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Biomedical subjects

T Larsen

Publications and source records attributed to T Larsen.

At least 19 recordsLinked to original sources

Preoperative investigations for suspected pelvic masses.

Ultrasound examination was performed on 307 patients admitted to Herlev Hospital, Copenhagen, for suspicion of a pelvic tumor. Of these, 194 were operated on, 38 (19.6%) having a malignant tumor and 156 with benign conditions. A solid tumor was suspected in 72 patients on whom intravenous pyelography, barium enema, cystoscopy and rectoscopy were performed, although 11 did not undergo an intravenous pyelography and 12 did not undergo a barium enema. Intravenous pyelography, barium enema, rectoscopy and cystoscopy very seldom gave unsuspected information and never changed the indications for operation. Ultrasound examination of the kidneys, urinary tract, bowel system, liver and retroperitoneum as a complementary investigation to the gynecologic examination of the pelvic tumor gave the same information as did the barium enema, intravenous pyelography, rectoscopy and cystoscopy. Therefore, we conclude that these investigations should be carried out only in patients with symptoms from the urinary tract or the bowel system. Instead, we suggest that ultrasound examination of a pelvic mass also include an examination of the kidneys, urinary tract, bowel system, liver and retroperitoneum.

Adolescent

[Intrauterine hematoma in threatened abortion].

In order to demonstrate the consequences of intrauterine haematoma demonstrated by ultrasound in hospitalised patients with imminent abortion, the course of pregnancy and delivery in patients with demonstrated intrauterine haematoma and patients in whom intrauterine haematoma could not be demonstrated were compared retrospectively. Intrauterine haematoma was demonstrated in 29% of patients with immiment abortion in The Department of Gynaecology and Obstetrics in Herlev Hospital. Patients with intrauterine haematoma were hospitalised more frequently and for more prolonged periods for imminent abortion and for imminent premature delivery. On the other hand, no differences were found in the frequencies of abortion, the birth weights, gestational age on delivery, number of preterm deliveries, frequencies of Caesarean section and adherent placenta between the two groups. Therapeutic bias may have been the cause of the increased number of days of hospitalisation in patients with intrauterine haematoma demonstrated by ultrasound.

Abortion, Threatened

[Pelvic inflammation after induced abortion].

A total of 949 women referred for legal termination of pregnancy in the first trimester participated in an investigation to assess the risk of pelvic inflammation in connection with the intervention in women with and without previous pelvic inflammation in connection with previous pregnancies, the gestational age and the clinical experience of the surgeon. Women who had not borne children developed pelvic inflammation more frequently after legal termination of pregnancy (p < 0.01) than women who had previously borne children. Women with previous pelvic inflammation developed renewed pelvic inflammation, if they had not previously borne children (p < 0.01) or if they had previously undergone legal termination of pregnancy (p < 0.05). Women without previous pelvic inflammation developed pelvic inflammation significantly more frequently, if they had not previously been pregnant (p < 0.05). The occurrence of pelvic inflammation was independent of the gestational age and the clinical experience of the surgeon.

Abortion, Induced

Fibronectin and laminin in transverse tubules of cardiac myocytes studied by laser confocal microscopy and immunocytochemistry.

The distribution of two non-collagenous glycoproteins of high molecular weight, fibronectin (FN) and laminin (LMN), was investigated in myocardial cells from the ventricle of rats, and from biopsies collected from the auricle of patients undergoing a coronary bypass operation. In order to elucidate the expression of FN and LMN across cells, non-invasive serial sectioning has been carried out by laser scanning confocal microscopy of frozen, immunostained tissue sections. In addition, immunoelectron microscopy was used to study the distribution of these antigens at higher magnifications. These studies show that FN is part of the basement membrane of the surface sarcolemma of both ventricular and atrial cells, in addition to being an abundant protein of the extracellular matrix (ECM). Along transverse tubular(TT)-membranes, FN was only detected in tubules exceeding 200 nm in diameter. Even here, the intensity of labelling varied greatly and was generally low. By contrast, a heavy investment of LMN was organized in the basal lamina along the surface sarcolemma and along ramifications of the entire TT-system in ventricular heart muscle cells. In this way, the network of TT-membrane systems of working heart muscle cells provides a supply of LMN to all depths of the myocardial fibre. In human atrial muscle cells, a regular TT-system appears to be absent. Instead occasional, deep sarcolemmal invaginations occur with diameters of 300-500 nm, the surfaces of which are also invested with LMN. The significance of the present findings has been discussed, with special reference to LMN as a possible component of a series of proteins involved in transmembrane communication between the ECM and the sarcoplasm.

