PubMed Health⌕ Search

Biomedical subjects

R Eriksson

Publications and source records attributed to R Eriksson.

At least 19 recordsLinked to original sources
PubMed2000

Monitoring cellular state transitions in a production-scale CHO-cell process using an electronic nose.

An electronic nose is used to monitor the bioreactor off-gas composition in perfused cultivations of a CHO-cell line producing recombinant human blood coagulation factor VIII. The applicability of the electronic nose for monitoring cellular state transitions and process control is explained. It is shown that the instrument can reveal characteristic process states related to product and lactate formation, and detect microbial infections in a very early stage of the infection. The visualization of ideal process conditions is realized by using principal component analysis (PCA) and the on-line applicability of this method is outlined. The results illustrate the potential of the electronic nose as on-line sensor for ensuring product and process quality in production-scale bioprocesses.

Animals↗
PubMed2000

The effect of isoniazid on BCG-induced toxicity in patients with superficial bladder cancer.

The use of bacillus Calmette-Guérin in the treatment of transitional cell cancer of the bladder has caused concern because of its associated adverse effects. We conducted a randomized prospective, double-blind, multicentre study to determine whether isoniazid prophylaxis could reduce BCG-induced toxicity without compromising its immunotherapeutic effects. Patients (n = 160) with histologically documented urothelial cancer (pTa-T1, pTis, G1-3) were treated with 6 weekly instillations of BCG Connaught strain, 81 mg, administered concomitantly with a 3-day course of isoniazid (300 mg o.d.) or placebo. Side-effects were recorded with each treatment and at follow-up. Of the patients treated with isoniazid, 19% remained free from side-effects, compared with 16% of the placebo group. Local side-effects confined to the bladder were significantly lower among those receiving isoniazid (35% vs. 48%, p < 0.01). Local side-effects together with systemic adverse effects such as fever, nausea or skin rash were experienced by 30% of patients in each arm. There were no differences in tumour recurrence between the two patient groups. Concomitant isoniazid reduces the local, but not the systemic side-effects of topically applied BCG without compromising the antitumour effect on superficial, transitional cell cancer of the bladder during a follow-up period that now exceeds 2 years.

Administration, Intravesical↗
PubMed1997

Ultrasound Doppler vector tomography measurements of directional blood flow.

An experimental system has been developed to verify the possibility of detecting flow activity using a technique called ultrasound Doppler vector tomography. A tomography algorithm is used to reconstruct blood flow vector fields using data from computer-controlled ultrasound continuous-wave Doppler scanning equipment. The result is a picture in which the brightness variations represent the reconstructed values of the curl of the velocity field (inverted delta x v). Continuous ultrasound is transmitted into a region with flow activity and the Doppler-shifted signals are received. To obtain measurement data suited for fan beam tomography, the scanning is performed in a plane from points encircling the region. Reconstructions have been achieved using measurement data from two different flow phantoms. A comparison between the experimental results and simulations shows good conformity.

Blood Circulation↗
PubMed1995

Blood perfusion measurement with multifrequency Doppler ultrasound.

Due to its sensitivity to measurement artifacts, the ultrasonic Doppler technique has not yet become a clinically useful tool for blood perfusion measurements. One of these measurement artifacts is caused by ultrasonic wave interference in combination with the small changes of structures inside the ultrasonic field. These changes are a result of variations in blood pressure, small movements in muscles, and involuntary movements of the transducer. The changes alter the ultrasonic interference pattern, causing fluctuations in the measured perfusion value. In this paper a new multifrequency technique for blood perfusion measurement is presented. The technique is based on a multifrequency setup, with four ultrasonic frequencies simultaneously transmitted with the same transducer. It is shown that by averaging the measured values obtained from each frequency, the sensitivity to ultrasonic wave interference can be lessened. Measurement results from both in vitro and in vivo experiments are presented.

Artifacts↗
PubMed1991

Evaluation of Doppler ultrasound for blood perfusion measurements.

