Factores de riesgo asociados a infección periprotésica en el paciente con fractura del cuello femoral: estudio de casos y controles / Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study

Antecedentes y objetivo: La infección es una de las complicaciones locales más importantes en el paciente con fractura del cuello femoral tratada con una artroplastia. El objetivo del presente estudio es describir y analizar posibles factores de riesgo que podrían estar implicados en la infección periprotésica del paciente con fractura del cuello femoral. Material y métodos: Se realizó un estudio de casos y controles retrospectivo que incluye a pacientes con fractura del cuello femoral tratada con una artroplastia en el periodo comprendido entre enero de 2015 y diciembre de 2017. Se definieron como casos a los pacientes con fractura del cuello femoral que tras someterse a una artroplastia (hemiartroplastia o artroplastia total de cadera) tuvieron como desenlace una infección periprotésica, cuyo diagnóstico se llevó a cabo atendiendo a los criterios mayores y menores descritos en el Consenso Internacional de Infecciones Musculoesqueléticas (Philadelphia 2018). Con la intención de atenuar la influencia de variables que podrían considerarse confusoras, se realizó un análisis multivariante. Resultados: Se apreció una asociación estadísticamente significativa entre infección periprotésica y determinadas variables presentes en el momento del ingreso, entre las que se encuentran la presencia de anemia moderada o severa (OR: 10,91; IC95%: 1,07-111,50; p=0,007), trombocitopenia (OR: 27,72; IC95%: 3,48-221,01; p=0,002), el antecedente tromboembólico (OR: 8,80; IC95%: 1,31-59,38; p=0,026), el trastorno ansioso-depresivo en tratamiento con 2 o 3 fármacos (OR: 21,36; IC95%: 3,65-125,12; p=0,001) y la hepatopatía (OR: 32,04; IC95%: 2,59-396,29; p=0,007). Conclusiones: La infección periprotésica en el paciente con fractura del cuello femoral tratado con una artroplastia podría relacionarse con la presencia de determinadas variables en el momento del ingreso hospitalario, entre las que se encuentran la anemia moderada o severa...(AU)

Background: Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture. Methods: A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out. Outcomes: A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95%CI: 1.07-111.50; P=.007), thrombocytopenia (OR: 27.72; 95%CI: 3.48-221.01; P=.002), history of thromboembolism event (OR: 8.80; 95%CI: 1.31-59.38; P=.026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95%CI: 3.65-125.12; P=.001) and liver disease (OR: 32.04; 95%CI: 2.59-396.29; P=.007). Conclusions: Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.(AU)

[Translated article] Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case–control study / Factores de riesgo asociados a infección periprotésica en el paciente con fractura del cuello femoral: estudio de casos y controles

Antecedentes y objetivo: La infección es una de las complicaciones locales más importantes en el paciente con fractura del cuello femoral tratada con una artroplastia. El objetivo del presente estudio es describir y analizar posibles factores de riesgo que podrían estar implicados en la infección periprotésica del paciente con fractura del cuello femoral. Material y métodos: Se realizó un estudio de casos y controles retrospectivo que incluye a pacientes con fractura del cuello femoral tratada con una artroplastia en el periodo comprendido entre enero de 2015 y diciembre de 2017. Se definieron como casos a los pacientes con fractura del cuello femoral que tras someterse a una artroplastia (hemiartroplastia o artroplastia total de cadera) tuvieron como desenlace una infección periprotésica, cuyo diagnóstico se llevó a cabo atendiendo a los criterios mayores y menores descritos en el Consenso Internacional de Infecciones Musculoesqueléticas (Philadelphia 2018). Con la intención de atenuar la influencia de variables que podrían considerarse confusoras, se realizó un análisis multivariante. Resultados: Se apreció una asociación estadísticamente significativa entre infección periprotésica y determinadas variables presentes en el momento del ingreso, entre las que se encuentran la presencia de anemia moderada o severa (OR: 10,91; IC95%: 1,07-111,50; p=0,007), trombocitopenia (OR: 27,72; IC95%: 3,48-221,01; p=0,002), el antecedente tromboembólico (OR: 8,80; IC95%: 1,31-59,38; p=0,026), el trastorno ansioso-depresivo en tratamiento con 2 o 3 fármacos (OR: 21,36; IC95%: 3,65-125,12; p=0,001) y la hepatopatía (OR: 32,04; IC95%: 2,59-396,29; p=0,007). Conclusiones: La infección periprotésica en el paciente con fractura del cuello femoral tratado con una artroplastia podría relacionarse con la presencia de determinadas variables en el momento del ingreso hospitalario, entre las que se encuentran la anemia moderada o severa...(AU)

