Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
BMC Cancer ; 23(1): 699, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37495988

RESUMO

Drug resistance is a major cause of the inefficacy of conventional cancer therapies, and often accompanied by severe side effects. Thus, there is an urgent need to develop novel drugs with low cytotoxicity, high selectivity and minimal acquired chemical resistance. Peptide-based drugs (less than 0.5 kDa) have emerged as a potential approach to address these issues due to their high specificity and potent anticancer activity. In this study, we developed a support vector machine model (SVM) to detect the potential anticancer properties of novel peptides by scanning the American University in Cairo (AUC) Red Sea metagenomics library. We identified a novel 37-mer antimicrobial peptide through SVM pipeline analysis and characterized its anticancer potential through in silico cross-examination. The peptide sequence was further modified to enhance its anticancer activity, analyzed for gene ontology, and subsequently synthesized. To evaluate the anticancer properties of the modified 37-mer peptide, we assessed its effect on the viability and morphology of SNU449, HepG2, SKOV3, and HeLa cells, using an MTT assay. Additionally, we evaluated the migration capabilities of SNU449 and SKOV3 cells using a scratch-wound healing assay. The targeted selectivity of the modified peptide was examined by evaluating its hemolytic activity on human erythrocytes. Treatment with the peptide significantly reduced cell viability and had a critical impact on the morphology of hepatocellular carcinoma (SNU449 and HepG2), and ovarian cancer (SKOV3) cells, with a marginal effect on cervical cancer cell lines (HeLa). The viability of a human fibroblast cell line (1Br-hTERT) was also significantly reduced by peptide treatment, as were the proliferation and migration abilities of SNU449 and SKOV3 cells. The annexin V assay revealed programmed cell death (apoptosis) as one of the potential cellular death pathways in SNU449 cells upon peptide treatment. Finally, the peptide exhibited antimicrobial effects on both gram-positive and gram-negative bacterial strains. The findings presented here suggest the potential of our novel peptide as a potent anticancer and antimicrobial agent.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Antineoplásicos , Feminino , Humanos , Células HeLa , Linhagem Celular Tumoral , Oceano Índico , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Apoptose , Proliferação de Células
2.
Plast Reconstr Surg ; 145(5): 1252-1261, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32332549

RESUMO

BACKGROUND: Because auricular reconstruction is a complex and relatively uncommon procedure, there are many patients that have had disappointing reconstructions. This study describes the authors' large experience with secondary procedures in patients with unsatisfactory or failed initial ear reconstruction. METHODS: A prospectively maintained database of all consecutive patients who underwent secondary total ear reconstruction from March of 1991 to December of 2017 was reviewed. Demographic data and outcomes were assessed. Patients with acquired absence of the ear were not included. RESULTS: There were 144 microtia patients that met the inclusion criteria. Patient age at the time of the secondary reconstruction ranged from 3 to 59 years. Follow-up duration ranged from 1 to 21 years. Primary reconstruction was performed with rib cartilage in 91 patients, porous polyethylene implant in 47 patients, prosthesis in four patients, and irradiated cadaver rib cartilage in two patients. All secondary reconstructions were performed with porous polyethylene implants. The alloplastic framework was covered with a temporoparietal fascia flap in 76 patients, an occipital fascia flap in 64 patients, and a free fascia flap in four patients (two radial forearm flaps in the same patient, one contralateral temporoparietal fascia flap, and one lateral arm flap). Fourteen patients (10 percent) had complications requiring revision surgery. Secondary surgery was successful in all but one patient. CONCLUSIONS: These data represent the largest series of secondary total ear reconstructions. The use of a porous polyethylene implant is an ideal method for these patients because of its minimal morbidity and relatively low complication rate. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.


