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Biomedical subjects

L Svendsen

Publications and source records attributed to L Svendsen.

At least 19 recordsLinked to original sources
PubMed2000

Ultrasound screening in the 2nd trimester. The pregnant woman's background knowledge, expectations, experiences and acceptances.

OBJECTIVE: Ultrasound screening in the second trimester is widely used in maternal health care. To secure the pregnant woman's autonomy, it is essential to obtain information relating to her understanding and wishes as a starting point for the provision of information. The aim of the study was to explore the pregnant woman's background knowledge, expectations, experiences, and acceptances of second trimester ultrasound screening. DESIGN: Five-hundred consecutive, unselected pregnant woman, of gestational age between 16 and 20 weeks were asked to fill in a questionnaire containing defined and open ended questions. RESULTS: Approximately 70% of the women recruited had undergone a pregnancy-related ultrasound examination previously. Ninety percent answered that they had received information, either from the family doctor or as written material from the hospital (or both), concerning the purpose of the examination. Literature/newspaper/TV, family and friends played an important role as sources for general information. The pregnant women wished to undertake the ultrasound examination to ensure that the fetus was alive, healthy and without any malformation. Few answers were clinically irrelevant. The womens' expectations were fulfilled in 96% of cases, 86% felt 'more secure' after the examination while 2% did not have their expectations fulfilled. Only 0.8% felt more insecure after the examination. The vast majority of both pregnant women and their partners reported a positive experience from the event. CONCLUSION: Pregnant women have a good knowledge of ultrasound examination although the quality of information could be improved. Expectations are fulfilled and are clinically relevant. The acceptability and experiences of the examination are very high.

Attitude↗
PubMed1998

Zopiclone as night medication in rheumatoid arthritis.

Sleep disturbances and related daytime complaints are frequent in rheumatoid arthritis (RA). The aim of the current study was therefore to evaluate the effect of a newer hypnotic on sleep structure and clinical parameters in RA. Forty outpatients were randomized to a two week treatment regimen with either 7.5 mg zopiclone or placebo at bedtime. Clinical examinations were performed before and after treatment and the degree of pain, fatigue, sleepiness, morning stiffness, and activities of daily living were assessed. Two sleep questionnaires were also completed weekly. Polysomnography was performed before the study and after 14 days of treatment. Recordings were evaluated using conventional sleep scoring as well as frequency analysis of the electroencephalography (EEG). Patients in the zopiclone group had subjective improvement of sleep, but otherwise no differences in pain score or the other clinical parameters were found. Conventional sleep assessments showed only minor changes during treatment, but frequency analysis demonstrated a shift from the lower towards the higher EEG frequencies in the active treatment group. Although the modulation of the EEG can represent a non-specific pharmacologic epiphenomenon, it might also reflect a disturbance of sleep microstructure. In conclusion, treatment with zopiclone may be of value for subjective sleep complaints in selected patients with RA, but it is doubtful whether hypnotics improve daytime symptoms in this patient group.

Adult↗
PubMed1998

Sleep in rheumatoid arthritis: a comparison with healthy subjects and studies of sleep/wake interactions.

Sleep complaints are frequent in patients with rheumatoid arthritis (RA) and sleep disturbances may contribute to pain and other daytime complaints. The aims of the current study were to compare ambulatory sleep recordings from consecutively selected patients with RA to those obtained in healthy controls, and to study the relationships between sleep structure and clinical symptoms. Sleep recordings were obtained from 41 out-patients with RA and 19 matched controls. All had clinical examinations and completed different questionnaires. Recordings were scored traditionally and, moreover, the electroencephalography (EEG) was subjected to frequency analysis. For the study of sleep-wake interactions in the patients, a graphical chain model was used. The patients had many sleep-related complaints. An increase in the number of periodic movements of the legs (PML) during sleep was seen in comparison with controls, but otherwise only minor differences were observed in classical sleep stages. Data from frequency analysis showed an increase in alpha (8-12 Hz)-EEG activity in sleep stages non-rapid eye movement (NREM) 2-4 in most sleep cycles. The statistical model demonstrated a complex but independent correlation between morning stiffness, pain and joint tenderness on the one hand, and awakenings, stage NREM2, slow-wave sleep and stage REM on the other, probably reflecting a relationship between sleep patterns and pain in RA. In conclusion, only the increase in PML and alpha-EEG activity distinguished the sleep in RA patients from that of healthy controls. However, the demonstrated interaction between daytime complaints and sleep patterns may increase the understanding and treatment of the disease. In future research, graphical chain models may improve our understanding of complex relationships between multiple variables.

