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1.
Scott P. Noel MS Harry S. Courtney PhD Joel D. Bumgardner PhD Warren O. Haggard PhD 《Clinical orthopaedics and related research》2010,468(8):2074-2080
Background
Open orthopaedic wounds are ideal sites for infection. Preventing infection in these wounds is critical for reducing patient morbidity and mortality, controlling antimicrobial resistance and lowering the cost of treatment. Localized drug delivery has the potential to overcome the challenges associated with traditional systemic dosing. A degradable, biocompatible polymer sponge (chitosan) that can be loaded with clinician-selected antibiotics at the point of care would provide the patient and clinician with a desirable, adjunctive preventive modality.Questions/purposes
We asked (1) if an adaptable, porous chitosan matrix could absorb and elute antibiotics for 72 hours for potential use as an adjunctive therapy to débridement and lavage; and (2) if the sponges could elute levels of antibiotic that would inhibit growth of Staphylococcus aureus and Pseudomonas aeruginosa?Methods
We fabricated a degradable chitosan sponge that can be loaded with antibiotics during a 60-second hydration in drug-containing solution. In vitro evaluation determined amikacin and vancomycin release from chitosan sponges at six time points. Activity tests were used to assess the release of inhibitory levels of amikacin and vancomycin.Results
Amikacin concentration was 881.5 μg/mL after 1 hour with a gradual decline to 13.9 μg/mL after 72 hours. Vancomycin concentration was 1007.4 μg/mL after 1 hour with a decrease to 48.1 μg/mL after 72 hours. Zone of inhibition tests were used to verify inhibitory levels of drug release from chitosan sponges. A turbidity assay testing activity of released amikacin and vancomycin indicated inhibitory levels of elution from the chitosan sponge.Clinical Relevance
Chitosan sponges may provide a potential local drug delivery device for preventing musculoskeletal infections. 相似文献2.
Alex McLaren MD Morgan B. Giers PhD James Fraser MD MPH Luke Hosack MD Michael R. Caplan PhD Ryan McLemore PhD 《Clinical orthopaedics and related research》2014,472(11):3324-3329
Background
Tissue distribution after local delivery has been quantified over a period of 5 hours on 7-T MRI in a rabbit model using gadolinium-labeled diethylenetriamine pentaacetic acid (Gd-DTPA) as an antimicrobial surrogate; however, it is unknown how the Gd-DTPA load in a local depot will affect the duration of high-concentration Gd-DTPA in local tissues after surgical débridement.Questions/purposes
We determined whether the Gd-DTPA load in bone cement affected its local tissue distribution over a period of 1 month after local delivery.Methods
A 1-cm3 soft tissue dead space was created in the quadriceps of seven rabbits and filled with gadolinium-loaded bone cement. At 7, 14, and 33 days, the volume of tissue with a Gd-DTPA concentration of more than 14 μg/mL was calculated from T1-weighted images using 7-T MRI. Differences in volumes of distribution were analyzed with ANOVA.Results
The volume of tissue with more than 14 μg/mL Gd-DTPA was much larger from higher gadolinium loads on Day 7 (p = 0.02) (2121 mm3 for 10 g and 665 mm3 for 1 g) and smaller with time for the 10-g formulation (2121 mm3 on Day 7 and 1241 mm3 on Day 14).Conclusions
Volume of distribution and duration of Gd-DTPA after local delivery increased with increasing load in the cement and decreased with time.Clinical Relevance
For local delivery, high antimicrobial concentrations would be expected in greater volumes of tissue, for longer durations, when higher antimicrobial loads are used. 相似文献3.
