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Biomedical subjects

B Lindström

Publications and source records attributed to B Lindström.

At least 127 records · Page 7Linked to original sources
PubMed1982

Rehabilitative procedures in sensorineural hearing loss. Studies on the routine used.

The effect of different treatment programs in audiological rehabilitation was evaluated. The speech intensity at which subjects with high frequency hearing loss correctly perceived 50% of the key words in sentences was measured in quiet and in noise, with and without a hearing aid and with and without simultaneous speech reading. No statistically significant difference in audiovisual speech perception ability was found between subjects receiving no training, subjects receiving a 6-hour information course, or a 3-week intensive training in auditory and audiovisual speech perception. Large differences in the degree of hearing aid usage was found, however, between the three treatment groups. An analysis of the individual results from the speech test used showed that some subjects improved with the use of a hearing aid, whilst others deteriorated. The degree of hearing aid usage was considerably influenced by the measured effect of the hearing aid treatment. Our findings stress the need for an objective test by which to measure the effect of hearing aid fitting. As a result of the reported study a series of experiments have been started with the aim of obtaining a better understanding of the audiovisual speech perception process. These studies are based on an information-processing model for speech perception. Particular attention is devoted to the importance of the prosodic information in the auditory speech signal.

Adult↗
PubMed1982

A comparative study of metronidazole and sulfasalazine for active Crohn's disease: the cooperative Crohn's disease study in Sweden. I. Design and methodologic considerations.

The design and execution of the Cooperative Crohn's Disease Study in Sweden are described in this paper. A double-blind, double-dummy, crossover (2 X 4 mo) technique was used to compare the suppressive efficacy of metronidazole (0.4 g b.i.d.) and sulfasalazine (1.5 g b.i.d.). The number of randomized patients (78) presented approximately one-third of the available population. The Crohn's Disease Activity Index and the plasma level of orosomucoid were the main variables for clinical evaluation. Results were analyzed primarily in the first treatment period by ranking the clinical outcome of every patient according to a uniform and detailed scheme and applying Wilcoxon nonparametric statistics. The cross-over data only served as additional information. Thirty-six patients had had earlier and mostly positive experience with sulfasalazine. Repeated plasma drug analysis indicated good compliance. The blindness of the trial was tested and appeared satisfactory. The coordination of the trial proceeded as planned. A lack of full conformity in the electroimmunoassay of orosomucoid was taken care of satisfactorily.

Adult↗
PubMed1982

A comparative study of metronidazole and sulfasalazine for active Crohn's disease: the cooperative Crohn's disease study in Sweden. II. Result.

Seventy-eight patients with active Crohn's disease participated in a randomized, double-blind, cross-over trial. The study comprised two 4-mo period. The purpose was to test the efficacy of metronidazole in comparison with that of sulfasalazine. As the main evaluation criteria the Crohn's Disease Activity Index and plasma levels of orosomucoid were chosen. In the first period no difference in efficacy as measured by Crohn's Disease Activity Index was found between the treatment groups. The reduction of the plasma orosomucoid level was significantly more pronounced in the metronidazole group. The hemoglobin concentration increased more in this group than in the sulfasalazine group, possibly due to a toxic effect of sulfasalazine. The erythrocyte sedimentation rate decreased similarly with both drugs. In 15 patients who had active disease throughout the first period, Crohn's Disease Activity Index decreased significantly in the second period for those who switched to metronidazole, but not for those who switched to sulfasalazine. After crossover, no apparent further change in Crohn's Disease Activity Index occurred in either of the treatment groups among patients who had responded favorably in the first period. The plasma concentration of orosomucoid increased significantly among the patients in the sulfasalazine group but not in the metronidazole group. It is therefore concluded that metronidazole is slightly more effective than sulfasalazine in the treatment of crohn's disease. It is worthwhile switching the drug regimen from sulfasalazine, when it fails, to metronidazole, but not from metronidazole to sulfasalazine.

