RESUMO
Clinical exome sequencing (CES) is increasingly being used as an effective diagnostic tool in the field of pediatric genetics. We sought to evaluate the parental experience, understanding and psychological impact of CES by conducting a survey study of English-speaking parents of children who had diagnostic CES. Parents of 192 unique patients participated. The parent's interpretation of the child's result agreed with the clinician's interpretation in 79% of cases, with more frequent discordance when the clinician's interpretation was uncertain. The majority (79%) reported no regret with the decision to have CES. Most (65%) reported complete satisfaction with the genetic counseling experience, and satisfaction was positively associated with years of genetic counselor (GC) experience. The psychological impact of CES was greatest for parents of children with positive results and for parents with anxiety or depression. The results of this study are important for helping clinicians to prepare families for the possible results and variable psychological impact of CES. The frequency of parental misinterpretation of test results indicates the need for additional clarity in the communication of results. Finally, while the majority of patients were satisfied with their genetic counseling, satisfaction was lower for new GCs, suggesting a need for targeted GC training for genomic testing.
Assuntos
Deficiências do Desenvolvimento/genética , Sequenciamento do Exoma/métodos , Exoma/genética , Aconselhamento Genético , Adulto , Criança , Deficiências do Desenvolvimento/fisiopatologia , Revelação , Feminino , Testes Genéticos , Humanos , Masculino , Pais , Inquéritos e QuestionáriosRESUMO
AIMS: Occupational therapists (OTs) often face barriers when trying to collaborate with teachers in school-based settings. Partnering for change (P4C), a collaborative practice model designed to support children with developmental coordination disorder, could potentially support all students with special needs. Therefore, the aim of this study was to explore how teachers experience OT services delivered using the P4C model to support children with a variety of special needs. METHODS: P4C was implemented at one elementary school in Courtenay, British Columbia. Eleven teachers participated in two focus groups and a one-on-one interview to gather descriptive, qualitative data. Grounded theory techniques were used for data analysis. RESULTS: Four themes (collaborating in the thick of it all, learning and taking risks, managing limited time and resources, and appreciating responsive OT support) represented teachers' experiences of P4C. CONCLUSIONS: Teachers strongly preferred collaborative OT services based on the P4C model. Students with a variety of special needs were supported within their classrooms as teachers learned new strategies from the OT and found ways to embed these strategies into their daily routines.
Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Transtornos das Habilidades Motoras/reabilitação , Terapia Ocupacional/métodos , Professores Escolares/estatística & dados numéricos , Criança , Comportamento Cooperativo , Crianças com Deficiência/reabilitação , Grupos Focais , Humanos , Pesquisa Qualitativa , Serviços de Saúde EscolarRESUMO
Identification of rare genetic variants in patients with intellectual disability (ID) has been greatly accelerated by advances in next generation sequencing technologies. However, due to small numbers of patients, the complete phenotypic spectrum associated with pathogenic variants in single genes is still emerging. Among these genes is ZBTB18 (ZNF238), which is deleted in patients with 1q43q44 microdeletions who typically present with ID, microcephaly, corpus callosum (CC) abnormalities, and seizures. Here we provide additional evidence for haploinsufficiency or dysfunction of the ZBTB18 gene as the cause of ID in five unrelated patients with variable syndromic features who underwent whole exome sequencing revealing separate de novo pathogenic or likely pathogenic variants in ZBTB18 (two missense alterations and three truncating alterations). The neuroimaging findings in our cohort (CC hypoplasia seen in 4/4 of our patients who underwent MRI) lend further support for ZBTB18 as a critical gene for CC abnormalities. A similar phenotype of microcephaly, CC agenesis, and cerebellar vermis hypoplasia has been reported in mice with central nervous system-specific knockout of Zbtb18. Our five patients, in addition to the previously described cases of de novo ZBTB18 variants, add to knowledge about the phenotypic spectrum associated with ZBTB18 haploinsufficiency/dysfunction.