Ryan B. Miller MD Alex C. McLaren MD Christine Pauken PhD Henry D. Clarke MD Ryan McLemore PhD 《Clinical orthopaedics and related research》2013,471(1):195-200
Background
Local delivery of antifungals is an important modality in managing orthopaedic fungal infection. Voriconazole is a powder antifungal suitable for addition to bone cement that is released from bone cement but the mechanical properties of antimicrobial-loaded bone cement (ALBC) made with voriconazole are unknown.Questions/Purposes
(1) Is voriconazole release dose-dependent? (2) Is released voriconazole active? (3) Is the loss of ALBC’s compressive strength caused by voriconazole dose- and elution-dependent?Methods
Sixty standard test cylinders were fabricated with ALBC: 300 or 600 mg voriconazole per batch eluted for 30 days in deionized water. Voriconizole concentration in the eluate was measured using high-performance liquid chromatography. Cumulative-released voriconizole was calculated. Biologic activity was tested. Compressive strength was measured before and after elution. The effect of dose and time on release and compressive strength were analyzed using repeated-measure analysis of variance.Results
Fifty-seven percent and 63% of the loaded voriconazole were released by Day 30 for the 300-mg and 600-mg formulations, respectively. The released voriconazole was active on bioassay. Compressive strength was reduced from 79 MPa to 53 MPa and 69 MPa to 31 MPa by 30 days for the 300-mg and 600-mg formulations, respectively.Conclusions
Voriconazole release from ALBC increases with dose and is bioactive. Loss in compressive strength is greater after elution and with higher dose.Clinical Relevance
Three hundred milligrams of voriconazole in ALBC would be expected to deliver meaningful amounts of active drug in vivo. The compressive strength of ALBC with 600 mg voriconazole is less than expected compared to commonly used antibacterials. 相似文献4.
Daniel Guenther Alexandra Oks Max Ettinger Emmanouil Liodakis Maximilian Petri Christian Krettek Michael Jagodzinski Carl Haasper 《International orthopaedics》2013,37(8):1605-1611
Purpose
Collagen I hydrogels are widely used as scaffolds for regeneration of articular cartilage defects. We hypothesised that ingrowth might be improved by removing the superficial layer of a compressed hydrogel. The control group consisted of the original unmodified product.Methods
The migration of human bone marrow stromal cells (hBMSCs) into the hydrogel was evaluated by confocal microscopy. We quantified the DNA concentration of the hydrogel for each group and time point and evaluated the chondrogenic differentiation of cells.Results
After one week, the detectable amount of cells at the depth of 26–50 μm was significantly higher in the modified matrix (MM) than in the non-modified matrix (NM) (p = 0.011). The maximum depth of penetration was 75 μm (NM) and 200 μm (MM). After three weeks, the maximum depth of penetration was 175 μm (NM) and 200 μm (MM). Likewise, at a depth of 0–25 μm the amount of detectable cells was significantly higher in the MM group (p = 0.003). After 14 days, the concentration of DNA was significantly higher in the samples of the MM than in the control group (p = 0.000). Staining of histological sections and labelling with collagen II antibodies showed that a chondrogenic differentiation of cells in the scaffold can occur during in vitro cultivation.Conclusions
Removing the superficial layer is essential to ensuring proper ingrowth of cells within the compressed hydrogel. Compressed hydrogels contribute better to cartilage regeneration after surface modification. 相似文献5.
6.
Justin Roberts Josh Bingham Alex C. McLaren Ryan McLemore 《Clinical orthopaedics and related research》2015,473(7):2262-2269
Background
Liposomal amphotericin B is locally delivered to treat fungal orthopaedic infections but little is known about local tissue toxicity, if any, that might be associated with local delivery.Questions/purposes
(1) Is liposomal amphotericin B cytotoxic in vitro? (2) Is locally delivered liposomal amphotericin B toxic to tissue in vivo?Methods
Mouse fibroblasts (BA LB/3T3 A31) and osteoblasts (MC3T3) were exposed to two formulations of amphotericin B (liposomal and deoxycholate) at concentrations of 0, 1, 5, 10, 100, 500, and 1000 μg/mL. Cell viability was determined by MTT assay after 1, 3, and 5 hours of exposure and a proliferation assay after 1, 4, and 7 days of exposure and then after 3 recovery days without drug. Tissue exposure occurred by local delivery of liposomal amphotericin B, 200 or 800 mg/batch antifungal-loaded bone cement (ALBC), or amphotericin B deoxycholate, 800 mg/batch ALBC in rat paraspinal muscles. White blood cell count (WBC) and serum amphotericin B levels were obtained on Days 1 and 3. Rats were euthanized at 2 and 4 weeks and semiqualitative histopathology was performed.Results
Liposomal amphotericin B is cytotoxic in vitro but not toxic to tissues in vivo. All cells survived concentrations up to 1000 μg/mL for 5 hours, 100% ± 0%, but none survived ≥ 100 μg/mL for 7 days, 0% ± 0%. Fibrosis was seen adjacent to ALBC without inflammation or necrosis, indistinguishable from controls for both liposomal amphotericin B doses. Amphotericin B serum levels were all less than 1 µg/mL and WBC counts were all normal.Conclusions
In vitro cytotoxicity to liposomal amphotericin B occurred but no adverse tissue reaction was seen in vivo.Clinical Relevance
Local delivery of liposomal amphotericin B in ALBC was well tolerated by mouse tissue; however, clinical studies are needed to confirm this finding in humans. 相似文献7.
