RESUMO
Shoulder instability episodes are observed in high-energy injuries, such as seizures. In this case report, we highlight the management of a failed distal tibial allograft procedure for recurrent shoulder instability in a patient with a bony Bankart lesion and epilepsy. The patient was treated with an iliac crest autograft and a proximal humerus osteochondral allograft procedure. To our knowledge, the use of an iliac crest autograft for glenoid bone loss and a proximal humerus osteochondral allograft after several failed shoulder instability procedures in a patient with epilepsy has not been reported.
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Hiatal hernias, protrusions of abdominal viscera through the esophageal hiatus, are classified into four types. Types I and II involve ascent of the stomach without affecting the gastroesophageal junction. Types III and IV involve the gastroesophageal junction. Type IV specifically may have stomach as well as other abdominal organ involvement, such as pancreas or omentum. Among these types, type IV is the most complex and rare form, accounting for only 0.1% of all cases of hiatal hernias. This report presents a case of a type IV hiatal hernia involving the lesser omentum and a significant portion of the stomach in an 86-year-old male cadaver with a history of mediastinal surgery. To our knowledge, this presentation in a cadaver has not previously been reported in the literature. This case highlights classification inconsistencies in the literature, particularly regarding type IV hiatal hernias. It is unclear given the current classification system, whether this presentation would be considered a type III or type IV hiatal hernia as it fits both criteria and there are several interpretations of the criteria of a type IV hiatal hernia. Inconsistencies in the classification system may impede standardization of care. This report highlights the need for a more precise classification system that better accounts for anatomical changes and clinical presentation.
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BACKGROUND AND AIMS: Thiopurine use in inflammatory bowel disease (IBD) is well established for maintenance of disease remission. Approximately 3% of patients with IBD develop thiopurine-induced pancreatitis (TIP) as an idiosyncratic reaction. Patients diagnosed as having TIP are largely considered not to be candidates for future use of this drug. We hypothesize that previous TIP is not an absolute contraindication to retrialing a different thiopurine. METHODS: This case series is a retrospective chart review of those patients with IBD in whom thiopurines were successfully reintroduced following suspected TIP. The patients were all cared for in 2 Australasian pediatric IBD services. Four cases are presented of TIP appropriately related temporally to azathioprine commencement, with no other apparent cause of pancreatitis identified. All of these patients were trialled on 6-mercaptopurine according to clinical need and this was well tolerated in all cases. RESULTS AND CONCLUSIONS: This report is the largest case series to date focusing on the reintroduction of a thiopurine following suspected thiopurine induced pancreatitis. All of the patients had a typical presentation of TIP. This case series should call into question the assumption that suspected TIP is an absolute contraindication for the future use of this class of drug. Cautious reintroduction of a thiopurine, in a controlled setting, should be considered in certain circumstances. The clinical relevance of this option is most marked in patients with complicated disease requiring long-term immunosuppression, in whom other therapies are poorly tolerated or contraindicated.
Assuntos
Azatioprina , Doença de Crohn/tratamento farmacológico , Imunossupressores/uso terapêutico , Mercaptopurina/uso terapêutico , Pancreatite/induzido quimicamente , Adolescente , Azatioprina/efeitos adversos , Azatioprina/uso terapêutico , Criança , Pré-Escolar , Contraindicações , Monitoramento de Medicamentos , Feminino , Humanos , Imunossupressores/efeitos adversos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Masculino , Prontuários Médicos , Mercaptopurina/efeitos adversos , Pancreatite/prevenção & controle , Estudos Retrospectivos , Prevenção SecundáriaRESUMO
We report the hot photoexcited electron transfer across the coaxial interface of a cylindrical core-shell nanowire. Modulation of the transfer rates, manifested as a large tunability of the voltage onset of negative differential resistance and of voltage-current phase, is achieved using three different modes. The coupling of electrostatic gating, incident photon energy, and the incident photon intensity to transfer rates is facilitated by the combined influences of geometric confinement and heterojunction shape on hot-electron transfer, and by electron-electron scattering rates that can be altered by varying the incident photon flux, with evidence of weak electron-phonon scattering. Dynamic manipulation of this transfer rate permits the introduction and control of a continuously adjustable phase delay of up to â¼130° within a single nanometer-scale device element.
