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1.
Musculoskelet Surg ; 104(3): 295-301, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31414366

RESUMO

PURPOSE: Open reduction and internal fixation with a locking plate are performed frequently to treat fractures of the proximal humerus. Avascular necrosis and non-union or malunion are potential complications of this procedure, which lead to specific fracture sequelae. The aim of this study was to investigate the clinical and radiological results of patients treated by removal of a failed locking plate of the proximal humerus and simultaneous implantation of a reverse total shoulder prosthesis. METHODS: Twenty-one patients (f = 17, m = 4; mean age 70 years) out of 29 patients were available for follow-up after a mean period of 45 (30-65) months. At follow-up, all patients were assessed with the constant score and the ASES score as well as plain radiographs. RESULTS: In comparison with the preoperative values, abduction (31° vs. 115°; p < 0.001) and forward flexion (34° vs. 121°; p < 0.001) improved until follow-up, while the pain score on a visual analog scale decreased (6.7 vs. 0.9; p < 0.001). At follow-up, the mean ASES score rated 73 and the constant score rated 62. The radiologic findings included scapular notching (n = 7; 33%), radiolucency (n = 4; 19%), heterotopic ossifications (n = 3; 14%), and stress shielding (n = 4; 19%). CONCLUSION: Reverse total shoulder arthroplasty is a useful instrument for the treatment of failed locking plate osteosynthesis of the proximal humerus in elderly patients. The patients benefit from both pain relief and improved shoulder function. The rate of radiologic changes like scapular notching, radiolucency, stress-shielding and heterotopic ossifications at follow-up is notable.


Assuntos
Artroplastia do Ombro/métodos , Placas Ósseas , Remoção de Dispositivo , Fraturas do Ombro/cirurgia , Idoso , Feminino , Seguimentos , Fixação Interna de Fraturas/instrumentação , Humanos , Masculino , Ossificação Heterotópica/diagnóstico por imagem , Amplitude de Movimento Articular , Reoperação , Estudos Retrospectivos , Fraturas do Ombro/complicações , Fraturas do Ombro/diagnóstico por imagem
2.
Orthopade ; 38(1): 36-40, 2009 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-19093098

RESUMO

The treatment of traumatic anterior glenohumeral instability has been a topic of debate over the last couple of decades. However, a consensus exists regarding the necessity of an individualized treatment plan based on the type and degree of instability and the patient's functional demands. Various open and arthroscopic techniques are among the currently used surgical procedures. Open reconstruction of the capsulolabral complex had been considered the treatment of choice for many years, but the latest results for arthroscopic anterior shoulder stabilization demonstrate its increasing use. The current literature suggests that with the introduction of suture anchors, it is possible to mirror the principles of open anterior shoulder stabilization and thus combine the general advantages of arthroscopic surgery with a low recurrence rate.


Assuntos
Artroplastia/métodos , Artroscopia/métodos , Instabilidade Articular/patologia , Instabilidade Articular/cirurgia , Luxação do Ombro/patologia , Luxação do Ombro/cirurgia , Articulação do Ombro/cirurgia , Alemanha , Humanos , Articulação do Ombro/patologia , Técnicas de Sutura
3.
Bone Joint J ; 100-B(6): 761-766, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29855243

RESUMO

Aims: The reasons for failure of a hemirthroplasty (HA) when used to treat a proximal humeral fracture include displaced or necrotic tuberosities, insufficient metaphyseal bone-stock, and rotator cuff tears. Reverse total shoulder arthroplasty (rTSA) is often the only remaining form of treatment in these patients. The aim of this study was to evaluate the clinical outcome after conversions from a failed HA to rTSA. Material and Methods: A total of 35 patients, in whom a HA, as treatment for a fracture of the proximal humerus, had failed, underwent conversion to a rTSA. A total of 28 were available for follow-up at a mean of 61 months (37 to 91), having been initially reviewed at a mean of 20 months (12 to 36) postoperatively. Having a convertible design, the humeral stem could be preserved in nine patients. The stem was removed in the other 19 patients and a conventional rTSA was implanted. At final follow-up, patients were assessed using the American Shoulder and Elbow Surgeons (ASES) score, the Constant Score, and plain radiographs. Results: At final follow-up, the mean ASES was 59 (25 to 97) and the mean adjusted Constant Score was 63% (23% to 109%). Both improved significantly (p < 0.001). The mean forward flexion was 104° (50° to 155°) and mean abduction was 98° (60° to 140°). Nine patients (32%) had a complication; two had an infection and instability, respectively; three had a scapular fracture; and one patient each had delayed wound healing and symptomatic loosening. If implants could be converted to a rTSA without removal of the stem, the operating time was shorter (82 minutes versus 102 minutes; p = 0.018). Conclusion: After failure of a HA in the treatment of a proximal humeral fracture, conversion to a rTSA may achieve pain relief and improved shoulder function. The complication rate is considerable. Cite this article: Bone Joint J 2018;100-B:761-6.