Hiroshi Takahashi Masashi Yamazaki Akihiko Okawa Tsuyoshi Sakuma Kei Kato Mitsuhiro Hashimoto Koichi Hayashi Takeo Furuya Takayuki Fujiyoshi Junko Kawabe Tomonori Yamauchi Chikato Mannoji Tomohiro Miyashita Ryo Kadota Masayuki Hashimoto Yasuo Ito Kazuhisa Takahashi Masao Koda 《European spine journal》2012,21(12):2580-2587
Objective
Granulocyte colony-stimulating factor (G-CSF) is a cytokine that is clinically used to treat neutropenia. G-CSF also has non-hematopoietic functions and could potentially be used to treat neuronal injury. To confirm the safety and feasibility of G-CSF administration for acute spinal cord injury (SCI), we have initiated a phase I/IIa clinical trial of neuroprotective therapy using G-CSF.Methods
The trial included a total of 16 SCI patients within 48 h of onset. In the first step, G-CSF (5 μg/kg/day) was intravenously administered for 5 consecutive days to 5 patients. In the second step, G-CSF (10 μg/kg/day) was similarly administered to 11 patients. We evaluated motor and sensory functions of patients using the American Spinal Cord Injury Association (ASIA) score and ASIA impairment scale (AIS) grade.Results
In all 16 patients, neurological improvement was obtained after G-CSF administration. AIS grade increased by one step in 9 of 16 patients. A significant increase in ASIA motor scores was detected 1 day after injection (P < 0.01), and both light touch and pin prick scores improved 2 days after injection (P < 0.05) in the 10 μg group. No severe adverse effects were observed after G-CSF injection.Conclusion
These results indicate that intravenous administration of G-CSF (10 μg/kg/day) for 5 days is essentially safe, and suggest that some neurological recovery may occur in most patients. We suggest that G-CSF administration could be therapeutic for patients with acute SCI. 相似文献8.
Sakuma T Yamazaki M Okawa A Takahashi H Kato K Hashimoto M Hayashi K Furuya T Fujiyoshi T Kawabe J Mannoji C Kadota R Hashimoto M Takahashi K Koda M 《European spine journal》2012,21(3):482-489
Objective
Based on the neuroprotective effects of granulocyte colony-stimulating factor (G-CSF) on experimental spinal cord injury, we initiated a clinical trial that evaluated the safety and efficacy of neuroprotective therapy using G-CSF for patients with worsening symptoms of compression myelopathy.Methods
We obtained informed consent from 15 patients, in whom the Japanese Orthopaedic Association (JOA) score for cervical myelopathy decreased two points or more during a recent 1-month period. G-CSF (5 or 10 μg/kg/day) was intravenously administered for five consecutive days. We evaluated motor and sensory functions of the patients and the presence of adverse events related to G-CSF therapy.Results
G-CSF administration suppressed the progression of myelopathy in all 15 patients. Neurological improvements in motor and sensory functions were obtained in all patients after the administration, although the degree of improvement differed among the patients. Nine patients in the 10-μg group (n = 10) underwent surgical treatment at 1 month or later after G-CSF administration. In the 10-μg group, the mean JOA recovery rates 1 and 6 months after administration were 49.9 ± 15.1 and 59.1 ± 16.3%, respectively. On the day following the start of G-CSF therapy, the white blood cell count increased to more than 22,700 cells/mm3. It varied from 12,000 to 50,000 and returned to preadministration levels 3 days after completing G-CSF treatment. No serious adverse events occurred during or after treatment.Conclusion
The results indicate that G-CSF administration at 10 μg/kg/day is safe for patients with worsening symptoms of compression myelopathy and may be effective for their neurological improvement. 相似文献9.