Animals

Effect of calcium, copper, and zinc levels in a rapeseed meal diet on mineral and trace element utilization in the rat.

Mineral and trace element interactions were studied in a balance trial with rats. Calcium, copper, and zinc were supplied to a rapeseed meal diet in a factorial design. Animals were fed ad libitum, and absorption, excretion, and retention of the elements were evaluated either as fractions of total intake or in relation to nitrogen retention to account for differences in food intake and lean body mass increment. The intrinsic content of minerals and trace elements was sufficient to support growth at a rate that could be expected from the rapeseed protein quality. However, when calcium was included in the diet, the intrinsic dietary level of zinc appeared to be limiting, despite the fact that the zinc level was twice the recommended level. Additional zinc supply reversed growth impairment. This calcium-zinc interaction is believed to be owing to the formation of phytate complexes. Calcium addition influenced the calcium, phosphorus, magnesium, zinc, and iron--but not the copper--balances. The addition of calcium reduced the availability of the intrinsic zinc, whereas no effect was seen in the zinc-fortified groups. The availability of intrinsic copper was in a similar way significantly impaired by addition of dietary zinc, whereas copper-supplied groups were unaffected by zinc addition. Intrinsic iron availability was also dependent upon zinc addition, although in a more ambiguous way. Thus, addition of extrinsic minerals to a diet high in phytate can result in significant impairments of growth and mineral utilization.

Animals

Tissues and organs as indicators of intestinal absorption of minerals and trace elements, evaluated in rats.

Tissue and organ deposition and blood parameters were evaluated as indices of mineral and trace element absorption in rats. The absorption of elements was quantified in relation to nitrogen retention, i.e., considering the weight gain and new tissue synthesis. A rapeseed meal diet was supplied with three levels of calcium, two levels of zinc, and two levels of copper in a factorial design. In general, an increase in dietary mineral content increased the relative absorption, which in turn, increased the tissue deposition progressively. Striated muscle, however, did not respond to either an increased calcium or zinc supply. Furthermore, an increased calcium absorption caused a depression of the fractional phosphorus and magnesium content of femur bones. The copper content of the kidneys and the heart muscle was directly proportional to the amount of absorbed zinc and iron, respectively. The iron content of tissue was, in general, inversely proportional to zinc absorption and showed a tendency to be directly proportional to copper absorption. The zinc level in tissues was, in a similar way, inversely correlated to measured calcium absorption. In conclusion, interactions between elements do not only affect the intestinal element absorption, but also the distribution of already absorbed elements in tissues and organs.

Animals

Behavioral efficacy of diazepam against nerve agent exposure in rhesus monkeys.

The possibility that nerve agents will be used on the battlefield is real. The traditional therapy against nerve agent exposure consists of pyridostigmine pretreatment and atropine-pralidoxime chloride therapy administered after nerve agent exposure. This therapy regimen is extremely effective in preventing mortality in laboratory animals exposed to multilethal concentrations of nerve agent, yet these animals often display convulsions, brain damage, and behavioral incapacitation. We report here that the addition of diazepam to the traditional therapy for nerve agent (soman) exposure not only decreases the incidence of convulsions, but also attenuates the cognitive impairments of rhesus monkeys trained on a Serial Probe Recognition (SPR) task. Monkeys which received diazepam treatment required only 6 days before their performance on the SPR task returned to presoman exposure levels, compared to nondiazepam-treated monkeys which required 15 days. Moreover, only 1 out of the 5 monkeys which received diazepam treatment suffered tonic-clonic convulsions; in contrast all 5 monkeys which did not receive diazepam treatment experienced severe convulsive episodes. These results suggest that diazepam would be an excellent adjunct to traditional nerve agent therapy to facilitate behavioral recovery from nerve agent intoxication that might be encountered by US military personnel on the battlefield or accidental organophosphate poisoning encountered in industrial or agricultural accidents.