Assuntos
Microtia Congênita/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Complicações Pós-Operatórias/epidemiologia , Reoperação/métodos , Terapia de Salvação/métodos , Adolescente , Adulto , Cartilagem/transplante , Criança , Pré-Escolar , Pavilhão Auricular/anormalidades , Pavilhão Auricular/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Polietileno , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Próteses e Implantes , Procedimentos de Cirurgia Plástica/efeitos adversos , Procedimentos de Cirurgia Plástica/instrumentação , Procedimentos de Cirurgia Plástica/estatística & dados numéricos , Reoperação/efeitos adversos , Reoperação/instrumentação , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Terapia de Salvação/efeitos adversos , Terapia de Salvação/instrumentação , Terapia de Salvação/estatística & dados numéricos , Retalhos Cirúrgicos/efeitos adversos , Retalhos Cirúrgicos/transplante , Transplante Autólogo/efeitos adversos , Transplante Autólogo/métodos , Transplante Autólogo/estatística & dados numéricos , Resultado do Tratamento , Adulto Jovem
3.
Osteoporos Int ; 29(7): 1601-1608, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29619542

RESUMO

Humeral fractures are not well understood and thus we examined the incidence and outcomes of elderly humeral fractures at a single institution over a 3-year period. We found increasing incidence in humeral fractures with increasing age and negative outcomes comparable to hip fractures. INTRODUCTION: In this study, we report the incidence of humeral fractures in the older patient and their outcomes, including new nursing homes discharges and mortality, residing in the metropolitan referral area of a Sydney tertiary referral hospital. METHODS: All admissions between 2013 and 2016, of patients aged 65 years or more, presenting to hospital with humeral fractures were reviewed. The data was explored primarily for outcomes (mortality and new admissions to residential aged care facility) and secondarily for clinical association with humeral fractures. RESULTS: Two hundred eighty-one episodes of humeral fracture were identified. Incidence peaked in the above 85-year-old group at 670 per 100,000 persons per year. Proximal fractures were accounted for 84.3% of the cohort. 12.8% received operative management. The in-hospital mortality rate was 3.6%. Gender was a significant predictor for mortality (OR = 5.8, 95% CI 1.3-28.5, p value = 0.0032) with males six times more likely to experience in-hospital mortality compared to females. 17.8% of participants were admitted to a new nursing home. Logistical regression demonstrated age (OR = 1.10, 95% CI 1.04-1.17; p value = 0.001) and Charlson comorbidity index (OR = 1.32, 95% CI 1.04-1.66; p value = 0.02) were predictors of admission to a new nursing home. CONCLUSION: Humeral fractures are common in the older population and cause a substantial amount of new nursing home admissions and mortality. Further study is required to ascertain appropriate guidelines for treatment and rehabilitation.


Assuntos
Fraturas do Úmero/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Humanos , Fraturas do Úmero/reabilitação , Incidência , Tempo de Internação/estatística & dados numéricos , Masculino , New South Wales/epidemiologia , Casas de Saúde/estatística & dados numéricos , Admissão do Paciente/estatística & dados numéricos , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais
4.
J Laryngol Otol ; 127(5): 473-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23552210

RESUMO

BACKGROUND: Vestibular schwannomas are benign tumours which usually originate from the vestibular portion of the VIIIth cranial nerve. Treatment options include observation with serial imaging, stereotactic radiation and microsurgical removal. AIM: The goal of surgery was complete eradication of tumour with preservation of hearing and facial nerve function. METHODS: A retrospective review was undertaken of 24 cases of vestibular schwannoma jointly operated upon by a team of neurosurgeons and otologists at the Suez Canal University Hospital, with assessment of VIIth and VIIIth cranial nerve function, tumour size, and extent of growth. All surgery utilised a retromastoid, suboccipital approach. RESULTS: Complete tumour removal was achieved in 19 patients. Anatomical preservation of the facial nerve was possible in 66.6 per cent of patients. Pre-operative, useful hearing was present in four patients, and preserved in 80 per cent. Cerebrospinal fluid leakage was diagnosed in two (8.3 per cent) patients, who responded to conservative therapy. CONCLUSION: The retromastoid, suboccipital surgical approach to the skull base can be safely and successfully achieved using a microsurgical technique, with minimal or no damage to neurovascular structures, even for large tumours.