Adult↗
PubMed1981

[Long-term treatment of virilized women with cyproterone acetate (author's transl)].

76 women with virilizing features (68 women suffering from hirsutism and 8 from acne) were treated on average for 25 months according to different models of Androcur medication. Success of treatment was clinically assessed as good in 3/4 of the cases and slight in the remaining 1/4. However, treatment is more successful in cases of adrenal hirsutism than in idiopathic hirsutism. Moreover, success of treatment seems to be better in women below 35 than over 35 years of age. Side effects, mostly bleeding anomalies and fatigue, were found in 31 women; these must be attributed to the gestagenic component of cyproterone acetate. By contrast, 12 women showed positive side effects such as weight reduction, improvement in depression states and reversal of hair loss, which must be attributed to the antiandrogenic component. The selected continuation rate in all subjects was 86% and the unselected 72%, over a treatment period of 4.5 years. Furthermore, hormonal controls were carried out under treatment. These showed, on average, a depression of plasma androstendione of 17%, of total plasma testosterone of 47%, as well as an inhibition of the testosterone/sex hormone-binding globulin quotient of 58%. These inhibition effects speak in favour of alterations taking place in steroid metabolism. However, by inhibition of androgenic serum levels, the mechanism of cyproterone acetate is only assisted, while the main mechanism is based on peripheral receptor inhibition. Furthermore, as additional component in this action a slight increase in plasma binding capacity was found during combined cyproterone-oestrogen treatment.

Acne Vulgaris↗
PubMed1981

Extractive alkylation of 6-mercaptopurine and determination in plasma by gas chromatography-mass spectrometry.

An analytical procedure was developed for the determination of 6-mercaptopurine in plasma. Owing to the polar character and low plasma concentration of the compound, extraction and derivatization was carried out directly from the plasma sample by extractive alkylation. Determination was made using gas chromatography-mass spectrometry with multiple-ion detection. Conditions with respect to the rate of formation and the stability of the derivative formed in the extractive alkylation step were evaluated. The selectively of the method to azathioprine and to metabolites was thoroughly investigated. No 6-mercaptopurine was formed from azathioprine added to water or plasma and run through the method. The method enables the detection of 2 ng of 6 mercaptopurine in a 1.0-ml plasma sample. Quantitative determinations were done down to 10 ng/ml 6 mercaptopurine in plasma.

Alkylation↗
PubMed1981

Combined treatment with sustained-release theophylline and beta2-adrenoceptor-stimulating agents in chronic childhood asthma.

The effect of adding theophylline to treatment with a beta2-adrenoceptor stimulant was studied in 18 asthmatic children in a double-blind cross-over trial. Most patients were taking cromolyn sodium (cromoglycic acid) or beclomethasone aerosol, or both. A sustained-release preparation of theophylline was administered in individually titrated doses, producing a mean plasma theophylline concentration of about 8 micrograms/ml. Statistically significant improvements were found during the theophylline treatment in symptom score, consumption of beta2 stimulants in aerosol form, and morning peak expiratory flow rate and forced expiratory volume in one second. There was also a reduced need for emergency-room treatment during the theophylline period. Reported side effects were few and mild and were similar during the theophylline and placebo periods. Of the 17 patients who completed the trial, 14 preferred theophylline and three expressed no preference between theophylline and placebo. Adding submaximal doses of sustained-release theophylline to treatment with a beta2 stimulant gave further relief of asthmatic symptoms without appreciable side effects, suggesting that the drug combination has a favourable therapeutic index.

Adolescent↗
PubMed1981

Prazosin kinetics in hypertension.