Acetylcholinesterase

Judging fetal growth from body proportions at birth.

Fetal growth velocity from 27 weeks until birth was calculated in 378 infants born after high risk pregnancies from at least three ultrasound measurements of estimated fetal weight and the weight at birth. Anthropometric measurements at birth (weight, head circumference, length, ponderal index and skinfolds), after correction for differences in gestational age, were significantly related to fetal growth velocity. The relation between fetal growth velocity and ponderal index was significant (correlation coefficient = 0.34, P < 0.001). However, the correlations between fetal growth velocity and each of the anthropometric measures disappeared when birth weight relative to gestational age was accounted for. This means that given the birth weight and the gestational age of a newborn infant, body proportions, e.g. ponderal index or skinfold thickness, do not contribute further to the judgment about fetal growth rate.

Anthropometry

Primacy and recency effects in nonhuman primates.

The reports of primacy and recency memory effects in nonhuman primates have been criticized because they have all used an initiating response. That is, the presentation of the to-be-remembered list of items was always contingent on a response being initiated by the nonhuman primate. It has been argued that this initiating response improves performance for early items in the list, resulting in the occurrence of the primacy effect, independent of any memory processing mechanism. This criticism was addressed in the present study by not using an initiating response prior to the presentation of the list. Nevertheless, both a primacy and a recency effect were observed in all 6 rhesus monkeys evaluated using a serial probe recognition task. Thus, the results are similar to those for humans, in that both primacy and recency effects can be obtained in nonhuman primates. A brief literature review is included, and it is proposed that the primacy and recency effects observed in humans, nonhuman primates, and infraprimates can be explained within the context of the configural-association theory.

Animals

Detection of small-for-gestational-age fetuses by ultrasound screening in a high risk population: a randomized controlled study.

OBJECTIVE: To assess the value of fetal weight estimation during routine third trimester ultrasound examinations for the identification of small-for-gestational-age (SGA) fetuses, to promote active pregnancy management and so reduce perinatal morbidity. DESIGN: A prospective controlled randomized study. SETTING: Outpatient clinic at the Department of Obstetrics, Herlev University Hospital, Denmark. SUBJECTS: One thousand pregnant women considered at risk were selected consecutively from April 1985 to September 1987 and randomized to either a revealed-results group or a withheld-results group. INTERVENTION: All the women had an early ultrasound examination for estimation of gestational age. Both groups had routine ultrasound estimates of fetal weight after 28 weeks and then every third week until delivery. The results were available for clinical use only in the revealed group. MAIN OUTCOME MEASURES: Number of interventions during pregnancy (admission to hospital, elective delivery), emergency intervention during labour, and fetal outcome. RESULTS: Revealing the results of ultrasound estimates of fetal weight for gestational age during the third trimester resulted in statistically significantly increased diagnosis of SGA fetuses, of elective deliveries based on this diagnosis, and of healthy preterm babies admitted to the neonatal care unit, but no detectable overall improvement in weight for gestational age at birth, or in neonatal morbidity or mortality. CONCLUSION: This method of screening improved the diagnosis of SGA fetuses, but this was not followed by improved fetal outcome.

Birth Weight

A new protective solution for hypothermic storage of free vein grafts in cardiovascular surgery.

