[Interceptive treatment of maxillary hypoplasia with the use of bone anchors. A review of the literature]. / Interceptieve behandeling van een maxillaire hypoplasie met behulp van botankers. Een literatuuronderzoek.

A Class III malocclusion is mainly caused by a hypoplastic maxilla and therefore the treatment is principally aimed at stimulating the growth of the maxilla. Disadvantages of conventional treatment methods are that treatment effects are mainly dentoalveolar rather than skeletal and that there is often an increase in the height of the lowerface. Moreover, patients are not always cooperative about wearing extra-oral appliances. Because of these disadvantages, a new treatment approach has been developed which makes use of skeletal anchoring. In this new technique, called 'bone anchored maxillary protraction, bone anchors are placed on both sides of the maxilla and the mandibula, onto which Class III elastics are attached. The literature shows that good results have been achieved with this method. Disadvantages of this method are that the placement of the bone anchors requires a surgical procedure and that complications, like the loosening or breaking of the anchors, can occur.

Genome-wide association analyses of symptom severity among clozapine-treated patients with schizophrenia spectrum disorders.

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia. However, response is highly variable and possible genetic underpinnings of this variability remain unknown. Here, we performed polygenic risk score (PRS) analyses to estimate the amount of variance in symptom severity among clozapine-treated patients explained by PRSs (R2) and examined the association between symptom severity and genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activity. Genome-wide association (GWA) analyses were performed to explore loci associated with symptom severity. A multicenter cohort of 804 patients (after quality control N = 684) with schizophrenia spectrum disorder treated with clozapine were cross-sectionally assessed using the Positive and Negative Syndrome Scale and/or the Clinical Global Impression-Severity (CGI-S) scale. GWA and PRS regression analyses were conducted. Genotype-predicted CYP1A2, CYP2D6, and CYP2C19 enzyme activities were calculated. Schizophrenia-PRS was most significantly and positively associated with low symptom severity (p = 1.03 × 10-3; R2 = 1.85). Cross-disorder-PRS was also positively associated with lower CGI-S score (p = 0.01; R2 = 0.81). Compared to the lowest tertile, patients in the highest schizophrenia-PRS tertile had 1.94 times (p = 6.84×10-4) increased probability of low symptom severity. Higher genotype-predicted CYP2C19 enzyme activity was independently associated with lower symptom severity (p = 8.44×10-3). While no locus surpassed the genome-wide significance threshold, rs1923778 within NFIB showed a suggestive association (p = 3.78×10-7) with symptom severity. We show that high schizophrenia-PRS and genotype-predicted CYP2C19 enzyme activity are independently associated with lower symptom severity among individuals treated with clozapine. Our findings open avenues for future pharmacogenomic projects investigating the potential of PRS and genotype-predicted CYP-activity in schizophrenia.

[Orthodontic-surgical treatment puts an end to temporomandibular dysfunction complaints]. / Orthodontisch-chirurgische behandeling maakte einde aan temporomandibulaire disfunctieklachten.

Late in the last decade of the previous century, an orthodontic-surgical treatment was elected for a 31-years-old woman, who had severe malocclusion and temporomandibular complaints. The skeletal pattern (high angled mandibula) and degenerating joints were considered risk factors for relapse and condylar lysis. Nevertheless, the severity of the malocclusion justified the treatment. The goal was a stable occlusion and the creation ofa smooth articulation to eliminate dysfunction and facilitate later temporomandibular joint treatment with splints if necessary. In the 1990s this was considered state of the art treatment. Eliminating the scissors bite of 27 seemed instrumental in the elimination of the symptoms. Surgery brought the face and the occlusion further in harmony. The final occlusion features only one lower incisor.

Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white spot lesions and dental plaque after orthodontic treatment: a 3-month follow-up.

The effects of casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP) paste vs. control paste on the remineralization of white spot caries lesions and on plaque composition were tested in a double-blind prospective randomized clinical trial. Fifty-four orthodontic patients, with multiple white spot lesions observed upon the removal of fixed appliances, were followed up for 3 months. Subjects were included and randomly assigned to either CPP-ACFP paste or control paste, for use supplementary to their normal oral hygiene. Caries regression was assessed on quantitative light-induced fluorescence (QLF) images captured directly after debonding and 6 and 12 wk thereafter. The total counts and proportions of aciduric bacteria, Streptococcus mutans, and Lactobacillus spp. were measured in plaque samples obtained just before debonding, and 6 and 12 wk afterwards. A significant decrease in fluorescence loss was found with respect to baseline for both groups and no difference was found between groups. The size of the lesion area did not change significantly over time or between the groups. The percentages of aciduric bacteria and of S. mutans decreased from 47.4 to 38.1% and from 9.6 to 6.6%, respectively. No differences were found between groups. We observed no clinical advantage for use of the CPP-ACFP paste supplementary to normal oral hygiene over the time span of 12 wk.

