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Biomedical subjects

A Møller

Publications and source records attributed to A Møller.

85 records · Page 5Linked to original sources

Conization of the cervix uteri. Complications in connection with plain catgut or silk suturing.

During a retrospective study on postoperative complications in 213 patients who had undergone conization, a (non-significant) reduction in the bleeding rate from 27.9% to 18.6% was found when using silk sutures (102 patients) instead of plain catgut (111 patients) for adaption of the edges of the wound (0.1 less than p less than 0.2). The reduction was most pronounced and significant in cases where bleeding had occurred during the first 4 days after surgery, the usual period for hospital stay under normal conditions. After discharge the bleeding rates were more comparable, 12.6% in the catgut group and 16.6% in the silk group. On the other hand, more cases of stenosis of the cervical canal were observed, i.e., 25.5% in the silk group and 8.1% in the catgut group (p less than 0.001). The period of hospitalization was reduced on an average by 2 days when using silk (p less than 0.001).

Adult↗

Some dualistic properties of the cochlear microphonic.

Within a small frequency range just above the characteristic frequency of a differential electrode pair, cochlear microphonic input-output functions are bimodal, exhibiting two maxima. The more sensitive, low-intensity response has a more limited linear operating range, and it is more labile due to acoustic fatigue or hypoxia. After fatigue or hypoxia, the high-intensity response is revealed. The latter operates 180 degrees out-of-phase with the former, presumably due to its being generated more basalward in the cochlea. The difference in the lability of the two components suggests that the two sources are different types of hair cells: i.e., outer and inner hair cells.

Acoustic Stimulation↗

Effect of modulation of basilar membrane position on the cochlear microphonic.

Certain characteristics of the extracellular cochlear microphonic (CM) recorded by intracochlear electrodes change in a bimodal manner as a function of prior acoustic exposure, intensity of stimulation, or stimulus frequency. In the present study, it is shown that biasing the basilar membrane position toward scala tympani serves to enhance the CM amplitude when the cochlea is unfatigued, when low-intensity stimuli are used, or when frequencies below the best frequency of a differential electrode pair are used. Conversely, after acoustic fatigue, or during high-intensity or high-frequency stimulation, the microphonic potential is enhanced by a movement of the basilar membrane toward the scala vestibuli. The two populations of hair cells, whose responses are enhanced and diminished on opposing positions of the basilar membrane, are probably outer and inner hair cells.

Acoustic Stimulation↗

Lipoproteins and diuretics in type II diabetes.

This double-blind cross-over study was performed to investigate whether the lipoproteins in plasma were different on furosemide (Lasix Retard) and thiazide (hydrochlorthiazide) treatment in patients suffering from type II diabetes. Twenty-four patients were randomly allocated to either furosemide-hydrochlorthiazide (LR-HCT) or HCT-LR treatment. The treatment period was 12 months: 6 months on each sequence. After inclusion, the patients were seen every second month. Laboratory data were recorded at each visit. The only significant treatment effect was observed for high-density-lipoprotein3 cholesterol concentration (HDL3 cholesterol concentration), which was higher when patients were on furosemide therapy (p less than 0.05). We conclude from the present study that blood-glucose HbA1c, and the concentration of lipoproteins connected to development of atherosclerosis is unaffected whether type II diabetes patients are treated with HCT or furosemide.

Aged↗

Total number and mean cell volume of neocortical neurons in rats exposed to 2,5-hexanedione with and without acetone.

