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1.
Clin Radiol ; 78(6): 444-450, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37029001

RESUMO

AIM: To evaluate the effectiveness of an ultrafast breast magnetic resonance imaging (MRI) protocol in differentiating benign and malignant breast lesions. MATERIALS AND METHODS: Fifty-four patients with Breast Imaging Reporting and Data System (BI-RADS) 4 or 5 lesions were recruited between July 2020 to May 2021. A standard breast MRI was performed with the inclusion of the ultrafast protocol between the unenhanced sequence and the first contrast-enhanced sequence. Three radiologists performed image interpretation in consensus. Ultrafast kinetic parameters analysed included the maximum slope (MS), time to enhancement (TTE), and arteriovenous index (AVI). These parameters were compared using receiver operating characteristics with p-values of <0.05 considered to indicate statistical significance. RESULTS: Eighty-three histopathological proven lesions from 54 patients (mean age 53.87 years, SD 12.34, range 26-78 years) were analysed. Forty-one per cent (n=34) were benign and 59% (n=49) were malignant. All malignant and 38.2% (n=13) benign lesions were visualised on the ultrafast protocol. Of the malignant lesions, 77.6% (n=53) were invasive ductal carcinoma (IDC) and 18.4% (n=9) were ductal carcinoma in situ (DCIS). The MS for malignant lesions (13.27%/s) were significantly larger than for benign (5.45%/s; p<0.0001). No significant differences were seen for TTE and AVI. The area under the ROC curve (AUC) for the MS, TTE, and AVI were 0.836, 0.647, and 0.684, respectively. Different types of invasive carcinoma had similar MS and TTE. The MS of high-grade DCIS was also similar to that of IDC. Lower MS values were observed for low-grade (5.3%/s) compared to high-grade DCIS (14.8%/s) but the results were not significant statistically. CONCLUSION: The ultrafast protocol showed potential to discriminate between malignant and benign breast lesions with high accuracy using MS.


Assuntos
Carcinoma de Mama in situ , Neoplasias da Mama , Carcinoma Intraductal não Infiltrante , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Feminino , Meios de Contraste , Diagnóstico Diferencial , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos
2.
Hum Reprod ; 36(7): 1907-1921, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34052851

RESUMO

STUDY QUESTION: What is the transcriptome signature associated with poor performance of rescue IVM (rIVM) oocytes and how can we rejuvenate them? SUMMARY ANSWER: The GATA-1/CREB1/WNT signalling axis was repressed in rIVM oocytes, particularly those of poor quality; restoration of this axis may produce more usable rIVM oocytes. WHAT IS KNOWN ALREADY: rIVM aims to produce mature oocytes (MII) for IVF through IVM of immature oocytes collected from stimulated ovaries. It is not popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress and the absence of cumulus cell support in oocytes could account for the failure of rIVM. STUDY DESIGN, SIZE, DURATION: We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo oocytes (IVO) (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors. The effects of maternal age and ovarian responses on rIVM oocyte transcriptomes were also studied. In parallel, we studied the effect of gallic acid on the maturation rate of mouse oocytes cultured in IVM medium with (n = 84) and without (n = 85) gallic acid. PARTICIPANTS/MATERIALS, SETTING, METHODS: Human oocytes were collected from donors aged 28-41 years with a body mass index of <30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analysed. Selected genes in the rIVM versus IVO comparison were validated by quantitative real-time PCR. For the gallic acid study, we collected immature oocytes from 5-month-old mice and studied the effect of 10-µM gallic acid on their maturation rate. MAIN RESULTS AND THE ROLE OF CHANCE: The transcriptome profiles of rIVM/IVO oocytes showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least 2-fold change and adjusted P < 0.05) were found to be enriched in metabolic processes, biosynthesis and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/ß-catenin signalling in rIVM when compared with IVO oocytes. We found that oestradiol levels exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio) for each donor. rIVM oocytes from women with a high MII ratio were found to have over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor clinical outcomes of rIVM, we compared oocytes collected from young donors with a high MII ratio with oocytes from donors of advanced maternal age and lower MII ratio, and revealed that CREB1 is an important regulator. Thus, our study identified that GATA-1/CREB1/WNT signalling was repressed in both rIVM oocytes versus IVO oocytes and in rIVM oocytes of lower versus higher quality. Consequently we investigated gallic acid, as a potential antioxidant substrate in human rIVM medium, and found that it increased the mouse oocyte maturation rate by 31.1%. LARGE SCALE DATA: Raw data from this study can be accessed through GSE158539. LIMITATIONS, REASONS FOR CAUTION: In the rIVM oocytes of the high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle, so polar body extrusion was the only indicator. WIDER IMPLICATIONS OF THE FINDINGS: This study showed that GATA-1/CREB1/WNT signalling was repressed in rIVM oocytes compared with IVO oocytes and was further downregulated in low-quality rIVM oocytes, providing us the foundation of subsequent follow-up research on human oocytes and raising safety concerns about the clinical use of rescued oocytes. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Collaborative Research Fund, Research Grants Council, C4054-16G, and Research Committee Funding (Research Sustainability of Major RGC Funding Schemes), The Chinese University of Hong Kong. The authors have no conflicts of interest to declare.