[Pre- and postsurgical orthodontics]. / Pre- en postchirurgische orthodontie.

Presurgical orthodontic treatment may be hampered by anomalous anatomic relations, function and dento-alveolar compensation. A stabilizing, solid postsurgical occlusion requires presurgical dento-alveolar decompensation. Some sagittal overcorrection simplifies postsurgical orthodontic treatment. In distorelations, a diastema created between maxillary lateral incisors and cuspids may be helpful in this respect. The diastema is providing space for overcorrection and consequently the postsurgical orthodontic treatment can be simplified. In mesiorelations, creating additional space is not required because premature frontal contact is not a disturbing factor. Conversely, in short face patients frontal contact is just useful for gaining facial height.

[Risks of orthodontic treatment]. / Risico's van orthodontische behandeling.

Risks of orthodontic treatment identified in the literature are: enamel damage, root resorption, periodontal damage, temporomandibular disorders, tooth devitalization, treatment failure, and relapse. Enamel damage in the form of irreversible demineralization can take place during treatment with fixed appliances in the absence of adequate oral hygiene. Root resorption occurs, but seldom to the point of clinical relevance. Individual susceptibility and genetics are determining factors. Periodontal damage occurs as gingival recessions. Temporomandibular disorders and tooth devitalization hardly occur. Treatment failure is related to the assessed pre-treatment goals and dependent on the knowledge and skills of the care provider, patient-cooperation, and factors beyond anyone's control. Relapse is a common feature, but does not constitute a treatment risk. The greatest risk is a failure to adequately inform the patient concerning all of the (im)possibilities and their consequences.

Diagnostic performance of axillary ultrasound and standard breast MRI for differentiation between limited and advanced axillary nodal disease in clinically node-positive breast cancer patients.

Preoperative differentiation between limited (pN1; 1-3 axillary metastases) and advanced (pN2-3; ≥4 axillary metastases) nodal disease can provide relevant information regarding surgical planning and guiding adjuvant radiation therapy. The aim was to evaluate the diagnostic performance of preoperative axillary ultrasound (US) and breast MRI for differentiation between pN1 and pN2-3 in clinically node-positive breast cancer. A total of 49 patients were included with axillary metastasis confirmed by US-guided tissue sampling. All had undergone breast MRI between 2008-2014 and subsequent axillary lymph node dissection. Unenhanced T2-weighted MRI exams were reviewed by two radiologists independently. Each lymph node on the MRI exams was scored using a confidence scale (0-4) and compared with histopathology. Diagnostic performance parameters were calculated for differentiation between pN1 and pN2-3. Interobserver agreement was determined using Cohen's kappa coefficient. At final histopathology, 67.3% (33/49) and 32.7% (16/49) of patients were pN1 and pN2-3, respectively. Breast MRI was comparable to US in terms of accuracy (MRI reader 1 vs US, 71.4% vs 69.4%, p = 0.99; MRI reader 2 vs US, 73.5% vs 69.4%, p = 0.77). In the case of 1-3 suspicious lymph nodes, pN2-3 was observed in 30.4% on US (positive predictive value (PPV) 69.6%) and in 22.2-24.3% on MRI (PPV 75.7-77.8%). In the case of ≥4 suspicious lymph nodes, pN1 was observed in 33.3% on US (negative predictive value (NPV) 66.7%) and in 38.5-41.7% on MRI (NPV 58.3-61.5%). Interobserver agreement was considered good (k = 0.73). In clinically node-positive patients, the diagnostic performance of axillary US and breast MRI is comparable and limited for accurate differentiation between pN1 and pN2-3. Therefore, there seems no added clinical value of preoperative breast MRI regarding nodal staging in patients with positive axillary US.

[Does orthodontic treatment contribute to oral health?]. / Draagt orthodontische behandeling bij aan de mondgezondheid?

The first part of this article is an edited Dutch summary of the paper "Oral-health-related benefits of orthodontic treatment" by Donald J. Burden in the special issue''Orthodontics: quality of care, quality of life'' in Seminars in Orthodontics (June 2007). Burden carried out a systematic review of the literature on some, historically claimed, beneficial influences of orthodontic treatment, such as reduced susceptibility to dental caries, periodontal disease, temporomandibular dysfunction, and traumatic injury. Based on the results of this review, Burden concludes that the oral health benefits of orthodontic intervention have not been demonstrated. The second part is a critical and balanced commentary on the content of the paper and on Burden's conclusions.