In order to reduce the operative injury of the endothelium in free reversed vein grafts, cultured human endothelial cells were used to test the optimal concentration of the constituents of a flushing solution for improved protection of the endothelium. The following solution proved to be the most suitable when tested at 20 degrees C; mannitol 160 mmol l-1, glucose 15 mmol l-1, NaCl 30 mmol l-1, KHCO3 5 mmol l-1, K2SO4 10 mmol l-1, KH2PO4 4 mmol l-1, MgSO4 20 mmol l-1, CaCl2 1.5 mmol l-1, potassium citrate 1.0 mmol l-1, Pluronic F-68 20 mg l-1, HEPES 4 mmol l-1, HEPES-Na 6 mmol l-1, pH 7.25, osmolality 325 mosmol kg-1 H2O. When endothelial cell injury was measured by a 51Cr-release assay, the new solution protected human endothelial cells in culture during hypothermic incubation better than isotonic NaCl, St Thomas' cardioplegic solution or Krebs-Henseleit's buffer. Transmission and scanning electron microscopy showed that the endothelium of human saphenous vein grafts was well preserved following 6 h of incubation at 20 degrees C with the new solution. As determined by morphometry using scanning electron microscopy, the endothelium of free porcine vein grafts was better preserved after incubation for 2 h at 20 degrees C with the new solution than with either isotonic NaCl (p = 0.02) or diluted, heparinized blood (p = 0.02) as the incubation medium, all cases observed following 2 h of subsequent arterial flow. The present study indicates that the endothelium of free vein grafts can be well protected against hypothermia when the flushing and irrigation fluid has a composition favouring endothelial protection. It appears likely that such treatment of vein grafts will reduce the frequency of vein graft narrowing and occlusion, post-operatively.

Animals

[Unskilled ultrasound scanning in gynecology and obstetrics can lead to serious risks].

Four cases of ectopic pregnancy were incorrectly diagnosed by ultrasound examination as intrauterine pregnancies. The clinicians involved were biased by the misinterpretation and did not react to the clinical symptoms of ectopic pregnancy. One patient died because of intraperitoneal haemorrhage and some of the other patients were in serious danger. In a fifth case, a midwife examined a pregnant woman with a gestational age of 31 weeks and suspected twin pregnancy. A senior registrar with limited training in ultrasound methods performed an examination and found one foetus. After this examination, the patient was examined clinically on six occasions by midwives and obstetricians but none of these questioned the ultrasound diagnosis. Unfortunately, a twin pregnancy was present. This became apparent when the first twin was delivered and the second twin was in a transverse lie and delivery by Caesarean section was required. The second twin has since developed spastic palsy. These case reports illustrate that young doctors require improved training in ultrasonic diagnostic methods. In addition, clinicians should not rely too much on the results of ultrasound examinations but should also employ their clinical judgement.

Adult

Nutrient digestibilities in ingredients fed alone or in combinations.

Digestibility coefficients (DC) of protein, dry matter, energy, starch, and dietary fibre in individual feedstuffs were used to predict the DC in feed mixtures. Digestibility studies with growing rats involved six feed sources: soya-bean meal, barley, rapeseed meal, peas, wheat bran and wheat, given individually and in various combinations, i.e. fourteen diets in total. True digestibility of protein (TD) and apparent digestibility of starch could be predicted in feed mixtures from their respective DC values for the individual ingredients, except in the diet composed of peas + barley. Dry matter (DM) and insoluble dietary fibre digestibilities in the mixtures could also be calculated from their individual DC values. Energy digestibility could be predicted in all mixtures except for barley + wheat and peas + wheat. Although the discrepancies were significant, the differences were not great. The digestibility of soluble dietary fibre in the mixtures could be predicted as for the individual ingredients in all but three diets: rapeseed meal + barley, peas + barley and peas + wheat. The results confirm that DC values for TD, DM, energy, starch and dietary fibre in mixtures can be calculated with high precision from DC determined from individual ingredients. Caution should be taken though when mixtures contain a high amount of dietary fibre, especially of the soluble type.

Animal Feed

Daily food intake and digestibility in rats.

