Biomedical subjects

T Larsen

Publications and source records attributed to T Larsen.

At least 91 records · Page 5Linked to original sources

PubMed1993

Dephytinization of a rat diet. Consequences for mineral and trace element absorption.

Soaking of a rat diet, high in both plant phytate and phytase, progressively degraded the phytate content with time of soaking. This dephytinization in turn enhanced the digestion of feed organic matter in the animals, and it significantly improved the absorption and retention of minerals and trace elements as observed in balance studies. Incorporation of elements into specific tissues was evaluated as a reflection of bioavailability. Some tissues did reflect the preceding absorption of certain elements; other tissues seemed less suitable as indicators of trace element absorption. Dietary calcium addition in many ways contrasted the soaking procedure: inorganic calcium addition to the feed reduced phosphorus, magnesium, and trace element bioavailability, and interfered with the internal deposition of the elements. The external dephytinization of the feed did not affect the phosphohydrolase activity of the intestinal mucosa as manifested by alkaline phosphatase activity or phytase activity. The mucosal phytase and alkaline phosphatase activities were, however, mutually correlated, supporting the view that "phytase" activity is a less substrate-specific action of alkaline phosphatase activity or a fraction of this activity.

6-Phytase↗

PubMed1993

Running induces menstrual disturbances but bone mass is unaffected, except in amenorrheic women.

PURPOSE: To investigate the prevalence of exercise-related menstrual and sex hormonal disturbances and the effect of exercise on bone mass and metabolism in female runners at various training levels. SUBJECTS AND METHODS: Two hundred five premenopausal women (running 0 to 140 km a week) were recruited from a large population of female runners who had responded to a questionnaire regarding exercise habits. Maximum oxygen uptake was determined by treadmill testing. Gynecologic status was assessed on entries in a menstrual calendar and by transvaginal ultrasonography; sex hormonal status was measured three times with 10-day intervals. Bone mass was measured in the lumbar spine, proximal femurs, and total body by dual-energy x-ray absorptiometry, and in the forearm by single-photon absorptiometry. Bone turnover was assessed by measurement of plasma osteocalcin, serum alkaline phosphatase, and urinary calcium and hydroxyproline. RESULTS: Sex hormonal disturbances were significantly related to training intensity. Compared with the normally active women, the baseline levels and fluctuations of estradiol and progesterone in the elite runners were reduced by up to 25% to 44% (0.01 < p < 0.05). The prevalence of amenorrhea increased from 1% in the normally active subjects to 11% in the elite runners. No statistically significant relation was found between running activity and bone mineral measurements or bone turnover. However, the group of amenorrheic runners had a 10% reduction in lumbar bone density as compared with the normally menstruating runners (p < 0.05), but the bone turnover was similar. CONCLUSION: In the large majority of the female runners, no skeletal affection was found despite significant sex hormonal and menstrual disturbances. Only the runners with amenorrhea might be at increased risk of osteoporosis.

Adult↗

PubMed1993

Abdominal ultrasound combined with histological and cytological fine needle biopsy of suspected ovarian tumors.

To investigate, in a population of women suspected of an ovarian mass, whether pelvic ultrasound (US) and US combined with US-guided fine needle biopsy (FNB) increased the detection rate and whether tumor specific diagnoses could be obtained, a cohort of 307 patients suspected of an ovarian mass underwent US examination as part of routine gynecologic work-up. In cases of solid or solid/cystic lesions a US guided FNB for histology as well as cytology was proposed. All 35 primary ovarian cancers, 6 of 7 secondary ovarian cancers, and 3 of 4 non-ovarian cancers were demonstrated on US. Among 17 cases with normal palpation and an ovarian mass on US, operation disclosed 3 ovarian cancers. FNB identified 24 of 27 primary ovarian cancers and 7 of 7 cancers of extra-ovarian origin. The use of US, in this study, increased the detection of masses in the pelvis and FNB provided a reliable verification.

Abdomen↗

PubMed1993

Effect of dietary calcium level on mineral and trace element utilization from a rapeseed (Brassica napus L.) diet fed to ileum-fistulated pigs.

