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1.
Knee Surg Sports Traumatol Arthrosc ; 32(2): 303-310, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38318999

RESUMO

PURPOSE: This study aimed to formulate evidence-based recommendations for optimising wound management in hip and knee arthroplasty by exploring alternative methods such as barbed sutures and skin adhesives. METHODS: A Delphi panel, comprising seven orthopaedic surgeons, one musculoskeletal infectious disease specialist, and one health economics expert, was convened to evaluate the use of barbed sutures and skin adhesives for wound closure in hip and knee arthroplasty. Two systematic reviews informed the development of questionnaires, with panelists ranking their agreement on statements using a 5-point Likert scale. Consensus was achieved if ≥75% agreement. Unresolved statements were revisited in a second round. RESULTS: Consensus was reached on 11 statements, providing evidence-based recommendations. The expert panel advocates for a multilayer watertight technique using barbed sutures to prevent surgical site infections (SSI), reduce complications, shorten surgical times, optimise resources and improve cosmetic appearance. For skin closure, the panel recommends topical adhesives to decrease wound dehiscence, enhance cosmetic appearance, promote patient compliance, prevent SSIs, and optimise resources. CONCLUSION: The Delphi consensus by Italian total joint arthroplasty experts underscores the pivotal role of barbed sutures and skin adhesives in optimising outcomes. While guiding clinical decision-making, these recommendations are not prescriptive and should be adapted to local practices. The study encourages further research to enhance current evidence. LEVEL OF EVIDENCE: Level III.


Assuntos
Artroplastia do Joelho , Humanos , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/métodos , Adesivos , Técnicas de Sutura , Infecção da Ferida Cirúrgica/prevenção & controle , Suturas , Resultado do Tratamento
2.
Materials (Basel) ; 16(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37570009

RESUMO

Periprosthetic joint infections (PJIs) in arthroplasty and osteosynthesis-associated infections (OAIs) in reconstructive surgery still represent a challenging complication in orthopaedics and traumatology causing a burden worsening the patient's quality of life, for caregiver and treating physicians, and for healthcare systems. PJIs and OAIs are the result of bacterial adhesion over an implant surface with subsequent biofilm formation. Therefore, the clinical pathological outcome is a difficult-to-eradicate persistent infection. Strategies to treat PJIs and OAIs involve debridement, the replacement of internal fixators or articular prostheses, and intravenous antibiotics. However, long treatments and surgical revision cause discomfort for patients; hence, the prevention of PJIs and OAIs represents a higher priority than treatment. Local antibiotic treatments through coating-release systems are becoming a smart approach to prevent this complication. Hydrophilic coatings, loaded with antibiotics, simultaneously provide a barrier effect against bacterial adhesion and allow for the local delivery of an antibiotic. The intraoperative use of a hyaluronan (HY)-derivative coating in the form of a gel, loaded with antibiotics to prevent PJI, has recently raised interest in orthopaedics. Current evidence supports the use of this coating in the prophylaxis of PJI and IRIs in terms of clinical outcomes and infection reduction. Thus, the purpose of this narrative review is to assess the use of a commercially available HY derivative in the form of a gel, highlighting the characteristics of this biomaterial, which makes it attractive for the management of PJIs and IRIs in orthopaedics and traumatology.

3.
Antioxidants (Basel) ; 11(6)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35739958

RESUMO

Bone is a very dynamic tissue, subject to continuous renewal to maintain homeostasis through bone remodeling, a process promoted by two cell types: osteoblasts, of mesenchymal derivation, are responsible for the deposition of new material, and osteoclasts, which are hematopoietic cells, responsible for bone resorption. Osteomyelitis (OM) is an invasive infectious process, with several etiological agents, the most common being Staphylococcus aureus, affecting bone or bone marrow, and severely impairing bone homeostasis, resulting in osteolysis. One of the characteristic features of OM is a strong state of oxidative stress (OS) with severe consequences on the delicate balance between osteoblastogenesis and osteoclastogenesis. Here we describe this, analyzing the effects of OS in bone remodeling and discussing the need for new, easy-to-measure and widely available OS biomarkers that will provide valid support in the management of the disease.