Prazosin kinetics were studied after single doses (intravenous and oral, 0.5 mg) and after increasing multiple doses (0.5 to 5 mg three times daily) in eight patients with hypertension. After intravenous administration the kinetics could be described by a linear two-compartment open model. Terminal half-life (t1/2 beta) was about 3 hr and apparent volume of distribution (Vd beta) about 0.6 l/kg. After oral doses bioavailability ranged between 55% and 82%. Since total plasma clearance was low (0.14 l/kg x hr) incomplete bioavailability was the result of incomplete absorption rather than of first-pass liver metabolism. The estimated extraction ratio was about 14%. Renal clearance was negligible; only 1% to 2% of the dose was recovered unchanged in urine. Binding to plasma proteins to both albumin and alpha 1-acid glycoprotein was substantial (97%), with albumin being most important. Increasing multiple doses showed that prazosin followed first-order kinetics with a linear correlation between dose and steady-state plasma concentration (P less than 0.001). There were substantial variations in plasma concentrations between patients and there were also day-to-day variations in concentration within the same patient.

Adult↗
PubMed1981

Prazosin dynamics in hypertension: relationship to plasma concentration.

The antihypertensive effects of prazosin in relation to its kinetics were studied after single doses (intravenous and oral, 0.5 mg) and during increasing multiple doses (0.5 to 5 mg three times a day). There was a fall in systolic and diastolic blood pressures of 10% to 14%, which was greater in the standing than in the sitting position. Prazosin plasma concentrations correlated with dose (P less than 0.001). After intravenous prazosin the fall in systolic and diastolic blood pressure and prazosin plasma concentration correlated (P less than 0.01) during the beta-elimination phase in all patients. In only five of eight patients, however, did mean plasma concentration and antihypertensive effect during continuous treatment with different doses correlate. The maximal fall in systolic blood pressure correlated (P less than 0.01) with that after the first oral steady-state dose (0.5 mg three times daily), which indicates limited possibility of early identification of prazosin responders. There were no signs of overshoot of blood pressure when prazosin was withdrawn for a week. On rechallenge with a single oral dose of 2.5 mg prazosin there were no signs of enhanced hypotensive effect.

Adult↗
PubMed1981

Studies of thyroid hormone and methimazole levels in patients with Graves' disease on a standardized anti-thyroid drug regimen.

The outcome of a standardized carbimazole (CMI) regimen was evaluated in fifty-four patients with Graves' disease. Triiodothyronine (T3) and thyroxine (T4) serum values were determined before and throughout the first 6-8 months of therapy. Before therapy, decreasing T4/T3 ratios were found with increasing T3 levels, reflecting a relative increase in T3 production compared with T4 in thyrotoxicosis. High pretreatment T3 values were comparatively common among patients in whom a fixed CMI dosage had a insufficient effect. T4 levels were less informative in this respect. Serum levels of methimazole (MMI), the active metabolite of CMI, were dose-dependent. A 50% reduction in dosage resulted in a similar decrease in the serum values. For a give dose, the MMI levels differed considerably among individuals. The variation was not related to thyroid hormone values. It appears that the response to the anti-thyroid drug is primarily dependent upon the severity of the disease, Which is clearly reflected in serum T3 levels, rather than individual differences in drug handling. A routine CMI regimen for the treatment of thyrotoxicosis is suggested.

Adolescent↗
PubMed1981

Relation between concentrations of metronidazole and Bacteroides spp in faeces of patients with Crohn's disease and healthy individuals.

Nine patients wih Crohn's disease and six healthy individuals were given 400 mg metronidazole twice daily and the concentration was measured in plasma and faeces 6 to 8 h after intake. Quantitative and qualitative bacteriological examinations were performed before and during treatment. The concentrations of metronidazole in plasma varied between 5 and 30 mg/l as measured by liquid chromatography (LC) and between 3 and 20 mg/l as measured by a bioassay (BA) method. There was no significant differences between the results of the two methods in patients but compared with BA the LC values were regularly lower in the healthy subjects. Metronidazole was detected in the faeces of most patients. These findings coincided with a significant reduction of Bacteroides spp in their faeces which was not apparent in healthy individuals in whom metronidazole was not detected in the faeces. Higher faecal metronidazole concentrations were found in patients with active disease and a total colon involvement as compared with the patients with a more quiescent disease and involvement of ileum and ascending colon only.