Background
Metal-on-metal bearing with cemented femoral component and cementless acetabular fixation is the current standard in surface replacement arthroplasty (RSA) of the hip. Because of concerns about the long-term survivorship of cemented stems in conventional hip arthroplasty, it seems logical to achieve cementless fixation on the femoral side with RSA.Questions/Purposes
The goals of this review were to evaluate clinical and radiological data reported from previously published cementless RSA series. In addition, we intend to review author’s preliminary experience with Conserve Plus cementless devices specifically assessing the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels measured in follow-up.Methods
A references search was done with PubMed using the key words “cementless hip resurfacing”, “cementless hip resurfacing prosthesis”, and “femoral cementless hip resurfacing”. Additionally, the clinical outcomes, the complications rate, the survivorship, and the metallic ions levels were measured in 94 cementless Conserve Plus© devices in 90 patients (68 males and 22 females) with a mean age of 41.1 years (18–59). Mean follow-up was 13.1 months (8–16).Results
No revision was performed during the observed follow-up. Neither radiological signs of loosening nor neck narrowing >10% were evident. Chromium and cobalt levels in whole blood samples rose respectively from 0.53 μg/l (0.1–1.7) to 1.7 μg/l (0.6–2.9) and from 0.54 μg/l (0.1–1.4) to 1.98 μg/l (0.1–2.8).Conclusions
Cementless “fit and fill” femoral-side fixation, which seems to be potentially evolved and design-related, should be considered for future hip-resurfacing device generations. 相似文献10.
Bernstein M Desy NM Petit A Zukor DJ Huk OL Antoniou J 《International orthopaedics》2012,36(9):1807-1812
Purpose
Long-term studies are required to support the use of metal-on-metal (MoM) bearings in total hip arthroplasty (THA) given the concern about systemic metal ion release and reports of adverse local soft tissue reactions. The purpose of this study was to report the seven to 13-year clinical, radiographic, and metal ion results in patients following MoM THA.Methods
We studied 163 prostheses after second-generation MoM THA between July 1997 and November 2003. Cobalt and chromium metal ions were collected using whole and analysed by inductively-coupled plasma-mass spectrometry.Results
The mean follow-up was 8.87 years (range, 7–13 years). Four hips (2.5 %) were revised. The Kaplan-Meier survivorship was 91.3 % for revision for all causes, and 97.5 % when excluding the hips revised for a manufacturer’s defect. Median whole blood cobalt levels peaked at a value of 2.87 μg/L at four years (p < 0.0001 vs. pre-operative) and subsequently decreased to 2.0 μg/L after nine years (p = 0.002 vs. four years). Median chromium levels maximally increased up to 0.75 μg/L after five years (p < 0.0001 vs. pre-operative) and tended to decrease thereafter to values of 0.56 μg/L after seven years.Conclusions
This seven to 13-year follow-up study indicates that the clinical and radiological results following MoM THA are satisfactory with low revision rates. Cobalt and chromium ion levels peaked at four and five years, respectively, and gradually decreased thereafter. 相似文献11.