Adult↗
PubMed1997

The ability of thrombin inhibitors to reduce the thrombin activity generated in plasma on extrinsic and intrinsic activation.

In a thrombin generation test with continuous registration of thrombin activity in plasma we studied the ability of a variety of thrombin inhibitors of different type and mechanism of action of influence the activity of thrombin after activation of the coagulation system. Depending on the inhibitor, the peak of thrombin activity is delayed and/or reduced. By blocking the active site of generated thrombin inhibitors cause a concentration dependent reduction of the thrombin peak and inhibit feed-back reactions of thrombin resulting in a delay of thrombin generation. Highly potent synthetic active-site directed inhibitors (Ki < or = 20 nM) reduce the thrombin activity formed in plasma after extrinsic or intrinsic activation with the same efficiency (IC50 0.1-0.6 microM) as hirudin. The delay and reduction of thrombin generation by inhibitors of the anion-binding exosite 1 of thrombin is only attributed to an inhibition of feed-back reactions of thrombin. For a 50% reduction of thrombin activity in plasma by this type of inhibitors relatively high concentrations were determined.

Amino Acid Chloromethyl Ketones↗
PubMed1997

Inhibition of thrombin generation in plasma by inhibitors of factor Xa.

A series of inhibitors of factor Xa (FXa) were investigated using the thrombin generation assay to evaluate the potency and specificity needed to efficiently block thrombin generation in activated human plasma. By inhibiting FXa the generation of thrombin in plasma is delayed and decreased. Inhibitor concentrations which cause 50 percent inhibition of thrombin generation (IC50) correlate in principle with the Ki values for inhibition of free FXa. Recombinant tick anticoagulant peptide (r-TAP) is able to inhibit thrombin generation with considerably low IC50 values of 49 nM and 37 nM for extrinsic and intrinsic activation, respectively. However, the potent synthetic, low molecular weight inhibitors of FXa (Ki values of about 20 nM) are less effective in inhibiting the generation of thrombin with IC50 values at micromolar concentrations. The overall effect of inhibitors of FXa in the thrombin generation assay was compared to that of thrombin inhibitors. On the basis of similar Ki values for the inhibition of the respective enzyme, synthetic FXa inhibitors are less effective than thrombin inhibitors. In contrast, the highly potent FXa inhibitor r-TAP causes a stronger reduction of the thrombin activity in plasma than the most potent thrombin inhibitor hirudin.

Animals↗
PubMed1996

Folate and homocysteine status and haemolysis in patients treated with sulphasalazine for arthritis.

In an attempt to estimate the frequency of folate deficiency and haemolysis in a group of 25 outpatients with arthritis treated with sulphasalazine (SASP), haematological measurements, including plasma total homocysteine (tHcy) which is a sensitive marker of folate deficiency, serum folate (S-folate), erythrocyte (RBC) folate, S-cobalamin and routine indices of haemolysis were performed. No patient had been taking folate-containing vitamins for at least 8 weeks prior to the study. Compared to a group of 72 healthy hospital staff, the median plasma tHcy was significantly higher in the patient group (8.8 mumol 1(-1) vs. 6.8 mumol 1(-1); p = 0.003). Five patients (20%) had plasma tHcy levels that exceeded the upper normal limit of plasma tHcy (median+2 SD of the reference group). Median S-folate was significantly lower in the patient group (6.0 nmol 1(-1) vs. 8.5 nmol 1(-1); p < 0.001), and 11 (44%) patients had depressed S-folate. Only three (12%) patients had RBC folate values below the reference interval. There was no difference in the levels of RBC folate between the two groups. A comparison of S-cobalamin levels in the two groups disclosed a significantly lower level in the patient group. However, no patient had cobalamin deficiency as assessed by S-cobalamin and S-methylmalonate measurements. Thus, it is unlikely that any patient had increased plasma tHcy due to cobalamin deficiency. Of 24 patients having a HbA1c measurement performed, 12 (50%) had decreased levels indicating chronic haemolysis. Only seven (28%) patients had reticulocytosis. HbA1c was positively correlated to haptoglobin levels (r = 0.77; p < 0.001) and negatively correlated to the percentage of reticulocytes (r = -0.50; p = 0.02). The percentage of reticulocytes was negatively correlated to haptoglobin levels (r = -0.42; p = 0.04). The chronic haemolysis of the patients' blood due to SASP might explain the similar RBC folate values in the two groups because of a relatively higher folate content of young erythrocytes. In conclusion, our results support previous findings of folate deficiency and haemolysis occurring in a considerable fraction of patients receiving treatment with SASP. Measurements of plasma tHcy suggest that a substantial number of patients may have folate deficiency at the tissue level.