Assuntos
Oócitos , Indução da Ovulação , Animais , Células do Cúmulo , Feminino , Técnicas de Maturação in Vitro de Oócitos , Camundongos , Oogênese , Análise de Sequência de RNA
3.
Malays J Pathol ; 42(3): 461-467, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33361730

RESUMO

INTRODUCTION: Primary gastrointestinal melanomas are mucosal malignancies that arise from melanocytes in the oropharynx, rectum, and anus. Anorectal malignant melanoma (ARMM) are exceedingly rare, accounting for less than 1% of all melanomas, 0.1% of all rectal malignancies and 4% of anal malignancies. Diagnosis is frequently delayed as these lesions are often mistaken for haemorrhoids. Histological evaluation with special immunohistochemical stains is often necessary for definitive diagnosis. Due to the aggressive nature, 61% of patients with ARMM would already have lymph node involvement or distant metastases, by the time of diagnosis. Prognosis is usually poor with 5-year survival rate of <20%. We report a case of metastatic ARMM in an elderly lady who presented with symptoms and signs mimicking a haemorrhoid. CASE REPORT: A 69-year-old lady presented with one year history of intermittent rectal bleed and an anorectal mass that was initially treated as haemorrhoid. Colonoscopy showed a hyperpigmented mass in the anorectal region which was confirmed as malignant melanoma on histopathological examination. Imaging with CT and MRI demonstrated locally advanced tumour with distant metastases to the liver and lung. Patient was referred for palliative management. CONCLUSION: ARMM is a rare malignancy and often presented with non-specific clinical signs. Diagnosis is frequently delayed without high index of suspicion. MRI pelvis is the imaging of choice to assess local extent of disease. Histologic evaluation with special immunohistochemical stains is often necessary for definitive diagnosis. Prognosis is poor despite surgical and chemotherapeutic interventions.


Assuntos
Neoplasias do Ânus/patologia , Melanoma/patologia , Neoplasias Retais/patologia , Idoso , Feminino , Humanos
4.
J Acoust Soc Am ; 146(3): 1580, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31590498

RESUMO

The acoustical insertion loss of asymmetrical balconies on high-rise buildings was studied experimentally using a 1:3 scaled down model in the present study. Four balcony forms featured by the presence of a full-height side-wall were included. A linear loudspeaker array was adopted as the sound source. The effects of source orientation and balcony elevation angle on the insertion loss and its spectral variation were examined. The position of the full-height side-wall relative to the sound source significantly affects the balcony insertion loss. It is observed that the maximum traffic noise amplification and attenuation are both ∼6 dBA. Results also suggest that the balustrade has no effect on the insertion loss spectral variation pattern, though the insertion loss magnitude could be much reduced without it in the presence of a short side-wall. This short side-wall determines the insertion loss spectral variation pattern. Significant sound amplification is found at frequencies of the odd order transverse modes, the longitudinal modes, and their coupled modes regardless of balcony form and elevation angle. It is also found that the major acoustic mode interactions are basically independent of source orientation for balconies without the short side-wall.

