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Biomedical subjects

J Nielsen

Publications and source records attributed to J Nielsen.

At least 253 records · Page 14Linked to original sources
PubMed1994

Growth hormone and 17 beta-oestradiol treatment of Turner girls--2-year results.

Girls with Turner syndrome are mainly characterized by growth retardation and gonadal insufficiency. In order to evaluate the effect of growth hormone (GH) and/or low dose 17 beta-oestradiol (E2) on growth and pubertal development, 39 Turner girls with a chronological age (CA) of 7.6-18.1 years were divided into three groups depending on pretreatment bone age (BA). They were treated with either GH 0.1 IE/kg per day (n = 13, BA 7.1-10.2), peroral E2 0.01 mg/kg per day (n = 8, BA 8.5-12.7) or both (n = 18, BA 10.5-15.3). In the 2nd year the E2 group also received GH, while the E2 dose was reduced 30%. In the 1st year height velocity (HV) expressed as standard deviation scores (SDS) increased in all groups (mean): from -0.4 to 3.3 (P < 0.01) in the GH group, -0.5 to 2.7 (P < 0.01) in the E2 group, and -0.8 to 4.6 (P < 0.001) in the GH+E2 group. A possible synergistic effect from combination therapy was seen, as HV increase was higher in group 3 than groups 1 and 2 (P < 0.05). In the 2nd year HV was unchanged in groups 1 and 2, while a clear decrease was seen in the GH+E2 group (P < 0.001). In the 1st year BA progression in the E2 group was rapid (1.9 BA/CA year) and higher than in the other groups (P < 0.05). In the 2nd year progression slowed down--particularly in the E2 group (0.7 BA/CA year, P = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Isolation of porcine reproductive and respiratory syndrome (PRRS) virus in a Danish swine herd and experimental infection of pregnant gilts with the virus.

The first case of porcine reproductive and respiratory syndrome (PRRS) in Denmark was diagnosed in March 1992 by the detection of specific antibodies against PRRS virus in serum samples originating from sows in a herd located on the island of Als. Subsequently, PRRS virus was isolated from a 200-sow farrow-to-finish herd with clinical signs consistent with PRRS. The virus was isolated by inoculation of pleural fluid from a stillborn piglet onto porcine pulmonary alveolar macrophages. The isolate was identified as PRRS virus by staining with a specific antiserum. By electron microscopy, the virus particle was found to be spherical and enveloped, measuring 45-55 nm in diameter and containing a 30-35 nm nucleocapsid. Only minor antigenic differences were found between the Danish and a Dutch isolate. Following intranasal inoculation of 3 pregnant gilts with the Danish isolate transplacental infection was demonstrated by the re-isolation of PRRS virus from approximately 45% of the piglets from the experimentally infected gilts. However, the experimental infection produced no significant reproductive disorders or other clinical signs. At autopsy, histopathological examination revealed slight interstitial pneumonia in a few piglets.

Abortion, Veterinary↗
PubMed1994

Disynaptic reciprocal inhibition of ankle extensors in spastic patients.

The soleus Hoffmann-reflex (H-reflex) was conditioned by a preceding stimulation of the common peroneal nerve in 74 healthy control subjects and 39 patients with spasticity in the lower extremities due to multiple sclerosis. At a conditioning-test interval of 1-3 ms a decrease of the size of the soleus H-reflex was seen in the healthy subjects. The decrease was most likely caused by disynaptic reciprocal Ia inhibition (Crone et al., 1987). In the spastic patients a similar short-latency inhibition was rarely seen. On the contrary, in several patients a facilitation was seen at a conditioning-test interval of 3-4 ms. A short-latency inhibition as pronounced as in healthy subjects was seen in four patients. These four patients did not differ from the other patients regarding the degree of spasticity or any other clinical parameter. However, they all used an external peroneal nerve stimulator daily as a walking aid. It is suggested that the lack of short-latency reciprocal inhibition reflects a deficient control of the interneurons which mediate this inhibitory spinal mechanism between antagonistic muscles in man. This might contribute to the pathophysiology of spasticity and it might be related to the frequent occurrence of co-contraction of functionally antagonistic muscles during gait in spastic patients. The existence of a pronounced reciprocal inhibition in patients receiving frequent stimulation of the peroneal nerve may suggest that regular activation of peripheral nerves is of importance for the maintenance of the activity in spinal pathways.

