RESUMO
This study aimed to assess the benefits and outcomes of squamous cell carcinoma (SCC) of the vulva managed in a cancer centre post-centralisation of cancer care in the UK. A retrospective study was performed to evaluate the demography and management outcomes of SCC of the vulva in a regional gynaecological cancer centre. The results were then compared with the Rhodes et al. (1998) population-based study. Over the years, disease demography remained largely unchanged. However, centralisation of cancer care has resulted in significant changes in the pattern of care. The number of cases managed has increased by 1.7 times and the permutation of surgeries have reduced from 15 to 4. There is also a significant increased in the number of lymphadenectomies performed (p = 0.003). These changes were accompanied by improvement in 5-year cause-specific survival (p = 0.055).
Assuntos
Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/terapia , Avaliação de Resultados em Cuidados de Saúde , Neoplasias Vulvares/mortalidade , Neoplasias Vulvares/terapia , Idoso , Carcinoma de Células Escamosas/patologia , Estudos de Coortes , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Gradação de Tumores , Estudos Retrospectivos , Análise de Sobrevida , Reino Unido/epidemiologia , Neoplasias Vulvares/patologiaRESUMO
FAH (fumarylacetoacetate hydrolase) catalyses the final step of tyrosine catabolism to produce fumarate and acetoacetate. HT1 (hereditary tyrosinaemia type 1) results from deficiency of this enzyme. Previously, we prepared a partial mimic of the putative tetrahedral intermediate in the reaction catalysed by FAH co-crystallized with the enzyme to reveal details of the mechanism [Bateman, Bhanumoorthy, Witte, McClard, Grompe and Timm (2001) J. Biol. Chem. 276, 15284-15291]. We have now successfully synthesized complete mimics CEHPOBA {4-[(2-carboxyethyl)-hydroxyphosphinyl]-3-oxobutyrate} and COPHPAA {3-[(3-carboxy-2-oxopropyl)hydroxyphosphinyl]acrylate}, which inhibit FAH in slow-onset tight-binding mode with K(i) values of 41 and 12 nM respectively. A high-resolution (1.35 A; 1 A=0.1 nm) crystal structure of the FAH.CEHPOBA complex was solved to reveal the affinity determinants for these compounds and to provide further insight into the mechanism of FAH catalysis. These compounds are active in vivo, and CEHPOBA demonstrated a notable dose-dependent increase in SA (succinylacetone; a metabolite seen in patients with HT1) in mouse serum after repeated injections, and, following a single injection (1 mumol/g; intraperitoneal), only a modest regain of FAH enzyme activity was detected in liver protein isolates after 24 h. These potent inhibitors provide a means to chemically phenocopy the metabolic defects of either HT1 or FAH knockout mice and promise future pharmacological utility for hepatocyte transplantation.
Assuntos
Materiais Biomiméticos/química , Materiais Biomiméticos/farmacocinética , Butiratos/química , Butiratos/farmacocinética , Hidrolases/antagonistas & inibidores , Compostos Organofosforados/química , Compostos Organofosforados/farmacocinética , Ácidos Fosfínicos/química , Ácidos Fosfínicos/farmacocinética , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , Animais , Sítios de Ligação , Materiais Biomiméticos/síntese química , Butiratos/sangue , Butiratos/síntese química , Cristalografia por Raios X , Humanos , Hidrolases/química , Hidrolases/metabolismo , Cinética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Estrutura Molecular , Compostos Organofosforados/sangue , Compostos Organofosforados/síntese química , Ácidos Fosfínicos/sangue , Ácidos Fosfínicos/síntese química , Inibidores de Proteases/sangue , Inibidores de Proteases/síntese química , Estrutura Terciária de Proteína , Fatores de TempoRESUMO
The DNA photosensitisers m-iodo Hoechst and m-iodo, p-methoxy Hoechst have been co-crystallised with the oligonucleotide d(CGCGAATTCGCG)(2)and their crystal structures determined. The crystals were then subjected to slow dehydration, which reduced their solvent contents from 40 (normal) to 30 (partially dehydrated) and then 20% (fully dehydrated) and caused a reduction in cell volume from 68,000 to 60,000 then 51,000 A(3). The dehydration resulted in a dramatic enhancement of diffraction resolution from approximately 2.6 to beyond 1.5 A. Crystal structures have also been determined for the partially and fully dehydrated states. The fully dehydrated crystals consist of an infinite polymeric network, in which neighbouring dodecamer duplexes are crosslinked through phosphate oxygens via direct bonding to bridging magnesium cations. This unique three-dimensional structure for DNA is described in detail in the following companion paper. The present paper details evidence from the sequence of crystal structures that the DNA is able to breathe locally, allowing the ligand to leave the minor groove, re-orient in the surrounding solvent medium and then re-enter the groove in a different orientation and location. The rearrangement of the minor groove binding ligands during the dehydration process mimics the binding behaviour of these ligands in solution and in vivo. We also present details of the DNA-ligand interactions that are consistent with a hydrogen atom ion mechanism for photocleavage of DNA.