RESUMO
We demonstrate that ferroelectric (FE) polarizations oriented along the finite thickness direction in ultrathin films are enhanced by the introduction of extreme curvature, thereby suppressing the finite-size-driven evolution of the FE phase transition temperature T(C). The measured responses within individual nanoshells possess magnitudes nearly three times that for their planar counterparts while exhibiting finite curvature-dependent offsets in FE switching hystereses. In stark contrast to the expected scaling of a depression of T(C) with inverse thickness, results based on modified Landau-Ginzburg model calculations indicate geometric curvature-driven polarization gradients in ultrathin films result in significant increases in T(C).
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The trunks of the brachial plexus typically pass through the interscalene triangle, between the anterior and middle scalene muscles and superior to the first rib. Likewise, the two components of the sciatic nerve, tibial and common fibular nerves, usually join and pass together inferior to the piriformis muscle. We present a cadaver with anatomic variations of both the right brachial plexus-interscalene triangle relationship and the sciatic nerve-piriformis relationship. The right brachial plexus C5 and C6 roots formed the superior trunk as they passed through a bifurcated anterior scalene muscle, while the C7, C8, and T1 roots passed posterior to the anterior scalene. After passing through the left greater sciatic foramen, the sciatic nerve branched into the common fibular and tibial nerves, which passed through and inferior to the piriformis muscle, respectively. The presence of these anatomic variations may predispose individuals to symptomatic nerve entrapments such as thoracic outlet syndrome and piriformis syndrome. This finding is relevant to clinicians performing invasive procedures and diagnosing neurological conditions.
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Diverticulosis involving the entire colon is rare in Western society. During a routine dissection of a 74-year-old Caucasian female cadaver, who died from vascular disease complications, diverticula were observed in the ascending, transverse, and descending colon. A total of 413 diverticula were manually counted. The majority of diverticula arose from the right and transverse colon, which is atypical of the disease in Western society. Histological examination of sections from sample diverticula reveals morphology consistent with pseudodiverticula, suggestive of acquired disease. Pancolonic diverticulosis may be associated with systemic diseases such as collagen disorders, vascular complications, and increased risk of recurrent diverticulitis. This case is an example of a rare manifestation of diverticular disease that is important for clinicians to recognize when evaluating and treating patients with gastrointestinal symptoms.
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BACKGROUND: Scorpion neurotoxins, which bind and modulate sodium channels, have been divided into two groups, the alpha and beta toxins, according to their activities. The beta-toxin class includes the groups of excitatory and depressant toxins, which differ in their mode of action and are highly specific against insects. The three-dimensional structures of several alpha and beta toxins have been determined at high resolution, but no detailed 3D structure of an excitatory toxin has been presented so far. RESULTS: The crystal structure of an anti-insect excitatory toxin from the scorpion Buthotus judaicus, Bj-xtrIT, has been determined at 2.1 A resolution and refined to an R factor of 0.209. The first 59 residues form a closely packed module, structurally similar to the conserved alpha and beta toxins ('long toxins') affecting sodium channels. The last 17 residues form a C-terminal extension not previously seen in scorpion toxins. It comprises a short alpha helix anchored to the N-terminal module by a disulfide bridge and is followed by a highly mobile stretch of seven residues, of which only four are seen in the electron-density map. This mobile peptide covers part of a conserved hydrophobic surface that is thought to be essential for interaction with the channel in several long toxins. CONCLUSIONS: Replacement of the last seven residues by a single glycine abolishes the activity of Bj-xtrIT, strongly suggesting that these residues are intimately involved in the interaction with the channel. Taken together with the partial shielding of the conserved hydrophobic surface and the proximity of the C terminus to an adjacent surface rich in charged residues, it seems likely that the bioactive surface of Bj-xtrIT is formed by residues surrounding the C terminus. The 3D structure and a recently developed expression system for Bj-xtrIT pave the way for identifying the structural determinants involved in the bioactivity and anti-insect specificity of excitatory toxins.