Adolescent↗
PubMed1996

Ambulatory polysomnography using a new programmable amplifier system with on-line digitization of data: technical and clinical findings.

A new system for polysomnographic recording at home is presented. It consists of a 12 to 24-channel amplifier system with direct digitization of the polygraph signals using a portable computer. Sampling frequency, amplification and filter settings can be defined by the user, and the signals are evaluated at bedside. Technical testing proved a high signal/noise ratio, linear amplification and a good signal quality. Clinical testing of the first 100 recordings showed that they were acceptable for conventional sleep scoring in 98 cases. A comparison of two consecutive recordings was done in 9 healthy subjects and 11 patients with rheumatic disorders. Using conventional sleep staging, only a slight "first night effect" (FNE) was demonstrated in the sleep architecture. Power spectral analysis using autoregressive modeling demonstrated only a difference of power between the 2 nights in the beta (14.5-25 Hz) band. In conclusion, the usability and technical advantages make the system very suitable for ambulatory recordings and only a minimal FNE should be considered when results are evaluated.

Adult↗
PubMed1995

[Spiral compter tomography in acute pulmonary embolism].

13 patients with clinically suspected acute pulmonary embolism were assessed by means of contrast-enhanced spiral volumetric computed tomography (CT). Our experience is already so positive that we wish to focus on this method. Spiral CT gives an exact diagnosis in many cases where perfusion scintigraphy is uncertain. In our opinion spiral CT can be reliably used in patients with clinically suspected pulmonary embolism, and appears to offer an alternative to scintigraphy and pulmonary angiography.

Acute Disease↗
PubMed1995

Development and regulation of porcine pancreatic function.

A surgical and experimental procedure was developed to enable the collection of pure and inactivated pancreatic juice during the growth of the pig. Studies have shown that, during the suckling period, both the basal and the secretory responses to suckling are low, if present at all. After weaning, basal levels of the total exocrine secretion, total protein, amylase, and trypsin, respectively, increase slightly, while the postprandial levels of total protein, amylase, trypsin, lipase, colipase, and carboxylester lipase, respectively, increase markedly. The pancreatic juice enzyme composition changes qualitatively and the antibacterial activity of the pancreatic juice also significantly increases. Piglet age appeared to be of minor importance, since weaning at either 4 or 6 wk of age gave the same results. Secretin and CCK administered together in supraphysiological doses only significantly affect exocrine function from 3-4 wk of age. However, CCK may also affect the exocrine pancreas indirectly via reflexes initiated intraduodenally. Milk consumption in the suckling pig leads to a postprandial increase in glucose levels but not insulin. Milk appears to be able to regulate the exocrine pancreas to produce only the amount and type of enzymes required for digestion. Thus, milk components or digestive products may affect pancreas function regulation. Studies show that enterostatin, the procolipase activation peptide, may inhibit pancreatic secretion mediated indirectly through the GI tract. Pancreastatin, an endocrine peptide, inhibits both insulin secretion and protein and trypsin secretion to pancreatic juice. In hypoinsulinemic (alloxan+streptozotocin diabetes) pigs (15-20 kg), no postprandial pancreatic juice response is seen, although CCK 33 + secretin can stimulate pancreatic secretion. Hypoinsulinemic pigs have a reduced capacity for glucose tissue utilization, suggesting that tissue metabolism and exocrine pancreas secretion are related.