Assuntos
Deficiência Intelectual/genética , Mutação , Proteínas Repressoras/genética , Anormalidades Múltiplas/genética , Adulto , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 1/genética , Exoma , Feminino , Haploinsuficiência , Humanos , Imageamento por Ressonância Magnética , Masculino , Microcefalia/genética , Mutação de Sentido Incorreto , GravidezRESUMO
UNLABELLED: Urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. The susceptibility of this enzyme to chemical inhibition was determined using soluble extracts of Staph. saprophyticus strain ATCC 15305. Acetohydroxamic acid (Ki = 8.2 µg ml(-1) = 0.106 mmol l(-1) ) and DL-phenylalanine hydroxamic acid (Ki = 21 µg ml(-1) = 0.116 mmol l(-1) ) inhibited urease activity competitively. The phosphorodiamidate fluorofamide also caused competitive inhibition (Ki = 0.12 µg ml(-1) = 0.553 µmol l(-1) = 0.000553 mmol l(-1) ), but the imidazole omeprazole had no effect. Two flavonoids found in green tea extract [(+)-catechin hydrate (Ki = 357 µg ml(-1) = 1.23 mmol l(-1) ) and (-)-epigallocatechin gallate (Ki = 210 µg ml(-1) = 0.460 mmol l(-1) )] gave mixed inhibition. Acetohydroxamic acid, DL-phenylalanine hydroxamic acid, fluorofamide, (+)-catechin hydrate and (-)-epigallocatechin gallate also inhibited urease activity in whole cells of strains ATCC 15305, ATCC 35552 and ATCC 49907 grown in a rich medium or an artificial urine medium. Addition of acetohydroxamic acid or fluorofamide to cultures of Staph. saprophyticus in an artificial urine medium delayed the increase in pH that normally occurs during growth. These results suggest that urease inhibitors may be useful for treating urinary tract infections caused by Staph. saprophyticus. SIGNIFICANCE AND IMPACT OF THE STUDY: The enzyme urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. We have shown that urease activity in cell-free extracts and whole bacterial cells is susceptible to inhibition by hydroxamates, phosphorodiamidates and flavonoids, but not by imidazoles. Acetohydroxamic acid and fluorofamide in particular can temporarily delay the increase in pH that occurs when Staph. saprophyticus is grown in an artificial urine medium. These results suggest that urease inhibitors may be useful as chemotherapeutic agents for the treatment of urinary tract infections caused by this micro-organism.
Assuntos
Inibidores Enzimáticos/farmacologia , Staphylococcus saprophyticus/enzimologia , Urease/antagonistas & inibidores , Amidas/farmacologia , Catequina/análogos & derivados , Catequina/farmacologia , Meios de Cultura , Flavonoides/farmacologia , Concentração de Íons de Hidrogênio , Ácidos Hidroxâmicos/farmacologia , Imidazóis/farmacologia , Cinética , Staphylococcus saprophyticus/efeitos dos fármacos , Staphylococcus saprophyticus/patogenicidade , Urease/metabolismo , Sistema Urinário/efeitos dos fármacos , Urina/microbiologia , Fatores de Virulência/antagonistas & inibidoresRESUMO
Systemic lupus erythematosus (SLE) is an autoimmune disease that can significantly impact both physiological and psychological functioning. In order to examine the relationship between psychological functioning and disease activity in SLE, we administered instruments that collected sociodemographic information and measured indices of disease activity and psychosocial functioning from 125 adult Hispanic and White patients with SLE. Patients were recruited from four healthcare settings in the greater Southern California area. Both cross-sectional and longitudinal relationships between depression and disease activity were evaluated. Cross-sectional findings revealed that depression and ethnicity were independently correlated with self-reported disease activity. Longitudinally, depression alone predicted self-reported disease activity. These data suggest that depression may play a significant role in the health status of SLE patients and serve as an important target for clinical intervention.