5.
Med J Malaysia ; 74(3): 240-242, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31256183

RESUMO

In central venous obstruction, vertebral marrow enhancement (VME) may be seen secondary to collateral venous flow via the vertebral venous plexus.1 There are only sporadic case reports on pseudolesions due to collateral enhancement mimicking sclerotic osseous metastasis. This abnormal vertebral enhancement may lead to erroneous diagnosis of sclerotic metastases or suspicious bone lesion which affect the management and prognosis. We describe a case of brachiocephalic vein obstruction-related vertebral body pseudolesions as identified in contrast-enhanced computed tomography (CECT) scan.


Assuntos
Veias Braquiocefálicas , Hiperemia/etiologia , Doenças Vasculares Periféricas/complicações , Doenças Vasculares Periféricas/diagnóstico , Estenose Espinal/diagnóstico , Idoso , Constrição Patológica , Diagnóstico Diferencial , Humanos , Masculino
7.
Clin Otolaryngol ; 42(6): 1311-1318, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28317337

RESUMO

OBJECTIVE: To explore the rationale for investigating patients presenting with globus symptoms. In this regard, we also assess the efficacy and safety of transnasal flexible laryngo-oesophagoscopy (TNFLO). METHODS: A prospective study in a head and neck cancer centre of patients with persistent globus symptoms with normal flexible nasoendoscopy/indirect mirror laryngoscopy and failure of first-line medical treatment. The role of TNFLO in investigating these patients was assessed. RESULTS: A total of 218 patients were recruited in this study. Positive findings included upper aerodigestive cancers in two patients, other pathologies included reflux (four patients), cricopharyngeus-related pathologies (19 patients), candida (five patients). There were only five re-referrals of patients who were discharged following normal examination with TNFLO. In nine patients, TNFLO could not be completed and they went on to have other diagnostic procedures CONCLUSION: This article is the largest to date in the UK to assess the role of TNFLO in investigating patients with globus symptoms. TNFLO is equal to rigid endoscopy as a diagnostic tool. However, it is superior in terms of image clarity, ability to record video images and safety.


Assuntos
Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Esofagoscopia , Laringoscopia , Cirurgia Endoscópica por Orifício Natural , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reino Unido , Adulto Jovem
9.
Clin Exp Pharmacol Physiol ; 42(9): 888-895, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26173485

RESUMO

Sympatholytic and vasodilator drugs have been of major therapeutic benefit in patients with heart failure (HF). Urocortin-2 (Ucn2) is a small corticotrophin-related peptide distributed throughout the cardiovascular system which inhibits cardiac sympathetic nerve activity (CSNA) and is also a powerful vasodilator. This study analysed the effects of a 60-min infusion of Ucn2 (25 µg) on muscle sympathetic nerve activity (MSNA) recorded from the lower limb in eight healthy men and four men with stable HF. During Ucn2 infusion, mean arterial pressure fell to a nadir of 84 ± 2 compared to 95 ± 2 mmHg during placebo (P = 0.001) and heart rate increased to a maximum of 74 ± 1 compared to 64 ± 1 b.p.m. (P < 0.001). Total peripheral resistance fell by 23 ± 4% compared with an increase of 23 ± 4% (P < 0.001) and cardiac output increased by 22 ± 4 compared to 4 ± 4% (P = 0.001). The MSNA burst frequency increased by 9 ± 2 compared to 1 ± 2 burst/min (P = 0.005) and burst area/min by 133 ± 7 vs 107 ± 7% (P = 0.01). Burst incidence and baroreflex sensitivity were not significantly altered. Qualitatively similar changes were observed in stable HF patients. Ucn2-induced vasodilatation increased MSNA in humans, as opposed to the decrease in CSNA we observed in sheep. Therefore, if Ucn2 has a central inhibitory effect on MSNA, it was over-run by off-loading the cardiovagal baroreflex. Alternatively, CSNA may be less responsive to baroreflex off-loading than MSNA.

