Magnetic resonance evaluation after temporomandibular joint diskectomy.

The aim of this study was to investigate the value of magnetic resonance imaging after diskectomy of the temporomandibular joint. Magnetic resonance images were obtained before and 12 months after unilateral diskectomy without disk replacement. Magnetic resonance findings at follow-up were correlated to residual pain. At the follow-up, 20 of 28 patients were free of pain in the joint that had been surgically treated, four patients had mild pain, and four patients had significant residual pain. The magnetic resonance images at follow-up showed that the joint space was filled with soft tissue after diskectomy. In patients without pain at follow-up, this soft tissue had a magnetic resonance signal that was equal or higher than that of the muscles. In the four patients with significant residual pain and in one patient with mild residual pain, the soft tissue in the joint space between the condyle and glenoid fossa had a magnetic resonance signal intensity that was lower than the muscle. On the basis of findings in a previous study, the areas of low signal intensity were interpreted as fibrous adhesions. The study suggests that areas of low signal intensity in the joint space appear to be associated with residual pain and that magnetic resonance imaging could be a valuable tool for assessment of the temporomandibular joint after diskectomy.     

Manganese induced brain lesions inMacaca fascicularis as revealed by positron emission tomography and magnetic resonance imaging

A series of positron emission tomography scans was made on two monkeys during a 16-month period when they received manganese(IV)oxide by subcutaneous injection. The distribution of [¹¹C]-nomifensine uptake, indicating dopamine terminals, was followed in both monkey brains. The brain distributions of [¹¹C]-raclopride, demonstrating D₂ dopamine receptors, and [¹¹C]-l-dopa, as a marker of dopamine turnover, were followed in one monkey each. The monkeys developed signs of poisoning namely unsteady gait and hypoactivity. The [¹¹C]-nomifensine uptake in the striatum was reduced with time and reached a 60% reduction after 16 months exposure. This supports the suggestion that dopaminergic nerve endings degenerate during manganese intoxication. The [¹¹C]-l-dopa decarboxylation was not significantly altered indicating a sparing of [¹¹C]-l-dopa decarboxylation during manganese poisoning. A transient decrease of [¹¹C]-raclopride binding occurred but at the end of the study D₂-receptor binding had returned to starting values. The magnetic resonance imaging (MRI) revealed that the manganese accumulated in the globus pallidus, putamen and caudate nucleus. There were also suggestions of gliosis/edema in the posterior limb of the internal capsule. MRI might be useful to follow manganese intoxication in humans as long as the scan is made within a few months of exposure to manganese, i. e. before a reversal of the manganese accumulation.     

Hydroxyurea-induced cell death in human T lymphoma cells as related to imbalance in DNA/protein cycle and deoxyribonucleotide pools and DNA strand breaks.

The aim of this study was to elucidate the mechanism(s) behind the cellular toxicity of therapeutic concentrations of hydroxyurea (HU). Treatment of human T lymphoma cells (CCRF-CEM) with 60-100 microM of HU for 24 h decreased the growth rate by 90% due to accumulation of cells in early S phase. It induced a marked imbalance in both the DNA/protein cycle (as measured by two-parameter flow cytometry) and the deoxyribonucleotide (dNTP) pools. HU treatment did not enhance the frequency of DNA single-strand breaks (SSBs), as measured by the alkaline unwinding technique. Cell viability was unaffected. However, removal of HU led to 10-15% cell loss during the following 12 h period in parallel with increasing SSBs, and a rapid progression of cells through S and G2 stages. The unbalanced DNA to protein content per cell and the dNTP pools were normalized 6-12 and 24 h after removal of HU, respectively. These results show that marked changes in the DNA to protein ratio and dNTP pools alone are not directly lethal, but when combined with a high replicative DNA synthesis rate, as found after removal of HU, apparently lead to elevated cell death.     

Effects of glutathione-modulating agents on the covalent binding and toxicity of dichlobenil in the mouse olfactory mucosa.