Assuntos
Transtorno Depressivo/psicologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Lúpus Eritematoso Sistêmico/psicologia , Índice de Gravidade de Doença , Adulto , California , Estudos Transversais , Etnicidade/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , AutoimagemRESUMO
Posttranslational modification of Rab proteins by geranylgeranyltransferase type II requires that they first bind to Rab escort protein (REP). Following prenylation, REP is postulated to accompany the modified GTPase to its specific target membrane. REP binds preferentially to Rab proteins that are in the GDP state, but the specific structural domains involved in this interaction have not been defined. In p21 Ras, the alpha2 helix of the Switch 2 domain undergoes a major conformational change upon GTP hydrolysis. Therefore, we hypothesized that the corresponding region in Rab1B might play a key role in the interaction with REP. Introduction of amino acid substitutions (I73N, Y78D, and A81D) into the putative alpha2 helix of Myc-tagged Rab1B prevented prenylation of the recombinant protein in cell-free assays, whereas mutations in the alpha3 and alpha4 helices did not. Additionally, upon transient expression in transfected HEK-293 cells, the Myc-Rab1B alpha2 helix mutants were not efficiently prenylated as determined by incorporation of [3H]mevalonate. Metabolic labeling studies using [32P]orthophosphate indicated that the poor prenylation of the Rab1B alpha2 helix mutants was not directly correlated with major disruptions in guanine nucleotide binding or intrinsic GTPase activity. Finally, gel filtration analysis of cytosolic fractions from 293 cells that were coexpressing T7 epitope-tagged REP with various Myc-Rab1B constructs revealed that mutations in the alpha2 helix of Rab1B prevented the association of nascent (i.e., nonprenylated) Rab1B with REP. These data indicate that the Switch 2 domain of Rab1B is a key structural determinant for REP interaction and that nucleotide-dependent conformational changes in this region are largely responsible for the selective interaction of REP with the GDP-bound form of the Rab substrate.
Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Ligação ao GTP/fisiologia , Proteínas rab de Ligação ao GTP , Proteínas rab1 de Ligação ao GTP , Proteínas Adaptadoras de Transdução de Sinal , Alquil e Aril Transferases/metabolismo , Substituição de Aminoácidos/genética , Sítios de Ligação/genética , Linhagem Celular , Proteínas de Ligação ao GTP/biossíntese , Proteínas de Ligação ao GTP/genética , Genes myc , Guanosina Trifosfato/metabolismo , Humanos , Rim/citologia , Mutagênese Sítio-Dirigida , Ligação Proteica/genética , Prenilação de Proteína/genética , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismoRESUMO
BACKGROUND: Research conducted by Ward, Muller, Tsourtos, et al. (Soc Sci Med 72(7):1140-1148, 2011) has led to the development of the psycho-social interactive model of resilience, which reveals the interaction between individual resilience factors (i.e. coping, confidence and self esteem) and external resilience environments (i.e. employment, supportive family environments and health promoting policies) in facilitating the development of resilience. This present study explored the utility of this model of resilience for understanding how people self-manage type-2 diabetes. METHODS: Data were collected via 14 semi-structured life-history interviews with women and men living with type-2 diabetes mellitus (T2DM). Participants varied according to socio-demographics (gender, age, education level, income) and were recruited based on their self-reported management (or lack thereof) of T2DM. RESULTS: The inter-play of internal traits and external resources with additive and subtractive resilience strategies were consistent with the psycho-social interactive model of resilience. Self-management was influenced by life history. Differences in self-management and material disadvantage were also identified. Alongside increased disadvantage are higher levels of external barriers to self-management practices. CONCLUSIONS: This paper supports the concepts of additive and subtractive resilience strategies for use with diabetes populations; providing health professionals and policy makers with an increased understanding of how to recognize and foster patient resilience for the improvement of self-care, disease management and ultimately health outcomes.
RESUMO
Adhesion turnover is critical for cell motility and invasion. We previously demonstrated that the adaptor molecule breast cancer antiestrogen resistance 3 (BCAR3) promotes adhesion disassembly and breast tumor cell invasion. One of two established binding partners of BCAR3 is the adaptor molecule, p130Cas. In this study, we sought to determine whether signaling through the BCAR3-Cas complex was responsible for the cellular functions of BCAR3. We show that the entire pool of BCAR3 is in complex with Cas in invasive breast tumor cells and that these proteins colocalize in dynamic cellular adhesions. Although accumulation of BCAR3 in adhesions did not require Cas binding, a direct interaction between BCAR3 and Cas was necessary for efficient dissociation of BCAR3 from adhesions. The dissociation rates of Cas and two other adhesion molecules, α-actinin and talin, were also significantly slower in the presence of a Cas-binding mutant of BCAR3, suggesting that turnover of the entire adhesion complex was delayed under these conditions. As was the case for adhesion turnover, BCAR3-Cas interactions were found to be important for BCAR3-mediated breast tumor cell chemotaxis toward serum and invasion in Matrigel. Previous work demonstrated that BCAR3 is a potent activator of Rac1, which in turn is an important regulator of adhesion dynamics and invasion. However, in contrast to wild-type BCAR3, ectopic expression of the Cas-binding mutant of BCAR3 failed to induce Rac1 activity in breast cancer cells. Together, these data show that the ability of BCAR3 to promote adhesion disassembly, tumor cell migration and invasion, and Rac1 activity is dependent on its ability to bind to Cas. The activity of BCAR3-Cas complexes as a functional unit in breast cancer is further supported by the co-expression of these molecules in multiple subtypes of human breast tumors.