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Biomedical subjects

A Murcia

Publications and source records attributed to A Murcia.

12 recordsLinked to original sources
PubMed2002

Filling of segmental bone defects in revision knee arthroplasty using morsellized bone grafts contained within a metal mesh.

For revision knee surgery with uncontained tibial bone defects, the authors report the containment of compacted morsellized allograft using metal-wire mesh, followed by implantation of a cemented total knee prosthesis. This method is comparable to the "impaction grafting technique" described for revision hip surgery and could be an alternative to metal wedges, augmented components, custom-made implants, polymethyl-methacrylate or structural bone grafts to solve some problems of cavitary and segmental bone defects in revision total knee arthroplasty.

Adult↗
PubMed2000

The midvastus surgical approach in total knee arthroplasty.

We report a study of 2 surgical approaches to the knee in 42 consecutive patients undergoing a total arthroplasty. They were divided into 2 groups. In Group 1 (n=17) the knee was exposed through classic medial parapatellar arthrotomy and in Group 2 (n=25) the knee was approached through the fibers of the medial vastus. Preoperative assessment did not reveal any statistical differences between the groups, and blood loss, operation time, biochemistry values and radiographic evaluation were also similar. However, a higher number of lateral releases, a loss of knee extension and a reduced range of motion were significantly associated with classical parapatellar arthrotomy. As the number of operative or postoperative complications was not increased, we recommend the mid-vastus approach for total knee arthroplasty.

Aged↗
PubMed1998

Influence of intramedullary versus extramedullary alignment guides on final total knee arthroplasty component position: a radiographic analysis.

A prospective study of 116 consecutive Kinemax cemented posterior cruciate ligament-retaining total knee arthroplasties was carried out. Similar surgical technique was used with a single variable: 61 were implanted using intramedullary guides on the tibia and 55 were implanted using extramedullary guides on the tibia. A radiographic study was performed after at least 1 year of follow-up to evaluate postoperative component position and compare the difference in the accuracy of positioning of the femoral and tibial components. Radiographic analysis showed that satisfactory position was achieved using both types of instrumentation. No statistically significant difference was observed in either the coronal or sagittal plane of the femoral component and the sagittal plane positioning of the tibial component. However, the coronal plane positioning of the tibial component revealed a statistically significant difference (P < .01), with intramedullary guides being superior to extramedullary guides. Also observed, was that using either technique, patients with less accurate postoperative positioning tended to be obese, with wide intramedullary canals. Patients with significant extraarticular deformities, marked bowing, and those with prior surgery or fractures may not be suitable for intramedullary guides, and they may require the use of extramedullary guides and intraoperative radiographic control. The ideal indication for the use of intramedullary instrumentation is in the patient who is not obese, with no extraarticular deformity, and with a well-defined, but not excessively wide, tibial medullary canal. Since tibial component malalignment in general, and coronal plane malalignment in particular, may adversely affect the long-term survival of total knee arthroplasties, the use of intramedullary alignment instrumentation is recommended when possible.

Aged↗
PubMed1998

Immunohistochemical analysis of mechanoreceptors in the human posterior cruciate ligament: a demonstration of its proprioceptive role and clinical relevance.

Although long-term studies report successful results with total knee arthroplasty (TKA), performed with or without posterior cruciate ligament (PCL) retention, controversy exists as to which is preferable in regard to patient outcome and satisfaction. The possible proprioceptive role of the PCL may account for a more normal feeling of the arthroplasty. Although the PCL has been examined using various histological techniques, immunohistochemical techniques are the most sensitive for neural elements. Therefore an immunohistochemical study was designed to determine the patterns of innervation, the morphological types of the proprioceptors, and their immunohistochemical profile. During TKA, samples were obtained from 22 osteoarthritic PCLs and subjected to immunohistochemical analysis with mouse monoclonal antibodies against neurofilament protein (NFP), S100 protein (S100P), epithelial membrane antigen (EMA), and vimentin (all present in neuromechanoreceptors). Three normal PCLs from cadaveric specimens were also obtained and analyzed for comparison. Five types of sensory corpuscles were observed in both the normal and the arthritic PCLs: simple lamellar, Pacini-like, Ruffini, Krause-like, and morphologically unclassified. Their structure included a central axon, inner core, and capsule in lamellar and Pacini corpuscles and variable intracorpuscular axons and periaxonal cells in the Ruffini and Krause-like corpuscles. The immunohistochemical profile showed the central axon to have NFP immunoreactivity, periaxonal cells to have S100P and vimentin immunoreactivity, and the capsule to have EMA and vimentin immunoreactivity. Nerve fibers and free nerve endings displayed NFP and S100P immunoreactivity. The immunohistochemical profile of the PCL sensory corpuscles is almost identical to that of cutaneous sensory corpuscles. Some prior histological studies of the PCL reported Golgi-like mechanoreceptors, and others found encapsulated corpuscles but no Golgi-like structures. This report determined the innervation of the PCL by the more sensitive immunohistochemical means, revealing four major types of encapsulated mechanoreceptors. The plentiful and varied types of encapsulated mechanoreceptors found in even the arthritic PCL suggests a rich proprioceptive role. It is controversial as to whether preservation of the PCL at TKA improves postoperative proprioception. Our findings tend to support those clinical reports of improved proprioception after PCL-retaining versus PCL-substituting TKAs. The presence of many and varied types of mechanoreceptors may account for the improved stair climbing reported in patients with PCL-retaining TKA and may contribute to patient satisfaction and a more normal feeling after TKA.