4.
BMC Surg ; 22(1): 68, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35216567

RESUMO

BACKGROUND: Periprosthetic hip infections with severe proximal femoral bone loss may require the use of limb salvage techniques, but no agreement exists in literature regarding the most effective treatment. Aim of this study is to analyze the infection eradication rate and implant survival at medium-term follow-up in patients treated with megaprostheses for periprosthetic hip infections with severe bone loss. METHODS: Twenty-one consecutive patients were retrospectively reviewed at a mean 64-month follow-up (24-120). Functional and pain scores, microbiological, radiological and intraoperative findings were registered. Kaplan Meier survival analysis and log rank test were used for infection free survival and implant survival analyses. RESULTS: The infection eradication rate was 90.5%, with an infection free survival of 95.2% at 2 years (95%CI 70.7-99.3) and 89.6%(95%CI 64.3-97.3) at 5 years. Only two patients required major implant revisions for aseptic implant loosening. The most frequent complication was dislocation (38.1%). The major revision-free survival of implants was 95.2% (95%CI 70.7-99.3) at 2 years and 89.6% (95%CI 64.3-97.3) at 5 years. The overall implant survival was 83.35% (CI95% 50.7-93.94) at 2 and 5 years. Subgroup analyses (cemented versus cementless MPs, coated versus uncoated MPs) revealed no significant differences at log rank test, but its reliability was limited by the small number of patients included. CONCLUSIONS: Proximal femoral arthroplasty is useful to treat periprosthetic hip infections with severe bone loss, providing good functional results with high infection eradication rates and rare major revisions at medium-term follow-up. No conclusions can be drawn on the role of cement and coatings.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/métodos , Seguimentos , Prótese de Quadril/efeitos adversos , Humanos , Desenho de Prótese , Falha de Prótese , Reoperação/efeitos adversos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Resultado do Tratamento
5.
Int J Artif Organs ; 45(1): 113-117, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33594902

RESUMO

PURPOSE: We conducted a retrospective study to evaluate the outcomes of one-stage revision total hip arthroplasty (THA) following periprosthetic joint infection (PJI) in terms of eradication of the infection, improvement of pain and joint function. We hypothesized that this treatment strategy could lead to satisfying results in selected patients after preoperative microorganism isolation. METHODS: Ten patients underwent cementless one-stage revision hip arthroplasty with antibacterial hydrogel coating for the treatment of an infected THA. Inclusion criteria were: the presence of a known organism with known sensitivity, patients non-immunocompromised with healthy soft tissues with minimal or moderate bone loss. Mean age at surgery was 69.4 years. Assessment included objective examination, Harris hip score, visual analog scale pain score, standard X-rays. RESULTS: At a mean follow-up of 3.1 years (range, 2-5 years), none of the patients had clinical or radiographic signs suggesting recurrent infection. Follow-up examination showed significant improvement of all variables compared to pre-operative values (p < 0.05). Radiographs did not show progressive radiolucent lines or change in the position of the implant. CONCLUSIONS: One-stage revision THA with antibacterial hydrogel coated implants represents a safe and effective procedure providing infection eradication and satisfying subjective functional outcomes in selected patients.


Assuntos
Antibacterianos , Artroplastia de Quadril , Prótese de Quadril , Infecções Relacionadas à Prótese/prevenção & controle , Antibacterianos/uso terapêutico , Artroplastia de Quadril/efeitos adversos , Seguimentos , Prótese de Quadril/efeitos adversos , Humanos , Hidrogéis/uso terapêutico , Infecções Relacionadas à Prótese/diagnóstico por imagem , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
6.
Foot Ankle Surg ; 28(6): 697-708, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34688527

RESUMO

BACKGROUND: Ankle periprosthetic joint infections are rising in number, but an evidence-based gold standard treatment has not been defined yet. METHODS: We made a systematic review about the operative treatment of infections following total ankle arthroplasty. Proportional meta-analysis was used to summarize effects of the surgical techniques included. Primary outcome of this study was infection eradication, followed by complications, re-interventions, amputation rates and functions. RESULTS: We included six studies(113 patients) reporting 6 types of surgical interventions, mostly irrigation and debridement (35.4%) and two-stage revisions (24.8%). No differences among all analyzed techniques were found in the infection eradication outcome as well as in the secondary outcomes. Patients receiving a permanent spacer are most likely to end up with amputation. CONCLUSIONS: Literature dealing with infections after total ankle replacement is currently composed by few low-quality articles. The overlapping of confidence intervals related to all analyzed interventions showed no superiority of either technique. LEVEL OF EVIDENCE: III.