Modification of hemopoietic stem cells of BALB/c mice by Rauscher leukemia virus.

Bone marrow and spleen from Rauscher leukemia virus (RLV) infected BALB/c mice were tested for proliferative activity at various time intervals after infection using the spleen colony assay. Both bone marrow and spleen derived colonies showed a modified maturation behavior. The erythroid colonies were classified into three consecutive stages of maturation according to morphologic criteria. Both bone marrow and spleen derived erythroid colonies exhibited a retardation of maturation upon RLV infection of the donor mice; the spleen derived erythroid colonies showed the most severe changes. RLV itself could not mimic this phenomenon; moreover it was shown by immunofluorescence that only low amounts of RLV were present in the spleen colonies. It is therefore suggested that RLV modifies part of the stem cell compartment leading to a prolonged cycle time of proerythroblasts and hence to a retardation of colony growth.

Increased metallothionein in the liver and kidney of patients with amyotrophic lateral sclerosis.

To evaluate the putative role of metals and trace elements in the pathogenesis of classic amyotrophic lateral sclerosis, we studied the metallothionein levels in liver and kidney samples obtained at autopsy from 24 patients with amyotrophic lateral sclerosis and 18 controls. To assay metallothioneins and copper, cadmium, and zinc bound to metallothioneins, we used high-performance liquid chromatography directly coupled to flame atomic absorption spectrometry. Total cadmium, zinc, and copper concentrations were determined separately with the use of graphite furnace atomic absorption spectrometry with Zeeman background correction. The median liver metallothionein level was 60.3 mg/kg (range, 9 to 318 mg/kg) in the patients with amyotrophic lateral sclerosis and 12.6 mg/kg (range, 0 to 104.5 mg/kg) in the controls. In the kidney, median metallothionein levels were 126.9 mg/kg (range, 44 to 387 mg/kg) in the patients with amyotrophic lateral sclerosis and 64 mg/kg (range, 13.1 to 187 mg/kg) in the controls. Total zinc, cadmium, and copper concentrations, as measured by atomic absorption spectrometry, were not significantly different in patients vs controls. Our finding of elevated metallothionein levels in organs from patients with amyotrophic lateral sclerosis may indicate an increased exposure to metals.

Involvement of SRS-A in the Schultz-Dale response of the guinea-pig small intestine.

1 The anaphylactic reaction of the guinea-pig ileum, the so called Schultz-Dale reaction, shows a biphasic response: a short rapid contraction followed by a partial relaxation and a slow contractile response. 2 Dose-response curves with ovalbumin as an antigen were obtained for the quick and slow contraction of this anaphylactic reaction. 3 Mepyramine (1 microgram/ml) blocked the rapid first contraction, but failed to abolish the slow one in about 50% of the animals studied. 4 The SRS-A antagonist, FPL 55712, significantly depressed the slow sustained contraction during the Schultz-Dale reaction. Disodiumcromoglycate was without effect on both phases when it was added 5 min before addition of the antigen. However, when added simultaneously with the antigen it produced a 30% suppression of the slow phase in the highest concentration used.

The precedence effect for lateralization at low sensation levels.

Using dichotic signals presented by headphone, stimulus onset dominance (the precedence effect) for lateralization at low sensation levels was investigated for five normal hearing subjects. Stimuli were based on 2400-Hz low pass filtered 5-ms noise bursts. We used the paradigm, as described by Aoki and Houtgast (Hear. Res., 59 (1992) 25-30) and Houtgast and Aoki (Hear. Res., 72 (1994) 29-36), in which the stimulus is divided into a leading and a lagging part with opposite lateralization cues (i.e. an interaural time delay of 0.2 ms). The occurrence of onset dominance was investigated by measuring lateral perception of the stimulus, with fixed equal duration of leading and lagging part, while decreasing absolute signal level or adding a filtered white noise with the signal level set at 65 dBA. The dominance of the leading part was quantified by measuring the perceived lateral position of the stimulus as a function of the relative duration of the leading (and thus the lagging) part. This was done at about 45 dB SL without masking noise and also at a signal-to-noise ratio resulting in a sensation level of 10 dB. The occurrence and strength of the precedence effect was found to depend on sensation level, which was decreased either by lowering the signal level or by adding noise. With the present paradigm, besides a decreased lateralization accuracy, a decrease in the precedence effect was found for sensation levels below about 30-40 dB. In daily-life conditions, with a sensation level in noise of typically 10 dB, the onset dominance was still manifest, albeit degraded to some extent.

