Daughters caregiving for hispanic and non-hispanic alzheimer patients: Does ethnicity make a difference?

This study assessed Cuban-American Hispanic and White non-Hispanic daughters who were major caregivers for their mothers suffering from Alzheimer's Disease. Although patients in both ethnic groups did not differ in their level of cognitive and functional impairment, Cuban-American Hispanic patients were significantly more likely to be living in their daughters' homes while the White non-Hispanic patients resided in institutional settings. Caregivers were equivalent in their knowledge and utilization of community services, but Cuban-American daughters were significantly more aware of financial aid resources. Cuban-American patients were significantly more depressed than their White non-Hispanic counterparts with daughters showing similar but nonsignificant trends. The impact of cultural factors on caregiving is discussed.     

Evidence for a glycosaminoglycan on the nudel protein important for dorsoventral patterning of the drosophila embryo.

Dorsoventral patterning of the Drosophila embryo requires Nudel, a large mosaic protein with a protease domain. Previous studies have implicated Nudel's protease domain as the trigger of a proteolytic cascade that activates the Toll signaling pathway to establish dorsoventral polarity in the embryo. However, the function of other regions of Nudel has been unclear. By using two-dimensional gel electrophoresis and site-directed mutagenesis, we have obtained evidence that the N-terminal region of Nudel contains a site for glycosaminoglycan (GAG) attachment that is required for dorsoventral patterning. Disruption of this site blocks a disulfide-based association between N- and C-terminal Nudel polypeptides and proteolytic activation of Nudel's protease domain. We discuss how a GAG chain on Nudel might be required for Nudel protease activation.     

The Effect of Intensive Insulin Therapy on the Insulin-regulatable Glucose Transporter (GLUT4) Expression in Skeletal Muscle in Type 1 Diabetes

Studies in normal man and rodents have demonstrated that the expression of the dominant glucose transporter in skeletal muscle, GLUT4, is regulated by insulin at supraphysiological circulating levels. The present study was designed to determine whether intensified insulin replacement therapy for 24 h given to patients with Type 1 diabetes in poor metabolic control was associated with an adaptive regulation of GLUT4 mRNA and protein levels in vastus lateralis muscle. Nine Type 1 diabetic patients with a mean HbA_1c of 10.3% were included in the protocol. After intensified treatment with soluble insulin for 24 h the fasting plasma glucose concentration decreased from 20.8 ± 2.3 (SD) to 8.7 ± 2.3 mmol 1^?1 whereas the fasting serum insulin level increased from 0.06 ± 0.02 to 0.17 ± 0.09 nmol 1^?1 However, despite a 2.8-fold increase in serum insulin levels and more than a halving of the plasma glucose concentration for at least 15 h no significant alterations occurred in the amount of GLUT4 protein (0.138 ± 0.056, poor control vs 0.113 ± 0.026 arb. units, improved control, p = 0.16) or GLUT4 mRNA (96432 ± 44985, poor control vs 81395 ± 25461 arb. units, improved control, p = 0.54). These results suggest, that in spite of evidence that high insulin levels affect GLUT4 expression in muscle, changes in serum insulin within the physiological range do not play a major role in the short-term regulation of GLUT4 expression in Type 1 diabetic patients.     

A rat model of reproducible cerebral infarction using thrombotic blood clot emboli.

The purpose of this study was the development of a model of embolic stroke with high reproducibility concerning infarct volume. In 37 male Sprague-Dawley rats, the internal carotid artery was embolized with in vitro preformed suspensions of autologous microemboli resembling arterial thrombi. With a method of continuous flow through the carotid arterial catheter, reflux of blood with uncontrolled clotting and embolization was avoided, thereby providing control animals free of ischemic damage. The embolized animals had arterial occlusions on angiograms immediately after embolization and no spontaneous recanalization on angiograms 2 h later. The cerebral blood flow measured by the intra-arterial 133Xe injection method decreased to 21-37% of baseline values. All embolized animals developed hemiparesis with spontaneous circling behavior, embolization with more than 150 microliters clot suspension resulted in hemispherical infarcts. There was a strong statistically significant correlation between amount of emboli, rate of vascular occlusion, and volume of infarcted tissue. This is the first model presented utilizing autologous in vitro microemboli imitating "white" arterial thrombi. The animals developed infarction, resembling human stroke.     

