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Biomedical subjects

A Sundby

Publications and source records attributed to A Sundby.

At least 19 recordsLinked to original sources
PubMed2003

Oral health status in relation to ethnicity of children in the Municipality of Copenhagen, Denmark.

UNLABELLED: Approximately 25% of children under the age of 18 in the Municipality of Copenhagen have a non-Danish ethnic background, and it is suspected that there may be major inequalities in oral health as a result. OBJECTIVES: The objectives of this study were to describe the occurrence of dental caries in different ethnic minorities, and to analyse whether the dental caries experience of the children may be affected by cultural and behavioural differences. MATERIALS AND METHODS: The study was conducted in Copenhagen as a cross-sectional investigation of 794 children, aged 3 and 5 years old (preschool), 7 years old (Grade 1) and 15 years old (Grade 9). Children of Danish, Turkish, Pakistani, Albanian, Somali and Arabian backgrounds were selected by convenience sampling. Epidemiological data were retrieved from the Danish Recording System for the Public Dental Health Services (SCOR) and sociological data were collected by postal questionnaires. RESULTS: Marked differences in dental caries prevalence were observed when different ethnic minorities were compared to Danish children. These were most prominent for the primary dentition. At age 7, 53% of the Danish and 84% of the Albanian children were affected by dental caries, the mean caries experience was 3.5 dmfs (decayed, missed and filled surfaces) and 13.8 dmfs, respectively. Caries in incisors and/or smooth surfaces was observed in 10% of the Danish children and 48% of the Albanian children. There were cultural differences in dental attendance and self-care practices of children and parents. These socio-behavioural factors may help to explain the differences in dental caries prevalence and severity. CONCLUSIONS: Development of appropriate oral health promotion strategies is urgently needed to improve oral health behaviour and attitudes of parents and children of ethnic minorities. Preventive programs should be organized at local community level in close collaboration with key persons of ethnic minority societies.

Adolescent↗
PubMed1994

Extended high-frequency audiometry. Air- and bone-conduction thresholds, age and gender variations.

Air-conduction and bone-conduction thresholds have both been determined in the conventional audiometric frequency ranges and in the extended high frequencies through respectively 18 and 16 kHz for otologically healthy subjects in different age groups covering the age span 8-14 years through the eighth decade. Subjects younger than 30 years had conventional frequency air-conduction thresholds < or = 10 dB HL, whereas the corresponding thresholds of older subjects were within 0.1 and 0.9 percentiles of ISO 7029 (1984). Age- and gender-specific thresholds, medians and ranges, are presented for bone conduction in the extended high frequencies. Thresholds increase with both age and frequency in the range 8-16 kHz, and there is a largely non-significant tendency for thresholds to be higher in males. Threshold deterioration at the highest frequencies is already present at age 18-24 years compared with the youngest (8-14 year) age group.

Acoustic Stimulation↗
PubMed1992

High-frequency audiometry. Masking of air- and bone-conduction signals.

Interaural attenuation has been investigated for both air-conduction and bone-conduction signals in the frequency ranges 0.25-18 and 0.25-16 kHz respectively. Ear canal occlusion is recommended when using the Koss HV/1A earphone for BC masking, as acoustic transmission occurs through the headset in the high-frequency range. Minimum masking levels for 1/3-octave filtered white noise were established for bone-conduction signals in the frequency range 8-16 kHz. Central masking of bone-conduction signals proved to be of the same order of magnitude in the conventional- and high-frequency ranges, while the cross-masking level was approximately 10-15 dB lower above 6 kHz. Recommendations are made for a masking procedure in the high frequency range.

Acoustic Stimulation↗
PubMed1991

Insulin and glucagon family peptides in relation to activities of hepatic hexokinase and other enzymes in fed and starved Atlantic salmon (Salmo salar) and cod (Gadus morhua).

1. Plasma levels of insulin, glucagon, and glucagon-like peptide (Glp) were all reduced by starvation of salmon and cod. In the salmon the drop in Glp was larger than in insulin and glucagon. 2. After starvation the activity of hexokinase (EC 2.7.1.1) was increased in salmon liver, but decreased in cod liver. The salmon hepatic hexokinase activity was inversely correlated with the Glp/insulin ratio. 3. Activities of hepatic glycogen phosphorylase (EC 2.4.1.1) and phosphofructokinase (EC 2.7.1.11) were increased in starved as compared to fed salmon. In cod, starvation resulted in decreased or unchanged activity of phosphorylase. This discrepancy may be related to different degrees of environmental and handling stress. 4. Intraperitoneal injection of human insulin in salmon gave increased hepatic phosphorylase and hexokinase activities and reduced plasma levels of glucagon, Glp and endogenous fish insulin at sampling after 30 hr. 5. No differences in hepatic hexokinase activities or plasma hormone levels were observed between cod fed low and high carbohydrate diets. Apparently, regulation of glucose phosphorylation by dietary carbohydrate does not occur.

