Measurements in the peripheral retina using LDF and laser interferometry are mainly influenced by the choroidal circulation

PURPOSE: Two laser based methods for the assessment of ocular hemodynamics in humans have been investigated: laser Doppler flowmetry (LDF) and laser interferometric measurement of fundus pulsation amplitude (FPA). When the laser with either of the two methods is focused onto the fovea it is obvious that only choroidal blood flow contributes to the signals. When the laser is, however, directed to other parts of the retina the situation is more complex. Whereas the retina shows a pronounced vasoconstrictor response to systemic hyperoxia the effect in the choroid is small. We therefore investigated the effect of 100% O2 breathing on results as obtained with the above mentioned techniques at different fundus locations. METHODS: Twelve healthy subjects were included. Four 15-minutes 100% O2 breathing periods were scheduled for each subject. During two of these breathing periods LDF was performed at the fovea (ChBFf) and at a fundus location approximately 7.5 degrees nasally to the fovea (ChBFp), respectively. During the other two periods FPA was assessed at the same fundus locations (FPAf, FPAp). RESULTS: ChBFf tended to decrease during 100% oxygen breathing (6 +/- 4%), but this effect was not significant. The decrease in ChBFp (10 +/- 4%), was comparable. FPAf (10 +/- 2%; P < 0.001) and FPAp (13 +/- 2%; P < 0.001) decreased significantly during systemic hyperoxia, but again there was no difference in the response obtained at the two fundus locations. CONCLUSION: When LDF and FPA are applied at the peripheral retina the obtained signal is mainly influenced by the choroidal circulation.     

Effects of pentylenetetrazol-induced kindling of seizures on rat emotional behavior and brain monoaminergic systems

The influence of pentylenetetrazol (PTZ)-induced kindling of seizures on the rat emotional behavior, the brain monoamine turnover rate measured in vitro, and correlation between behavioral and biochemical parameters, were examined in rats. The repeated administration of PTZ (35 mg/kg, ip) evoked kindled seizures in rats (Stage 4 or 5 of clonic-tonic convulsions-maximum). PTZ kindling caused selective changes in the rat emotional behavior, present in some models of anxiety only (a decreased freezing time in the conditioned freezing test and a decreased spontaneous and aversively conditioned ultrasonic vocalization). Simultaneously, PTZ kindling decreased the concentration of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the prefrontal cortex, decreased the DA (HVA/DA ratio) turnover rate in the striatum, and inhibited the serotonin (5-HT) metabolism (5-HIAA/5-HT ratio) in the hippocampus and the prefrontal cortex. Correlations between dopamine (DA) or 5-HT regional metabolic rates in brain structures and animal behavior were either abolished or reversed in PTZ-kindled animals. It is concluded that both DA and 5-HT systems contribute to the emotional effects of PTZ-induced kindling of seizures. The hypothesis is put forward that PTZ kindling-induced inhibition of the serotonergic innervation may lead to the compensatory increase in 5-HT(1A) receptors in the dentate gyrus of the hippocampus, thus evoking the anxiolytic-like changes in animal behavior.     

Rapid desensitization of receptors for pituitary adenylate cyclase-activating polypeptide (PACAP) in chick cerebral cortex

Pituitary adenylate cyclase-activating polypeptide (PACAP38) potently stimulates cyclic AMP formation in slices of chick cerebral cortex. One- to fifteen-minute pretreatment of slices with 30 nM PACAP38 led to a time-dependent attenuation (when compared with values observed in the control tissue) of the cyclic AMP response produced by subsequent re-stimulation with 1 microM PACAP38. Concentration-response curve for restimulation with PACAP38 applied at 0.01-1 microM to tissue slices preincubated for 15 min with 30 nM PACAP38 revealed dose-dependent decreases in subsequent cyclic AMP responses by 16-37%. It is concluded that in chick cerebral cortex, the receptors mediating PACAP-driven cyclic AMP responses (PAC1 receptors) undergo rapid homologous desensitization.     

