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Biomedical subjects

B Liedberg

Publications and source records attributed to B Liedberg.

11 recordsLinked to original sources
PubMed1995

Oral bolus kneading and shaping measured with chewing gum.

A masticatory test using two-colored chewing gum is presented and analyzed. Two separate parameters of chewing were studied on the same chewing gum bolus after 10 strokes of oral preparation, color mixing, and bolus shaping. The two parameters were evaluated in indices 1-5. A test series should preferably contain three chewing gums, and color mixing can be evaluated on six sides and shape-indexed for each bolus. The medians characterize the subjects' masticatory ability. Color mixing may relate, for example, to ensalivation of the food during chewing, and bolus shape may relate to preparation into a form suitable for swallowing. The tests were used on test subjects with different dental and denture status. Significant differences in both color mixing and shape indices were found between groups with different status. The method is discussed in relation to earlier types of tests, e.g., the comminution test mostly used hitherto.

Adult↗
PubMed1995

Mastication with and without removable partial dentures: an intraindividual study.

The chewing of 22 subjects, with a total of 27 removable partial dentures (RPD) that had been used for more than 6 months, was analyzed by four different methods. The study design was an intraindividual comparison of chewing, with and without the RPDs. Chewing tests were a color mixture of two-colored gums, chewing gum bolus shaping, comminution of Optosil silicone tablets, and number of chewing strokes to first swallow of an almond. The participants were also asked some standardized questions about their eating, biting, and chewing capacity. There was no significant difference in efficiency as measured by chewing gum color mixing, chewing gum shape, and pulverization of Optosil between chewing with and without the RPDs. Significantly more strokes were needed to swallow an almond without than with the RPD in place. With their RPDs in place, all subjects could chew a sandwich and an apple, and all but one could chew whole meat. The study shows that the chewing process should preferably not be analyzed by one method only.

Adult↗
PubMed1995

Biosensing with surface plasmon resonance--how it all started.

A subjective description is given of how the development of surface plasmon resonance for immunosensing began. The main differences between the initial experiments and a commercially available instrumentation are pointed out. For the practical use of surface oriented methods for biosensing it is noted that the arrangements around the optical system itself, such as the sensing chip or sample cell, are most important. It is concluded that the instrumentation developed can be used not only for immunosensing but also for "real time biospecific interaction analysis" in general. It is pointed out that the use of surface plasmon resonance for detection is only one possibility and that many new (optical) methods for real time biospecific interaction analysis have been and will be developed.

Biosensing Techniques↗
PubMed1994

Social network, social support and dental status in elderly Swedish men.

The objective of this study was to investigate whether there were associations between different aspects of social network and social support and dental status. The study sample (n = 621) comprised a random half of all male residents in Malmö, Sweden, born in 1914. Five hundred (80.5%) participated. Eight conceptually different aspects of social networks and social support were measured, and all men were clinically examined regarding number of teeth, prevalence of removable dentures, fixed bridges and anterior open tooth spaces. We found that some aspects of dental status were associated with social class, while others were associated with different aspects of social network and social support. Prevalence of complete dentures and fixed bridges was strongly associated with social class, a low number of functioning teeth was associated with both low social class belonging and an insufficient social network and social support, while anterior open tooth spaces were associated mostly with an insufficient social network and social support. This study shows that there are significant associations between some aspects of dental status and the social network and social support of the individual, while other aspects of dental status are associated with social class, which from a psychosocial perspective contribute to a deeper understanding of the backgrounds of dental status.

Aged↗
PubMed1991

Masticatory ability in experimentally induced xerostomia.

The masticatory ability of 15 nondysphagic volunteers with complete natural dentition was tested using different chewing parameters including preparation of a two-color plastic chewing gum (bolus shape, and color mixture), particle reduction of a piece of silicone, and number of strokes before swallow of almonds. The tests were performed under conditions of normal salivation and experimental oral dryness caused by intramuscular injection of methylscopolamine. The chewing gum tests as well as the silicone particle reduction tests were not influenced by lack of salivation. The number of chewing strokes prior to the initiation of swallowing of almonds was significantly increased. Oral dryness seems to cause accumulation of particles in the oral cavity from friable food and the particulate material is not transported posteriorly into a "ready-to-swallow" positioning. The absorption of saliva by dry oral content such as an almond further impaired oral manipulation of food.