Animals↗
PubMed1991

High-frequency audiometry. Response characteristics of the KH70 vibrator.

Various response characteristics of the Präcitronic KH70 bone vibrator have been investigated in the frequency range 0.25 through 16 kHz. Masked threshold reproducibility is satisfactory throughout the frequency range. An occlusion effect is present only at frequencies at and below 1 kHz. Stimulus perception lateralizes to the occluded ear through 1 kHz and less consistently at successively higher frequencies. The KH70 does not satisfy the IEC 645 (1979) criterion for acoustic radiation for frequencies below 6 kHz, especially at the intermediate frequencies of 0.5, 1 and 2 kHz. With the restrictions inherent in the occlusion effect, this does not, however, interfere with threshold determination. The vibrator would thus seem suitable for clinical use through 16 kHz.

Adult↗
PubMed1984

Testicular gonadotropin receptors, testicular testosterone, dihydrotestosterone and androstenedione in the developing bull.

The testis homogenate from Red bull (3-17 months of age) show specific binding of hLH and hFSH with Kd of 1.3 +/- 0.1 X 10(-10)M and 1.5 +/- 0.1 X 10(-9)M, respectively. Prepubertal bulls (3-5 3/4 months) exhibit the highest binding capacity of both LH and FSH, revealing the fact that LH and FSH receptors are present in high concentrations prior to the first rise in plasma T. The testicular T concentration was significantly higher in the four prepubertal bulls than in the four older animals in spite of the fact that circulating T is lower before puberty. Thus, local androgen effects within the testis may occur before peripheral androgenization. The prepubertal bull Leydig cell also displayed steroidogenic capacity. The ratio of biologically active (testosterone, dihydrotestosterone) to inactive androgens (androstenedione) increased as the animals approached puberty. Such qualitative changes in steroid production may be one of the factors responsible for peripheral androgenization.

Androgens↗
PubMed1983

Developmental pattern and sensitivity to down-regulation of testicular LH receptors in the pig.

Testicular receptors for luteinizing hormone (LH) were quantified in 40 pigs between the day of birth and 22 weeks of age. The highest specific binding capacity (fmol hLH bound/mg protein) occurred at about 2--3 weeks of age which coincides with the age when the relative volume of Leydig cells is at a maximum. Significantly lower binding capacity was observed at 7 weeks of age which is the time of maximum Leydig cell regression. hCG was injected intramuscularly to immature (3000 IU, 22 days old) and adult boars (10 000 IU, 30--40 weeks old). Twentyfour h after injection the numbers of available LH receptors were reduced to 6 and 18% of control values, respectively. At this time occupied receptors were at a maximum (90% and 67% of controls, respectively). The total number of LH receptors (available + occupied) was increased 1 h after injection after which a gradual decrease was observed. Three days after hCG administration the total receptor quantities were at a minimum in both immature and adult pigs (59% and 31% of controls, respectively) and returned to control levels 5--7 days after treatment. Thus, pig LH receptors appear to be subjected both 'positive' and 'negative' regulation as previously described in the rat.

Aging↗
PubMed1983

Relationship between growth rate in bulls and human chorionic gonadotropin-induced plasma testosterone concentrations.

In the selection of bulls for breeding purposes growth rate is an important characteristic. In this study 411 bulls, 5 to 11 mo of age were subjected to a human chorionic gonadotropin (hCG) stimulation test. Plasma testosterone 7 h postinjection of hCG was related to monthly weight gain in the month of blood sampling and to daily gain from 3 to 11 mo of age. The bulls were divided into two groups according to plasma testosterone concentrations; those with values above and those with values below the average for each age group. Over all ages (5 to 11 mo), the bulls in the high testosterone group had higher monthly (P less than .001) and daily (P less than .025) weight gain than those in the low testosterone group. However, when split into two groups according to age (5 to 7 and 8 to 11 mo), only the older animals showed the relationship described above. The results indicate that determination of plasma testosterone might supplement other criteria in the selection of breeding bulls for beef production. Eight to 11 mo of age, when differences between high and low levels of testosterone were greatest, would appear to be the most suitable period for sampling.

Animals↗
PubMed1982

Auditory brainstem responses (ABR) in high-risk neonates.