Assuntos
Face/fisiologia , Audição , Neuroma Acústico/cirurgia , Adolescente , Adulto , Feminino , Humanos , Masculino , Microcirurgia , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Otológicos/efeitos adversos , Procedimentos Cirúrgicos Otológicos/métodos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Adulto Jovem
5.
J Laryngol Otol ; 124(10): 1061-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20537205

RESUMO

INTRODUCTION: Halofantrine is a newly developed antimalarial drug used for the treatment of Plasmodium falciparum malaria. The introduction of this drug has been delayed because of its possible side effects, and due to insufficient studies on adverse reactions in humans. There have been no studies investigating its effect on hearing. METHODS: Thirty guinea pigs were divided into three groups: a control group, a halofantrine therapeutic dose group and a halofantrine double therapeutic dose group. One cochlea specimen from each animal was stained with haematoxylin and eosin and the other with toluidine blue. RESULTS: No changes were detected in the control group. The halofantrine therapeutic dose group showed loss and distortion of inner hair cells and inner phalangeal cells, and loss of spiral ganglia cells. In the halofantrine double therapeutic dose group, the inner and outer hair cells were distorted and there was loss of spiral ganglia cells. CONCLUSION: Halofantrine has mild to moderate pathological effects on cochlea histology, and can be considered an ototoxic drug.


Assuntos
Antimaláricos/toxicidade , Cóclea/efeitos dos fármacos , Fenantrenos/toxicidade , Animais , Cóclea/patologia , Relação Dose-Resposta a Droga , Cobaias , Células Ciliadas Auditivas Externas/efeitos dos fármacos , Coloração e Rotulagem/métodos
6.
AMIA Annu Symp Proc ; : 1178, 2008 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-18999145

RESUMO

In critically ill patients control of blood sugar levels with IV insulin has been shown to improve clinical outcomes in the intensive care units. We have developed an analytical framework with which to evaluate and compare IV insulin-treatment models and protocols. Performance of the analytical framework is demonstrated using protocols published by others and new protocols under development by our group.


Assuntos
Cuidados Críticos/métodos , Estado Terminal/terapia , Sistemas de Apoio a Decisões Clínicas , Quimioterapia Assistida por Computador/métodos , Hiperglicemia/tratamento farmacológico , Insulina/administração & dosagem , Sistemas Computadorizados de Registros Médicos , Avaliação de Resultados em Cuidados de Saúde/métodos , Humanos , Injeções Intravenosas , Resultado do Tratamento , Utah
7.
AMIA Annu Symp Proc ; : 1180, 2008 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-18999166

RESUMO

Constantly changing diabetes care standards makes it challenging to deliver care adapted to the unique condition of the individual patient. The availability of large amounts of data from patient's electronic medical records makes it possible to individualize diabetes management. Initial design of a "patient-specific" hybrid system (physiological-causal probabilistic) of adaptive diabetes models and insulin treatment algorithms will be presented. The system is uniquely derived and tested using a diabetes data mart of about 33,000 patients.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Diabetes Mellitus/tratamento farmacológico , Quimioterapia Assistida por Computador/métodos , Insulina/uso terapêutico , Sistemas Computadorizados de Registros Médicos/estatística & dados numéricos , Medicina de Precisão/métodos , Assistência Centrada no Paciente/métodos , Utah
8.
Photochem Photobiol Sci ; 7(7): 844-53, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18597033

