a sequence dependent dynamic variation.


Assuntos
Elementos Facilitadores Genéticos/genética , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Transcrição Gênica/genética , Animais , Sequência de Bases , Cadeias Pesadas de Imunoglobulinas/genética , Espectroscopia de Ressonância Magnética , Camundongos , Dados de Sequência Molecular , Plasmídeos/genética , Vírus 40 dos Símios/genética , Temperatura
13.
J Pediatr ; 116(4): 581-6, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2319405

RESUMO

Thirteen patients with hypopigmentation of the skin characteristic of hypomelanosis of Ito, and with developmental disabilities or structural malformations, or both, were examined at our center. Eight were found to have abnormal karyotypes in lymphocytes, fibroblasts, or both. No single clinical feature was predictive of chromosome imbalance in this group of patients. Cytogenetic findings included a balanced de novo X-autosome translocation; ring 10; 45,X/46,X,+ring; mosaic del 13q11 (fibroblasts); mosaic triploidy (fibroblasts); mosaic tetrasomy 12p (fibroblasts); mosaic apparently balanced 15;22 translocation (peripheral blood); and mosaic trisomy 18 (peripheral blood). Hypomelanosis of Ito is characterized by swirly hypopigmentation or depigmentation of the skin with or without other malformations. Autosomal dominant, autosomal recessive, and X-linked dominant inheritance have been suggested but not confirmed. Chromosomal aneuploidy has also been reported. We believe that hypomelanosis of Ito is an etiologically heterogeneous physical finding, and recommend karyotyping of multiple tissues of all patients with abnormal cutaneous pigmentation associated with developmental delay or structural malformations.


Assuntos
Aberrações Cromossômicas/genética , Mosaicismo/genética , Transtornos da Pigmentação/genética , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Cariotipagem , Masculino , Transtornos da Pigmentação/patologia , Síndrome , Translocação Genética , Cromossomo X
15.
Am J Med Genet ; 27(1): 189-94, 1987 May.
Artigo em Inglês | MEDLINE | ID: mdl-3605195

RESUMO

We report on a male with trisomy Xq resulting from an isochromosome Xq which is preferentially inactivated: 47,XY,+i(Xq). Six previous cases have been reported. These patients are similar to patients with classical Klinefelter syndrome (47,XXY) in that they have infertility, decreased masculinization, gynecomastia, and elevated luteinizing hormone (LH) and follide stimulating hormone (FSH) levels. They may differ in having average intelligence and normal to short stature. These findings indicate that extra copies of the long arm of X have phenotypic expression, even though activated only in early development.


Assuntos
Síndrome de Klinefelter/genética , Cromossomo X , Adolescente , Estatura , Mecanismo Genético de Compensação de Dose , Humanos , Inteligência , Síndrome de Klinefelter/patologia , Síndrome de Klinefelter/psicologia , Masculino , Fenótipo
17.
Am J Med Genet ; 24(1): 171-4, 1986 May.
Artigo em Inglês | MEDLINE | ID: mdl-3706404

RESUMO

Inheritance of ring chromosomes is reported infrequently. We report on a mother and her son both with a ring 18 chromosome, and describe the associated manifestations. The son had microcephaly, ptosis, short stature, and mental retardation; the mother was mentally retarded and had a similar facial appearance.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos 16-18 , Cromossomos em Anel , Adolescente , Adulto , Feminino , Transtornos do Crescimento/genética , Humanos , Deficiência Intelectual/genética , Masculino , Microcefalia/genética
18.
Biophys J ; 49(1): 26-9, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19431632
20.
Adv Biophys ; 20: 153-75, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-2422883

RESUMO

Variation in the observed spin lattice relaxation rate (Robs) interpreted as proton exchange dominated in sequences corresponding to part of promoters where RNA polymerase initiates mRNA synthesis has been observed by both Patel et al. and Reid and co-workers. A higher Robs was also seen in the TA pair of the GTG/CAC in the sequence corresponding to the lambda phage cro repressor binding site by Kyogoku et al. As we pointed out in the introduction, the one case where a three-dimensional structure for a turn of a helix is known shows clear structural heterogeneity which has led to detailed consideration of geometry of regulatory regions. Nussinov and collaborators have generalized the details of the Dickerson dodecomer to note potential similarities in operators including the lac system and the enhancer sequences described above. Like the steric considerations of Calladine and Dickerson and nearest neighbor structure analysis of Bubienko et al., the focus is on the geometry of a sequence leading to base tilt angles and potential overlap since they are measurable parameters. With the observation that the DNA molecule is both structurally and dynamically flexible, there will no doubt be many new variables that can be made as a function of DNA sequence. Biophysical chemists in some ways are like the intoxicated person searching for a lost key at a site different from where it was lost because that is where the light is best. Thus, each physical method has its most convenient observable. It is hoped that the above discussion illustrates that a very large and diverse set of biochemical results are awaiting detailed explanation in molecular terms using the illumination of high resolution physical techniques.


Assuntos
DNA/metabolismo , Proteínas/metabolismo , Anticorpos , Sequência de Bases , Sítios de Ligação , DNA/imunologia , Elementos Facilitadores Genéticos , Epitopos , Óperon Lac , Espectroscopia de Ressonância Magnética , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos , Prótons
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