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Biomedical subjects

E Christiansen

Publications and source records attributed to E Christiansen.

At least 73 records · Page 4Linked to original sources

[Smoking and diabetes mellitus].

The prevalence of smokers among patients with diabetes is found to be lower than in the population as a whole. Diabetic patients have increased morbidity and mortality from cardiovascular diseases and, in the majority of investigations, smoking is found to be a risk factor in this relationship which does not differ quantitatively from that found in non-diabetics. On the basis of the literature, it has not proved possible to quantitate smoking as a risk factor for the development of peripheral arteriosclerotic vascular disease. Smoking involves hormonal and metabolic changes which are of particular interest in relation to diabetes mellitus. Thus, smoking stimulates the secretion of the antiinsulin hormones, particularly catecholamines, resulting in subcutaneous vasoconstriction which may be unfortunate as it influences insulin absorption. Patients who smoke do not, however, appear to present poorer glycaemic control than non-smokers. A few investigations have shown that smokers have greater insulin requirements than non-smokers. In type 1 (insulin-dependent) diabetes, there is evidence to suggest that diabetic nephropathy and proliferative retinopathy occur more frequently in smokers than in non-smokers. Smoking aggravates the pre-existing more pronounced osteoporosis which occurs in female insulin-dependent patients. It is therefore advantageous to advise diabetic patients against smoking from the point of view of diabetes as such.

Cardiovascular Diseases↗

Acute bleeding from leiomyoblastoma of the greater omentum. A case report.

Extragastric leiomyoblastomas are extremely rare. This is the sixth reported case of leiomyoblastoma of the greater omentum, and the only one with acute major bleeding which required an emergency operation. Leiomyoblastomas are low-grade malignant tumors, and especially the gastric ones have an excellent prognosis after surgical removal. Extragastric leiomyoblastomas have a higher rate of dissemination. However, none of the previously reported omental leiomyoblastomas showed signs of metastatic spread at the time of operation. The present patient is alive and well 18 months post-operatively.

Adult↗

Physiological profiles of episodic progesterone release during the midluteal phase of the human menstrual cycle: analysis of circadian and ultradian rhythms, discrete pulse properties, and correlations with simultaneous luteinizing hormone release.

To define the physiological relationships between episodic progesterone and LH release, we measured serum progesterone and LH concentrations in blood sampled at 10-min intervals for 24 h in seven young women in the midluteal phase of the menstrual cycle. The resultant time series were assessed further by Fourier transformation, Cluster analysis, and cross-correlation analysis with autoregressive modeling. These techniques permitted an examination of circadian rhythms, discrete (ultradian) pulse properties, and simultaneous or lagged correlations between progesterone and LH release. We found the following. 1) Both serum LH and progesterone concentrations had significant circadian periodicities, with similar acrophases (times of maximal nyctohemeral values). LH and progesterone also manifested multiple ultradian rhythms of similar periodicities (range, 48-241 min). 2) Discrete serum progesterone peaks occurred at a mean interpulse interval of 118 +/- 12 (+/- SE) min, had durations of 92 +/- 12 min, and had incremental amplitudes of 4.3 +/- 0.9 ng/mL (14 +/- 3 nmol/L). The frequency and duration characteristics of the progesterone and LH peaks were not significantly different, but progesterone fractional peak amplitudes were one quarter those of LH pulses. 3) Fractional progesterone peak amplitudes in the seven women correlated inversely (r = -0.811) with 24-h mean LH concentrations, suggesting a negative feedback relationship between progesterone and LH release. 4) LH and progesterone interpulse intervals both exhibited significant nyctohemeral variations, with diurnal amplitudes of 73 +/- 12 min for LH and 43 +/- 8.9 min for progesterone (P less than 0.01). 5) Significant positive cross-correlations existed in all seven women between serum LH and progesterone concentrations considered simultaneously and at progesterone time lags of 10-50 min. By autoregressive modeling, the later (20-50 min) cross-correlations could be accounted for by sustained autocorrelations in the individual progesterone and LH time series and significant cross-correlations between LH and simultaneous progesterone concentrations and between LH and 10-min lagged progesterone concentrations. We conclude that progesterone release occurs in a periodic (circadian and ultradian) fashion as well as in a discrete (episodic or pulsatile) mode. Moreover, both positive and negative feedback relationships operate to coordinate LH and progesterone secretion in the midluteal phase of the human menstrual cycle.

Adult↗

Modulating actions of estradiol on gonadotropin-releasing hormone-stimulated prolactin secretion in postmenopausal individuals.