Adult↗
PubMed1994

Big flies, small repeats: the "Thr-Gly" region of the period gene in Diptera.

The region of the clock gene period (per) that encodes a repetitive tract of threonine-glycine (Thr-Gly) pairs has been compared between Dipteran species both within and outside the Drosophilidae. All the non-Drosophilidae sequences in this region are short and present a remarkably stable picture compared to the Drosophilidae, in which the region is much larger and extremely variable, both in size and composition. The accelerated evolution in the repetitive region of the Drosophilidae appears to be mainly due to an expansion of two ancestral repeats, one encoding a Thr-Gly dipeptide and the other a pentapeptide rich in serine, glycine, and asparagine or threonine. In some drosophilids the expansion involves a duplication of the pentapeptide sequence, but in Drosophila pseudoobscura both the dipeptide and the pentapeptide repeats are present in larger numbers. In the nondrosophilids, however, the pentapeptide sequence is represented by one copy and the dipeptide by two copies. These observations fulfill some of the predictions of recent theoretical models that have simulated the evolution of repetitive sequences.

Amino Acid Sequence↗
PubMed1994

Nasal challenge shows pathogenetic relevance of specific IgE serum antibodies for nasal symptoms caused by hexahydrophthalic anhydride.

Hexahydrophthalic anhydride (HHPA) is a component of some epoxy resin systems. A high fraction of HHPA-exposed workers display nasal symptoms, and some of them have specific serum antibodies. To test the pathogenetic relevance of the antibodies nasal challenge tests were performed with a conjugate of HHPA and human serum albumin (HSA) at three increasing concentrations. Eleven subjects, who were IgE-sensitized against HHPA (positive in RAST and in skin-prick test against the HHPA-HSA conjugate), and who reported work-related nasal symptoms, had a significant increase of nasal symptoms and a decrease of nasal inspiratory peak flow after the challenges. The symptoms were associated with specific serum IgE, but with IgG. Further, significant increases were found in eosinophil and neutrophil counts, and in levels of tryptase, and albumin, whereas no clear rise was recorded for eosinophil cationic protein in nasal lavage fluid. Nine subjects, who were not sensitized, but who complained of work-related nasal symptoms, and 11 subjects, who were not sensitized and had no symptoms, displayed no significant change in any of these parameters. It is concluded that the symptoms in some of the workers were caused by an IgE-mediated mast cell degranulation, followed by an inflammatory reaction, engaging eosinophil and neutrophil cells.

Adult↗
PubMed1994

Symptoms and immunologic markers induced by exposure to methyltetrahydrophthalic anhydride.

A study was performed in 43 workers exposed to methyltetrahydrophthalic anhydride (MTHPA) used as a hardener in an epoxy resin system. Ten workers sensitized to MTHPA (group SS; presence of serum IgE antibodies against a conjugate of MTHPA and human serum albumin (HSA) detected by RAST) had significantly higher levels of tryptase in nasal lavage fluid than 19 nonsensitized workers with work-related nasal symptoms (group NS) and 14 nonsensitized workers without nasal symptoms (group NN). This suggests an ongoing mast-cell-mediated reaction in the sensitized group. No statistically significant differences were found in the three groups concerning eosinophil cationic protein (ECP) and TAME-activity in lavage fluid. However, there was a significant increase in serum ECP in the SS group, as compared with a group of unexposed controls. Nasal challenge with MTHPA-HSA, performed in a subsequent study in seven workers from the SS group, six from the NS group, and seven from the NN, caused a larger increase of symptom score and a more pronounced decrease in nasal inspiratory peak flow in the SS group than in the other two groups. No significant rise was recorded for tryptase and ECP in lavage fluid in any of the three groups after challenge. The combined results of the two studies indicate that specific IgE antibodies play a pathogenetic role in at least some of the cases of work-related nasal symptoms associated with MTHPA exposure.

Blood Proteins↗
PubMed1994

Angiotensin II receptor density in bovine ovarian follicles relates to tissue renin and follicular size.