Assuntos
DNA/química , Desenho de Fármacos , Corantes Fluorescentes/química , Animais , Humanos , Conformação de Ácido Nucleico , Radiossensibilizantes/químicaRESUMO
By controlled dehydration, the unit cells of dodecamer DNA-drug crystals have been shrunk from 68,000 (normal state) to 60,000 (partially dehydrated intermediate state) to 51,000 A(3) (fully dehydrated state), beyond which no further solvent loss occurs. The total solvent content in the normal crystals is approximately 40% by volume, reducing to approximately 20% in the fully dehydrated phase. The 25% reduction in cell volume induced a dramatic enhancement in the resolution of the X-ray diffraction data (from 2. 6 to beyond 1.5 A). We have determined the structures of the normal, partially dehydrated and fully dehydrated crystals. Details of the ligand binding have been presented in the preceding article. The present paper describes the unique features of the structure of the fully dehydrated phase. This structure was refined with 9,015 unique observed reflections to R = 14.9%, making it one of the most reliable models of B -form DNA available. The crystals exist as infinite polymeric networks, in which neighbouring dodecamer duplexes are crosslinked through phosphate oxygens via direct bonding to magnesium cations. The DNA is packed so tightly that there is essentially only a single layer of solvent between adjacent molecules. The details of the crystal packing, magnesium bridging, DNA hydration and DNA conformation are described and compared with other experimental evidence related to DNA condensation.
Assuntos
DNA/química , Conformação de Ácido Nucleico , Água , Animais , HumanosRESUMO
BACKGROUND: Thiamin pyrophosphokinase (TPK) catalyzes the transfer of a pyrophosphate group from ATP to vitamin B1 (thiamin) to form the coenzyme thiamin pyrophosphate (TPP). Thus, TPK is important for the formation of a coenzyme required for central metabolic functions. TPK has no sequence homologs in the PDB and functions by an unknown mechanism. The TPK structure has been determined as a significant step toward elucidating its catalytic action. RESULTS: The crystal structure of Saccharomyces cerevisiae TPK complexed with thiamin has been determined at 1.8 A resolution. TPK is a homodimer, and each subunit consists of two domains. One domain resembles a Rossman fold with four alpha helices on each side of a 6 strand parallel beta sheet. The other domain has one 4 strand and one 6 strand antiparallel beta sheet, which form a flattened sandwich structure containing a jelly-roll topology. The active site is located in a cleft at the dimer interface and is formed from residues from domains of both subunits. The TPK dimer contains two compound active sites at the subunit interface. CONCLUSIONS: The structure of TPK with one substrate bound identifies the location of the thiamin binding site and probable catalytic residues. The structure also suggests a likely binding site for ATP. These findings are further supported by TPK sequence homologies. Although possessing no significant sequence homology with other pyrophospokinases, thiamin pyrophosphokinase may operate by a mechanism of pyrophosphoryl transfer similar to those described for pyrophosphokinases functioning in nucleotide biosynthesis.