The bioavailability of intrinsic minerals in rapeseed (Brassica napus L.) meal was studied in growing, fistulated pigs. Furthermore, the effect on mineral availability of an extrinsic Ca supply to this diet, high in phytate, was observed. Comparisons between small intestinal and total gastrointestinal absorption were accomplished for minerals and other dietary components. N retention increased as the dietary Ca intake increased, but dropped, in general significantly, throughout the experimental period, indicating that factors other than protein were limiting for growth. The highest dietary Ca level increased the absorption and retention of Ca and Mg. In contrast, addition of CaCO3 did not influence the apparent absorption and retention of P, Fe, Zn, Cu and Mn. The majority of observed blood variables was not affected by the Ca content of the diet. Zn status-related variables were, however, thoroughly depressed by duration of the experiment and it seems probable that the amount of absorbed Zn was a factor limiting growth. Total gastrointestinal balances showed a Zn retention of 4.7 mg/d, which accounted for 13.6% of that ingested. This low absorption of Zn may have been due to the high intrinsic content of phytate. Apparent absorption of organic matter, ash, N and S was significantly greater calculated from faecal contents than from ileal contents, indicating a disappearance of material in the caecum-colon section of the gastrointestinal tract. The minerals which were studied showed the opposite pattern:apparent small intestinal absorption was larger than total intestinal absorption, suggesting that the caecal-colon region takes part in mineral turnover.

Animals↗

PubMed1993

High dietary calcium level decreases colonic phytate degradation in pigs fed a rapeseed diet.

The degradation of phytate (inositol hexaphosphate) in rapeseed meal diet not containing phytase activity was studied in 15 growing ileum-fistulated pigs. Stomach and small intestinal degradation and total gastrointestinal degradation were compared. The effect of addition of calcium carbonate to the rapeseed meal diet at two levels (9.2 and 18.5 g/kg diet) was investigated. A commercial barley-wheat-soybean diet with intrinsic phytase activity was used as reference. Phytate and its hydrolysis products in diets, ileal digesta and feces were determined by HPLC ion-pair chromatography. Hydrolysis of phytate in the stomach and small intestine was 35-45% in pigs fed the rapeseed meal diet independent of calcium addition, and 65% in pigs fed the reference diet. Total gastrointestinal degradation of phytate in pigs fed the rapeseed diet was 97, 77 and 42% (P < 0.001) when calcium intakes were 4.5, 9.9 and 15 g/d, respectively; total gastrointestinal degradation was 72% in pigs fed the reference diet. The intestinal phytate degradation pattern, when rapeseed diet was fed, indicated the activity of an unspecific phosphatase, whereas that of the reference diet indicated intrinsic dietary phytase activity. We conclude that dietary supplementation of calcium carbonate decreases the phytate degradation in the colon of pigs, but not in the stomach and small intestine.

Animals↗

PubMed1993

No effect of single dose ofloxacin on postoperative infection rate after first-trimester abortion. A clinical, controlled trial.

In a double-blind stratificated, placebo controlled study the efficacy and safety of a single oral dose of ofloxanin (Tarivid) (400 mg) in preventing postabortal pelvic inflammatory disease (P-PID) in women with induced first-trimester abortions were assessed. The tablets were given 1 1/2-2 h before the abortion, and the women were followed one month after the operation. Group I consisted of 308 with previous PID. Ofloxacin tablets were given to 149 women and 159 women received placebo tablets. In the ofloxacin group 20 women (13.4%) and in the placebo group 27 women (17%) developed P-PID, a non-significant difference (p = 0.39). Group II consisted of 765 women without a history of PID. Ofloxacin tablets were given to 376 women and 389 women received placebo tablets. Thirty-five women (9.3%) in the ofloxacin group and 46 women (11.9%) in the placebo group developed P-PID, a non-significant difference (p = 0.26). A single oral dose of ofloxacin (400 mg) did not reduce the incidence of P-PID either among women with previous PID or among women without previous PID.

Abortion, Induced↗

PubMed1993

Priority worksheet brings order to information systems projects.

"Eeeny, meeny, miny, moe, and the first priority is ..." maybe the CEO's pet project or nursing's necessity. Putting aside "gut feel" for an objective method promises to streamline the process of prioritizing I/S projects, according to Saint Alexis Hospital Medical Center leadership.

Decision Making, Organizational↗

PubMed1992

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↗

PubMed1992

[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↗

PubMed1992

[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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗

PubMed1992

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↗