Assuntos
Artrite Infecciosa , Artroplastia de Substituição do Tornozelo , Infecções Relacionadas à Prótese , Antibacterianos/uso terapêutico , Artrite Infecciosa/etiologia , Artroplastia de Substituição do Tornozelo/efeitos adversos , Desbridamento/métodos , Humanos , Infecções Relacionadas à Prótese/etiologia , Infecções Relacionadas à Prótese/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
7.
J Arthroplasty ; 37(3): 565-573, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34822929

RESUMO

BACKGROUND: We evaluated the reliability of intraoperative assessment of leukocyte esterase (LE) in synovial fluid samples from patients undergoing reimplantation following implant removal and spacer insertion for periprosthetic joint infection (PJI). Our hypothesis was that a positive intraoperative LE test would be a better predictor of persistent infection than either serum C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) or the combination of serum CRP and ESR. METHODS: The records of 76 patients who received a 2-stage exchange for PJI were retrospectively reviewed. Synovial fluid was collected for LE measurement during surgery before arthrotomy in 79 procedures. Receiver operating characteristic curves were generated. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve (AUC) of LE, CRP, ESR, and CRP + ESR were calculated. RESULTS: Sensitivity, specificity, positive predictive value, and negative predictive value of the LE assay were 82%, 99%, 90%, and 97%, respectively. Receiver operating characteristic analysis revealed an LE threshold of 1.5 between the first (negative) and the second (positive) level of the ordinal variable, so that a grade starting from 1+ was accurate for a diagnosis of persistent infection (AUC 0.9044). The best thresholds for the CRP and the ESR assay were 8.25 mg/L (82% sensitivity, 84% specificity, AUC 0.8416) and 45 mm/h (55% sensitivity, 87% specificity, AUC 0.7493), respectively. CONCLUSION: The LE strip test proved a reliable tool to diagnose persistence of infection and outperformed the serum CRP and ESR assays. The strip test provides a valuable intraoperative diagnostic during second-stage revision for PJI.


Assuntos
Artroplastia de Quadril , Infecções Relacionadas à Prótese , Biomarcadores , Sedimentação Sanguínea , Proteína C-Reativa/análise , Hidrolases de Éster Carboxílico , Humanos , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/cirurgia , Reimplante , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Líquido Sinovial/química
8.
Ann Jt ; 7: 3, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38529157

RESUMO

Periprosthetic joint infection (PJI) is one of the major complications following arthroplasty implantation. Management of PJIs is a challenge for surgeons and various classification systems have been introduced, which consider variables such as onset of symptoms, pathogenesis and clinical manifestation. In an attempt to overcome the shortcomings which may limit their usefulness in borderline cases, a new classification system focusing on the topography of the infectious process has been proposed. This theory relies on the identification of the exact location of the bacterial colonization thus allowing to decide between a conservative or a more radical intervention irrespectively of the timing. The use of nuclear medicine device like radiolabelled white blood cells (WBC) scan could lead the path in identifying pathogenetic processes and their exact location thus guiding orthopaedic surgeons to the most appropriate diagnosis and treatment options. Currently management relies on debridement, antibiotics and implant retention (DAIR), which is traditionally performed at early stages, 1- or 2-stage revision arthroplasty which is commonly limited to chronic cases. Reports have demonstrated similar rates of infection recurrence following one and two-stage revisions, and the use of one-stage revision surgery is gaining popularity. More recently, satisfying results following partial implant retention during revision total arthroplasty for septic failures have been reported. In addition, in severe cases, definitive articulating antibiotic spacer, excision arthroplasty, arthrodesis or amputation can be performed.

