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Biomedical subjects

M Vestergaard

Publications and source records attributed to M Vestergaard.

32 records · Page 2Linked to original sources
PubMed1999

Duration of breastfeeding and developmental milestones during the latter half of infancy.

Several studies have suggested that breastfeeding has a long-term influence on brain development. However, interpretation of these findings is complicated by the presence of many potential confounding factors. Only a few studies have examined infants before 1 y of age, although very early assessment might reduce the role of environmental influence. We investigated the association between exclusive breastfeeding and three developmental milestones related to general and fine motor skills and early language development at the age of 8 mo. We followed 1656 healthy, singleton, term infants, with a birthweight of at least 2500 g, born between May 1991 and February 1992 in Aarhus, Denmark. Information was collected at 16 wk gestation, at delivery and when the infant was 8 mo old. Motor skills were evaluated by measurement of crawling and pincer grip. Early language development was defined as the ability to babble in polysyllables. The proportion of infants who mastered the specific milestones increased consistently with increasing duration of breastfeeding. The relative risk for the highest versus the lowest breastfeeding category was 1.3 (95% CI: 1.0-1.6) for crawling, 1.2 (95% CI: 1.1-1.3) for pincer grip and 1.5 (95% Cl: 1.3-1.8) for polysyllable babbling. Little change was found after adjustment for confounding. In conclusion, our data support the hypothesis that breastfeeding benefits neurodevelopment.

Breast Feeding↗
PubMed1999

Contribution of insulin-like growth factor (IGF)-I and IGF-binding protein-3 to mitogenic activity in bovine mammary extracts and serum.

Peripubertal development of the mammary gland is probably mediated by locally produced growth factors acting in concert with circulating mitogens. Our objective was to investigate the effect of recombinant human insulin-like growth factor-binding protein-3 (rhIGFBP-3) or insulin-like growth factor-I (IGF-I) antibodies on the IGF-I-related mitogenic activity of bovine serum and of mammary tissue extracts in primary mammary epithelial cell cultures. Cells were obtained from prepubertal female calf mammary tissue and cultured in three-dimensional collagen gels. An aqueous mammary parenchymal tissue extract (pooled from 20 prepubertal heifers) or serum (pooled from 3 heifers) at a concentration of 5% was added to the medium containing either rhIGFBP-3 or monoclonal or polyclonal antibodies to human IGF-I. Cell proliferation was evaluated using [methyl-3H]thymidine incorporation as a measure of DNA synthesis. Addition of mammary extracts stimulated DNA synthesis 545% compared with basal medium. Addition of serum stimulated DNA synthesis by 28%. Mitogenic activity of serum and added IGF-I was abolished by addition of rhIGFBP-3 in equimolar concentrations with IGF-I. For mammary extracts, mitogenic activity was inhibited by 35%, 50%, and 82% by the addition of rhIGFBP-3 at, respectively, 1, 2 and 4 times the molar IGF-I concentration in the extract. Addition of rhIGFBP-3 to basal medium reduced DNA synthesis by 26%, whereas IGF-I antibodies had no consistent effect. These results indicate that circulating and mammary-synthesized IGF-I and IGFBPs probably play a critical role in prepubertal development of the bovine mammary gland.

Analysis of Variance↗
PubMed1995

Effects of growth hormone and ovariectomy on performance, serum hormones, insulin-like growth factor-binding proteins, and muscle fiber properties of prepubertal Friesian heifers.

Sixteen prepubertal Friesian heifers were used to examine the effect of bovine growth hormone (GH) and ovariectomy (OVX) at 2.5 mo of age (2 x 2 factorial design) on growth, carcass quality, and fiber types, capillarization, and metabolic potentials of the longissimus muscle, and serum concentrations of estradiol-17beta (E2beta), insulin, GH, IGF-I, and IGF-binding proteins (IGFBP). Treatment with GH (15 mg/d) started at 147 +/- 3 kg BW and lasted for 15 wk. Heifers were fed a mixed roughage-based diet. Growth hormone increased ADG (P < .001), improved gain:feed (P < .007), and had a small but positive influence on lean accretion. Growth hormone reduced fat thickness (P < .009), carcass fat trim (P < .009) and i.m. fat (P < .09). Ovariectomy did not affect performance but increased dressing percentage (P < .03), full rib weight (P < .003), and fat thickness (P < .04). Ovariectomy reduced E2beta (P < .001) and insulin (P < .02), and increased the 32-kDa IGFBP (IGFBP-2) (P < .09). Growth hormone treatment increased GH, IGF-I, the 28-kDa IGFBP, and the 40- to 43-kDa IGFBP (IGFBP-3) (P < .004 or P < .001). Neither GH nor ovariectomy affected the proportion and relative area of the individual muscle fiber types, but GH tended to increase type I fiber area (P < .10). Number of capillaries per fiber increased in OVX GH-treated heifers (GH x OVX interaction, P < .02). Activities of citrate synthetase were higher in GH-treated (P < .05) and OVX (P < .02) heifers, indicating increased oxidative capacity of the longissimus muscle. The effects of GH on performance and carcass fattening were in accordance with the observed hormonal changes. When slaughter occurs before puberty, ovariectomy has no effect on performance, only few effects on carcass quality, and small effects on hormone concentrations.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1994

The effect of cimaterol on muscle fiber characteristics, capillary supply, and metabolic potentials of longissimus and semitendinosus muscles from young Friesian bulls.