Arthroplasty, Replacement, Knee↗
PubMed1996

An evaluation of the antioxidant and antiviral action of extracts of rosemary and Provençal herbs.

Extracts of herbs and spices are increasingly of interest in the food industry because they retard oxidative degradation of lipids. There is also increasing interest in the antiviral activity of plant products. A liquid, deodorized rosemary extract and an oily extract of a mixture of Provençal herbs were tested for antioxidant and antiviral action in vitro. The rosemary extract (Herbor 025) and the extract of Provençal herbs (Spice Cocktail) inhibited peroxidation of phospholipid liposomes with 50% inhibition concentration values of 0.0009% (v/v) and 0.0035% (v/v), respectively. Herbor 025 and the spice cocktail (at 0.2%, v/v) reacted with trichloromethylperoxyl radical with calculated rates of 2.7 x 10(4) s-1 and 1.5 x 10(3) s-1, respectively. The main active components in the herbal preparations, carnosol and carnosic acid, at 0.05% (v/v) react with rate constants of (1-3) x 10(6) M-1 sec-1 and 2.7 x 10(7) M-1 sec-1, respectively. Both extracts show good antioxidant activity in the Rancimat test, especially in lard. Herbor 025 and the spice cocktail inhibited human immunodeficiency virus (HIV) infection at very low concentrations which were also cytotoxic. However, purified carnosol exhibited definite anti-HIV activity at a concentration (8 microM) which was not cytotoxic. Both preparations promoted some DNA damage in the copper-phenanthroline and the bleomycin-iron systems. The two herbal preparations possess antioxidant properties that may make them useful in the food matrix.

Abietanes↗
PubMed1994

Antioxidant actions of thymol, carvacrol, 6-gingerol, zingerone and hydroxytyrosol.

Antioxidants minimize oxidation of the lipid components in foods. There is an increasing interest in the use of natural and/or synthetic antioxidants in food preservation, but it is important to evaluate such compounds fully for both antioxidant and pro-oxidant properties. The properties of thymol, carvacrol, 6-ginerol, hydroxytyrosol and zingerone were characterized in detail. Thymol, carvacrol, 6-gingerol and hydroxytyrosol decreased peroxidation of phospholipid liposomes in the presence of iron(III) and ascorbate, but zingerone had only a weak inhibitory effect on the system. The compounds were good scavengers of peroxyl radicals (CCl3O2; calculated rate constants > 10(6) M-1 sec-1) generated by pulse radiolysis. Thymol, carvacrol, 6-gingerol and zingerone were not able to accelerate DNA damage in the bleomycin-Fe(III) system. Hydroxytyrosol promoted deoxyribose damage in the deoxyribose assay and also promoted DNA damage in the bleomycin-Fe(III) system. This promotion was inhibited strongly in the deoxyribose assay by the addition of bovine serum albumin to the reaction mixtures. Our data suggest that thymol, carvacrol and 6-gingerol possess useful antioxidant properties and may become important in the search for 'natural' replacements for 'synthetic' antioxidant food additives.

Antioxidants↗
PubMed1979

Reproducibility of an indirect immunofluorescent-antibody technique for capsular serotyping of Klebsiella pneumoniae.

Reproducibility of capsular serotypes of 55 consecutive clinical isolates of Klebsiella pneumoniae was evaluated by an indirect immunofluorescent-antibody technique previously described by Riser et al. (J. Clin. Pathol. 29: 296-304, 1976) Five colonies per specimen were examined for colony-to-colony variation, day-to-day variation, and reader-to-reader variation. Seventy-two reference strains were tested with each of 18 pools and 72 specific antisera prior to the clinical specimens to determine antiserum specificity and cross-reaction patterns. Lot-to-lot variation was examined with the reference strains. There was minimal lot-to-lot variation among the antisera tested. Ten antiserum pools required supplementation with individual antisera. The patterns of supplementation may vary from lot to lot. Colony-to-colony variation in intensity of immunofluorescence occurred, but there was no variation in serotype. These findings differ from previously reported colonial variation which occurred when API 20E biotypes were determined for individual colonies of K. pneumoniae directly from clinical specimens. Eighteen percent of clinical isolates studied gave cross-reactions when tested with the indicated specific antiserum. All but one of the cross-reactions were resolved with further dilutions. Day-to-day and reader-to-reader variations were minimal. The immunofluorescent-antibody technique is a reliable and reproducible method for capsular serotype determination. Capsular serotypes are less variable than API biotypes since colony-to-colony variation of serotype does not occur.

Cross Reactions↗
PubMedDate not supplied

Prophylaxis in transurethral surgery: oral lomefloxacin versus intravenous cefuroxime.

A randomized study compared the efficacy of a single dose of lomefloxacin given orally vs. cefuroxime given intravenously for prophylaxis against urinary tract infection in patients who were undergoing transurethral surgery. Patient groups were demographically similar; 25 received 400 mg lomefloxacin orally 2-6 h before surgery and 26 received 1.5 g cefuroxime intravenously 30-90 min before surgery. Urine cultures were obtained prior to surgery, 24 h after surgery and 3-5 days after surgery or before hospital discharge. Treatment was considered successful if bacterial culture showed < 10(5) CFU/ml. Clinical results expressed as success/failure rates showed success in 18 patients in the lomefloxacin group (72%) and 15 patients in the cefuroxime group (57.7%). Results demonstrated that lomefloxacin is superior to cefuroxime when used as prophylaxis against urinary tract infection following transurethral surgery. In addition, lomefloxacin may be preferable because of its convenient single-dose oral administration.

Administration, Oral↗