Vascular dysregulation in normal-tension glaucoma is not affected by structure and function of the microcirculation or macrocirculation at rest: a case-control study.

In normal-tension glaucoma (NTG), optic nerve damage occurs despite a normal intraocular pressure. Studies implicating systemic blood pressure or, more recently, arterial stiffness in the pathophysiology of NTG have produced conflicting results. Our aim was to investigate whether NTG is associated with alterations in the macrocirculation or microcirculation, cardiac function, and peripheral and central hemodynamics. Thirty patients with NTG (mean age 65 years, range 46-79) and 33 healthy subjects (mean age 67 years, range 42-79) matched for age and sex were included in the study. Exclusion criteria (for both cases and controls) were history of cardiovascular disease, diabetes mellitus, severe hypertension, and hypercholesterolemia. Aortic stiffness was measured using carotid-femoral pulse wave velocity (PWV), central hemodynamics using carotid artery applanation tonometry, and diameter, stiffness, and intima-media thickness (IMT) of the carotid and femoral artery using echo-tracking. Total peripheral resistance index (TPRI) was derived from mean arterial pressure and cardiac index, measured using ultrasound. There were no statistically significant differences in arterial structure nor function between NTG patients and age and sex-matched controls. NTG versus controls, respectively: brachial blood pressure 126 ± 15/77 ± 8 versus 127 ± 16/76 ± 7 mm Hg, P = 0.81; carotid-femoral PWV 9.8 ± 2.1 versus 10.1 ± 1.9 m/s, P = 0.60; TPRI 1833 ± 609 versus 1779 ± 602 dyne.s/cm5/m2, P = 0.79; and carotid IMT 0.65 ± 0.14 versus 0.68 ± 0.13 mm, P = 0.39. This study could not show an association of NTG with altered IMT, arterial stiffness, total peripheral resistance, cardiac output, and peripheral or central hemodynamics at rest. Although the majority of these NTG patients do exhibit symptoms of vascular dysregulation, in the present study this was not translated into alterations in the microcirculation or macrocirculation at rest.

Asymmetry in prevalence of femoral but not carotid atherosclerosis.

OBJECTIVE(S): Atherosclerotic disease is caused by a combination of systemic and local factors (e.g. geometry) affecting local flow conditions. In contrast to the carotid artery, at the iliac-femoral artery region, a large degree of bilateral asymmetry exists. Therefore, we aimed to determine the influence of body side on the prevalence of atherosclerosis (i.e. plaque and intima-media thickness; IMT) at the carotid and femoral arteries. METHODS: Data were used from the ASKLEPIOS study, including 2524 apparently healthy individuals with a mean age of 46 years (range 35-55 years). Echographic images were obtained bilaterally of the carotid and femoral arteries. A single observer approach was used for the acquisition and quantification of plaques and IMT. RESULTS: The carotid artery displays no significant left-right difference in IMT values nor plaque prevalence (right: 12.0 vs. left 13.3%; P = 0.18). In contrast, for the femoral artery, the IMT distribution at the right common femoral artery is more skewed (P90 right: 1.11 mm, left 1.01 mm; P < 0.001), which is mirrored by a significantly higher plaque prevalence (right: 21.9 vs. left: 15.7%; P < 0.001). CONCLUSION: In the present study, atherosclerotic lesions are more prevalent at the right than at the left femoral artery. This finding highlights the possible role of local arterial geometry in the development of atherosclerosis and underscores the importance of the choice of body side when assessing vascular health.

Noninvasive assessment of carotid-femoral pulse wave velocity: the influence of body side and body contours.

BACKGROUND: Recently, an expert group advised to measure carotid-femoral (cf) pulse wave velocity (PWV) on the right side of the body, and to use a sliding caliper when tape measure distance cannot be obtained in a straight line. The present study investigates the evidence for this advice by comparing the real travelled cf path lengths (RTPLs) at both body sides and comparing the straight distance (as can be obtained with a sliding caliper) with the tape measure distance. METHODS: RTPLs were measured with MRI in 98 individuals (49 men, age 21-76 years). Path lengths from the aortic arch to the carotid (AA-CA) and femoral (AA-FA) sites were determined. RTPL was calculated as (AA-FA) - (AA-CA) and compared between both sides. RTPLs were compared with 80% of the direct cf distance using a tape measure and the straight cf distance obtained from MRI images. RESULTS: RTPL was slightly longer [11 mm (12), P < 0.001] at the right side. The 80%-rule overestimated RTPLs with 0.5% at the right and 2.7% at the left side. Straight MRI distance tended (P = 0.09) to perform slightly better than tape measure distance. CONCLUSION: The travelled cf path is slightly longer at the right than at the left body side and the straight MRI distance tends to perform better than tape measure distance. The present study supports the advice of the expert consensus group to measure cf-PWV at the right body side using a sliding caliper when tape measure distance cannot be obtained in a straight line.

Control of ecdysteroidogenesis in prothoracic glands of insects: a review.

The very first step in the study of the endocrine control of insect molting was taken in 1922. Stefan Kopec characterized a factor in the brain of the gypsy moth, Lymantria dispar which appeared to be essential for metamorphosis. This factor was later identified as the neuropeptide prothoracicotropic hormone (PTTH), the first discovery of a series of factors involved in the regulation of ecdysteroid biosynthesis in insects. It is now accepted that PTTH is the most important regulator of prothoracic gland (PG) ecdysteroidogenesis. The periodic increases in ecdysteroid titer necessary for insect development can basically be explained by the episodic activation of the PGs by PTTH. However, since the characterization of the prothoracicostatic hormone (PTSH), it has become clear that in addition to 'tropic factors', also 'static factors', which are responsible for the 'fine-tuning' of the hemolymph ecdysteroid titer, are at play. Many of these regulatory factors are peptides originating from the brain, but also other, extracerebral factors both of peptidic and non-peptidic nature are able to affect PG ecdysteroidogenesis, such as the 'classic' insect hormones, juvenile hormone (JH) and the molting hormone (20E) itself. The complex secretory pattern of ecdysteroids as observed in vivo is the result of the delicate balance and interplay between these ecdysiotropic and ecdysiostatic factors.

Insulin-like peptides in Spodoptera littoralis (Lepidoptera): Detection, localization and identification.

Insulin is an extensively studied peptide hormone in mammals. However, insulin is not restricted to vertebrates, but has also been identified in invertebrates, among whom several insect species. These insulin-like peptides (ILPs) show structural and-at least some-functional homology with mammalian insulin and act through a conserved pathway. Yet many aspects of insulin function in insects remain to be unveiled. We analyzed the presence of ILPs in the cotton leafworm, Spodoptera littoralis, at two levels: (1) cellular localization of ILPs in whole tissues of the central nervous system from S. littoralis, and (2) detection and identification of ILPs at nucleotide level. To our knowledge, nothing about the presence of ILPs in S. littoralis has been described so far. By whole mount in situ immunolocalization, we localized bombyxin-like material in S. littoralis in four pairs of pars intercerebralis cells and in the corpus cardiacum-corpus allatum complexes. In addition, we have cloned two different S. littoralis ILP precursor cDNAs by a combination of PCR and RAcE. The corresponding precursor polypeptides ('Sl-ILPP1' and 'Sl-ILPP2') show significant sequence homology with precursors for bombyxin and other bombyxin-related peptides. Our results strongly suggest that the S. littoralis ILPs belong to the category of bombyxin-analogs.