RESUMO

The interaction of blepharismin (BP) and oxyblepharismin (OxyBP) with bovine alpha-crystallin (BAC) has been studied both by steady-state and femtosecond spectroscopy, with the aim of assessing the possible phototoxicity of these compounds toward the eye tissues. We showed that these pigments form with BAC potentially harmful ground-state complexes, the dissociation constants of which have been estimated to be 6 +/- 2 micromol L(-1) for OxyBP and 9 +/- 4 micromol L(-1) for BP. Irradiation with steady-state visible light of solutions of blepharismins in the presence of BAC proved to induce a quenching of both the pigment and the intrinsic protein fluorescences. These effects were tentatively rationalized in terms of structural changes of alpha-crystallin. On the other hand, femtosecond transient absorption spectroscopy was used to check the occurrence of any type I photoactivity of oxyblepharismin bound to alpha-crystallin. The existence of a particular type of fast photoinduced reaction, not observed in former studies with human serum albumin but present in the natural oxyblepharismin-binding protein, could here be evidenced but no specific reaction was observed during the first few nanoseconds after excitation. Partial denaturation of alpha-crystallin was however found to alter the excited-state behaviour of its complex with oxyblepharismin, making it partly resemble that of free oxyblepharismin in solution.


Assuntos
Perileno/análogos & derivados , alfa-Cristalinas/metabolismo , Animais , Bovinos , Transporte de Elétrons , Olho/efeitos dos fármacos , Olho/metabolismo , Luz , Óptica e Fotônica , Perileno/metabolismo , Perileno/toxicidade , Fotoquimioterapia , Ligação Proteica , Desnaturação Proteica , Prótons , Fatores de Tempo
10.
J Diabetes Sci Technol ; 2(5): 873-81, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19885272

RESUMO

Miniaturization of clinical chemistry analyzers can empower research conducted to better understand, diagnose, manage, and cure diseases such as diabetes. For the last decade, we have been working on the design and development of miniaturized clinical chemistry devices, including a Diabetic Chip (diabetiChip). These devices measure a small array of analytes, are small, portable, fast, easy-to-operate, and inexpensive. The chosen analytical method for the diabetiChip uses bioluminescence, which is highly sensitive and specific, and is based on photon counting and specific enzymatic reactions. Bioluminescent reactions were intentionally chosen for analyzing metabolic reactions because they use some of the central nodes of metabolism, such as adenosine triphosphate. Operations of the diabetiChip's information processing ware are the focus of this paper; we show the feasibility of using a set of kinase-containing enzymatic reactions of a firefly bioluminescence-coupled glucose assay in designing the diabetiChip. We have developed and tested the feasibility of the glucose assay; the assay's analytical detection limits (before sample dilution) were 5-185 microM. Uncertainty associated with reporting a 100 microM concentration was about +/- 5 microM. The results show that an FFL bioluminescent-coupled glucose assay is promising in terms of reducing sample volume and cost. The concept of GlucoFaces in visualizing measurements of the diabetiChip is also discussed.

11.
Graefes Arch Clin Exp Ophthalmol ; 244(8): 996-1002, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16365737

RESUMO

BACKGROUND: The generation of an atraumatic posterior vitreous detachment (PVD), a common goal in vitreoretinal surgery, is a challenge, particularly in children and young trauma patients. Plasmin has been proposed as an adjunct to vitrectomy to enzymatically generate a PVD. Low doses of streptokinase-activated plasmin were tested in human pilot studies. This dose-escalation study assesses the safety range of intravitreal human streptokinase-plasmin in rabbits. METHODS: Plasminogen was isolated from human plasma by affinity chromatography, followed by activation with streptokinase (1:1), to generate the streptokinase-plasmin complex. Enzyme doses from 0.1-7 activity units (AU, in 0.1 ml) were injected into the mid-vitreous of 35 eyes; six control eyes were injected with balanced salt solution (BSS, 0.1 ml). Thirty minutes after injection, a two-port vitrectomy was performed. Fundus and slit lamp examinations were performed on days 1 and 7. On days 2 and 7, bright flash electroretinography was performed and compared with preoperative recordings. Some animals receiving higher doses of streptokinase-plasmin (1-7 AU) were followed clinically and with electroretinography for up to 9 months. RESULTS: A mild-to-moderate inflammatory response was seen in both control and plasmin-treated eyes on day 1, but had disappeared completely by day 7 in most eyes. In the 7 AU group, inflammation was stronger and more protracted. Two of three eyes from this group developed wrinkling of the medullary rays; one of them showed discoloration and traction at the medullary rays in the late follow-up. Electroretinograms (ERGs) of vitrectomized control eyes showed the following changes from preoperative values: 48 h, a-wave -11.10% [no significant (n.s.)], b-wave -14.62% (P=0.046); 7 days, a-wave +9.18% (n.s.), b wave +11.69% (n.s.). For the enzyme-treated eyes: 48 h: a-wave -20.43% (P<0.001), b-wave -9.57% (p<0.001); 7 days: a wave -14.21% (P<0.001), b-wave +2.48% (P<0.001). There was no evidence of dose-dependent ERG changes in enzyme-treated eyes at doses up to 5 AU. Groups of up to 3 AU were investigated by light and transmission electron microscopy, without evidence of toxicity. CONCLUSION: Streptokinase-plasmin doses up to 3 AU were found to be safe when injected into rabbit eyes followed by vitrectomy.


