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Biomedical subjects

Antonio Herrera

Publications and source records attributed to Antonio Herrera.

At least 19 recordsLinked to original sources

Evaluation of GC-ion trap-MS/MS methodology for monitoring PCDD/Fs in infant formulas.

The application of high resolution gas chromatography in combination with low resolution mass spectrometry with electron ionization and MS/MS detection (HRGC-MS/MS) is tested for its use in the analysis of PCDD/Fs in infant formulas. Development of the analytical method was based upon EPA directrices and international recommendations. Calibration linearity was tested and average relative response for any native and labelled compound over the five-point calibration range below 14% was found. The precision and accuracy of the proposed analytical procedure are also presented. Results obtained are in agreement with EPA criteria. The method is applied to the analysis of a number of initial and follow-on milk based infant formulas. In general, HRGC-MS/MS constitutes an interesting method for the analysis of dioxins in such matrices.

Benzofurans↗

New easy approach to the synthesis of 2,5-disubstituted and 2,4,5-trisubstituted 1,3-oxazoles. The reaction of 1-(methylthio)acetone with nitriles.

The reaction of 1-(methylthio)acetone with different nitriles in the presence of triflic anhydride led to the one-pot formation of 2-substituted 5-methyl-4-methylthio-1,3-oxazoles in good yield. 1,2- and 1,4-Bisozaxolyl-substituted benzenes were obtained when the reaction was carried out using aromatic dinitriles. The methylthio group at the C4 position of the oxazole ring was easily removed with Raney nickel to form 2-substituted 5-methyl-1,3-oxazoles in good yields. 4-Methylsulfonyl derivatives were prepared by the oxidation of the MeS group with m-CPBA. The proposed mechanism for the formation of oxazoles involves an unstable 1-(methylthio)-2-oxopropyl triflate, which was detected from the low-temperature NMR spectra.

Acetone↗

Fracture of a ceramic femoral head after ceramic-on-ceramic total hip arthroplasty.

A case of fracture of the ceramic head of a total hip arthroplasty is presented, which was a total cementless arthroplasty with ceramic-on-ceramic articulation. No history of trauma was observed. The arthroplasty was revised, and a new cementless arthroplasty with a polyethylene insert and a metal head was inserted. The result has been satisfactory.

Adult↗

Management of types III and IV acetabular deficiencies with the longitudinal oblong revision cup.

Thirty-five longitudinal oblong revision (LOR) cups were used to reconstruct 29 type III and 6 type IV acetabular defects. Intraoperatively, we considered that cup contact was complete when we achieved a continuous contact between the cup periphery and the acetabular rim. When there were areas with a lack of contact, we considered that the contact was partial or incomplete. All patients were followed up for 4 to 8 years (mean = 6.3 years). At the latest follow-up, 30 cups were stable (85.8%) and 5 had migrated (14.2%). We found a significant relation between incomplete cup contact with the acetabular rim and subsequent failure (P = .042). The abduction angle was significantly increased in the group of unstable cups (P = .032) because of the migration of the acetabular component that became more vertical. Pain, limp, use of walking aids, functional level, and limb-length discrepancy significantly improved postoperatively (P < .0001). The Harris hip score improved from a mean preoperative score of 37 points to that of 79 points (P < .01). This implant showed satisfactory stability at early to midterm follow-up.

Acetabulum↗

Perioperative intravenous iron, with or without erythropoietin, plus restrictive transfusion protocol reduce the need for allogeneic blood after knee replacement surgery.