Assuntos
Neurotoxinas/química , Neurotoxinas/metabolismo , Estrutura Secundária de Proteína , Canais de Sódio/metabolismo , Sequência de Aminoácidos , Animais , Cristalografia por Raios X , Processamento de Imagem Assistida por Computador , Proteínas de Insetos , Insetos , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Venenos de Escorpião/química , Escorpiões , Alinhamento de Sequência , Relação Estrutura-Atividade , Propriedades de SuperfícieRESUMO
The traditional arthroscopy technique includes the creation of three ports in order to enable visualization, operation, and arthrocentesis. The aim of this study was to assess an advanced temporomandibular joint (TMJ) arthroscopy technique that requires only a single cannula, through which a one-piece instrument containing a visualization canal, irrigation canal, and a working canal is inserted, as an alternative to the traditional double-puncture technique. This retrospective study assessed eight patients (13 TMJs) with pain and/or limited range of movement that was refractory to conservative therapy, who were treated between June 2015 and December 2015. The temporomandibular joint disorder (TMD) was diagnosed by physical examination and mouth opening measurements. The duration of surgery was recorded and compared to that documented for traditional arthroscopies performed by the same surgeon. Operative single-cannula arthroscopy (OSCA) was performed using a holmium YAG (Ho:YAG) 230µm fibre laser for ablation. The OSCA technique proved effective in improving mouth opening in all patients (mean increase 9.12±1.96mm) and in reducing pain (mean visual analogue scale decrease of 3.25±1.28). The operation time was approximately half that of the traditional technique. The OSCA technique is as efficient as the traditional technique, is simple to learn, and is simpler to execute.
Assuntos
Artroscopia/instrumentação , Cânula , Transtornos da Articulação Temporomandibular/cirurgia , Articulação Temporomandibular/cirurgia , Adulto , Artroscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Retrospectivos , Transtornos da Articulação Temporomandibular/diagnósticoRESUMO
A series of antipicornaviral agents containing piperazinyl moieties was synthesized with the objective of obtaining a compound with a broad spectrum of antirhinovirus activity, high potency (< or = 0.003 microgram/ml), and low cytotoxicity (> or = 30 micrograms/ml). Five compounds of this series were evaluated in detail for efficacy against various HRV serotypes. The agent SDZ 880-061, containing the benzothiazine moiety SDZ 108-075, which is particularly active against HRV14, and the thiazolyl acetic acid ester group of SDZ 89-124, which is potent against HRV1B, indeed has a relatively broad antiviral spectrum. SDZ 880-061 inhibited 85% of 89 HRV serotypes tested at a concentration of < or = 3 micrograms/ml. The 3.0 A resolution X-ray structure of SDZ 880-061 bound to HRV14 has revealed the binding characteristics of this potent compound. It binds in the same pocket as other capsid-binding antiviral agents characterized to date, leaving the innermost portion of the pocket vacant. The binding causes similar, although less extensive, alterations of the HRV14 VP1 backbone conformation (residues 100 to 110, 151 to 159, and 213 to 224) compared to other antiviral agents analyzed structurally. Although the contacts between SDZ 880-061 and HRV14 are mostly of hydrophobic character, the inhibitor has three relatively short polar interactions with residues of VP1 that represent potential hydrogen bonds. The amount of solvent-accessible surface area of SDZ 880-061 buried in the complex (613 A2) is within the range of that observed in protein-protein interfaces. The observed influence of time of addition or removal of SDZ 880-061 on virus yield and on the infectious-center formation indicates that the compound primarily interferes with HRV14 cellular attachment. Since it is assumed that uncoating requires virion instability and/or flexibility, the finding that SDZ 880-061 has only a marginal effect on uncoating may be due to the fact that it does not completely fill the hydrophobic pocket.