1. The purpose of this study was to investigate angiotensin II (AII) receptors in isolated bovine ovarian follicles and the relationship of their density to follicular concentrations of prorenin, active renin, oestradiol and progesterone. 2. Displacement of [125I]-[Sar1-Ile5-Ile8]-AII binding by the AII receptor antagonists PD 123319 and Losartan (DuP 753) confirmed that follicular AII receptors are of subtype 2 (AT2 receptor). 3. The dissociation constant (Kd) for [Ile5]-AII (human AII) was 0.84 (range 0.51-1.47) nmol/L. The receptor density varied between 90 and 5990 (mean 1640) fmol/mg membrane protein. 4. The follicular AII receptor density correlated positively with follicular diameter (Spearman's rho = 0.518; P < 0.003) and tissue weight (Spearman's rho = 0.636; P < 0.0001), and negatively with the active renin concentration in the follicular wall (Spearman's rho = -0.399; P < 0.02). The AII receptor density did not correlate with the follicular fluid concentrations of prorenin, active renin, oestradiol (E2), progesterone (P4) or the E2/P4 ratio. The follicular fluid concentrations of prorenin correlated negatively with the E2/P4 ratio (Spearman's rho = -0.716; P < 0.0001). 5. The inverse relationship between AII receptor density and the high active renin concentrations in the follicular wall suggests an active regulated tissue renin-angiotensin system. A high AII receptor density is a general feature of large bovine ovarian follicles.

Angiotensin II↗
PubMed1994

Lactate and pyruvate concentrations in capillary blood from newborns.

Using high pressure liquid chromatography on strong cation exchange column, we analyzed capillary blood from 141 healthy full-term newborns for lactate and pyruvate concentrations. Total range of lactate was 367-3245 mumol/l and reference interval (mean +/- 2 SD) was 260-2212 mumol/l. Total range of pyruvate was 10-141 mumol/l and reference interval (10th/90th percentile) was 12-71 mumol/l.

Adolescent↗
PubMed1994

Central control of disynaptic reciprocal inhibition in humans.

The disynaptic pathway from muscle spindle Ia afferents to motoneurones of the antagonist muscle is one of the best studied pathways in the spinal cord. Early animal studies--mainly in the cat--have provided a detailed knowledge of the pathway itself and of the integration of segmental and supraspinal convergence at the interneuronal level. Although this knowledge was used to formulate hypotheses on the function of the pathway during natural movements, the reduced animal preparation limited the possibilities of testing these ideas. However, such information has more recently been obtained from human subjects by using indirect electrophysiological techniques. In most of these experiments the disynaptic Ia inhibition was demonstrated as a short-latency depression of a monosynaptic test reflex (H-reflex) following a conditioning stimulation of the antagonist nerve. Changes in the size of this depression during voluntary tasks were then taken as evidence of a central regulation of the pathway. It has for example been demonstrated in this way that the brain regulates the Ia inhibitory interneurones in parallel with their corresponding motoneurones during extension-flexion movements, but not during co-contraction of antagonistic muscles. The importance of the central control of the pathway has also been emphasized by the finding of a disordered regulation of its activity in patients with lesions of the brain. This may possibly contribute to the inappropriate co-contraction of antagonistic muscles observed in some of these patients. It seems reasonable to expect that this kind of experiment in the future may contribute significantly to the knowledge of the central control of spinal motor mechanisms.

Humans↗
PubMed1994

Galactose Expulsion during Lactose Metabolism in Lactococcus lactis subsp. cremoris FD1 Due to Dephosphorylation of Intracellular Galactose 6-Phosphate.