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteína Substrato Associada a Crk/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Neoplasias da Mama/genética , Proteínas de Transporte/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proteína Substrato Associada a Crk/genética , Feminino , Fibroblastos , Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina , Humanos , Camundongos , Modelos Biológicos , Complexos Multiproteicos/metabolismo , Ligação ProteicaRESUMO
The reactive sulfhydryls of human adult and fetal hemoglobin and the single sulfhydryl of isolated gamma chains have been spin labeled with N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolidinyl) iodoacetamide. Similar electron paramagnetic spectral differences between oxy- and deoxy-modified hemoglobins were observed for both these hemoglobins and for the isolated chains, indicating that ligand-induced conformational changes occur in isolated hemoglobin subunits as well as intact hemoglobin tetramers. Ligand induced changes in the reactivity of p-hydroxymercuribenzoate with the sulfhydryl groups of both intact hemoglobins and isolated subunits, observed by McDonald and Noble (1974) J. Biol. Chem. 249, 3161-3165), led them to draw a similar conclusion. Following carboxypeptidase A digestion of these modified hemoglobins and gamma chains, a procedure which specifically removes the two C-terminal residues of the beta or gamma chains, spectral differences between the liganded and unliganded spin-labeled derivatives still persisted. However, the magnitude of this difference was not only more reduced in the case of the hemoglobins than in that of the subunits but the spectra of both the oxy and deoxy derivatives of the hemoglobins were characteristic of the oxy derivative of a cooperative tetrameric hemoglobin. These findings support the premise that the COOH-terminal end of the beta or gamma chain contributes, although possibly to different extents, to the spectral differences exhibited by both the spin-labeled hemoglobins and chains.
Assuntos
Hemoglobina Fetal , Hemoglobina A , Hemoglobinas , Carboxipeptidases/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Cinética , Ligantes , Peptídeos , Conformação Proteica/efeitos dos fármacos , Marcadores de Spin , Relação Estrutura-AtividadeRESUMO
Radial immunodiffusion can be used to determine relative antigen-antibody avidities in exactly the same way as demonstrated previously for quantitative immunoelectrophoresis (Birkmeyer et al., 1981). Antigen-antibody interactions of greater avidity result in a greater value of (delta Area/delta [Antigen]) in plots of immunoprecipitin circle area versus antigen concentration while interactions of equal avidity will yield equal values of (delta Area/delta [Antigen]). This was demonstrated using antigens of different weight ranging from 8000 to 66,000.
Assuntos
Complexo Antígeno-Anticorpo/análise , Hemoglobina A/imunologia , Inibidores da Tripsina/imunologia , Hemoglobina A/análise , Soros Imunes , Imunodifusão/métodos , Imunoeletroforese/métodos , Plantas , Inibidores da Tripsina/análiseRESUMO
The relative affinities of an antibody population of different antigens or of different antibody populations for one antigen can be determined by quantitative immunoelectrophoresis. Antigen-antibody interactions of greater average affinity result in a greater increase in rocket area as a function of the amount of antigen applied to the wells. This is measured as the slope of the line in plots of rocket area versus antigen amount. Quantitative immunoelectrophoresis of different antigens, which nevertheless have the same affinity for antibody, produces plots with the same slopes. The relative magnitudes of the slopes of these lines reflect the relative average affinities of different antibody populations for an antigen.
Assuntos
Afinidade de Anticorpos , Antígenos/imunologia , Animais , Especificidade de Anticorpos , Reações Cruzadas , Cabras , Hemoglobina A , Hemoglobina A2 , Humanos , Imunoeletroforese , CoelhosRESUMO
We have provided a detailed protocol for the synthesis of a yohimbine-agarose matrix that has been shown to be effective for isolation of the alpha 2A-adrenergic receptor from human platelet and purification of the alpha 2A-adrenergic receptor to apparent homogeneity from porcine brain cortex using chromatography on only two sequential yohimbine-agarose columns. In addition, this affinity matrix also interacts with alpha 2 receptors of the alpha 2B subtype extracted from cultured NG108-15 cells. Finally, this affinity matrix has proven useful for monitoring posttranslational modifications of the receptor in digitonin extracts of metabolically labeled cells. Thus, this affinity matrix can be exploited for the purification of multiple alpha 2-adrenergic receptor subtypes on both a macro- and microscale and should be of value to any laboratory exploring the molecular basis for alpha 2-adrenergic functions.