Assuntos
Artroplastia do Ombro/métodos , Hemiartroplastia/efeitos adversos , Reoperação/métodos , Fraturas do Ombro/cirurgia , Prótese de Ombro/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Ombro/efeitos adversos , Feminino , Seguimentos , Hemiartroplastia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Amplitude de Movimento Articular , Reoperação/efeitos adversos , Articulação do Ombro/cirurgia , Falha de Tratamento , Resultado do Tratamento
4.
Musculoskelet Surg ; 101(2): 173-180, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28205145

RESUMO

Is reverse total shoulder arthroplasty a feasible treatment option for failed shoulder arthroplasty? A retrospective study of 44 cases with special regards to stemless and stemmed primary implants. BACKGROUND: Due to humeral or glenoid bone-loss and rotator cuff insufficiency reverse total shoulder arthroplasty often means the only remaining treatment option in revision shoulder arthroplasty. This study investigates the clinical outcome of patients treated with a reverse total shoulder in revision cases with special regard to stemless and stemmed primary implants. MATERIALS AND METHODS: From 2010 to 2012 60 failed shoulder arthroplasties were converted to reverse total shoulder arthroplasty. Forty-four patients were available for follow-up after a mean of 24 months. Patients were assessed with X-rays, Constant- and ASES Score and a questionnaire about their subjective satisfaction. RESULTS: The total number of observed complications was seven (16%). Ninety-eight percent of the patients were satisfied with their clinical result. Patients achieved a mean normalized constant score of 70.2% and a mean ASES Score of 65.3. Patients with stemless primary implants achieved a higher normalized constant score than patients with stemmed primary implants (82 vs. 61.8%; p = 0009). CONCLUSION: Reverse total shoulder arthroplasty provides satisfactory clinical results and a high patient satisfaction in revision shoulder arthroplasty. The complication rate needs to be considered and discussed with the patient prior to surgery. Presence or absence of a stem of revised shoulder arthroplasties interferes with the outcome. LEVEL OF EVIDENCE IV: (Retrospective study).


Assuntos
Artroplastia do Ombro/métodos , Prótese de Ombro , Idoso , Idoso de 80 Anos ou mais , Artroplastia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Desenho de Prótese , Estudos Retrospectivos , Falha de Tratamento
5.
Sportverletz Sportschaden ; 20(1): 36-42, 2006 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-16544215

RESUMO

The idiopathic scoliosis is a three dimensional spinal deformity mostly occurring in female adolescents. Untreated it can progress and result in back pain, impaired lung capacity and psychosocial disorders due to the cosmetic appearance of the deformed trunk. The treatment depends on the severity of the curve and ranges from physiotherapy and observation, brace treatment to surgical treatment with partial correction and fusion of the primary curve. Patients with an idiopathic scoliosis should be encouraged to actively take part in sports activities. Positive influences on the general fitness including the lung function, on the trunk muscles and on the psyche can be expected. There are no scientific data indicating that any kind of sport activities alter the natural history of idiopathic scoliosis.


Assuntos
Terapia por Exercício/métodos , Imobilização/métodos , Laminectomia/métodos , Escoliose/terapia , Esportes , Adolescente , Feminino , Humanos , Guias de Prática Clínica como Assunto , Padrões de Prática Médica
6.
Arch Ophthalmol ; 109(1): 77-83, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1987954

RESUMO

Standardized perimetry and nerve fiber layer and color fundus photography were performed annually on 1344 eyes with elevated intraocular pressures. In 83 eyes, glaucomatous field defects developed that met rigid criteria on manual kinetic and suprathreshold static perimetry. Individual nerve fiber layer photographs were read by two masked observers. The more sensitive of the two identified nerve fiber layer defects in 88% of readable photographs at the time field loss first occurred; 60% (6/10) of eyes already had nerve fiber layer defects 6 years before field loss. In contrast, the nerve fiber layer was considered abnormal in only 11% (3/27) of normal eyes and 26% (84/327) of hypertensive eyes. The location of nerve fiber layer and field defects closely corresponded, but nerve fiber layer loss was generally more widespread. Examiner experience and severity of optic nerve damage influenced results. Mild focal defects were more readily recognized than more severe diffuse atrophy. Nerve fiber layer defects expanded with time, often by the development and coalescence of adjacent areas of damage.


Assuntos
Glaucoma/patologia , Atrofia Óptica/patologia , Campos Visuais , Adulto , Idoso , Feminino , Seguimentos , Fundo de Olho , Glaucoma/fisiopatologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Fotografação , Estudos Prospectivos , Testes de Campo Visual
7.
Peptides ; 22(12): 2329-43, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11786210

RESUMO

Peptides have the potential to be potent pharmaceutical agents for the treatment of many central nervous system derived maladies. Unfortunately peptides are generally water-soluble compounds that will not enter the central nervous system, via passive diffusion, due to the existence of the blood-brain barrier. Peptides can also undergo metabolic deactivation by peptidases, thus further reducing their therapeutic benefits. In targeting peptides to the central nervous system consideration must be focused both on increasing bioavailability and enhancing brain uptake. To date multiple strategies have been examined with this focus. However, each strategy comes with its own complications and considerations. In this review we assess the strengths and weaknesses of many of the methods currently being examined to enhance peptide entry into the central nervous system.


Assuntos
Barreira Hematoencefálica , Peptídeos/química , Peptídeos/farmacocinética , Disponibilidade Biológica
8.
J Med Microbiol ; 8(2): 325-35, 1975 May.
Artigo em Inglês | MEDLINE | ID: mdl-806688

RESUMO

Perforated plastic chambers implanted subcutaneously in guinea-pigs and rabbits became encapsulated and filled with sterile transudate. When these chambers in guinea-pigs were inoculated with various strans of Neisseria gonorrhoeae, persistent infections were achieved without the use of anti-inflammation agents and in the presence of a substantial predominantly polymorphonuclear inflammatory response. Two strains with small colonies similar to types 1 and 2, and one strain with large colonies similar to type 4 of Kellogg et al. (1963 and 1968), showed differences in infectivity comparable with those that might be expected in man, and passage through guinea-pig chambers increased this infectivity. Rabbit chambers could not be infected without the use of an anti-inflammation drug (betamethasone), and differences in infectivity between strains were not as clear cut. The growth of N. gonorrhoeae in chambers in the guinea-pig provides a convenient model system for studying some aspects of the pathogenicity of this organism.


Assuntos
Técnicas Bacteriológicas , Exsudatos e Transudatos/microbiologia , Inflamação , Neisseria gonorrhoeae/patogenicidade , Animais , Betametasona/farmacologia , Eritrócitos/citologia , Exsudatos e Transudatos/citologia , Gonorreia/microbiologia , Cobaias , Leucócitos/citologia , Linfócitos/citologia , Modelos Biológicos , Neisseria gonorrhoeae/crescimento & desenvolvimento , Plásticos , Coelhos , Especificidade da Espécie
9.
Orthopade ; 36(11): 1027-36, 2007 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-17962920

RESUMO

Shoulder arthroplasty is becoming increasingly important in orthopaedic surgery. Continuous development of the implants means that the modern endoprostheses make it possible to recreate the original anatomy with a high degree of accuracy. This is of decisive importance in the long-term restoration of physiological patterns of movement and achievement of pain relief. The modern shoulder arthroplasties allow adjustment of the important parameters: ante-/retroversion, inclination and offset to fit the individual anatomy of the proximal humerus. Fixation is the most important factor for the glenoid component; reduced bone stock can make this difficult. Cemented components are still the gold standard. For young patients surface replacement arthroplasty can be a good alternative treatment for early stages of osteoarthritis. In cuff tear arthropathy reverse prostheses can be used. Reversing the anatomical relationship between glenoid and humerus leads to medialisation and lowering of the center of rotation, which in turn leads to increased tension on the deltoid muscle. Because of the high complication rate this operation should be performed only by experienced shoulder surgeons.


Assuntos
Análise de Falha de Equipamento , Prótese Articular , Desenho de Prótese , Articulação do Ombro/cirurgia , Fenômenos Biomecânicos , Humanos , Ajuste de Prótese , Amplitude de Movimento Articular/fisiologia , Articulação do Ombro/fisiopatologia
10.
Z Orthop Ihre Grenzgeb ; 140(4): 385-9, 2002.
Artigo em Alemão | MEDLINE | ID: mdl-12183786

RESUMO

PURPOSE: Aim of this study was to compare the results of the surgical repair of full-thickness rotator cuff tears with and without resection of the lateral clavicle. METHODS: 102 patients were retrospectively observed by an independent observer for a mean follow-up of 21 months (12 - 42). 93 patients had medium to large sized tears (1 - 5 cm) and 9 had massive tears (> 5 cm). Additional resection of the lateral end of the clavicle was performed in 20 patients. The mean age of the 68 men and 34 woman was 57.3 years (28 - 80). For the evaluation the Constant score, the ASES score and the visual analogue scales for postoperative satisfaction, function, strength, pain and ADL were used. RESULTS: The subjective results were good to excellent in 79 patients (76 %), fair in 14 patients (13.7 %) and poor in 9 patients (8.9 %), too. After surgery the Constant score was 87 % of the contralateral side for all patients, 89 % for group I and 84 % for group II and the mean ASES score was 86 %, 87 % and 82 % of the contralateral side. Comparing the pre- and post-operative values on the visual analogue scale pain and disability in ADL were decreased highly significantly in all patients (p < 0.001). CLINICAL RELEVANCE: We conclude that in patients with a full-thickness rotator cuff tear the patient's satisfaction and function will improve after acromioplasty and rotator cuff repair. The results are not significantly influenced by an additional resection of the lateral clavicle.


Assuntos
Clavícula/cirurgia , Lesões do Manguito Rotador , Técnicas de Sutura , Atividades Cotidianas/classificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Satisfação do Paciente , Complicações Pós-Operatórias/etiologia , Manguito Rotador/cirurgia
11.
J Pharmacol Exp Ther ; 295(3): 972-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11082431

RESUMO

Insulin crosses the blood-brain barrier (BBB) via receptor-mediated transcytosis and has been suggested to augment uptake of peripheral substances across the BBB. The delta-opioid receptor-selective peptide D-penicillamine(2,5) (DPDPE), a Met-enkephalin analog, produces analgesia via a central nervous system-derived effect. In vitro (K(cell), microl. min(-1). mg(-1)) and in situ (K(in), microl. min(-1). g(-1)) analyses of DPDPE transport (K(cell) = 0.56 +/- 0. 15; K(in) = 0.28 +/- 0.03) revealed significant (P <.01) increases in DPDPE uptake by the BBB with 10 microM insulin (K(cell) = 1.61 +/- 0.25; K(in) = 0.48 +/- 0.04). In vitro cellular uptake was significantly increased (P <.05) at 1 microM insulin, whereas no significant uptake was observed with CTAP (a somatostatin opioid peptide analog) or sucrose (a paracellular diffusionary marker). No significant change in uptake was seen with DPDPE, CTAP, or sucrose in the presence of holo-transferrin (0-100 microM), indicating that the effect of insulin on DPDPE was not a generalized effect of receptor endocytosis. Insulin did not affect P-glycoprotein efflux, a mechanism that has shown affinity for DPDPE. A similar uptake of DPDPE into the brain (64% increase) was seen with the in situ brain perfusion model. Analgesic assessment revealed a significant decline in DPDPE (i.v.)-induced analgesia with increasing concentrations of insulin (i.v., i.c.v., s.c.) in a dose-dependent manner. Thus, insulin significantly increases DPDPE uptake across the BBB by a specific mechanism. The analgesic effect seen with DPDPE and insulin coadministration was shown to decrease, indicating that insulin reduces the analgesic effect within the central nervous system rather than at the BBB.


Assuntos
Analgésicos Opioides/farmacocinética , Barreira Hematoencefálica/efeitos dos fármacos , Insulina/farmacologia , Analgésicos Opioides/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Encéfalo/metabolismo , Bovinos , Células Cultivadas , Relação Dose-Resposta a Droga , Endotélio Vascular/metabolismo , D-Penicilina (2,5)-Encefalina/farmacocinética
12.
Am J Physiol Heart Circ Physiol ; 280(3): H1241-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11179069

RESUMO

Effects of inflammatory pain states on functional and molecular properties of the rat blood-brain barrier (BBB) were investigated. Inflammation was produced by subcutaneous injection of formalin, lambda-carrageenan, or complete Freund's adjuvant (CFA) into the right hind paw. In situ perfusion and Western blot analyses were performed to assess BBB integrity after inflammatory insult. In situ brain perfusion determined that peripheral inflammation significantly increased the uptake of sucrose into the cerebral hemispheres. Capillary depletion and cerebral blood flow analyses indicated the perturbations were due to increased paracellular permeability rather than vascular volume changes. Western blot analyses showed altered tight junctional protein expression during peripheral inflammation. Occludin significantly decreased in the lambda-carrageenan- and CFA-treated groups. Zonula occluden-1 expression was significantly increased in all pain models. Claudin-1 protein expression was present at the BBB and remained unchanged during inflammation. Actin expression was significantly increased in the lambda-carrageenan- and CFA-treated groups. We have shown that inflammatory-mediated pain alters both the functional and molecular properties of the BBB. Inflammatory-induced changes may significantly alter delivery of therapeutic agents to the brain, thus affecting dosing regimens during chronic pain.


Assuntos
Barreira Hematoencefálica/fisiologia , Proteínas de Membrana/biossíntese , Inflamação Neurogênica/fisiopatologia , Junções Íntimas/metabolismo , Actinas/análise , Actinas/biossíntese , Animais , Western Blotting , Capilares/fisiologia , Radioisótopos de Carbono , Carragenina , Circulação Cerebrovascular/fisiologia , Claudina-1 , Desinfetantes , Feminino , Formaldeído , Adjuvante de Freund , Proteínas de Membrana/análise , Inflamação Neurogênica/induzido quimicamente , Ocludina , Ratos , Ratos Sprague-Dawley , Sacarose/farmacocinética , Junções Íntimas/química
13.
Int J Sport Nutr ; 3(3): 272-89, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8220393

RESUMO

To determine relationships among dietary carbohydrate, aerobic exercise training, the thermic effect of food (TEF), and hormonal responses to feeding, 8 trained and 7 sedentary men consumed diets providing 15, 45, or 75% of energy as carbohydrate for 5 days. On Day 6, metabolic rate was measured before as well as 30, 60, 90, and 120 min after an 868-kcal liquid test breakfast. Blood was sampled hourly during Day 5 and during each metabolic rate measurement. The trained group had a larger TEF (40 +/- 2.4 vs. 31 +/- 3.0 kcal/2 hrs), greater insulin sensitivity, and greater plasma prolactin and cortisol levels. As carbohydrate in the treatment diet increased, carbohydrate utilization and thyroid stimulating hormone were higher and thyroxine was lower, but TEF was not significantly different. After the test meal, trained individuals had a higher TEF but the carbohydrate content of the treatment diet did not influence TEF.


Assuntos
Temperatura Corporal/fisiologia , Carboidratos da Dieta/farmacologia , Exercício Físico/fisiologia , Hormônios/metabolismo , Adolescente , Adulto , Ritmo Circadiano , Metabolismo Energético/fisiologia , Humanos , Masculino
14.
Br J Anaesth ; 74(6): 638-42, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7640115

RESUMO

A photographic version of the Mallampati test was developed and applied to 242 pregnant patients at 12 weeks' gestation and again at 38 weeks' gestation. At 38 weeks the number of grade 4 cases had increased by 34% (P < 0.001). This is in agreement with other evidence which suggests that difficult laryngoscopy is slightly more frequent in obstetrics (1.7%) than in general surgery (1.3%). The increase in Mallampati score correlated with gain in body weight (r = 0.3, P < 0.001), which gives some support to the concept that fluid retention is the underlying cause. We conclude that pharyngeal oedema causes some hindrance to tracheal intubation in obstetrics, but not enough to explain the high failure rate reported. A case is made for rationalizing the management of difficult intubation. Our data also show that more research is needed on factors which affect Mallampati's test, particularly neck extension.


Assuntos
Intubação Intratraqueal , Edema Laríngeo/complicações , Faringe/patologia , Gravidez/fisiologia , Antropometria , Peso Corporal , Feminino , Humanos , Laringoscopia , Reprodutibilidade dos Testes , Fatores de Tempo
15.
J Neurochem ; 75(1): 424-35, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10854288

RESUMO

[D-Pen(2),D-Pen(5)]-Enkephalin (DPDPE) is an enzymatically stable delta-opioid receptor-selective peptide, which was modified by the trimethylation of the Phe(4) residue to give beta-methyl-2', 6'-dimethylphenylalanine (TMP), resulting in four conformations : (2R,3S)-beta-Phe-DPDPE, (2R,3R)-beta-Phe-DPDPE, (2R, 3S)-beta-Phe-DPDPE, and (2S,3R)-beta-Phe-DPDPE. Synthesis was by solid-phase techniques using enantiomerically pure amino acids to give the four optically pure diastereoisomer peptides. The potency and selectivity (delta- versus mu-opioid receptor) were evaluated by radioreceptor binding in rat brain, with a mu/delta ratio decrease for all TMP conformations, compared with the parent compound (DPDPE). Octanol/buffer distribution analysis showed enhanced lipophilicity of all TMP forms, with a sixfold enhancement associated with (2S,3S)-TMP. In situ vascular perfusion in anesthetized rats showed a 1.6-fold (p < 0.01) increase in the ratio of brain uptake for (2S,3S)-TMP and a 1.5-fold (p < 0.01) decrease in uptake for (2R,3R)-TMP. Saturability of (2S,3S)-TMP was shown (p < 0.01) against 100 microM unlabeled DPDPE, showing a shared nondiffusionary transport system. P-glycoprotein affinity was shown in situ for the parent and (2S,3S)-TMP (p < 0.01). Protein binding capacity of the TMP compounds in rat plasma and in situ mammalian bovine serum albumin-Ringer showed (2R,3S)-TMP and (2S,3R)-TMP with the lowest degree of protein binding (p < 0.01), and (2S,3S)-TMP and (2R,3R)-TMP with comparable affinities to DPDPE. Analgesia, via intravenous administration, showed significantly reduced (p < 0.01) end effect and time course for (2R,3R)-TMP, (2R,3S)-TMP, and (2S, 3R)-TMP as compared with DPDPE. These results demonstrate that topographical modification in a conformationally restricted peptide can significantly modulate potency and receptor selectivity, binding capacity, enzymatic stability, lipophilicity, P-glycoprotein affinity, and blood-brain barrier permeability, resulting in a change of bioavailability, and thereby provides insight for future peptide drug design.


Assuntos
Alanina/análogos & derivados , D-Penicilina (2,5)-Encefalina/análogos & derivados , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Alanina/química , Alanina/metabolismo , Analgesia , Animais , Barreira Hematoencefálica , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Capilares/metabolismo , Bovinos , Endotélio Vascular/metabolismo , D-Penicilina (2,5)-Encefalina/química , Feminino , Metilação , Conformação Molecular , Ratos , Ratos Sprague-Dawley , Estereoisomerismo , Relação Estrutura-Atividade
16.
J Pharmacol Exp Ther ; 298(2): 848-56, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11454951

RESUMO

Poly(ethylene glycol), or PEG, conjugation to proteins and peptides is a growing technology used to enhance efficacy of therapeutics. This investigation assesses pharmacodynamic and pharmacokinetic characteristics of PEG-conjugated [D-Pen2,D-Pen5]-enkephalin (DPDPE), a met-enkephalin analog, in rodent (in vivo, in situ) and bovine (in vitro) systems. PEG-DPDPE showed increased analgesia (i.v.) compared with nonconjugated form (p < 0.01), despite a 172-fold lower binding affinity for the delta-opioid receptor. [125I]PEG-DPDPE had a 36-fold greater hydrophilicity (p < 0.01) and 12% increase in the unbound plasma protein fraction (p < 0.01), compared with [(125)I]DPDPE. [125I]PEG-DPDPE had a 2.5-fold increase in elimination half-life (p < 0.01), 2.7-fold decrease in volume of distribution (p < 0.01), and a 7-fold decrease in plasma clearance rate (p < 0.01) to [125I]DPDPE. Time course distribution showed significant concentration differences (p < 0.01) in plasma, whole blood, liver, gallbladder, gastrointestinal (GI) content, GI tract, kidneys, spleen, urine, and brain (brain, p < 0.05), between the conjugated and nonconjugated forms. Increased brain uptake of [(125)I]PEG-DPDPE corresponded to analgesia data. [125I]PEG-DPDPE in brain was shown to be 58.9% intact, with 41.1% existing as [125I]DPDPE (metabolite), whereas [125I]DPDPE was 25.7% intact in the brain (at 30 min). In vitro P-glycoprotein affinity was shown for [125I]DPDPE (p < 0.01) but not shown for [125I]PEG-DPDPE. In vitro saturable uptake, with 100 microM DPDPE, was shown for [125I]PEG-DPDPE (p < 0.05). In this study, PEG-conjugated DPDPE seems to act as a prodrug, enhancing peripheral pharmacokinetics, while undergoing hydrolysis in the brain and allowing nonconjugated DPDPE to act at the receptor.


Assuntos
Analgésicos Opioides/farmacologia , D-Penicilina (2,5)-Encefalina/farmacologia , Polietilenoglicóis/química , Analgésicos Opioides/química , Animais , Ligação Competitiva/efeitos dos fármacos , Encéfalo/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Bovinos , Fenômenos Químicos , Físico-Química , D-Penicilina (2,5)-Encefalina/química , Feminino , Técnicas In Vitro , Injeções Intraventriculares , Iodo/química , Camundongos , Camundongos Endogâmicos ICR , Medição da Dor/efeitos dos fármacos , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
17.
N Engl J Med ; 325(20): 1412-7, 1991 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-1922252

RESUMO

BACKGROUND: Bilateral blindness unrelated to simple refractive error is twice as prevalent among blacks as among whites, although the difference narrows among the elderly. The reasons for this race- and age-related pattern are uncertain. METHODS AND RESULTS: A randomly selected, stratified, multistage cluster sample of 2395 blacks and 2913 whites 40 years of age and older in East Baltimore underwent detailed ophthalmic examinations by a single team. We identified 64 subjects who were blind in both eyes. The leading causes of blindness were unoperated senile cataract (accounting for blindness in 27 of the total of 128 eyes), primary open-angle glaucoma (17 eyes), and age-related macular degeneration (16 eyes). Together, these three disorders accounted for 47 percent of all blindness in this sample. Unoperated cataract accounted for 27 percent of all blindness among blacks, among whom it was four times more common than among whites; whites were almost 50 percent more likely than blacks to have undergone cataract extraction before the age of 80 (P less than 0.002). Primary open-angle glaucoma accounted for 19 percent of all blindness among blacks; it was six times as frequent among blacks as among whites and began 10 years earlier, on average. By contrast, age-related macular degeneration resulting in blindness was limited to whites, among whom it was the leading cause of blindness (prevalence, 2.7 per 1000; 95 percent confidence interval, 1.2 to 5.4); it affected 3 percent of all white subjects 80 years of age or older. CONCLUSIONS: The pattern of blindness in urban Baltimore appears to be different among blacks and whites. Whites are far more likely to have age-related macular degeneration, and blacks to have primary open-angle glaucoma. The high rate of unoperated cataracts among younger blacks and among elderly subjects of both races suggests that health services are underused. Half of all blindness in this urban population is probably preventable or reversible.


Assuntos
Cegueira/etnologia , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Baltimore , Cegueira/etiologia , Catarata/complicações , Análise por Conglomerados , Etnicidade , Glaucoma de Ângulo Aberto/complicações , Serviços de Saúde/estatística & dados numéricos , Humanos , Degeneração Macular/complicações , Pessoa de Meia-Idade , Prevalência , Grupos Raciais , População Urbana , População Branca/estatística & dados numéricos
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