Impacto de la demencia en la supervivencia de los pacientes con fractura de cadera intervenidos mediante prótesis total y parcial / Impact of dementia on the survival of patients with hip fracture after undergoing total and partial prosthesis

Objetivo: Realizar un análisis de la supervivencia comparativa de los pacientes diagnosticados de fracturas de cadera (FC) en el Servicio Vasco de Salud de 2010 a 2016 en función de que estuviesen o no diagnosticados de demencia y del tipo de artroplastia. Material y métodos: Estudio de tipo observacional (real world data) de supervivencia. Los datos fueron obtenidos de las bases de datos administrativas y clínicas del Servicio Vasco de Salud mediante el gestor Oracle Business Intelligence (OBI). Se analizaron todos los casos de fracturas de cuello de fémur desde el año 2010 al 2016 en Servicio Vasco de Salud. Se realizó un análisis descriptivo para detectar diferencias entre grupos según diagnóstico previo de demencia y tipo de prótesis. Para obtener las curvas de supervivencia se utilizó el método de Kaplan?Meier y su comparación se realizó por parejas mediante el logrank test. Mediante la regresión de Cox se analizó el riesgo de fallecimiento ajustado de cada grupo. Resultados: Se identificaron 5.867 pacientes con FC, siendo 1.131 pacientes sin demencia y prótesis total, 3.073 sin demencia y prótesis parcial, 176 con demencia y prótesis total y 1.487 con demencia y prótesis parcial. La mediana de la supervivencia fue de 9,08 años, 3,79 años, 2,55 años y 2,54 años respectivamente. La comparación de las curvas de supervivencia resultó significativa para todos los casos excepto entre los dos últimos grupos. Utilizando el primer grupo como referencia, el odds ratio de fallecimiento del resto fue 1,56, 2,27 y 2,37 respectivamente. Al analizar el riesgo de fallecimiento únicamente para los pacientes con demencia, el tipo de prótesis no resultó ser estadísticamente significativo. Conclusiones: La demencia influye en la curva de supervivencia de los pacientes que son sometidos a una artroplastia tras una fractura de cuello femoral, teniendo una mortalidad similar los que reciben una artroplastia total que los que se intervienen con una parcial. (AU)

Objetive: To carry out a comparative survival analysis of patients diagnosed with hip fractures (HF) in the Basque Health Service from 2010 to 2016 depending on whether or not they were diagnosed with dementia and the type of arthroplasty. Material and methods: Observational study (real world data) of survival. The data were obtained from the administrative and clinical databases of the Basque Health Service using the Oracle Business Intelligence (OBI) manager. All cases of femur neck fractures from 2010 to 2016 were analyzed in the Basque Health Service. A descriptive analysis was carried out to detect differences between groups according to previous diagnosis of dementia and type of prosthesis. The Kaplan-Meier method was used to obtain the survival curves and their comparison was made in pairs using the Achievement test. The adjusted risk of death for each group was analyzed with the Cox regression model. Results: 5,867 patients with CF were identified, being 1,131 patients without dementia and total prosthesis, 3,073 without dementia and partial prosthesis, 176 with dementia and total prosthesis and 1,487 with dementia and partial prosthesis. The median survival was 9.08 years, 3.79 years, 2.55 years, and 2.54 years respectively. The comparison of the survival curves was significant for all cases except between the last two groups. Using the first group as a reference, the odds ratio of death for the rest was 1.56, 2.27 and 2.37 respectively. When analyzing the risk of death only for patients with dementia, the type of prosthesis was not statistically significant. Conclusions: Dementia influences the survival curve of patients who undergo arthroplasty after a femur neck fracture, with those who undergo a total arthroplasty have a similar mortality rate as those who undergo partial arthroplasty. (AU)

Obturator dislocation of total hip arthroplasty with disassembly of the prosthesis components and periprosthetic fracture in morbid obese patient.