10.
Brain Inj ; 29(12): 1426-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26287759

RESUMO

PRIMARY OBJECTIVE: To assess the relationship between disability, length of stay (LOS) and anticholinergic burden (ACB) with people following acquired brain or spinal cord injury. RESEARCH DESIGN: A retrospective case note review assessed total rehabilitation unit admission. METHODS AND PROCEDURES: Assessment of 52 consecutive patients with acquired brain/spinal injury and neuropathy in an in-patient neuro-rehabilitation unit of a UK university hospital. Data analysed included: Northwick Park Dependency Score (NPDS), Rehabilitation complexity Scale (RCS), Functional Independence Measure and Functional Assessment Measure FIM-FAM (UK version 2.2), LOS and ACB. Outcome was different in RCS, NPDS and FIM-FAM between admission and discharge. MAIN OUTCOMES AND RESULTS: A positive change was reported in ACB results in a positive change in NPDS, with no significant effect on FIM-FAM, either Motor or Cognitive, or on the RCS. Change in ACB correlated to the length of hospital stay (regression correlation = -6.64; SE = 3.89). There was a significant harmful impact of increase in ACB score during hospital stay, from low to high ACB on NPDS (OR = 9.65; 95% CI = 1.36-68.64) and FIM-FAM Total scores (OR = 0.03; 95% CI = 0.002-0.35). CONCLUSIONS: There was a statistically significant correlation of ACB and neuro-disability measures and LOS amongst this patient cohort.


Assuntos
Antagonistas Colinérgicos/farmacologia , Tempo de Internação/tendências , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/fisiopatologia , Lesões Encefálicas/reabilitação , Antagonistas Colinérgicos/efeitos adversos , Pessoas com Deficiência , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde/tendências , Recuperação de Função Fisiológica , Centros de Reabilitação , Estudos Retrospectivos , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação
11.
J Intellect Disabil Res ; 59(7): 678-87, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25400206

RESUMO

BACKGROUND: Children with intellectual disability and specific learning disabilities often lack age-appropriate social skills, which disrupts their social functioning. Because of the limited effectiveness of classroom mainstreaming and social skills training for these children, it is important to explore alternative opportunities for social skill acquisition. Participation in social activities is positively related to children's social adjustment, but little is known about the benefits of activity participation for children with intellectual and specific learning disabilities. METHODS: This study investigated the association between frequency and type of social activity participation and the social competence of 8-11-year-old children with intellectual disability (n = 40) and specific learning disabilities (n = 53), in comparison with typically developing peers (n = 24). RESULTS: More time involved in unstructured activities, but not structured activities, was associated with higher levels of social competence for all children. This association was strongest for children with intellectual disability, suggesting that participation in unstructured social activities was most beneficial for these children. CONCLUSION: Future research on the quality of involvement is necessary to further understand specific aspects of unstructured activities that might facilitate social development.


Assuntos
Desenvolvimento Infantil/fisiologia , Deficiência Intelectual/psicologia , Deficiências da Aprendizagem/psicologia , Participação Social/psicologia , Habilidades Sociais , Criança , Feminino , Humanos , Masculino
12.
Nat Med ; 13(2): 147-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17206149

RESUMO

Poor human-to-human transmission of influenza A H5N1 virus has been attributed to the paucity of putative sialic acid alpha2-3 virus receptors in the epithelium of the human upper respiratory tract, and thus to the presumed inability of the virus to replicate efficiently at this site. We now demonstrate that ex vivo cultures of human nasopharyngeal, adenoid and tonsillar tissues can be infected with H5N1 viruses in spite of an apparent lack of these receptors.


Assuntos
Virus da Influenza A Subtipo H5N1/metabolismo , Influenza Humana/transmissão , Receptores de Superfície Celular/metabolismo , Sistema Respiratório/virologia , Ligação Viral , Células Cultivadas , Epitélio/virologia , Histocitoquímica , Hong Kong , Humanos , Vírus da Influenza A Subtipo H1N1/metabolismo , Vírus da Influenza A Subtipo H3N2/metabolismo , Influenza Humana/metabolismo , Fito-Hemaglutininas/metabolismo , Replicação Viral/fisiologia
13.
Pacing Clin Electrophysiol ; 37(7): 810-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24502608