The importance of intraoperative angiographic findings for predicting long-term patency in coronary artery bypass operations

BACKGROUND: The quality of anastomosis is the cornerstone in coronary artery bypass operations. Intraoperative coronary angiography confirms graft patency with the possibility to revise graft failure. The aim of this study was to describe the lesions found at "on-table" angiography, and to evaluate the significance of these immediate angiographic findings for the long-term patency. METHODS: A total of 57 grafts (42 left internal mammary artery grafts and 15 saphenous vein grafts) in 45 patients who underwent off-pump coronary artery bypass operations were included. On-table angiography was carried out with fixed angiographic equipment installed in the operating room. Follow-up angiographies were performed at 3 months and at 12 months. RESULTS: The most frequent finding in an on-table angiogram was spasm, which was not present at follow-up. Out of nine kinks, only one developed into a significant stenosis at follow-up. Of 44 grafts that were normal on-table, 37 (84%) were normal at the follow-up. Of 11 grafts with significant lesions on-table, eight (73%) were normal at the follow-up. Five percent of the grafts were revised because of the on-table angiography. CONCLUSIONS: On-table angiograms can be occasionally difficult to interpret because not all findings are important for later patency. Optimal results on-table predict good long-term results with a negative predictive value of 0.84, whereas significant lesions on-table have less impact on the follow-up results because the positive predictive value was only 0.38.     

An ELISA procedure for human Lp(a) quantitation using monoclonal antibodies

The present study describes a monoclonal antibody-based enzyme immunoassay (ELISA) for the quantitation of lipoprotein(a), Lp(a), in human plasma. Two antibodies to Lp(a), 2F4E7 and 8G12G7, were produced and characterized as specific and high affinity antibodies against Lp(a). A reference control serum was utilized to prepare the standard curve in a Lp(a) concentration range from 0.015 to 0.5 ug/ml. A biotinylated monoclonal antibody against apoB-LDL was used as the second antibody. The comparison of the standardized ELISA using mAb 2F4E7 with an ELISA using a characterized mAb against Lp(a) (clone KO9) as capture antibody showed that the Lp(a) concentration of two standard sera was similar with both assays. Furthermore, when compared with an electroimmunoassay kit, similar Lp(a) concentrations for the standard were also obtained.     

Dietitians and exercise professionals in a childhood obesity treatment team

There has been a remarkable increase in the prevalence of childhood obesity in most countries in recent years, which indicates that modern lifestyle is the triggering factor for genetic susceptibility. This report focuses on the two main environmental factors, nutrition and physical activity, that could influence paediatric obesity development, and how health professionals can address these aspects in the management of childhood obesity in a multidisciplinary treatment team. First, the role of a nutrition expert in the multidisciplinary obesity team is discussed and then the importance of physical activity in the treatment of paediatric obesity. The part on nutrition highlights some interesting areas in this field, namely glycaemic index, high-protein diet, fast foods, portion sizes and soft-drink consumption. Dietary treatment in childhood obesity should be combined with changes in physical activity to promote long-term weight loss. Research on the physical activity of children and adolescents indicates some significant changes over the last decades, which are also reviewed. Factors such as sports club participation and television viewing are discussed. The appropriate physical activity level and effective physical activity programmes are also presented. Physical activity can be promoted in childhood obesity treatment in many ways. Practical advice regarding physical activity programme and the role of exercise professionals in childhood obesity treatment team is given. Conclusion: For successful obesity management, the child should be assessed and treated by a multidisciplinary team, including a physician, dietitian, exercise expert, nurse and behavioural therapist.     

Neuronal and astroglial alterations in the hippocampus of a mouse model for type 1 diabetes

The influence of diabetes mellitus on brain pathology is increasingly recognized. Previous contributions of our laboratory demonstrated in models of type 1 diabetes (nonobese diabetic and streptozotocin (STZ)-treated mice), a marked astrogliosis and neurogenesis deficit in hippocampus and increased expression of hypothalamic neuropeptides. In the present investigation, we further analyzed alterations of astroglia and neurons in the hippocampus of mice 1 month after STZ-induced diabetes. Results showed that these STZ-diabetic mice presented: (a) increased number of astrocytes positive for apolipoprotein-E (Apo-E), a marker of ongoing neuronal dysfunction; (b) abnormal expression of early gene products associated with neuronal activation, including a high number of Jun + neurons in CA1 and CA3 layers and dentate gyrus, and of Fos-expressing neurons in CA3 layer; (c) augmented activity of NADPH-diaphorase, linked to oxidative stress, in CA3 region. These data support the concept that uncontrolled diabetes leads to hippocampal pathology, which adjoin to changes in other brain structures such as hypothalamus and cerebral cortex.     