INTRODUCTION: Anterior dislocation is a rare complication of total hip arthroplasty (THA). There exist only three cases in the literature. None of them report disassembly of the prosthesis components. We present a morbidly obese woman who suffered an irreducible obturator dislocation of an infected total hip arthroplasty (THA), due to uncontrolled adduction during an early debridement surgery. Following unsuccessful closed reduction attempts, a Vancouver B2 periprosthetic fracture and disassembly of the prosthetic components were observed. Two-stage revision THA was necessary to resolve the infection and restore hip functionality. In obturator dislocation, the femoral head prosthetic can be trapped in the obturator foramen, and this may disassemble the prosthesis components during reduction maneuvers; theres also risk of periprosthetic fracture. This mandate an open reduction of the joint. Patient obesity could be a determining factor for this rare type of hip arthroplasty dislocation. Obturator dislocation is an extremely rare complication of the total hip arthroplasty, whose reductions should be handled with caution given the risks of periprosthetic fractures. In most cases, an open reduction of the joint is required. CLINICAL IMPORTANCE: Our work is likely to be of great interest because it offers tips for the management of this rare complication based on our experience.

INTRODUCCIÓN: La luxación anterior es una complicación poco frecuente de la artroplastia total de cadera (ATC). Sólo existen tres casos en la literatura. Ninguno de ellos informa del desmontaje de los componentes de la prótesis. Presentamos el caso una mujer obesa que sufrió una luxación irreducible de una artroplastia total de cadera (THA), la cual estaba infectada, debido a la aducción no controlada durante una cirugía de desbridamiento temprano. Después de los intentos fallidos de reducción cerrada, se presentó una fractura periprotésica clasificada como Vancouver B2 y el desmontaje de los componentes protésicos. Ameritó cirugía de revisión en dos etapas, lo cual se realizó para resolver la infección y restaurar la funcionalidad de la cadera. En la luxación obturatriz, la cabeza femoral puede quedar atrapada en el agujero obturador y, como consecuencia, favorecer la disociación de los componentes protésicos al intentar la reducción, asimismo puede favorecer un brazo de palanca que produzca una fractura periprotésica. La obesidad puede ser un factor determinante para la producción de esta rara complicación. Por todo lo anterior, se recomienda considerar de entrada la reducción abierta. La luxación obturatriz es una complicación rara en la artroplastia total de cadera; su tratamiento puede ser difícil y asociarse a fracturas. La relevancia de este caso es que permite mostrar algunas estrategias de manejo para prevenir complicaciones catastróficas.

Usefulness of a national hip fracture registry to evaluate the profile of patients in whom antiosteoporotic treatment is prescribed following hospital discharge.

This study was carried out to describe the profile of prescription of antiosteoporotic treatment at discharge after a hip fracture in the Spanish National Hip Fracture Registry. Prescription rates among hospitals ranged from 0 to 94% of patients discharged. The prescription rate was higher among patients with better cognitive and functional baseline status. PURPOSE: National hip fracture registries are useful for assessing current care processes. The goals of this study were as follows: first, to know the rate of antiosteoporotic prescription at discharge among hip fracture patients in hospitals participating in the Spanish National Hip Fracture Registry (RNFC); second, to compare the differences between treated and non-treated patients; third, to analyze patients' characteristics associated with antiosteoporotic prescription at discharge; and fourth, to evaluate whether there were differences in the profile of patients discharged from hospitals with high and low prescription rates. METHOD: Patients discharged after a fragility hip fracture in 2017 and participating in the RNFC were included. Demographic variables, cognitive and functional status, prefracture osteoporosis treatment, fracture type, anesthetic risk, hospital volume, and antiosteoporotic prescription at discharge were analyzed. Given that patients were clustered within hospitals, intraclass correlation was calculated and generalized estimating equations were fitted. RESULTS: A total of 6701 patients from 54 hospitals were included. Antiosteoporotic prescription at discharge was prescribed to 36.5% (CI95% 35.8-37.2%), with a wide inter-hospital variability (range 0-94%). The intraclass correlation due of clustering of patients within hospitals was 47.9%. Antiosteoporotic prescription was more likely in patients who were younger, lived at home, previously treated for osteoporosis, had better baseline functional and cognitive status, lower anesthetic risk, and were discharged from high-volume hospitals, all with p < 0.001. The general profile of patients discharged from hospitals with high and low rate of prescription was similar. CONCLUSIONS: There is a wide variability between hospitals regarding antiosteoporotic prescription after hip fracture. This is more likely to be initiated in patients with better clinical, functional, and mental status and in those discharged from hospitals with larger volumes of patients. These results offer insights regarding the selection of patients receiving secondary prevention and raises questions on who and how many should be treated.

