Evaluation of the ‘stretched pore phenomenon’ in isolated rat hindquarters

RIPPE, B., HARALDSSON, B., FOLKOW, B. 1985. Evaluation of the ‘stretched pore phenomenon’ in isolated rat hindquarters. Acta Physiol Scand 125 , 453–459. Received 5 March 1985, accepted 7 May 1985. ISSN 0001–6772. Department of Physiology, University of Göteborg, Sweden. In order to study the changes in capillary permeability occurring upon marked elevations in microvascular pressure, capillary filtration coefficient (CFC) and diffusion capacity (PS) for Cr-EDTA were repeatedly measured ‘on-line’ before and after brief periods (3 min) of large venous pressure (P_v) elevations in maximally vasodilated perfused rat hindquarters. First at P_v's ≥ 55 mmHg, increases in CFC and Ps-Cr-EDTA were observed immediately after the pressure elevations. While the CFC increases were then always pronounced (up to 4- to 5-fold), the concomitant increases in PS-Cr-EDTA were small (at most 30–40%). For P_v≥ 55 mmHg there was a rough proportionality between P_v and CFC. While PS for Cr-EDTA showed little reversibility with time upon P_v normalization, CFC was usually almost completely reversed after 10–20 min. The mentioned CFC and PS increases at P_v's ≥ 55 mmHg were quantitatively similar to those induced by histamine-type mediators in the same preparation. It is concluded that capillary hydraulic conductivity can increase markedly but reversibly upon large P_v elevations, and that this is mainly due to forceful opening of ordinarily closed ‘large pores’ in the microvascular membrane, rather than being caused by lesional rifts in the endothelium,     

Prevalence of factor V gene mutation amongst myocardial infarction patients and healthy controls is higher in Sweden than in other countries

Objective. Haemostatic imbalance may be an aetiological factor in the development of acute coronary syndromes. Inherited resistance to activated protein C (APC) is a common disorder associated with hypercoagulability and lifelong risk of venous thrombosis. APC resistance is due to a single mutation in the gene coding for coagulation factor V (FV:Q⁵⁰⁶). To test the importance of the FV:Q⁵⁰⁶ mutation in premature myocardial infarction (MI), its prevalence was investigated in Swedish patients with MI before the age of 50 years.
Design, setting and subjects. In a retrospective case-control study, the FV:Q⁵⁰⁶ mutation was investigated in 101 survivors of MI (79 men, 22 women) and in 101 healthy sex- and age-matched controls.
Main outcome measure. The prevalence of FV:Q⁵⁰⁶ mutation.
Results. The FV:Q⁵⁰⁶ mutation was found in 18% of patients versus 11% of controls ( P =0.16). The mutation was significantly more frequent amongst male patients than amongst controls (23 vs. 10%; P =0.03), the calculated odds ratio being 2.6 (95% CI, 1.1–6.4).
Conclusion. The high prevalence of the FV:Q⁵⁰⁶ mutation found amongst Swedish MI patients, especially amongst men, is noteworthy, and calls for further studies on the outcome of MI in APC-resistant patients. The prevalence of the FV:Q⁵⁰⁶ mutation in controls is higher than figures reported from other countries, suggesting that at least 10% of the Swedish population are carriers of a congenital prothrombotic disorder.     

Length of Consultations in General Practice in Sweden: Views of Doctors and Patients

In a study in Sweden of 160 consultations, general practitionersand patients separately assessed their satisfaction with theconsultation length and the ability of the patient to explainthe problem. These assessments were compared with each otherand were correlated with the actual length of the consultation.The mean length of the consultations was 21 minutes with a greatvariation between different doctors. Consultations with psychologicalproblems were longer than those with a physical character (meanof 28 versus 14 minutes). Elderly patients had longer consultations.The patients were on the whole more satisfied than the doctors.There was no evidence that longer consultations gave more satisfactionfor either doctors or patients. The doctors not only registeredmore psychological problems than the patients but they weremore likely to register insufficient time for discussing psychologicalproblems.     