BACKGROUND: Unilateral total knee replacement (TKR) results in a substantial blood loss and 30 to 50 percent of patients receive allogeneic blood transfusion (ABT). Therefore, the effectiveness of a restrictive transfusion trigger (hemoglobin [Hb] level < 8 g/dL) plus stimulation of erythropoiesis was evaluated, with or without blood salvage, for reducing ABT in TKR patients. STUDY DESIGN AND METHODS: A series of 139 consecutive of primary TKR patients received perioperative iron sucrose (2 x 200 mg/48 hr, intravenously [IV]), plus preoperative erythropoietin (EPO; 1 x 40.000 UI, sc) if preoperative Hb level was less than 130 g per L (Group A). This protocol was applied to another series of 173 consecutive TKR patients who also received postoperative unwashed shed blood (USB) if preoperative Hb level was less than 130 g per L (Group B). Perioperative clinical and laboratory data were gathered. RESULTS: No adverse effects of iron sucrose, EPO, or USB administration were witnessed, and only 13 patients received ABT overall (4%). No major differences in perioperative blood counts or iron metabolism variables were observed between groups, but stimulation of erythropoiesis seemed to be more pronounced in those patients receiving EPO (p < 0.05). There were no differences in postoperative complications between groups, but length of hospital stay for patients with a preoperative Hb level of less than 130 g per L was shorter in Group B (p < 0.05). CONCLUSION: This blood saving protocol seems to be effective for reducing ABT in TKR patients. Which patients are more likely to benefit from either perioperative iron administration or selective addition of postoperative blood salvage to pharmacologic treatment, however, needs to be further evaluated.

Aged↗

Evaluation of residues of essential oil components in honey after different anti-varroa treatments.

Apiary trials on the use of three different treatments (Apilife Var, thymol solution in olive oil, and thymol solution in ethanol) for the control of Varroa destructor were conducted in Aragon (northeastern Spain). For the evaluation of the presence of residues of these treatments in honey an analytical method was developed. The method is applied to analyze honey samples before and after treatments with the acaricides mentioned. A solid-phase extraction on trifunctional silane SPE C18 cartridge and gas chromatography separation using a flame ionization detector allow reliable and precise determination of residues of thymol, menthol, eucalyptol, and camphor in honey. The results indicate that camphor is present in only low concentrations, residues of eucalyptol or menthol were not found at all, and only thymol left residues in high concentrations. Residues of thymol found in honey collected from the beehives ranged from 0.75 to 8.20 microg/g for Apilife Var, from 0.03 to 6.30 microg/g for thymol solution in olive oil, and from 0.05 to 6.20 microg/g for thymol solution in ethanol. Even so, natural treatments can be considered to be good alternatives for synthetic acaricides, especially because they do not represent a sanitary risk.

Animals↗

Epidemiology of osteoporotic hip fractures in Spain.

We conducted a multicentre study, divided into a retrospective and a prospective portion. The retrospective study evaluated osteoporotic hip fractures that occurred during 2002. The prospective study evaluated osteoporotic hip fractures that occurred during May 2003. The study was conducted in 77 hospitals in Spain and comprised patients 60 years of age and over. In the retrospective study we registered 13,195 hip fractures. Of the patients, 74% were women and 26% were men. The mean age was 80.7+/-8.4 years. The average incidence was 6.94+/-0.44 hip fractures per 1,000 inhabitants/year (95% CI, 6.07-7.82). In the prospective study, we registered 1,399 hip fractures. This represents a monthly incidence of 0.60+/-0.04 hip fractures per 1,000 inhabitants/year (95% CI, 0.51-0.69). Of the subjects, 74% were women and 26% were men. The mean age was 81.4+/-8.1 years. Using these data, we calculated the average annual prevalence in 2003 to be 7.20 fractures per 1,000 inhabitants. Thirty-three percent had previously suffered a hip fracture. Prior to the fracture, only 18% had received medical treatment for osteoporosis. After discharge from the hospital, only 26% were receiving pharmacological treatment for osteoporosis.

Aged↗

Spinal hydatidosis.