Assuntos
Saccharomyces cerevisiae/genética , Tiamina Pirofosfoquinase/química , Trifosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cristalografia por Raios X , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de Aminoácidos , Tiamina Pirofosfoquinase/metabolismo , Tiamina/metabolismoRESUMO
Thiamin pyrophosphate (TPP) is a coenzyme derived from vitamin B1 (thiamin). TPP synthesis in eukaryotes requires thiamin pyrophosphokinase (TPK), which catalyzes the transfer of a pyrophosphate group from ATP to thiamin. TPP is essential for central metabolic processes, including the formation of acetyl CoA from glucose and the Krebs cycle. Deficiencies in human thiamin metabolism result in beriberi and Wernicke encephalopathy. The crystal structure of mouse TPK was determined by multiwavelength anomalous diffraction at 2.4 A resolution, and the structure of TPK complexed with thiamin has been refined at 1.9 A resolution. The TPK polypeptide folds as an alpha/beta-domain and a beta-sandwich domain, which share a central ten-stranded mixed beta-sheet. TPK subunits associate as a dimer, and thiamin is bound in the dimer interface. Despite lacking apparent sequence homology with other proteins, the alpha/beta-domain resembles the Rossman fold and is similar to other kinase structures, including another pyrophosphokinase and a thiamin biosynthetic enzyme. Comparison of mouse and yeast TPK structures reveals differences that could be exploited in developing species-specific inhibitors of potential use as antimicrobial agents.
Assuntos
Tiamina Pirofosfoquinase/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Dimerização , Desenho de Fármacos , Camundongos , Modelos Moleculares , Conformação Proteica , Subunidades Proteicas , Saccharomyces cerevisiae/enzimologia , Especificidade da Espécie , Tiamina Pirofosfoquinase/metabolismo , Tiamina/metabolismoRESUMO
The mouse major urinary proteins are pheromone-binding proteins that function as carriers of volatile effectors of mouse physiology and behavior. Crystal structures of recombinant mouse major urinary protein-I (MUP-I) complexed with the synthetic pheromones, 2-sec-butyl-4,5-dihydrothiazole and 6-hydroxy-6-methyl-3-heptanone, have been determined at high resolution. The purification of MUP-I from mouse liver and a high-resolution structure of the natural isolate are also reported. These results show the binding of 6-hydroxy-6-methyl-3-heptanone to MUP-I, unambiguously define ligand orientations for two pheromones within the MUP-I binding site, and suggest how different chemical classes of pheromones can be accommodated within the MUP-I beta-barrel.
Assuntos
Feromônios/metabolismo , Proteínas/química , Proteínas/metabolismo , Animais , Sítios de Ligação , Cristalografia por Raios X , Ligação de Hidrogênio , Fígado/química , Camundongos , Modelos Moleculares , Feromônios/síntese química , Feromônios/química , Ligação Proteica , Estrutura Secundária de Proteína , Relação Estrutura-AtividadeRESUMO
This review focuses on characteristics of the Type A behavior pattern in women in studies of demographic characteristics, physiological responses, laboratory performance, and personality. With some exceptions, these characteristics parallel those previously described for Type A men. The incidence of Type A behavior in the United States is comparable for men and women when socioeconomic factors are controlled. Type A behavior in women is positively correlated with socioeconomic status, occupation, education, and incidence of coronary heart disease. Type A women tend to show greater autonomic arousal to laboratory stressors as well as greater time urgency and speed, more goal directedness, a preference to work alone under stress conditions, and more competitiveness/aggressiveness than Type B women. Type A positively correlates with various estimates of anger, hostility, and masculine sex role orientation. Depression and anxiety in Type A's are found to vary as a function of sex role orientation and locus of control. Methodological problems in the existing studies are discussed.
Assuntos
Personalidade Tipo A , Mulheres/psicologia , Adolescente , Adulto , Agressão , Nível de Alerta/fisiologia , Atenção , Pressão Sanguínea , Criança , Comportamento Competitivo , Doença das Coronárias/psicologia , Emprego , Feminino , Área de Dependência-Independência , Identidade de Gênero , Objetivos , Frequência Cardíaca , Humanos , Controle Interno-Externo , Masculino , Pessoa de Meia-Idade , Personalidade , Classe SocialRESUMO
PMS (premenstrual syndrome) affects 30-40% of the reproductive female population and hence creates significant impairment amongst women of working age [1]. Having such an economical and financial impact makes it an important disorder to know more about in terms of diagnosis and treatment. In this article, as well as addressing diagnosis and treatments, we focus mainly on peri-menopausal women who are equally (if not more) affected by this disorder and who are subjected to PMS via a host of widely used hormonal treatments. We describe the vicious cycle that exists between exogenous progestogen stimulating PMS-like symptoms and the progestogen that is required for endometrial protection and ways of avoiding this. The treatment should address all concerns of the individual, namely contraceptive requirements, control of PMS and menopausal symptoms. The main theory behind treatment of PMS is to suppress ovulation along the hypothalamo-pituitary-ovarian axis, however neurotransmitters are also implicated in reducing sensitivity to progesterone via receptors, and therefore selective serotonin reuptake inhibitors are also useful. Surgical methods are strongly discouraged and are a last resort. With so many pitfalls, this article aims to tackle the issues commonly encountered with diagnosis and treatment of PMS in the peri-menopause.