Laumonier T Michel M Gabbiani G Hoffmeyer P Bochaton-Piallat ML Menetrey J 《International orthopaedics》2012,36(8):1733-1738
Purpose
The myofibroblast, a contractile fibroblastic cell expressing α-smooth muscle actin (α-SMA), has been reported to play a role in ligament healing. The aim of this study was to evaluate the feasibility of transplanting culture-derived myofibroblasts in injured rabbit medial collateral ligaments (MCL) and in intact anterior cruciate ligaments (ACL).Methods
Fibroblasts isolated from the iliotibial band were cultured in the presence of transforming growth factor beta-1 (TGF-β1) for five days and analysed for α-SMA expression. In a concentration of TGF-β1 ≥ 10 ng/ml, the differentiation rate into myofibroblast was 90%. After labelling with PKH26, α-SMA -positive cells were transplanted in intact ACL and in injured MCL of ten rabbits.Results
Survival of PKH-26+ cells was seen in all intact and damaged ligaments one day after injection. The density of PKH-26+ cells had decreased at seven days postinjection in both ligaments. Double-positive PKH-26+/α-SMA+ cells were only observed in injured MCL at seven days postinjection. Moreover, we found that genetically modified fibroblasts differentiate into myofibroblasts and can be transplanted into ligaments.Conclusions
Our data demonstrate that culture-born myofibroblasts survive and maintain α-SMA expression up to one week after transplantation. This study provides the first insight into the feasibility of transplanted mechanically active cells for ligament reconstruction. 相似文献12.
Ying X Cheng S Wang W Lin Z Chen Q Zhang W Kou D Shen Y Cheng X Peng L Zi Xu H Zhu Lu C 《International orthopaedics》2012,36(3):647-653
Purpose
Many in vitro studies of the analysis of the lactoferrin (LF) effect on cells have been reported. However, no study has yet investigated the effect of LF on osteogenic differentiation of human adipose-derived stem cells (hADSCs). The aim of this study was to evaluate the effect of LF on osteogenic differentiation of human adipose stem cells.Methods
The hADSCs were cultured in an osteogenic medium with 0, 10, 50 and 100 μg/ml LF, respectively. hADSC proliferation was analysed by Cell Counting Kit-8 (CCK-8) assay, and cell osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity assay, von Kossa staining and real-time polymerase chain reaction (RT-PCR).Results
Cell proliferation was significantly increased by LF in a dose-dependent manner from days 4 to 14. Cells cultured with 100 μg/ml LF presented a higher activity compared with the control. The deposition of calcium was increased after the addition of LF. The mRNA expression of type I collagen (COL-I), ALP, osteocalcin (OCN) and RUNX2 increased markedly as a result of LF treatment.Conclusions
We have shown for the first time that LF could promote the proliferation and osteogenic differentiation of hADSCs, which could be a promising approach for enhancing osteogenic capacity of cell-based construction in bone tissue engineering. 相似文献13.
Purpose
We evaluated the consequences of cobalt–chromium alloy (CoCr) wear debris challenge in the peri-spine region to determine the inflammation and toxicity associated with submicron particulates of CoCr-alloy and nickel on the peri-spine.Methods
The lumbar epidural spaces of (n = 50) New Zealand white rabbits were challenged with: 2.5 mg CoCr, 5.0 mg CoCr, 10.0 mg CoCr, a positive control (20.0 mg of nickel) and a negative control (ISOVUE-M-300). The CoCr-alloy and Ni particles had a mean diameter of 0.2 and 0.6 μm, respectively. Five rabbits per dose group were studied at 12 and 24 weeks. Local and distant tissues were analyzed histologically and quantitatively analyzed immunohistochemically (TNF-α and IL-6).Results
Histologically, wear particles were observed in all animals. There was no evidence of toxicity or local irritation noted during macroscopic observations in any CoCr-dosed animals. However, Ni-treated control animals experienced bilateral hind leg paralysis and were euthanized at Day 2. Histopathology of the Ni particle-treated group revealed severe neuropathy. Quantitative immunohistochemistry demonstrated a CoCr-alloy dose-dependent increase in cytokines (IL-6, TNF-α, p < 0.05) at 12 and 24 weeks.Conclusions
Subtle peri-spine inflammation associated with CoCr-alloy implant particles was dose dependent and persistent. Neuropathy can be induced by highly reactive Ni particles. This suggests peri-spine challenge with CoCr-alloy implant debris (e.g., TDA) is consistent with past reports using titanium alloy particles, i.e., mild persistent inflammation. 相似文献14.