STUDY DESIGN: Retrospective study. OBJECTIVES: To revise the treatment of spinal hydatidosis. SUMMARY OF BACKGROUND DATA: About 50% of cases of bone hydatidosis are spinal. METHODS: Twenty patients with spinal hydatidosis were treated. There were 13 men and 7 women, with a mean age of 53.1 years. The median follow-up was 4.8 years. The infected area was the cervical spine in 1 patient, the dorsal spine in 7, the lumbar spine in 7, and the sacrum in 5. Curettage and resection of the infected bone were performed. The spine was exposed posteriorly in all but 2 patients. An additional posterior decompression and fusion with instrumentation were performed after removing the involved posterior elements in 8 patients. An anterior approach was used in 2 patients: a total corpectomy was performed and a bone graft was added. Two weeks later, a posterior decompression and fixation with instrumentation was done. No preoperative drugs were used. Medical antihelmintic treatment was used after surgery in all but 8 patients. RESULTS: Thirteen patients had spinal cord injury at the moment of surgery. The neurologic damage recovered only in 1 case. Repeated curettage was necessary in 13 cases: in 12 of them because of recurrence and in 1 because of surgical wound infection. In 6 cases of recurrence, there was also chronic wound infection. At last follow-up, 17 patients were free of disease. CONCLUSIONS: The treatment of choice of spinal hydatidosis is surgical removal of the affected vertebrae combined with posterior stabilization, followed by postoperative adjuvant chemotherapy. Recurrence is very frequent.

Adult↗

Determination of pesticides and PCBs in virgin olive oil by multicolumn solid-phase extraction cleanup followed by GC-NPD/ECD and confirmation by ion-trap GC-MS.

A multicolumn solid-phase extraction cleanup for the determination of organophosphorus (OP) and organochlorine (OC) pesticides plus PCB congeners in virgin olive oil is presented. The method involves dissolution of the olive oil in hexane, followed by a cleanup system using a diatomaceous earth column (Extrelut-QE) with reversed (C(18)) and normal (alumina) phase SPE columns. Determination of OPs was by GC-NPD, while the OCs and PCBs were analyzed using GC-ECD. Recovery assays for OPs varied from 81.7% to 105.3%, for OCs ranged between 74.3% and 99.4%, while for PCBs were from 60.1% to 119.2%. Quantitation limits ranged from 10 to 25 microg/kg olive oil for OPs, and from 1 to 6 microg/kg olive oil for OCs and PCBs. In the case of positive samples, the confirmation of pesticide identity was performed by ion-trap GC-MS/MS. The applicability of the method was assayed with 19 virgin olive oil samples collected from different olive mills of Aragón (Spain). Only one OP pesticide (acephate) was detected in one sample at a concentration of 10 microg/kg. Organochlorine pesticides were found in 5-47% of samples at very low levels ranging from 1.5 to 5.2 microg/kg. PCBs were found in 20-90% of samples, showing concentrations between 2.3 and 17.3 microg/kg.

Chromatography, Gas↗

Rotator interval closure after arthroscopic capsulolabral repair: a technical variation.

Rotator interval tear is one of the lesions identified in patients with glenohumeral instability. We present our technique for arthroscopic interval capsule repair. After having performed Bankart reconstruction, we pull the anterosuperior cannula back some millimeters and introduce a Penetrator suture retriever forceps (Arthrex, Naples, FL) through the upper interval capsule into the joint. Then we also remove some millimeters of the anterior cannula and introduce a suture passer (Spectrum; Linvatec, Largo, FL) loaded with a monofilament suture through the lower interval capsule. The suture is pushed into the joint and, using the Penetrator suture retriever forceps, we retrieve it out of the joint. This suture is replaced if desired by a permanent braided suture. Next, a suture passer (Arthrex) advances the end of the suture from the anterosuperior portal into the joint. The suture is retrieved out of the joint from the anterior cannula with a crochet hook. We tie the suture down the anterior cannula to close the anterior capsule. Because we use cannulas, we can use a sliding knot. The degree of tightening can be observed directly under arthroscopic view but the knot is outside of the capsule. We believe that this method is easy, effective, and reproducible.

Arthroscopy↗

High prevalence of multiple resistance to antibiotics in Salmonella serovars isolated from a poultry slaughterhouse in Spain.