Obturator dislocation of total hip arthroplasty with disassembly of the prosthesis components and periprosthetic fracture in morbid obese patient / Luxación obturatriz de una prótesis total de cadera con desensamblaje de los componentes y fractura periprotésica en un paciente obeso

Abstract: Introduction: Anterior dislocation is a rare complication of total hip arthroplasty (THA). There exist only three cases in the literature. None of them report disassembly of the prosthesis components. We present a morbidly obese woman who suffered an irreducible obturator dislocation of an infected total hip arthroplasty (THA), due to uncontrolled adduction during an early debridement surgery. Following unsuccessful closed reduction attempts, a Vancouver B2 periprosthetic fracture and disassembly of the prosthetic components were observed. Two-stage revision THA was necessary to resolve the infection and restore hip functionality. In obturator dislocation, the femoral head prosthetic can be trapped in the obturator foramen, and this may disassemble the prosthesis components during reduction maneuvers; there's also risk of periprosthetic fracture. This mandate an open reduction of the joint. Patient obesity could be a determining factor for this rare type of hip arthroplasty dislocation. Obturator dislocation is an extremely rare complication of the total hip arthroplasty, whose reductions should be handled with caution given the risks of periprosthetic fractures. In most cases, an open reduction of the joint is required. Clinical importance: Our work is likely to be of great interest because it offers tips for the management of this rare complication based on our experience.

Resumen: Introducción: La luxación anterior es una complicación poco frecuente de la artroplastia total de cadera (ATC). Sólo existen tres casos en la literatura. Ninguno de ellos informa del desmontaje de los componentes de la prótesis. Presentamos el caso una mujer obesa que sufrió una luxación irreducible de una artroplastia total de cadera (THA), la cual estaba infectada, debido a la aducción no controlada durante una cirugía de desbridamiento temprano. Después de los intentos fallidos de reducción cerrada, se presentó una fractura periprotésica clasificada como Vancouver B2 y el desmontaje de los componentes protésicos. Ameritó cirugía de revisión en dos etapas, lo cual se realizó para resolver la infección y restaurar la funcionalidad de la cadera. En la luxación obturatriz, la cabeza femoral puede quedar atrapada en el agujero obturador y, como consecuencia, favorecer la disociación de los componentes protésicos al intentar la reducción, asimismo puede favorecer un brazo de palanca que produzca una fractura periprotésica. La obesidad puede ser un factor determinante para la producción de esta rara complicación. Por todo lo anterior, se recomienda considerar de entrada la reducción abierta. La luxación obturatriz es una complicación rara en la artroplastia total de cadera; su tratamiento puede ser difícil y asociarse a fracturas. La relevancia de este caso es que permite mostrar algunas estrategias de manejo para prevenir complicaciones catastróficas.

Spanish National Hip Fracture Registry (RNFC): analysis of its first annual report and international comparison with other established registries.