The need to develop clinical methods for the noninvasive monitoring of regional blood perfusion, i.e., the blood flow through the very fine capillaries in body tissue, has long been felt. Hitherto existing methods exhibit limitations, such as insufficient measurement depth and poor time- or space-resolution, which restrict the measurements that can be performed. Dymling (1982) introduced a new CW Doppler ultrasound method for noninvasive blood perfusion measurement which might be one possible solution to this problem. Preliminary experiments indicated a correlation between blood flow and measured perfusion value. Unexpectedly large variations in the recorded perfusion values lead to further investigation of the method, both in vitro using a specially designed flow phantom and in vivo. This study indicates that at least some of the large variations recorded are the result of measurement errors caused by movement artifacts or ultrasonic signal interferences. Methods to diminish the effects of these artifacts are discussed.

Artifacts↗
PubMed1990

Effect of long-term trace element supplementation on blood trace element levels and absorption of (75Se), (54Mn) and (65Zn).

A vitamin and trace element supplement containing recommended dietary amounts or "safe and adequate" levels was given to ten healthy subjects for 12 to 35 weeks. Plasma levels of selenium and zinc, activity of glutathione peroxidase in plasma and platelets, whole blood manganese, activity of superoxide dismutase in hemolysate, activity of alkaline phosphatase in serum, iron status indices and urinary excretion of zinc and selenium were measured. A small but significant change in plasma selenium from 1.01 +/- 0.14 mumol/L to 1.08 +/- 0.10 mumol/L was observed after two weeks. However, at the end of the supplementation plasma selenium levels did not differ from the initial levels. Plasma glutathione peroxidase levels showed a similar trend and changes in glutathione peroxidase activity in platelets were also transient. A small increase in serum zinc values was observed after 30 weeks of supplementation. No significant changes were observed in the other blood and urine parameters studied. In seven of the subjects absorption of zinc, manganese and selenium was measured after 30-31 weeks of supplementation by a radionuclide technique. The absorption of selenium and manganese after long term supplementation was 30-50% lower than observed previously in non-supplemented subjects. In conclusion, present available indices of trace element status are only to a limited extent affected by 30 weeks of a doubling of the normal dietary intake.

Absorption↗
PubMed1990

Selenium status and absorption of zinc (65Zn), selenium (75Se) and manganese (54Mn) in patients with short bowel syndrome.

Selenium level and activity of glutathione peroxidase in plasma were studied in seven patients with extensive short bowel resection due to Crohn's disease, before and during 27-54 weeks of intake of a vitamin and trace element supplement containing 50 micrograms of selenium as sodium selenite. Initial levels of selenium were normal in all except one of the patients. The supplementation had no or minor effects on plasma selenium levels and glutathione peroxidase activity. The absorption of zinc, manganese and selenium was measured with a radionuclide technique before and/or after the supplementation period in five of the patients. The absorption of zinc and manganese was similar to that observed earlier in healthy subjects, while the absorption of selenium was significantly lower. The results indicate that a higher selenium intake or a different form of selenium is needed in these patients to compensate for the impaired bowel function.

Adult↗
PubMed1987

Retention of selenium (75Se), Zinc (65Zn) and manganese (54Mn) in humans after intake of a labelled vitamin and mineral supplement.