Animals↗
PubMed1995

Clustering of sleep electroencephalographic patterns in patients with the fibromyalgia syndrome.

Several electroencephalographic (EEG) abnormalities have been observed during sleep in patients suffering from the fibromyalgia syndrome (FMS). In this study, 12 patients with fibromyalgia and 14 control subjects had two polysomnographic recordings obtained at home. Data from the second night were subjected to blinded manual scoring as well as signal processing using linked or 'step-wise clustering for pattern recognition. In this procedure, a common learning set was generated using the spectral information in three 2 min EEG samples from each of the sleep stages selected from five patients with FMS and five controls. In this way, 17 characteristic EEG classes were defined. All 2 s EEG segments from the whole night from all subjects were then assigned to one of these classes. Five of the classes (dominated by 0.5-4.5 Hz activity) were more frequent in the control group, whereas three other classes (dominated by 8-11 Hz activity) were prevalent in the patient group. This trend was consistent in all sleep stages, although most striking in non-rapid eye movement (NREM) sleep. The predominance of these classes in the patient group may correspond to the alpha-EEG sleep anomaly previously reported in subjects with FMS. More importantly, as the EEG power in the lowest frequency range (prevalent in controls) probably is a marker for restorative sleep, the findings may reflect important aspects of sleep disturbances n subjects suffering from FMS, thereby contributing to some of the daytime symptoms in these patients.

Adult↗
PubMed1995

Sleep intensity in fibromyalgia: focus on the microstructure of the sleep process.

Alpha electroencephalography (EEG) predominance has been described during sleep in patients suffering from the fibromyalgia syndrome (FMS). However, EEG power density in the lower frequency bands probably better reflects the restorative functions of sleep. This study was conducted to describe the energy in all frequency bands in the sleep EEG. Ambulatory sleep recordings were performed on 12 women with FMS and 14 control women. Epochs were classified according to standard criteria. Moreover, all 2-s segments (n = 287,355) of the EEG in non-rapid-eye-movement (NREM) 2-4 sleep were subjected to frequency analysis using autoregressive modelling. Frequency bands were: delta (0.5-3.5 Hz), theta (3.5-8 Hz), alpha (8-12 Hz), sigma (12-14.5 Hz) and beta (14.5-25 Hz). In patients with FMS, there was a predominance of EEG power in the higher frequency bands [two-way analysis of variance (ANOVA), alpha: P = 0.043; sigma: P = 0.004] at the expense of the lower frequencies (ANOVA, delta: P = 0.005; theta: P = 0.008). The same trends were obtained for the individual sleep cycles. The calculations of total delta power in the time domain showed an exponentially declining curve in healthy subjects, but a flatter decline in FMS. The decreased power in the low-frequency range might reflect a disorder in homoeostatic and circadian mechanisms during sleep and may contribute to daytime symptoms in patients with fibromyalgia.

Adult↗
PubMed1995

Effect of oral corticosterone administration on locomotor development of neonatal and juvenile rats.

In order to simulate the elevated corticosteroid levels to which offspring of stressed women may be subjected, rat pups were treated daily with two levels of oral corticosterone from the 2nd to the 15th postnatal day. The rat pups were subjected to swimming tests from their 8th postnatal day to examine their neuromuscular development and learning abilities. The locomotor performance of corticosterone-treated groups was similar to that of controls but its development was delayed, which demonstrates that even relatively low levels of corticosterone have a significant negative influence on the maturation and learning ability of neonatal rat pups. This indicates that the glucocorticoid levels to which suckling neonates (for example, children of women suffering from stress) might be exposed could modify the complex integrated neuromuscular adaptive mechanisms involved in normal locomotor development.

Animals↗
PubMed1995

Development and comparison of purification strategies for chicken antibodies from egg yolk.

With regard for animal welfare as well as cost, antibodies purified from the egg yolk of immunized chickens are an attractive alternative to antibodies raised in serum of mammals. Various purification strategies based on initial purification by a freeze-and-thaw method followed by one of three precipitation methods--ammonium sulfate, polyethylene glycol 6000, or caprylic acid--were compared. Ammonium sulfate precipitation (25 to 40%) was found to give the best combination of high purity and yield (58%). Moreover, this method is inexpensive and well suited for standard purification of egg yolk antibodies in large scale production facilities.