Hip fracture registries have helped improve quality of care and reduce variability, and several audits exist worldwide. The results of the Spanish National Hip Fracture Registry are presented and compared with 13 other national registries, highlighting similarities and differences to define areas of improvement, particularly surgical delay and early mobilization. INTRODUCTION: Hip fracture audits have been useful for monitoring current practice and defining areas in need of improvement. Most established registries are from Northern Europe. We present the results from the first annual report of the Spanish Hip Fracture Registry (RNFC) and compare them with other publically available audit reports. METHOD: Comparison of the results from Spain with the most recent reports from another ten established hip fracture registries highlights the differences in audit characteristics, casemix, management, and outcomes. RESULTS: Of the patients treated in 54 hospitals, 7.208 were included in the registry between January and October 2017. Compared with other registries, the RNFC included patients ≥ 75 years old; in general, they were older, more likely to be female, had a worse prefracture ambulation status, and were more likely to have extracapsular fractures. A larger proportion was treated with intramedullary nails than in other countries, and spinal anesthesia was most commonly used. With a mean of 75.7 h, Spain had by far the longest surgical delay, and the lowest proportion of patients mobilized on the first postoperative day (58.5%). Consequently, development of pressure ulcers was high, but length of stay, mortality, and discharge to home remained in the range of other audits. CONCLUSIONS: National hip fracture registries have proved effective in changing clinical practice and our understanding of patients with this condition. Such registries tend to be based on an internationally recognized common dataset which would make comparisons between national registries possible, but variations such as age inclusion criteria and follow-up are becoming evident across the world. This variation should be avoided if we are to maximize the comparability of registry results and help different countries learn from each other's practice. The results reported in the Spanish RNFC, compared with those of other countries, highlight the differences between countries and detect areas of improvement, particularly surgical delay and early mobilization.

Spanish National Hip Fracture Registry (SNHFR): a description of its objectives, methodology and implementation / Registro Nacional Español de Fracturas de Cadera (RNFC): descripción de sus objetivos, metodología e implementación

Objective: To ascertain the current situation and clinical variability of the provision of care for Hip Fracture (HF) in Spain and the factors related to it by using a National Registry (NHFR) with high patient numbers and territorial representation NHFR, and to compare results on a national and international level and propose standards and criteria to improve healthcare quality. Design: Continuous registry for at least three years of a representative sample of patients admitted to Spanish hospitals due to HF using the Minimum Common Dataset - international Fragility Fracture Network (FFN) MCD, adapted for Spanish. Study scope and subjects: all patients over the age of 74 years who are hospitalized with a diagnosis of a fragility HF at the participating hospitals distributed throughout the Spanish territory. Initially 48 hospitals are included, and we expect to incorporate the highest number of sites possible. Results: It is expected to ascertain the current situation of provision of care for HF in Spain. Each hospital will be offered information regarding their results and their situation compared to the rest. The results from national hospitals will be compared to others included in the registry and to hospitals abroad, which use the same database. Variability will be studied, care standards will be established, and objectives will be proposed for the continuous improvement of the care process of this condition

Objetivo: Conocer la situación actual y la variabilidad clínica del proceso asistencial a la Fractura de Cadera (FC) en España y los factores relacionados con la misma mediante la utilización de un Registro Nacional (RNFC) con elevada casuística y representación territorial RNFC, así como comparar resultados en el ámbito nacional e internacional y proponer estándares y criterios para mejorar la calidad asistencial. Diseño: Registro continuo durante al menos tres años de una muestra representativa de los pacientes ingresados por FC en los hospitales españoles mediante el Minimum Common Dataset - MCD internacional de la Fragility Fracture Network (FFN) adaptado al castellano. Ámbito y sujetos del estudio: se incluirán todos los pacientes mayores de 74 años hospitalizados con el diagnóstico de FC por fragilidad en los hospitales participantes repartidos por el territorio español. Inicialmente están incluidos 48 hospitales, a los que se espera que se vayan incorporando el mayor número posible de centros. Resultados: Se pretende conocer la situación actual de la atención a este proceso en España Se ofrecerá a cada hospital la información de sus resultados y su situación en relación al resto, se compararán los resultados de los hospitales nacionales entre sí y con los hospitales extranjeros incluidos en registros que usan la misma base de datos. Se estudiará la variabilidad, se establecerán estándares asistenciales y se plantearán objetivos para la mejora continua del proceso en la atención a esta patología

Spanish National Hip Fracture Registry (SNHFR): a description of its objectives, methodology and implementation.