The toxicological effects of 2,5-hexanedione (2,5-HD) alone and combined with acetone on the number and size of neurons in the cerebral cortex of rats were evaluated with stereological techniques. Thirty rats were equally divided into three groups: One control, one receiving 0.5% 2,5-HD, and one receiving 0.5% 2,5-HD and 0.5% acetone in the drinking water for seven weeks. Unbiased estimates of the total number of neocortical neurons, as well as the mean neuronal nuclei and cell body volumes were obtained from systematically sampled 3.5-microns sections. The total number of neurons in the 2,5-HD group was significantly smaller than the control group (p less than 0.05, one-tailed t-test). Both test groups showed significant changes in the mean cell body volume: Compared with the control group, animals exposed to 2,5-HD had 11% smaller cell body volumes while animals exposed to 2,5-HD and acetone had 13% larger cell body volumes. These data represent the first unbiased estimation of mean cell volume in toxicology. We propose the nucleator method as an efficient and accurate tool for estimating quantitative changes in toxicological research.

Acetone↗

Effects of 2,5-hexanedione alone and in combination with acetone on radial arm maze behavior, the "brain-swelling" reaction and synaptosomal functions.

A multidisciplinary study to investigate 2,5-hexanedione (2,5-HD)-induced CNS-neurotoxicity and its proposed potentiation by acetone (AC) was conducted. Neurobehavioral testing, estimation of the brain-swelling reaction, neuropathological and morphometric measurements as well as synaptosomal 5-hydroxytryptamine (5-HT) uptake were evaluated. Male Wistar rats were exposed through their drinking water, for seven weeks, either to 0.5% 2,5-HD alone or to 0.5% 2,5-HD in combination with 0.5% AC. This 2,5-HD dose is known to cause neurotoxicity in the peripheral nervous system. Exposed animals were compared to a control group that received tap water. Acquisition but not performance of spatial learning, as measured in the radial 8-arm maze, was significantly inhibited by the coexposure to 2,5-HD and AC. Brain weights of rats exposed to 2,5-HD alone and to 2,5-HD and AC in combination, were slightly, albeit significantly, reduced. Synaptosomal high-affinity 5-HT uptake rate and uptake capacity were significantly reduced by 2,5-HD alone and in combination with AC. The morphometric results are reported in a companion paper. In conclusion, the present findings indicate that 2,5-HD is a CNS-neurotoxicant. The hypothesis about AC potentiation of 2,5-HD CNS-neurotoxicity was supported.

Acetone↗

MPTP-induced Parkinsonism in minipigs: A behavioral, biochemical, and histological study.

Fourteen male Göttingen minipigs were used in this study. Nine were administered N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at a dosage of 1 mg/kg/day, SC, for 6 days, the last five pigs received saline injections for 6 days. All MPTP-treated animals developed Parkinson symptoms, i.e., muscle rigidity, hypokinesia, and impaired coordination within 5 days. The brain levels of dopamine (DA), and its major metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were determined in caudatum and putamen 2, 14, and 93 days (n = 3/time point) after the last drug administration. In eight of the MPTP-treated animals, striatal DA, DOPAC, and HVA concentrations were reduced from 50 to 95% compared to control animals at all time intervals. Animals with the lowest striatal DA concentrations showed the most severe signs of Parkinsonism. The number of cells in substantia nigra (SN) showed a decline only 3 months after MPTP treatment. The minipigs represent a nonprimate model of MPTP-induced parkinsonism syndromes lasting at least months.

3,4-Dihydroxyphenylacetic Acid↗

A case of cerebral paragonimiasis in Denmark. Case report.

A case of cerebral paragonimiasis with severe neurological symptoms is presented. The patient, a 45-year-old woman, recovered completely after resection of a large cyst at the C3 level. The pathogenesis is discussed.

Animals↗

The DaNeX study of embryonic mesencephalic, dopaminergic tissue grafted to a minipig model of Parkinson's disease: preliminary findings of effect of MPTP poisoning on striatal dopaminergic markers.