The present work with growing rats was undertaken to study the effect of daily food intake (DFI) on true protein digestibility (TD), and apparent digestibility of dry matter (DM), energy (DE), starch, soluble dietary fibre (SDF) and insoluble dietary fibre (IDF). The design involved two different dietary combinations, barley + rapeseed meal (diet 1) and oats + wheat bran (diet 2). A slight but significantly negative relationship was seen between DFI and TD on diet 1 while no such relationship was found on diet 2. Although significant, DFI influenced DM digestibility of both diets only slightly. A similar situation could also be seen for the effect of DFI on DE. The digestibility of starch was significantly affected by DFI on both diets even though the lowest values were as high as 0.994. SDF digestibility (fermentability) was not influenced by DFI when the rats were given diet 1, while there was a significant negative effect of DFI on digestibility of SDF when diet 2 was given. The digestibility (fermentability) of IDF was not affected by DFI on either of the two diets. The results confirm the existence of a weak negative relationship between DFI and digestibility of a range of nutrients although the effect seems to be only marginal and of no importance under practical feeding conditions.

Animals

A comparison of aspiration, antazoline sclerotherapy and surgery in the treatment of hydrocele.

Of 98 hydroceles (mean volume 125 ml) in a consecutive series of 92 patients, treated initially by aspiration, 14% (mean volume 70 ml) were cured. The 76 recurring hydroceles (mean volume 146 ml) were then randomised to either antazoline sclerotherapy on an out-patient basis or surgery. Cure rates were 89 and 100%, respectively, at follow-up 6 months later. Operated patients were admitted for a mean duration of 2.5 days. The results indicated that aspiration alone was inadequate, and sclerotherapy is advocated as the first choice of treatment for hydrocele.

Adult

Paroxetine and imipramine treatment of depressive patients in a controlled multicentre study with plasma amino acid measurements.

In a 12-week double-blind study with 36 patients with major depressive episode (DSM-III), paroxetine (Seroxat, Aropax) showed significantly quicker onset of efficacy on the Melancholia Scale, and better tolerance than imipramine. Plasma concentration analyses showed no clear concentration-efficacy correlation in either treatment group. During long-term treatment paroxetine seemed to be superior to imipramine in preventing relapse; both treatments were well tolerated. A significant correlation between baseline plasma tryptophan: large neutral amino acids ratio and final Hamilton Rating Scale for Depression (HRSD) score and a trend towards an inverse correlation between this ratio and percentage reduction in HRSD score were seen in the paroxetine group but not in the imipramine group. In line with previous studies, these results support the hypothesis that paroxetine is an effective and well tolerated antidepressant.

Amino Acids

Occurrence of doxycycline resistant bacteria in the oral cavity after local administration of doxycycline in patients with periodontal disease.

Topical antimicrobial treatment is appearing as a means of therapy in patients with advanced periodontal disease. The purpose of the present study was to examine the occurrence of doxycycline resistant bacteria in subgingival plaque and oral cavity after local administration of doxycycline. Five patients with advanced marginal periodontitis were scaled, and one approximal pocket in each patient was additionally treated with locally delivered doxycycline. Microbiological samples were obtained from the test site, a contralateral control site and tongue and tonsils before treatment and 3, 13, 26 and 52 weeks after treatment. The occurrence and morphological distribution of doxycycline resistant bacteria was determined after anaerobic cultivation on enriched tryptic soy agar with and without doxycycline incorporated. At the test site and on tongue and tonsils the percentage of doxycycline resistant bacteria increased from less than 1% before treatment to 22% and 35%, respectively, immediately after treatment, but decreased again at week 13. At the control site no increase was observed. Gram-positive cocci constituted the majority of doxycycline resistant bacteria at all 3 sampling sites (73-94%). The morphological distribution of resistant bacteria was not affected by the doxycycline therapy. Thus, local doxycycline therapy resulted only in a transient increase in resistance in the oral microflora.

Administration, Topical