OBJECTIVE: To ascertain the current situation and clinical variability of the provision of care for Hip Fracture (HF) in Spain and the factors related to it by using a National Registry (NHFR) with high patient numbers and territorial representation NHFR, and to compare results on a national and international level and propose standards and criteria to improve healthcare quality. DESIGN: Continuous registry for at least three years of a representative sample of patients admitted to Spanish hospitals due to HF using the Minimum Common Dataset - international Fragility Fracture Network (FFN) MCD, adapted for Spanish. STUDY SCOPE AND SUBJECTS: all patients over the age of 74 years who are hospitalized with a diagnosis of a fragility HF at the participating hospitals distributed throughout the Spanish territory. Initially 48 hospitals are included, and we expect to incorporate the highest number of sites possible. RESULTS: It is expected to ascertain the current situation of provision of care for HF in Spain. Each hospital will be offered information regarding their results and their situation compared to the rest. The results from national hospitals will be compared to others included in the registry and to hospitals abroad, which use the same database. Variability will be studied, care standards will be established, and objectives will be proposed for the continuous improvement of the care process of this condition.

[Harlequin ichthyosis--medical and psychosocial challenges]. / Ichthyosis congenita gravis--eine medizinische und psychosoziale Herausforderung.

Harlequin ichthyosis is the most severe congenital keratinizing disorder. It is caused by mutations in the ABCA12 gene leading to defective lipid transport. The infants are born with ectropion, eclabium and fissured plate-like skin. Today these infants can survive with neonatal intensive care and retinoid therapy and need long-term interdisciplinary treatment in order to improve quality of life. However, the outcome in our case is impaired by severe psychomotor developmental delay, which has not yet been associated with Harlequin Ichthyosis.

Content-based access to oral and maxillofacial radiographs.

OBJECTIVES: Content-based access (CBA) to medical image archives, i.e. data retrieval by means of image-based numerical features computed automatically, has capabilities to improve diagnostics, research and education. In this study, the applicability of CBA methods in dentomaxillofacial radiology is evaluated. METHODS: Recent research has discovered numerical features that were successfully applied for an automatic categorization of radiographs. In our experiments, oral and maxillofacial radiographs were obtained from the day-to-day routine of a university hospital and labelled by an experienced dental radiologist regarding the technique and direction of imaging, as well as the displayed anatomy and biosystem. In total, 2000 radiographs of 71 classes with at least 10 samples per class were analysed. A combination of co-occurrence-based texture features and correlation-based similarity measures was used in leaving-one-out experiments for automatic classification. The impact of automatic detection and separation of multi-field images and automatic separability of biosystems were analysed. RESULTS: Automatic categorization yielded error rates of 23.20%, 7.95% and 4.40% with respect to a correct match within the first, fifth and tenth best returns. These figures improved to 23.05%, 7.00%, 4.20%, and 20.05%, 5.65% and 3.25% if automatic decomposition was applied and the classifier was optimized to the dentomaxillofacial imagery, respectively. The dentulous and implant systems were difficult to distinguish. Experiments on non-dental radiographs (10,000 images of 57 classes) yielded 12.6%, 5.6% and 3.6%. CONCLUSION: Using the same numerical features as in medical radiology, oral and maxillofacial radiographs can be reliably indexed by global texture features for CBA and data mining.

Content-based image retrieval in medical applications.