9.
BMC Infect Dis ; 21(1): 416, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947342

RESUMO

BACKGROUND: Prosthetic joint infection (PJI) is one of the most feared complications following total arthroplasty surgeries. Gram-positive bacteria are the most common microorganisms implicated in PJIs, while infections mediated by fungi only account for 1% of cases. When dealing with PJIs, a two-stage revision arthroplasty is widely used. Briefly, a spacer is introduced until re-implantation of the definitive prosthesis to provide skeleton stabilization while delivering antibiotics in the site of the infection. Sometimes, antimicrobial therapy may fail, but the isolation of a second microorganism from the spacer is uncommon and even less frequent that of a yeast. CASE PRESENTATION: Here is described a case of a 75-year-old woman who underwent two-stage revision surgery of the left hip prosthesis secondary to a Staphylococcus capitis infection, whose spacer was found to be infected by Candida albicans at a later time. Briefly, the patient underwent revision surgery of the hip prosthesis for a suspected PJI. After the debridement of the infected tissue, an antibiotic-loaded spacer was implanted. The microbiological analysis of the periprosthetic tissues and the implant depicted a S. capitis infection that was treated according to the antimicrobial susceptibility profile of the clinical isolate. Three months later, the patient was admitted to the emergency room due to local inflammatory signs. Synovial fluid was sent to the laboratory for culture. No evidence of S. capitis was detected, however, a yeast was identified as Candida albicans. Fifteen days later, the patient was hospitalized for the removal of the infected spacer. Microbiological cultures confirmed the results of the synovial fluid analysis. According to the susceptibility profile, the patient was treated with fluconazole (400 mg/day) for 6 months. Seven months later, the patient underwent second-stage surgery. The microbiological tests on the spacer were all negative. After 12 months of follow-up, the patient has fully recovered and no radiological signs of infection have been detected. CONCLUSIONS: Given the exceptionality of this complication, it is important to report these events to better understand the clinical outcomes after the selected therapeutic options to prevent and forestall the development of either bacterial or fungal spacer infections.


Assuntos
Candidíase/cirurgia , Prótese de Quadril/efeitos adversos , Infecções Relacionadas à Prótese/microbiologia , Infecções Relacionadas à Prótese/cirurgia , Infecções Estafilocócicas/cirurgia , Idoso , Antibacterianos/uso terapêutico , Artroplastia de Quadril , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Feminino , Humanos , Reoperação , Infecções Estafilocócicas/microbiologia , Staphylococcus capitis/patogenicidade
10.
Expert Rev Anti Infect Ther ; 19(7): 945-948, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33198531

RESUMO

OBJECTIVES: We conducted a retrospective study to evaluate the outcomes of one-stage revision total knee arthroplasty (TKA) in terms of eradication of the infection, improvement of pain, and knee function. METHODS: Between 2009 and 2016, 20 patients underwent one-stage revision TKA for the treatment of a prosthetic joint infection (PJI). Inclusion criteria were: patients nonimmunocompromised with minimal or moderate bone loss, known organisms with known sensitivity. Assessment included clinical signs of infection eradication, range of motion, Knee Society clinical rating score, visual analog scale pain score, and radiographic assessment. RESULTS: After a mean follow-up of 6.2 years (range, 2-10 years), none of the patients had signs suggesting recurrent infection. Follow-up examination showed significant improvement of all variables compared to preoperative values (p < 0.001). CONCLUSIONS: One-stage revision surgery provides infection eradication and satisfying subjective functional outcomes for infected knee arthroplasty in selected patients. EXPERT OPINION: One-stage revision knee arthroplasty is a valuable resource to approach PJIs in selected patients whose infecting micro-organism and sensitivity are determined before surgery. In order to succeed strict inclusion criteria should be applied, as only non-immunocompromised patients with healthy soft tissues with minimal or moderate bone loss are eligible for this procedure.


Assuntos
Artroplastia do Joelho/efeitos adversos , Dor/etiologia , Infecções Relacionadas à Prótese/cirurgia , Idoso , Artroplastia do Joelho/métodos , Feminino , Seguimentos , Humanos , Articulação do Joelho/microbiologia , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Dor/cirurgia , Medição da Dor , Infecções Relacionadas à Prótese/diagnóstico , Amplitude de Movimento Articular , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
11.
Orthop Traumatol Surg Res ; 105(2): 237-240, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30497888