RESUMO

BACKGROUND: We hypothesized that left atrial pressure (LAP) obtained by a permanent implantable sensor is sensitive to changes in cardiac resynchronization therapy (CRT) settings and could guide CRT optimization to improve the response rate. We investigated the effect of CRT optimization on LAP and its waveform parameters in ambulant heart failure (HF) patients. METHODS: CRT optimization was performed in eight ambulant HF patients, using echocardiography as reference. LAP waveform was acquired at each of eight atrioventricular (AV) intervals and five inter-ventricular (VV) intervals. Selected waveform parameters were also evaluated for their sensitivity to CRT changes and agreement with echocardiography-guided optimal settings. RESULTS: Optimal AV and VV intervals varied considerably between patients. All patients exhibited significant changes in waveform morphology with AV optimization. Optimal AV delay determined from echocardiography ranged between 140 ms and 225 ms. Mean LAP tended to be lower at optimal setting 14 ± 3 mmHg compared to shorter (<100 ms) or longer (>160 ms) AV settings (P = 0.16). There were clear trends to smaller peak a-wave (P = 0.11) and gentler positive a-slope (P = 0.15) and positive v-slope (P = 0.09) with longer AV delays. Mean LAP and negative v-wave slope correlated well with echo-guided optimal setting, r = 0.91 (P = 0.001) and 0.79 (P = 0.03), respectively. No significant effects on LAP or waveform were seen during VV optimization. CONCLUSIONS: LAP and its waveform changes considerably with AV optimization. There is good agreement between echo-guided optimal setting and LAP. LAP could provide an objective guide to CRT optimization. (Clinical Trial Registry information: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00632372).


Assuntos
Pressão Atrial , Terapia de Ressincronização Cardíaca/métodos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Adulto , Idoso , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos
14.
J Intellect Disabil Res ; 57(6): 539-51, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22533573

RESUMO

BACKGROUND: Cortisol is a marker of physiological arousal, exhibiting a characteristic pattern of diurnal activity. The daily cortisol profile has been xamined extensively and is atypical in a number of clinical disorders. However, there are very few studies focussing on the cortisol profile in adults with intellectual disabilities (ID). This paper reports a preliminary investigation into the nature of the cortisol profile in adults with mild or moderate ID and provides reflections on the challenges of psychophysiological research in this population. METHODS: On two consecutive days, 39 adults with mild or moderate ID each donated saliva samples for cortisol analysis, at multiple times between waking and evening. A comparison between these data and the published literature permitted a descriptive assessment of the cortisol awakening response (CAR) and diurnal profile. A variety of psychometric measures and an assessment of behavioural history were also collected in order to describe aspects of the participants' emotional and behavioural states. RESULTS: Individuals with ID exhibit a diurnal cortisol secretion profile, qualitatively similar to that of the typical, healthy, adult population. However, the findings also suggested a blunted CAR, warranting further investigation. There was also some evidence that cortisol secretion was affected by anxiety and a recent history of aggression. CONCLUSION: While further work is required to characterise the CAR fully, there was no indication that the diurnal cortisol profile among people with ID differs from that of the typical population. This study also demonstrates that, although challenging, it is feasible, and acceptable to participants, to collect repeated physiological measures from men and women with mild and moderate ID.


Assuntos
Ritmo Circadiano/fisiologia , Sistema Hipotálamo-Hipofisário/fisiologia , Deficiência Intelectual/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiologia , Adulto , Idoso , Agressão/fisiologia , Ansiedade/fisiopatologia , Emoções/fisiologia , Feminino , Humanos , Hidrocortisona/metabolismo , Deficiência Intelectual/metabolismo , Deficiência Intelectual/psicologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Psicometria , Saliva/metabolismo , Adulto Jovem
15.
Phys Rev Lett ; 108(14): 146102, 2012 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-22540808

RESUMO

We use scanning tunneling microscopy and spectroscopy to measure the energy shift of empty quantum-well (QW) states in Pb islands on the Cu(111) surface. It is found that, with an increase of the electric field, the behavior of the energy shift can be grouped into two different modes for most QW states. In the first mode, the state energy moves toward high energy monotonically. In the second mode, the state energy shifts to a lower energy initially and then turns around to a higher energy. Moreover, we have observed that the QW states of higher energy behave in preference to the first mode, but they gradually change to the second mode as the Pb island becomes thicker. This thickness-dependent behavior reflects the existence of local expansion in the Pb islands, due to the electric field, and that the expansion is larger for a thicker island. QW states can thus be used for studying the localized lattice deformation in the nanometer scale.

16.
J Nanosci Nanotechnol ; 11(3): 2696-9, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449457

RESUMO

Magnetic properties and growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface have been studied by using both surface magneto-optic Kerr effect (SMOKE) and scanning tunneling microscopy (STM), respectively. STM results show that the growth mechanism of ultrathin Co films on Si(111)-7 x 7 surface at room temperature belongs to Stranski-Krastanov (SK) growth mode. Due to formation of CoSi2 layer, no magnetic signal could be detected by SMOKE for 1-4 ML Co deposited on Si(111) surface. Because of rougher surface, both longitudinal and perpendicular magnetic anisotropy configuration appear for 4.2-10 ML Co/Si(111) films. When the Co thickness is increased to 10 ML, only longitudinal anisotropy configuration is found, resulting from the contribution to the volume anisotropy. Furthermore, in-plane coercivity increases with Co coverage because of enhancement of ferromagnetic coupling with Co thickness, out-of-plane coercivity increases with Co coverage due to the increment of demagnetized field, induced by the rougher Co surface and pinhole structures.


Assuntos
Cobalto/química , Cristalização/métodos , Magnetismo , Membranas Artificiais , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Silício/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Propriedades de Superfície
17.
Proc Natl Acad Sci U S A ; 105(31): 10978-83, 2008 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-18678919

RESUMO

Current antipsychotics provide symptomatic relief for patients suffering from schizophrenia and related psychoses; however, their effectiveness is variable and many patients discontinue treatment due to side effects. Although the etiology of schizophrenia is still unclear, a leading hypothesis implicates an imbalanced dopaminergic system. Muscarinic acetylcholine (ACh) receptors regulate dopamine levels in key areas of the brain involved in psychosis, with the M(4) subtype emerging as a key regulator of dopaminergic hyperactivity. Unfortunately, no selective small molecule tools exist to provide pharmacological validation of this hypothesis. Here, we describe the discovery of a small molecule modulator, LY2033298, that is highly selective for human M(4) receptors by virtue of targeting an allosteric site on this receptor. Pharmacological assays confirmed the selectivity of LY2033298 for the M(4) receptor and revealed the highest degree of positive allosteric enhancement of ACh potency thus far identified. Radioligand binding assays also show this compound to directly potentiate agonist binding while having minimal effects on antagonist binding. Mutational analysis identified a key amino acid (D(432)) in the third extracellular loop of the human M(4) receptor to be critical for selectivity and agonist potentiation by LY2033298. Importantly, LY2033298 was active in animal models predictive of clinical antipsychotic drug efficacy indicating its potential use as a first-in-class, selective, allosteric muscarinic antipsychotic agent.


Assuntos
Antipsicóticos/farmacologia , Receptor Muscarínico M4/metabolismo , Esquizofrenia/tratamento farmacológico , Tiofenos/farmacologia , Regulação Alostérica/efeitos dos fármacos , Antipsicóticos/uso terapêutico , Linhagem Celular , Análise Mutacional de DNA , Humanos , Ácidos Nicotínicos/farmacologia , Ensaio Radioligante , Receptor Muscarínico M4/genética , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas
18.
Br J Cancer ; 102(2): 419-27, 2010 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-20051947