Ammonium Sulfate↗
PubMed1994

Testing garlic for possible anti-ageing effects on long-term growth characteristics, morphology and macromolecular synthesis of human fibroblasts in culture.

The beneficial effects claimed for the use of garlic as a nutritional supplement include detoxification, antioxidation, antifungal activity, antibacterial activity, tumour suppression and, possibly, anti-ageing and rejuvenating effects. We have used the Hayflick system of cellular ageing in culture in order to test garlic for its anti-ageing effects on long-term growth characteristics, morphology and macromolecular synthesis of human skin fibroblasts. Our results show that an addition of garlic extract into the normal cell culture medium can support serial subculturing for over more than 55 population doublings in 475 days, and that this treatment has some youth-preserving, anti-ageing and beneficial effects on human fibroblasts in terms of maximum proliferative capacity and morphological characteristics. In comparison, similar or lesser doses of garlic extracts are growth inhibitory for cancerous cells that could not be grown over longer periods in the presence of garlic. To our knowledge, this is the first report of the effects of garlic on the long-term growth characteristics and macromolecular synthesis of normal human skin cells, the results of which have applications for both anti-ageing and anti-cancer research.

Adult↗
PubMed1994

Quantitative assessment of joint pain following treatment of rheumatoid arthritis with ibuprofen cream.

The antiinflammatory effect of percutaneous application of NSAID (DOLGIT cream) was evaluated quantitatively on 11 patients with symmetric rheumatoid arthritis of the metacarpophalangeal and/or proximal interphalangeal joints. The pressure pain detection threshold (PDT) and pressure pain tolerance threshold (PTT) on the test joints were measured before and on days 3 and 7 after double-blind placebo controlled application of NSAID cream. The clinical pain was assessed by a visual analog scale (VAS) following controlled finger movements. The relative median PDT differences between NSAID and placebo treatment median were 10 kPa (N.S.) on day 3 and 17 kPa (N.S.) on day 7. The corresponding median differences in PTT were -5 kPa (N.S.) and 23 kPa (P < 0.05), respectively. The corresponding median decreases in VAS score were 4.2 mm (N.S.) and 15.5 mm (N.S.), respectively. The experimental joint pressure techniques can assess selectively pain from small joints and is a new useful tool to evaluate antinociceptive and/or antiinflammatory effects.

Administration, Topical↗
PubMed1994

Ambulatory recording and power spectral analysis by autoregressive modelling of polygraphic sleep signals in patients suffering from chronic pain.

A portable digital recording system and the Nightingale sleep analyser have been applied to record polygraphical sleep signals in patients suffering from chronic pain. Using ambulatory recording the patient can sleep at home making the sleep more natural and reducing the costs. The recording system gives digital recordings of very good quality. It is shown that the Nightingale sleep analyser performs automatic sleep analysis with a quality comparable to visual interrater performance on disordered sleep. It furthermore provides means for extraction of spectral information useful for the description of the sleep-wakefulness processes and for diagnosing the sleep disorders. Using AR-model-based power spectral analysis, it is also shown that the power content in the alpha band relative to the delta power is significantly higher in patients suffering from non-specific chronic pain as compared to normal persons.

Chronic Disease↗
PubMed1993

[Chronic pain after spinal cord injury--a descriptive study].

Sixty-three patients with chronic pain following spinal cord injury (SCI) completed a questionnaire about different aspects of pain. Median duration from SCI to first experience of pain was four months. The duration of pain was for a median of three years. Fifty-six percent graded their pain as strong or unbearable. Ninety-two percent of the patients had daily pain, and in 43% the pain was constant day and night. The pain seriously affected daily living in 38% and sleep was disturbed in 48%. The pain had worsened in 43% and improved in 16% since its start. No association was found between performed spinal surgical procedures and the intensity of pain, the course of the pain, the time from SCI till pain started or the size of the area of pain. The most frequently used words to describe pain were "stabbing" and "tingling". This study documents the severity and course of chronic pain following SCI.

Adolescent↗