Feeding patterns of Triatoma longipennis Usinger (Hemiptera, Reduviidae) in peridomestic habitats of a rural community in Jalisco State, Mexico

We analyzed triatomine blood feeding patterns to evaluate the role of peridomiciles in Trypanosoma cruzi transmission at the rural village of Tepehuaje de Morelos at Jalisco State, Mexico (1999). A total of 206 bugs were collected in 11 out of 26 households (42.3%). Nymphs predominated in the collections (64.9% of the total). Except for one Triatoma barberi female, a species that belongs to the protracta species complex, all adults were Triatoma longipennis, a species of the phyllosoma complex. Triatomines were exclusively present in peridomestic sites mainly piles of tiles and bricks, and none were found indoors. Overall infection rate was 56.6% and no significant differences (P > 0.05) were observed between nymphs and adults or males and females. Identified blood meals were chicken (29.4%), opossum (20.9%), pig (24.5%), murid (20.9%), dog (3.5%), and armadillo (0.7%). No gut content reacted against anti-human, anti-bovine, anti-rabbit, and anti-cat sera. In contrast to fifth nymphs and adults, 87% of the small nymphs fed on one host, indicating that they are less mobile than other stages. Most fifth nymphs and adults fed on domestic hosts, while small nymphs mainly fed on opossum and murid. Infection blood-meal indexes were around 50% for single meals on opossum and murid, stressing their importance as trypanosome donors. Peridomiciles in Tepehuaje could be regarded as interaction sites among domestic and wild and synanthropic mammals and triatomines, which would facilitate circulation of the same T. cruzi strains between domestic and sylvatic cycles. Stone-made walls and building materials, which hold synanthropic rodents and opossums, should be considered as targets for vector control measures.     

Colonization of rock pile boundary walls in fields by sylvatic triatomines (Hemiptera: Reduviidae) in Jalisco State, Mexico

Granite rocks is a very abundant material in Mexico because they are used habitually as borders for fields. The current work established the significance of this ecotype as a colonization site for triatomines of the Phyllosoma complex. Seven sites, arbitrary selected, in San Martin de Hidalgo municipality (Mexico) were investigated in April 2002 by using 210 mouse bait-traps left during the night in wall hollows. One hundred and seventy-two triatomines of all life stages were collected from the seven sites. Triatomines adhered to the tape that covered the traps or were found near them, and 36.6% of the traps collected triatomines. The principal species was Triatomia longipennis Usinger (1939) and low numbers of Triatoma picturata Usinger (1939) were found. The nymphal population was very young, probably corresponding to the reproductive period in April (end of the dry season). The infection rate of the triatomines for Trypanosoma cruzi was 49%. Because collecting triatomines in the field is laborious and time-consuming, the mouse bait-trap method found to be practical to assess the population of triatomines within a sylvatic habitat.     

Characteristics associated with use or intention to use indoor tanning among adolescents

BACKGROUND: Indoor tanning is a popular behavior that may increase skin cancer risk. OBJECTIVE: To examine characteristics associated with use or intention to use indoor tanning among adolescents. METHODS: A telephone interview was conducted with 1273 adolescents, aged 14 to 17 years, in the Minneapolis-St Paul, Minn, and Boston, Mass, metropolitan areas. Questions included demographic and phenotypic characteristics, knowledge, attitudes, social factors, use of indoor tanning, and intention to tan indoors. RESULTS: Twelve percent of boys and 42% of girls had tanned indoors. Among nontanners, 22.4% planned to start, and 77.2% of tanners planned to continue tanning indoors. Nontanners and tanners at risk for future indoor tanning use were each significantly more likely to be female, less likely to use sun protection, less knowledgeable about skin cancer risks, more likely to agree that tans were attractive, and more strongly influenced by social factors compared with their low-risk counterparts. CONCLUSIONS: Our data suggest that intention to tan indoors may identify a group of adolescents at risk for adopting the behavior; prospective studies are needed for confirmation.     

Postural stability in the elderly: empirical confirmation of a theoretical model

The study investigated whether physiological factors related to specific body systems can explain postural control as measured by the scalar distance at a given time between the center of pressure (COP) and the center of mass (COM), the COP-COM variable. The data from 46 healthy subjects and 29 subjects with disabilities due to stroke or diabetic peripheral neuropathy were analyzed. The biomechanical variable COP-COM was determined using two force platforms and an optoelectric system. Three systems were considered as possible predictors of the COP-COM amplitude: sensory (somatosensory and vision), musculoskeletal and central processor. A confirmatory analysis was done using structural equation modeling. Strength explained 23.74% of the COP-COM amplitude in the antero-posterior (A/P) with eyes open (EO) condition, and in the medio-lateral (M/L) direction strength explained 40.73 and 28.75% in the EO and eyes closed (EC) respectively. In the A/P direction with EC, 51.75% of the COP-COM amplitude variance was explained mainly by the somatosensory system. This study highlight the role of peripheral somatosensory input and muscle strength in the maintenance of postural stability during quiet stance in the elderly. The indirect action of the different systems on the COP-COM amplitude supports the systems theory.     

