American Society of Neuroradiology research survey 2001

RATIONALE AND OBJECTIVES: Research is a critical component of the mission of academic radiology, and success in research is necessary for the future of neuroradiology. Thus, the authors set out to establish a baseline of research activities of American Society of Neuroradiology (ASNR) members. MATERIALS AND METHODS: The authors surveyed 100 fellowship program directors. The survey was Web based, with recruitment from the ASNR Fellowship Database survey site and with e-mail and fax solicitations to the Web site. Questions focused on neuroradiologist and neuroradiology fellow involvement in research. RESULTS: Forty-eight of the 100 program directors (48%) responded. Several key findings emerged: (a) About one-third of fellowship programs require all fellows to do some research, with most fellows receiving less than 1 day per week of academic time; (b) just over half of the programs expect fellows to publish a paper; (c) about two-thirds of academic neuroradiologists get at least 1 academic day per week; (d) most academic neuroradiologists perform research, but most of this research is unfunded; and (e) about nine of 10 academic sections have at least one neuroradiologist with some extramural funding. CONCLUSION: The relative lack of extramural funding among academic neuroradiologists is a reality that is probably multifactorial; however, there may be a direct relationship between amount of academic time free from clinical duties and successful competition for funding. The time (and, thus, financial) support of research-oriented fellows and faculty should be increased.     

The contribution of inner and outer retinal photoreceptors to infra‐slow oscillations in the rat olivary pretectal nucleus

A subpopulation of olivary pretectal nucleus (OPN) neurons discharges action potentials in an oscillatory manner, with a period of approximately two minutes. This ‘infra‐slow’ oscillatory activity depends on synaptic excitation originating in the retina. Signals from rod‐cone photoreceptors reach the OPN via the axons of either classic retinal ganglion cells or intrinsically photosensitive retinal ganglion cells (ipRGCs), which use melanopsin for photon capturing. Although both cell types convey light information, their physiological functions differ considerably. The aim of the present study was to disentangle how rod‐cone and melanopsin photoresponses contribute to generation of oscillatory activity. Pharmacological manipulations of specific phototransduction cascades were used whilst recording extracellular single‐unit activity in the OPN of anaesthetized rats. The results show that under photopic conditions (bright light), ipRGCs play a major role in driving infra‐slow oscillations, as blocking melanopsin phototransmission abolishes or transiently disturbs oscillatory firing of the OPN neurons. On the other hand, blocking rod‐cone phototransmission does not change firing patterns in photopic conditions. However, under mesopic conditions (moderate light), when melanopsin phototransmission is absent, blocking rod‐cone signalling causes disturbances or even the disappearance of oscillations implying that classic photoreceptors are of greater importance under moderate light. Evidence is provided that all photoreceptors are required for the generation of oscillations in the OPN, although their roles in driving the rhythm are determined by the lighting conditions, consistent with their relative sensitivities. The results further suggest that maintained retinal activity is crucial to observe infra‐slow oscillatory activity in the OPN.     

Adult patients with sporadic polycystic kidney disease: the importance of screening for mutations in the PKD1 and PKD2 genes

Background

ADPKD is one of the most common inherited disorders, with high risk for end-stage renal disease. Numerous patients, however, have no relatives in whom this disorder is known and are unsure whether they may transmit the disease to their offsprings. The aim of this study was to evaluate whether germline mutation analysis adds substantial information to clinical symptoms for diagnosis of ADPKD in these patients.

Methods

Clinical data included renal function and presence of liver or pancreas cysts, heart valve insufficiency, intracranial aneurysms, colonic diverticles, and abdominal hernias. Family history was evaluated regarding ADPKD. Germline mutation screening of the PKD1 and PKD2 genes was performed for intragenic mutations and for large deletions.

Results

A total of 324 adult patients with ADPKD including 30 patients without a family history of ADPKD (sporadic cases) were included. PKD1 mutations were found in 24/30 and PKD2 mutations in 6 patients. Liver cysts were present in 14 patients and intracranial aneurysms in 2 patients. Fourteen patients (45%) had no extrarenal involvement. Compared to the 294 patients with familial ADPKD, the clinical characteristics and the age at the start of dialysis were similar in those with sporadic ADPKD.

Conclusion

The clinical characteristics of patients with sporadic and familial ADPKD are similar, but sporadic ADPKD is often overlooked because of the absence of a family history. Molecular genetic screening for germline mutations in both PKD1 and PKD2 genes is essential for the definitive diagnosis of ADPKD.     

Randomized trial and local biological effect of autologous platelets used as adjuvant therapy for chronic venous leg ulcers

OBJECTIVES: Platelet products have been proposed as adjuvant therapy for wound healing. We undertook this study to determine the healing effect of topically applied frozen autologous platelets (FAP) on chronic venous ulcers, compared with effect of placebo, and whether use of topical FAP modifies local expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), interleukin 8 (IL-8), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in wound fluid. METHODS: This randomized, placebo-controlled, double-blind trial was carried out in institutional practice, with ambulatory patients with proved chronic venous leg ulcers. In all patients, whole venous blood was drawn for preparation of FAP. FAP or normal saline solution was applied three times per week for up to 12 weeks, together with hydrocolloids and standardized compression bandages. Leg ulcer surface was assessed with numerical pictures. IL-8, VEGF, KGF, and TIMP-1 levels were determined (enzyme-linked immunosorbent assay) in wound fluid after each 4 weeks of treatment. RESULTS: Fifteen patients were randomized into two groups with comparable leg ulcer characteristics. Mean percent reduction in ulcer area was 26.2% in the FAP group versus 15.2% in the placebo group (P =.94). One ulcer in each group was completely healed at study end. Levels of TIMP-1 increased significantly during FAP treatment. IL-8 concentration was significantly lower in wound fluid of healing ulcers than in the fluid of nonhealing ulcers, in both FAP and placebo groups. Growth factor levels were not modified with FAP treatment. CONCLUSION: Topical autologous platelets have no significant adjuvant effect on healing of chronic venous leg ulcers and increased wound fluid TIMP-1 concentration. Ulcer healing is associated with a decrease in wound fluid IL-8.     