Assuntos
Menopausa/fisiologia , Síndrome Pré-Menstrual/diagnóstico , Síndrome Pré-Menstrual/tratamento farmacológico , Feminino , Terapia de Reposição Hormonal , Humanos , Pessoa de Meia-Idade , Síndrome Pré-Menstrual/fisiopatologia , Progestinas/fisiologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêuticoRESUMO
Ninety-seven members of a tinnitus self-help group were asked to list the difficulties that they had as a result of their tinnitus. Seventy-two replies were returned from 22 men and 48 women (sex not reported in two cases) whose average age was 61 years. Tinnitus was associated with hearing difficulties in 53%, effects on lifestyle in 93%, effects on general health in 56%, and emotional difficulties in 70% of the sample. Getting to sleep was the most frequently mentioned difficulty, and many respondents indicated that they experienced depression, annoyance, and insecurity. The clinical application of this open-ended questionnaire are discussed.
Assuntos
Zumbido/psicologia , Adulto , Sintomas Afetivos/etiologia , Idoso , Aconselhamento , Feminino , Nível de Saúde , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Transtornos do Sono-Vigília/etiologia , Inquéritos e Questionários , Zumbido/complicações , Zumbido/terapiaRESUMO
Responses to an open-ended questionnaire were obtained from 250 hearing-aid candidates who had never worn a hearing aid and from 250 experienced hearing-aid users. The questionnaire stated 'Please make a list of the difficulties which you have as a result of your hearing loss.' The responses were divided into six major categories. The hearing-aid candidates reported more problems than the experienced users in the categories of (a) understanding speech where speechreading would normally be used (92% versus 81%), and (b) understanding speech where speechreading would normally not be used (51% versus 43%). A similar number of respondents in both groups reported problems in the categories of (c) personal difficulties (11%), (d) audiological or medical difficulties (18%), and (e) difficulties associated with environmental sounds (34%). Thirty-five per cent of the hearing-aid users reported (f) difficulties associated with their hearing aids. The most frequently reported specific difficulty in both groups was watching television (47% of the candidates and 37% of the users). Twenty-one per cent in each group reported difficulty conversing on the telephone.
Assuntos
Auxiliares de Audição , Perda Auditiva/reabilitação , Adulto , Fatores Etários , Idoso , Feminino , Perda Auditiva/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Ajustamento Social , Percepção da Fala , Fatores de TempoRESUMO
This study used imagery instructions to examine cardiac patients' physiological responses to Type A-relevant situations. Twenty Type A and Type B patients, classified by the Jenkins Activity Survey (JAS), were presented both "Type A" and "Neutral" imagery scripts, followed by the administration of the Structured Interview (SI). Subjects rated each scene for vividness and their emotional reaction to the image. Heart period, pulse transit time, finger temperature, finger pulse volume, frontalis EMG, neck EMG, forearm flexor EMG, and forearm extensor EMG were monitored throughout the experiment. Results showed that (a) Type A's had greater heart period and neck EMG responses to Type A scenes compared to Neutral scenes, (b) Type A's had faster pulse transit times and lower finger temperatures than Type B's throughout the imagery task and the SI, (c) both Type A's and Type B's rated Type A scenes as more emotionally arousing than Neutral scenes, and (d) although the pattern of results was the same when subjects were classified by the SI, results were no longer statistically significant.