In the present study, auditory brainstem responses (ABR) were recorded in 60 high-risk neonates in the intensive care unit selected by the following criteria: Birth-weight less than 2000 g, hyperbilirubinemia requiring phototherapy or exchange transfusion, idiopathic respiratory distress syndrome, artificial ventilation, asphyxia, sepsis or meningitis, intracranial haemorrhage, neurological symptoms and potential ototoxic medication (aminoglycoides, furosemide). The infants tested ranged in gestational age from 27-44 weeks. The ABR testing was performed in a sound-proof room using the Madsen (ERA-74) equipment. Four infants did not reveal responses to 70 dB HL ("nonresponders"), and the total of 10 neonates (16.6%) had abnormal ABR-tests, when the physiological changes related to gestational age and conceptional age (gestational age plus the age after birth) were taken into account. The 10 neonates with abnormal tests were reexamined after discharge, and in six there were no improvement of threshold sensitivity. three of the "nonresponders" were retested several times within the two years after birth (one died at age 18 months of pertussis), and none of them revealed ABR at stimulus intensity of 70 dB HL. They all attend an audiological training program started at age of six months as a consequence of the early diagnosis of impaired auditory function. It is our opinion that a routine ABR-evaluation should be performed on high risk neonates (criteria mentioned above) in the newborn intensive care unit. Retesting of infants with abnormal responses within three months, and several times within the next two years if abnormal responses persist, is important. Transient impairment of auditory functions is not uncommon in these infants. However, the children with persisting hearing impairment should be discovered early to attend an early audiological training program.

Age Factors↗
PubMed1982

Particulate and solubilized LH receptor in the pig and bull testis.

Particulate and Triton X-100 solubilized receptors for luteinizing hormone (LH) in the pig and bull testis were studied. In some of the experiments tissue from the rat testis was included for comparison. LH receptors in the bull and pig revealed very similar association and dissociation kinetics, affinity (Kd = 1.2-1.8 x 10(-10) M), stability and physicochemical properties. Binding capacity was higher in the pig (73 fmol/mg protein) than in the rat (33 fmol/mg protein) and bull (17 fmol/mg protein). Hormone binding stabilized the receptor against thermal denaturation and temperature stability decreased upon solubilization. It is concluded that the properties of the testicular LH receptor of the pig and bull are very similar to those previously described from the rat.

Animals↗
PubMed1981

Effect of hemicastration on the level of testicular steroids and growth in bulls and boars.

Ten, bull calves of the Norwegian Red breed were hemicastrated at the age of 1 1 2 -3 months . Ten, normal bull calves of similar age served as controls. No significant differences were found in plasma testosterone levels or in weight between the two groups during the ensuing seven-month test period. Eight, male pigs were hemicastrated at 1-2 months of age. Eight, normal male pigs served as controls. Plasma testosterone, androstenone, and body weight were measured fortnightly in all pigs until the age of 6-7 months. Androstenone in adipose tissue was measured from 4-5 months of age. No significant differences were found between normal and hemicastrated animals in any monthly interval. However, when combining the measurement at 5-6 and 6-7 months of age for plasma testosterone and 5alpha-androstenone and 5alpha-androstenone in fat, the normal pigs had significantly higher values than the hemicastrates (p<0.05). The weight of the single testis from the hemicastrated pigs at slaughter nearly equalled the combined weight of both testes from the controls. Thus, hemicastration did not appear to have any significant effect on the level of testicular steroids in plasma in bulls or growth rate in bulls and boars, but did have a slight effect on testicular steroids in plasma in pigs at 5-7 months of age.

Journal Article↗
PubMed1981

Fine structure and FSH binding of Sertoli cells in the blue fox (Alopex lagopus) in different stages of reproductive activity.

A clearly different Sertoli cell morphology was found in the immature blue fox and in the adults in and out of season. Immature cells had small, basally, located nuclei rich in peripheral heterochromatin, and few cytoplasmic organelles. Sertoli cells from adults in season had basally located, large, convoluted nuclei with homogenous nucleoplasma and prominent nucleoli. The basal and intermediate parts of the cytoplasm contained an extensively developed ER, numerous mitochondria, free ribosomes, lipid droplets and residual bodies, while the apical cytoplasm showed few distinct structures. In Sertoli cells from adults out of season the nuclei were dislocated towards the lumen, and apart from numerous dilated cisternae of ER, there were generally fewer organelles, but more glycogen particles. A marked rise in FSH binding was found towards the breeding season.

Aging↗
PubMed1980

Plasma concentration of testosterone in young bulls in relation to age, rate of weight gain and stimulation with human chorionic gonadotrophin.

In 86 bulls ranging in age between 3 and 11 months, the maximal plasma testosterone concentration (n = 7 as well as the mean concentration (n = 7), same samples) were found to increase with age to peak values at 7-8 months with a subsequent decrease. The multiple correlation coefficient for monthly gain as a function of testosterone concentraton and age was 0.85 (P < 0.001), for monthly gain as a function of age 0.84 (P < 0.001) and for monthly gain as a function of testosterone concentration 0.44 (P < 0.001). The deviation in levels of measured plasma testosterone from the curve expressed by multiple regressiuon analyses of testosterone concentration as a function of age was correlated with the average daily weight gain during the testing period of 9 months and found to be not significant (r = 0.21). The difference between concentrations of plasma testosterone after stimulation with human chorionic gonadotrophin (HCG) and the spontaneous maximal concentration of this hormone was not signifiant. High correlation coefficients were found between maximal (r = 0.8) and mean (r = 0.6) concentratiaons of plasma testosterone before and after an injection of HCG (P < 0.001).

Aging↗