Adolescent↗
PubMed1981

On the use of click-evoked electric brainstem responses in audiological diagnosis. III. Latencies in cochlear hearing loss.

The basis for the use of click-evoked BSER in neurotologic differential diagnosis would seem to be its sensitivity to retrocochlear but relative resistivity to cochlear lesions. The present study was performed in order to investigate the presumed robustness of BSER in cochlear hearing loss by recording BSER in 110 consecutive cochlear ears with click thresholds not in excess of 60 dB HL. There were eleven ears with rising, twenty-two ears with flat, and 77 ears with sloping audiograms. Click intensities were 80 dB HL and 60 dB SL, and the BSERs were observed for replicability and latencies of waves I, III and V, as well as for I-V and III-V interpeak intervals. Wave V latency increments (relative to normal values) were related to hearing thresholds at 4 kHz. Wave V was identifiable in all of the ears at 80 dB HL and/or 60 dB SL, whereas waves I and III often failed to appear at 80 dB HL and occasionally at 60 dB SL. At 80 dB HL click level, the wave V latency increment was related to the 4 kHz hearing loss (statistically significant at level 0.05 in the HF loss group), increasing by approximately 0.1 ms for each 10 dB, starting at 30 dB HL. Increasing click intensity to 60 dB SL tended to bring waves I and III into appearance and to offset the V latency increase (even inverting it in highly recruiting flat loss ears). Interpeak intervals were not significantly affected by cochlear hearing loss. Unfiltered alternating clicks were used after two initial experiments had shown that nothing would be gained in this study from using filtered clicks or uniphase unfiltered clicks.

Adolescent↗
PubMed1981

On the use of click-evoked electric brainstem responses in audiological diagnosis. IV. Interaural latency differences (wave V) in cochlear hearing loss.

Interaural latency differences (ILDs) of wave V of the brainstem electric response (BSER) were studied (1) in 20 normal-hearing subjects at 90, 80, 60 and 40 dB HL click level, (2) in 22 patients with symmetrical cochlear hearing loss at 90 dB HL, corresponding to 45-80 dB SL, and (3) in 45 patients with asymetrical cochlear hearing loss with interaural recruitment, at 90 dB HL on one hand and at a click sensation level corresponding to 90 dB HL in the poorer ear (range 10-75 dB SL) on the other hand. In the normal hearing group the ILDs did not exceed 0.2 ms except in one case at 40 dB HL (0.3 ms). In the symmetrical cochlear loss group the ILD did not exceed 0.2 ms in any patient. In the asymmetrical cochlear loss group the ILD at 90 dB HL exceeded 0.2 ms in 12 cases, but only in four cases after correction for pure tone hearing loss at 4 kHz by 0.1 for each 10 dB above 50 dB HL; at equal sensation levels the ILDs were all zero or negative meaning that the wave V latency was shorter on stimulation of the poorer ear. Assuming ILD to be a valid discriminator between cochlear and retrocochlear lesions, the corrected ILD at equal click hearing levels (90 dB HL), with the critical value set at 0.2 ms, thus gave a 9% false-positive rate whereas the ILS at equal sensation levels, with the critical value set at zero, gave no false-positives. It still remains to be shown that the latter criterion will not increase the number of false-negative results in retrocochlear lesions.

Adult↗
PubMed1981

Kinetics of indoprofen in patients with renal insufficiency (a preliminary report).

Plasma and urinary indoprofen concentrations were determined by liquid chromatography in healthy subjects and two patients with reduced glomerular filtration rate (GFR) of about 25 ml/min. The plasma half-life of the drug was prolonged in renal insufficiency. Until further studies have been performed indoprofen should be used with care in patients with renal impairment. Tentatively, the size of the dose or interval should be adjusted in proportion to the estimated preserved GFR.

Administration, Oral↗