Background: Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture. Methods: A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out. Outcomes: A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95%CI: 1.07-111.50; P=.007), thrombocytopenia (OR: 27.72; 95%CI: 3.48-221.01; P=.002), history of thromboembolism event (OR: 8.80; 95%CI: 1.31-59.38; P=.026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95%CI: 3.65-125.12; P=.001) and liver disease (OR: 32.04; 95%CI: 2.59-396.29; P=.007). Conclusions: Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.(AU)

Validez clínica de la histología intraoperatoria en el diagnóstico de la infección protésica / Clinical validity of the intraoperative histology in the diagnosis of prosthetic joint infection

Antecedentes y objetivo: Diferentes autores han puesto de manifiesto la utilidad del análisis histológico en el diagnóstico de la infección protésica; sin embargo, todavía hoy, su validez clínica es motivo de controversia. El objetivo del presente manuscrito es describir y analizar la validez clínica del análisis histológico en el diagnóstico de infección protésica en el paciente sometido a un recambio protésico de cadera o rodilla. Material y métodos: Se presenta un estudio retrospectivo que incluye 133 recambios protésicos de cadera y rodilla realizados en nuestro centro entre 2008 y 2020. Se realizó un análisis estadístico descriptivo, bivariado y se determinó la validez clínica del análisis histológico. Resultados: La validez clínica del análisis histológico ofreció una sensibilidad del 48%, una especificidad del 91%, un valor predictivo positivo del 55% y un valor predictivo negativo del 88%. Conclusiones: La determinación de la validez clínica del análisis histológico pone de manifiesto una especificidad elevada. Dicho análisis supone una herramienta diagnóstica apropiada para detectar pacientes sanos, con ausencia de infección.(AU)

Background and aim: Different authors have demonstrated the usefulness of the histological analysis in the diagnosis of prosthetic joint infection; however, its clinical validity is still controversial. The aim of this article is to describe and analyze the clinical validity of histological analysis in the diagnosis of prosthetic infection in patients undergoing hip or knee prosthetic replacement. Material and methods: We present a retrospective study including 133 hip and knee prosthetic replacements performed in our center between 2008 and 2020. A descriptive, bivariate statistical analysis was performed and the clinical validity of the histological analysis was determined. Outcomes: The clinical validity of the intraoperative histology offered a sensitivity of 48%, a specificity of 91%, a positive predictive value of 55% and a negative predictive value of 88%. Conclusions: The determination of the clinical validity of histological analysis shows a high specificity. This analysis is an appropriate diagnostic tool for detecting healthy patients, with no infection.(AU)

[Translated article] Clinical validity of the intraoperative histology in the diagnosis of prosthetic joint infection / Validez clínica de la histología intraoperatoria en el diagnóstico de la infección protésica

Background and aim: Different authors have demonstrated the usefulness of the histological analysis in the diagnosis of prosthetic joint infection; however, its clinical validity is still controversial. The aim of this article is to describe and analyze the clinical validity of histological analysis in the diagnosis of prosthetic infection in patients undergoing hip or knee prosthetic replacement. Material and methods: We present a retrospective study including 133 hip and knee prosthetic replacements performed in our center between 2008 and 2020. A descriptive, bivariate statistical analysis was performed and the clinical validity of the histological analysis was determined. Outcomes: The clinical validity of the intraoperative histology offered a sensitivity of 48%, a specificity of 91%, a positive predictive value of 55% and a negative predictive value of 88%. Conclusions: The determination of the clinical validity of histological analysis shows a high specificity. This analysis is an appropriate diagnostic tool for detecting healthy patients, with no infection.(AU)

