A new radioimmunoassay for human mast cell tryptase using monoclonal antibodies

A solid phase immunoradiometric assay was developed for the quantitation of tryptase released from activated human mast cells. Tryptase exhibits a linear dose-response curve over the standard range of 2-50 micrograms/l in buffer, serum, and plasma. The dose-response curve approached a plateau at a tryptase concentration of 100 micrograms/l and exhibited partial inhibition at concentrations above 10,000 micrograms/l. The sensitivity of the assay was 0.2-0.4 micrograms/l, and the intra-assay and interassay coefficients of variation were below 4% at 2 micrograms/l or higher tryptase concentrations. The recovery of known amounts of purified tryptase added to serum ranged from 91 to 115%. Detection of tryptase was evaluated with several body fluids and was accurate in sera, plasma, bronchoalveolar lavage fluid, nasal lavage fluid, and saliva. The concentration of tryptase was examined in serum samples from 100 healthy controls; in each case the level was less than 2 micrograms/l. The immunoassay also was utilized to examine serum levels of tryptase after the onset of a hypotensive reaction in one patient receiving general anesthesia. A maximally elevated level of tryptase (25 micrograms/l) was detected at the first time point, 0.5 h, and elevated levels persisted to 6 h before a return to normal levels was documented at 24 h. Thus, the involvement of mast cell activation in hypotensive subjects can be ascertained by this new tryptase radioimmunoassay.     

Working memory brain activity and capacity link MAOA polymorphism to aggressive behavior during development

A developmental increase in working memory capacity is an important part of cognitive development, and low working memory (WM) capacity is a risk factor for developing psychopathology. Brain activity represents a promising endophenotype for linking genes to behavior and for improving our understanding of the neurobiology of WM development. We investigated gene–brain–behavior relationships by focusing on 18 single-nucleotide polymorphisms (SNPs) located in six dopaminergic candidate genes (COMT, SLC6A3/DAT1, DBH, DRD4, DRD5, MAOA). Visuospatial WM (VSWM) brain activity, measured with functional magnetic resonance imaging, and VSWM capacity were assessed in a longitudinal study of typically developing children and adolescents. Behavioral problems were evaluated using the Child Behavior Checklist (CBCL). One SNP (rs6609257), located ∼6.6 kb downstream of the monoamine oxidase A gene (MAOA) on human chromosome X, significantly affected brain activity in a network of frontal, parietal and occipital regions. Increased activity in this network, but not in caudate nucleus or anterior prefrontal regions, was correlated with VSWM capacity, which in turn predicted externalizing (aggressive/oppositional) symptoms, with higher WM capacity associated with fewer externalizing symptoms. There were no direct significant correlations between rs6609257 and behavioral symptoms. These results suggest a mediating role of WM brain activity and capacity in linking the MAOA gene to aggressive behavior during development.     

Cell cycle progression of B-chronic lymphocytic leukemia cells induced to differentiate by TPA

The cell cycle transition and differentiation-associated surface antigen expression was studied in a clone of B cell chronic lymphocytic leukemia (B-CLL) with phenotypic properties similar to those of resting B lymphocytes. Differentiation was induced with TPA (12-O-tetradecanoyl- phorbol-13-acetate) and defined and quantitated by morphological and functional markers. Changes in the cell cycle position were determined by flow cytometry of acridine orange-stained cells. The uninduced B-CLL cells represented a homogeneous population with the same cell cycle position (GO) as resting normal peripheral blood lymphocytes. After five days of TPA stimulation, 56% of the B-CLL cells were found in G1A, 9% in G1B, and 3% in the S + G2/M phase, of which 2% was accounted to proliferating T cells. The cell cycle transition of the differentiating B-CLL cells was also examined using cell cycle-associated surface antigens as markers. HLA-DR and CD23 antigens were present already on noninduced cells. The former had a high constant expression, while the amount of CD23 increased upon induction. The 4F2 antigen was absent on noninduced cells but present on 86% of the induced cells. HH1 (CD37) was expressed by the majority of the cells before TPA treatment and decreased to almost undetectable levels within 24 hours. Two antigens related to late stages of the cell cycle, the interleukin 2 (IL 2; CD25) and the transferrin receptor, were present on about 20% of the induced cells. Experiments with enriched T cells showed that T but not B cells incorporated 3H-thymidine. Taken together these results and previous work on the induction of the protooncogene c-myc and c-fos suggest that this B-CLL clone represents GO cells that undergo differentiation without concomitant proliferation when exposed to TPA.     

