A glutamate receptor-interacting protein homolog organizes muscle guidance in Drosophila

During Drosophila embryogenesis, developing muscles extend growth-cone-like structures to navigate toward specific epidermal attachment sites. Here, we show that the homolog of Glutamate Receptor-Interacting Proteins (DGrip) acts as a key component of proper muscle guidance. Mutations in dgrip impair patterning of ventral longitudinal muscles (VLMs), whereas lateral transverse muscles (LTMs) that attach to intrasegmental attachment sites develop normally. Myoblast fusion, stabilization of muscle contacts, and general muscle function are not impaired in the absence of DGrip. Instead, the proper formation of cellular extensions during guidance fails in dgrip mutant VLMs. DGrip protein concentrates at the ends of VLMs while these muscles guide toward segment border attachment sites. Conversely, LTMs overexpressing DGrip form ectopic cellular extensions that can cause attachment of these muscles to other muscles at segment borders. Our data suggest that DGrip participates in the reception of an attractive signal that emanates from the epidermal attachment sites to direct the motility of developing muscles. This dgrip phenotype should be valuable to study mechanistic principles of Grip function.     

Generation of functional Cerec 3D occlusal surfaces: a comparison of two production methods relevant in practice

The introduction of the Cerec 3D software (R 1500) promised the generation of functional occlusion points and proximal contacts on the basis of a 3-dimensional virtual model on the screen. The objective of this in vitro study was to check this claim in the simulated chairside production of a single tooth restoration. Furthermore, the differences both in conventional finishing and in ceramic glazing were to be determined. For the operator, the latter should simplify or shorten the intraoral finishing and polishing of the occlusal surface, or make it superfluous. To check the suitability of the two methods, these were compared with regard to their quality and the time required to perform them. Ten cavities on articulated models, representing real clinical cases, were each provided with two restorations. One was produced with the glazing method (group A), the other conventionally (group B). The Cerec 3D software, version R 1500, was used for designing the restoration. The restorations made from Vita Mark II ceramic blocks were finished with fine diamond instruments and polished with Sof-Lex disks when using the conventional method. In the alternative method, finishing was practically replaced by glazing the surface. The restorations were evaluated in the articulator, considering both the vertical relation at the incisal pin as well as the accurate position of the contact points. The study showed that functional rehabilitation was possible and no significant qualitative differences occurred in the methods. In this in vitro study, it was found that the glazing method reduced the time required by the operator by around 20% and indicates an improvement in quality. The results of this study promise simplification when the glazing method is used clinically.     

Complement component C7 deficiency in two Spanish families

Different genetic mutations have been described in complement component C7 deficiency, a molecular defect clinically associated with an increased susceptibility to neisserial recurrent infections. In this work we report the genetic basis of C7 deficiency in two different Spanish families (family 1 and family 2). In family 1, of Gypsy ethnical background, exon-specific polymerase chain reaction and sequencing revealed a not previously described single base deletion of nucleotide 1309 (exon 10) in the patient, as well as in her father, leading to a stop codon that causes the premature truncation of the C7 protein (K416 X 419). Additionally, the patient and her mother displayed a missense mutation at position 1135 (exon 9) located in the first nucleotide of the codon GGG (CGG), resulting in a change of amino acid (G357R). This mutation was firstly described in individuals of Moroccan Sephardic Jewish ancestry and has been also reported among Spaniards. In family 2, another novel mutation was found in homozygosity in two siblings; a two base-pair deletion of nucleotides 1922 and 1923 in exon 14 leading to the generation of a downstream stop codon causing the truncation of the C7 protein product (S620 X 630). Our results provide more evidence for the heterogeneous molecular basis of C7 deficiency as well as for the subsequent susceptibility to meningococcal disease, since different families carry different molecular defects. On the other hand, certain C7 defects appear to be prevalent in individuals from certain populations or living in defined geographical areas.     

A method to record changes in local neuronal discharge in response to infusion of small drug quantities in awake monkeys

A newly designed combination microelectrode-injection system is described which can be used to record electrophysiological responses of individual neurons in the primate brain to local administration of small quantities of drugs or other compounds. The assembly of the system is simple, and the materials used are inexpensive. The system consists of a standard tungsten microelectrode alongside fused silica tubing within a polyimide sleeve. The major advantage of this device is the ability to record with excellent quality, changes in the activity of single cells in vivo within 50-100 microm of the location of drug injections.     

Anatomy of the visual system

This brief systemic overview presents the anatomic details of the orbit with respect to imaging modalities CT and MR. The structures of the four orbital compartments, intrakonal and extrakonal space, globe and optic nerve are demonstrated in detail on different CT and MR views (axial, coronal, in soft tissue and bone window, T1-weighted, T2-weighted) with corresponding diagrams. The intracranial visual pathway is explained in detail with emphasis to the striate cortex and extrastriate visual association cortex, presented with diagrams and high-resolution MR.     