Antecedentes y objetivo: Diferentes autores han puesto de manifiesto la utilidad del análisis histológico en el diagnóstico de la infección protésica; sin embargo, todavía hoy, su validez clínica es motivo de controversia. El objetivo del presente manuscrito es describir y analizar la validez clínica del análisis histológico en el diagnóstico de infección protésica en el paciente sometido a un recambio protésico de cadera o rodilla. Material y métodos: Se presenta un estudio retrospectivo que incluye 133 recambios protésicos de cadera y rodilla realizados en nuestro centro entre 2008 y 2020. Se realizó un análisis estadístico descriptivo, bivariado y se determinó la validez clínica del análisis histológico. Resultados: La validez clínica del análisis histológico ofreció una sensibilidad del 48%, una especificidad del 91%, un valor predictivo positivo del 55% y un valor predictivo negativo del 88%. Conclusiones: La determinación de la validez clínica del análisis histológico pone de manifiesto una especificidad elevada. Dicho análisis supone una herramienta diagnóstica apropiada para detectar pacientes sanos, con ausencia de infección.(AU)

[Translated article] Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study.

BACKGROUND: Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture. METHODS: A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out. OUTCOMES: A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95% CI: 1.07-111.50; P = .007), thrombocytopenia (OR: 27.72;95% CI: 3.48-221.01; P = .002), history of thromboembolism event (OR: 8.80; 95% CI: 1.31-59.38; P = .026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95% CI: 3.65-125.12; P = .001) and liver disease (OR: 32.04; 95% CI: 2.59-396.29; P = .007). CONCLUSIONS: Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study. / Factores de riesgo asociados a infección periprotésica en el paciente con fractura del cuello femoral: estudio de casos y controles.

BACKGROUND: Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture. METHODS: A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out. OUTCOMES: A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95%CI: 1.07-111.50; P=.007), thrombocytopenia (OR: 27.72; 95%CI: 3.48-221.01; P=.002), history of thromboembolism event (OR: 8.80; 95%CI: 1.31-59.38; P=.026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95%CI: 3.65-125.12; P=.001) and liver disease (OR: 32.04; 95%CI: 2.59-396.29; P=.007). CONCLUSIONS: Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

Clinical validity of the intraoperative histology in the diagnosis of prosthetic joint infection. / Validez clínica de la histología intraoperatoria en el diagnóstico de la infección protésica.

BACKGROUND AND AIM: Different authors have demonstrated the usefulness of the histological analysis in the diagnosis of prosthetic joint infection; however, its clinical validity is still controversial. The aim of this article is to describe and analyze the clinical validity of histological analysis in the diagnosis of prosthetic infection in patients undergoing hip or knee prosthetic replacement. MATERIAL AND METHODS: We present a retrospective study including 133 hip and knee prosthetic replacements performed in our center between 2008 and 2020. A descriptive, bivariate statistical analysis was performed and the clinical validity of the histological analysis was determined. OUTCOMES: The clinical validity of the intraoperative histology offered a sensitivity of 48%, a specificity of 91%, a positive predictive value of 55% and a negative predictive value of 88%. CONCLUSIONS: The determination of the clinical validity of histological analysis shows a high specificity. This analysis is an appropriate diagnostic tool for detecting healthy patients, with no infection.

[Translated article] Clinical validity of the intraoperative histology in the diagnosis of prosthetic joint infection.

BACKGROUND AND AIM: Different authors have demonstrated the usefulness of the histological analysis in the diagnosis of prosthetic joint infection; however, its clinical validity is still controversial. The aim of this article is to describe and analyse the clinical validity of histological analysis in the diagnosis of prosthetic infection in patients undergoing hip or knee prosthetic replacement. MATERIAL AND METHODS: We present a retrospective study including 133 hip and knee prosthetic replacements performed in our centre between 2008 and 2020. A descriptive, bivariate statistical analysis was performed and the clinical validity of the histological analysis was determined. OUTCOMES: The clinical validity of the intraoperative histology offered a sensitivity of 48%, a specificity of 91%, a positive predictive value of 55% and a negative predictive value of 88%. CONCLUSIONS: The determination of the clinical validity of histological analysis shows a high specificity. This analysis is an appropriate diagnostic tool for detecting healthy patients, with no infection.

[Influence of medical outliers in patients with femoral neck fracture]. / Influencia del ingreso hospitalario ectópico en pacientes con fractura del cuello femoral.