Assuntos
Plaquetas/metabolismo , Receptores Adrenérgicos alfa/isolamento & purificação , Sefarose/análogos & derivados , Ioimbina/análogos & derivados , Agonistas alfa-Adrenérgicos/metabolismo , Fracionamento Celular/métodos , Cromatografia de Afinidade/métodos , Digitonina , Humanos , Indicadores e Reagentes , Ensaio Radioligante/métodos , Receptores Adrenérgicos alfa/análise , Receptores Adrenérgicos alfa/metabolismo , Sefarose/síntese química , Trítio , Ioimbina/sangue , Ioimbina/síntese químicaRESUMO
The National Center for Health Statistics reports that in 1983 65% of all infant deaths in the United States occurred in the neonatal period. Of these reported neonatal deaths, 17% were of infants weighing less than 500 g at birth. There was, however, variation in state-reported incidence of live births of newborns in this weight cohort (0.2 to 2.2 per 1,000 live births). The states with the lowest neonatal mortality rate have the lowest incidence of birth weights less than 500 g (rho = .77). If it is assumed that mortality for this weight category is nearly 100%, there is marked variation (5% to 32%) in the contribution of this weight cohort to a state's total neonatal mortality rate. Contributing to this variation may be definitions of live birth used by states. The World Health Organization defines a live birth as the product of conception showing signs of life "irrespective of the duration of pregnancy" and this definition is used by 33 states. Only one state (Ohio) includes the gestational criteria of "at least 20 weeks" in its definition of live birth. There is evidence to suggest that definitions are not uniformly used within individual states. For example, in 1983, 20 states did not report any live births with weights less than 500 g among their "other" populations of nonwhite, nonblack residents. Half of these states, however, use the World Health Organization definition of live birth. Despite the exclusionary wording in Ohio's definition of liver birth, 16% of newborns who died in that state had birth weights less than 500 g.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Mortalidade Infantil , Recém-Nascido de Baixo Peso , Estatística como Assunto , Feminino , Morte Fetal , Humanos , Recém-Nascido , Gravidez , Estados UnidosRESUMO
The emotional responses of eight families who lost a singleton newborn were compared with those of eight families who lost a twin. The mean gestational age of the babies in both groups was 31 weeks. At a mean time of 15 months following their loss, parents were sent a questionnaire which requested that they report their responses during the first six weeks following their baby's death and their present response to this experience. Embedded in the questionnaire was a 20-item depression symptom inventory. Analysis of variance indicated that although mothers experienced significantly more depressive symptoms than fathers (F = 59.48, P = .001) and that all symptoms had diminished greatly over time (F = 6.02, P = .032), there was no significant difference between the parents who had lost a twin and those who had lost a singleton. However, family, friends, and hospital staff frequently ignored or downplayed the death of the twin assuming that the grief of the parents would be minimal because of the surviving twin. Results of this study indicate that the presence of a living twin in no way lessens the grieving process and that a conscious effort needs to be made to allow parents to express openly their feelings of loss when a twin dies.
Assuntos
Atitude Frente a Morte , Pesar , Recém-Nascido , Pais/psicologia , Gêmeos , Adulto , Atitude do Pessoal de Saúde , Aconselhamento , Depressão , Feminino , Humanos , Masculino , GravidezRESUMO
Using the radioligand H1 antagonist [3H]pyrilamine, we have characterized the histamine type 1 receptor on cloned murine natural suppressor cells (NS). A single, specific binding site for [3H]pyrilamine exists on these cells. The binding was saturable and reversible by various specific H1 receptor antagonists. The rank order of potency for displacement of [3H]pyrilamine binding from the H1 receptor by H1 receptor antagonists was promethazine = pyrobutamine greater than pyrilamine greater than diphenhydramine greater than chlorpheniramine. The histamine type-2 agonists, impromidine and dimaprit, and antagonists, cimetidine and ranitidine, as well as selected non-histamine agonists, did not displace [3H]pyrilamine from its binding sites on the natural suppressor cells. The data indicate that the theoretical KD was 1.1 +/- 0.3 X 10(-7) M while the measured KD of binding for [3H]pyrilamine was 6.0 +/- 0.8 X 10(-8) M; the maximum binding was 4.13 nM and the number of binding sites/cell was 2.14 +/- 0.29 X 10(6) (N = 3).
