Biomedical subjects
Publications and source records attributed to G Svensson.
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The technique of balloon catheter dilatation of benign esophageal strictures is presented. A general anesthetic is unnecessary which is an advantage in older patients. Moreover, the encouraging results and the absence of complications support the opinion that balloon catheter dilatation is an excellent alternative in the treatment of esophageal strictures.
Nude athymic rats of Rowett genetic background were injected subcutaneously with cells from a poorly differentiated human pulmonary adenocarcinoma, following propagation in nude mice. The tumour cells were obtained by thoracentesis and by pleural biopsy during thoracoscopy. So far, we have heterotransplanted 13 different malignant human tumours including malignant mesothelioma, pulmonary adenocarcinoma, malignant melanoma and malignant lymphoma. Subcutaneous tumour growth was seen in all inoculated animals, with an exponential tumour growth pattern and with tumour volume doubling times of approximately 8 days. After two initial passages in nude athymic mice of BALB/c genetic background, the human tumour so far has undergone 9 passages in athymic rats, i.e. collection of tumour material by biopsy from the preceding tumour-bearing rat generation, processing and inoculation of tumour brei with subsequent tumour growth have been repeated 8 times. Four-to-8-week-old rats of both sexes were used throughout and tumour growth was controlled by palpation twice a week. Routine histopathological sections were prepared from the tumour at various passages to assess similarity to the original tumour in the patient. The growth pattern of the xenografts remained similar at all passages just as the remarkable similarity of the heterotransplanted tumours to the original adenocarcinoma was retained at all passages. No spontaneous regressions of heterotransplanted tumours could be demonstrated. Electron microscopical analysis revealed numerous blunt microvilli and lumina partly filled with conglomerates of mucigen granules and small glycocalyceal bodies associated with external superficial microvilli. Scantiness of dark secretory granules together with free and membrane-bound polyribosomes were seen in the cytoplasm. We believe that the nude athymic rat is a valuable research tool and that the permanently transplantable human tumour reported here could be of value in delineating further the mechanisms for tumour take, growth and control.
The antiarrhythmic effects of tocainide, administered as a bolus injection of 750 mg followed by oral therapy, and conventional lidocaine therapy were evaluated in 40 patients admitted for suspected acute myocardial infarction (AMI) and showing high-grade premature ventricular complexes (PVCs). The mean hourly PVC rate before therapy was 928 and its reduction was equally significant in the tocainide group, 73%, and in the lidocaine group, 68%. The number of 5-minute periods with multiform, paired and R/T PVCs or ventricular tachycardia was also significantly reduced, by 78% in the tocainide group and by 71% in the lidocaine group. Ten patients in the tocainide group reported moderate side-effects, compared to 13 in the lidocaine group, where the infusion had to be discontinued in 5 patients and the rate had to be reduced in 4. Tocainide, an amine analogue of lidocaine, is considered just as effective as lidocaine in patients with high-grade PVCs and suspected AMI.
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Previous studies of immotile cilia syndrome have shown airway obstruction. The aim of this study was to analyse lung function in such patients before severe chronic obstruction had occurred. Spirometry, lung volumes, pulmonary resistance and static pressure volume diagram were studied in six patients (ages 21-43 years). Closing capacity, the volume of trapped gas and the slope of the alveolar plateau were determined with N2 wash-out tests. Regional ventilation was studied with a gamma camera after inhalation of 99Tcm-tagged dry aerosol. Arterial blood gases were determined at rest and during exercise. Bronchial reactivity was studied with FEV1 before and after inhalation of methacholine aerosol. Five of six patients showed a rather uniform pattern, dominated by signs of "small airway disease" seen in e.g. volumes of trapped gas and closing capacity. Those five patients had uneven ventilation scintiscans and bronchial hyperreactivity. Spirometric findings and lung mechanics were influenced by lung resection, scoliosis and by the lability of bronchial tone. Five patients had normal arterial blood gases at maximum work load. Working capacity was essentially normal in all but one patient, who had a high degree of obstruction. Immotile cilia syndrome is thus compatible with a comparatively well preserved lung function and a normal working capacity far into adult life.
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A flow injection method for the determination of ammonia in whole blood and plasma is described. The method utilizes diffusion of ammonia into a stream of a pH-sensitive indicator, which is monitored by a photometer. A volume of 90 microliter is needed and the result is obtained within 1 min. Ammonia concentrations increase during storage due to deamination. It is proposed to use plasma samples, which could be stored frozen at - 20 degrees C without significant change.
During 4 weeks of the grass pollen season in the south of Sweden 27 patients with seasonal allergic rhinitis were treated topically with a beta-adrenoceptor stimulant, KWD 2131, which in an earlier rhinomanometric study had shown a prophylactic effect at nasal allergen provocations in hay-fever patients. A clinical effect of KWD 2131 could not be documented in this randomized placebo-controlled, double-blind comparative study. The results contribute to conclusions in the clinical implications of rhinomanometric data.
The nasal airway resistance in various positions of the body was investigated in 24 patients with perennial non-allergic rhinitis and in 10 normal subjects. No difference in nasal airway resistance between inspiration and expiration was found. the patients had higher resistance than the controls, a difference providing an anatomical explanation of their complaint of nasal obstruction. When the patients changed from the recumbent to the sitting position, the resistance did not decrease until after about one hour. The corresponding time for the controls was 10 minutes. This difference suggests that oedema is a more important cause of nasal swelling in the patients than in normal subjects. Local treatment of the patients' nasal mucosa with terbutaline revealed no clear oedema-reducing effect to the drug.
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The effects of the beta-adrenoceptor stimulating drugs, terbutaline (Bricanyl) and KWD 2131, on the increase in nasal airway resistance induced by pollen extracts, have been studied in a placebo-controlled double-blind crossover trial of 13 asymptomatic (out of season) patients with hay fever. For objective evaluation of the nasal airway resistance posterior rhinomanometry has been used. The rhinomanometric measurements indicated an antianaphylactic effect of terbutaline and KWD 2131, but rhinoscopy and the patients' own opinion could not establish such an effect. The design of the trial made it possible to establish whether or not an increased or a decreased nasal obstruction due to repeated challenges occurred. Despite 6 preceding nasal provocations in each participant, neither increased ('priming effect') nor decreased (hyposensibilization) reaction was detected in the following challenge.