OBJECTIVES: The objective is to describe and analyze how outlier admission influences hospital stay and the appearance of complications in patients with a femoral neck fracture treated with arthroplasty. MATERIAL AND METHOD: A historical cohort study was carried out in which the group of patients with a displaced fracture of the femoral neck who had an outlier admission was defined as an exposed cohort, that is, they were admitted to a hospitalization area not belonging to the Orthopedic Surgery and Traumatology department, unlike the unexposed cohort, that included patients admitted to a hospitalization area assigned to the Orthopedic Surgery and Traumatology department. RESULTS: Outlier admission was a risk factor for requiring a postoperative transfusion (RR 1.52, 95% CI 1.05-2.21; P=.035), to have a postoperative stay longer than 5 days (RR 1.35, 95% CI 1.04-1.74; P=.038) and to suffer general postoperative complications (RR 1.35, 95% CI 1.02-1.78; P=.048). CONCLUSIONS: Outlier admission is a threat to the quality and safety of health care. In patients over 80 years of age, medical outliers is a risk factor for postoperative transfusion and systemic postoperative complications.

Result of the implementation of telematic consultations in orthopaedic surgery and traumatology during COVID-19 laparoscopic surgery. / Resultado de la implantación de consultas telemáticas en cirugía ortopédica y traumatología durante la pandemia COVID-19.

The COVID pandemic has made telematic consultations a basic tool in daily practice. AIMS: The main objective of the study is to assess the results of the application of telematic consultations to limit the mobility of patients. The operational objectives are; to propose a consultation plan, to know how attendance limits consultations and to define which pathologies benefit the most from this plan. METHODS: A scheme is proposed with the creation of pre-scheduled clinic to assess suitability and the possibility of carrying them out in a single non face-to-face act. RESULTS: Phone call to 5,619 patients were made with a lack of response of 19%. The cases of 74% of the patients that answered were resolved virtually. There is a difference between units, obtaining a higher answering rate from patients appointed to specific clinic units, OR = 0.60, or to general trauma ones, OR = 0.67. The lowest answering rate was obtained from those derived from the emergency department. Twenty per cent of the consultations were not accompanied by complementary tests that would have favored the resolution in a single act. The general trauma consultations, OR = 0.34, postoperative control, OR = 0.49, and specific unit ones, OR = 0.40, were the ones that better met this requirement. Out of the remaining patients, the general trauma consultations, OR = 0.50, and those referred to units, OR = 0.54, were the ones that had a higher resolution rate without in- person consultation. CONCLUSIONS: The cases of 74% of the patients who answered the phone call were resolved virtually. Cases of 20% of the patients cannot be solved in a single act because they are derived without complementary tests. Osteosynthesis and postoperative arthroscopic follow-up consultations are the ones that need to be carried out in person the most.

A prospective cohort study on the effects of RME in the mandibular dentition of cleft subjects.

PURPOSE: Rapid maxillary expansion (RME) is the most frequent orthopedic procedure in cleft subjects. However, little is known about its effects on the mandible. The aim of this study was to investigate the spontaneous response of the mandibular teeth following RME. METHODS: This prospective cohort study was carried out with a sample of thirty participants with unilateral cleft lip and palate (UCLP), 8-15 years old, who had transverse maxillary deficiency. Two participants were excluded. They were allocated into three groups: G1 (n = 10), G2 (n = 10), and G3 (n = 8). G1 was treated with a Fan-type expander; G2 with an iMini expander; and G3 with a Hyrax expander. Measurements were performed in Cone Beam CT scans obtained before treatment (T1) and 3 months post-expansion (T2). The primary outcomes were buccolingual inclination of mandibular first molars and canines, and intercanine and intermolar width at different levels. RESULTS: Dental changes were significant (P < 0.05) for intercanine width, increasing in G1 and G2, and for intermolar width, increasing in G2 and G3. There were no significant differences among groups (P > 0.05). CONCLUSION: RME in UCLP subjects performed with these expanders may lead to significant spontaneous changes in both anterior and posterior region of the mandible.

The Kidney, Liver, Index surgery and C reactive protein score is a predictor of treatment response in acute prosthetic joint infection.