The temporal aspects of estrogen treatment on serum prolactin concentrations basally and in response to a 10 micrograms intravenous injection of gonadotropin-releasing hormone were assessed in eight postmenopausal women. The response of prolactin to gonadotropin-releasing hormone stimulation was compared with that of follicle-stimulating hormone and luteinizing hormone obtained simultaneously. Basal serum prolactin increased significantly (p less than 0.001) in response to estrogen treatment, and a positive correlation was found between the serum concentrations of estradiol and prolactin (r2 = 0.266; p = 0.0011). Gonadotropin-releasing hormone induced a significant increase in serum prolactin concentrations, which was greater after 5 to 10 days of estrogen treatment compared with that in the estrogen-depleted state (p = 0.031). No correlation was found between gonadotropin-releasing hormone-stimulated prolactin and luteinizing hormone or follicle-stimulating hormone release. These data demonstrate that estrogen treatment of previously hypoestrogenemic postmenopausal women potentiates gonadotropin-releasing hormone-stimulated prolactin release. Furthermore, our data suggest that the previously described paracrine interaction between the gonadotropins and lactotropes exerted by gonadotropin-releasing hormone does not appear to be mediated via increased gonadotropin release.

Estradiol↗

Impact of intensive venous sampling on characterization of pulsatile GH release.

The effect of sampling intensity on quantitative properties of pulsatile growth hormone (GH) release was tested using an objective, statistically based pulse detection algorithm (Cluster). Seven normal young men had blood withdrawn at 5-min intervals for 24 h. The number of GH peaks/24 h (mean +/- SE) detected in the 5-min series (5.93 +/- 0.66) was significantly greater than the number of peaks documented in the constituent 10-min (3.45 +/- 0.28), 15-min (2.79 +/- 0.31), 20-min (2.86 +/- 0.64), 30-min (2.5 +/- 0.36), 45-min (2.21 +/- 0.21), and 60-min (1.93 +/- 0.23) series. The increased number of peaks detected with 5-min sampling reflected high-frequency pulsatile GH release occurring within the major GH secretory episodes. Both the mean widths and areas associated with peaks identified in the 5-min series were smaller than those documented with less intensive sampling. Peak amplitude did not change with sampling intensity. These data suggest that the major secretory episodes of GH release in normal young men encompass high-frequency GH secretory activity. That these high-frequency GH secretory events have not previously been described probably reflects the relatively infrequent sampling paradigms (e.g., every 20-30 min) commonly used in the past.

Adult↗

Effects of essential fatty acid deficiency on mitochondria and peroxisomes in rat hepatocytes with special reference to a partially hydrogenated fish oil diet.

Feeding male rats a high cal% partially hydrogenated fish oil diet induced morphological and biochemical changes in hepatocytes at the mitochondrial and peroxisomal level. At the mitochondrial level, formation of megamitochondria was related to the development of an essential fatty acid deficiency, as measured by a high 20:3/20:4 fatty acid ratio. These mitochondrial changes were fully prevented by adding linoleic acid to the partially hydrogenated fish oil diet. The megamitochondria revealed a normal specific content of respiratory chain pigments, normal specific respiratory rates and a normal energy coupling. At the peroxisomal level, feeding of the partially hydrogenated fish oil diet caused a considerable proliferation, which was unrelated to essential fatty acid deficiency. The total number of peroxisomes increased 1.9-fold, and 2.6-fold in the presence of added linoleic acid. Essential fatty acid deficiency seemed to result in an inhibition of peroxisomal biogenesis. It was concluded that the induction of megamitochondria by partially hydrogenated fish oil was fully attributable to essential fatty acid deficiency, whereas peroxisomal proliferation must be attributed to other factors in the diet.

Animals↗

Myofascial pain and the role of myoglobin.

The plasma myoglobin concentration was measured before and after massage of 26 patients with myofascial pain. Twenty-one patients had a successful treatment and a significant increase was observed in the plasma myoglobin concentration (median 125 micrograms/l, range 35-439) within a maximum of 2 hours after the first massage treatment (p less than 0.0001). A positive correlation was found between the degree of muscle tension and pain, and the increase in plasma myoglobin concentration. After repeated massage treatment a gradual decline in the increase in plasma myoglobin concentration could be demonstrated parallel to a reduction in the muscle tension and pain. Five patients did not benefit from massage treatment and no significant increase in the myoglobin in plasma was measured. These patients were in pain and had a high degree of muscle tension. The observed increase in myoglobin in plasma after massage indicates a leak of myoglobin from the muscle fibres in 21 patients, whose myofascial pain seem to be linked with a muscle fibre disease. It is suggested that 5 patients with the same muscle symptoms have another, still unknown muscle disease.

Adult↗

Dislocation of the temporomandibular joint meniscus: contrast arthrography vs. computed tomography.

A prospective study to determine the accuracy of computed tomography (CT) for the diagnosis of dislocation of the temporomandibular joint (TMJ) meniscus was made by performing both CT and contrast arthrography on 18 joints suspected of meniscus dislocation. Arthrography rather than surgery was chosen as the quality standard for comparing CT findings, as not all patients undergoing the studies underwent surgery. The CT protocol included scanning with both closed- and open-mouth series, 1.5-mm-thick slices, soft-tissue and bone-detail settings, and coronal and sagittal reformations. Arthrography was done with linear tomography, after both lower and upper compartmental injections under fluoroscopic control. The results of each test were reported independently by the radiologist who obtained either all of the arthrograms or all of the CT scans. For dislocation of the meniscus, there was excellent agreement between the two methods. Nine menisci were dislocated according to both arthrography and CT. One meniscus was thought to be dislocated by CT, but this was not confirmed with arthrography. CT seems to be nearly as accurate as arthrography for showing meniscus dislocation, is performed with lower x-ray exposure, and is noninvasive. Arthrography discloses more detailed information about the joint meniscus, such as perforation and maceration, and should continue to be used when this kind of information is clinically important.