A multicenter study is under way to investigate the efficacy of allografting of embryonic mesencephalic neurons in a pig model of Parkinson's disease. We have first established that a stable parkinsonian syndrome can be established by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication of adult male Göttingen minipigs. We are now using positron emission tomography (PET) methods for testing the physiological responses to MPTP intoxication and the time course of the response to several treatment strategies. We now report preliminary results obtained in 11 pigs employed in the initial phase of the study; the completed study shall ultimately include 30 pigs. Animals were randomly assigned to one of five groups: 1) Control, 2) MPTP intoxication, 3) MPTP intoxication followed by allograft, 4) MPTP intoxication followed by allograft with immunosuppression, and 5) MPTP intoxication followed by allograft with immunosuppression and co-grafting of immortalized HiB5 cells, which had been manipulated to secrete glia cell line-derived neurotrophic factor (GDNF) (approximately 2 ng GDNF/h/10(5) cells). MPTP was administered (1 mg/kg/day, SC) for 7-10 days until the pigs had developed mild parkinsonian symptoms of muscle rigidity, hypokinesia, and impaired coordination, especially of the hind limbs. Approximately 2 weeks after the last MPTP dose, animals received a T1-weighted magnetic resonance imaging (MRI) scan, and a series of dynamic PET recordings. After the first series of PET scans, four grafts of porcine embryonic mesencephalic tissue (E28 days) were placed in each striatum of some MPTP-intoxicated pigs, using MRI-based stereotactic techniques. Immunosuppression of some animals with cyclosporin and prednisolone began just prior to surgery. Two more series of PET scans were performed at 4-month intervals after surgery. After the last scans, pigs were killed and the brains were perfused for unbiased stereological examination of cytological and histochemical markers in striatum and substantial nigra. The behavioral impairment of the animals (the "Parkinson's score") had been evaluated throughout the 8-month period. Kinetic analysis of the first set of PET scans has indicated that the rate constant for the decarboxylation of FDOPA in catecholamine fibers was reduced by 33% in striatum of the mildly parkinsonian pigs. The rate of association of [11C]NS-2214 to catecholamine uptake sites was reduced by 62% in the same groups of pigs. No significant difference was found in the binding potential of [11C]raclopride to the dopamine D2-like receptors in striatum of the MPTP-intoxicated versus control pigs. These preliminary results are suggestive that the activity of DOPA decarboxylase may be upregulated in the partially denervated pig striatum.

Animals↗

Studies on gas tension in the normal middle ear. Gas chromatographic analysis and a new sampling technique.

In studying mechanisms regulating the middle ear pressure it is essential to know the gas compositions of the middle ear. We have constructed a device which made it possible to sample middle ear gas without creating a negative pressure, thus eliminating the risk of admixture of atmospheric air. The samples were analysed by gas chromatography. In 26 normal subjects we found relatively stable values of carbon dioxide (median 52 mmHg, range 31-69 mmHg) and nitrogen (median 605 mmHg, range 563-627 mmHg). The values of oxygen were more fluctuating (median 54 mmHg, range 23-111 mmHg). In 10 of the subjects, arterial gases were determined simultaneously. No correlation could be shown between middle ear and arterial oxygen and carbon dioxide tensions. This investigation provides evidence contradicting the classical theory of a high negative middle ear pressure in Eustachian tube closure. We found strong indications that the Eustachian tube plays an active role in regulating the pressure in the normal middle ear, but variations in blood flow through the middle ear capillaries may also be an important regulating factor.

Adult↗

Gas chromatographic analysis and storage of gas samples from the middle ear.

Methods for storage and analysis of gas samples were studied prior to measuring the composition of gas in the human middle ear cavity. Storage and analysis of gas samples are beset with several pitfalls. The dead space of the sampling syringe must be considered and the gas sample can equilibrate with the surrounding atmosphere, especially if the analysis cannot be done immediately. In this study the equilibration rate was found to fit an exponential function with a time constant of 0.004 min-1. The time constant was reduced by more than a factor of ten when butyl rubber stoppers were used to seal the syringes. Silicone rubber stoppers were less efficient. Disposable plastic syringes were found just as efficient as 'gas-tight' syringes.

Chromatography, Gas↗