RESUMO

INTRODUCTION: Periprosthetic shoulder infections (PSIs) represent a serious complication following shoulder arthroplasty. No consensus exists regarding the optimal option. We conducted a retrospective case-control study to compare the outcomes of 2-stage revision shoulder arthroplasty and those of definitive articulating antibiotic spacer implantation with regards to eradication of the infection, improvement of pain and shoulder function. MATERIALS AND METHODS: Thirty patients treated for an infected shoulder arthroplasty were retrospectively reviewed after a mean follow-up of 8 years (range, 2-10 years). Nineteen underwent definitive articulating antibiotic spacer implantation and 11 underwent 2-stage revision arthroplasty. Mean age at surgery was 68.8 years. Assessment included Constant-Murley score, visual analog scale pain score, objective examination, patient subjective satisfaction score as well as standard radiographs. RESULTS: At the most recent follow-up, none of the patients had clinical or radiographic signs suggesting recurrent infection. Most patients reported satisfying subjective and objective outcomes. Follow-up examination showed significant improvement of all variables compared to preoperative values (p<0.001). Radiographs did not show progressive radiolucent lines or change in the position of the functional spacer. No statistically significant differences were reported between the two groups concerning Constant-Murley and VAS scores, while average forward flexion and abduction were significantly higher in patients undergoing 2-stage revision surgery. CONCLUSIONS: Both surgical procedures provided infection eradication and satisfying subjective functional outcomes. Functional results were superior in patients treated with revision shoulder prosthesis, although a higher rate of complication was reported in this cohort of patients, thus suggesting the use of permanent spacer in high-risk or low-demanding elderly patients. LEVEL OF EVIDENCE: III, Retrospective case-control study.


Assuntos
Antibacterianos/farmacologia , Artrite Infecciosa/cirurgia , Artroplastia/efeitos adversos , Materiais Revestidos Biocompatíveis , Infecções Relacionadas à Prótese/cirurgia , Prótese de Ombro/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/fisiopatologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/fisiopatologia , Radiografia , Amplitude de Movimento Articular , Reoperação/métodos , Estudos Retrospectivos , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/fisiopatologia , Articulação do Ombro/cirurgia
12.
Arch Orthop Trauma Surg ; 139(3): 317-322, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30374532

RESUMO

Periprosthetic joint infection (PJI) is a relatively frequent and devastating complication following prosthetic joint implantation. Several classification systems have been presented by various authors and are routinely used in clinical practice to help in early diagnosis and treatment. The most widely accepted classifications of periprosthetic infections rely on the timing of clinical presentation. Unfortunately, these schemes possess important shortcomings which limit their usefulness in clinical practice, as data reported in literature are contrasting, with success rate ranging from 60 to 80%, irrespectively of prosthetic infection timing. An attempt is made by us to update the current knowledge on PJIs by looking them from a different perspective, introducing a topographic principle in their classification. Our approach is based on the theory that identifying the exact location of the bacterial colonization may allow to decide whether to conservatively treat the patient or to perform a more radical intervention. The aim is to improve the understanding of the aetiology of this serious complication, lead to the appropriate treatment strategy according to the stage of the disease thus enhancing the outcomes of surgical management. Such a strategy, if widely accepted, could guide research studies on the management of PJIs. The availability of investigations like scintigraphy could aid in identifying pathogenetic processes and their exact location, which may be missed on conventional radiographs, and could enable orthopaedic surgeons to have a better understanding of PJI patterns.


Assuntos
Prótese Articular/efeitos adversos , Infecções Relacionadas à Prótese , Humanos , Infecções Relacionadas à Prótese/classificação , Infecções Relacionadas à Prótese/diagnóstico por imagem , Infecções Relacionadas à Prótese/terapia
13.
Arch Orthop Trauma Surg ; 138(5): 605-609, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29335894