Salmonellosis is a major foodborne infection in Spain, and strains that are resistant to a great variety of antibiotics have become a major public health concern. The aim of this study was to determine the level of antibiotic resistance in 133 Salmonella isolates obtained from a poultry slaughterhouse in Zaragoza (NE Spain). Antimicrobial resistance testing was performed by disk diffusion method using 19 antibiotics. Results were interpreted following the NCCLS criteria. Overall, the highest percentage of resistance was found to the following antimicrobial agents: sulfadiazine (96.2%), neomycin (53.4%), tetracycline (21.8%), and streptomycin (11.3%). All isolates were found to be resistant to one or more of the antibiotics tested. Multiple resistance was observed in 87 strains (65.4%). We found 23 different patterns of resistance in Salmonella Enteritidis. Resistance to sulfadiazine was the most common single resistance. The most frequent patterns of multiresistant strains were neomycin+sulfadiazine and neomycin+tetracycline+sulfadiazine. S. 4,5,12:b: showed the highest percentages of resistance to the tested drugs, with five different resistance patterns found. Ampicillin+chloramphenicol+streptomycin+sulphonamides+tetracycline (ACSSuT) resistance pattern, commonly associated with S. Typhimurium DT 104, was not detected in strains of the same phage type from broilers. The appearance of substantial multiresistance in foodborne Salmonella isolates suggests the need for more prudent use of antibiotics by farmers, veterinarians, and physicians.

Abattoirs↗

Multinational survey of osteoporotic fracture management.

Osteoporosis is characterized by a decreased bone mass and an increased bone fragility and susceptibility to fracture. Patients with a fragility fracture at any site have an increased risk of sustaining future fractures. Orthopedic surgeons manage most of these fractures and are often the only physician seen by the patient. Mounting evidence that orthopedic surgeons are not well attuned to osteoporosis led the Bone and Joint Decade (BJD) and the International Osteoporosis Foundation (IOF) to survey 3,422 orthopedic surgeons in France, Germany, Italy, Spain, the United Kingdom, and New Zealand. The majority of the respondents in all countries had the opinion that the orthopedic surgeon should identify and initiate the assessment of osteoporosis in patients with fragility fractures. Heterogeneous practice pattern exist in different countries; however, identification and treatment of the osteoporotic patient seems to be insufficient in many areas: half of the orthopedic surgeons surveyed received little or no training in osteoporosis. Only approximately one in four orthopedic surgeons in France, the UK and New Zealand regarded themselves as knowledgeable about treatment modalities. Less than one-fifth of the orthopedic surgeons arranged for a surgically treated patient with a fragility fracture to have a bone mineral density (BMD) test. Twenty percent said that they never refer a patient after a fragility fracture for BMD. Only half of the orthopedic surgeons in southern Europe know about the importance of some external risk factors for hip fractures (cataracts, poor lighting, pathway obstacles, poor balance). In summary, this survey clearly indicates that many orthopedic surgeons still neglect to identify, assess and treat patients with fragility fractures for osteoporosis. More educational opportunities need to be offered to orthopedic surgeons through articles, web-based learning and educational seminars. Development of a simple clinical pathway from evidence-based guidelines is an important step to ensure that optimal care is provided for patients with fragility fractures.

Attitude of Health Personnel↗

Marchetti nailing of humeral shaft delayed unions.

The purpose of this study is to present the results of Marchetti nailing in humeral shaft delayed unions. Fifteen humeral shaft delayed unions were treated with the Marchetti nail. The average age of patients was 52.3 years. All had been treated initially by conservative methods. Delay from trauma to surgery averaged 4.8 months. The nailing technique was retrograde, and reaming of the fracture focus was always performed. Bone graft was not added. Thirteen patients achieved union, in an average of 3.3 months. Two patients require further surgery to gain union. Shoulder and elbow motion was excellent in 10 patients, moderate in four and poor in one. The functional result was excellent in nine patients, good in two, fair in two, and poor in two. Marchetti nailing seems to be an acceptable alternative for humeral shaft delayed unions.

Adult↗