Assuntos
Plasminogênio/administração & dosagem , Estreptoquinase/administração & dosagem , Vitrectomia/métodos , Descolamento do Vítreo/cirurgia , Animais , Cromatografia de Afinidade , Terapia Combinada , Combinação de Medicamentos , Eletrorretinografia , Humanos , Injeções , Estimulação Luminosa , Plasminogênio/efeitos adversos , Plasminogênio/isolamento & purificação , Coelhos , Retina/efeitos dos fármacos , Retina/fisiologia , Estreptoquinase/efeitos adversos , Vitrectomia/efeitos adversos , Corpo Vítreo/efeitos dos fármacos
12.
Diabetes Technol Ther ; 6(1): 61-4, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15000772

RESUMO

About 100 million Americans visit science centers each year to participate in experiential science and technology activities. There is great potential for diabetes awareness and education via the several hundreds of science centers in the United States. Most science centers tend to avoid medically related topics in part because of the difficulty in meeting the interactive goals of science center activities. The Utah Science Center (USC) is addressing these difficulties by creating environments for personal interactive activities in a range of medically related topics, including diabetes. The USC will open in early 2005 in Salt Lake City. The design of diabetes activities for the USC is reviewed: (1) activities (aims, description, stages of development, and partnerships); (2) specific stage I activities (body mass index, "feeling" hypoglycemia, and urine chemistry); and (3) conclusion.


Assuntos
Diabetes Mellitus , Educação Médica/métodos , Museus , Conscientização , Humanos , Utah
13.
Environ Pollut ; 116(2): 215-23, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11806449

RESUMO

Seedlings of the salt secreting mangrove Avicennia marina were exposed to fumes of the volatile fraction of light Arabian crude oil (VFCO) under controlled conditions. Rates of salt secretion were determined in leaves fumigated for 0, 3, and 6 h under four different salinity levels (10, 20, 30, and 40 ppt). Studying the effect of these fumigation periods on stomatal resistance and transpiration was restricted to one salinity level (20 ppt). Opposite to salinity, increasing the fumigation period significantly reduced both salt secretion and transpiration with a significant increase in the stomatal resistance to gas diffusion. During the first day of recovery from fumigation stress, different stomatal oscillation patterns were observed in the treated plants. The amplitude of the oscillations increased with the duration of fumigation. as did the time required for stomatal recovery. Seedlings fumigated for 3 h started to recover within 48 h, while full recovery in seedlings fumigated for 6 h required almost twice that period. The apparent recovery process was evident in the damping off of the amplitude of stomatal oscillations during the measurements period. Data presented herein show that the exposure of mangrove seedlings to VFCO disturbs the normal functions of two major structures in the leaves, i.e. the stomata and the salt glands. The ecophysiological significance of these results was discussed in relation to previous studies.