PURPOSE: This work seeks to verify the utility of the KLIC score as a predictor of treatment success or failure in patients with knee and hip acute prosthetic joint infections (APJI). These patients were treated in our centre, which is not a prosthetic joint infection reference centre. The KLIC score assesses factors such as chronic kidney failure (2 points) (Kidney), liver disease (1.5 points) (Liver), revision surgery or femoral neck fracture (1.5 points)and cemented prosthesis (2 points) (Index surgery) and a C-reactive protein level (CRP) greater than 11.5 mg/dL (2.5 points), as a predictor of treatment success or failure in patients with knee and hip acute prosthetic joint infections (APJI). METHODS: We retrospectively reviewed 30 patients with APJI who were treated using debridement, antibiotics, irrigation and retention (DAIR) treatment between January 2007 and December 2016. Patients' KLIC scores were calculated. The main outcome was success or failure of DAIR treatment of APJI. RESULTS: DAIR treatment succeeded in 21 cases and failed in nine cases. Differences in outcome were found according to the KLIC score. For KLIC scores >2 and ≤4, there were three successes and zero failures; for scores 4-5, there were nine successes and two failures; for scores >5 and ≤7,there were nine successes and four failures; and for scores >7, there were zero successes and three failures (p = 0.025). We found a positive predictive value and negative predictive value of 33% and 100% for scores ≤4 (score for calculations: 3.5), 43% and 84% for scores 4-5 (4.5), 50% and 68% for scores >5 and ≤7 (5.5), and 100% and 76% for scores >7 (7.5), respectively. The area under the ROC curve was 0.762 (95% confidence interval, 0.569-0.955). CONCLUSIONS: The KLIC score was useful in predicting success or failure of DAIR treatment of APJI. This supports the conclusion that with a score < 3.5, treatment is likely to succeed and with a score of >6, it is likely to fail.

Correction to: The Kidney, Liver, Index surgery and C reactive protein score is a predictor of treatment response in acute prosthetic joint infection.

There is an error in the name of one of the author in the original publication. The correct name is I Rodríguez-Delourme and not Delourne.

Synthesis of a heterogeneous artificial metallolipase with chimeric catalytic activity.

A solid-phase strategy using lipase as a biomolecular scaffold to produce a large amount of Cu(2+)-metalloenzyme is proposed here. The application of this protocol on different 3D cavities of the enzyme allows creating a heterogeneous artificial metallolipase showing chimeric catalytic activity. The artificial catalyst was assessed in Diels-Alder cycloaddition reactions and cascade reactions showing excellent catalytic properties.

Three-dimensional pharyngeal airway changes in orthodontic patients treated with and without extractions.

OBJECTIVE: To evaluate and compare three-dimensional pharyngeal airway changes in orthodontic patients treated with and without extractions. MATERIAL AND METHODS: Pharyngeal airway was analyzed for 31 subjects (15 males, 16 females) treated with extractions of four first premolars and 31 age- and gender-matched controls (15 males, 16 females) treated without extractions. The mean age of subjects was 12.97 ± 1.15 years at the beginning and 15.69 ± 1.28 years at the end of treatment. The mean age of controls was 12.86 ± 0.74 years at the beginning and 15.18 ± 0.86 years at the end of treatment. Nasopharyngeal (NP) and oropharyngeal (OP) volumes, area of maximum pharyngeal constriction (AMPC), and upper arch perimeter were measured on T0 and T1 cone beam computed tomography (CBCT) scans. Paired samples t-test was used for analyzing statistical significance of changes (p ≤ 0.05). RESULTS: There were no statistically significant differences in the pharyngeal airway values between the extraction and non-extraction groups at neither T0 nor T1. The extraction group showed a statistically significant increase for NP and OP volumes and AMPC values. Such increase was also noted in the non-extraction group, without statistical significance for AMPC values. CONCLUSIONS: The findings suggest that an extraction or non-extraction choice for orthodontic treatment would not affect the pharyngeal airway.

Effect of alternative temozolomide schedules on glioblastoma O(6)-methylguanine-DNA methyltransferase activity and survival.