OBJECTIVES: To develop a general structure for semantic image analysis that is suitable for content-based image retrieval in medical applications and an architecture for its efficient implementation. METHODS: Stepwise content analysis of medical images results in six layers of information modeling incorporating medical expert knowledge (raw data layer, registered data layer, feature layer, scheme layer, object layer, knowledge layer). A reference database with 10,000 images categorized according to the image modality, orientation, body region, and biological system is used. By means of prototypes in each category, identification of objects and their geometrical or temporal relationships are handled in the object and the knowledge layer, respectively. A distributed system designed with only three core elements is implemented: (i) the central database holds program sources, processing scheme descriptions, images, features, and administrative information about the workstation cluster; (ii) the scheduler balances distributed computing; and (iii) the web server provides graphical user interfaces for data entry and retrieval, which can be easily adapted to a variety of applications for content-based image retrieval in medicine. RESULTS: Leaving-one-out experiments were distributed by the scheduler and controlled via corresponding job lists offering transparency regarding the viewpoints of a distributed system and the user. The proposed architecture is suitable for content-based image retrieval in medical applications. It improves current picture archiving and communication systems that still rely on alphanumerical descriptions, which are insufficient for image retrieval of high recall and precision.

Historical and political implications of haemophilia in the Spanish royal family.

The political implications of haemophilia in the marriage of King Alfonso XIII of Spain and Princess Victoria Eugenie Battenberg of England have been reviewed in recent books on history. However, the fact that they had haemophilic sons also affected their personal relationship. In this article, we review the consequences haemophilia bore on their lives. We feel great compassion for families who suffer the illness, be it ordinary people or members of royalty; however, in this case, it can be said that when the disease affected a royal couple, the political consequences were great.

A supercritical fluid-based coating technology 1: process considerations.

A novel solvent-free particle coating process, based on the solvent properties of supercritical fluids (SCF) is described. It consists of dissolving one or more coating materials in supercritical CO(2) and then adjusting T/P conditions in the autoclave so that the coating material becomes insoluble in the CO(2). This insolubilization step causes a coating to deposit on the surface of suspended particles. This process has been applied to bovine serum albumin and sugar granules. Coating was effective, but different morphologies were obtained depending on the coating material used. A discontinuous coating has been made using trimyristin, since this material precipitates as micro-needles. Conversely, a smooth, regular coating has been obtained with a commercially available mixture of glycerides and glyceride esters of PEG (Gelucire 50/02) acting like a film-forming agent.

A supercritical fluid-based coating technology. 2: solubility considerations.

Solubility measurements of candidate coating materials have been performed in supercritical (SC) CO(2) so as to select appropriate coating materials for implementation of a solvent-free coating process previously described. Solubility of lipidic compounds such as waxes (paraffin, beeswax, Carnauba wax), pure triglycerides (tricaprin, trimyristin, tripalmitin, tristearin) and mixture of glycerides and fatty acid esters (Gelucire) in SC CO(2) were evaluated in a static mode under different temperature and pressure conditions, ranging from 13-52 degrees C and from 50-220 bar, whether the CO(2)was in its liquid or SC state. It was shown that the compounds which are mixtures of various components give rise to a selective extraction of the lower melting point components, as evidenced from thermal analysis of soluble and insoluble fractions of the coating materials.

A supercritical fluid-based coating technology. 3: preparation and characterization of bovine serum albumin particles coated with lipids.

Solvent-free microparticles, loaded with bovine serum albumin as a model protein, were produced using a novel supercritical (SC) fluid-based coating technology. Coating material consists either of trimyristin (Dynasan 114) or of Gelucire 50-02. Microparticles obtained were characterized as regards their morphology, protein content and in vitro release profile. A discontinuous coating made of micro-needles of trimyristin led to an initial burst release of approximately 70% in 30 min. However, a prolonged release of the BSA could be achieved in a phosphate buffer solution at 37 degrees C over a 24 h period from particles coated with Gelucire 50-02. Furthermore, it was shown that BSA does not undergo any degradation after SC CO(2) treatment under the conditions used in the coating process.