Background
Matrix metalloproteinases are catabolic enzymes that play a key role in the articular cartilage degeneration evident in degenerative and inflammatory conditions of articular cartilage. The aim of this study is to assess the ability of pravastatin to modify matrix metalloproteinase (MMP) messenger RNA (mRNA) expression and enzyme activity in a culture of normal human chondrocytes stimulated by interleukin-1β.Materials and methods
Normal human chondrocytes were stimulated with interleukin (IL)-1β for 6 h to induce MMP expression, simulating a catabolic state, and then treated with pravastatin (1, 5 and 10 μM) for a further 18 h before cell lysates and supernatants were harvested. Cells stimulated with IL-1β but not treated with pravastatin served as controls. Real-time polymerase chain reaction (PCR) was used to assess expression of MMP-3 and MMP-9 mRNA. MMP enzyme activity was assessed using a fluorescent MMP-specific substrate. Statistical analysis was performed using analysis of variance (ANOVA).Results
MMP-3 and MMP-9 mRNA expression was reduced at all concentrations tested with statistically significant trends in reduction (p = 0.002 and <0.001, respectively). Analysis of culture supernatants revealed that pravastatin treatment led to a reduction in total MMP activity but not to a statistically significant degree (p = 0.07).Conclusions
Treatment with pravastatin of stimulated human chondrocytes leads to significant down-regulation of selected MMP genes and a non-significant reduction in MMP enzyme activity. Our results provide further evidence that statins may have a role to play in future treatment of disease affecting articular chondrocytes. 相似文献15.
Fatih Bayrakli Hatice Balaban Unal Ozum Cevdet Duger Suat Topaktas Hamit Zafer Kars 《European spine journal》2012,21(12):2588-2593
Purpose
To investigate the effect of an anti-TNF-α agent (etanercept) on recovery processes in a partial spinal cord injury (SCI) model using clinical and electrophysiological tests.Methods
Twenty-four New Zealand rabbits were divided into three groups: group 1 [SCI + 2 ml saline intramuscular (i.m.), n = 8], group 2 (SCI + 2.5 mg/kg etanercept, i.m., 2–4 h after SCI, n = 8) and group 3 (SCI + 2.5 mg/kg etanercept, i.m., 12–24 h after SCI, n = 8). Rabbits were evaluated before SCI, immediately after SCI, 1 week after, and 2 weeks after SCI, clinically by Tarlov scale and electrophysiologically by SEP.Results
Tarlov scores of groups 2 and 3 were significantly better than group 1, 2 weeks after SCI. SEP recovery was significantly better in groups 2 and 3 than group 1, 2 weeks after SCI.Conclusions
These results show that blocking TNF-α mediated inflammation pathway by an anti-TNF-α agent enhances clinical and electrophysiological recovery processes in partial SCI model. 相似文献16.
Dave Shukla James Fitzsimmons Kai-Nan An Shawn O’Driscoll 《International orthopaedics》2014,38(1):89-93
Purpose
Press-fit cementless radial head implant longevity relies on adequate bone ingrowth. Failed implant osseointegration remains a clinical concern and has been shown to lead to prosthetic failure. The purpose of this study was to test the hypothesis that implants with sufficient initial press-fit stability would be less likely to fail due to implant pull-out, as demonstrated by an increasing amount of energy required to remove the prosthesis from the canal.Methods
Ten cadaveric radii were implanted with five sizes (6–10 mm in 1-mm increments) of grit-blasted, cementless radial head stems. A customised slap hammer was used to measure the energy required to remove each stem. Stem-bone micromotion was also measured.Results
The suboptimally sized stem (Max − 1) (i.e. 1 mm undersized) required less energy (0.5 ± 0 J) to pull out than the optimally sized stem (Max) (1.7 ± 0.3 J) (p = 0.008). The optimally sized stem demonstrated greater initial stability (45 ± 7 μm) than the suboptimally sized stem (79 ± 12 μm) (p = 0.004).Conclusions
This investigation demonstrates the importance of obtaining adequate press-fit stability for the prevention of radial head stem pull-out failure. These data add to the relatively scant knowledge in the literature regarding radial head biomechanics. The energy required to remove a prosthetic radial head ingrowth stem decreases in conjunction with diameter. The use of an inadequately sized stem increases the stem’s micromotion as well as the risk of prosthetic loosening due to pull-out. 相似文献17.
