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Biomedical subjects

A Lundström

Publications and source records attributed to A Lundström.

At least 19 recordsLinked to original sources

A protein from the cabbage looper, Trichoplusia ni, regulated by a bacterial infection is homologous to 3-dehydroecdysone 3beta-reductase.

During the screening of immune-regulated genes from the cabbage looper, Trichoplusia ni, a 3-dehydroecdysone 3beta-reductase homologue (DERH) was cloned. In the course of development, 3-dehydroecdysone 3beta-reductase mediates the conversion of 3-dehydroecdysone (3dE) secreted from the prothoracic glands to ecdysone (E), which is subsequently converted to 20-hydroxyecdysone (20E), the major insect molting hormone. The cloned gene is upregulated in fat body during development and is strongly induced after the larva is challenged with bacteria. The gene codes for a 308 amino acid residue protein which shows 42.5% identity to Spodoptera littoralis 3-dehydroecdysone 3beta-reductase. Using the baculovirus expression system, the recombinant DERH was expressed. The purified protein mediates the reduction of 3-dehydromakisterone A to makisterone A, and requires NADPH as a cofactor. Western blots using an antiserum to T. ni DERH revealed the presence of the protein in larval hemolymph and integument. The data indicate that the protein is regulated developmentally and is induced after a challenge with bacteria. Immunohistochemical studies localized the enzyme exclusively in the epidermis and the cuticle.

3-Hydroxysteroid Dehydrogenases↗

Trichoplusia ni gloverin, an inducible immune gene encoding an antibacterial insect protein.

By using differential display PCR, we obtained a cDNA clone encoding a gloverin homologue from the cabbage looper, Trichoplusia ni. The expression of the gene was induced by bacterial infections. The gene codes for a 174 amino acid residue protein, including a signal sequence and a prosegment. The deduced mature protein is 14 kDa and shows 58% and 49% identity to P2 from Helicoverpa armigera and to Hyalophora gloveri gloverin, respectively. The protein was detected in hemolymph and hemocytes from bacteria-immunized animals. We expressed gloverin using the baculovirus expression system. N-terminal amino acid sequence analysis showed that the purified protein contained a propart. This progloverin inhibited the growth of E. coli and the activity is comparable to that of H. gloveri mature gloverin. Processing of progloverin was possible in vitro, using human furin.

Amino Acid Sequence↗

Periodontal conditions in 70-year-old women with osteoporosis.

The aim of the present study was to examine the periodontal conditions in an age cohort of 70-year-old women and compare an osteoporosis group with a control group with normal bone mineral density. 210 women 70 years old and randomly sampled from the population register of the community of Linköping were examined. Bone mineral density (BMD) of the hip was measured by dual energy X-ray absorptiometry. 19 women were diagnosed with osteoporosis (BMD below 0.640 g/cm2 in total hip). 15 of them accepted to participate in the study. As a control group 21 women with normal bone mineral density (BMD exceeding 0.881 g/cm2) were randomly selected from the initial population. The clinical examination included registration of the number of remaining teeth, dental plaque and periodontal conditions. The radiographic examination included a dental panorama and vertical bite-wing radiographs. The subjects also answered a questionnaire about their general health, age at menopause, concurrent medication, smoking and oral hygiene habits. The results from this study showed no statistically significant differences in gingival bleeding, probing pocket depths, gingival recession and marginal bone level between the women with osteoporosis and the women with normal bone mineral density. In conclusion, the present randomly selected and controlled study of osteoporotic and non-osteoporotic women, showed no statistically significant differences in periodontal conditions or marginal bone level. As periodontitis as well as osteoporosis are associated with age, our study of a well-defined age cohort is of interest, but the results should be interpreted with caution since the compared groups are small.

Absorptiometry, Photon↗

The role of alpha2 beta1 and alpha3 beta1 integrin receptors in the initial anchoring of MDA-MB-231 human breast cancer cells to cortical bone matrix.

Molecular mechanisms involved in the rapid attachment of the human breast cancer cell line MDA-MD-231 to cortical bone matrix were studied. The attachment of MDA-MD-231 cells to cortical bone disks could be blocked by 75% when cells were pretreated with a monoclonal antibody to the beta1-subunit of the integrin family. Monoclonal antibodies against the alpha2, alpha3, and alpha5 integrin subunits inhibited the attachment by 76, 26, and 8 % respectively. Collagenase type I and collagen type I antibody blocked the cell attachment by 45 and 50 % whereas pretreatment of the cells with soluble collagen type I blocked the attachment by 85 %. Our study with a panel of cancer cell lines further showed a close correlation between alpha2 beta1 and alpha3 beta1 integrin receptor expression and the capability to attach to cortical bone. These receptors appear to be the key receptors utilized by cancer cells for the initial attachment to cortical bone, and this could facilitate the localization of alpha2 beta1 and alpha3 beta1 expressing cancer cells to the skeleton.

Animals↗

A peptidoglycan recognition protein in innate immunity conserved from insects to humans.

Innate nonself recognition must rely on common structures of invading microbes. In a differential display screen for up-regulated immune genes in the moth Trichoplusia ni we have found mechanisms for recognition of bacterial cell wall fragments. One bacteria-induced gene encodes a protein that, after expression in the baculovirus system, was shown to be a peptidoglycan recognition protein (PGRP). It binds strongly to Gram-positive bacteria. We have also cloned the corresponding cDNA from mouse and human and shown this gene to be expressed in a variety of organs, notably organs of the immune system-i.e., bone marrow and spleen. In addition, purified recombinant murine PGRP was shown to possess peptidoglycan affinity. From our results and the sequence homology, we conclude that PGRP is a ubiquitous protein involved in innate immunity, conserved from insects to humans.

Amino Acid Sequence↗

A proportional analysis of some facial height and depth variables in 10 to 16 year old children.

A method for analysing the horizontal and vertical proportions of the face is described, based on natural head orientation (NHO). It demonstrates how individual deviations from the mean proportions can be quantified both horizontally and vertically. Correlation between facial depth to height (index 1) and the mandibular plane angle was determined and found to be fairly strong and highly significant (r = 0.5, P < 0.001). Facial depth to height and lower facial height to total facial height (index 2) relationships were found to be strongly correlated at each age between 10 and 16 years, with only small mean differences. For this reason the norm values presented for 12-year-old children for indices 1 and 2 should be applicable to orthodontic patients within this age range. The relationship between mandible and maxilla (index 3) increases continually between 10 and 16 years in boys, and between 10 and 14 years in girls, about 0.3 units a year. It can provide supplementary information for individual case analysis. For boys the increase was 2.2 units per year between 14 and 16 years of age.

Adolescent↗

Trichoplusia ni attacin A, a differentially displayed insect gene coding for an antibacterial protein.

The mRNA differential display method was used to isolate antibacterial defense genes from Trichoplusia ni. The mRNA population in last-instar T. ni larvae injected with bacteria was compared to that of untreated larvae. Using a PCR amplified probe corresponding to an induced mRNA, we were able to clone an attacin homolog from a lambda cDNA library from vaccinated larvae. The corresponding protein showed 63% identity to Hyalophora cecropia acidic attacin. The induction kinetics of T. ni attacin A gave optimal mRNA levels at 20 h post-infection. Genomic analysis showed this to be a single-copy gene with two introns.

Amino Acid Sequence↗

The Frankfort horizontal as a basis for cephalometric analysis.

A random sample of 79 British 12-year-old children was studied from tracings registered in the natural head position (NHP). The angle between the Frankfort horizontal (FH) and the horizontal at right angles to the plumb line was measured. Two experienced assessors checked every tracing; for those children perceived to show unnatural head position this was adjusted to what they considered to be the natural head orientation (NHO). The NHO was defined as the head orientation of the subject perceived by the clinician, based on general experience, as the NHP in a standing, relaxed body and head posture, when the subject is looking at a distant point at eye level. The FHK horizontal angle was then measured, now related to the corrected head position. The standard deviation for the latter angle was smaller than that of the uncorrected, but still too large for the FH to be considered reliable as a basis for clinical cephalometric analysis. No statistically significant difference in variability as found between FH and the sella-nasion line. The extracranial horizontal plane related to NHO was recommended as the least variable of the references studied.

Cephalometry↗

Natural head position and natural head orientation: basic considerations in cephalometric analysis and research.

Natural head position (NHP) provides the key for meaningful cephalometric analysis because an extracranial reference line is used instead of intracranial reference lines, known to be subject to considerable biological variation in their inclination. Although the principle of natural head position is being recognized in the orthodontic literature, its registration may contain an element of unavoidable error that requires correction. A new concept of natural head orientation (NHO) has been introduced to maximize the contribution of NHP to cephalometrics. It is defined as the head orientation of the subject perceived by the clinician, based on general experience, as the natural head position in a standing, relaxed body and head posture, when the subject is looking at a distant point at eye level. The present study was designed to determine the accuracy and validity of NHO, using lateral profile photographs cut in a circular shape, obtained from 27 orthodontic patients, 10-14 years old. Findings among four investigators showed a high correlation (r = 0.82-0.96), in orientating these profile photographs in estimated natural head position (NHP). Moreover, investigators showed good correlation (r = 0.57-0.84) in head orientation after a 3-week interval. Mean differences for the same period varied between 0.1 and 2.9 degrees. The validity of NHO was supported also by a panel investigation. Clinicians as well as auxiliary personnel can be trained to make a critical judgement of the recorded natural head position and correct head orientation, whenever indicated, to enhance the reliability of cephalometric analysis in clinical practice and research.

Adolescent↗

Costs of periodontal and prosthodontic treatment and evaluation of oral health in patients after treatment of advanced periodontal disease.

Retrospective estimations of dental care costs of periodontal and prosthodontic treatment and evaluation of oral health in 37 patients with advanced periodontal disease were carried out. Measures of their subjective evaluation of oral health 7-10 yr after the treatment are presented as a health profile and as indices in single numbers. The relations between oral health as an index and the dimensions in the health profile are analyzed. Dental care costs for treatment in the mandible was SEK 35 550, for the maxilla SEK 45 380 and for both jaws SEK 74 230. After the treatment oral health as well as general health were in excess of 75 on a 0 to 100 scale. Chewing ability, comfort and aesthetics were the variables found to significantly affect the subjective oral health. Oral health in terms of periodontal and prosthodontic conditions was maintained over the observation period.

Adult↗

Evidence for a role of corneodesmosin, a protein which may serve to modify desmosomes during cornification, in stratum corneum cell cohesion and desquamation.

Corneodesmosin, defined as the protein recognized by the monoclonal antibody G36-19, is a recently described late differentiation protein of human cornified epithelium. In the stratum corneum it is localized in the extracellular parts of modified desmosomes (corneodesmosomes) and adjacent parts of the cornified cell envelope. The aim of the present study was to investigate whether corneodesmosin undergoes changes in the stratum corneum which can be related to the cohesive state of the tissue and to desquamation. Extracts of plantar stratum corneum from various tissue levels and tape-stripped non-palmoplantar stratum corneum were analysed by immunoblotting with G36-19. In addition, the fate of corneodesmosin during shedding of surface cells in a recently described in vitro model of desquamation in plantar stratum corneum was investigated and compared with the degradation of the desmosomal protein desmoglein I in this system. The apparent molecular weights of the major G36-19-positive components in plantar stratum corneum ranged between 33 and 48 kDa. The components with the highest molecular weights were predominant in the deepest tissue layers. In the intermediate tissue layers G36-19-positive components of molecular weight 33-36, 39 and 44-48 kDa were found. There seemed to be a further degradation of the 33 to 36-kDa components in the most superficial parts of the tissue. In surface cells dissociated in vivo as well as in vitro no G36-19-positive components with molecular weights above 36 kDa were detected. Results from analyses of nonpalmoplantar stratum corneum suggested that corneodesmosin is degraded in this tissue in a way that may be similar to that in plantar stratum corneum.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Differentiation↗

The gene for diffuse palmoplantar keratoderma of the type found in northern Sweden is localized to chromosome 12q11-q13.

Hereditary palmoplantar keratoderma is characterized by hyperkeratosis of the skin of palms and soles. An autosomal dominant form of diffuse non-epidermolytic palmoplantar keratoderma, frequently complicated by fungal infections, is encountered in northern Sweden with a prevalence of 0.3-0.55%. We have examined two families with this type of palmoplantar keratoderma and localized the causative genetic defect to a 14 cM interval on chromosome 12q11-q13, a region known to contain the keratin type II gene cluster as well as the retinoic acid receptor gamma gene. The palmoplantar keratoderma variant investigated in this study is thus genetically different from epidermolytic palmoplantar keratoderma, which recently has been shown to result from mutations in the gene for the type I keratin 9.

Chromosome Mapping↗

Quantitative evaluation of the soft tissue profile in the planning of orthognathic surgery.

The clinical application of a proportional soft tissue profile analysis based on natural head position is presented. The analysis provides data concerning the morphological basis of facial disharmony in individual cases. The use of this information during treatment planning and evaluation of treatment results after orthognathic surgery is demonstrated in four patients with severe deviation from midnormal profiles.

Adolescent↗

Natural head position as a basis for cephalometric analysis.

In a sample of orthodontic patients (27 boys and 25 girls, 10 to 14 years old), natural head position (NHP) was photographically recorded. A vertical axis was recorded on the photographs with a plumb line and transferred to the lateral head radiographs of the patients. Three cephalometric reference lines (sella-nasion, basion-nasion, and porion-orbitale) were compared with regard to their inclination to the horizontal plane. These angles showed standard deviations of between 4.5 degrees and 5.6 degrees. Reproducibility of NHP, assessed as the error of a single observation, was close to 2 degrees. These findings, in combination with the fact that the NHP represents a realistic appearance of patients, support its use as a basis for cephalometric analysis of dentofacial anomalies. A strong correlation was found between the inclinations of the three cephalometric reference lines to the horizontal plane. The close anatomic relationship between these lines, in combination with the small random movements of the head around NHP, were believed to explain the covariation.

Adolescent↗

A proportional analysis of the soft tissue facial profile in young adults with normal occlusion.

A proportional soft tissue profile analysis is presented, based on natural head position (NHP) and an extracranial vertical reference line through Porion. Twelve linear soft tissue variables and norms for 11 indices expressing vertical and horizontal soft tissue proportions of the face were obtained from lateral skull radiographs of 40 Swedish adults (20 males, and 20 females) with good occlusion. Sexual dimorphism, with larger dimensions in men than in women, was most pronounced in the vertical plane. With regard to facial soft tissue proportions, significant differences between men and women were found only for those indices which involved measurements of lower jaw prominence and facial height. The means and standard deviations for six indices in the female group were compared with corresponding data obtained from the Peck and Peck sample, which had been selected on esthetic grounds. The results showed a close match between the groups. The proportional soft tissue analysis is recommended for the treatment planning of patients scheduled for orthognathic surgery.

Adult↗

A chymotrypsin-like proteinase that may be involved in desquamation in plantar stratum corneum.

We have recently reported that unipolar cell shedding from plantar stratum corneum incubated in vitro, and the associated degradation of the desmosomal protein desmoglein I, are dependent on the activity of a proteinase that can be inhibited by aprotinin, chymostatin and zinc ion. The aim of this work was to find a proteinase in plantar stratum corneum that fulfils the criteria for being the responsible enzyme. Dissociated plantar corneocytes were incubated with the chymotrypsin substrate 3-carbomethoxypropionyl-L-Arg-L-Pro-L-Tyr-p-nitroanilide hydrochloride (S-2586) and H-D-Ile-Pro-Arg-p-nitroanilide dihydrochloride (S-2288), a substrate for a wide range of serine proteinases with arginine specificity. There was a significant rate of hydrolysis of S-2586, but S-2288 was hydrolysed only very slowly. Extraction of dissociated corneocytes with buffers containing KCl or sodium dodecyl sulphate released one major proteinase that could be detected by electrophoresis in polyacrylamide gels with copolymerized casein and subsequent incubations of the gels. Both the caseinolytic activity and the S-2586-hydrolysing activities were inhibited by aprotinin, chymostatin and zinc ion, but not by leupeptin. The S-2586-hydrolysing activity was also inhibited by soybean trypsin inhibitor and phenylmethylsulphonyl fluoride. Both activities were optimal at pH 7-8 but were also significant at pH 5.5. On gel exclusion chromatography, the S-2586-hydrolysing and caseinolytic activities were eluted with an apparent molecular weight of around 18 kDa. When analyzed by electrophoresis in the presence of sodium dodecyl sulphate under non-reducing conditions the caseinolytic enzyme had an apparent molecular weight of around 25 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)

Aprotinin↗

A comparison between estimated and registered natural head posture.

Using tracings of facial profiles, four observers made two independent, subjective estimations of natural head posture (NHP) in 28 adults. The results of these estimations were compared with recordings of NHP obtained through photographic registration of the same subjects. Only minor average differences (between 0 and 1.4 degrees) were found between the two methods. The differences between estimated and registered head posture found at the first and second observation, were positively correlated for both intra- and inter-observer registrations (r = 0.59-0.80 and r = 0.50-0.71, respectively). The inclination of the basion-nasion line was measured; first, in relation to the photographically registered horizontal line and, secondly, in relation to the horizontal line derived from the estimation of NHP. Both methods of measurement gave similar mean values and standard deviations. A panel comprising 18 persons was asked to compare the head orientations of two subjects in whom a marked difference between estimated and registered NHP had been recorded. In the majority of these comparisons, the profiles orientated according to the subjective estimation were judged to have a more 'natural posture' than those orientated by the photographic method. This unexpected finding is discussed.

Adult↗