Assuntos
Receptores Histamínicos H1/metabolismo , Receptores Histamínicos/metabolismo , Linfócitos T Reguladores/metabolismo , Animais , Sítios de Ligação , Ligação Competitiva , Células Cultivadas , Interpretação Estatística de Dados , Antagonistas dos Receptores Histamínicos H1/metabolismo , Cinética , Pirilamina/metabolismo , Ratos , BaçoRESUMO
Cadherins are cell adhesion molecules that regulate development of a variety of tissues and maintenance of adult structures. In this study, we examined expression of two zebrafish classical cadherins, cadherin-2 and cadherin-4, in the cerebellum of developing, normal adult, and regenerating adult zebrafish using in situ hybridization and immunohistochemical methods. Cadherin-2 was widely expressed by the cerebellum of embryonic (24-50-h post fertilization) and larval zebrafish (3-14 days). Cadherin-2 expression became much reduced in the adult cerebellum, but it was greatly up-regulated in the regenerating adult cerebellum. Cadherin-4 was not detected in the embryonic cerebellum, but it was expressed in the Purkinje cells of the larval and adult cerebellum. To gain insight into cadherin-2 role in the formation of the cerebellum, we analyzed embryos injected with a specific cadherin-2 antisense morpholino oligonucleotide (cdh2MO1), and found that the cerebellar development of the cdh2MO1-injected embryos was severely disrupted. This phenotype was confirmed by examining a cadherin-2 mutant, glass onion. Our results suggest that cadherins are crucial for the normal development of the zebrafish cerebellum, and they may also be involved in the regeneration of injured fish cerebellum.
Assuntos
Caderinas/metabolismo , Cerebelo/crescimento & desenvolvimento , Cerebelo/metabolismo , Larva/crescimento & desenvolvimento , Larva/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Animais , Caderinas/genética , Cerebelo/citologia , Regulação para Baixo/genética , Larva/citologia , Regeneração Nervosa/genética , Oligonucleotídeos Antissenso/farmacologia , Células de Purkinje/citologia , Células de Purkinje/metabolismo , RNA Mensageiro/metabolismo , Regulação para Cima/genética , Peixe-Zebra/anatomia & histologiaRESUMO
The mung bean (Vigna radiata (L.) Wilczek) trypsin inhibitor (MBTI) is rapidly modified by limited proteolysis during the early stages of seedling growth. Using an electrophoretic assay that separates the unmodified inhibitor (MBTI-F) and the first two modified species (MBTI-E and -C), a pH optimum of approximately 4 was found for the modification reaction. The inhibitor modifying activity is initially low in ungerminated seeds, with the reaction F leads to E being the primary reaction catalyzed. Activity catalyzing the production of MBTI-C appears on the first day of germination. This activity (F leads to E leads to C) increases up to 6 days after inhibition, at which time the cotyledons begin to abscise. The activity converting MBTI-F and -E to MBTI-C was strongly inhibited by phenylmethylsulfonyl fluoride (3.3 mM) but only weakly by iodoacetate (9 mM) and not at all by pepstatin A (9 microM), leupeptin (18 microM), or EDTA (5 mM). These results suggest the involvement of proteinases other than the major endopeptidase of the germinating seed, vicilin peptidohydrolase. This conclusion is further supported by gel filtration of the extracts of cotyledons on Sephacryl S-200. At least three proteinases are present in germinated cotyledons capable of modifying MBTI-F to MBTI-C and/or -E. All are distinguishable from vicilin peptidohydrolase on the basis of their molecular weight and inhibition by low molecular weight organic reagents.