RESUMO

INTRODUCTION: Management of periprosthetic shoulder infections (PSIs) still remains challenging. We conducted a retrospective case study to assess the outcomes of definitive articulating antibiotic spacer implantation in a cohort of elderly, low-demanding patients. We hypothesized that in patients with low functional demands seeking pain relief with chronic PSIs, treatment with a definitive articulating antibiotic spacer would lead to satisfying results concerning eradication of the infection, improvement of pain, and improving shoulder function. MATERIALS AND METHODS: 19 patients underwent definitive articulating antibiotic spacer implantation for the treatment of an infected shoulder arthroplasty. Mean age at surgery was 70.2 years. Patients were assessed pre-operatively with functional assessment including Constant-Murley score, and objective examination comprehending ROM, visual analog scale pain score, and patient subjective satisfaction (excellent, good, satisfied, or unsatisfied) score. Radiographs were taken to examine signs of loosening, and change in implant positioning. RESULTS: At the most recent follow-up, none of the patients had clinical or radiographic signs suggesting recurrent infection. Most patients reported satisfying subjective and objective outcomes. Follow-up examination showed significant improvement of all variables compared to pre-operative values (p < 0.001). Radiographs did not show progressive radiolucent lines or change in the position of the functional spacer. In one case, glenoid osteolysis was reported, which did not affect the clinical outcome. CONCLUSIONS: In selected elderly patients with low functional demands seeking pain relief with infected shoulder arthroplasty, definitive management with a cement spacer is a viable treatment option that helps in eradicating shoulder infection and brings satisfying subjective and objective outcomes. LEVEL OF EVIDENCE: Case series, Level IV.


Assuntos
Antibacterianos , Artroplastia , Prótese Articular , Infecções Relacionadas à Prótese , Ombro/cirurgia , Idoso , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Artroplastia/instrumentação , Artroplastia/métodos , Humanos , Infecções Relacionadas à Prótese/tratamento farmacológico , Infecções Relacionadas à Prótese/cirurgia , Estudos Retrospectivos , Articulação do Ombro/cirurgia
14.
Ann N Y Acad Sci ; 1074: 315-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17105927

RESUMO

In previous studies it was demonstrated that amphetamine derivatives and 1-methyl article-4-phenylpyridinium produce neuronal cell bodies. In the present work, we compared the fine ultrastructure of the intracellular inclusions induced by these different neurotoxic treatments. In particular, we compared the dynamical changes occurring when a mild toxic stimulus acts for different time intervals. For this purpose, we exposed catecholamine-synthesizing PC12 cells to different amphetamine derivatives (methamphetamine and 3,4-methylenedioxymethamphetamine), or 1-methyl-4-phenylpyridinium ion, which represents the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,3,4,6-tetrahydropyridine. Despite inclusions that are elicited by different mechanisms depending on the specific neurotoxin, their ultrastructural features are similar and there is a high parallelism in their temporal evolution. This suggests that formation of inclusions is a multi-step process that might be elicited by different stimuli and, once triggered, leads to the same final effect.


Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Anfetaminas/farmacologia , Corpos de Inclusão/ultraestrutura , Neurotoxinas/farmacologia , Animais , Células PC12 , Ratos
15.
J Dairy Res ; 70(2): 189-97, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12800873

RESUMO

Acid-precipitated rabbit 'whole casein' was digested by trypsin, chymotrypsin, pepsin, and clostripain to screen for possible peptides with antibacterial properties. The peptide fragments were separated by reversed-phase chromatography. The collected fractions were pooled and their antibacterial properties tested against Escherichia coli, Bacillus subtilis and Staphylococcus lentus. Three antibacterial peptide fragments derived from tryptic digestion of rabbit casein were isolated and identified. Their sequences were found as follows: HVEQLLR (residues 50-56 of beta-casein), ILPFIQSLFPFAER (residues 64-77 of beta-casein), and FHLGHLK (residues 19-25 of alpha(s1)-casein). The three peptides were synthesized and found to exert antibacterial effect against gram positive bacteria only. Proteolytic digestion of rabbit casein by chymotrypsin, pepsin and clostripain yielded several peptide fragments with antibacterial activity. Since antibiotic peptides can be released from casein during the digestion of milk proteins, our results suggest a possible antibacterial function of rabbit caseins. It is conceivable that antibacterial peptides can be generated by endopeptidases of the mammalian gastrointestinal tract possibly providing protection for new-born rabbits against aggression of micro-organisms.


Assuntos
Antibacterianos/farmacologia , Caseínas/química , Leite/química , Fragmentos de Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Bacillus subtilis/efeitos dos fármacos , Caseínas/metabolismo , Caseínas/farmacologia , Quimotripsina/metabolismo , Cisteína Endopeptidases/metabolismo , Escherichia coli/efeitos dos fármacos , Feminino , Pepsina A/metabolismo , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Coelhos , Staphylococcus/efeitos dos fármacos , Tripsina/metabolismo
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