Quantitative thallium-201 scintigraphy after dipyridamole infusion combined with low level exercise in healthy volunteers

To establish test specific normal limits for quantitative analysis of uptake and washout of ²⁰¹Tl after dipyridamole infusion combined with low level exercise, 20 healthy volunteers were studied with low likelihood of coronary artery disease (CAD) assessed by a stepwise probability analysis based on age, sex, symptoms, resting electrocardiogram, and exercise electrocardiography. Likelihood of CAD in these volunteers was calculated as 1%. After dipyridamole infusion combined with low level exercise, one volunteer complained of headache; no other side effects were observed. There were no chest pain complaints. Maximal hemodynamic changes were achieved during the 6th and 7th min of the test. No ST segment depression was recorded. Visual analysis of the ²⁰¹Tl scintigrams was normal in all volunteers. Mean regional washout at 4 h was 44.37%±2.11%. The regional washout in the 70° LAO view (46.65%±1.10%) was significantly higher than in the anterior and 30° LAO views (43.44%±1.50% and 43.02%±1.45%, respectively). Profiles of uptake and washout of ²⁰¹Tl were different after dipyridamole infusion combined with low level exercise as compared to maximal exercise. Thus, in quantitative analysis of ²⁰¹Tl scintigraphy after dipyridamole infusion in conjunction with low level exercise as applied in the present study, it is mandatory to use normal limits of uptake and washout of ²⁰¹Tl derived from healthy volunteers who underwent the same combined protocol.     

Increased NADPH-diaphorase activity in canine myxomatous mitral valve leaflets

Comparable pathological changes in the mitral valve have been described in dogs, pigs and human patients with myxomatous mitral valve disease (MMVD), i.e., primary mitral valve prolapse. The progressive myxomatous changes are probably a response to repeated impact on the leaflets, and endothelial stress or damage probably plays a central role in the pathogenesis. Little, however, is known about the vasoactive substances that mediate the subendothelial changes. The aim of this study was to investigate the expression of nitric oxide synthase (NOS) in canine mitral valve leaflets and to relate the findings to MMVD changes. The mitral valve was taken post mortem from 12 dogs (six males and six females) and a whole valve NADPH (the reduced form of nicotinamide-adenine dinucleotide phosphate) diaphorase (NADPH-d) reaction was performed. Macroscopical (semiquantitative) and microscopical (computer image analysis) evaluations of the staining due to NADPH-d activity were performed at four specific areas of the valve and related to microscopical signs of MMVD and gross signs of thickening or prolapse, or both. Macroscopically, the NADPH-d colour grade was correlated with the degree of MMVD (P=0.01). In addition, endothelial NADPH-d staining intensity was correlated with macroscopical signs of disease (P=0.004) as well as with collagen degeneration (P=0.008) and deposition of mucopolysaccharides (P=0.02). Age, gender and specific area of the valve did not seem to influence the NADPH-d activity. In conclusion, increased NADPH-d activity, suggesting increased NOS expression, was found in areas of the mitral valve with myxomatous changes. This indicates that nitric oxide (NO) may play a role in the pathogenesis of MMVD in dogs.     

Einige Befunde zur Sinnesphysiologie der Kaltblüterzecke Amblyomma testudinis

Zusammenfassung Aus eigener Zucht stammende Larven, Nymphen und Imagines von Amblyomma testudinis wurden auf ihre Sinnesleistungen hinsichtlich Phototaxis, Thermotaxis, Geotaxis und Chemotaxis untersucht. Es ergab sich ein entwicklungsabhängiger Wandel im phototaktischen Verhalten von anfangs positiver Phototaxis bei den Larven über indifferente Phototaxis bei vollgesogenen Larven und nüchternen Nymphen zu negativer Phototaxis bei vollgesogenen Nympen sowie - und -Imagines. Sämtliche Entwicklungsstadien mit Ausnahme der -Imagines verhalten sich temperaturindifferent vor dem Kontakt mit einem Wirt; vollgesogene Larven und Nymphen dagegen bevorzugen niedrige Temperaturen. Nymphen und Imagines, die noch nicht gesogen haben, reagieren negativ geotaktisch. Sie erklettern vermutlich in der Natur die Spitzen von Pflanzen und Steinen, um dort das Vorbeikriechen eines Wirtes abzuwarten. Imagines von Amblyomma testudinis reagieren mit einer positiven Chemotaxis auf Schlangen stärker als auf Kröten. Auch Substrat aus Schlangenbehältern enthält mindestens für 30 Std nach der Entfernung der Schlangen chemotaktisch wirksame Stoffe.

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Contributions to sensory physiology of the tick Amblyomma testudinis

Summary Phototaxis, thermotaxis, geotaxis and chemotaxis of larvae, nymphs and adults of Amblyomma testudinis from own breedings were studied. The phototactic behaviour changed according to the different stages of development: unfed larvae were positively phototactic, fed larvae and unfed nymphs were indifferent, fed nymphs but also the adults showed a negative phototaxis.—All stages of development besides the females reacted without any preference for a distinct temperature, whereas larvae and nymphs after feeding prefered lower temperatures.—Unfed nymphs and adults were negatively geotactic which corresponds to their natural behaviour of climbing plants for catching hosts.—Adults of Amblyomma testudinis showed a higher rate of chemotaxis for snakes than for toads; substrate from snake cages containes chemotaxis inducing substances for more than 30 hours after elimination of the snakes.