Mineralocorticoid treatment upregulates the hypothalamic vasopressinergic system of spontaneously hypertensive rats

Mineralocorticoid effects in the brain include the control of cardiovascular functions, induction of salt appetite, interaction with the vasoactive neuropeptides arginine vasopressin (AVP) and angiotensin II and development or aggravation of hypertension. In this regard, mineralocorticoids may play a pathogenic role in rats with a genetic form of hypertension (spontaneously hypertensive rats, SHR). Our objective was to compare the response of the hypothalamic vasopressinergic system to mineralocorticoid administration in SHR and control Wistar-Kyoto (WKY) rats. Sixteen-week-old male SHR showing a systolic blood pressure of 190 +/- 5 mm Hg and normotensive WKY rats (130 +/- 5 mm Hg) were treated subcutaneously with oil vehicle or a single 10-mg dose of deoxycorticosterone acetate (DOCA). After 2 h, rats were sacrificed and brains prepared for immunocytochemistry of Fos and vasopressin V1a receptor (V1aR) and for non-isotopic in situ hybridization of AVP mRNA. In the basal state, SHR demonstrated a higher number of AVP mRNA- and V1aR-immunopositive cells in the magnocellular division of the paraventricular hypothalamic nucleus (PVN) than WKY rats. After DOCA injection, SHR responded with a significant increase in both parameters with respect to vehicle-injected SHR. In WKY rats, DOCA was without effect on AVP mRNA although it increased the number of V1aR-positive cells. Changes in the number of Fos-positive nuclei were measured in the PVN, median preoptic nucleus (MnPO) and organum vasculosum of the lamina terminalis (OVLT), a circumventricular region showing anatomical connections with the PVN. In vehicle-injected rats, the PVN of SHR showed a higher number of Fos-positive nuclei than in WKY rats, whereas after DOCA treatment, a significant increment occurred in the OVLT but not in the PVN or MnPO of the SHR group only. These data suggest that the enhanced response of the vasopressinergic system to mineralocorticoids may contribute to the abnormal blood pressure of SHR.     

Surgical Workload and Cost of Postoperative Adhesion-related Intestinal Obstruction: Importance of Previous Surgery

Postoperative intraabdominal adhesions cause morbidity of varying degree. Intestinal obstruction is the most severe complication of adhesions. This study examined the importance of previous surgery on clinical and economic workloads caused by intestinal obstruction due to postoperative intraabdominal adhesions. All emergency hospitalizations due to adhesion-related intestinal obstruction from January 1, 1999 to December 31, 1999 in a hospital district serving roughly 450,000 inhabitants was reviewed retrospectively. The patient population was divided into six groups according to the site of previous surgery, and the total as well as group-related surgical workload and direct costs of inpatient care were analyzed. There were 123 hospitalizations due to postoperative adhesion-related intestinal obstruction during the study period. A total of 101 patients had experienced 176 operations. The most prevalent operations were colorectal (with or without other operations), upper abdominal, and female reproductive system procedures. Colorectal surgery preceded 40% and 38% of inpatient episodes and inpatient days, respectively. Altogether, 40 operations were performed because of adhesion-related intestinal obstruction. No differences between groups were seen in terms of the mean operating or theater time. Total annual inpatient costs due to emergency hospitalizations for intestinal adhesion-related obstruction related to colorectal surgery in a hospital district serving roughly 450,000 inhabitants was $72,520.60 (U.S. dollars) which accounted for 35.3% of all annual costs caused by postoperative adhesion-related intestinal obstructions. There were no significant differences between groups regarding the total mean inpatient episode costs. Intestinal obstruction due to postoperative adhesions poses substantial costs for the society. Colorectal operations are the most important procedures preceding adhesion-related intestinal obstruction, accounting for 35.3% to 46.8% of the total clinical workload or costs attributable to postoperative adhesion-related obstruction.