Assuntos
Antivirais/química , Antivirais/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Rhinovirus/efeitos dos fármacos , Tiazinas/química , Tiazinas/farmacologia , Antivirais/síntese química , Capsídeo/química , Capsídeo/efeitos dos fármacos , Capsídeo/metabolismo , Cristalização , Cristalografia por Raios X , Células HeLa/virologia , Humanos , Imidazóis/química , Imidazóis/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Piperazina , Piperazinas/metabolismo , Piridazinas/química , Piridazinas/farmacologia , Piridinas/química , Piridinas/farmacologia , Rhinovirus/metabolismo , Tiazinas/metabolismo , Fatores de Tempo , Replicação Viral/efeitos dos fármacosRESUMO
The field of proteinomimetics utilizes peptide-based molecules to mimic native protein functions. We describe a novel general method for mimicking proteins by small cyclic peptides for the purpose of drug design, and demonstrate its applicability on bovine pancreatic trypsin inhibitor (BPTI). These unique cyclic peptides, which both embody discontinuous residues of proteins in their bio-active conformation and ensure an induced fit, may overcome some of the pharmacological drawbacks attributed to proteins and peptides. This method, which we call the backbone cyclic (BC) proteinomimetic approach, combines backbone cyclization of peptides with a suitable selection method, cycloscan. Following this procedure, we have prepared a bicyclic nonapeptide, which mimics the binding region of BPTI. The X-ray crystal structure of the complex trypsin:mimetic, as well as kinetic studies, show that the BPTI mimetic binds to the specificity pocket of trypsin in a similar manner to BPTI. Inhibition measurements of various constructs revealed that backbone cyclization imposed the conformation crucial to binding.
Assuntos
Aprotinina/análogos & derivados , Peptídeos Cíclicos/química , Tripsina/química , Animais , Benzoilarginina Nitroanilida/metabolismo , Sítios de Ligação , Bovinos , Cristalografia por Raios X , Desenho de Fármacos , Inibidores Enzimáticos/química , Cinética , Modelos Moleculares , Biblioteca de Peptídeos , Ligação Proteica , Conformação ProteicaRESUMO
The X-ray crystallographic structure of nucleoside diphosphate (NDP) kinase from Myxococcus xanthus has been determined using multiple isomorphous replacement techniques and refined at 2.0 A resolution to a crystallographic R-factor of 0.17. This is the first report of the structure of an enzymatically active NDP kinase and of the enzyme with a bound nucleotide. The structure has been determined in P4(3)2(1)2 and I222 crystal forms. The enzyme monomer consists of a four-stranded antiparallel beta-sheet. The surfaces of the sheet are partially covered with five helical segments. There are two protein molecules in the asymmetric unit of the tetragonal crystal form. They form a dimer with an extensive interface in which 1092 A2 per monomer is buried. The majority of the contact area in the dimer interface is between hydrophobic or aromatic residues. Two dimers are related by a crystallographic 2-fold axis to yield a tetramer. This tetramer is also present in the orthorhombic crystals; however, in this case, the 222 symmetry is entirely crystallographic. Upon tetramer formation, an additional 473 A2 of solvent-accessible surface area from each monomer becomes buried. The interface between dimers in the tetramer is stabilized by salt bridges. Equilibrium sedimentation studies are consistent with the enzyme being a tetramer in solution. The structure of a complex of adenosine diphosphate (ADP) with the enzyme was determined and reveals that most of the nucleotide interactions with the protein are with the pyrophosphate and ribose groups, while the base has no hydrogen bonds with the protein and interacts only by stacking with the side chain of Phe59. The Mg2+ interacts with the pyrophosphate of the ADP and via a solvent molecule with the side chain of the conserved Asp120 residue. The mode of interaction with the nucleotide is novel, with the nucleotide binding at the side of the beta-sheet. The structures of the nucleotide in crystals grown in the presence or absence of Mg2+ are essentially identical. In addition, the phosphotransfer reaction from adenosine triphosphate (ATP) to the enzyme can occur without Mg2+. This suggests that only the second step of the reaction in which the enzyme transfers the phosphate to a nucleoside diphosphate acceptor is significantly catalyzed by the metal.