Assuntos
Nível de Alerta , Doença das Coronárias/psicologia , Imaginação , Personalidade Tipo A , Nível de Alerta/efeitos dos fármacos , Doença das Coronárias/tratamento farmacológico , Eletromiografia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/psicologia , Testes Psicológicos , Temperatura Cutânea/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacosRESUMO
The Streptococcus gordonii glucosyltransferase structural gene, gtfG, is located immediately downstream from its positive transcriptional regulatory determinant, rgg. Recent genetic studies have indicated that the 3' end of rgg is involved either directly as a binding site or indirectly, e.g. by playing a role in secondary structure, in the interaction of Rgg with the gtfG promoter. A previously identified spontaneous mutant with a point mutation near the 3' end of rgg had only approximately 25% of the parental level of glucosyltransferase activity. To determine if this decreased activity was due to a change in the DNA binding site of trans-acting Rgg, or due to a change in the Rgg protein itself, complementation analyses and DNA-binding studies were performed. In Rgg-deficient strains, the chromosomal rgg point mutation did not influence the ability of plasmid-borne rgg to increase glucosyltransferase expression. However, plasmids carrying parental rgg were able to increase glucosyltransferase activity and expression of a gtfG promoter fusion to a greater extent than plasmids carrying the mutant allele, indicating that the mutant Rgg protein had decreased activity. The ability of NH(2)-terminal (hexahistidine) tagged proteins to bind to a 107 bp dsDNA fragment corresponding to the region immediately upstream of gtfG was demonstrated by surface plasmon resonance. Despite their differences in activity, both mutant and parental recombinant Rgg proteins bound to this dsDNA, albeit with different strengths. These studies provide insights into functional domains of S. gordonii Rgg which influence glucosyltransferase expression, and may have implications for Rgg-like regulatory proteins in related bacteria.
Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/metabolismo , Glucosiltransferases/metabolismo , Mutação Puntual , Streptococcus/metabolismo , Transativadores , Aminoácidos/química , Aminoácidos/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/genética , Regulação Bacteriana da Expressão Gênica , Glucosiltransferases/genética , Plasmídeos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Streptococcus/genética , Streptococcus/crescimento & desenvolvimento , Ressonância de Plasmônio de Superfície , Transcrição GênicaRESUMO
The aim of this study was to investigate the effects of different types of auditory stimulation on reports of auditory hallucinations at the time of the experiment. The results showed that self-reports by seven schizophrenic patients of auditory hallucinations were reduced by different types of auditory stimulation, particularly by listening to pop music. Requiring the subject to read a passage aloud also reduced the levels reported. This study was a replication of one by Margo, Hemsley & Slade (1981) who reported similar findings.
Assuntos
Estimulação Acústica , Alucinações/etiologia , Esquizofrenia/complicações , Adaptação Psicológica , Adulto , Humanos , Masculino , Música , LeituraRESUMO
The present study examined the effects of a footshock reminder in restoring memory after discrete electrical brain stimulation. Rats received low-level bilateral electrical stimulation of either the amygdala or the hippocampus after training in a one-trial passive avoidance task. Rats receiving stimulation showed amnesia when tested 24 hr after training. One hour after the retention test, rats received a footshock reminder cue. Twenty-three hours later, in a second retention test, hippocampus-stimulated animals showed recovery of memory, while amygdala-stimulated rats did not. Stimulated rats that did not receive a reminder footshock remained amnesic. In addition, the effects of amygdala and hippocampal stimulation applied after the footshock reminder cue were examined. On the second retention test, amygdala stimulation disrupted the reminder effect, while hippocampal stimulation had no deleterious effects. The data are interpreted from a memory-attribute point of view which suggests that the amygdala and hippocampus may be differentially involved in the processing of particular attributes of the learning task.
Assuntos
Tonsila do Cerebelo/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Rememoração Mental/fisiologia , Animais , Aprendizagem da Esquiva/fisiologia , Sinais (Psicologia) , Estimulação Elétrica , Masculino , Ratos , Retenção Psicológica/fisiologiaRESUMO
A survey of clinical psychologists determined that both objective and projective tests were used with high frequency. The two tests clinicians most frequently recommended clinical students learn to administer were projective (the Rorschach and the TAT) and, among the 10 most frequently recommended tests, projective tests were recommended approximately 30% more often than objective tests. Clinicians who were frequent test users recommended both objective and projective tests more often than those not using tests. Clinicians doing substantial teaching and research tended to recommend projective tests less often than clinicians not engaged in those activities. Behavior therapists recommended projective tests less often than eclectic, Freudian, and neo-Freudian therapists.
Assuntos
Testes Psicológicos , Psicologia Clínica , Especialização , Humanos , Técnicas Projetivas , Estados UnidosRESUMO
The title compounds, C16H13NO2S, (I), and C21H15NO2S, (II), have similar molecular structures that differ only in the side groups attached to the S atom. The crystal packing is dominated by pi-pi stacking interactions, involving acridinedione-acridinedione overlap in (I) and both acridinedione-acridinedione and acridinedione-tolyl overlap in (II).