Twenty-four hours following injection of a single dose of the herbicide dichlobenil (2,6-dichlorobenzonitrile) in C57Bl/6 mice a steep dose-response curve for the histopathological toxicity in the olfactory mucosa was observed. Four hours following injection of a toxic dose of [ring-14C]dichlobenil (12 mg/kg) the covalent binding in the olfactory mucosa was 26 times higher than that in the liver. A dose-dependent decrease of nonprotein sulfhydryls (mainly glutathione, GSH) in the olfactory mucosa was observed 2.5 hr following injection of dichlobenil (6, 12, 25 mg/kg). The synthetic GSH precursor N-acetyl-L-cysteine decreased both the dichlobenil-induced toxicity and the covalent binding, whereas N-acetyl-D-cysteine had no effect. No protective effects of the cyanide antidotes nitrite, thiosulfate, or superoxide dismutase on the dichlobenil-induced toxicity were observed. In mice given the GSH-depleting agent phorone and a subtoxic dose of dichlobenil (6 mg/kg), an extensive toxicity and an increased covalent binding in the olfactory mucosa were demonstrated. Autoradiography showed no change in the distribution of covalent [14C]dichlobenil binding to nontarget tissues of phorone-treated mice. In conclusion, the results demonstrate a relationship between the degrees of covalent binding, GSH depletion, and toxicity of dichlobenil in the olfactory mucosa. Hence, the level of GSH appears to be of importance for the dichlobenil-induced toxicity in the olfactory mucosa.     

Nursing leaders' and nurses' view of health

This study is part of a scientific project, 'Multidimensional Health', the main goal of which is to introduce a broad view on health into health care and nursing The purpose of this study is to examine the view of health among nursing leaders and members of caring staff and to compare it to that of patients (a previous study in the project) The study is based on K Eriksson's theory of caring and its view of the human being with a body, soul and spirit, and health as a dynamic process concerning all aspects of human life An inquiry form with open questions that brought to the fore various aspects and dimensions of health was filled in by 20 nursing leaders and was used in interviewing 49 nurses According to the results many aspects of life are contained in the concept 'health' Health is above all an experience of well-being Ways of promoting one's health are described in terms of various 'healthy' living habits and preventive measures A supporting and humane attitude is hoped for in others There is unanimity that feelings affect health Belief may have a positive influence on health The meaning of life is connected with health Even suffering is part of health In interpreting the answers we assume three dimensions of health 'Health as behaviour' connects health with living in a healthy way 'Health as being' would mean a state of health and is characterized by a search for some kind of balance in one's inner state 'Health as becoming', growing towards health, means that a person becomes whole on a higher level of integration     

Pharmacokinetics of the enantiomers of felodipine in the dog after oral and intravenous administration of a pseudoracemic mixture

1. A pseudoracemic mixture of deuterated (S)-felodipine and unlabelled (R)-felodipine was administered as single i.v. or oral doses to four dogs. Plasma concentrations of the enantiomers and their corresponding pyridine metabolites were determined by g.l.c.-mass spectrometry. 2. No isotope effects were observed after oral administration of equimolar amounts of deuterated and unlabelled (S)-felodipine. 3. The pharmacokinetic parameters of the enantiomers were similar after i.v. administration, indicating that the disposition of felodipine was not stereoselective. 4. After oral administration the bioavailability of (R)-felodipine was slightly higher than that of (S)-felodipine in two of the dogs, presumably due to a lower first-pass extraction of the (R)-enantiomer, while no difference was observed in the other two dogs. 5. No substantial differences in Cmax or AUC were observed between the deuterated and unlabelled pyridine metabolites, indicating that the oxidative clearances of the felodipine enantiomers were similar.     

