| 1. |
- Blomström-Lundqvist, Carina, et al.
(författare)
-
Effect of long term treatment with metoprolol and sotalol on ventricular repolarisation measured by use of transoesophageal atrial pacing
- 1986
-
Ingår i: British Heart Journal. - 0007-0769. ; 55:2, s. 181-186
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of long term (4 weeks) treatment with oral metoprolol (100 mg twice daily) and sotalol (160 mg twice daily) on ventricular repolarisation time were compared in a double blind crossover study in 20 patients post-infarction. For QT interval studies transoesophageal atrial pacing was performed at a cycle length of 800 ms. Sotalol prolonged the QT interval by 5-7% compared with metoprolol. The prolongation reflects a change in the repolarisation time because there was no change in the QS interval. Measurements of heart rate at rest and during bicycle exercise indicated that metoprolol and sotalol in the doses selected were equipotent as beta blockers. Transoesophageal atrial pacing is a simple non-invasive method with few and mild side effects that is well suited to drug studies.
|
|
| 2. |
- Blomström-Lundqvist, C, et al.
(författare)
-
Quantitative analysis of the signal-averaged QRS in patients with arrhythmogenic right ventricular dysplasia
- 1988
-
Ingår i: European Heart Journal. - 0195-668X .- 1522-9645. ; 9:3, s. 301-312
-
Tidskriftsartikel (refereegranskat)abstract
- Temporal signal averaging of the surface QRS (VI + V3 + V5) was performed in 16 patients with arrhythmogenic right ventricular dysplasia and in 16 normal subjects. The differences between ARVD patients and normals were large for the filtered QRS duration (FQRSd) (146.2±18.9 vs. 91.8±4.1ms, P<000001), the late potential duration (LPd) (83.5±23.3 ms vs. 23.6±4.6ms, P< 0.00001), the LPd/ FQRSd ratio (53.9± 10.1% vs. 25.8±5.1%, P <0.00001), the filtered QRS amplitude (234.0±61.1μV vs. 429±942 fiV, P <0001), and the root mean square voltage of the signals in the terminal 40 and 50 ms of the FQRS (RMS40 and RMS50) (18.4± 10.0μV vs. 118.4±49.8p.V, P<0.0005 and 27.9± 19.2μV vs. 217.0±66.3fiV, P<0000002). RMS50 <40μV discriminated best between ARVD and normals (81% sensitivity and 100% specificity). The right-sided predominance of the abnormalities in ARVD was demonstrated by the significantly longer FQRSd and LPd, and the higher ratio LPd/FQRSd in right than in left precordial leads. The arrhythmia susceptibility did not seem to influence the presence of or properties ofLP in the ARVD group. Patients with multiple QRS morphologies during ventricular tachycardia (VT) had, compared with patients with only one type of VT, longer LPd (108.3 ±46.4 ms vs. 64.2 ±31.7 ms, P<0.02) and lower RMS40 voltage (9.4±9.9 μV vs. 25.4±21.6 μV, P<0.05). The relative heart volume was positively correlated with delayed activity, but an enlarged heart was not apre-requisitefor the presence ofLP. The method thus identifies changes which are specific to ARVD. The findings indicate that certain electrical or morphological conditions are required for the occurrence of arrhythmias.
|
|
| 3. |
- Hirsch, Jan M, et al.
(författare)
-
The reversibility of the snuff-induced lesion : an experimental study in the rat
- 1986
-
Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 15:10, s. 540-543
-
Tidskriftsartikel (refereegranskat)abstract
- Snuff lesions were induced in 30 rats. Ten of the snuff-exposed rats were killed immediately after 13 months snuff exposure, as were the 10 control animals. Ten rats were killed 1 month and 10 rats 4 months after the snuff administration had ceased. The rats exposed to snuff for 13 months exhibited hyperplastic, hyperorthokeratotic epithelium with focal mild atypia, focal ulcerations and marked subepithelial fibrosis. These changes were markedly reduced or absent in rats exposed to snuff and killed after a snuff-free interval of 1 or 4 months. Similar differences between the test-groups were seen in the epithelium lining the gingival sulcus of the lower incisors. This area seems to be more sensitive to chemical exposure than the oral mucosa proper as more severe microscopical changes were seen here. Snuff exposure results in the development of a hyperplastic, reactive, reversible lesion of the oral mucosa, suggesting that snuff predominantly has promoting activity when administered for a relatively short interval of time.
|
|
| 4. |
- Johansson, S L, et al.