BACKGROUND: O(6)-methylguanine-DNA methyltransferase (MGMT) expression in glioblastoma correlates with temozolomide resistance. Dose-intense temozolomide schedules deplete MGMT activity in peripheral blood mononuclear cells; however, no published data exist evaluating the effect of temozolomide schedules on intracranial tumour MGMT activity. METHODS: Human glioblastoma cells (GBM43) with an unmethylated MGMT promoter were implanted intracranially in immunodeficient rodents. Three weeks later, animals received temozolomide 200 mg m(-2) for 5 days (schedule A, standard dose) or 100 mg m(-2) for 21 days (schedule B, dose intense). RESULTS: Tumour MGMT activity was depleted by day 6 in both treatment groups compared with baseline. O(6)-methylguanine-DNA methyltransferase activity returned to baseline by day 22 in the schedule A group, but remained suppressed in the schedule B group. By day 29, MGMT activity had returned to baseline in both groups. Mean tumour volume was significantly decreased compared with untreated controls with either schedule (P<0.01), although neither schedule was superior (P=0.60). Median survival was 64, 42, and 28 days for schedule A, schedule B, and no drug, respectively (P<0.001 A or B vs control, P=NS A vs B). CONCLUSIONS: Dose-intense temozolomide prolongs tumour MGMT activity depletion compared with standard dosing, however, survival was not improved in this model.

Advances in the design of new epoxy supports for enzyme immobilization-stabilization.

Multipoint covalent immobilization of enzymes (through very short spacer arms) on support surfaces promotes a very interesting 'rigidification' of protein molecules. In this case, the relative positions of each residue of the enzyme involved in the immobilization process have to be preserved unchanged during any conformational change induced on the immobilized enzyme by any distorting agent (heat, organic solvents etc.). In this way, multipoint covalent immobilization should induce a very strong stabilization of immobilized enzymes. Epoxy-activated supports are able to chemically react with all nucleophile groups placed on the protein surface: lysine, histidine, cysteine, tyrosine etc. Besides, epoxy groups are very stable. This allows the performance of very long enzyme-support reactions, enabling us to get very intense multipoint covalent attachment. In this way, these epoxy supports seem to be very suitable to stabilize industrial enzymes by multipoint covalent attachment. However, epoxy groups exhibit a low intermolecular reactivity towards nucleophiles and hence the enzymes are not able to directly react with the epoxy supports. Thus a rapid physical adsorption of enzymes on the supports becomes a first step, followed by an additional rapid 'intramolecular' reaction between the already adsorbed enzyme and the activated support. In this situation, a suitable first orientation of the enzyme on the support (e.g. through regions that are very rich in nucleophiles) is obviously necessary to get a very intense additional multipoint covalent immobilization. The preparation of different 'generations' of epoxy supports and the design of different protocols to fully control the first interaction between enzymes and epoxy supports will be reviewed in this paper. Finally, the possibilities of a directed immobilization of mutated enzymes (change of an amino acid by cysteine on specific points of the protein surface) on tailor-made disulfide-epoxy supports will be discussed as an almost-ideal procedure to achieve very intense and very efficient rigidification of a desired region of industrial enzymes.

Three-dimensional cone beam computerized tomography in orthodontics.

There has been an escalating interest in three-dimensional imaging devices over the last decade. Orthodontists are beginning to appreciate the advantages that the third dimension gives to clinical diagnosis, treatment planning and patient education. This article focuses on the cutting edge technology of cone beam CT, which utilizes conventional X-ray technology and computerized volumetric reconstruction to reproduce a three-dimensional image. A variety of applications and range of issues associated with this technology will be discussed.

Purification, immobilization, and stabilization of a lipase from Bacillus thermocatenulatus by interfacial adsorption on hydrophobic supports.

A lipase from Bacillus thermocatenulatus (BTL2) cloned in E. coli has been purified using a very simple method: interfacial activation on a hydrophobic support followed by desorption with Triton. Only one band was detected by SDS-PAGE. The pure enzyme was immobilized using different methodologies. BTL2 adsorbed on a hydrophobic support (octadecyl-Sepabeads) exhibited a hyperactivation with respect to the soluble enzyme, whereas the other immobilized preparations suffered a slight decrease in the expressed activity. The soluble enzyme was very stable, but all immobilized preparations were much more stable than the soluble enzyme, the octadecyl-Sepabeads-BTL2 preparation being the most stable one in all conditions (high temperature or in the presence of organic cosolvents), maintaining 100% of the activity at 65 degrees C or 30% of dioxane and 45 degrees C after several days of incubation. The glyoxyl preparation, the second more stable, retained 80% of the initial activity after 2 days, respectively. The adsorption of this thermophilic lipase on octadecyl-Sepabeads permitted an increase in the optimal temperature of the enzyme of 10 degrees C.