The intrinsic activities of the partial dopamine receptor agonists (-)-3-PPP and TDHL on pituitary dopamine receptors are lower in female than in male rats

The abilities of the mixed agonists/antagonists on dopamine (DA) receptors, (-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine [-)-3-PPP) and transdihydrolisuride (TDHL), to suppress serum prolactin levels in acutely hyperprolactinemic male and female rats were investigated. gamma-Butyrolactone was used to deplete endogenous DA and raise serum prolactin concentrations. Both (-)-3-PPP and TDHL were found to cause sexually differentiated responses: (-)-3-PPP reduced serum prolactin levels dose dependently and effectively in males but caused only a modest decrease of prolactin release in females. Moreover, (-)-3-PPP antagonized the prolactin-suppressing effects induced by the DA receptor agonist (+)-3-PPP in females. Likewise TDHL decreased prolactin secretion markedly in males while it had only slight effects in females. It can be concluded from these results that the intrinsic activities of the partial DA agonists (-)-3-PPP and TDHL are lower in female than in male rats, suggesting a reduced responsiveness of hypophyseal DA receptors in females. Since DA levels in the pituitary portal circulation are higher in female than in male rats, this study gives further support to the hypothesis claiming an inverse relationship between the intrinsic activity of a mixed agonist/antagonist and the degree of previous stimulation of its receptor.     

Tracers for aerosol ventilation scintigraphy: Tc-99m versus In-113m

113mIn has been proposed as a suitable tracer for aerosol ventilation scintigraphy in combination with 99mTc pulmonary perfusion scintigraphy. The high energy (393 keV) of 113mIn allows it to be detected in the presence of 99mTc, but degrades the spatial resolution which can be achieved. We have compared the resolution obtained with 99mTc and 113mIn in phantom experiments and in aerosol ventilation scans in 14 patients with airways disease. The resolution at the distances from the collimator encountered in lung scintigraphy was 10-20 mm for 99mTc and 15-40 mm for 113mIn. Aerosol ventilation images were abnormal in all patients. The 99mTc images showed peripheral defects and frequently central hot spots reflecting increased local aerosol deposition. In the 113mIn images, the lower resolution had a smoothing effect, the central hot spots were less striking, and the distribution of activity appeared more uniform, some detail was lost in the periphery. It is suggested that 113mIn is useful for ventilation scintigraphy in the diagnosis of pulmonary embolism, but that 99mTc is the tracer of choice if aerosol ventilation scintigraphy is used to study airways disease.     

Comparison of ionic and non-ionic nitroxide spin labels for urographic enhancement in magnetic resonance imaging

Two nitroxide spin labels (NSL) were compared for in vitro relaxivity and in normal rats for efficiency of urographic enhancement. One of the NSL, PCA, a pyrrolidinyl agent, was ionic and one, NAT, was a non-ionic pyrrolidinyl NSL with multiple hydroxyl substituents for water solubility. Using both NSLs the renal medulla and papilla were noted to show greater contrast enhancement than the cortex, with a maximum enhancing effect between 5 and 15 minutes. Using doses of 1.0 and 2.5 mmol/kg, more than 100 per cent increases in spin echo intensities above the baseline were observed. The lowest tested dose of 0.1 mmol/kg showed an easily detectable enhancing effect for NAT. The good contrast enhancing properties of NAT, considered together with its better acute tolerance, justifies further investigation of this non-ionic compound.     

Mothers' Anticipation and Prevention of Unintentional Injury to Young Children in the Home

Investigated anticipation and prevention of children's unintentionalinjuries in the home. 150 mothers of 1-, 2-, and 3-year-oldchildren kept weekly diaries of anticipated injuries and unanticipatedinjuries/near injuries to their child. Mothers anticipated between57 and 67% of all injury events, a majority when the child wasin the same room as the injury-causing agent prior to interactingwith it. Few anticipated injuries led to injury. In these casesno significant differences were found depending on child's ageand sex. In contrast, mothers of younger children most frequentlyreported preventing injury by physically restricting or movingthe child away and by changing the environment, whereas mothersof older children more frequently engaged in teaching.