Health impacts of second-hand exposure to cat allergen Fel d 1 in infants

BACKGROUND: Recent cross-sectional studies suggested that highest sensitization prevalences occur with moderate cat allergen exposures. We aimed to assess the impact of moderate levels of second-hand cat allergen exposure on the incidence of specific sensitization and wheezing in the framework of a birth cohort study. Therefore we restricted our analysis to infants without a cat at home since birth. METHODS: At infant's age 3 months, cat allergen levels were measured in the mattress dust of 1840 families without cats. At age 2 years, serum IgE specific to Fel d 1 was analyzed. Incidence of wheezing apart from respiratory infection was assessed by questionnaire. Logistic regression models were used to calculate adjusted odds ratios (OR) for the association between second-hand cat allergen exposure and health outcomes. RESULTS: Until age 2 years, 13 of 1301 infants (1%) were sensitized to cat allergen and 56 of 1492 infants (4%) had ever-wheezing without infection. Early exposure to second-hand cat allergen levels >or= 1 microg/g dust increased substantially the risk for specific sensitization to Fel d 1 (OR 10.9, 95% CI 3.4-35.0) and ever-wheeze without infection (OR 2.0, 95% CI 1.1-3.9) at age 2 years. CONCLUSIONS: Second-hand exposure to cat allergen in homes without cats is detrimental in terms of allergy development in infants.     

Imaging of periimplant bone levels of implants with buccal bone defects

The aim of the present study was to use four different methods to evaluate three radiographic techniques for their accuracy in assessing the marginal periimplant bone levels at implants with buccal bone defects in an experimental setting. Twenty-four implants were placed in the mandibles of six adult beagle dogs with substantial buccal bone defects, which were augmented by bone particles with and without resorbable membranes. After healing for 5 months, (1) periapical radiographs, (2, 3) reformatted images in (2) sagittal and (3) coronal planes from axial computer tomography (CT) scans and (4) direct magnification images (DIMA) were made and compared with histometric analysis of bone levels. Two values were used for comparison: (i) the lingual bone level and (ii) the true bone level calculated as a mean value from the lingual and the buccal bone levels of all histologic sections of each implant. Metric evaluation of periapical radiographs, sagittal reformation of CT scans and DIMA showed that the results were close to the histometrically assessed lingual bone level, while the true bone level was significantly lower and not reflected by any of the imaging modalities. Coronal reformation showed that there was significant overestimation of the lingual and underestimation of the buccal bone level when compared with histometric values. It is concluded that assessment of bone level and bone regeneration in implants with buccal bone defects remains problematic, and data from periapical radiograms tend considerably to overestimate the bone anchorage of these implants.     

Beeinflussung des Stillverhaltens durch familiäre atopische Vorbelastung und unterschiedliche Information über atopiepräventive Ernährung

Background. For all infants exclusive breastfeeding is recommended during the first 4 to 6 months of life.This study analysed how this recommendation is followed in children differing with regard to family history of atopic diseases.Furthermore it was evaluated whether additional information about allergy-preventive nutrition or whether other factors, such as sociodemographic differences and smoking, influence breastfeeding habits. Methods. Data of children in the GINI-study, born between 01.01.1996 and 30.06.1998, were analysed.This study includes an intervention group and a control group,which differ in family history of atopic diseases and information about nutrition.The family history of atopic diseases and sociodemographic factors were recorded at enrollment. Breastfeeding and smoking patterns were evaluated after the first year of life. Results. Data of 4578 children were evaluated. 50,4% of the infants were exclucively breastfed in the first 4 months of life. Infants were significantly more likely to be breastfed if they were part of the intervention group (OR=1,24; KI=1,04–1,48), had mothers older than 30 years of age (OR=1,53;KI=1,29–1,81), had parents with higher education (OR=2,01; KI=1,56–2,59), and came from the region of Munich compared to Wesel (OR=1,4; KI=1,18–1,67). Smoking of the mother had a strong negative influence on breastfeeding (OR=0,23; KI=0,17–0,3).No influence was found with respect to the family history of atopic diseases (OR=1,06; KI=0,89–1,26), citizenship, number of siblings and gender. Conclusions. Although breastfeeding is recommended in the prevention of atopy, it is not more often done in children with a family history of atopic diseases.The influence of nutritional councelling after birth was less than that of sociodemographic differences and smoking habits.     

Association of lung function with declining ambient air pollution

Recent studies have found a declining prevalence of respiratory infections in East German children, along with a tremendous improvement of air pollution since 1990. The present study evaluates the effects of improved air quality on lung function. Three consecutive cross-sectional surveys of schoolchildren ages 11-14 years from three communities in East Germany were performed in 1992-1993, 1995-1996, and 1998-1999. Lung function tests were available from 2,493 children. The annual mean of total suspended particulates (TSP) declined from 79 to 25 micro g/m(3), whereas levels for sulfur dioxide declined from 113 to 6 micro g/m(3). Mean forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV(1)) of the children increased from 1992-1993 to 1998-1999. The adjusted percent change of the geometric mean of FVC was 4.7% for a 50 micro g/m(3) decrease of TSP (p = 0.043) and 4.9% for a decrement of 100 micro g/m(3) SO(2) (p = 0.029). Effects on FEV(1) were smaller and not statistically significant. Our study indicates that a reduction of air pollution in a short time period may improve children's lung function.