Leah Gandee Jer-Tsong Hsieh Vanessa Sperandio Cristiano G. Moreira Chih-Ho Lai Philippe E. Zimmern 《International braz j urol : official journal of the Brazilian Society of Urology》2015,41(1):67-77
Purpose
The treatment of urinary tract infections (UTI) with antibiotics is commonly used, but recurrence and antibiotic resistance have been growing and concerning clinicians. We studied whether the rapid onset of a protective biofilm may be responsible for the lack of effectiveness of antibiotics against selected bacteria.Materials and Methods
Two established uropathogenic Escherichia coli strains, UTI89 and CFT073, and two Pseudomonas aeruginosa strains, PA01 and Boston-41501, were studied to establish a reliable biofilm formation process. Bacterial growth (BG) was determined by optical density at 600 nm (OD 600) using a spectrophotometer, while biofilm formation (BF) using crystal violet staining was measured at OD 550. Next, these bacterial strains were treated with clinically relevant antibiotics, ciprofloxacin HCl (200 ng/mL and 2 μg/mL), nitrofurantoin (20 μg/mL and 40 μg/mL) and ampicillin (50 μg/mL) at time points of 0 (T0) or after 6 hours of culture (T6). All measurements, including controls (bacteria -1% DMSO), were done in triplicates and repeated three times for consistency.Results
The tested antibiotics effectively inhibited both BG and BF when administered at T0 for UPEC strains, but not when the antibiotic administration started 6 hours later. For Pseudomonas strains, only Ciprofloxacin was able to significantly inhibit bacterial growth at T0 but only at the higher concentration of 2 μg/mL for T6.Conclusion
When established UPEC and Pseudomonas bacteria were allowed to culture for 6 hours before initialization of treatment, the therapeutic effect of selected antibiotics was greatly suppressed when compared to immediate treatment, probably as a result of the protective nature of the biofilm. 相似文献18.
Richard L. Kahn Jennifer Cheng James J. Bae Kara Fields John G. Muller John D. MacGillivray Howard A. Rose Riley J. Williams III Jacques T. YaDeau 《HSS journal》2015,11(3):236-242
Background
Previous work indicates that 30 mg isobaric mepivacaine 1.5% plus 10 μg fentanyl produces reliable anesthesia for knee arthroscopy with a more rapid recovery profile than 45 mg mepivacaine.Questions/Purposes
This randomized controlled trial compared plain mepivacaine to three reduced doses of mepivacaine with 10 μg fentanyl for spinal anesthesia.Methods
Following written informed consent, subjects undergoing outpatient knee arthroscopy were prospectively randomized into one of four groups: mepivacaine 37.5 mg (M37.5); mepivacaine 30 mg plus fentanyl 10 μg (M30/F10); mepivacaine 27 mg plus fentanyl 10 μg (M27/F10); and mepivacaine 24 mg plus fentanyl 10 μg (M24/F10). The spinal was evaluated by the blinded anesthetist and surgeon. In the post-anesthesia care unit, sensory and motor block resolution was assessed. Subjects rated their satisfaction with the overall experience.Results
Group M30/F10 (n = 6) had two “fair” anesthetics, and group M27/F10 (n = 10) had one “fair” and one “inadequate” anesthetic. Both groups were eliminated from further enrollment per study protocol. The recovery profiles showed little difference between groups M37.5 and M30/F10, except for motor block resolution (median (25th percentile, 75th percentile): 171 (135, 195) and 128 (120, 135), respectively). Groups M27/F10 and M24/F10 demonstrated recovery profiles that were faster than group M37.5. Patient satisfaction was 10/10 for all groups.Conclusions
Adding fentanyl 10 μg to a lower dose of mepivacaine 1.5% can lead to quicker recovery profiles. However, this advantage of a quicker recovery must be weighed against the likelihood of an incomplete anesthetic.Electronic supplementary material
The online version of this article (doi:10.1007/s11420-015-9454-8) contains supplementary material, which is available to authorized users. 相似文献19.
20.
Bin Ji Jixiang Shi Xiangyu Cheng Junjie Zhou Qiang Zhou Chengfu Cao Jinhui Pang 《International orthopaedics》2013,37(10):2061-2063