Oral versus rectal midazolam as a pre-anaesthetic sedative in children receiving dental treatment under general anaesthesia

Dental treatment in children who are too young or too apprehensive to cooperate is often performed under sedation. In Sweden, the tradition has been to administer sedatives rectally in small children, but oral liquid sedation is now increasingly used. AIM: To compare the sedative effects of oral and rectal administration of midazolam in children undergoing dental treatment under general anaesthesia and to assess acceptance of sedative administration, acceptance of application of the facemask, and amnesia. METHODS: Fifty children aged 2-7 y were randomly allocated to receive either liquid oral or rectal sedation, with 25 children in each group. RESULTS: The sedative effect of rectal administration was higher, but not statistically significantly, than that of oral administration (p = 0.07). No significant differences in acceptance of sedative administration, acceptance of mask application or amnesia were found between the groups. CONCLUSION: Both the oral and the rectal routes can in most cases be appropriate. However, the better sedative effect of rectal administration of midazolam makes it a more favourable route in pre-cooperative and non-compliant children.     

Periodontal conditions in a group of Swedish adolescents (I). A descriptive epidemiologic study

The aim of the present study was to describe, clinically and radiographically, the periodontal conditions in 16- and 18-year-old adolescents from Northern Sweden. The studied samples comprised 287 16-year-olds and 283 18-year-olds. The clinical examination included recording of presence of plaque, bleeding on probing and calculus, and measurements of attachment level and pocket depth. Alveolar bone level was measured on bite-wing radiographs. A history was taken of the individual's occupation, oral hygiene habits and tobacco use, health, medication and previous orthodontic treatment. The prevalence of attachment loss (AL) was 9.4% in the 16-year-olds and 19.4% in the 18-year-olds. Proximal AL was found in 2.8% and 4.9%, respectively, and proximal bone loss in 1% in both groups. With only a few exceptions (3 individuals out of 82), the individuals with AL had their loss either at buccal/lingual surfaces or at proximal surfaces. Calculus was present in 32.7% of the 16-year-olds and in 44.9% of the 18-year-olds. Pocket greater than 3 mm were found in 4%. No significant differences concerning the periodontal status or presence of plaque and calculus were detected between urban and rural groups or between sexes. Toothbrushing 2 or more times/day was performed by 84.3% of the 16-year-olds and by 83.7% of the 18-year-olds.     

A new experimental model for studies of local inflammatory reactions.

The aim of the present study was to develop and evaluate a method for studies of the early phase of the local inflammatory reaction, based on continuous diffusion of an inflammatory inducing agent. 25 rats were used. Four sterile teflon tablets were implanted subcutaneously in the back of each animal. After 3 weeks, when a connective tissue capsula had formed, the tablets were replaced by two test tablets, containing 35 micrograms lipopolysaccaride, one placebo and one teflon tablet. Five rats were sacrificed on day 0, 4, 7, 14, 21, respectively, and biopsies comprising tablet and surrounding tissue were harvested and exposed to routine histologic treatment. The number of leucocytes was assessed in four defined areas adjacent to each tablet. During the first seven days an increase in the number of leucocytes was seen in the tissues adjacent to test tablets. After 14 and 21 days the number of leucocytes was still high but lower as compared to day 7. In the tissues bordering the placebo and teflon tablets only few inflammatory cells were found. The results suggest that the tested method is suitable for studies of local inflammatory reactions during a 21 day period in experimental animals.     

High Throughput Screening of a Prescription Drug Library for Inhibitors of Organic Cation Transporter 3, OCT3

Pharmaceutical Research - The organic cation transporter 3 (OCT3, SLC22A3) is ubiquitously expressed and interacts with a wide array of compounds including endogenous molecules, environmental...     