Assuntos
Exposição Ambiental , Petróleo/efeitos adversos , Plantas , Cloreto de Sódio/farmacocinética , Folhas de Planta/fisiologia , Árvores/crescimento & desenvolvimento , Volatilização
15.
Circulation ; 102(17): 2111-7, 2000 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-11044429

RESUMO

BACKGROUND: Oxidized LDL (oxLDL) promotes atherogenesis, and antioxidants reduce lesions in experimental models. OxLDL-mediated effects on c-Myc are poorly characterized, and those on c-Myc nuclear pathways are completely unknown. c-Myc stimulates smooth muscle cell (SMC) proliferation and could be involved in atherosclerosis. We investigated the early effects of oxLDL and alpha-tocopherol on c-Myc, its binding partner Max, and the carboxy-terminal domain-binding factors activator protein-2 and elongation 2 factor in human coronary SMCs. We also investigated whether 9-week treatment of Watanabe heritable hyperlipidemic (WHHL) rabbits with diet-enriched alpha-tocopherol reduces c-Myc expression and oxLDL in the left coronary artery. METHODS AND RESULTS: OxLDL enhanced c-Myc/Max expression and transcription by cotransfection assay and the nuclear activities of E2F and activator protein-2 by binding shift and supershift in coronary SMCs. alpha-Tocopherol significantly reduced these molecular events. Furthermore, alpha-tocopherol reduced early lesions, SMC density, and the immunohistochemical presence of c-Myc, which colocalized with oxLDL/foam cells in the coronaries of WHHL rabbits. CONCLUSIONS: We provide the first evidence that oxLDL and alpha-tocopherol may influence c-Myc activation and several c-Myc-dependent signaling pathways in human coronary SMCs. The observation that in vivo, an antioxidant reduces both c-Myc and oxLDL in early coronary lesions of rabbits is consistent with, but does not prove, the hypothesis that c-Myc-dependent factors activated by oxidative processes contribute to atherogenesis and coronary heart disease.


Assuntos
Proteínas de Transporte , Proteínas de Ciclo Celular , Hiperlipidemias/metabolismo , Lipoproteínas LDL/farmacologia , Músculo Liso Vascular/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transdução de Sinais , Vitamina E/farmacologia , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Fatores de Transcrição de Zíper de Leucina Básica , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição E2F , Humanos , Hiperlipidemias/tratamento farmacológico , Fatores de Transcrição Kruppel-Like , Músculo Liso Vascular/efeitos dos fármacos , Oxirredução , Proteínas Proto-Oncogênicas c-myc/fisiologia , Coelhos , Proteína 1 de Ligação ao Retinoblastoma , Fator de Transcrição DP1 , Fatores de Transcrição/metabolismo , Vitamina E/uso terapêutico
16.
Curr Eye Res ; 21(2): 597-601, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11148595

RESUMO

PURPOSE: To determine the uptake, location and fluorescence of hypericin, the active ingredient in St. John's Wort, in situ in the isolated intact calf lens. METHODS: The absorption and fluorescence spectra of hypericin 10(-5 ) M were measured in DMSO/phosphate buffer, pH 7.4) [PBS] (1/10 in volume) in the presence of alpha-crystallin (0.5 and 1.1 mg/ml). Bovine lenses were incubated in the dark for 24 hours in 10(-4) M hypericin in a DMSO/PBS (1/10 in volume) mixture. Diffused hypericin fluorescence emission was detected with a fluorescence stereomicroscope from the PBS washed lens surface. A lens-holder specially built for front-surface excitation-detection was used to measure fluorescence emission and excitation spectra of intact lenses incubated with hypericin solutions. RESULTS: As increasing concentrations of alpha-crystallin were added, the absorption and fluorescence spectra of hypericin in DMSO/PBS (1/10 in volume) changed, indicating a binding between the chromophore and the lens protein. Fluorescence emission spectra detected from the lens surface (lambda( em) = 601 and 651 nm; lambda(exc) = 550 nm) confirmed that hypericin does bind to the ocular tissues. CONCLUSIONS: The results we obtained in simplified model systems can provide clues to investigate the effects of hypericin on lens properties in physiological conditions. Hypericin could in fact bind to lens protein thus increasing the retention time of hypericin in the eye and possibly altering a-crystallin properties as a chaperone. Should therefore hypericin be taken up by the lens, this can be detected, non-invasively by its fluorescence. Therefore, ophthalmologists may use a slit-lamp or scanning fluorometry to monitor the uptake of hypericin in the eyes of patients using St. John's Wort or receiving high doses of hypericin while undergoing photodynamic therapy.