Microencapsulation of protein particles within lipids using a novel supercritical fluid process.

Solvent-free microparticles, loaded with a model protein (bovine serum albumin: BSA) have been produced using a novel coating process based on supercritical (SC) fluid technology. Coating material consists of either trimyristin (Dynasan114) or Gelucire50-02, two lipidic compounds having a high melting point. Microparticles were characterized as regards their morphology, protein content and in vitro release profile. A discontinuous coating made of crystalline micro-needles was obtained using Dynasan114. It led to particles with an initial burst release of about 70% in 30 min at 37 degrees C. However, a prolonged release of the protein has been achieved over a 24 h period from particles coated with Gelucire50-02, which produces a more homogeneous, film-forming coating. Furthermore, it was shown that BSA does not undergo any degradation after SCCO2 treatment under the SC conditions used in the coating process.

New approaches for genotyping of Helicobacter pylori based on amplification of polymorphisms in intergenic DNA regions and at the insertion site of the cag pathogenicity island.

The population of the gastric pathogen Helicobacter pylori shows a high degree of genetic diversity. It is well established that heterogeneity at the isolate level is caused by nucleotide transitions within genes, differences in the gene order, and by genetic instability of single genes as well as of a large virulence-associated genomic DNA region, the cag pathogenicity island (PAI). Analysis of intergenic regions with specific PCR-assays developed in this study, revealed that DNA polymorphisms in the noncoding DNA localized in front of the genes ribA and vacA and at the insertion site of the cag PAI contribute to the genetic diversity of H. pylori and are useful for differentiation of individual isolates. Thirteen individual genotypes were identified by PCR analysis of these polymorphic loci in 487, 241, and 182 clinical H. pylori isolates. Sequence analysis revealed that genetic variability in front of genes ribA and vacA, and in the intergenic region at the PAI insertion site is caused by insertion and deletions of so-far-unknown DNA sequences as well as by parts of the H. pylori IS elements IS605 and IS606, respectively. The new genotypes identified could be used to differentiate antrum and corpus isolates from the same patients. Their combination with vacA allele subtypes and with the cagA status allowed to differentiate 140 isolates in 51 subtypes. In 36 cases the corresponding genotype patterns were isolate specific. In summary, the results confirm that DNA polymorphisms in intergenic regions contribute to the genetic diversity of H. pylori. Although individual H. pylori genotypes were not associated with peptic ulcer disease, the PCR-based approaches for their detection developed here should be of use for further investigation of genetic diversity in H. pylori and for epidemiological purposes.

Landscape structure and biological control in agroecosystems

Biological pest control has primarily relied on local improvements in populations of natural enemies, but landscape structure may also be important. This is shown here with experiments at different spatial scales using the rape pollen beetle (Meligethes aeneus), an important pest on oilseed rape (Brassica napus). The presence of old field margin strips along rape fields was associated with increased mortality of pollen beetles resulting from parasitism and adjacent, large, old fallow habitats had an even greater effect. In structurally complex landscapes, parasitism was higher and crop damage was lower than in simple landscapes with a high percentage of agricultural use.

[Small abnormality of the middle ear--a genetically-induced defect?]. / Die kleine Fehlbildung des Mittelohres--ein genetisch bedingter Defekt?

Conductive and sensorineural hearing losses are of genetic origin in 20% to 60% of cases. In general, genetic abnormalities are more often expressed as a sensorineural hearing loss than as a conductive hearing loss. At present several genes for sensorineural hearing loss have been isolated. The most common genetically transmitted forms for isolated conductive hearing losses are otosclerosis and small malformations of the ossicles. To date no genes responsible for these deformations have been isolated. We present a family with four siblings having conductive hearing losses caused by ossification of the stapedial tendon. This finding is suggestive of an autosomal recessive inheritance. The early diagnosis of an hereditary conductive hearing loss contains the possibility for permitting normal development of speech.