Adult↗
PubMed1991

Chewing and the dimension of the pharyngoesophageal segment.

Masticatory efficiency was evaluated in 21 adults for four chewing parameters: mixing of a color-patterned chewing gum mass, shaping of a chewing gum mass, particle reduction of a silicone tablet, and number of chewing strokes before the first swallow of an almond. The results of these tests were correlated with the dimension of the pharyngoesophageal (PE) segment during swallow of liquid barium and solid meat. The transverse width of the PE segment during swallow of liquid barium correlated significantly with the chewing parameters. The sagittal width of the PE segment during swallow of liquid barium correlated only weakly with the chewing parameters. The PE segment dimension during swallow of a solid meat bolus did not correlate with the chewing parameters. The results suggest that there is feedback during chewing and swallowing between the PE segment and the oral cavity.

Adult↗
PubMed1991

Teeth, tooth spaces, and prosthetic appliances in elderly men in Malmö, Sweden.

A group of 483 men, all of whom were 68 or 69 yr old and had lived for a long time in the city of Malmö were examined with regard to number of teeth present, removable dentures, fixed bridges, and tooth spaces. 76.4% had one or more natural teeth remaining, 59.2% had removable dentures, and 0.2% were edentulous and without dentures. The mean number of teeth present in a fixed dentition calculated on dentate subjects was 16.21 +/- 8.02, including teeth replaced by pontics and 15.0 +/- 7.44 when natural teeth only were recorded. The number of bridges was high, 28.8% of natural dentate persons having bridgework. This cohort had fewer remaining teeth than in similar groups in other areas of Sweden, but more fixed bridges. 19.5% had open tooth spaces corresponding to one or more teeth in the visible parts of the dental arches. The availability of dentistry has been extremely good in Malmö and financial support for all types of dental care has been provided for all inhabitants since 1974. In spite of this, a low number of remaining teeth and many untreated tooth spaces in visible part of the dental arches were found, though on the other hand much fixed bridgework was found. It appears from the present study that the population tends to polarize into two groups, namely one group which takes advantage of the dental services and one which does not.

Aged↗
PubMed1984

Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRAS) of fibrinogen adsorbed on metal and metal oxide surfaces.

We have investigated the possibilities of using Infrared Reflection Absorption Spectroscopy in the study of the interaction of proteins with metal surfaces. Structural information can be obtained since the infrared radiation at the metal surface interacts only with dipole transition moments perpendicular to the metal surface. Fibrinogen spontaneously adsorbed from solution onto gold, titanium and aluminum was used as model systems. The infrared studies were carried out on dried protein films. The amide I bands of fibrinogen adsorbed on the metal surfaces shift towards higher frequencies (ca. 20 cm-1) relative to the same band in buffer solution. The magnitude of these shifts indicates that conformational change of the protein occurs upon adsorption on metal surfaces. The change in conformation of the fibrinogen also can partly be due to one week of drying at room temperature. The amide I and amide II bands show a slightly different behaviour in terms of frequency and intensity for each metal-protein system studied. The side chains appeared to be more substrate sensitive than the peptide group. Orientational effects were observed for a number of side-chain related groups.

Adsorption↗
PubMedDate not supplied

Barium and meat. A comparison between pharyngeal swallow of fluid and solid boluses.

The influence of bolus consistency on pharyngeal swallow was radiologically studied in 24 individuals by comparing liquid barium and solid meat after chewing. Pharyngeal function was apparently performed synchronously and symmetrically on both boluses. No definite conclusion about the influence on epiglottic mobility, closure of the laryngeal vestibule and relaxation of the cricopharyngeal muscle could be drawn from this study. There was no difference in the elevation of the pharynx and larynx. The transit time for a solid bolus was shorter compared with that of a fluid bolus. The transit time for the apex of the bolus was shorter than for the tail. A more marked elevation of the pharynx and larynx was followed by a shorter transit time. The width of the pharyngo-esophageal segment was larger in the transverse than in the sagittal diameter during the passage of the bolus and larger on solid compared with fluid swallow. Our results reflect the ability of pharyngeal swallow to be executed with precision and with few alterations due to variable bolus consistency.

Adult↗