Assuntos
Cristalino/metabolismo , Perileno/análogos & derivados , Perileno/farmacocinética , Absorção , Animais , Antracenos , Bovinos , Cristalinas/metabolismo , Fluorescência , Técnicas In Vitro , Perileno/química , Perileno/metabolismo , Solubilidade , Soluções , Distribuição Tecidual
17.
Am J Otol ; 19(4): 435-42, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9661751

RESUMO

OBJECTIVE: This study aimed to examine the effectiveness of intratympanic injection of gentamicin as a nonsurgical treatment option in the treatment of patients with unilateral Meniere's disease who are refractory to medical treatment. STUDY DESIGN: The study design was a prospective case series. SETTING: The study was conducted at a physician's office setting in a tertiary care hospital. PATIENTS: The results of 37 patients who became eligible for reporting according to the American Academy of Otolaryngology Head and Neck Surgery (AAO-HNS) guidelines for reporting treatment results of Meniere's disease were reviewed. INTERVENTION: Intratympanic injections of a prepared gentamicin concentration of approximately 30 mg/ml were given weekly until the patient reported cessation of vertigo attacks. Patients reclined for 45 minutes after each injection. MAIN OUTCOME MEASURES: The 1995 AAO-HNS guidelines were used in this report, and measures included pure-tone hearing results, word recognition scores, vertigo control scores, and ice-water calories after a minimum of 24 months of follow-up. RESULTS: Vertigo control was achieved in 32 patients (87%). Fifteen patients (41%) had complete recovery from vertigo spells, 17 patients (46%) had substantial recovery, and 5 patients (14%) had treatment failure requiring additional surgery to control vertigo. Hearing results showed that 21 patients (72%) had unchanged or better hearing, 10 patients (28%) had an average threshold shift of 10-25 dB, 4 patients (11%) had a threshold shift between 16 and 25 dB, 1 patient (3%) had a threshold shift between 26 and 40 dB, and 1 patient (3%) had a threshold shift of > 40 dB. CONCLUSIONS: The authors found intratympanic gentamicin to be a useful alternative to surgery. The flexible treatment protocol allowed for better hearing monitoring compared to the more frequent injection schedules of other studies and yielded a lower rate of severe hearing loss. It had a higher failure rate for vertigo control and a greater amount of hearing loss than the author's experience with vestibular nerve section.


Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Gentamicinas/uso terapêutico , Doença de Meniere/tratamento farmacológico , Membrana Timpânica/efeitos dos fármacos , Testes Calóricos , Feminino , Humanos , Masculino , Doença de Meniere/complicações , Pessoa de Meia-Idade , Estudos Prospectivos , Vertigem/diagnóstico , Vertigem/etiologia
18.
Laryngoscope ; 107(10): 1341-4, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9331310

RESUMO

Intact canal wall mastoidectomy techniques for cholesteatoma are often followed by a planned second look for residual disease and possible ossicular reconstruction. Endoscopic techniques may reduce morbidity but introduce new concerns. Twenty-five consecutive second-look procedures were performed from July 1994 to July 1996 utilizing endoscopes in 19 cases and avoiding or terminating their use in the others because of known difficult anatomy, inadequate exposure, or excessive bleeding. Thirteen cases were prospectively explored first through a planned exclusively endoscopic approach and then opened for a conventional second look in comparison. In one of the 13 cases, endoscopy was abandoned. There were no cases in which endoscopy yielded a false-negative result. Endoscopes underestimated the size of recurrence in one case. Our experience, indications, and precautions for endoscope-assisted second-stage tympanomastoidectomy are presented.


Assuntos
Colesteatoma da Orelha Média/cirurgia , Endoscopia/métodos , Processo Mastoide/cirurgia , Adulto , Estudos de Casos e Controles , Criança , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Reoperação , Membrana Timpânica/cirurgia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA