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Biomedical subjects

B Melsen

Publications and source records attributed to B Melsen.

At least 163 records · Page 9Linked to original sources
PubMed1978

Histomorphometric analysis of normal bone from the iliac crest.

Bone specimens from a standardized area of the iliac crest were obtained at autopsy in 105 individuals after sudden unexpected death and at biopsy in 30 living volunteers. Seven micron thick sections of the plastic embedded undecalcified material were produced and stained. The amount of cancellous and cortical bone and the parameters attached to description of bone remodelling were determined by point counting and simple measurements, in order to establish normal mean values and range in a Danish population. A decrease in the amount of bone, trabecular as well as cortical, was found with increasing age in both males and females. The extent, volume and width of osteoid seams and the osteoclastic resorption were found to be age-independent. The osteoclastic resorption in cortical bone in males decreased, however, with increasing age. The reported values are of the greatest importance for the use of histomorphometric analysis of bone biopsies as a diagnostic tool in metabolic bone diseases. It is stressed, however, that supplementary information of the dynamic aspects of the bone remodelling would be necessary for the understanding of the pathogenesis of bone changes. Such information might be obtained by using tetracyline double labelling.

Adolescent↗
PubMed1978

Is sulphated blood-group substance in pancreas a factor in cystic fibrosis?

The present study showed that the pancreas of two monkey species contained sulphated blood-group substance. Such strongly anionic molecules are known to bind calcium, and their solutions form gels in the presence of cations. It is suggested that such a mechanism may be involved in cystic fibrosis.

Animals↗
PubMed1977

Histological analysis of the postnatal development of the nasal septum.

The importance of the growth in the nasal septum for the development of the facial skeleton has often been stressed. An increase in dimension is well-known from radiographs. It was the purpose of the present study to describe the normal pattern of the growth sites of the nasal septum according to age and sex by histological and microradiographical examination of human autopsy material. The nasal septum was removed from 66 boys and 57 girls who had died in accidents. Decalcified sections for conventional histology as well as undecalcified sections for microradiography were prepared. The superior surface and posterior margin of the vomer as well as the vomeroethmoidal and the vomeromaxillary sutures were studied. It was obvious that increase in size of the vomer could mainly be ascribed to apposition on the superior surface and the posterior margin. This was seen until adult age. After the ethmoid bone was ossified, the connection between the vomer and the perpendicular plate of the ethmoid bone was a slightly sinuous suture in which growth occurred until puberty. The growth pattern implied that a forward, downward sliding of the vomer must take place in relation to the ethmoid bone and the cartilaginous septum. Frontal sections revealed that, after the establishment of the suture between the vomer and the perpendicular plate of the ethmoid, a cartilage island was embedded in the vomer surrounded by thin, fenestrated cortical bone blades. This cartilage still persisted in specimens from adults. There is, on the basis of the present findings, no reason to believe that the septal cartilage plays a major role in the forward, downward growth of the maxillary complex in homo.

Adolescent↗
PubMed1977

The effect of methylazoxymethanol on growth of the spheno-occipital synchondrosis in rats.

Methylazoxymethanol (MAM) causes a reduced development of cerebellum and medulla oblongata in rats. To study the effect of external factors on growth of the spheno-occipital synchondrosis, four litters of rats each of five animals were treated with MAM within 12 h after birth and sacrificed after 30 days. A similar number od control rats were sacrificed at the time when their skull length was equal to that of the experimental rats. Microradiographical and histological investigations showed that the cranial base lordosis was more pronounced in the MAM rats than in the controls, and that the width of the spheno-occipital synchondrosis was reduced mainly due to reduction in the central zone.

Animals↗
PubMed1976

The effect of professional toothcleansing on gingivitis and dental caries in children after 1 year.

The purpose of this study was to determine the effects of professional mechanical toothcleansing on plaque, gingivitis, and dental caries in young children with a high caries experience. Seventy-eight children, 7 years of age, were stratified according to presence or absence of smooth surface lesions on the permanent teeth and subsequently randomly assigned to an experimental group and a control group. The experimental group was given a thorough mechanical toothcleansing every 2 weeks. After 12 months a statistically significant difference in plaque accumulation and a minor difference in level of gingival inflammation could be demonstrated between the two groups. The incidence of dental caries in permanent teeth present at both examinations was 70% lower in the experimental group. The effect on permanent teeth erupting during the study and on primary teeth present at both examinations was not statistically significant.

Child↗
PubMed1976

The relation between densitometric and quantitative histological analysis of bone specimens from the iliac crest.

Roentgendensitometric measurements were correlated with quantitative histological analysis of cortical and cancellous bone from a standard anatomical site on the iliac crest. The point-count method was used to quantitate spongy bone in 8 mu thick sections. Measurements of the thickness of the cortices were made with a micrometric eyepiece. The reproducibility of the method for the roentgendensitometric analysis was found to be about 1 per cent of the mean for all variables. The correlation between roentgendensitometric and histological analysis was found to be low (r=0.44) and could be ascribed mainly to variation in the thickness of the cortices which again was only slightly correlated with the percentage of spongy bone (r=0.39). Both the determination of the amount of bone mineral and of bone by quantitative histometric analysis are required for diagnosis of skeletal system disorders.

Absorptiometry, Photon↗
PubMed1975

Palatal growth studied on human autopsy material. A histologic microradiographic study.

The postnatal development of the hard palate was studied by conventional histologic and microradiographic means on autopsy material from thirty-three boys and twenty-seven girls aged 0 to 18 years. The findings indicated thet growth in length of the hard palate until the age of 13 to 15 was due to growth in the transverse suture and to apposition on the posterior margin of the palate. After this age the sutural growth was found to cease, whereas the apposition seemed to continue for some years. During the postnatal development the morphology of the transverse suture changed. At birth the suture was broad and slightly sinuous; later it developed into a typical squamous suture, the palatine part covering the maxillary part. During puberty the course of the suture was again slightly sinuous. The importance of this change for the vertical growth of the hard palate was discusses. It was pointed out that the lowering of the anterior part of the palate. The transverse growth of the midpalatal suture continued up to tha age of 16 in girls and 18 in boys. On the basis of morphology, the development of the median suture could be divided into three stages. In the first stage the suture was short, broad, and Y shaped; in the second the course was more sinuous; and in the third interdigitation was so heavy that a separation of the two halves of the maxilla would not be possible without fracturing the interdigitated processes.

Adolescent↗
PubMed1975

Application of chlorhexidine by oral irrigation systems.

Low concentrations of chlorhexidine (0.006%) were found to inhibit plaque formation when 750 ml was applied twice daily by oral irrigation systems. The procedure took 1-2 min and may be a convenient method of maintaining oral hygiene in patients in whom normal mechanical cleansing is difficult.

Biguanides↗