Determination of copper, iron, manganese, lead and cadmium in automatically wet-digested animal tissue by graphite-furnace atomic-absorption spectrometry with zeeman background correction.

An efficient wet digestion method is described which allows the determination of various elements in animal tissues. Copper, iron, manganese, lead and cadmium in one dilution of the digested sample can be determined by means of graphite-furnace atomic-absorption spectrometry, with Zeeman background correction. Tests with the National Bureau of Standards Bovine Liver SRM as reference gave analytical results, obtained with calibration graphs as well as by the standard-addition method, which agreed well with the certified values.

A compact body mass measuring device for space flight applications.

During spaceflights, it is important to measure an astronaut's body mass ('weight'), both for investigating the influence of the space environment on the human body and for monitoring the physical (health) condition of the astronaut. This paper reports the development of a mass measuring device that is compact, user friendly, and has an absolute measuring accuracy better than 60 gram. The measurement accuracy turns out to be restricted by the way a human body is configured by nature and not by the instrument itself, that has an accuracy much better than required.

Environmental contamination by heavy metals and fluoride in the Saeftinge salt marsh (The Netherlands) and its effect on sheep.

The Saeftinge salt marsh in the Westerschelde estuary (southwestern part of the Netherlands) represents one of the very few tidal brackish marsh ecosystems in Western Europe. From May 1983 to May 1985 the local pollution of this marsh with metals and fluoride was investigated. Samples from soil and vegetation were analysed monthly for cadmium, lead, copper, zinc, manganese, iron, and fluoride. The amount of these substances in the soil appeared to be related to both the percentage of clay particles and organic matter in the soil and to the frequency of tidal submergences. In vegetation, the pollutants clearly showed a seasonal variation. Adherent clay, deposited on the plants during submergences, contributed considerably to the total amount of these elements. Sheep grazing in the marsh were investigated for renal and faecal excretion of these elements, but no relation between these samples and the seasonal variation in vegetation was found. Presumably sheep consumed vegetation selectively, avoiding the more contaminated plants. Regular clinical inspections of the sheep revealed no signs of acute or chronic intoxication. The organs of sheep that died during the investigation showed increased levels of cadmium in the liver and kidney, and iron in the liver, but not enough to cause alarm. Fluoride found in the rib material, although slightly increased, did not indicate fluorosis. In conclusion, contamination with metals and fluoride, as observed in the salt marsh, apparently does not impair the health of locally grazing sheep. This may be due to selective consumption behaviour of the sheep, their stabling during the winter, limited biological availability of the elements studied, and a sheep management adapted to the local circumstances.

[A case of selenium poisoning in piglets]. / Een geval van seleniumvergiftiging bij biggen.

Acute paralysis was observed in suckling piglets and weaner piglets on a pig breeding farm. Pathomorphological investigations revealed characteristic lesions in the central nervous system. These lesions were indicative of selenium poisoning. This was verified by chemical-toxicological analysis of organs and tissues of the affected pigs. Poisoning was shown to have been caused by the feed: one feed preparation contained an extremely large amount of selenium, which was due to human failure.

[Lead poisoning in cattle in north Netherlands. October 1989-January 1990]. / Loodintoxicatie bij rundvee in Noord-Nederland. Oktober 1989-januari 1990.

By the end of 1989 a serious lead intoxication of cattle occurred in the northern part of the Netherlands (provinces Groningen and Friesland). This intoxication appeared to be caused by contaminated feed. Over 300 farms were stricken, with about 15,500 animals (mostly dairy cattle). In a period of one to four weeks these animals consumed about 1,000 kg of lead. This resulted in lead levels in milk, livers, and kidneys above the regulatory safety limits. Thanks to the chelating therapy that was rapidly applied by the local veterinarians, only about 30 animals died of an acute lead intoxication. The cooperating governmental and private authorities took action to prevent exposure of consumers to lead-contaminated animal products. Based on careful estimations, predictions were made of the lead levels to be expected in animals products and the time needed for depletion of these levels. The appropriate animals were marked to ensure their identification, and the decline in time of the lead levels in milk and offals was conscientiously monitored. In the second week of 1990 the lead concentrations were decreased to levels well below the regulatory limits, and hence the marks were removed from the animals.