Assuntos
Myxococcus xanthus/enzimologia , Núcleosídeo-Difosfato Quinase/ultraestrutura , Difosfato de Adenosina/química , Sequência de Aminoácidos , Cristalografia por Raios X , Ligação de Hidrogênio , Substâncias Macromoleculares , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas RecombinantesRESUMO
SCH 38057 (1-[6-(2-chloro-4-methoxyphenoxy)-hexyl]imidazole hydrochloride) is a new, water-soluble antiviral compound that has inhibitory activities against a number of picornavirus infections. The structure of the human rhinovirus 14 (HRV14) complex with SCH 38057 was determined at 3.0 A resolution by single-crystal diffraction techniques using synchrotron X-radiation. SCH 38057 was found to bind at the innermost end of the hydrophobic pocket within the capsid protein VP1, a locus of binding of other antipicornaviral agents; however, the complex differs from previously reported complexes in two important aspects. It leaves a considerable volume near the entrance to the binding pocket unoccupied. In addition, the alterations in the conformation of the VP1 polypeptide are similar to, but more extensive than those observed in HRV14 complexes with other antiviral agents. Although only 9 amino acids of VP1 have close contacts with the SCH 38057 molecule (within 3.6 A), at least 36 amino acids from both VP1 and VP3 have significantly altered conformations (C alpha movement > 0.5 A versus native). The structures of complexes of HRV14 with SCH 38057 and WIN 51711 are compared. Aromatic ring interactions between picornavirus capsid residues and antiviral inhibitors are proposed to be among the major determinants for positioning of these compounds.
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Antivirais/química , Imidazóis/química , Rhinovirus/química , Antivirais/metabolismo , Antivirais/farmacologia , Capsídeo/química , Capsídeo/metabolismo , Simulação por Computador , Elétrons , Humanos , Imidazóis/metabolismo , Modelos Moleculares , Estrutura Molecular , Conformação Proteica , Rhinovirus/efeitos dos fármacos , Rhinovirus/metabolismo , Difração de Raios XRESUMO
The brain metabolic pattern of patients with winter seasonal affective disorder with and without light treatment was determined by positron emission tomography. Compared with controls, patients with seasonal affective disorder with and without light treatment had globally lower metabolic rates, relatively lower superior medial frontal cortex rates, and somewhat higher basal ganglia rates. Patients receiving light treatment had a relatively higher rate in an occipital region of interest containing the primary visual cortex. Patients without light treatment had relatively higher metabolic rates in right parietal and medial orbitofrontal cortex and lower rates in the left parietal cortex. Patients not receiving light treatment had a hemispheric metabolic asymmetry (left greater than right) for the midprefrontal cortex located 67 mm above the canthomeatal line. The right side of this region, previously found reduced in manic-depressive illness and schizophrenia, was decreased primarily in patients with seasonal affective disorder with fewer atypical depressive symptoms. These "abnormal" prefrontal and parietal cortex regions appeared highly "coupled" in the patients with seasonal affective disorder.