Assuntos
Endopeptidases/metabolismo , Fabaceae/enzimologia , Plantas Medicinais , Inibidores da Tripsina/metabolismo , Cromatografia em Gel , Peso Molecular , Proteínas de Plantas/metabolismo , Sementes/enzimologiaRESUMO
The degradation of the beta-conglycinin protein reserves in soybean seeds during germination and early growth begins with the proteolysis of its alpha and alpha' subunits by an enzyme called Protease C1. In the pathway, a number of proteolytic intermediates are produced and subsequently degraded. Determination of the N-terminal sequences of these intermediates provides insight regarding the requirements of the cleavage sites. The N-terminal sequence of three such proteolytic intermediates has been determined. The sequence has been located in the published sequences of the beta-conglycinin subunits. Comparing these cleavage sites, plus those of two others previously delineated, shows that the P1' and P4' positions always bear either a Glu or an Asp residue while the P1 position always bears either a Glu or a Gln residue. In addition, other sites from P3 to P7' are also rich in either Glu or Asp, and the whole region is predicted to be in a alpha-helix. Consistent with the observation, synthetic poly-L-Glu inhibits the Protease C1-catalysed degradation of the alpha and alpha' subunits of beta-conglycinin. Poly-L-Glu (av. M(r) = 1000) at 12.5 mM was more effective at inhibiting the reaction than poly-L-Glu (av. M(r) = 600) or poly-L-Glu (av. M(r) = 14,300) at the same concentration. Comparing large synthetic polypeptides at 12.5mM, inhibition by poly-L-Asp (av. M(r) = 15,000) is as effective as poly-L-Glu (av. M(r) = 14,300), while poly-L-Ser (av. M(r) = 15,000) had no effect at all. Poly-D-Glu (av. M(r) = 15,000) is a better inhibitor than poly-L-Glu of the same size. A serine protease of similar molecular weight as Protease C1 and also capable of catalysing the proteolysis of the alpha and alpha' subunits of beta-conglycinin to generate proteolytic intermediates of the same size has been found in mung bean.
Assuntos
Endopeptidases/metabolismo , Globulinas/metabolismo , Glycine max/enzimologia , Proteínas de Soja , Sequência de Aminoácidos , Antígenos de Plantas , Eletroforese em Gel de Poliacrilamida , Germinação , Globulinas/química , Substâncias Macromoleculares , Dados de Sequência Molecular , Peso Molecular , Oligopeptídeos/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Estrutura Secundária de Proteína , Proteínas de Armazenamento de Sementes , Sementes , Especificidade por SubstratoRESUMO
In view of the cholinergic deficits present in patients with Alzheimer's disease (AD), a widely investigated treatment strategy for the cognitive deficits in AD is cholinergic stimulation. Although nicotinic cholinergic receptor binding has been demonstrated to be deficient in the AD brain, the predominant theoretical and therapeutic focus to date has been on muscarinic cholinergic receptors and systems. The purpose of the present study was to evaluate the effects of sustained nicotine administration on behavior, cognition, and physiology. A double-blind placebo-controlled trial was conducted in which six patients with probable AD were exposed to 7, 8, and 7 days of placebo, nicotine, and washout, respectively. Daily sessions evaluating learning, memory, and behavior were conducted. Global cognitive functioning, rest and activity levels, cardiac activity, and blood levels were also measured. Findings included improved learning during the nicotine condition, which persisted throughout washout. Memory, behavior, and global cognition were not significantly affected. Sustained administration of nicotine appeared to be safe, although sleep showed a significant decrease.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/psicologia , Aprendizagem/efeitos dos fármacos , Memória/efeitos dos fármacos , Nicotina/uso terapêutico , Administração Cutânea , Idoso , Idoso de 80 Anos ou mais , Cognição/efeitos dos fármacos , Método Duplo-Cego , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Nicotina/administração & dosagem , Nicotina/efeitos adversos , Projetos Piloto , Escalas de Graduação PsiquiátricaRESUMO
UNLABELLED: Air exchange rate data from two residential indoor air quality studies are presented. In the first investigation, over 500 residences in Southern California were sampled for three one-week periods from 1984 to 1985. Those data provided seasonal information for a broad range of residential characteristics in a large metropolitan area. In the second study, a probability sample of nearly 300 residences were sampled for a two-day period during the winter of 1991-1992 throughout the state of California. Air exchange rate is summarized by season, geographic area, and appliance type. Residence volumes are presented by cooking and heating appliance. The data approximately followed lognormal distributions. IMPLICATIONS: Indoor air quality and human exposure models often require estimates of air exchange rate and residence volumes. Application of those models to California residences can be improved by using the data distributions provided in this manuscript. Data distributions presented for heating and cooking appliances are useful for modeling the impact of indoor sources specific for those appliance types. Measured air exchange rate is also useful for modeling energy use for heating and cooling in residences.