Marginal bone level in the normal primary dentition

Abstract The aim of the present study was to establish the normal range for the radiographic distance between the cemento-enamel junction (CEJ) and the marginal bone level (MBL) in the primary dentition, and to relate this distance to various physiological and pathological factors. 128 children at the ages 7, 8 and 9 years took part in the study. Clinical and radiographic examinations of the mesial and distal surfaces of all primary molars and the distal surface of the primary canines were performed. The clinical examination included measurements of the amounts of plaque, bleeding on probing, probing depth and probing attachment loss. In addition, increased mobility of the primary teeth and stage of eruption of the neighbouring permanent teeth were recorded. The radiographic examination included measurements of the CEJ-MBL distance and the remaining root length. Also, exfoliating teeth, presence of proximal dentin caries, restorations and calculus were recorded from the radiographs. Associations between various explanatory variables and the CEJ-MBL distance were tested with both a X² test and a variance components analysis. The mean CEJ-MBL distance for all primary tooth surfaces was 1.0 mm. Individual surfaces displayed distances ranging from 0.0–0.4 mm. Of the variables tested for association with the CEJ-MBL distance, eruption of neighbouring permanent tooth and exfoliation of neighbouring primary tooth seemed to be associated with large CEJ-MBL distances. When surfaces with these characteristics were excluded, a CEJ-MBL range of 0.0–2.0 mm was obtained. Based on these findings, it seems reasonable to consider sites with a distance of > 2 mm to have pathological bone loss, providing the above physiological conditions related to large CEJ-MBL distances are taken into consideration.     

Histopathology of initial gingivitis in humans

Abstract The present study concerns the inflammatory alterations in the gingival margin during initial gingivitis in 11–13 year old human subjects. At day 0 of the experiment, all participants had clean teeth and healthy gingiva. All active oral hygiene measures were excluded for 4 days. From upper and lower premolars, which were extracted for orthodontic reasons, contralateral gingival biopsies, including the tooth and the adjacent gingiva, were obtained on days 0 and 4. The presence of inflammatory cells in the junctional epithelium and the adjacent connective tissue was determined quantitatively in semi-thin sections. The collagen content of the gingival margin was also determined. From day 0 to day 4 there was only a slight increase in the number of neutrophilic granulocytes in the junctional epithelium and adjacent connective tissue, while a more pronounced increase was found in the number of mononuclear leukocytes. A loss of collagen was noticed in 4 of the subjects, while 2 did not show any changes in collagen content. The inflammatory reaction seen in the present study differs somewhat from that observed in adult humans and adult dogs. The results correspond more to the reaction seen in juvenile dogs.     

Caries-preventive effect of an oral health program for preschool children in a low socio-economic, multicultural area in Sweden: results after one year

The aim of this study was to evaluate the caries-preventive effect of an oral health program for preschool children living in a multicultural, low socio-economic area. In total, 804 2-year-old children were invited and recalled every 3rd month to an outreach facility for parent education and toothbrushing instruction. In addition, fluoride tablets (0.25 mg/day) were provided free of charge. A clinical examination and questionnaire were completed at baseline and at age 3 years. The results of the intervention were compared with a non-intervention Reference group of 3-year-old children (n=217) from the same area. In the Intervention group, the 1-year attrition rate was 8.2%, and more than 90% of the children attended at least 4 of their scheduled appointments. The parents' daily assistance with toothbrushing and the use of fluoride toothpaste and tablets improved significantly during the intervention. Compared with the Reference group when the children were 3 years old, the number of children in the Intervention group who consumed frequent in-between meals and sweet drinks at night was significantly lower. Caries prevalence at age 3 was significantly lower in the Intervention group than in the Reference group (3.0 deft versus 4.4 deft; p<0.01). The number of caries-free children after the 1-year intervention was 37% in the Intervention group compared with 15% in the Reference group. The relative risk (RR) was calculated to be 2.5 (95% CI 1.8-3.4) and the number needed to treat (NNT) 4.6. In conclusion, this study demonstrated that the oral health program significantly affected the prevalence of caries and various risk factors for caries development.