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Encéfalo/metabolismo , Glucose/metabolismo , Transtorno Afetivo Sazonal/metabolismo , Adulto , Transtorno Bipolar/metabolismo , Transtorno Bipolar/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Córtex Cerebral/metabolismo , Desoxiglucose/análogos & derivados , Desoxiglucose/metabolismo , Transtorno Depressivo/metabolismo , Transtorno Depressivo/fisiopatologia , Feminino , Fluordesoxiglucose F18 , Lateralidade Funcional , Humanos , Sistema Límbico/metabolismo , Masculino , Pessoa de Meia-Idade , Fototerapia , Transtorno Afetivo Sazonal/fisiopatologia , Transtorno Afetivo Sazonal/terapia , Tomografia Computadorizada de EmissãoRESUMO
BACKGROUND: Multiple lines of evidence suggest that brain serotonergic systems may be disturbed in seasonal affective disorder (SAD). Previously, we found that the serotonergic agent meta-chlorophenylpiperazine (m-CPP) produced increases in activation and euphoria in depressed patients with SAD, but not in patients with SAD following light treatment or in the summer, nor in healthy control subjects in any condition. In the present study, we attempted to replicate and extend this finding using better methods. METHODS: Seventeen outpatients with SAD and 15 control subjects underwent successive 3-week periods of bright light treatment and light avoidance in a randomized order. During the third week of each condition, on 2 different occasions, subjects were admitted to the hospital for a night of sleep (core temperatures were recorded), followed by infusions of m-CPP (0.08 mg/kg) or placebo the next morning. Dependent measures included the 24-item National Institute of Mental Health Self-Rating Scale, plasma corticotropin, cortisol, prolactin, growth hormone, and norepinephrine concentrations, and core temperatures. RESULTS: Meta-chlorophenylpiperazine produced (1) significant increases in "activation-euphoria" ratings only in depressed patients with SAD in the untreated condition and (2) blunted corticotropin and norepinephrine responses in patients with SAD compared with controls across both light treatment conditions. In both groups, light treatment was associated with significant reductions in nocturnal core temperatures, which were correlated with similarly significant reductions in mean diurnal growth hormone concentrations. In patients with SAD, (1) the reductions in nocturnal core temperatures also were correlated with the reductions in baseline depression ratings and (2) the reductions in mean growth hormone concentrations were significantly smaller compared with controls. CONCLUSIONS: The abnormal m-CPP-induced activation-euphoria responses represent a replicated state marker of winter depression in patients with SAD. The blunted m-CPP-induced responsiveness of the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system may represent traitlike abnormalities. The improvements in mood following light treatment in patients with SAD seem to be associated with the lowering of nocturnal core temperatures. The findings, although not easily explained based on a uniform abnormality of serotonin receptors, are nonetheless compatible with the notion that selected regions of the central nervous system are deficient in serotonin transmission during winter depression.
Assuntos
Fototerapia , Piperazinas , Transtorno Afetivo Sazonal/fisiopatologia , Transtorno Afetivo Sazonal/terapia , Agonistas do Receptor de Serotonina , Serotonina/fisiologia , Hormônio Adrenocorticotrópico/sangue , Assistência Ambulatorial , Biomarcadores , Temperatura Corporal , Ritmo Circadiano , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Norepinefrina/sangue , Piperazinas/farmacologia , Prolactina/sangue , Transtorno Afetivo Sazonal/sangue , Estações do Ano , Agonistas do Receptor de Serotonina/farmacologiaRESUMO
BACKGROUND: The cognitive, behavioral, and mood effects of N-methyl-D-aspartate (NMDA) receptor antagonists, such as phencyclidine and ketamine, have been used to study the effects of NMDA receptor dysfunction. Pharmacological modulation of the effects of NMDA receptor antagonists, such as ketamine, may lead to development of novel therapeutic agents for psychiatric illnesses such as schizophrenia. Preclinical studies indicate that some ketamine effects may be mediated through increased glutamate release. In this study, we tested the hypothesis that lamotrigine, a drug reported to inhibit glutamate release, will reduce the neuropsychiatric effects of ketamine in humans. METHOD: Healthy subjects (n = 16) completed 4 test days involving the administration of lamotrigine, 300 mg by mouth, or placebo 2 hours prior to administration of ketamine (0.26 mg/kg by intravenous bolus and 0.65 mg/kg per hour by intravenous infusion) or placebo in a randomized order under double-blind conditions. Behavioral and cognitive assessments were performed at baseline and after administration of the medications. RESULTS: Lamotrigine significantly decreased ketamine-induced perceptual abnormalities as assessed by the Clinician-Administered Dissociative States Scale (P<.001); positive symptoms of schizophrenia as assessed by the Brief Psychiatric Rating Scale positive symptoms subscale (P<.001); negative symptoms as assessed by the Brief Psychiatric Rating Scale negative symptoms subscale (P<.05); and learning and memory impairment as assessed by the Hopkins Verbal Learning Test (P<.05). However, lamotrigine increased the immediate mood-elevating effects of ketamine (P<.05). CONCLUSIONS: Glutamate release-inhibiting drugs may reduce the hyperglutamatergic consequences of NMDA receptor dysfunction implicated in the pathophysiologic processes of neuropsychiatric illnesses such as schizophrenia. Further study is needed.
Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Ketamina/farmacologia , Transtornos Mentais/induzido quimicamente , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Triazinas/farmacologia , Adulto , Afeto/efeitos dos fármacos , Escalas de Graduação Psiquiátrica Breve/estatística & dados numéricos , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/prevenção & controle , Método Duplo-Cego , Feminino , Glutamatos/metabolismo , Glutamatos/fisiologia , Humanos , Ketamina/antagonistas & inibidores , Lamotrigina , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/prevenção & controle , Transtornos da Percepção/induzido quimicamente , Transtornos da Percepção/diagnóstico , Transtornos da Percepção/prevenção & controle , Placebos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Aprendizagem Verbal/efeitos dos fármacosRESUMO
BACKGROUND: Although state-related alterations in catecholamine function have been well-described in depressed subjects, enduring abnormalities have been less reliably identified. In our study, medication-free subjects with fully remitted major depression underwent a paradigm of catecholamine depletion, via use of the tyrosine hydroxylase inhibitor alpha-methylparatyrosine. METHOD: Subjects underwent 2 sets of testing conditions in a double-blind, random-ordered, crossover design, approximately 1 week apart. They underwent active catecholamine depletion (via oral administration of 5 g alpha-methylparatyrosine) or sedation-controlled, sham catecholamine depletion (via oral administration of 250 mg diphenhydramine hydrochloride), during a 2-day observation. Serial mood ratings and blood samples were obtained. RESULTS: Fourteen subjects completed the active testing condition; 13 completed sham testing. Subjects experienced marked, transient increases in core depressive and anxiety symptoms, as demonstrated by a mean 21-point increase on Hamilton Depression Rating Scale scores. Furthermore, 10 (71%) of 14 subjects fulfilled relapse criteria during active testing, whereas 1 (8%) of 13 subjects did so during sham testing. The severity of the depressive reaction correlated with baseline plasma cortisol levels (r = 0.59; P =.04). CONCLUSIONS: Euthymic, medication-free subjects with a history of major depression demonstrate significant depressive symptoms when undergoing testing with alpha-methylparatyrosine. This depressive reaction may represent a reliable marker for a history of depression. Further work is needed to clarify the significance of this finding.
Assuntos
Catecolaminas/metabolismo , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/genética , Inibidores Enzimáticos , alfa-Metiltirosina , Adulto , Catecolaminas/sangue , Catecolaminas/deficiência , Estudos Cross-Over , Transtorno Depressivo/induzido quimicamente , Método Duplo-Cego , Inibidores Enzimáticos/farmacologia , Feminino , Marcadores Genéticos , Ácido Homovanílico/sangue , Humanos , Masculino , Metoxi-Hidroxifenilglicol/sangue , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Recidiva , Índice de Gravidade de Doença , alfa-Metiltirosina/farmacologiaRESUMO
Previous studies indicate that the gaseous messenger carbon monoxide (CO) is released from the eye into the ophthalmic venous blood depending on the intensity of sunlight. This study was designed to determine whether the increased concentration of CO in ophthalmic venous blood affects the synthesis of melatonin and therefore, whether CO released from the eye under normal lighting conditions can be a carrier of light intensity information. Thirty six mature male wild boar and pig crossbreeds (n = 36) were studied. We measured the difference in the scotophase melatonin pathway response in terms of mean concentration of increased melatonin levels after 48 hours infusion of autologous blood plasma with an experimentally induced approximately 3-fold increase in the concentration of CO into the ophthalmic venous sinus. We demonstrated in this crossbreed a marked variation in the duration and amplitude of nocturnal melatonin peak in response to increased concentration of CO in ophthalmic venous blood. During the winter this treatment limited the nocturnal melatonin rise. During the summer this same experimental treatment enhanced the nocturnal melatonin rise. Changes in melatonin levels were always associated with parallel changes in AANAT protein levels. This work demonstrates that non-physiological changes in CO concentration in ophthalmic venous blood can have an acute impact on the systemic melatonin level. These results support humoral phototransduction as a mechanism for some of bright light's effects in animal chronobiology and treatment of winter seasonal affective disorder.
Assuntos
Monóxido de Carbono/farmacologia , Seio Cavernoso/metabolismo , Melatonina/biossíntese , Acetilserotonina O-Metiltransferasa/metabolismo , Animais , Arilalquilamina N-Acetiltransferase/metabolismo , Transfusão de Sangue Autóloga , Monóxido de Carbono/administração & dosagem , Ritmo Circadiano/efeitos dos fármacos , Olho/metabolismo , Luz , Masculino , Fotoperíodo , Glândula Pineal/metabolismo , Plasma/química , Estações do Ano , Sus scrofa , SuínosRESUMO
Fifty patients with absorptive hypercalciuria (AH), 25 normal subjects (NS), and 25 nonhypercalciuric patients with stone disease (NHSF) were studied using an oral calcium tolerance test and 24-h urine collections on both a restricted and an unrestricted calcium intake. Mean (+/- SD) fasting fractional calcium excretion was increased in the patients with AH (2.7 +/- 1.1% vs. 1.4 +/- 0.6% in the NS; P less than 0.001) and was negatively correlated with fasting nephrogenous cAMP, suggesting that this renal calcium leak was secondary to parathyroid suppression. Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] was elevated in 80% of patients with AH and was high normal in the remaining 20%. Ten patients, selected on the basis of results for 1,25-(OH)2D greater than 4 SD from the normal mean, displayed a particularly severe pattern of abnormalities, including mild hypercalcemia in two patients. Pooled data from the NS and patients with AH revealed a significant negative correlation between the plasma concentration of 1,25-(OH)2D and the renal phosphate threshold (r = -0.40; P less than 0.001), but this correlation lost significance when the NHSF were substituted for the NS as a control group (r = -0.07; P = NS). These findings 1) provide a pathophysiological basis for the increase in fasting calcium excretion commonly observed in hypercalciuric patients, and 2) stress the importance of circulating 1,25-(OH)2D in the pathogenesis of the syndrome, but 3) fail to support the phosphate leak theory of pathogenesis.
Assuntos
Cálcio/urina , Fosfatos/metabolismo , Adulto , Calcitriol/sangue , Distúrbios do Metabolismo do Cálcio/metabolismo , Distúrbios do Metabolismo do Cálcio/fisiopatologia , Jejum , Feminino , Humanos , Cálculos Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/fisiopatologiaRESUMO
BACKGROUND: The mechanism by which visible light stimulates chronobiological phase-shifting or antidepressant effects in humans is unknown. METHODS: Normal human NIH/3T3 nonpigmented fibroblasts were irradiated with a visible light source (SunRay) used in the treatment of winter seasonal depression. Electron spin resonance was assessed before and after 10 min of illumination at 2 mW/cm(2) (illuminance of 3700 lux), with and without the presence of 5 microL of 0.0214 mg/mL vitamin C. RESULTS: The fibroblasts showed evidence of production of reactive oxygen species after 10 min of irradiation. CONCLUSIONS: These in vitro data establish that an antidepressant source of visible light is capable of inducing the production of reactive oxygen species in skin. Such species may participate in signal transduction pathways leading to mood changes.