Adult↗

Activation of mammalian skeletal-muscle carbonic anhydrase III by arginine modification.

Purified carbonic anhydrase isozymes I, II, and III (CA I, CA II, CA III) from various sources were treated with 2,3-butanedione and their bicarbonate dehydration reactions followed. The specific activities of human and bovine CA I and CA II and chicken CA III were not affected by the butanedione treatment, whereas the activities of human, gorilla, and bovine CA III were rapidly activated. These findings suggest that one, or both, of the two arginyl residues which appear to be unique to the active sites of the mammalian CA III isozymes are modified by butanedione.

Amino Acid Sequence↗

Long-chain Acyl-CoA levels in liver from rats fed high-fat diets: is it of significance for an increased peroxisomal beta-oxidation?

The levels of long-chain acyl-CoA in the livers of rats given diets containing various amounts of dietary oils were investigated. Increasing the amount of soybean oil in the diet from 5% to 25% (w/w) led to a 40% increase in long-chain acyl-CoA. With partially hydrogenated marine oil, a sigmoidal dose-response curve was obtained, giving a 60% increase when 20% or more of this oil was in the diet. All high-fat diets tested resulted in higher levels of long-chain acyl-CoA than the low-fat control containing soybean oil. The increase was most prominent with partially hydrogenated marine and rapeseed oils. With diets containing partially hydrogenated marine oil, the ratio of long-chain acyl-CoA to acid-soluble CoA was increased after 3 days, but decreased after 3 weeks, to a value similar to that observed in animals fed soybean oil because of an extensive increase in acid-soluble CoA. Increased levels of long-chain acyl-CoA were also observed after clofibrate was administered, but the increase was less prominent than observed with high-fat diets. When comparing the levels of long-chain acyl-CoA observed after 3 days on different diets with the peroxisomal beta-oxidation activity previously determined after 3 weeks on the corresponding diets, a straight line was obtained. These results are discussed in relation to the possibility that long-chain acyl-CoA induces peroxisomal beta-oxidation activity.

Acyl Coenzyme A↗

Temporomandibular joints: high-resolution computed tomographic evaluation.

High-resolution computed tomography of the temporomandibular joint (TMJ) was performed in 43 patients. Exquisite detail of the face, skull base, and TMJs was obtained with CT using soft tissue and bone algorithms, narrow collimation, and multiplanar images. In 10 patients clinically suspected of joint derangement, CT results were in close agreement with surgical findings and arthrography in 13/15 joints. CT showed indirect signs of disc dislocation, and the dislocated disc itself in 81% of affected joints. In two patients, arthrography with CT proved to be more helpful than conventional arthrography alone. CT without intra-articular contrast material provided information not appreciated on conventional radiographs in 28 patients (65%) and was particularly helpful in evaluating patients with disc pathosis and trauma. Early experience with CT of the TMJ shows that it is an excellent method of evaluation at acceptable radiation exposure levels that adds essential information not seen on standard radiographs.

Adult↗

The effect of alprenolol on serum myoglobin levels in acute myocardial infarction.

In a group of 37 patients with definite acute myocardial infarction (AMI) allocated to treatment with either alprenolol (n = 20) or placebo (n = 17) serial determinations of concentrations in serum of myoglobin (S-Mb), creatine kinase (S-CK), aspartate aminotransferase (S-ASAT) and lactate dehydrogenase (S-LDH) were performed. The median peak levels of S-Mb, S-CK and S-LDH were significantly (P less than 0.05) lower among patients treated with alprenolol. The median of the estimated infarct size based on S-CK curves was also significantly (P less than 0.01) lower in the alprenolol group. There was no significant difference between the estimated infarct size based on S-Mb values in the two groups. It is concluded that the present study provides indirect evidence for the assumption that early beta-blockade in AMI can reduce infarct size.

Adult↗

Regional muscle tension and pain ("fibrositis"). Effect of massage on myoglobin in plasma.

In thirteen patients, all women, with regional muscle tension and pain ("fibrositis") plasma myoglobin concentration was measured before and after massage. A significant increase was observed in the plasma myoglobin concentration reaching a maximum three hours after the start of massage treatment (median 133 micrograms/l). A positive correlation was found between the degree of muscle tension and the increase in plasma myoglobin concentration. After repeated massage treatment a gradual decline could be demonstrated in the increase of the plasma myoglobin concentration in coincidence with the efficacy of the treatment. Opposed to this only normal levels of myoglobin were found in plasma when muscles without tenderness and pain were treated with massage. The observed increase of myoglobin in plasma after massage indicates a leak of myoglobin from the muscle fibres, which suggests that regional muscle tension and pain is associated with disorders in the muscle fibres.

Adult↗