Effect of apelin on glomerular hemodynamic function in the rat kidney

Apelin is a vasoactive peptide identified as the endogenous ligand of an orphan G protein-coupled receptor called APJ. Apelin and its receptor have been found in the brain and the cardiovascular system. Here we show that the apelin receptor mRNA is highly expressed in the glomeruli while its level of expression is lower in all nephron segments including collecting ducts that express vasopressin V2 receptors. Intravenous injection of apelin 17 into lactating rats induced a significant diuresis. Apelin receptor mRNA was also found in endothelial and vascular smooth muscle cells of glomerular arterioles. Apelin administration caused vasorelaxation of angiotensin II-preconstricted efferent and afferent arterioles as shown by an increase in their diameter. Activation of endothelial apelin receptors caused release of nitric oxide which inhibited angiotensin II-induced rise in intracellular calcium. In addition, it appears that apelin had a direct receptor-mediated vasoconstrictive effect on vascular smooth muscle. These results show that apelin has complex effects on the pre- and post glomerular microvasculature regulating renal hemodynamics. Its role on tubular function (if any) remains to be determined.     

Molecular absorbent recirculating system for the treatment of acute liver failure in surgical patients

The Molecular Adsorbent Recirculating System (MARS) represents an attractive artificial liver support system for the treatment of liver insufficiency. However, neither indications for MARS treatment (i.e., after extended liver resection) nor criteria for discontinuation of therapy have been evaluated. Therefore, we analyzed the clinical data of all our surgical patients who received MARS treatment for acute liver failure (n = 7). The aim of the study was to identify prognostic indicators for survival. Four of 174 patients resected for hepatic malignancy at our institution received a total of 13 MARS treatments. Two additional patients were successfully bridged to orthotopic liver transplantation with seven MARS treatments and one patient was MARS supported after liver transplantation of a steatotic graft with three MARS treatments. Five of the seven patients survived and were dismissed an average of 31 days, ranging from 17 to 47 days, after the final MARS treatment. No technical complications or adverse effects were observed during the MARS treatments. Important prognostic factors for hepatic recovery and survival were indocyanin green plasma disappearance rates greater than 5%/min and an increase in clotting factor V levels after each MARS treatment. We conclude that MARS therapy can be an effective treatment of postoperative liver insufficiency in the surgical hepatobiliary unit. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).     

Pelvic floor exercises for erectile dysfunction

OBJECTIVE: To examine the role of pelvic floor exercises as a way of restoring erectile function in men with erectile dysfunction. PATIENTS AND METHODS: In all, 55 men aged > 20 years who had experienced erectile dysfunction for > or = 6 months were recruited for a randomized controlled study with a cross-over arm. The men were treated with either pelvic floor muscle exercises (taught by a physiotherapist) with biofeedback and lifestyle changes (intervention group) or they were advised on lifestyle changes only (control group). Control patients who did not respond after 3 months were treated with the intervention. All men were given home exercises for a further 3 months. Outcomes were measured using the International Index of Erectile Function (IIEF), anal pressure measurements and independent (blinded) assessments. RESULTS: After 3 months, the erectile function of men in the intervention group was significantly better than in the control group (P < 0.001). Control patients who were given the intervention also significantly improved 3 months later (P < 0.001). After 6 months, blind assessment showed that 40% of men had regained normal erectile function, 35.5% improved but 24.5% failed to improve. CONCLUSION: This study suggests that pelvic floor exercises should be considered as a first-line approach for men seeking long-term resolution of their erectile dysfunction.     

Pathophysiology of obstructive sleep apnea

This article explores the physiologic basis and symptoms of obstructive sleep apnea--a general term encompassing central sleep apnea and obstructive sleep apnea. The former is relatively uncommon while the latter is much more common. Episodic collapse and blockage of the upper airway occur during sleep despite continuous respiratory effort. Three types of sleep obstructive breathing--apnea, hypopnea, and airway resistance--are associated with respiratory-related arousals from sleep.     

Assessment of fogging resistance of anti-fog personal eye protection

The propensity for occupational eye protectors to fog in warm and moist conditions is often offered as a reason by workers not to wear occupational eye protection even where mandatory eye protection areas have been specified. A study of eye protection practices in the New South Wales coal mining industry identified the number one issue in underground coal mine conditions as being fogging of eye safety wear. Conventional anti-fog treatments and cleaners were considered by the miners as completely inadequate in these conditions. At the time of the study claims were being made for a new generation of lens treatments. These merited evaluation. Spectacles and goggles claimed to be fog resistant were obtained from manufacturers and suppliers and subjected to the test set out in BS EN 168 and the compliance criterion of BS EN 166. Some lenses claimed to be fog resistant failed the requirement, some new technology lenses showed arguably superior performance but failed the criterion of the standard. Modifications to the test procedure of BS EN 168 and acceptance criteria of BS EN 166 are proposed.