Posterior ponticles and rotational stenosis of vertebral arteries. A pilot study using Doppler ultrasound velocimetry and magnetic resonance angiography

Objective To determine whether the presence of posterior ponticles markedly increases by 30% or more, the incidence of major rotational stenosis of vertebral arteries. Methods Doppler ultrasound studies were performed in 3 private chiropractic clinics and in the radiology department of a public hospital, and magnetic resonance angiography (MRA) studies were made in the latter location. Thirty-two chiropractic patients had Doppler velocimetery, and 16 of these patients had MRA scanning. The outcome measures included changes in Doppler velocimetry signals and MRA images indicative of marked rotational stenosis of vertebral arteries. Results All vertebral arteries from the 32 patients displayed no signs indicative of marked rotational stenosis. Conclusion The findings of this study show that the incidence of major rotational stenosis of vertebral arteries is not markedly increased by the presence of posterior ponticles

Vertebral arteries and cervical rotation: Modeling and magnetic resonance angiography studies

Objective: To determine whether lumen narrowing in vertebral arteries during atlanto-axial rotation is due to stretch or localized compression. Design and Setting: Experiments with models were made in a private chiropractic clinic, whereas studies of cadaveric specimens were performed in an anatomy laboratory. Doppler ultrasound and magnetic resonance angiography (MRA) studies were carried out in the radiology department of a public hospital. Patients: Eight patients had their vertebral arteries examined by use of a Doppler velocimeter and MRA. Main Outcome Measure: Stenosis of the vertebral arteries caused by stretch, localized compression, or kinking. Results: All 16 vertebral arteries from the 8 patients displayed no changes in their lumen dimensions with full cervical rotation, although curves in each of the arteries did change. The model and cadaveric vertebral arteries demonstrated localized compression or kinking of the vessel wall with atlanto-axial rotation contralaterally but revealed no evidence of major contribution of stretching to stenosis. Conclusion: The lumen of vertebral arteries is usually unaffected by atlanto-axial rotation. In cases where there is stenosis, this is mainly due to localized compression or kinking. These findings are relevant to premanipulative screening of vertebral arteries with Doppler ultrasound scanning

Diversidade dos noctuídeos (Lepidoptera, Noctuidae) em Salvador do Sul, Rio Grande do Sul, Brasil Diversity of owlet-moth (Lepidoptera, Noctuidae) in Salvador do Sul, Rio Grande do Sul, Brazil

<abstract language="eng">Diversity of owlet-moth (Lepidoptera, Noctuidae) in Salvador do Sul, Rio Grande do Sul, Brazil. The purpose of this paper is to describe the Noctuidae community in Salvador do Sul, Rio Grande do Sul. Light traps captured the insects of this research. The quantitative data were collected through weekly sampling, during one year (1994-1995); the qualitative data were collected through non-systematic sampling, during four consecutive years. The community characterization was based on the richness, abundance, specific constancy, diversity indices and abundance distribution; also total richness estimates were calculated, by nonparametric statistical procedures. In the systematized collecting there were captured 4017 noctuids of 108 species, distributed in 14 subfamilies; in the non-systematized, another 189 additional species and two subfamilies. Amphipyrinae, Hadeninae and Ophiderinae had the largest species richness. The more constant species were noctuids of great economic importance; the accessories were related to specific vegetable groups; the accidentals have their host unknown. The accessories and accidental species were captured more in spring and summer; also in these periods were measured the highest values of richness, abundance and diversity. There was no fit between observed/calculated log normal and log series distribution models. The 2nd order Jackknife and Michaelis-Menten equation procedures estimated that the total richness values were close to the total number of the species in the studied area