The whole body retention of 75Se, 65Zn, and 54Mn after intake of a labelled vitamin and mineral supplement was followed in 12 healthy volunteers. The supplement had a vitamin and mineral content according to recommended dietary allowances or the so-called "safe and adequate levels" for trace elements, including 15 mg of zinc as zinc citrate, 50 micrograms of selenium as sodium selenite and 2.5 mg of manganese as manganese sulphate. The supplement was taken either in the fasting state or together with a light meal. Retention day 14 was 48 +/- 6%, 33 +/- 6% and 5 +/- 2% (mean +/- SD) for selenium, zinc and manganese, respectively, when the supplement was taken fasting and 45 +/- 3%, 8 +/- 1% and 1.0 +/- 0.2% when it was taken with food. During day 1-14, 27%, 1% and less than 0.01% of the administered selenium, zinc and manganese radionuclides, respectively, were excreted in the urine. Based on the rate of turnover of the radionuclides and the urinary losses of 75Se, the absorption of selenium, zinc and manganese from the supplement was estimated to be 89 +/- 5%, 38 +/- 7%, 9 +/- 3% (mean +/- SD) in the fasting state and 87 +/- 4%, 10 +/- 2% and 2 +/- 1% with food. These results indicate that when a supplement is taken with food the minerals are absorbed and metabolized in the same way as are native minerals in food. When the supplement is taken in the fasting state, the absorption of zinc and manganese can be substantially higher.

Absorption↗
PubMed1986

Evaluation of possibilities for mass screening for colorectal cancer with Hemoccult fecal blood test.

Data from a health survey including the Hemoccult fecal blood test, together with official cause-specific death rates, were used to assess the magnitude of a controlled trial that would be required to prove a 25 percent reduction of the mortality from colorectal cancer associated with screening. All men in three age groups in the city of Malmö, Sweden, were invited, but 46 percent did not participate in, the Hemoccult screening. One carcinoma and 89 adenomas were detected in 56 of the 2422 who did. With the risk function used in our calculation and a compliance rate of 60 percent, a study population among 45- to 69-year-olds of 605,000 is required to prove an expected 25 percent reduction of the mortality with 90 percent power. Considering the size of such a trial, we question whether a controlled trial is feasible. With known risk functions for death from all causes and death from colorectal cancer, the study population was calculated using variable statistical power, participation rate, and risk reduction. Statistical methods and computer programs are given. In addition, alternative study models to assess the benefits associated with screening are discussed.

Adenoma↗
PubMed1982

Theophyllines three times daily - when are the doses actually taken? - Pharmacokinetic ideals versus clinical practice.

We asked patients "At what times of the day do you usually take your medicine?" In contrast to compliance interviews dealing with missed doses, this question was previously shown to give valid information. Here we present results from 126 patients on theophyllines three times daily, the most common dosage schedule for these drugs in Sweden in 1978. Only 2% of the patients stated the ideal 8-h intervals between all doses, while 72% had confined all their doses within 12 h. The first and second intervals ranged from 0 to 11 h with a mean of 5.5 and 6.1 h respectively. The third interval varied from 7 to 18 h with a mean of 12.4 h. Patients might benefit more from their therapy by even-spacing of their intake of theophylline.

Adolescent↗
PubMed1982

Primary fracture immobilization as a method to prevent post-traumatic pulmonary changes- an experimental model.

Post-traumatic pulmonary insufficiency or "respiratory distress syndrome" (RDS) is one of the most feared complications of severe trauma. The aetiology is probably multifactorial, and is obscure. Although modern treatment has reduced the mortality, there is no certain way of preventing the syndrome. The aim of the investigation was to develop an experimental model on anaesthetized pigs subjected to trauma and folllowed up for 3-4 days, still under anaesthesia, the repeated lung X-rays and post-mortem naked-eye and histological examination of lung tissue. 26 pigs were used. 12 (Group I) were subjected to missile trauma of a limb, with a fracture that was left without immobilization. 10 were treated similarly but with immobilization of the fracture (Group II). Four control animals were prepared and observed under anaesthesia but no trauma was inflicted (Group III). In Group I, all but two developed, 10-70 h after the injury, roentgen and morphological changes identical to those seen in patients with clinically documented RDS. No such changes were seen in the controls or in Group II. With our experimental model it seems possible to induce in experimental animals roentgen and morphological changes corresponding to RDS in man. The method provides new means of studying the mechanisms behind and the effects of different forms of treatment in RDS. The results also support the hypothesis that early immobilization of fractures is an important step in preventing RDS.

Animals↗