(författare)
-
Snuff-induced carcinogenesis : effect of snuff in rats initiated with 4-nitroquinoline N-oxide
- 1989
-
Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 49:11, s. 3063-3069
-
Tidskriftsartikel (refereegranskat)abstract
- A canal in the lower lip to function as a reservoir for snuff was surgically created in 150 male Sprague-Dawley rats. The animals were randomized into five groups of 30 each: Group I received snuff twice a day, 5 days a wk; Group II was painted with propylene glycol (solvent control) on the hard palate 3 times a wk during 4 wk; Group III underwent painting on the hard palate with 4-nitroquinoline N-oxide (4-NQO) dissolved in propylene glycol, 3 times a wk for 4 wk; Group IV received 4-NQO as in Group III followed by snuff application as in Group I; and Group V received a cotton pellet dipped in saline twice a day, 5 days a wk. Treatment continued for up to 108 wk. There was no significant difference in mean survival time between the groups. Squamous cell tumors of the lip, oral and nasal cavities, esophagus, and forestomach were seen only in Groups I, III, and IV. Nine tumors of these organs were found in Group I (six carcinomas and three papillomas), nine in Group III (seven carcinomas and two papillomas), and ten in Group IV (eight carcinomas and two papillomas). The difference between each of these groups and the control groups (II and V) with regard to tumor incidence is statistically significant (P less than 0.05). In Group I, four oral cavity or lip carcinomas were found in 29 rats, a significant difference in relation to control rats (P less than 0.05). In addition, hyperplastic lesions of the lip, palate, and forestomach were significantly more common in Groups I and IV compared with Groups II, III, and V. The study has shown that snuff and 4-NQO by themselves have the potential to induce malignant tumors. Initiation with 4-NQO followed by snuff did not significantly enhance tumor formation.
|
|
| 5. |
- Larsson, P A, et al.
(författare)
-
Effects of acyclovir on herpes simplex virus type 1 infection in mice treated with 12-O-tetradecanoylphorbol 13-acetate
- 1989
-
Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 70:7, s. 1773-1778
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to determine whether infectious herpes simplex virus type 1 (HSV-1) has tumorigenic properties and, if so, whether inhibition of the cytolytic replicative cycle of the virus after infection enhances tumour development. Eighty mice were subjected to repeated inoculation of HSV-1 on their upper lips after scarification, and systemic administration of acyclovir (ACV). 12-O-tetradecanoylphorbol 13-acetate (TPA) was used as the tumour promoter. The tumour incidence was compared to control groups each of 40 mice that were either not treated with ACV, not treated with TPA, not infected with HSV or only scarified. In the virus-infected group treated with ACV and TPA, 25% of the animals developed tumours. In the HSV-infected group treated with TPA only, 25% of the animals also developed tumours. The uninfected animals which were not treated with TPA developed tumours to a significantly lesser degree. In conclusion, the combined effects of HSV-1 and TPA, with or without ACV treatment, resulted in a significant increase in the number of tumours in comparison to the control groups.
|
|
| 6. |
- Larsson, P A, et al.
(författare)
-
Snuff tumorigenesis : effects of long-term snuff administration after initiation with 4-nitroquinoline-N-oxide and herpes simplex virus type 1
- 1989
-
Ingår i: Journal of Oral Pathology & Medicine. - : Wiley. - 0904-2512 .- 1600-0714. ; 18:4, s. 187-192
-
Tidskriftsartikel (refereegranskat)abstract
- The tumor promoting effects of snuff was studied in Lewis rats initiated with 4-nitroquinoline-N-oxide (4-NQO) and Sprague Dawley rats repeatedly inoculated with herpes simplex virus type 1 (HSV-1). The test substances were administered in a surgically created canal in the lower lips of the rats. There were 15 rats in each test group and 10 rats in the control group. In the groups treated with 4-NQO and 4-NQO + snuff, 8 and 12 tumors (5 and 9 malignant) were found, respectively. In the group subjected to HSV-1 only, 3 tumors were found (2 malignant), in the group subjected to snuff only, 4 tumors were found (3 malignant) and in the group subjected to the combination of HSV-1 and snuff, 13 tumors were found (7 malignant). In the control group only one malignancy was found. The study did not show any promoting effects of snuff in the oral cavity after initiation with 4-NQO. Neither was there any increase in the number of oral tumors in rats treated with HSV-1 and snuff. However, there was a marked increase in the number of malignant tumors outside the oral cavity in the group treated with HSV-1 and snuff, underlining the importance of interactions between these two agents in the development of malignant lesions.
|
|