CT and MR imaging of nitinol stents with radiopaque distal markers

PURPOSE: To evaluate imaging characteristics and artifacts of a nitinol stent with distal tantalum markers with computed tomography (CT) angiography and magnetic resonance (MR) angiography. MATERIALS AND METHODS: A vascular phantom was built to simulate in-stent restenosis. A nitinol stent with tantalum markers (Luminexx stent) was evaluated with CT angiography in different orientations relative to the z-axis and with MR angiography in different positions relative to both B0 and the readout gradient. Stenosis measurements were compared with conventional digital subtraction angiography for both modalities. In-stent signal intensity obtained with different flip angles was assessed in two nitinol stents with distal markers (Luminexx stent and SMART stent) and one without markers (Memotherm-FLEXX stent). RESULTS: Stenosis detection was not possible with CT angiography when the stent was perpendicular to the z-axis because of streak-like artifacts induced by tantalum markers. Stenosis evaluation with multiplanar reformation was accurate when the stent was in parallel and oblique orientations relative to the table axis. With MR angiography, metallic artifacts were mostly related to the stent orientation with B0, whereas orientation of the readout gradient had little influence. The mean error (overestimation) for stenosis measurements varied between 0.1% and 7.4% for CT imaging in parallel and oblique positions and 3.6% and 9.5% for MR imaging. Higher flip angles did not improve signal intensity inside the three stents tested. CONCLUSION: CT and MR angiography can be used for evaluating the patency of stents with distal markers that are parallel or oblique relative to the table axis (iliac, carotid, or femoral stents). MR angiography is preferred if the stent is perpendicular to the table axis (renal stent).     

Long-term protection of obese Zucker rat kidneys from fibrosis and renal failure with an angiotensin-converting enzyme inhibitor/diuretic combination

Some combinations of antihypertensive agents were shown to reduce proteinuria in patients with renal failure. However, preventive effects of such combinations on renal structure and function are presently unknown when treatment is administered before the onset of renal abnormalities. We thus investigated the long-term effects of an angiotensin-converting enzyme (ACE) inhibitor (perindopril)/diuretic (indapamide) combination (per/ind) in the Zucker rat, a classical model of chronic renal failure associated with obesity, hyperlipidemia, and insulin resistance. Two-month-old lean and obese Zucker rats, presenting normal renal structure and function at this young age, received per/ind (0.76 + 0.24 mg/kg of body weight/day) or the vehicle of this combination by daily gavage. After 8.5 consecutive months of treatment, those 10.5-month-old rats were used for determination of renal structural and functional parameters which were examined using standard renal clearance experiments and kidney tissue analysis. Per/ind prevented focal and segmental glomerular hyalinosis and tubulo-interstitial damage in obese rats. Treatment was also associated with a significant reduction in several staining markers of glomerular and interstitial fibrosis. The hypertrophy of superficial glomeruli and the mesangial expansion of deep glomeruli observed in control rats were reduced in per/ind-treated obese rats. The severe proteinuria observed in 10.5-month-old control obese rats was prevented by per/ind, while glomerular filtration and renal hemodynamic parameters reached similar values to those obtained in lean animals. These results show that long-term treatment with this ACE inhibitor/diuretic combination protects renal structure and function in the obese Zucker rat, emphasizing the potential efficiency of such therapy in renal failure prevention.     

Lipid atherogenic risk markers can be more favourably influenced by the cis-9,trans-11-octadecadienoate isomer than a conjugated linoleic acid mixture or fish oil in hamsters

The aim of our present study was to compare the efficiency of conjugated linoleic acids (CLA) and fish oil in modulating atherogenic risk markers. Adult male hamsters were given a cholesterol-rich diet (0.6 g/kg) for 8 weeks; the diet was supplemented with 5 g cis-9,trans-11-CLA isomer/kg, 12 g CLA mixture (CLA-mix)/kg, 12 g fish oil/kg or 12 g fish oil+12 g CLA-mix/kg. The plasma cholesterol status was improved only with the cis-9,trans-11-CLA (HDL-cholesterol and HDL-cholesterol:LDL-cholesterol ratio, P<0.05), but was of borderline significance for CLA-mix (HDL-cholesterol:LDL-cholesterol ratio, P=0.06), with an increase (33-40 %) in the liver lipoprotein receptors (scavenger receptor-type I and LDL ApoB/E receptor) and HDL-binding protein 2 (P<0.05). A 100 % pigment gallstones incidence and a slight insulin resistance (homeostatic model assessment index) were observed in the CLA-mix-fed hamsters (P=-0.031). In comparison, fish-oil feeding alone improved merely the scavenger receptor-type I and HDL-binding protein 2 liver status and faeces sterol output. For most of our present observations, the concomitant intake of fish oil and CLA-mix gave dominant effects that were exclusive and specific to one or the other oil. In conclusion, part of the beneficial effects of CLA in the present study can be ascribed to the cis-9,trans-11-isomer, and these did not generally overlap with those of fish oil. In addition, the CLA-mix effects are clearly affected by the marine (n-3) fatty acids.