The objective of this study was to determine the effect of the beta-adrenergic agonist cimaterol (CIM) on fiber characteristics, capillary supply, and metabolic enzyme activities in muscles of young Friesian bulls. Four pairs of monozygotic twins in each of three live weight groups (WG) were used (initial average live weight [LW]: 162, 299, and 407 kg, respectively). Within each pair, one twin was fed .06 mg of CIM.kg LW-1.d-1 for 90 d. The other twin served as control (C). Needle biopsies were obtained from the longissimus (LM) and semitendinosus (ST) muscles at d 82 to 84 of treatment, and muscle fibers were identified as slow-twitch (Type I) or fast-twitch (Type IIA or Type IIB) by the myosin ATPase stain. In LM, the proportion of Type I (C: 24.0%, CIM: 20.4%; P < .07) and Type IIA fibers (C: 24.2%, CIM: 8.6%; P < .001) decreased, whereas the proportion of Type IIB fibers increased (C: 51.7%, CIM: 71.1%; P < .001). Cimaterol increased the cross-sectional area of Type I (P < .02) and Type IIB fibers (P < .001), with no change in Type IIA fibers. Overall, the mean fiber area increased (C: 2,363 microns 2, CIM: 3,934 microns 2; P < .001). The number of capillaries per fiber did not change, but the number of capillaries per square millimeter decreased (P < .001) after CIM treatment. Cimaterol changed metabolic enzyme activities toward lower oxidative capacity of the muscle (lactate dehydrogenase: +22%, hydroxyacyl-CoA dehydrogenase: -33%, and citrate synthetase: -34%; all P < .001) and reduced the glycogen content by 25% (P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1991

Tumour necrosis factor alpha and interleukin-2 in plasma from rheumatoid arthritis patients in relation to disease activity.

Tumour necrosis factor alpha (TNF alpha) and interleukin-2 (IL-2) are potential immunological mediators of pathogenetic changes in rheumatoid arthritis. We measured the concentrations of TNF alpha and IL-2 in plasma from 2 groups of patients suffering from rheumatoid arthritis (RA). One group had high and one had low disease activity. In addition, in connection with steroid treatment in the high disease activity group, TNF alpha was significantly increased in plasma from RA patients with high disease activity compared with those of low disease activity (p = 0.0009). Furthermore, TNF alpha decreased significantly in relation to steroid medication, parallel to clinical improvement (p = 0.016). All IL-2 concentration measurements were within the estimated normal range. The increased TNF alpha plasma levels in patients with rheumatoid arthritis with high disease activity, might result from activated white mononuclear cells in the inflamed joints. This might, in part, support the theory that TNF alpha is a possible mediator of pathogenetic changes known to occur in rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1989

Changes in PMN leukocyte migration activity and complement C3d levels in RA patients with high disease activity during steroid treatment.

We have investigated chemotaxis of polymorphonuclear granulocytes (PMN) from 7 well characterized RA patients with intense disease activity, before and after steroid treatment. Increased spontaneous and directed granulocyte migration was observed in 6 out of 7 patients before steroid treatment. In 5 patients these parameters were reduced after treatment. In contrast to this, decreased chemotaxis of polymorphonuclear granulocytes (PMN) from patients with Rheumatoid Arthritis (RA), have been reported earlier. This has been suggested as a partial explanation of the increased morbidity of these patients. Plasma levels of Complement C3d were initially increased in all patients and were slightly reduced following treatment. PMN migration in highly active RA cases is increased and responds markedly to steroid treatment, in contrast to the complement activation. The mainly unaffected, increased levels of plasma C3d might, in part, explain the early recurrence of symptoms often seen when steroid medication is withdrawn. Our results contrast with earlier findings and need to be confirmed in further studies.

Acute Disease↗
PubMed1988

ELISA estimations of rheumatoid factor IgM, IgA, and IgG in sera from RA patients with high disease activity. DTT treatment studies.

Although Elisa assays detecting rheumatoid factor's (RF) show high sensitivity and specificity, difficulties with IgA- and especially IgG-RF testing in ELISA systems, due to interaction from 'contaminating' IgM-RF is still thought to be a problem. Sera from 15 Rheumatoid Arthritis patients with high disease activity and high IgM-RF values were Dithiothreitol (DTT) treated. IgM-RF values were reduced to approximately zero in all tested sera. IgA-RF activity declined as expected, but also showed a statistically significant correlation between % reduction after DTT treatment and the IgM-RF value from the same serum sample. IgG-RF also decreased after DTT treatment, most pronounced for high IgG-RF values. A correlation (not statistically significant) between the % reduction in IgG-RF after DTT treatment and the IgM-RF value from the same serum sample was observed. Pepsin and Diethylammonium ethyl (DEAE) reduced the IgG-RF activity even more than after DTT treatment of the sera. Fractionation by Gel filtration of 8 serum samples showed that all the RF activity were found according to the 'first top' of the gel filtration curve.

Arthritis, Rheumatoid↗