RESUMO

BACKGROUND: Testicular germ cell tumour (TGCT) is the most common malignant tumour in young males. Although aberrant DNA methylation is implicated in the pathophysiology of many cancers, only a limited number of genes are known to be epigenetically changed in TGCT. This report documents the genome-wide analysis of differential methylation in an in vitro model culture system. Interesting genes were validated in TGCT patient samples. METHODS: In this study, we used methylated DNA immunoprecipitation (MeDIP) and whole-genome tiling arrays to identify differentially methylated regions (DMRs). RESULTS: We identified 35 208 DMRs. However, only a small number of DMRs mapped to promoters. A genome-wide analysis of gene expression revealed a group of differentially expressed genes that were regulated by DNA methylation. We identified several candidate genes, including APOLD1, PCDH10 and RGAG1, which were dysregulated in TGCT patient samples. Surprisingly, APOLD1 had previously been mapped to the TGCT susceptibility locus at 12p13.1, suggesting that it may be important in TGCT pathogenesis. We also observed aberrant methylation in the loci of some non-coding RNAs (ncRNAs). One of the ncRNAs, hsa-mir-199a, was downregulated in TGCT patient samples, and also in our in vitro model culture system. CONCLUSION: This report is the first application of MeDIP-chip for identifying epigenetically regulated genes and ncRNAs in TGCT. We also demonstrated the function of intergenic and intronic DMRs in the regulation of ncRNAs.


Assuntos
Neoplasias Embrionárias de Células Germinativas/genética , Metilação de DNA , Epigênese Genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genoma , Estudo de Associação Genômica Ampla , Humanos , Imunoprecipitação , Masculino , RNA/genética , Neoplasias Testiculares/genética
19.
J Appl Microbiol ; 109(6): 2087-94, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20854453

RESUMO

AIM: Mutations in rrs [nucleotide (nt) 1401], gyrA gene (codons 90, 91 or 94), tlyA, ethA and thyA genes of Mycobacterium tuberculosis (MTB) were evaluated for their usefulness in predicting treatment outcome of kanamycin (KM), capreomycin (CPM), ofloxacin (OFX), ethionamide (ETH) and para-aminosalicylic acid (PAS). METHODS AND RESULTS: DNA sequence analyses of these genes were performed against 188 MTB isolates obtained from patients put on second-line anti-TB drugs (SLDs) with well-documented clinical history and treatment outcome. Mutations in rrs and gyrA have 100% positive predictive value (PPV) in predicting treatment failure for KM and OFX, while 88·9 and 80% were obtained, respectively, when tlyA and rrs mutations were considered in CPM. For ETH and PAS, the PPV of using ethA and thyA mutations to predict treatment failure was 82·5 and 89·3%, respectively. CONCLUSIONS: Our study demonstrated high specificities of gene mutations in predicting poor treatment outcome; however, further technical advancement is required to make the molecular detection of resistances to other SLDs feasible in clinical laboratories. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to correlate different polymorphisms of major SLD resistance gene markers with predicted treatment outcome, using an international set of well-documented clinical MTB strains.


Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Genes Bacterianos , Marcadores Genéticos , Humanos , Testes de Sensibilidade Microbiana , Mutação , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Análise de Sequência de DNA , Resultado do Tratamento , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia
20.
Appl Microbiol Biotechnol ; 85(4): 985-93, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19568748

RESUMO

Earlier investigations disclose that some plant ribosome-inactivating proteins (RIPs) adversely affect mouse embryonic development. In the present study, a mushroom RIP, namely lyophyllin from Lyophyllum shimeji, was isolated, partially sequenced, and its translation inhibitory activity determined. Its teratogenicity was studied by using a technique entailing microinjection and postimplantation whole-embryo culture. It was found that embryonic abnormalities during the period of organogenesis from E8.5 to E9.5 were induced by lyophyllin at a concentration as low as 50 microg/ml, and when the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities increased in severity. The affected embryonic structures included the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were more resistant. Lyophyllin at a concentration higher than 500 microg/ml also induced forebrain blisters within the cranial mesenchyme. When the abnormal embryos were examined histologically, an increase of cell death was found to be associated with abnormal structures, indicating that cell death may be one of the underlying causes of teratogenicity of the mushroom RIP. This constitutes the first report on the teratogenicity of a mushroom RIP.


Assuntos
Agaricales/química , Desenvolvimento Embrionário/efeitos dos fármacos , Proteínas Fúngicas/toxicidade , Proteínas Inativadoras de Ribossomos/toxicidade , Teratogênicos/toxicidade , Anormalidades Induzidas por Medicamentos , Sequência de Aminoácidos , Animais , Técnicas de Cultura Embrionária , Embrião de Mamíferos , Camundongos , Dados de Sequência Molecular , Inibidores da Síntese de Proteínas/toxicidade
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