In Lactococcus lactis subsp. cremoris FD1, galactose and lactose are both transported and phosphorylated by phosphotransferase systems. Lactose 6-phosphate (lactose-6P) is hydrolyzed intracellularly to galactose-6P and glucose. Glucose enters glycolysis as glucose-6P, whereas galactose-6P is metabolized via the tagatose-6P pathway and enters glycolysis at the tagatose diphosphate and fructose diphosphate pool. Galactose would therefore be a gluconeogenic sugar in L. lactis subsp. cremoris FD1, but since fructose 1,6-diphosphatase is not present in this strain, galactose cannot serve as an essential biomass precursor (glucose-6P or fructose-6P) but only as an energy (ATP) source. Analysis of the growth energetics shows that transition from N limitation to limitation by glucose-6P or fructose-6P gives rise to a very high growth-related ATP consumption (152 mmol of ATP per g of biomass) compared with the value in cultures which are not limited by glucose-6P or fructose-6P (15 to 50 mmol of ATP per g of biomass). During lactose metabolism, the galactose flux through the tagatose-6P pathway (r(max) = 1.2 h) is lower than the glucose flux through glycolysis (r(max) = 1.5 h) and intracellular galactose-6P is dephosphorylated; this is followed by expulsion of galactose. Expulsion of a metabolizable sugar has not been reported previously, and the specific rate of galactose expulsion is up to 0.61 g of galactose g of biomass h depending on the lactose flux and the metabolic state of the bacteria. Galactose excreted during batch fermentation on lactose is reabsorbed and metabolized when lactose is depleted from the medium. In vitro incubation of galactose-6P (50 mM) and permeabilized cells (8 g/liter) gives a supernatant containing free galactose (50 mM) but no P(i) (less than 0.5 mM). No organic compound except the liberated galactose is present in sufficient concentration to bind the phosphate. Phosphate is quantitatively recovered in the supernatant as P(i) by hydrolysis with alkaline phosphatase (EC 3.1.3.1), whereas inorganic pyrophosphatase (EC 3.6.1.1) cannot hydrolyze the compound. The results indicate that the unknown phosphate-containing compound might be polyphosphate.

Journal Article↗
PubMed1994

Prevalence of cardiovascular malformations and association with karyotypes in Turner's syndrome.

The aim of the study was to establish the prevalence of cardiovascular malformations in females with Turner's syndrome and analyse possible associations with the various karyotypes. One hundred and seventy nine of 393 females who had Turner's syndrome diagnosed in Denmark were examined. Complete chromosome analysis was available in all cases. Clinical examination, electrocardiography, and echocardiography including Doppler were performed. The distribution of the various karyotypes was 45,X, 58%; mosaic monosomy X, 35%; and structural abnormalities of the X chromosome, 7%. In 46 (26%) of the females a total of 69 cardiovascular malformations were found; aortic valve abnormality (18%) and aortic coarctation (10%) being the most common. There was a significant difference in the prevalence of cardiovascular malformations between 45,X and mosaic monosomy X (38% v 11%), primarily due to a significant difference in the prevalence of aortic valve abnormalities and aortic coarctation. Pulmonary valve abnormalities were seen only in females with mosaic monosomy X but the prevalence was low (3%). No patient with structural abnormalities of the X chromosome had cardiovascular malformations.

Adolescent↗
PubMed1994

Do local hospitals meet the analytical goals for the use of common reference intervals?

Blood samples were obtained from 183 blood donors and measured in two hospitals in the same geographical area using identical reference intervals and measuring equipment. The analytical bias of the clinical chemical analyses was investigated through paired measurements. The results showed that out of 15 routine analyses only four meet the goals for acceptance of common reference intervals, of which at least three were of clinical significance. The problems were reflected in the quality assessment results but, nevertheless, no action seems to have been taken.

Adult↗
PubMed1994

29-week doxazosin treatment in patients with symptomatic benign prostatic hyperplasia. A double-blind placebo-controlled study.

In a placebo-controlled study, the safety and efficacy of the selective alpha 1-adrenoceptor-blocking agent doxazosin 4 mg once daily in the symptomatic treatment of benign prostatic hyperplasia (BPH) were evaluated. One hundred patients were primarily included in a 9-weeks study, and after this 75 patients accepted to continue in the present 20 weeks extension. Of the patients in the doxazosin-group (DG) 61% reported overall improvement against 53% in the placebo-group (PG)--(p = 0.56). In the DG, 49% of obstructive symptoms were improved compared to 27% in the PG (p < 0.01), and a reduction of 60% of irritative symptoms was found in the DG against 36% in the PG (p < 0.01). Daytime frequency was reduced by median 1.5 in the DG and remained unchanged in the PG (p < 0.01). Nocturia was reduced by median 1 and 0.5 respectively (p = 0.06). Maximum urinary flow rate (MFR) was improved by median 1.5 ml/s in the DG, while it deteriorated by median 0.5 ml/s in the PG (p < 0.05), Considering postvoid residual urine volume, cystometry variables (first sensation and bladder capacity), changes in sexual function and adverse events there was no difference between the two groups. In conclusion, doxazosin 4 mg once daily in long-term treatment of patients with BPH reduces both obstructive and irritative symptoms, daytime voiding frequency and although only slightly, significantly augments MFR without interference with sexual function and without other serious adverse effects.

Aged↗