Seasonal Dynamics of Atlantic Herring (Clupea harengus L.) Populations Spawning in the Vicinity of Marginal Habitats

Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February–June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March–April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May–June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal habitat. The 1.85 km2 lake was characterized by oxygen depletion occurring between 2.5 and 5 m depth between March and June. This was followed by changes in salinity from 1–7‰ in the 0–1 m surface layer to levels of 20–25‰ deeper than 10 m. In comparison, outside the 3 km long narrow channel connecting the lake with the neighboring fjord, no anoxic conditions were found. Here salinity in the surface layer increased over the season from 10 to 25‰, whereas deeper than 5 m it was stable at around 35‰. Temperature at 0–5 m depth increased significantly over the season in both habitats, from 7 to 14°C outside and 5 to 17°C inside the lake. Despite differences in peak spawning and utilization of the lake habitat between the three putative populations, there was an apparent temporal and spatial overlap in spawning stages suggesting potential interbreeding in accordance with the metapopulation concept

Postangioplasty restenosis: a practical model in the porcine carotid artery

Transluminal coronary angioplasty is a routine therapeutic intervention in coronary heart disease. Despite the high rate of primary success, restenosis continues to be its major limitation. Porcine models have been considered to be the most adequate experimental models for studying restenosis. One limitation of porcine models is the need for radiological guidance and the expenses involved. The objective of the present study was to adapt an experimental model of angioplasty in the porcine carotid artery that does not require radiological equipment. Eight animals were used to develop the technique of balloon injury to the common carotid artery by dissection without radiological guidance. This technique was then employed in six other animals. Under anesthesia, the left common carotid artery was dissected and incised at the carotid sinus for insertion of an over-the-wire angioplasty balloon towards the aorta. Overstretch injury of the carotid artery was performed under direct visualization. After 30 days, the arteries were excised and pressure-fixated. Uninjured carotid arteries from 3 additional animals were used as controls. A decreased luminal area associated with intimal hyperplasia and medial reaction was observed in all injured arteries. Immunohistochemistry identified the intimal hyperplastic cells as smooth muscle cells. Computerized morphometry of the ballooned segments revealed the following mean areas: lumen 2.12 mm2 (± 1.09), intima 0.22 mm2 (± 0.08), media 3.47 mm2 (± 0.67), and adventitia 1.11 mm2 (± 0.34). Our experimental model of porcine carotid angioplasty without radiological guidance induced a vascular wall reaction and permitted the quantification of this response. This porcine model may facilitate the study of vascular injury and its response to pharmacological intervention

Sex differences in investigations and outcomes among patients with type 2 myocardial infarction

Objectives Type 2 myocardial infarction (MI) is a heterogenous condition and whether there are differences between women and men is unknown. We evaluated sex differences in clinical characteristics, investigations and outcomes in patients with type 2 MI. Methods In the Swedish Web based system for Enhancement and Development of Evidence based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) registry, we compared patients admitted to coronary care units with a diagnosis of type 1 or type 2 MI. Sex-stratified Cox regression models evaluated the association with all-cause death in men and women separately. Results We included 57 264 (median age 73 years, 65% men) and 6485 (median age 78 years, 50% men) patients with type 1 and type 2 MI, respectively. No differences were observed in the proportion of men and women with type 2 MI who underwent echocardiography and coronary angiography, but women were less likely than men to have left ventricular (LV) impairment and obstructive coronary artery disease (CAD). Compared with type 1 MI, patients with type 2 MI had higher risk of death regardless of sex (men: adjusted HR 1.55 (95% CI 1.44 to 1.67); women: adjusted HR 1.34 (95% CI 1.24 to 1.45)). In those with type 2 MI, the risk of death was lower for women than men (adjusted HR 0.85 (95% CI 0.76 to 0.92) (men, reference)). Conclusions Type 2 MI occurred in men and women equally and we found no evidence of sex bias in the selection of patients for cardiac investigations. Patients with type 2 MI had worse outcomes, but women were less likely to have obstructive CAD or severe LV impairment and were more likely to survive than men