Attitudes Towards Predictive Testing in Huntington's Disease-A Deep Interview Study in Sweden

Ten persons with a 50% risk of inheriting Huntington's diseasewere interviewed in depth about experiences of the disease withspecial regard to their attitude to a predictive test. The personsshowed great interest, concern and worry about a test: six weregenerally positive while four were negative or uncertain. Everyinterview had a very personal character and early life experiencesseemed to have a determinative influence on the attitude tothe test. Persons who were without symptoms of the disease andhad passed the mean age of onset within the family (usuallyolder individuals) were largely enthusiastic about a test, aswere those with slight and undetermined symptoms. Younger persons,especially those with a qualitatively good contact with theaffected parent, seemed to be less interested. Contradictionsduring the interview were more common among those positive totesting and an ambivalence among many was reflected in a tendencytowards changing opinions over time.     

Uremic Polyneuropathy: Different Effects of Hemodialysis and Continuous Ambulatory Peritoneal Dialysis

ABSTRACT. Registrations of clinical signs of neuropathy, quantified according to a fixed protocol, and determinations of vibratory perception thresholds and nerve conduction velocities (NCV) were performed in 22 patients treated with hemodialysis (HD) and in 21 patients treated with continuous ambulatory peritoneal dialysis (CAPD). Measurements were made at the start of dialysis and during a follow-up period of about 30 months. Motor NCV decreased in both groups; vibratory thresholds increased markedly in the CAPD patients, but not in the HD patients; and the clinical signs worsened in the HD patients, but not in the CAPD patients. The difference in outcome of the clinical signs during HD and CAPD was not of such a magnitude that one of these dialysis forms should be preferred before the other as regards neuropathy. We conclude that peripheral neuropathy may deteriorate during both HD and CAPD, but in significantly different ways, indicating that several pathogenetic mechanisms are probably involved in uremic neuropathy.     

Musculoskeletal Disorders in Shipyard Workers

The primary hypothesis was that musculoskeletal disorders weremuch more common in older workers than in younger ones. A questionairewas answered by 1565 shipyard workers at a health check-up.We also scrutinized diagnoses from the health centre at theshipyards. The work load of each occupation was independentlyestimated in three degrees, low, moderate and heavy. There wasno obvious relation between musculoskeletal disorders and age.However, there was as expected a strong relationship betweenwork load and symptoms or medical diagnoses. The data indicatedno strong correlation between musculoskeletal disorders fromdifferent organs. Requests for reprints should be addressed to: Bengt Järvholm, Department of Occupational Medicine, S.t Sigfridsgatan 85, S-412 66 Göteborg, Sweden     

Structural and functional ontogenetic development of the rat portal vein after neonatal 6-hydroxydopamine treatment

The importance of the adrenergic vasomotor nerve supply for the vascular ontogenetic development has been studied in the isolated portal vein preparation from rats, at 5–6 weeks of age, who had either been chemically sympathectomized by a series of postnatal 6-hydroxydopamine (6-OHDA) injections or been receiving the solvent alone. It was found that 6-OHDA treatment largely, but not completely, prevented the outgrowth of the terminal NA fluorescent ground plexus. Nevertheless, the media underwent a seemingly normal differentiation into two layers. Functionally, the portal vein from the 6-OHDA treated animals displayed weak and non-persistent myogenic spontaneous activity; sensitivity to exogenous noradrenaline (NA) was increased 3-fold and maximum stress was increased by 25 % as compared to control. Responses to transmural field stimulation were only obtained at high impulse rates and the maximum response was attenuated. Considering the very sparse adrenergic innervation following 6-OHDA they seemed surprisingly large, however, but since they were abolished by tetrodotoxin and by phenoxybenzamine responses are concluded to be neurogenic and adrenergic in origin. A singular attenuation of neurogenic responses by atropine was found in 6-OHDA treated vessels but not in controls. It is concluded that the adrenergic vasomotor nerve supply seems to exert some trophic influence during ontogenetic development but that the morphologic vascular development is largely governed by other, non-neurogenic mechanisms. As to functional development, 6-OHDA induced sympathectomy causes impaired development of phasic myogenic activity whereas maximum stress is augmented as is the tissue sensitivity to exogenous NA.